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Extensibility of the fission surface power (FSP) system from the moon to Mars
Energy Technology Data Exchange (ETDEWEB)
Poston, David Irvin [Los Alamos National Laboratory
Fission reactors have great near-term potential to power human and robotic missions/outposts on the surface of the Moon and Mars (and potentially other planets, moons, and asteroids). The ability to provide a power-rich environment that is independent of solar intensity, nights, dust storms, etc., is of significant (perhaps enabling) importance to the further expansion of humans into our solar system. NASA's Reference Fission Surface Power (FSP) System is a 40 kWe system that has been primarily designed for lunar applications. This paper examines the extensibility of the FSP design and technology for potential missions on Mars. Possible impacts include the effects of changes in heat sink, gravity, day-night cycles, mission transit time, communication delay, and the chemistry of the regolith and atmosphere. One of the biggest impacts might be differences in the potential utilization of in-situ materials for shielding. Another major factor is that different missions will likely require different performance requirements, e.g. power, lifetime and mass. This paper concludes that the environmental differences between potential mission locations will not require significant changes in design and technologies, unless performance requirements for a specific mission are substantially different than those adopted for the FSP The primary basis for this conclusion is that the FSP has been designed with robust materials and design margins.
Capabilities and Testing of the Fission Surface Power Primary Test Circuit (FSP-PTC)
Garber, Anne E.
An actively pumped alkali metal flow circuit, designed and fabricated at the NASA Marshall Space Flight Center, is currently undergoing testing in the Early Flight Fission Test Facility (EFF-TF). Sodium potassium (NaK), which was used in the SNAP-10A fission reactor, was selected as the primary coolant. Basic circuit components include: simulated reactor core, NaK to gas heat exchanger, electromagnetic (EM) liquid metal pump, liquid metal flowmeter, load/drain reservoir, expansion reservoir, test section, and instrumentation. Operation of the circuit is based around a 37-pin partial-array core (pin and flow path dimensions are the same as those in a full core), designed to operate at 33 kWt. NaK flow rates of greater than 1 kg/sec may be achieved, depending upon the power applied to the EM pump. The heat exchanger provides for the removal of thermal energy from the circuit, simulating the presence of an energy conversion system. The presence of the test section increases the versatility of the circuit. A second liquid metal pump, an energy conversion system, and highly instrumented thermal simulators are all being considered for inclusion within the test section. This paper summarizes the capabilities and ongoing testing of the Fission Surface Power Primary Test Circuit (FSP-PTC).
Fission Surface Power Technology Development Status
Palac, Donald T.; Mason, Lee S.; Harlow, Scott
With the potential future deployment of a lunar outpost there is expected to be a clear need for a high-power, lunar surface power source to support lunar surface operations independent of the day-night cycle, and Fission Surface Power (FSP) is a very effective solution for power levels above a couple 10 s of kWe. FSP is similarly enabling for the poorly illuminated surface of Mars. The power levels/requirements for a lunar outpost option are currently being studied, but it is known that cost is clearly a predominant concern to decision makers. This paper describes the plans of NASA and the DOE to execute an affordable fission surface power system technology development project to demonstrate sufficient technology readiness of an affordable FSP system so viable and cost-effective FSP system options will be available when high power lunar surface system choices are expected to be made in the early 2010s.
Fission Surface Power System Initial Concept Definition
Under the NASA Exploration Technology Development Program (ETDP) and in partnership with the Department of Energy (DOE), NASA has embarked on a project to develop Fission Surface Power (FSP) technology. The primary goals of the project are to 1) develop FSP concepts that meet expected surface power requirements at reasonable cost with added benefits over other options, 2) establish a hardwarebased technical foundation for FSP design concepts and reduce overall development risk, 3) reduce the cost uncertainties for FSP and establish greater credibility for flight system cost estimates, and 4) generate the key products to allow NASA decision-makers to consider FSP as a preferred option for flight development. The FSP project was initiated in 2006 as the Prometheus Program and the Jupiter Icy Moons Orbiter (JIMO) mission were phased-out. As a first step, NASA Headquarters commissioned the Affordable Fission Surface Power System Study to evaluate the potential for an affordable FSP development approach. With a cost-effective FSP strategy identified, the FSP team evaluated design options and selected a Preliminary Reference Concept to guide technology development. Since then, the FSP Preliminary Reference Concept has served as a point-of-departure for several NASA mission architecture studies examining the use of nuclear power and has provided the foundation for a series of "Pathfinder" hardware tests. The long-term technology goal is a Technology Demonstration Unit (TDU) integrated system test using full-scale components and a non-nuclear reactor simulator. The FSP team consists of Glenn Research Center (GRC), Marshall Space Flight Center (MSFC) and the DOE National Laboratories at Los Alamos (LANL), Idaho (INL), Oak Ridge (ORNL), and Sandia (SNL). The project is organized into two main elements: Concept Definition and Risk Reduction. Under Concept Definition, the team performs trade studies, develops analytical tools, and formulates system concepts. Under Risk
The Role of Friction Stir Processing (FSP Parameters on TiC Reinforced Surface Al7075-T651 Aluminum Alloy
Directory of Open Access Journals (Sweden)
Felipe García-Vázquez
Full Text Available Abstract: Aluminum alloys are very promising for structural applications in aerospace, military and transportation industries due to their light weight, high strength-to-weight ratio and excellent resistance to corrosion. In comparison to unreinforced aluminum alloys, aluminum/aluminum alloy matrix composites reinforced with ceramic phases exhibit higher strength and hardness, improved tribological characteristics. A novel surface modifying technique, friction stir processing (FSP, has been developed for fabrication of surface composite with an improved performance. The effect of FSP parameters such as number of passes, direction of each pass, sealed or unsealed groove on microstructure was investigated. In this work, nano-particles of TiC (2% in weight were added to aluminum alloy AA7075-T651 to produce a functional surface. Fixed parameters for this AA7075 alloy were used; rotation speed of 1000 rpm, travel speed of 300 mm/min and pin penetration of 2.8 mm. Optical microscopy (OM, scanning electron microscopy (SEM and atomic force microscopy (AFM were employed to study the microstructure of the fabricated surface composites. The results indicated that the selected FSP parameters influenced the area of surface composite, distribution of TiC particles and micro-hardness of the surface composites. Finally, in order to evaluate rate wear the pin on disk test was carried out.
A Two-Phase Cooling Loop for Fission Surface Power Waste Heat Transport, Phase I
National Aeronautics and Space Administration — Current lunar-based Fission Surface Power (FSP) Systems that will support sustained surface outposts consist of a nuclear reactor with power converters, whose waste...
Parameter optimization and evaluation of mechanical and thermal properties of nanographene reinforced Al 6060 surface composite using FSP
Kalyanamanohar, V.; Appalachari, D. Gireesh Chandra
Friction stir processing (FSP) is emerging as a promising technique for making surface composites. FSP can improve surface properties such as hardness, strength, ductility, corrosion resistance, fatigue life and formability without affecting the bulk properties of the material. The literatures reported that FSP can produces very fine equiaxed and homogeneous grain structure for different Al alloys. Al 6060 is heat treatable alloy which has high thermal and electrical properties than remaining Al alloys. Al 6060 is being used where high rate of heat exchange is needed i.e. engine cylinders, heat exchangers etc. As derived from the carbon materials, like graphene and CNTs dissipates heat rapidly that improves the life of the engine cylinders and heat exchangers. In this work, nanographene is reinforced in the Al 6060 using friction stir processing at different rotational speeds, traverse speeds, and at constant load and tool tilt angle. After processed, the effect of process parameters on microstructure of the surface composite was investigated. The SEM studies shows that the FSP produces very fine and homogenous grain structure and it is observed that smaller grain size structure is obtained at lower traverse speed and higher rotational speeds. Significant improvement in ultimate tensile strength(22.9%) and hardness (22.44%) when compared friction stir processed plate at 1400 rotational speed and 20mm/min traverse speed with base Al 6060 plate. Coefficient of thermal expansion test of nanographene reinforced Al 6060 shows 7.33% decrease in its coefficient of thermal expansion as graphene has tendency to reduce the anisotropic nature.
Experimental Study and Response Surface Methodology for Investigation of FSP Process
Directory of Open Access Journals (Sweden)
Weglowski Marek Stanisław
Full Text Available W pracy przedstawiono wpływ predkosci obrotowej i przesuwu narzedzia oraz siły docisku na moment obrotowy działajacy na narzedzia w procesie tarciowej modyfikacji z mieszaniem materiału (FSP. Do wyznaczenia zaleznosci pomiedzy momentem a predkosciami obrotowa i przesuwu oraz siła docisku wykorzystano metode powierzchni odpowiedzi. Wykorzystano modele liniowy i kwadratowy uwzgledniajace interakcje pomiedzy parametrami wejsciowymi. Lepsze dopasowanie zapewnił model kwadratowy. Wyniki badan wykazały, iz wzrost predkosci obrotowej narzedzia powoduje zmniejszenie momentu działajacego na narzedzie, natomiast wzrost predkosci przesuwu i siły docisku powoduje wzrost momentu. Badania były przeprowadzone na odlewniczym stopie aluminium AlSi9Mg. Badania metalograficzne ujawniły, ze zastosowanie procesu FSP powoduje rozdrobnienie ziarna oraz redukcje porowatosci w obszarze mieszania. Wyrazna segregacja Si i Fe w materiale rodzimym została wyeliminowana, a rozkład pierwiastków jest bardziej jednorodny.
Ultra-Compact Heat Rejection System for Fission Surface Power, Phase I
National Aeronautics and Space Administration — Radiator panels are the baseline approach for rejecting waste heat from NASA Fission Surface Power (FSP) systems. The required panels are very large, which makes...
Integrated Surface Power Strategy for Mars
Rucker, Michelle
A National Aeronautics and Space Administration (NASA) study team evaluated surface power needs for a conceptual crewed 500-day Mars mission. This study had four goals: 1. Determine estimated surface power needed to support the reference mission; 2. Explore alternatives to minimize landed power system mass; 3. Explore alternatives to minimize Mars Lander power self-sufficiency burden; and 4. Explore alternatives to minimize power system handling and surface transportation mass. The study team concluded that Mars Ascent Vehicle (MAV) oxygen propellant production drives the overall surface power needed for the reference mission. Switching to multiple, small Kilopower fission systems can potentially save four to eight metric tons of landed mass, as compared to a single, large Fission Surface Power (FSP) concept. Breaking the power system up into modular packages creates new operational opportunities, with benefits ranging from reduced lander self-sufficiency for power, to extending the exploration distance from a single landing site. Although a large FSP trades well for operational complexity, a modular approach potentially allows Program Managers more flexibility to absorb late mission changes with less schedule or mass risk, better supports small precursor missions, and allows a program to slowly build up mission capability over time. A number of Kilopower disadvantages-and mitigation strategies-were also explored.
A Summary of NASA Architecture Studies Utilizing Fission Surface Power Technology
Mason, Lee S.; Poston, David I.
Beginning with the Exploration Systems Architecture Study in 2005, NASA has conducted various mission architecture studies to evaluate implementation options for the U.S. Space Policy. Several of the studies examined the use of Fission Surface Power (FSP) systems for human missions to the lunar and Martian surface. This paper summarizes the FSP concepts developed under four different NASA-sponsored architecture studies: Lunar Architecture Team, Mars Architecture Team, Lunar Surface Systems/Constellation Architecture Team, and International Architecture Working Group-Power Function Team.
Reference reactor module for NASA's lunar surface fission power system
International Nuclear Information System (INIS)
Poston, David I.; Kapernick, Richard J.; Dixon, David D.; Werner, James; Qualls, Louis; Radel, Ross
Surface fission power systems on the Moon and Mars may provide the first US application of fission reactor technology in space since 1965. The Affordable Fission Surface Power System (AFSPS) study was completed by NASA/DOE to determine the cost of a modest performance, low-technical risk surface power system. The AFSPS concept is now being further developed within the Fission Surface Power (FSP) Project, which is a near-term technology program to demonstrate system-level TRL-6 by 2013. This paper describes the reference FSP reactor module concept, which is designed to provide a net power of 40 kWe for 8 years on the lunar surface; note, the system has been designed with technologies that are fully compatible with a Martian surface application. The reactor concept uses stainless-steel based. UO 2 -fueled, pumped-NaK fission reactor coupled to free-piston Stirling converters. The reactor shielding approach utilizes both in-situ and launched shielding to keep the dose to astronauts much lower than the natural background radiation on the lunar surface. The ultimate goal of this work is to provide a 'workhorse' power system that NASA can utilize in near-term and future Lunar and Martian mission architectures, with the eventual capability to evolve to very high power, low mass systems, for either surface, deep space, and/or orbital missions.
Validation of FSP Reactor Design with Sensitivity Studies of Beryllium-Reflected Critical Assemblies
Energy Technology Data Exchange (ETDEWEB)
John D. Bess; Margaret A. Marshall
The baseline design for space nuclear power is a fission surface power (FSP) system: sodium-potassium (NaK) cooled, fast spectrum reactor with highly-enriched-uranium (HEU)-O2 fuel, stainless steel (SS) cladding, and beryllium reflectors with B4C control drums. Previous studies were performed to evaluate modeling capabilities and quantify uncertainties and biases associated with analysis methods and nuclear data. Comparison of Zero Power Plutonium Reactor (ZPPR)-20 benchmark experiments with the FSP design indicated that further reduction of the total design model uncertainty requires the reduction in uncertainties pertaining to beryllium and uranium cross-section data. Further comparison with three beryllium-reflected HEU-metal benchmark experiments performed at the Oak Ridge Critical Experiments Facility (ORCEF) concluded the requirement that experimental validation data have similar cross section sensitivities to those found in the FSP design. A series of critical experiments was performed at ORCEF in the 1960s to support the Medium Power Reactor Experiment (MPRE) space reactor design. The small, compact critical assembly (SCCA) experiments were graphite- or beryllium-reflected assemblies of SS-clad, HEU-O2 fuel on a vertical lift machine. All five configurations were evaluated as benchmarks. Two of the five configurations were beryllium reflected, and further evaluated using the sensitivity and uncertainty analysis capabilities of SCALE 6.1. Validation of the example FSP design model was successful in reducing the primary uncertainty constituent, the Be(n,n) reaction, from 0.28 %dk/k to 0.0004 %dk/k. Further assessment of additional reactor physics measurements performed on the SCCA experiments may serve to further validate FSP design and operation.
Fission Surface Power Technology Demonstration Unit Test Results
Briggs, Maxwell H.; Gibson, Marc A.; Geng, Steven M.; Sanzi, James L.
The Fission Surface Power (FSP) Technology Demonstration Unit (TDU) is a system-level demonstration of fission power technology intended for use on manned missions to Mars. The Baseline FSP systems consists of a 190 kWt UO2 fast-spectrum reactor cooled by a primary pumped liquid metal loop. This liquid metal loop transfers heat to two intermediate liquid metal loops designed to isolate fission products in the primary loop from the balance of plant. The intermediate liquid metal loops transfer heat to four Stirling Power Conversion Units (PCU), each of which produce 12 kWe (48 kW total) and reject waste heat to two pumped water loops, which transfer the waste heat to titanium-water heat pipe radiators. The FSP TDU simulates a single leg of the baseline FSP system using an electrically heater core simulator, a single liquid metal loop, a single PCU, and a pumped water loop which rejects the waste heat to a Facility Cooling System (FCS). When operated at the nominal operating conditions (modified for low liquid metal flow) during TDU testing the PCU produced 8.9 kW of power at an efficiency of 21.7 percent resulting in a net system power of 8.1 kW and a system level efficiency of 17.2 percent. The reduction in PCU power from levels seen during electrically heated testing is the result of insufficient heat transfer from the NaK heater head to the Stirling acceptor, which could not be tested at Sunpower prior to delivery to the NASA Glenn Research Center (GRC). The maximum PCU power of 10.4 kW was achieved at the maximum liquid metal temperature of 875 K, minimum water temperature of 350 K, 1.1 kg/s liquid metal flow, 0.39 kg/s water flow, and 15.0 mm amplitude at an efficiency of 23.3 percent. This resulted in a system net power of 9.7 kW and a system efficiency of 18.7 percent.
Testing of an Annular Linear Induction Pump for the Fission Surface Power Technology Demonstration Unit
Polzin, K. A.; Pearson, J. B.; Webster, K.; Godfoy, T. J.; Bossard, J. A.
Results of performance testing of an annular linear induction pump that has been designed for integration into a fission surface power technology demonstration unit are presented. The pump electromagnetically pushes liquid metal (NaK) through a specially-designed apparatus that permits quantification of pump performance over a range of operating conditions. Testing was conducted for frequencies of 40, 55, and 70 Hz, liquid metal temperatures of 125, 325, and 525 C, and input voltages from 30 to 120 V. Pump performance spanned a range of flow rates from roughly 0.3 to 3.1 L/s (4.8 to 49 gpm), and pressure heads of <1 to 104 kPa (<0.15 to 15 psi). The maximum efficiency measured during testing was 5.4%. At the technology demonstration unit operating temperature of 525 C the pump operated over a narrower envelope, with flow rates from 0.3 to 2.75 L/s (4.8 to 43.6 gpm), developed pressure heads from <1 to 55 kPa (<0.15 to 8 psi), and a maximum efficiency of 3.5%. The pump was supplied with three-phase power at 40 and 55 Hz using a variable-frequency motor drive, while power at 55 and 70 Hz was supplied using a variable-frequency power supply. Measured performance of the pump at 55 Hz using either supply exhibited good quantitative agreement. For a given temperature, the peak in efficiency occurred at different flow rates as the frequency was changed, but the maximum value of efficiency was relative insensitive within 0.3% over the frequency range tested, including a scan from 45 to 78 Hz. The objectives of the FSP technology project are as follows:5 • Develop FSP concepts that meet expected surface power requirements at reasonable cost with added benefits over other options. • Establish a nonnuclear hardware-based technical foundation for FSP design concepts to reduce overall development risk. • Reduce the cost uncertainties for FSP and establish greater credibility for flight system cost estimates. • Generate the key nonnuclear products to allow Agency
Reference reactor module for NASA's lunar surface fission power system
Energy Technology Data Exchange (ETDEWEB)
Poston, David I [Los Alamos National Laboratory; Kapernick, Richard J [Los Alamos National Laboratory; Dixon, David D [Los Alamos National Laboratory; Werner, James [INL; Qualls, Louis [ORNL; Radel, Ross [SNL
Surface fission power systems on the Moon and Mars may provide the first US application of fission reactor technology in space since 1965. The Affordable Fission Surface Power System (AFSPS) study was completed by NASA/DOE to determine the cost of a modest performance, low-technical risk surface power system. The AFSPS concept is now being further developed within the Fission Surface Power (FSP) Project, which is a near-term technology program to demonstrate system-level TRL-6 by 2013. This paper describes the reference FSP reactor module concept, which is designed to provide a net power of 40 kWe for 8 years on the lunar surface; note, the system has been designed with technologies that are fully compatible with a Martian surface application. The reactor concept uses stainless-steel based. UO{sub 2}-fueled, pumped-NaK fission reactor coupled to free-piston Stirling converters. The reactor shielding approach utilizes both in-situ and launched shielding to keep the dose to astronauts much lower than the natural background radiation on the lunar surface. The ultimate goal of this work is to provide a 'workhorse' power system that NASA can utilize in near-term and future Lunar and Martian mission architectures, with the eventual capability to evolve to very high power, low mass systems, for either surface, deep space, and/or orbital missions.
Biolistic transformation of the obligate plant pathogenic fungus, Erysiphe graminis f.sp. hordei
DEFF Research Database (Denmark)
Christiansen, S.K.; Knudsen, S.; Giese, H.
Particle gun acceleration appears to be a possible way to transform mycelium cells of obligate plant parasites growing on host surfaces, GUS expression was obtained in E. graminis f.sp. hordei cells after bombardment with the GUS gene under the control of the E. graminis f.sp. hordei beta...
Two-Nozzle Flame Spray Pyrolysis (FSP) Synthesis of CoMo/Al2O3 Hydrotreating Catalysts
DEFF Research Database (Denmark)
Høj, Martin; Pham, David K.; Brorson, Michael
synthesized oxidic catalysts were activated by sulfidation without further heat treatments. The hydrodesulfurization activity of the best two-nozzle FSP catalysts, compared to the one-nozzle FSP catalysts, improved from 75 to 91 % activity relative to a commercial reference catalyst...... at short flame mixing distances, where the flame conditions resemble one-nozzle FSP. Raman spectroscopy revealed that β-CoMoO4 was a component of all the catalysts (in the as-prepared oxidic form) together with alumina supported MoO x surface species. The only phase detected with XRD was γ-Al2O3. The FSP...
Testing of Liquid Metal Components for Nuclear Surface Power Systems
Polzin, K. A.; Pearson, J. B.; Godfroy, T. J.; Schoenfeld, M.; Webster, K.; Briggs, M. H.; Geng, S. M.; Adkins, H. E.; Werner, J. E.
The capability to perform testing at both the module/component level and in near prototypic reactor configurations using a non-nuclear test methodology allowed for evaluation of two components critical to the development of a potential nuclear fission power system for the lunar surface. A pair of 1 kW Stirling power convertors, similar to the type that would be used in a reactor system to convert heat to electricity, were integrated into a reactor simulator system to determine their performance using pumped NaK as the hot side working fluid. The performance in the pumped-NaK system met or exceed the baseline performance measurements where the converters were electrically heated. At the maximum hot-side temperature of 550 C the maximum output power was 2375 watts. A specially-designed test apparatus was fabricated and used to quantify the performance of an annular linear induction pump that is similar to the type that could be used to circulate liquid metal through the core of a space reactor system. The errors on the measurements were generally much smaller than the magnitude of the measurements, permitting accurate performance evaluation over a wide range of operating conditions. The pump produced flow rates spanning roughly 0.16 to 5.7 l/s (2.5 to 90 GPM), and delta p levels from less than 1 kPa to 90 kPa (greater than 0.145 psi to roughly 13 psi). At the nominal FSP system operating temperature of 525 C the maximum efficiency was just over 4%.
Scientific and computational challenges of the fusion simulation project (FSP)
Tang, W. M.
This paper highlights the scientific and computational challenges facing the Fusion Simulation Project (FSP). The primary objective is to develop advanced software designed to use leadership-class computers for carrying out multiscale physics simulations to provide information vital to delivering a realistic integrated fusion simulation model with unprecedented physics fidelity. This multiphysics capability will be unprecedented in that in the current FES applications domain, the largest-scale codes are used to carry out first-principles simulations of mostly individual phenomena in realistic 3D geometry while the integrated models are much smaller-scale, lower-dimensionality codes with significant empirical elements used for modeling and designing experiments. The FSP is expected to be the most up-to-date embodiment of the theoretical and experimental understanding of magnetically confined thermonuclear plasmas and to provide a living framework for the simulation of such plasmas as the associated physics understanding continues to advance over the next several decades. Substantive progress on answering the outstanding scientific questions in the field will drive the FSP toward its ultimate goal of developing a reliable ability to predict the behavior of plasma discharges in toroidal magnetic fusion devices on all relevant time and space scales. From a computational perspective, the fusion energy science application goal to produce high-fidelity, whole-device modeling capabilities will demand computing resources in the petascale range and beyond, together with the associated multicore algorithmic formulation needed to address burning plasma issues relevant to ITER — a multibillion dollar collaborative device involving seven international partners representing over half the world's population. Even more powerful exascale platforms will be needed to meet the future challenges of designing a demonstration fusion reactor (DEMO). Analogous to other major applied
Scientific and computational challenges of the fusion simulation project (FSP)
International Nuclear Information System (INIS)
Tang, W M
This paper highlights the scientific and computational challenges facing the Fusion Simulation Project (FSP). The primary objective is to develop advanced software designed to use leadership-class computers for carrying out multiscale physics simulations to provide information vital to delivering a realistic integrated fusion simulation model with unprecedented physics fidelity. This multiphysics capability will be unprecedented in that in the current FES applications domain, the largest-scale codes are used to carry out first-principles simulations of mostly individual phenomena in realistic 3D geometry while the integrated models are much smaller-scale, lower-dimensionality codes with significant empirical elements used for modeling and designing experiments. The FSP is expected to be the most up-to-date embodiment of the theoretical and experimental understanding of magnetically confined thermonuclear plasmas and to provide a living framework for the simulation of such plasmas as the associated physics understanding continues to advance over the next several decades. Substantive progress on answering the outstanding scientific questions in the field will drive the FSP toward its ultimate goal of developing a reliable ability to predict the behavior of plasma discharges in toroidal magnetic fusion devices on all relevant time and space scales. From a computational perspective, the fusion energy science application goal to produce high-fidelity, whole-device modeling capabilities will demand computing resources in the petascale range and beyond, together with the associated multicore algorithmic formulation needed to address burning plasma issues relevant to ITER - a multibillion dollar collaborative device involving seven international partners representing over half the world's population. Even more powerful exascale platforms will be needed to meet the future challenges of designing a demonstration fusion reactor (DEMO). Analogous to other major applied physics
Genetic diversity in Fusarium oxysporum f.sp. dianthi and F. redolens f.sp. dianthi
Baayen, R.P.; Dreven, van F.; Krijger, M.C.; Waalwijk, C.
Pathogenic isolates were selected representing all known vegetative compatibility groups (VCGs) and races of Fusarium oxysporum sensu lato from Dianthus spp. On basis of differences in the internal transcribed spacer region of the ribosomal DNA, six VCGs were classified as F. oxysporum f.sp. dianthi
Scientific and Computational Challenges of the Fusion Simulation Program (FSP)
International Nuclear Information System (INIS)
Tang, William M.
This paper highlights the scientific and computational challenges facing the Fusion Simulation Program (FSP) a major national initiative in the United States with the primary objective being to enable scientific discovery of important new plasma phenomena with associated understanding that emerges only upon integration. This requires developing a predictive integrated simulation capability for magnetically-confined fusion plasmas that are properly validated against experiments in regimes relevant for producing practical fusion energy. It is expected to provide a suite of advanced modeling tools for reliably predicting fusion device behavior with comprehensive and targeted science-based simulations of nonlinearly-coupled phenomena in the core plasma, edge plasma, and wall region on time and space scales required for fusion energy production. As such, it will strive to embody the most current theoretical and experimental understanding of magnetic fusion plasmas and to provide a living framework for the simulation of such plasmas as the associated physics understanding continues to advance over the next several decades. Substantive progress on answering the outstanding scientific questions in the field will drive the FSP toward its ultimate goal of developing the ability to predict the behavior of plasma discharges in toroidal magnetic fusion devices with high physics fidelity on all relevant time and space scales. From a computational perspective, this will demand computing resources in the petascale range and beyond together with the associated multi-core algorithmic formulation needed to address burning plasma issues relevant to ITER - a multibillion dollar collaborative experiment involving seven international partners representing over half the world's population. Even more powerful exascale platforms will be needed to meet the future challenges of designing a demonstration fusion reactor (DEMO). Analogous to other major applied physics modeling projects (e
Scientific and Computational Challenges of the Fusion Simulation Program (FSP)
Energy Technology Data Exchange (ETDEWEB)
William M. Tang
This paper highlights the scientific and computational challenges facing the Fusion Simulation Program (FSP) a major national initiative in the United States with the primary objective being to enable scientific discovery of important new plasma phenomena with associated understanding that emerges only upon integration. This requires developing a predictive integrated simulation capability for magnetically-confined fusion plasmas that are properly validated against experiments in regimes relevant for producing practical fusion energy. It is expected to provide a suite of advanced modeling tools for reliably predicting fusion device behavior with comprehensive and targeted science-based simulations of nonlinearly-coupled phenomena in the core plasma, edge plasma, and wall region on time and space scales required for fusion energy production. As such, it will strive to embody the most current theoretical and experimental understanding of magnetic fusion plasmas and to provide a living framework for the simulation of such plasmas as the associated physics understanding continues to advance over the next several decades. Substantive progress on answering the outstanding scientific questions in the field will drive the FSP toward its ultimate goal of developing the ability to predict the behavior of plasma discharges in toroidal magnetic fusion devices with high physics fidelity on all relevant time and space scales. From a computational perspective, this will demand computing resources in the petascale range and beyond together with the associated multi-core algorithmic formulation needed to address burning plasma issues relevant to ITER - a multibillion dollar collaborative experiment involving seven international partners representing over half the world's population. Even more powerful exascale platforms will be needed to meet the future challenges of designing a demonstration fusion reactor (DEMO). Analogous to other major applied physics modeling projects (e
Friction stir processing (FSP: refining microstructures and improving properties
Directory of Open Access Journals (Sweden)
McNelley, T. R.
Full Text Available FSP is reviewed as an allied technology of friction stir welding (FSW and additional considerations such as processing pattern and step over distance are introduced. The application of FSP to continuously cast AA5083 material in the as-cast condition is described and the extent of grain refinement and homogenization of microstructure is documented. The FSP-induced superplastic response of this material is compared to the response of conventionally processed AA5083 and the improved ductility of the FSP material is related to grain refinement and microstructure homogenization.
Se revisa el procesado por fricción batida (FSP como un aliado tecnológico de la soldadura por fricción batida (FSW y se introducen consideraciones adicionales tales como el patrón de procesado y el paso en función de la distancia. Se describe la aplicación de FSP al material AA5083 por colada continua en la condición de colada y se documenta el grado de afino de grano y homogeneización de la microestructura. La respuesta de superplasticidad inducida por FSP se compara con la respuesta de la aleación AA5083 procesada convencionalmente y la mejora de ductilidad del material FSP se relaciona con el afino de grano y la homogeneización de la microestructura.
Flame spray pyrolysis (FSP) for synthesis of nanoparticles
International Nuclear Information System (INIS)
Maedler, L.; Pratsinis, S.E.
Bismuth oxide is used as additive in paints and in cataphoresis, and as substitute for lead oxide in glass or porcelain. The presence of a small amount of Bi 2 O 3 in calcined ZnO ceramics promotes non-linear current voltage characteristics that are used in varistor production. Also tin oxide based gas sensors for carbon monoxide, exhibit improved sensitivity and selectivity when doped with Bi 2 O 3 . Furthermore, the total oxidation of isobutene is enhanced on bismuth containing tin oxide catalysts. Bismuth oxide itself serves also as catalyst for conversion of propylene to 1,5 hexadiene and can be regenerated when supported on α-Al 2 O 3 . In electrolyte, varistor, sensor and catalyst applications high purity and small Bi 2 O 3 particles with controlled morphology are required. Especially in catalysts the available surface area (below 17 m 2 /g) of Bi 2 O 3 limits applications at the moment. Typically, Bi 2 O 3 is prepared by oxidation of bismuth metal at 750-800 deg C or by thermal decomposition of carbonates or by addition of alkali-metal hydroxides to a bismuth salt solution. High temperature synthesis of Bi 2 O 3 from precursor gases was proposed by Liu and Kleinschmit using the established Aerosil route of reacting chloride precursors in a hydrogen / air (or oxygen) flame, but the volatility of the starting materials poses the most severe limitation. Suzuki et al. prepared spherical bismuth oxide particles of about 26 nm in diameter by the ICP-method. Spraying an aqueous bismuth nitrate solution into a hot wall reactor resulted in Bi 2 O 3 particles of about 100 nm in diameter. Here, synthesis of bismuth oxide nanoparticles is investigated by flame spray pyrolysis (FSP) as flame technology is used for manufacture of oxide commodities and as such FSP has high potential for manufacture of oxide nanoparticles. The FSP process, in particular, has the ability to synthesize metal oxides and mixed metal oxides of high purity at high production rates and under
Fission Surface Power Technology Development Status
Palac, Donald T.; Mason, Lee S.; Houts, Michael G.; Harlow, Scott
Power is a critical consideration in planning exploration of the surfaces of the Moon, Mars, and beyond. Nuclear power is an important option, especially for locations in the solar system where sunlight is limited in availability or intensity. NASA is maintaining the option for fission surface power for the Moon and Mars by developing and demonstrating technology for an affordable fission surface power system. Because affordability drove the determination of the system concept that this technology will make possible, low development and recurring costs result, while required safety standards are maintained. However, an affordable approach to fission surface power also provides the benefits of simplicity, robustness, and conservatism in design. This paper will illuminate the multiplicity of benefits to an affordable approach to fission surface power, and will describe how the foundation for these benefits is being developed and demonstrated in the Exploration Technology Development Program s Fission Surface Power Project.
Fission Surface Power Technology Development Update
Palac, Donald T.; Mason, Lee S.; Houts, Michael G.; Harlow, Scott
Power is a critical consideration in planning exploration of the surfaces of the Moon, Mars, and places beyond. Nuclear power is an important option, especially for locations in the solar system where sunlight is limited or environmental conditions are challenging (e.g., extreme cold, dust storms). NASA and the Department of Energy are maintaining the option for fission surface power for the Moon and Mars by developing and demonstrating technology for a fission surface power system. The Fission Surface Power Systems project has focused on subscale component and subsystem demonstrations to address the feasibility of a low-risk, low-cost approach to space nuclear power for surface missions. Laboratory demonstrations of the liquid metal pump, reactor control drum drive, power conversion, heat rejection, and power management and distribution technologies have validated that the fundamental characteristics and performance of these components and subsystems are consistent with a Fission Surface Power preliminary reference concept. In addition, subscale versions of a non-nuclear reactor simulator, using electric resistance heating in place of the reactor fuel, have been built and operated with liquid metal sodium-potassium and helium/xenon gas heat transfer loops, demonstrating the viability of establishing system-level performance and characteristics of fission surface power technologies without requiring a nuclear reactor. While some component and subsystem testing will continue through 2011 and beyond, the results to date provide sufficient confidence to proceed with system level technology readiness demonstration. To demonstrate the system level readiness of fission surface power in an operationally relevant environment (the primary goal of the Fission Surface Power Systems project), a full scale, 1/4 power Technology Demonstration Unit (TDU) is under development. The TDU will consist of a non-nuclear reactor simulator, a sodium-potassium heat transfer loop, a power
Optimization of process parameters for friction stir processing (FSP ...
Indian Academy of Sciences (India)
An Al-5 wt% TiC composite was processed in situ using K2TiF6 and graphite in Al melt and subjected to FSP. Processing parameters for FSP were optimized to get a defect free stir zone and homogenize the particle distribution. It was found that a rotation speed > 800 rpm is needed. A rotation speed of 1000 rpm and a ...
Optimization of process parameters for friction stir processing (FSP ...
Indian Academy of Sciences (India)
An Al-5 wt% TiC composite was processed in situ using K2TiF6 and graphite in Al melt and subjected to FSP. Processing .... Optimization of process parameters for friction stir processing of Al–TiC in situ composite. 573. Table 1. FSP process ... (Model 3367) at a strain rate of 10–3 s–1. 3. Results and discussion. 3.1 XRD ...
Human Mars Surface Mission Nuclear Power Considerations
Rucker, Michelle A.
A key decision facing Mars mission designers is how to power a crewed surface field station. Unlike the solar-powered Mars Exploration Rovers (MER) that could retreat to a very low power state during a Martian dust storm, human Mars surface missions are estimated to need at least 15 kilowatts of electrical (kWe) power simply to maintain critical life support and spacecraft functions. 'Hotel' loads alone for a pressurized crew rover approach two kWe; driving requires another five kWe-well beyond what the Curiosity rover's Radioisotope Power System (RPS) was designed to deliver. Full operation of a four-crew Mars field station is estimated at about 40 kWe. Clearly, a crewed Mars field station will require a substantial and reliable power source, beyond the scale of robotic mission experience. This paper explores the applications for both fission and RPS nuclear options for Mars.
Solar Versus Fission Surface Power for Mars
Rucker, Michelle A.; Oleson, Steve; George, Pat; Landis, Geoffrey A.; Fincannon, James; Bogner, Amee; Jones, Robert E.; Turnbull, Elizabeth; McNatt, Jeremiah; Martini, Michael C.;
A multi-discipline team of experts from the National Aeronautics and Space Administration (NASA) developed Mars surface power system point design solutions for two conceptual missions to Mars using In-situ resource utilization (ISRU). The primary goal of this study was to compare the relative merits of solar- versus fission-powered versions of each surface mission. First, the team compared three different solar-power options against a fission power system concept for a sub-scale, uncrewed demonstration mission. This "pathfinder" design utilized a 4.5 meter diameter lander. Its primary mission would be to demonstrate Mars entry, descent, and landing techniques. Once on the Martian surface, the lander's ISRU payload would demonstrate liquid oxygen propellant production from atmospheric resources. For the purpose of this exercise, location was assumed to be at the Martian equator. The three solar concepts considered included a system that only operated during daylight hours (at roughly half the daily propellant production rate of a round-the-clock fission design), a battery-augmented system that operated through the night (matching the fission concept's propellant production rate), and a system that operated only during daylight, but at a higher rate (again, matching the fission concept's propellant production rate). Including 30% mass growth allowance, total payload masses for the three solar concepts ranged from 1,128 to 2,425 kg, versus the 2,751 kg fission power scheme. However, solar power masses increase as landing sites are selected further from the equator, making landing site selection a key driver in the final power system decision. The team also noted that detailed reliability analysis should be performed on daytime-only solar power schemes to assess potential issues with frequent ISRU system on/off cycling.
Solar vs. Fission Surface Power for Mars
Rucker, Michelle A.; Oleson, Steve; George, Pat; Landis, Geoffrey A.; Fincannon, James; Bogner, Amee; Jones, Robert E.; Turnbull, Elizabeth; Martini, Michael C.; Gyekenyesi, John Z.;
A multi-discipline team of experts from the National Aeronautics and Space Administration (NASA) developed Mars surface power system point design solutions for two conceptual missions. The primary goal of this study was to compare the relative merits of solar- versus fission-powered versions of each surface mission. First, the team compared three different solar power options against a fission power system concept for a sub-scale, uncrewed demonstration mission. The 4.5 meter (m) diameter pathfinder lander's primary mission would be to demonstrate Mars entry, descent, and landing techniques. Once on the Martian surface, the lander's In Situ Resource Utilization (ISRU) payload would demonstrate liquid oxygen propellant production using atmospheric resources. For the purpose of this exercise, location was assumed to be at the Martian equator. The three solar concepts considered included a system that only operated during daylight hours (at roughly half the daily propellant production rate of a round-the-clock fission design), a battery-augmented system that operated through the night (matching the fission concept's propellant production rate), and a system that operated only during daylight, but at a higher rate (again, matching the fission concept's propellant production rate). Including 30% mass growth allowance, total payload masses for the three solar concepts ranged from 1,116 to 2,396 kg, versus the 2,686 kg fission power scheme. However, solar power masses are expected to approach or exceed the fission payload mass at landing sites further from the equator, making landing site selection a key driver in the final power system decision. The team also noted that detailed reliability analysis should be performed on daytime-only solar power schemes to assess potential issues with frequent ISRU system on/off cycling. Next, the team developed a solar-powered point design solution for a conceptual four-crew, 500-day surface mission consisting of up to four landers per
FSP1(+) fibroblast subpopulation is essential for the maintenance and regeneration of medullary thymic epithelial cells.
Sun, Lina; Sun, Chenming; Liang, Zhanfeng; Li, Hongran; Chen, Lin; Luo, Haiying; Zhang, Hongmei; Ding, Pengbo; Sun, Xiaoning; Qin, Zhihai; Zhao, Yong
Thymic epithelial cells (TECs) form a 3-dimentional network supporting thymocyte development and maturation. Besides epithelium and thymocytes, heterogeneous fibroblasts are essential components in maintaining thymic microenvironments. However, thymic fibroblast characteristics, development and function remain to be determined. We herein found that thymic non-hematopoietic CD45(-)FSP1(+) cells represent a unique Fibroblast specific protein 1 (FSP1)(-)fibroblast-derived cell subset. Deletion of these cells in FSP1-TK transgenic mice caused thymus atrophy due to the loss of TECs, especially mature medullary TECs (MHCII(high), CD80(+) and Aire(+)). In a cyclophosphamide-induced thymus injury and regeneration model, lack of non-hematopoietic CD45(-)FSP1(+) fibroblast subpopulation significantly delayed thymus regeneration. In fact, thymic FSP1(+) fibroblasts released more IL-6, FGF7 and FSP1 in the culture medium than their FSP1(-) counterparts. Further experiments showed that the FSP1 protein could directly enhance the proliferation and maturation of TECs in the in vitro culture systems. FSP1 knockout mice had significantly smaller thymus size and less TECs than their control. Collectively, our studies reveal that thymic CD45(-)FSP1(+) cells are a subpopulation of fibroblasts, which is crucial for the maintenance and regeneration of TECs especially medullary TECs through providing IL-6, FGF7 and FSP1.
Power productivity of the ground surface
Directory of Open Access Journals (Sweden)
Gutu A.I.
Full Text Available Here there is presented an attempt to estimate the efficiency degree when working with soil surface through the different methods of valorization incident solar radiation. Such technical methods are being analyzed as (solar collectors, photovoltaic cells, solar thermal power plants, power cultures field (bushes, wheat, sunflower, maize, rape, sorghum as well as microalgae crops. Here is the description of advantages and disadvantages for each group in part out of these three. The technical methods are up to date from the efficiency utilization view-point of industrial area. Microalgae crops are similar to technical methods from this point of view.
Lunar surface fission power supplies: Radiation issues
International Nuclear Information System (INIS)
Houts, M.G.; Lee, S.K.
A lunar space fission power supply shield that uses a combination of lunar regolith and materials brought from earth may be optimal for early lunar outposts and bases. This type of shield can be designed such that the fission power supply does not have to be moved from its landing configuration, minimizing handling and required equipment on the lunar surface. Mechanisms for removing heat from the lunar regolith are built into the shield, and can be tested on earth. Regolith activation is greatly reduced compared with a shield that uses only regolith, and it is possible to keep the thermal conditions of the fission power supply close to those seen in free space. For a well designed shield, the additional mass required to be brought from earth should be less than 1,000 kg. Detailed radiation transport calculations confirm the feasibility of such a shield
Power System for Venus Surface Exploration
Landis, Geoffrey A.; Mellott, Kenneth
A radioisotope power and cooling system is designed to provide electrical power for a probe operating on the surface of Venus. Most foreseeable electronics devices and sensors cannot operate at the 450 C ambient surface temperature of Venus. Because the mission duration is substantially long and the use of thermal mass to maintain an operable temperature range is likely impractical, some type of active refrigeration may be required to keep electronic components at a temperature below ambient. The fundamental cooling parameters are the cold sink temperature, the hot sink temperature, and the amount of heat to be removed. In this instance, it is anticipated that electronics would have a nominal operating temperature of 300 C. Due to the highly thermal convective nature of the high-density (90 bar CO2) atmosphere, the hot sink temperature was assumed to be 50 C, which provided a 500 C temperature of the cooler's heat rejecter to the ambient atmosphere. The majority of the heat load on the cooler is from the high temperature ambient surface environment on Venus, with a small contribution of heat generation from electronics and sensors. Both thermoelectric (RTG) and dynamic power conversion systems were analyzed, based on use of a standard isotope (General-purpose heat source, or GPHS) brick. For the radioisotope Stirling power converter configuration designed, the Sage model predicts a thermodynamic power output capacity of 478.1 watts, which slightly exceeds the required 469.1 watts. The hot sink temperature is 1200 C, and the cold sink temperature is 500 C. The required heat input is 1740 watts. This gives a thermodynamic efficiency of 27.48 %. It is estimated that the mechanical efficiency of the power converter design is on the order of 85 %, based on experimental measurements taken from 500-watt power class, laboratory-tested Stirling engines. The overall efficiency is calculated to be 23.36 %. The mass of the power converter is estimated at approximately 21.6 kg
Venus Surface Power and Cooling System Design
Landis, Geoffrey A.; Mellott, Kenneth D.
A radioisotope power and cooling system is designed to provide electrical power for the a probe operating on the surface of Venus. Most foreseeable electronics devices and sensors simply cannot operate at the 450 C ambient surface temperature of Venus. Because the mission duration is substantially long and the use of thermal mass to maintain an operable temperature range is likely impractical, some type of active refrigeration may be required to keep certain components at a temperature below ambient. The fundamental cooling requirements are comprised of the cold sink temperature, the hot sink temperature, and the amount of heat to be removed. In this instance, it is anticipated that electronics would have a nominal operating temperature of 300 C. Due to the highly thermal convective nature of the high-density atmosphere, the hot sink temperature was assumed to be 50 C, which provided a 500 C temperature of the cooler's heat rejecter to the ambient atmosphere. The majority of the heat load on the cooler is from the high temperature ambient surface environment on Venus. Assuming 5 cm radial thickness of ceramic blanket insulation, the ambient heat load was estimated at approximately 77 watts. With an estimated quantity of 10 watts of heat generation from electronics and sensors, and to accommodate some level of uncertainty, the total heat load requirement was rounded up to an even 100 watts. For the radioisotope Stirling power converter configuration designed, the Sage model predicts a thermodynamic power output capacity of 478.1 watts, which slightly exceeds the required 469.1 watts. The hot sink temperature is 1200 C, and the cold sink temperature is 500 C. The required heat input is 1740 watts. This gives a thermodynamic efficiency of 27.48 %. The maximum theoretically obtainable efficiency is 47.52 %. It is estimated that the mechanical efficiency of the power converter design is on the order of 85 %, based on experimental measurements taken from 500 watt power
Energy Technology Data Exchange (ETDEWEB)
Hawkes, Grant L.; Jones, Warren F.; Marcum, Wade; Weiss, Aaron; Howard, Trevor
The U.S. High Performance Research Reactor Conversions fuel development team is focused on developing and qualifying the uranium-molybdenum (U-Mo) alloy monolithic fuel to support conversion of domestic research reactors to low enriched uranium. Several previous irradiations have demonstrated the favorable behavior of the monolithic fuel. The Full Scale Plate 1 (FSP-1) fuel plate experiment will be irradiated in the northeast (NE) flux trap of the Advanced Test Reactor (ATR). This fueled experiment contains six aluminum-clad fuel plates consisting of monolithic U-Mo fuel meat. Flow testing experimentation and hydraulic analysis have been performed on the FSP-1 experiment to be irradiated in the ATR at the Idaho National Laboratory (INL). A flow test experiment mockup of the FSP-1 experiment was completed at Oregon State University. Results of several flow test experiments are compared with analyses. This paper reports and shows hydraulic analyses are nearly identical to the flow test results. A water velocity of 14.0 meters per second is targeted between the fuel plates. Comparisons between FSP-1 measurements and this target will be discussed. This flow rate dominates the flow characteristics of the experiment and model. Separate branch flows have minimal effect on the overall experiment. A square flow orifice was placed to control the flowrate through the experiment. Four different orifices were tested. A flow versus delta P curve for each orifice is reported herein. Fuel plates with depleted uranium in the fuel meat zone were used in one of the flow tests. This test was performed to evaluate flow test vibration with actual fuel meat densities and reported herein. Fuel plate deformation tests were also performed and reported.
The FSP Boundary Science Driver Plan
Energy Technology Data Exchange (ETDEWEB)
Rognlien, T. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Whyte, D. G. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Brooks, J. N. [Purdue Univ., West Lafayette, IN (United States); Canik, J. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Greenwald, M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Stotler, D. P. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Tang, X. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tautges, T. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Wirth, B. D. [Univ. of Tennessee, Knoxville, TN (United States)
This report describes the boundary region in a fusion device. This includes a narrow region where plasma parameters change very rapidly and the near surface of adjoining materials know as plasma-facing components.
FSP27 promotes lipid droplet clustering and then fusion to regulate triglyceride accumulation.
Directory of Open Access Journals (Sweden)
Srikarthika Jambunathan
Full Text Available Fat Specific Protein 27 (FSP27, a lipid droplet (LD associated protein in adipocytes, regulates triglyceride (TG storage. In the present study we demonstrate that FSP27 plays a key role in LD morphology to accumulate TGs. We show here that FSP27 promotes clustering of the LDs which is followed by their fusion into fewer and enlarged droplets. To map the domains of FSP27 responsible for these events, we generated GFP-fusion constructs of deletion mutants of FSP27. Microscopic analysis revealed that amino acids 173-220 of FSP27 are necessary and sufficient for both the targeting of FSP27 to LDs and the initial clustering of the droplets. Amino acids 120-140 are essential but not sufficient for LD enlargement, whereas amino acids 120-210 are necessary and sufficient for both clustering and fusion of LDs to form enlarged droplets. In addition, we found that FSP27-mediated enlargement of LDs, but not their clustering, is associated with triglyceride accumulation. These results suggest a model in which FSP27 facilitates LD clustering and then promotes their fusion to form enlarged droplets in two discrete, sequential steps, and a subsequent triglyceride accumulation.
Surface processing by high power excimer laser
International Nuclear Information System (INIS)
Stehle, M.
Surface processing with lasers is a promising field of research and applications because lasers bring substantial advantages : laser beams work at distance, laser treatments are clean in respect of environment consideration and they offer innovative capabilities for surface treatment which cannot be reached by other way. Excimer lasers are pulsed, gaseous lasers which emit in UV spectral range - the most common are XeCl (308 nm), KrF (248 nm), ArF (193 nm). From 1980 up to 1994, many of them have been used for research, medical and industrial applications such as spectroscopy, PRK (photo-refractive keratotomy) and micro-machining. In the last six years, from 1987 up to 1993, efforts have been done in order to jump from 100 W average power up to 1 kW for XeCl laser at λ = 308 nm. It was the aim of AMMTRA project in Japan as EU205 and EU213 Eureka projects in Europe. In this framework, SOPRA developed VEL (Very large Excimer Laser). In 1992, 1 kW (10 J x 100 Hz) millstone has been reached for the first time, this technology is based on X-Ray preionization and large laser medium (5 liters). Surface treatments based on this laser source are the main purpose of VEL Lasers. Some of them are given for instance : a) Turbine blades made with metallic substrate and ceramic coatings on the top, are glazed in order to increase corrosion resistance of ceramic and metal sandwich. b) Selective ablation of organic coatings deposited on fragile composite material is investigated in Aerospace industry. c) Chock hardening of bulk metallic materials or alloys are investigated for automotive industry in order to increase wear resistance. d) Ablation of thin surface oxides of polluted steels are under investigation in nuclear industry for decontamination. (J.P.N.)
Intermittent fasting up-regulates Fsp27/Cidec gene expression in white adipose tissue.
Karbowska, Joanna; Kochan, Zdzislaw
Fat-specific protein of 27 kDa (FSP27) is a novel lipid droplet protein that promotes triacylglycerol storage in white adipose tissue (WAT). The regulation of the Fsp27 gene expression in WAT is largely unknown. We investigated the nutritional regulation of FSP27 in WAT. The effects of intermittent fasting (48 d, eight cycles of 3-d fasting and 3-d refeeding), caloric restriction (48 d), fasting-refeeding (3-d fasting and 3-d refeeding), and fasting (3 d) on mRNA expression of FSP27, peroxisome proliferator-activated receptor γ (PPARγ2), CCAAT/enhancer binding protein α (C/EBPα), and M isoform of carnitine palmitoyltransferase 1 (a positive control for PPARγ activation) in epididymal WAT and on serum triacylglycerol, insulin, and leptin levels were determined in Wistar rats. We also determined the effects of PPARγ activation by rosiglitazone or pioglitazone on FSP27 mRNA levels in primary rat adipocytes. Long-term intermittent fasting, in contrast to other dietary manipulations, significantly up-regulated Fsp27 gene expression in WAT. Moreover, in rats subjected to intermittent fasting, serum insulin levels were elevated; PPARγ2 and C/EBPα mRNA expression in WAT was increased, and there was a positive correlation of Fsp27 gene expression with PPARγ2 and C/EBPα mRNA levels. FSP27 mRNA expression was also increased in adipocytes treated with PPARγ agonists. Our study demonstrates that the transcription of the Fsp27 gene in adipose tissue may be induced in response to nutritional stimuli. Furthermore, PPARγ2, C/EBPα, and insulin may be involved in the nutritional regulation of FSP27. Thus intermittent fasting, despite lower caloric intake, may promote triacylglycerol deposition in WAT by increasing the expression of genes involved in lipid storage, such as Fsp27. Copyright © 2012 Elsevier Inc. All rights reserved.
Comparison of Fusarium oxysporum fsp lycopersici races 1, 2 and 3 ...
African Journals Online (AJOL)
Dr J. T. Ekanem
Fusarium oxysporum fsp lycoperisci and fsp radicis lycopersici was carried out using the big dye terminator ... types, or forma speciales and races of Fusarium ..... Yamaguchi, I. (1997) Gel Penetrate- blotted immunobinding assay, a novel method for serological detection of. Fusarium spp in soil. J. Pestic. Sci. 22:321-. 325. 6.
High Temperature Surface Parameters for Solar Power
National Research Council Canada - National Science Library
Butler, C. F; Jenkins, R. J; Rudkin, R. L; Laughridge, F. I
... at a given distance from the sun. Thermal conversion efficiencies with a concentration ratio of 50 have been computed for each surface when exposed to solar radiation at the Earth's mean orbital radius...
The powerful pulsed electron beam effect on the metallic surfaces
International Nuclear Information System (INIS)
Neklyudov, I.M.; Yuferov, V.B.; Kosik, N.A.; Druj, O.S.; Skibenko, E.I.
Experimental results of the influence of powerful pulsed electron beams on the surface structure,hardness and corrosion resistance of the Cr18ni10ti steel are presented. The experiments were carried out in the powerful electron accelerators of directional effect VGIK-1 and DIN-2K with an energy up to approx 300 KeV and a power density of 10 9 - 10 11 W/cm 2 for micro- and nanosecond range. The essential influence of the irradiation power density on the material structure was established. Pulsed powerful beam action on metallic surface leads to surface melting,modification of the structure and structure-dependent material properties. The gas emission and mass-spectrometer analysis of the beam-surface interaction were defined
Performance Testing of a Liquid Metal Pump for In-Space Power Systems
Polzin, Kurt
Fission surface power (FSP) systems could be used to provide power on the surface of the moon, Mars, or other planets and moons of our solar system. Fission power systems could provide excellent performance at any location, including those near the poles or other permanently shaded regions, and offer the capability to provide on demand power at any time, even at large distances from the sun. Fission-based systems also offer the potential for outposts, crew and science instruments to operate in a power-rich environment. NASA has been exploring technologies with the goal of reducing the cost and technical risk of employing FSP systems. A reference 40 kWe option has been devised that is cost-competitive with alternatives while providing more power for less mass anywhere on the lunar surface. The reference FSP system is also readily extensible for use on Mars, where it would be capable of operating through global dust storms and providing year-round power at any Martian latitude. Detailed development of the FSP concept and the reference mission are documented in various other reports. The development discussed in this paper prepares the way for testing of the Technology Demonstration Unit (TDU), which is a 10 kWe end-to-end test of FSP technologies intended to raise the entire FSP system to technology readiness level (TRL) 6. The Early Flight Fission Test Facility (EFF-TF) was established by NASA s Marshall Space Flight Center (MSFC) to provide a capability for performing hardware-directed activities to support multiple in-space nuclear reactor concepts by using a nonnuclear test methodology. This includes fabrication and testing at both the module/component level and at near prototypic reactor components and configurations allowing for realistic thermal-hydraulic evaluations of systems. The liquid-metal pump associated with the FSP system must be compatible with the liquid NaK coolant and have adequate performance to enable a viable flight system. Idaho National
Small reactor power systems for manned planetary surface bases
Bloomfield, Harvey S.
A preliminary feasibility study of the potential application of small nuclear reactor space power systems to manned planetary surface base missions was conducted. The purpose of the study was to identify and assess the technology, performance, and safety issues associated with integration of reactor power systems with an evolutionary manned planetary surface exploration scenario. The requirements and characteristics of a variety of human-rated modular reactor power system configurations selected for a range of power levels from 25 kWe to hundreds of kilowatts is described. Trade-off analyses for reactor power systems utilizing both man-made and indigenous shielding materials are provided to examine performance, installation and operational safety feasibility issues. The results of this study have confirmed the preliminary feasibility of a wide variety of small reactor power plant configurations for growth oriented manned planetary surface exploration missions. The capability for power level growth with increasing manned presence, while maintaining safe radiation levels, was favorably assessed for nominal 25 to 100 kWe modular configurations. No feasibility limitations or technical barriers were identified and the use of both distance and indigenous planetary soil material for human rated radiation shielding were shown to be viable and attractive options.
Simulation of a Lunar Surface Base Power Distribution Network for the Constellation Lunar Surface Systems
Mintz, Toby; Maslowski, Edward A.; Colozza, Anthony; McFarland, Willard; Prokopius, Kevin P.; George, Patrick J.; Hussey, Sam W.
The Lunar Surface Power Distribution Network Study team worked to define, breadboard, build and test an electrical power distribution system consistent with NASA's goal of providing electrical power to sustain life and power equipment used to explore the lunar surface. A testbed was set up to simulate the connection of different power sources and loads together to form a mini-grid and gain an understanding of how the power systems would interact. Within the power distribution scheme, each power source contributes to the grid in an independent manner without communication among the power sources and without a master-slave scenario. The grid consisted of four separate power sources and the accompanying power conditioning equipment. Overall system design and testing was performed. The tests were performed to observe the output and interaction of the different power sources as some sources are added and others are removed from the grid connection. The loads on the system were also varied from no load to maximum load to observe the power source interactions.
Reference Reactor Module for the Affordable Fission Surface Power System
International Nuclear Information System (INIS)
Poston, David I.; Kapernick, Richard J.; Dixon, David D.; Amiri, Benjamin W.; Marcille, Thomas F.
Surface fission power systems on the Moon and Mars may provide the first US application of fission reactor technology in space since 1965. The requirements of many surface power applications allow the consideration of systems with much less development risk than most other space reactor applications, because of modest power (10s of kWe) and no driving need for minimal mass (allowing temperatures 2 -fueled, liquid metal-cooled fission reactor coupled to free-piston Stirling converters. The reactor shielding approach utilizes both in-situ and launched shielding to keep the dose to astronauts much lower than the natural background radiation on the lunar surface. One of the important 'affordability' attributes is that the concept has been designed to minimize both the technical and programmatic safety risk
Power Spectral Density Evaluation of Laser Milled Surfaces
Directory of Open Access Journals (Sweden)
Raoul-Amadeus Lorbeer
Full Text Available Ablating surfaces with a pulsed laser system in milling processes often leads to surface changes depending on the milling depth. Especially if a constant surface roughness and evenness is essential to the process, structural degradation may advance until the process fails. The process investigated is the generation of precise thrust by laser ablation. Here, it is essential to predict or rather control the evolution of the surfaces roughness. Laser ablative milling with a short pulse laser system in vacuum (≈1 Pa were performed over depths of several 10 µm documenting the evolution of surface roughness and unevenness with a white light interference microscope. Power spectral density analysis of the generated surface data reveals a strong influence of the crystalline structure of the solid. Furthermore, it was possible to demonstrate that this effect could be suppressed for gold.
Closed Brayton Cycle Power Conversion Unit for Fission Surface Power Phase I Final Report
Fuller, Robert L.
A Closed Brayton cycle power conversion system has been developed to support the NASA fission surface power program. The goal is to provide electricity from a small nuclear reactor heat source for surface power production for lunar and Mars environments. The selected media for a heat source is NaK 78 with water as a cooling source. The closed Brayton cycle power was selected to be 12 kWe output from the generator terminals. A heat source NaK temperature of 850 K plus or minus 25 K was selected. The cold source water was selected at 375 K plus or minus 25 K. A vacuum radiation environment of 200 K is specified for environmental operation. The major components of the system are the power converter, the power controller, and the top level data acquisition and control unit. The power converter with associated sensors resides in the vacuum radiation environment. The power controller and data acquisition system reside in an ambient laboratory environment. Signals and power are supplied across the pressure boundary electrically with hermetic connectors installed on the vacuum vessel. System level analyses were performed on working fluids, cycle design parameters, heater and cooling temperatures, and heat exchanger options that best meet the needs of the power converter specification. The goal is to provide a cost effective system that has high thermal-to-electric efficiency in a compact, lightweight package.
Inverse calculation of power density for laser surface treatment
Römer, Gerardus Richardus, Bernardus, Engelina; Meijer, J.
Laser beam surface treatment requires a well-defined temperature profile. In this paper an analytic method is presented to solve the inverse problem of heat conduction in solids, based on the 2-dimensional Fourier transform. As a result, the required power density profile of the laser beam can be
Applications of response surface methodology approach to ...
African Journals Online (AJOL)
Applications of response surface methodology approach to determine the effect of temperature, time of incubation and light conditions on germination and germ tube growth of Puccinia coronata f.sp. avenae urediosopores.
Recovery of condensate water quality in power generator's surface condenser
Kurniawan, Lilik Adib
In PT Badak NGL Plant, steam turbines are used to drive major power generators, compressors, and pumps. Steam exiting the turbines is condensed in surface condensers to be returned to boilers. Therefore, surface condenser performance and quality of condensate water are very important. One of the recent problem was caused by the leak of a surface condenser of Steam Turbine Power Generator. Thesteam turbine was overhauled, leaving the surface condenser idle and exposed to air for more than 1.5 years. Sea water ingress due to tube leaks worsens the corrosionof the condenser shell. The combination of mineral scale and corrosion product resulting high conductivity condensate at outlet condenser when we restarted up, beyond the acceptable limit. After assessing several options, chemical cleaning was the best way to overcome the problem according to condenser configuration. An 8 hour circulation of 5%wt citric acid had succeed reducing water conductivity from 50 μmhos/cm to below 5 μmhos/cm. The condensate water, then meets the required quality, i.e. pH 8.3 - 9.0; conductivity ≤ 5 μmhos/cm, therefore the power generator can be operated normally without any concern until now.
An application of the Krylov-FSP-SSA method to parameter fitting with maximum likelihood
Dinh, Khanh N.; Sidje, Roger B.
Monte Carlo methods such as the stochastic simulation algorithm (SSA) have traditionally been employed in gene regulation problems. However, there has been increasing interest to directly obtain the probability distribution of the molecules involved by solving the chemical master equation (CME). This requires addressing the curse of dimensionality that is inherent in most gene regulation problems. The finite state projection (FSP) seeks to address the challenge and there have been variants that further reduce the size of the projection or that accelerate the resulting matrix exponential. The Krylov-FSP-SSA variant has proved numerically efficient by combining, on one hand, the SSA to adaptively drive the FSP, and on the other hand, adaptive Krylov techniques to evaluate the matrix exponential. Here we apply this Krylov-FSP-SSA to a mutual inhibitory gene network synthetically engineered in Saccharomyces cerevisiae, in which bimodality arises. We show numerically that the approach can efficiently approximate the transient probability distribution, and this has important implications for parameter fitting, where the CME has to be solved for many different parameter sets. The fitting scheme amounts to an optimization problem of finding the parameter set so that the transient probability distributions fit the observations with maximum likelihood. We compare five optimization schemes for this difficult problem, thereby providing further insights into this approach of parameter estimation that is often applied to models in systems biology where there is a need to calibrate free parameters. Work supported by NSF grant DMS-1320849.
Genetic transformation of Fusarium oxysporum f.sp. gladioli with Agrobacterium to study pathogenesis in Gladiolus
Fusarium rot caused by Fusarium oxysporum f.sp. gladioli (Fog) is one of the most serious diseases of Gladiolus, both in the field and in stored bulbs. In order to study the pathogenesis of this fungus, we have transformed Fog with Agrobacterium tumefaciens binary vectors containing the hygromycin B...
Sensitivity among species of Solanaceae to AAL toxins produced by Alternaria alternata f.sp lycopersici
Mesbah, LA; van der Weerden, GM; Nijkamp, HJJ; Hille, J
The necrotrophic fungus Alternaria alternata f.sp. lycopersici produces AAL toxins that cause necrosis in tomato tissues with high specificity. Resistance or susceptibility of tomato to the fungus and insensitivity or sensitivity to AAL toxins are determined by a single locus, Asc. In order to
Evaluating fungicide sensitivity of regional Blumeria graminis f.sp. tritici populations in the United States
Blumeria graminis f.sp. tritici (Bgt), cause of wheat powdery mildew, has a high likelihood of developing fungicide resistance because of the large quantity of spores produced along with the mixed mode of reproduction. Additionally, once reduced sensitivity appears in a population it can influence n...
Materials surface damage and modification under high power plasma exposures
Garkusha, I.; Makhlaj, V.; Byrka, O.; Taran, V.; Voitsenya, V.; Malykhin, S.; Herashchenko, S.; Surovitskiy, S.; Nowakowska-Langier, K.; Sadowski, M. J.; Skladnik-Sadowska, E.; Terentyev, D.
Influence of powerful plasma impacts on several materials used for the construction of energy systems, i.e. different grades of steels as well as tungsten coatings, has been discussed. Irradiations of these materials with hydrogen and helium plasma streams have been performed in several high-current-pulse and quasi-stationary plasma accelerators which provided the variation of a power load upon the exposed surface as well as changes of the particle flux in wide ranges: the energy flux density in the range of 1-25 MJ/m2, particle flux - up to 1026-1029 ion/m2s, the plasma stream velocity - up to about 500 km/s, and the pulse duration in the range of 1-250 μs. A response of the investigated materials to extreme plasma loads, which are relevant to transient events in fusion reactors, is briefly discussed. It is demonstrated that a broad combination of mechanisms of powerful plasma interactions with various materials includes not only a surface damage caused by different erosion mechanisms, but under certain conditions it may also result in a significant improvement of material properties in the near-surface surface layer of several tens-μm in thickness. Some improvement of the structure and substructure of such a layer may be caused by the high-speed quenching, the shock wave formation and material alloying with plasma- and coating-species. The creation of unique surface structures and a considerable improvement of physical and mechanical properties of different materials can be achieved by the pulsed plasma alloying, i.e. pre-deposited coating modifications and mixing caused by the impacting plasma streams.
Lunar Surface Stirling Power Systems Using Isotope Heat Sources
Schmitz, Paul C.; Penswick, L. Barry; Shaltens, Richard K.
For many years, NASA has used the decay of plutonium-238 (Pu-238) (in the form of the General Purpose Heat Source (GPHS)) as a heat source for Radioisotope Thermoelectric Generators (RTGs), which have provided electrical power for many NASA missions. While RTGs have an impressive reliability record for the missions in which they have been used, their relatively low thermal to electric conversion efficiency and the scarcity of plutonium-238 (Pu-238) has led NASA to consider other power conversion technologies. NASA is considering returning both robotic and human missions to the lunar surface and, because of the long lunar nights (14.75 Earth days), isotope power systems are an attractive candidate to generate electrical power. NASA is currently developing the Advanced Stirling Radioisotope Generator (ASRG) as a candidate higher efficiency power system that produces greater than 160 W with two GPHS modules at the beginning of life (BOL) (32% efficiency). The ASRG uses the same Pu-238 GPHS modules, which are used in RTG, but by coupling them to a Stirling convertor provides a four-fold reduction in the number of GPHS modules. This study considers the use of americium-241 (Am-241) as a substitute for the Pu-238 in Stirling- convertor-based Radioisotope Power Systems (RPS) for power levels from tens of watts to 5 kWe. The Am-241 is used as a substitute for the Pu-238 in GPHS modules. Depending on power level, different Stirling heat input and removal systems are modeled. It was found that substituting Am-241 GPHS modules into the ASRG reduces power output by about one-fifth while maintaining approximately the same system mass. In order to obtain the nominal 160 W of electrical output of the Pu-238 ASRG requires 10 Am-241 GPHS modules. Higher power systems require changing from conductive coupling heat input and removal from the Stirling convertor to either pumped loops or heat pipes. Liquid metal pumped loops are considered as the primary heat transportation on the hot
Surface treatments for material protection in nuclear power plants
International Nuclear Information System (INIS)
De, P.K.; Gadiyar, H.S.
The paper highlights some of the surface treatment methods used in nuclear power plants to improve their performance. The corrosion resistance of zirconium alloys results from the formation of an adherent and protective film of ZrO 2 . Graphite coating of zircaloy-2 cladding minimizes the susceptibility to environmental induced cracking. Magnetite formation during the hot conditioning operation improves the corrosion resistance of carbon steel as well as controls the spread of radioactivity. It has been illustrated how the surface treatment is helpful for redistributing residual stress to facilitate conversion of tensile stress to compressive stress to mitigate failures due to stress corrosion and fatigue corrosion. Inhibitors and passivators can modify the surface conditions (in situ) of condenser tubes and cooling water systems. These aspects have been dealt in the text of the paper. (author). 8 refs., 3 figures
Power Spectral Density Specification and Analysis of Large Optical Surfaces
Sidick, Erkin
The 2-dimensional Power Spectral Density (PSD) can be used to characterize the mid- and the high-spatial frequency components of the surface height errors of an optical surface. We found it necessary to have a complete, easy-to-use approach for specifying and evaluating the PSD characteristics of large optical surfaces, an approach that allows one to specify the surface quality of a large optical surface based on simulated results using a PSD function and to evaluate the measured surface profile data of the same optic in comparison with those predicted by the simulations during the specification-derivation process. This paper provides a complete mathematical description of PSD error, and proposes a new approach in which a 2-dimentional (2D) PSD is converted into a 1-dimentional (1D) one by azimuthally averaging the 2D-PSD. The 1D-PSD calculated this way has the same unit and the same profile as the original PSD function, thus allows one to compare the two with each other directly.
Directory of Open Access Journals (Sweden)
I Ketut Suada
Full Text Available The objective of this research was to investigate suppression ability of marine biota extracts against Fusarium oxysporum f.sp. vanillae of vanilla stem rot. Samples were collected at intertidal zones and in the depth of 1-7 m from seven beaches in Bali. Screening of active compounds of biota extracts were conducted using inhibition zone of well diffusion method on Potato Dextrose Agar (PDA. The extract was tested in-vitro in PDA medium using completely randomized design with three replicates. The methanolic extract of Aglaophenia sp. was able to suppress the growth of F. oxysporum f.sp. vanillae effectively, with minimum inhibition concentration (MIC of 0.05 %. The extract inhibited colony growth diameter and total mycelial dry weight.
Hubungan Antara Aktivitas Poligalakturonase Dengan Virulensi RAS 4 Fusarium oxysporum f.sp. cubense
Directory of Open Access Journals (Sweden)
Arif Wibowo
Full Text Available One of the major constraints of banana plantation in Indonesia is the occurrence of fusarium wilt disease caused by Fusarium oxysporum f.sp. cubense. The pathogen produced series of cell wall degradation extracellular enzymes which have important roles in pathogenicity. Many studies have been conducted to know the role of degrading enzyme banana pectin is the major component of cell wall. Many pectinolytic enzymes such as polygalacturonase and others have been isolated from many fungal plant pathogens. The study was aimed to know the role of polygalacturonase towards the virulence of race 4 of F. oxysporum f.sp. cubense. The result showed that from 10 isolates of race 4 of F. oxysporum f.sp. cubense, the most virulent isolate was Lmp1 followed by Srg1, Bgl6, Mln1, Bgl3, A13, Bnt2, Gnk3, Kjg1 dan Wsb5. This was indicated by high and low percentage of wilting leaves of banana cultivar Cavendish when they were inoculated with these isolates. Incubation period varied from 3 to 6 weeks after inoculation SDS-PAGE showed that polygalacturonase, mostly PG1 and PG2, was secreted by these isolates, whereas PG3 was only found in growing cultures of Gnk3 and Wsb5 isolates. Detection of polygalacturonase activity with diffusion agar and reducing sugar methods showed that the activity of polygalacturonase secreted by F. oxysporum f.sp. cubense in the growing culture had no correlation with the virulence of the fungal pathogen. Salah satu kendala utama dalam budidaya pisang di Indonesia adalah gangguan penyakit layu fusarium yang disebabkan oleh jamur Fusarium oxysporum f.sp. cubense. Jamur patogen ini menghasilkan serangkaian enzim ekstraselular pendegradasi dinding sel yang berperan dalam patogenesis. Beberapa penelitian telah dilakukan untuk mengetahui peran enzim yang mendegradasi pektin, yang merupakan komponen penting dinding sel tanaman. Beberapa enzim pektinolitik seperti poligalakturonase dan yang lainnya telah berhasil diisolasi dari berbagai
Lessons Learned from ASCI applied to the Fusion Simulation Project (FSP)
Post, Douglass
The magnetic fusion program has proposed a 20M dollar per year project to develop a computational predictive capability for magnetic fusion experiments. The DOE NNSA launched a program in 1996, the Accelerated Strategic Computing Initiative (ASCI) to achieve the same goal for nuclear weapons to allow certification of the stockpile without testing. We present a "lessons learned" analysis of the 3B dollary 7 year ASCI program with the goal of improving the FSP to maximize the likelihood of success. The major lessons from ASCI are: 1. Build on your institution's successful history; 2.Teams are the key element; 3. Sound Software Project Management is essential: 4. Requirements, schedule and resources must be consistent; 5. Practices, not processes, are important; 6. Minimize and mitigate risks; 7. Minimize the computer science research aspect and maximize the physics elements; and 8. Verification and Validation are essential. We map this experience and recommendations into the FSP.
Polychlorinated biphenyls exposure-induced insulin resistance is mediated by lipid droplet enlargement through Fsp27.
Kim, Hye Young; Kwon, Woo Young; Kim, Yeon A; Oh, Yoo Jin; Yoo, Seung Hee; Lee, Mi Hwa; Bae, Ju Yong; Kim, Jong-Min; Yoo, Young Hyun
Although epidemiological and experimental studies demonstrated that polychlorinated biphenyls (PCBs) lead to insulin resistance, the mechanism underlying PCBs-induced insulin resistance has remained unsolved. In this study, we examined in vitro and in vivo effects of PCB-118 (dioxin-like PCB) and PCB-138 (non-dioxin-like PCB) on adipocyte differentiation, lipid droplet growth, and insulin action. 3T3-L1 adipocytes were incubated with PCB-118 or PCB-138 during adipocyte differentiation. For in vivo studies, C57BL/6 mice were administered PCB-118 or PCB-138 (37.5 mg/kg) by intraperitoneal injection and we examined adiposity and whole-body insulin action. PCB-118 and PCB-138 significantly promoted adipocyte differentiation and increased the lipid droplet (LD) size in 3T3-L1 adipocytes. In mice, both PCBs increased adipose mass and adipocyte size. Furthermore, both PCBs induced insulin resistance in vitro and in vivo. Expression of fat-specific protein 27 (Fsp27), which is localized to LD contact sites, was increased in PCB-treated 3T3-L1 adipocytes and mice. Depletion of Fsp27 by siRNA resulted in the inhibition of LD enlargement and attenuation of insulin resistance in PCB-treated 3T3-L1 adipocytes. An anti-diabetic drug, metformin, attenuated insulin resistance in PCB-treated 3T3-L1 adipocytes through the reduced expression of Fsp27 protein and LD size. This study suggests that PCB exposure-induced insulin resistance is mediated by LD enlargement through Fsp27.
Motion planning for mobile manipulators using the FSP (full space parameterization) approach
Energy Technology Data Exchange (ETDEWEB)
Pin, F.G.; Morgansen, K.A.; Tulloch, F.A.; Hacker, C.J.
The efficient utilization of the motion capabilities of mobile manipulators, i.e., manipulators mounted on mobile platforms, requires the resolution of the kinematically redundant system formed by the addition of the degrees of freedom (d.o.f.) of the platform to those of the manipulator. At the velocity level, the linearized Jacobian equation for such a redundant system represents an underspecified system of algebraic equations. In addition, constraints such as obstacle avoidance or joint limits may appear at any time during the trajectory of the system. A method, which we named the FSP (Full Space Parameterization), has recently been developed to resolve such underspecified systems with constraints that may vary in time and in number during a single trajectory. In this paper, we review the principles of the FSP and give analytical solutions for the constrained motion case, with a general optimization criterion for resolving the redundancy. We then focus on a solution to the problem introduced by the combined use of prismatic and revolute joints (a common occurrence in practical mobile manipulators) which makes the dimensions of the joint displacement vector components non-homogeneous. Successful applications to the motion planning of several large-payload mobile manipulators with up to 11 d.o.f. are discussed. Sample trajectories involving combined motions of the platform and manipulator under the time-varying occurrence of obstacle and joint limit constraints are presented to illustrate the use and efficiency of the FSP approach in complex motion planning problems.
Solid-State Thermionic Nuclear Power for Megawatt Propulsion, Planetary Surface and Commercial Power Project
George, Jeffrey
Thermionic (TI) power conversion is a promising technology first investigated for power conversion in the 1960's, and of renewed interest due to modern advances in nanotechnology, MEMS, materials and manufacturing. Benefits include high conversion efficiency (20%), static operation with no moving parts and potential for high reliability, greatly reduced plant complexity, and the potential for reduced development costs. Thermionic emission, credited to Edison in 1880, forms the basis of vacuum tubes and much of 20th century electronics. Heat can be converted into electricity when electrons emitted from a hot surface are collected across a small gap. For example, two "small" (6 kWe) Thermionic Space Reactors were flown by the USSR in 1987-88 for ocean radar reconnaissance. Higher powered Nuclear-Thermionic power systems driving Electric Propulsion (Q-thruster, VASIMR, etc.) may offer the breakthrough necessary for human Mars missions of Power generation on Earth could benefit from simpler, moe economical nuclear plants, and "topping" of more fuel and emission efficient fossil-fuel plants.
Investigation of Liquid Metal Heat Exchanger Designs for Fission Surface Power
Dyson, Rodger W.; Penswick, Barry; Robbie, Malcolm; Geng, Steven M.
Fission surface power is an option for future Moon and Mars surface missions. High power nuclear reactor heated Stirling convertors are an option to provide reliable power for long duration outpost operations. This report investigates various design approaches for the liquid metal to acceptor heat exchange and clarifies the details used in the analysis.
The Boundary/Pedestal Integrated Science Application for FSP
Energy Technology Data Exchange (ETDEWEB)
Rognlien, T. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Snyder, P. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
This Integrated Science Application (ISA) represents a combination of the former Integrated Boundary and Pedestal Science Drivers carried out over the last year as part of the Fusion Simulation Program's planning phase. Those Science Driver plans, as well as four others, can be viewed on the website (http://fspscidri.web.lehigh.edu/index.php/Main_Page). The Boundary Science Driver report is also available as LLNL document LLNL-TR-471260. The plans described in those documents assumed ample resources would be available. This document represents a plan of vital importance for developing powerful simulation tools for magnetic fusion energy devices, but is of substantially less scope than the original Science Drivers because of budget limitations and the fact that here two Science Drivers are merged owing to the close proximity of the two regions that they model: (1) the warm plasma region known as the scrapeoff layer (SOL) where magnetic field lines directly contact material structures together with the associate plasma-wall interactions and (2) the adjacent hotter plasma region know as the pedestal, which is the beginning of the confining closed magnetic field line core.
Microstructure and optical appearance of anodized friction stir processed Al - Metal oxide surface composites
DEFF Research Database (Denmark)
Gudla, Visweswara Chakravarthy; Jensen, Flemming; Bordo, Kirill
Multiple-pass friction stir processing (FSP) was employed to impregnate Ti, Y and Ce oxide powders into the surface of an Aluminium alloy. The FSP processed surface composite was subsequently anodized with an aim to develop optical effects in the anodized layer owing to the presence of incorporated...... oxide particles which will influence the scattering of light. This paper presents the investigations on relation between microstructure of the FSP zone and optical appearance of the anodized layer due to incorporation of metal oxide particles and modification of the oxide particles due to the anodizing...
A Blumeria graminis f.sp. hordei BAC library - contig building and microsynteny studies
DEFF Research Database (Denmark)
Pedersen, C.; Wu, B.; Giese, H.
A bacterial artificial chromosome (BAC) library of Blumeria graminis f.sp. hordei, containing 12,000 clones with an average insert size of 41 kb, was constructed. The library represents about three genome equivalents and BAC-end sequencing showed a high content of repetitive sequences, making...... contigs, at or close to avirulence loci, were constructed. Single nucleotide polymorphism (SNP) markers were developed from BAC-end sequences to link the contigs to the genetic maps. Two other BAC contigs were used to study microsynteny between B. graminis and two other ascomycetes, Neurospora crassa...
High Efficiency, High Temperature Foam Core Heat Exchanger for Fission Surface Power Systems, Phase II Project
National Aeronautics and Space Administration — Fission-based power systems with power levels of 30 to ≥100 kWe will be needed for planetary surface bases. Development of high temperature, high efficiency...
High Efficiency, High Temperature Foam Core Heat Exchanger for Fission Surface Power Systems, Phase I
National Aeronautics and Space Administration — Fission-based power systems are anticipated for various planetary surface human base applications with power levels of 30-100+ kWe. The development of high...
High Efficiency, High Temperature Foam Core Heat Exchanger for Fission Surface Power Systems, Phase II
National Aeronautics and Space Administration — Fission-based power systems with power levels of 30 to ≥100 kWe will be needed for planetary surface bases. Development of high temperature, high efficiency heat...
Unmanned Surface Sea Vehicle Power System Design and Modeling
National Research Council Canada - National Science Library
Pritpal, Singh
.... The power system of the USV is chosen to be a hybrid power source comprising a diesel generator and a lithium-ion battery pack Optimal sizing of the diesel generator and battery pack is important...
Heterothallism in Peronospora farinosa f.sp. chenopodii, the causal agent of downy mildew of quinoa (Chenopodium quinoa).
Danielsen, S
Heterothallism in Peronospora farinosa f.sp. chenopodii, the causal agent of downy mildew of quinoa (Chenopodium quinoa) is reported for the first time. Downy mildew is the most important disease of this crop in the Andean region. Eight single-lesion isolates from different regions in Peru and Bolivia were crossed in all possible combinations using a detached leaf assay, to determine the mating system of the downy mildew pathogen. The presence of two mating types, P1 and P2, was revealed showing that P. farinosa f.sp. chenopodii is heterothallic. It is suggested that frequent sexual reproduction is an important evolutionary force in this pathogen in South America.
[Isolation of protoplasts from vegetable tissues using extracellular lytic enzymes from fusarium oxysporum f.sp. melonis].
Alconada, T M; Martínez, M J
Fusarium oxysporum f.sp. melonis, a pathogen of melon (Cucumis melo L.), was grown in shaken cultures at 26 degrees C in a mineral salts medium containing glucose, xylan and apple pectin as carbon sources. The extracellular enzymic complex obtained from these cultures showed lytic activity on plant tissues, causing maceration of melon fruits, potato tubers and carrot roots. Protoplasts were isolated from melon fruits when the maceration was carried out under appropriate osmotic conditions. This fact suggest a possible relationship between the enzymes produced by Fusarium oxysporum f.sp. melonis and their pathogenicity on melon plants.
Resolving kinematic redundancy with constraints using the FSP (Full Space Parameterization) approach
International Nuclear Information System (INIS)
Pin, F.G.; Tulloch, F.A.
A solution method is presented for the motion planning and control of kinematically redundant serial-link manipulators in the presence of motion constraints such as joint limits or obstacles. Given a trajectory for the end-effector, the approach utilizes the recently proposed Full Space Parameterization (FSP) method to generate a parameterized expression for the entire space of solutions of the unconstrained system. At each time step, a constrained optimization technique is then used to analytically find the specific joint motion solution that satisfies the desired task objective and all the constraints active during the time step. The method is applicable to systems operating in a priori known environments or in unknown environments with sensor-based obstacle detection. The derivation of the analytical solution is first presented for a general type of kinematic constraint and is then applied to the problem of motion planning for redundant manipulators with joint limits and obstacle avoidance. Sample results using planar and 3-D manipulators with various degrees of redundancy are presented to illustrate the efficiency and wide applicability of constrained motion planning using the FSP approach
Advanced shield development for a fission surface power system for the lunar surface
International Nuclear Information System (INIS)
Craft, A.E.; Silver, I.J.; Clark, C.M.; Howe, S.D.; King, J.C.
A nuclear reactor power system such as the affordable fission surface power system enables a potential outpost on the moon. A radiation shield must be included in the reactor system to reduce the otherwise excessive dose to the astronauts and other vital system components. The radiation shield is typically the most massive component of a space reactor system, and thus must be optimized to reduce mass asmuchas possible while still providing the required protection.Various shield options for an on-lander reactor system are examined for outpost distances of 400m and 1 km from the reactor. Also investigated is the resulting mass savings from the use of a high performance cermet fuel. A thermal analysis is performed to determine the thermal behaviours of radiation shields using borated water. For an outpost located 1000m from the core, a tetramethylammonium borohydride shield is the lightest (5148.4 kg), followed by a trilayer shield (boron carbide-tungsten-borated water; 5832.3 kg), and finally a borated water shield (6020.7 kg). In all of the final design cases, the temperature of the borated water remains below 400 K.
Surface Treatment on Physical Properties and Biocompatibility of Orthodontic Power Chains
Directory of Open Access Journals (Sweden)
H. C. Cheng
Full Text Available The conventional orthodontic power chain, often composed of polymer materials, has drawbacks such as a reduction of elasticity owing to water absorption as well as surface discoloration and staining resulting from food or beverages consumed by the patient. The goal of this study was to develop a surface treatment (nanoimprinting for orthodontic power chains and to alleviate their shortcomings. A concave template (anodic alumina was manufactured by anodization process using pure aluminum substrate by employing the nanoimprinting process. Convex nanopillars were fabricated on the surface of orthodontic power chains, resulting in surface treatment. Distinct parameters of the nanoimprinting process (e.g., imprinting temperature, imprinting pressure, imprinting time, and demolding temperature were used to fabricate nanopillars on the surface of orthodontic power chains. The results of this study showed that the contact angle of the power chains became larger after surface treatment. In addition, the power chains changed from hydrophilic to hydrophobic. The power chain before surface treatment without water absorption had a water absorption rate of approximately 4%, whereas a modified chain had a water absorption rate of approximately 2%–4%. Furthermore, the color adhesion of the orthodontic power chains after surface modification was less than that before surface modification.
Surface Treatment on Physical Properties and Biocompatibility of Orthodontic Power Chains.
Cheng, H C; Chen, M S; Peng, B Y; Lin, W T; Shen, Y K; Wang, Y H
The conventional orthodontic power chain, often composed of polymer materials, has drawbacks such as a reduction of elasticity owing to water absorption as well as surface discoloration and staining resulting from food or beverages consumed by the patient. The goal of this study was to develop a surface treatment (nanoimprinting) for orthodontic power chains and to alleviate their shortcomings. A concave template (anodic alumina) was manufactured by anodization process using pure aluminum substrate by employing the nanoimprinting process. Convex nanopillars were fabricated on the surface of orthodontic power chains, resulting in surface treatment. Distinct parameters of the nanoimprinting process (e.g., imprinting temperature, imprinting pressure, imprinting time, and demolding temperature) were used to fabricate nanopillars on the surface of orthodontic power chains. The results of this study showed that the contact angle of the power chains became larger after surface treatment. In addition, the power chains changed from hydrophilic to hydrophobic. The power chain before surface treatment without water absorption had a water absorption rate of approximately 4%, whereas a modified chain had a water absorption rate of approximately 2%-4%. Furthermore, the color adhesion of the orthodontic power chains after surface modification was less than that before surface modification.
Aspects of resistance of flax and linseed (Linum usitatissimum) to Fusarium oxysporum f.sp. lini = Aspecten van de resistentie in vezel- en olievlas (Linum usitatissimum) tegen Fusarium oxysporum f.sp. lini
Kroes, I.
In the thesis aspects have been described of the flax and linseed interaction to Fusarium oxysporum f.sp. lini, the causal agent of flax wilt. Two in vitro tests were established to screen for resistance, to investigate race specificity
Technologies for protection of the Space Station power system surfaces in atomic oxygen environment
Nahra, Henry K.; Rutledge, Sharon K.
Technologies for protecting Space Station surfaces from degradation caused by atomic oxygen are discussed, stressing protection of the power system surfaces. The Space Station power system is described and research concerning the solar array surfaces and radiator surfaces is examined. The possibility of coating the solar array sufaces with a sputter deposited thin film of silicon oxide containing small concentrations of polytetrafluoroethylene is presented. Hexamethyldisiloxane coating for these surfaces is also considered. For the radiator surfaces, possible coatings include silver teflon thermal coating and zinc orthotitanate.
Linguistic Effects of Globalization: A Case Study of French for Specific Purposes (FSP) in Kenyan Vocational Schools
Mulenda, Mubalama
The study of French for Specific Purposes (FSP) is a topical subject in this era of globalization. Kenya requires people who can communicate in French in the various specialized areas. It has become crucial in Kenya to respond to the French language needs of students learning tourism and hospitality among other domains which have already shown an…
Management of Fusarium oxysporum f.sp cubense (Foc-TR4) from banana by anaerobic soil disinfestation (ASD)
Runia, W.T.
Applied Plant Research in Lelystad has, commissioned by Gert Kema, Plant Research International (PRI) and leader of the Panama Project, performed a trial to measure the efficacy of anaerobic soil disinfestation (ASD) with a 'Herbie" product against Fusarium oxysporum f.sp. cubense (Foc; TR 4),
Lunar Surface Solar Electric Power System, Phase I
National Aeronautics and Space Administration — We propose a concentrated photovoltaic electric power system for lunar operations called C-Lite Lunar. The novel technology produces a near-term solar array system...
A preliminary investigation of the Topaz II reactor as a lunar surface power supply
International Nuclear Information System (INIS)
Polansky, G.F.; Houts, M.G.
Reactor power supplies offer many attractive characteristics for lunar surface applications. The Topaz II reactor resulted from an extensive development program in the former Soviet Union. Flight quality reactor units remain from this program and are currently under evaluation in the United States. This paper examines the potential for applying the Topaz II, originally developed to provide spacecraft power, as a lunar surface power supply
A preliminary investigation of the Topaz II reactor as a lunar surface power supply
Energy Technology Data Exchange (ETDEWEB)
Polansky, G.F. [Sandia National Labs., Albuquerque, NM (United States); Houts, M.G. [Los Alamos National Lab., NM (United States)
Reactor power supplies offer many attractive characteristics for lunar surface applications. The Topaz II reactor resulted from an extensive development program in the former Soviet Union. Flight quality reactor units remain from this program and are currently under evaluation in the United States. This paper examines the potential for applying the Topaz II, originally developed to provide spacecraft power, as a lunar surface power supply.
Solid-State Thermionic Nuclear Power for Megawatt Propulsion, Planetary Surface and Commercial Power Project
National Aeronautics and Space Administration — Thermionic (TI) power conversion is a promising technology first investigated for power conversion in the 1960's, and of renewed interest due to modern...
Extracción del ADN de Fusarium Oxysporum f.sp. Dianthi
Sixta T. Martínez; Carlos Y. Soto
Se estudia la utílización de dos métodos para la extracción del ADN del Fusarium o.xy.sporum f.sp. Dianthi. En los dos métodos la pared del hongo se rompió con nitrógeno líquido, uno de ellos empleó como solución extractora bromuro de cetiltrimetil amonio (BCTA) y el otro una solución de sacarosa con altas concentraciones de protcasa y EDTA. Para la desproteinización ambos métodos utilizaron soluciones de fcnol-clorofonno y enzimas proteolítícas. El ADN obtenido se digirió con enzimas d...
A proteomic analysis of powdery mildew (Blumeria graminis f.sp. hordei) conidiospores.
Noir, Sandra; Colby, Thomas; Harzen, Anne; Schmidt, Jürgen; Panstruga, Ralph
Conidiospores are the asexual propagation units of many plant-pathogenic fungi. In this article, we report an annotated proteome map of ungerminated conidiospores of the ascomycete barley powdery mildew pathogen, Blumeria graminis f.sp. hordei. Using a combination of two-dimensional polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, we have identified the proteins in 180 spots, which probably represent at least 123 distinct fungal gene products. Most of the identified proteins have a predicted function in carbohydrate, lipid or protein metabolism, indicating that the spore is equipped for the catabolism of storage compounds as well as for protein biosynthesis and folding on germination.
Microwave power coupling in a surface wave excited plasma
Directory of Open Access Journals (Sweden)
Satyananda Kar
Full Text Available In recent decades, different types of plasma sources have been used for various types of plasma processing, such as, etching and thin film deposition. The critical parameter for effective plasma processing is high plasma density. One type of high density plasma source is Microwave sheath-Voltage combination Plasma (MVP. In the present investigation, a better design of MVP source is reported, in which over-dense plasma is generated for low input microwave powers. The results indicate that the length of plasma column increases significantly with increase in input microwave power.
A gas-cooled reactor surface power system
International Nuclear Information System (INIS)
Lipinski, R.J.; Wright, S.A.; Lenard, R.X.; Harms, G.A.
A human outpost on Mars requires plentiful power to assure survival of the astronauts. Anywhere from 50 to 500 kW of electric power (kWe) will be needed, depending on the number of astronauts, level of scientific activity, and life-cycle closure desired. This paper describes a 250-kWe power system based on a gas-cooled nuclear reactor with a recuperated closed Brayton cycle conversion system. The design draws upon the extensive data and engineering experience developed under the various high-temperature gas cooled reactor programs and under the SP-100 program. The reactor core is similar in power and size to the research reactors found on numerous university campuses. The fuel is uranium nitride clad in Nb1%Zr, which has been extensively tested under the SP-100 program. The fuel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fuel and stabilizing the geometry against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality can not occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars. copyright 1999 American Institute of Physics
A gas-cooled reactor surface power system
International Nuclear Information System (INIS)
Lipinski, Ronald J.; Wright, Steven A.; Lenard, Roger X.; Harms, Gary A.
A human outpost on Mars requires plentiful power to assure survival of the astronauts. Anywhere from 50 to 500 kW of electric power (kWe) will be needed, depending on the number of astronauts, level of scientific activity, and life-cycle closure desired. This paper describes a 250-kWe power system based on a gas-cooled nuclear reactor with a recuperated closed Brayton cycle conversion system. The design draws upon the extensive data and engineering experience developed under the various high-temperature gas cooled reactor programs and under the SP-100 program. The reactor core is similar in power and size to the research reactors found on numerous university campuses. The fuel is uranium nitride clad in Nb1%Zr, which has been extensively tested under the SP-100 program. The fuel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fuel and stabilizing the geometry against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality can not occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars
A Gas-Cooled Reactor Surface Power System
Energy Technology Data Exchange (ETDEWEB)
Harms, G.A.; Lenard, R.X.; Lipinski, R.J.; Wright, S.A.
A human outpost on Mars requires plentiful power to assure survival of the astronauts. Anywhere from 50 to 500 kW of electric power (kWe) will be needed, depending on the number of astronauts, level of scientific activity, and life- cycle closure desired. This paper describes a 250-kWe power system based on a gas-cooled nuclear reactor with a recuperated closed Brayton cycle conversion system. The design draws upon the extensive data and engineering experience developed under the various high-temperature gas cooled reactor programs and under the SP-100 program. The reactor core is similar in power and size to the research reactors found on numerous university campuses. The fuel is uranium nitide clad in Nb 1 %Zr, which has been extensively tested under the SP-I 00 program The fiel rods are arranged in a hexagonal array within a BeO block. The BeO softens the spectrum, allowing better use of the fbel and stabilizing the geometty against deformation during impact or other loadings. The system has a negative temperature feedback coefficient so that the power level will automatically follow a variable load without the need for continuous adjustment of control elements. Waste heat is removed by an air-cooled heat exchanger using cold Martian air. The amount of radioactivity in the reactor at launch is very small (less than a Curie, and about equal to a truckload of uranium ore). The system will need to be engineered so that criticality cannot occur for any launch accident. This system is also adaptable for electric propulsion or life-support during transit to and from Mars.
Fission Surface Power Systems (FSPS) Project Final Report for the Exploration Technology Development Program (ETDP): Fission Surface Power, Transition Face to Face
Palac, Donald T.
The Fission Surface Power Systems Project became part of the ETDP on October 1, 2008. Its goal was to demonstrate fission power system technology readiness in an operationally relevant environment, while providing data on fission system characteristics pertinent to the use of a fission power system on planetary surfaces. During fiscal years 08 to 10, the FSPS project activities were dominated by hardware demonstrations of component technologies, to verify their readiness for inclusion in the fission surface power system. These Pathfinders demonstrated multi-kWe Stirling power conversion operating with heat delivered via liquid metal NaK, composite Ti/H2O heat pipe radiator panel operations at 400 K input water temperature, no-moving-part electromagnetic liquid metal pump operation with NaK at flight-like temperatures, and subscale performance of an electric resistance reactor simulator capable of reproducing characteristics of a nuclear reactor for the purpose of system-level testing, and a longer list of component technologies included in the attached report. Based on the successful conclusion of Pathfinder testing, work began in 2010 on design and development of the Technology Demonstration Unit (TDU), a full-scale 1/4 power system-level non-nuclear assembly of a reactor simulator, power conversion, heat rejection, instrumentation and controls, and power management and distribution. The TDU will be developed and fabricated during fiscal years 11 and 12, culminating in initial testing with water cooling replacing the heat rejection system in 2012, and complete testing of the full TDU by the end of 2014. Due to its importance for Mars exploration, potential applicability to missions preceding Mars missions, and readiness for an early system-level demonstration, the Enabling Technology Development and Demonstration program is currently planning to continue the project as the Fission Power Systems project, including emphasis on the TDU completion and testing.
Surface temperature and distortion of optical elements exposed to high power synchrotron radiation beams
International Nuclear Information System (INIS)
Mourikis, S.; Jark, W.; Koch, E.E.; Saile, V.
Mirrors made of various materials have been investigated under surface power densities of approximately 1--2 W/mm 2 emitted by a powerful hybrid wiggler installed in the 5.3-GeV DORIS storage ring. Thermal inhomogeneities and deformations at surfaces with a height resolution of 50 nm have been determined quantitatively. The only material withstanding these power levels without a significant deformation is SiC. Conventional cooling geometries are found to be useless for a reduction of the surface distortion
Comparison of dynamic isotope power systems for distributed planetary surface applications
International Nuclear Information System (INIS)
Bents, D.J.; McKissock, B.I.; Withrow, C.A.; Hanlon, J.C.; Schmitz, P.C.
To support the Space Exploration Initiative, a study was performed to investigate and characterize dynamic isotope power system (DIPS) alternatives for the surface mission elements associated with a lunar base and subsequent manned Mars expedition
Navy Nuclear-Powered Surface Ships: Background, Issues, and Options for Congress
National Research Council Canada - National Science Library
O'Rourke, Ronald
Some Members of Congress, particularly on the House Armed Services Committee, have expressed interest in expanding the use of nuclear power to a wider array of Navy surface ships, including the Navy's planned CG(X) cruiser...
Biosonar resolving power : echo-acoustic perception of surface structures in the submillimeter range
Simon, Ralph; Knörnschild, Mirjam; Tschapka, Marco; Schneider, Annkathrin; Passauer, Nadine; Kalko, Elisabeth K V; von Helversen, Otto
The minimum distance for which two points still can be separated from each other defines the resolving power of a visual system. In an echo-acoustic context, the resolving power is usually measured as the smallest perceivable distance of two reflecting surfaces on the range axis and is found to be
The Potential Benefits of Nuclear Power on the Surface of Mars: The Robotic Exploration Perspective
Hayati, Samad A.; Balint, Tibor S.
This viewgraph presentation reviews the future planning for further exploration of the Martian Surface by robotic vehicles. Particular emphasis is given to the use of nuclear power in the planning process. Advantages of Radioisotope Power Systems and Radioisotope Heating units are reviewed.
A Pulse Power Modulator System for Commercial High Power Ion Beam Surface Treatment Applications
International Nuclear Information System (INIS)
Barrett, D.M.; Cockreham, B.D.; Dragt, A.J.; Ives, H.C.; Neau, E.L.; Reed, K.W.; White, F.E.
The Ion Beam Surface Treatment (lBESTrM) process utilizes high energy pulsed ion beams to deposit energy onto the surface of a material allowing near instantaneous melting of the surface layer. The melted layer typically re-solidifies at a very rapid rate which forms a homogeneous, fine- grained structure on the surface of the material resulting in significantly improved surface characteristics. In order to commercialize the IBESTTM process, a reliable and easy-to-operate modulator system has been developed. The QM-I modulator is a thyratron-switched five-stage magnetic pulse compression network which drives a two-stage linear induction adder. The adder provides 400 kV, 150 ns FWHM pulses at a maximum repetition rate of 10 pps for the acceleration of the ion beam. Special emphasis has been placed upon developing the modulator system to be consistent with long-life commercial service
Two dimensional simulation of high power laser-surface interaction
International Nuclear Information System (INIS)
Goldman, S.R.; Wilke, M.D.; Green, R.E.L.; Johnson, R.P.; Busch, G.E.
For laser intensities in the range of 10 8 --10 9 W/cm 2 , and pulse lengths of order 10 microsec or longer, the authors have modified the inertial confinement fusion code Lasnex to simulate gaseous and some dense material aspects of the laser-matter interaction. The unique aspect of their treatment consists of an ablation model which defines a dense material-vapor interface and then calculates the mass flow across this interface. The model treats the dense material as a rigid two-dimensional mass and heat reservoir suppressing all hydrodynamic motion in the dense material. The computer simulations and additional post-processors provide predictions for measurements including impulse given to the target, pressures at the target interface, electron temperatures and densities in the vapor-plasma plume region, and emission of radiation from the target. The authors will present an analysis of some relatively well diagnosed experiments which have been useful in developing their modeling. The simulations match experimentally obtained target impulses, pressures at the target surface inside the laser spot, and radiation emission from the target to within about 20%. Hence their simulational technique appears to form a useful basis for further investigation of laser-surface interaction in this intensity, pulse-width range. This work is useful in many technical areas such as materials processing
Analysing the influence of FSP process parameters on IGC susceptibility of AA5083 using Sugeno – Fuzzy model
Jayakarthick, C.; Povendhan, A. P.; Vaira Vignesh, R.; Padmanaban, R.
Aluminium alloy AA5083 was friction stir processed to improve the intergranular corrosion (IGC) resistance. FSP trials were performed by varying the process parameters as per Taguchi's L18 orthogonal array. IGC resistance of the friction stir processed specimens were found by immersing them in concentrated nitric acid and measuring the mass loss per unit area. Results indicate that dispersion and partial dissolution of secondary phase increased IGC resistance of the friction stir processed specimens. A Sugeno fuzzy model was developed to study the effect of FSP process parameters on the IGC susceptibility of friction stir processed specimens. Tool Rotation Speed, Tool Traverse Speed and Shoulder Diameter have a significant effect on the IGC susceptibility of the friction stir processed specimens.
The world of Mad Men: power, surface and passion.
Gerson, Mary-Joan
Mad Men is disturbing to post-millennium viewers, particularly those of a "certain" age, on three counts. First, it invokes a particular historical context of gender oppression; second it captures the prevailing post-War injunction that emotional distress is unseemly and distasteful; and third, it captures the zeitgeist's celebration of surface over substance in relationship. However, just as disturbing as these historically situated interpersonal premises is the niggling question that each relationship pairing and each episode leaves with the viewer. To wit: How much of the disconnection and the unrequited longings are reflective of a particular historical era, and to what degree do they reflect timeless aspects of character and relationship? Thus Mad Men provides an exquisitely rendered sociocultural tableau in which the viewer struggles, however articulated or not, with one of the essential knots of psychoanalytic as well as couples treatment: the complicated interpenetration of culture and character, of time and timelessness.
Development of corrosion resistant surfaces via friction stir processing for bio implant applications
Pal Singh Sodhi, Gurvinder; Singh, Harpreet
Current investigation presents the use of Friction Stir Processing (FSP) to improve the corrosion resistance of pure magnesium for biomedical applications. FSP has been used to incorporate hydroxyapetite (HAP) into Mg-surface so as to modify the chemical composition. FSP was done within a matrix of different parameters and conditions. Influence of various parameters on microstructure was also clearly observed. XRD analysis confirmed the presence of HAP, whereas SEM images revealed a uniform distribution of the imbedded phase. Microhardness and in-vitro corrosion studies were also performed. Influence of grain size on hardness was validated by Hall-Petch relationship. Corrosion behavior was explained on the basis of texture, which indicated better corrosion resistance in comparison to the pure Mg. Therefore, the study reveals that the proposed FSP methodology can be useful tool to improve mechanical and corrosion properties of pure Mg for biomedical applications.
Puccinia graminis and Blumeria graminis f.sp. tritici, Mycoses Present in Wheat and Barley in Macedonia
Karov, Ilija; Kovacevik, Biljana
During May and June of 2006 and 2007, the health of wheat and barley crops in the Republic of Macedonia was examined. Monitoring was conducted in the Skopje, Stip, Kocani, Kumanovo, Probistip, St. Nikole and Bitola areas. During monitoring the presence of Puecinia graminis and Blumeria graminis f.sp. tritiei were noted as mycoses having the greatest economic importance. Puceinia gram inis (black rust) was recorded in 'Victory' wheat in the teli...
A music quality rating test battery for cochlear implant users to compare the FSP and HDCIS strategies for music appreciation.
Looi, Valerie; Winter, Philip; Anderson, Ilona; Sucher, Catherine
The purpose of this study was to develop a music quality rating test battery (MQRTB) and pilot test it by comparing appraisal ratings from cochlear implant (CI) recipients using the fine-structure processing (FSP) and high-definition continuous interleaved sampling (HDCIS) speech processing strategies. The development of the MQRTB involved three stages: (1) Selection of test items for the MQRTB; (2) Verification of its length and complexity with normally-hearing individuals; and (3) Pilot testing with CI recipients. Part 1 involved 65 adult listeners, Part 2 involved 10 normally-hearing adults, and Part 3 involved five adult MED-EL CI recipients. The MQRTB consisted of ten songs, with ratings made on scales assessing pleasantness, naturalness, richness, fullness, sharpness, and roughness. Results of the pilot study, which compared FSP and HDCIS for music, indicated that acclimatization to a strategy had a significant effect on ratings (p genre on ratings. Overall the results suggest that the use of FSP as the default strategy for MED-EL recipients would have a positive effect on music appreciation, and that the MQRTB is an effective tool for assessing music sound quality.
Including a non-holonomic constraint in the FSP (full space parameterization) method for mobile manipulators` motion planning
Energy Technology Data Exchange (ETDEWEB)
Pin, F.G.; Hacker, C.J.; Gower, K.B.; Morgansen, K.A.
The efficient utilization of the motion capabilities of mobile manipulators, i.e.. manipulators mounted on mobile platforms, requires the resolution of the kinematically redundant system formed by the addition of the degrees of freedom (d.o.f.) of the platform to those of the manipulator. At the velocity level, the linearized Jacobian equation for such a redundant system represents an underspecified system of algebraic equations, which can be subject to a set of constraints such as obstacles in the workspace and various limits on the joint motions. A method, which we named the FSP (Full Space Parameterization), has recently been developed to resolve such underspecified systems with constraints that may vary in time and in number during a single trajectory. The application of the method to motion planning problems with obstacle and joint limit avoidance was discussed in some of our previous work. In this paper, we present the treatment in the FSP of a non-holonomic constraint on the platform motion, and give corresponding analytical solutions for resolving the redundancy with a general optimization criterion. Comparative trajectories involving a 10 d.o.f. mobile manipulator testbed moving with and without a non-holonomic constraint for the platform motion, are presented to illustrate the use and efficiency of the FSP approach in motion planning problems for highly kinematically redundant and constrained systems.
Power System Mass Analysis for Hydrogen Reduction Oxygen Production on the Lunar Surface
Colozza, Anthony J.
The production of oxygen from the lunar regolith requires both thermal and electrical power in roughly similar proportions. This unique power requirement is unlike most applications on the lunar surface. To efficiently meet these requirements, both solar PV array and solar concentrator systems were evaluated. The mass of various types of photovoltaic and concentrator based systems were calculated to determine the type of power system that provided the highest specific power. These were compared over a range of oxygen production rates. Also a hybrid type power system was also considered. This system utilized a photovoltaic array to produce the electrical power and a concentrator to provide the thermal power. For a single source system the three systems with the highest specific power were a flexible concentrator/Stirling engine system, a rigid concentrator/Stirling engine system and a tracking triple junction solar array system. These systems had specific power values of 43, 34, and 33 W/kg, respectively. The hybrid power system provided much higher specific power values then the single source systems. The best hybrid combinations were the triple junction solar array with the flexible concentrator and the rigid concentrator. These systems had a specific power of 81 and 68 W/kg, respectively.
Quinoxyfen perturbs signal transduction in barley powdery mildew (Blumeria graminis f.sp. hordei).
Wheeler, Ian E; Hollomon, Derek W; Gustafson, Gary; Mitchell, Jon C; Longhurst, Chris; Zhang, Ziguo; Gurr, Sarah J
SUMMARY Quinoxyfen is a protectant fungicide which controls powdery mildew diseases by interfering with germination and/or appressorium formation. Mutants of barley powdery mildew, Blumeria graminis f.sp. hordei, which are resistant to quinoxyfen produce fewer conidia, which germinate and form appressoria more promiscuously than do the prolific numbers of wild-type spores. This suggests that resistance bypasses host recognition signals. RT-PCR profiles of signal transduction genes, recorded during wild-type germling morphogenesis, reveals that quinoxyfen alters the accumulation of Protein Kinase C (pkc), pkc-like and catalytic subunit of Protein Kinase A (cpka) transcripts. Differential display-reverse transcription PCR identified a gene transcript in wild-type conidia that was absent, or much less abundant, in conidia from quinoxyfen-resistant mutants. This mRNA was not detectable 24 h after wild-type conidia were inoculated on to barley. It encodes a GTPase activating protein (GAP), which may interact with a small molecular weight Ras-type GTP binding protein. In the presence of quinoxyfen, the gap mRNA remains throughout germling morphogenesis. The involvement of GAP in resistance suggests that quinoxyfen inhibits mildew infection by disrupting early cell signalling events.
Proteomic analysis of developing wheat grains infected by powdery mildew (Blumeria graminis f.sp. tritici).
Li, Jie; Yang, Xi-Wen; Li, Yong-Chun; Niu, Ji-Shan; He, De-Xian
Blumeria graminis f.sp. tritici (Bgt) infection greatly interferes with the normal source-sink relationships and always causes tremendous loss of yield and quality in wheat. To better understand the impact of this pathogen on grain development, proteome characterization during grain development in susceptible wheat cultivar Xinong 979 infected by powdery mildew was investigated by 2-DE and tandem MALDI-TOF/TOF-MS. Identification of 111 differentially expressed protein spots representing 85 unique proteins and six expression patterns showed a chronological description of wheat grain formation. Comparative proteome profiles indicated that 43 protein spots displayed significant abundance change, which is mainly involved in stress/defense responses, primary metabolism, and storage protein. The down-regulation of defense response-related proteins including alpha-purothionin, lactoylglutathione lyase, and alpha-amylase inhibitor CM16 in infected grains compared to control during seed filling might be related to the susceptibility of wheat to Bgt, while the enhanced expression of beta-amylase and glyceraldehyde-3-phosphate dehydrogenase and the down-regulation of ADP glucose pyrophosphorylase in infected grains probably resulted in the negative effects on yield formation. Our data reveal the complex grain metabolism mechanisms and defense responses during compatible interactions of wheat and Bgt, and provide valuable information for further understanding of the underlying molecular processes which can possibly yield novel strategies for breeding resistant cultivars and protection strategies in the field. Copyright © 2017 Elsevier GmbH. All rights reserved.
Extracción del ADN de Fusarium Oxysporum f.sp. Dianthi
Directory of Open Access Journals (Sweden)
Sixta T. Martínez
Full Text Available Se estudia la utílización de dos métodos para la extracción del ADN del Fusarium o.xy.sporum f.sp. Dianthi. En los dos métodos la pared del hongo se rompió con nitrógeno líquido, uno de ellos empleó como solución extractora bromuro de cetiltrimetil amonio (BCTA y el otro una solución de sacarosa con altas concentraciones de protcasa y EDTA. Para la desproteinización ambos métodos utilizaron soluciones de fcnol-clorofonno y enzimas proteolítícas. El ADN obtenido se digirió con enzimas de restricción EcoRI y Hindlll. Se corroboró que cl ADN estaba libre de los contaminantes más frecuentes en hongos, como proteínas y carbohidratos por medio de ultracentrifugación en cloruro de cesio (CsCI. La extracción con BCTA presentó los mejores rendimientos.
Effects of rf power on chemical composition and surface roughness of glow discharge polymer films
Energy Technology Data Exchange (ETDEWEB)
Zhang, Ling; He, Xiaoshan; Chen, Guo; Wang, Tao; Tang, Yongjian; He, Zhibing, E-mail: email@example.com
Graphical abstract: - Highlights: • The growth mechanism of defects in GDP films was studied upon plasma diagnosis. • Increasing rf power enhanced the etching effects of smaller-mass species. • The "void" defect was caused by high energy hydrocarbons bombardment on the surface. • The surface roughness was only 12.76 nm, and no "void" defect was observed at 30 W. - Abstract: The glow discharge polymer (GDP) films for laser fusion targets were successfully fabricated by plasma enhanced chemical vapor deposition (PECVD) at different radio frequency (rf) powers. The films were deposited using trans-2-butene (T{sub 2}B) mixed with hydrogen as gas sources. The composition and state of plasma were diagnosed by quadrupole mass spectrometer (QMS) and Langmuir probe during the deposition process. The composition, surface morphology and roughness were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and white-light interferometer (WLI), respectively. Based on these observation and analyses, the growth mechanism of defects in GDP films were studied. The results show that, at low rf power, there is a larger probability for secondary polymerization and formation of multi-carbon C-H species in the plasma. In this case, the surface of GDP film turns to be cauliflower-like. With the increase of rf power, the degree of ionization is high, the relative concentration of smaller-mass hydrocarbon species increases, while the relative concentration of larger-mass hydrocarbon species decreases. At higher rf power, the energy of smaller-mass species are high and the etching effects are strong correspondingly. The GDP film's surface roughness shows a trend of decrease firstly and then increase with the increasing rf power. At rf power of 30 W, the surface root-mean-square roughness (Rq) drops to the lowest value of 12.8 nm, and no "void" defect was observed.
Closed surfaces of constant visual acuity in symmetric dioptric power space.
Rubin, A; Harris, W F
This paper demonstrates a multivariate approach to understanding the complicated relations of visual acuity to refractive state or ametropia. Other approaches, as previously used, included graphical representations of lines or profiles of iso-oxyopia (Peters, 1961). But one limitation of Peters' method is that cylinder axis was ignored. However, here the relationship between visual acuity and refractive power will be represented by estimated closed surfaces of constant visual acuity in symmetric dioptric power space. At or near the common center (of several closed surfaces, for example) is the refractive compensation. Coming outwards from such a center, the visual acuity drops in all directions in the space. The primary purpose of this paper was to present estimated closed surfaces of constant visual acuity for several eyes. Various procedures were performed on several subjects including measurement of iris aperture diameter, subjective refraction, and autorefraction. Thereafter, an automated phoropter and either Jackson cross-cylinders or spheres were used to influence dioptric blur or defocus in the subjects. The visual stimulus was a computer-generated nondirectional or meridionally independent letter O. Ovoidal surfaces fit the measurements obtained (with Jackson cross-cylinders and spheres) better than ellipsoidal surfaces. The cross-section, in symmetric dioptric power space, at powers with the same nearest equivalent sphere as the refractive compensation is elliptical in many cases and reflects a dependence of visual acuity on cylinder axis. The surfaces differ when powers are changed so that one is moving away from (decompensation surfaces) or toward (accompensation surfaces) the refractive compensation. The multivariate and graphical methods used in this paper probably have implications for the direction of future research in a number of areas involving measures of vision function such as autorefraction, retinoscopy, subjective refraction, and visual
Experimental study on surface properties of the PMMA used in high power spark gaps
Han, Ruoyu; Wu, Jiawei; Ding, Weidong; Liu, Yunfei; Gou, Yang
This paper studies the surface properties of the Polymethylmethacrylate (PMMA) insulator samples used in high power spark gaps. Experiments on surface morphology, surface profile, surface chemical composition and surface leakage current were performed. Metal particles ejected in tangent direction of discharge spots were researched on the sample surface. Three kinds of distinct bands were found on the surface after 1500 shots: colorless and transparent sinking band, black band, and grey powdered coating band. The thickness of the coating band was tens of microns and the maximum radial erosion rate was about 10 μm/C. Surface content analysis indicated that the powdered coating was a mixture of decomposed insulator material and electrode material oxides. In addition, leakage current significantly depended on water content in the chamber and presented an U-shape curve distribution along the insulator surface, in keeping with the amount of powdered coating due to shock waves. Possible reasons of the surface property changes were discussed. Electroconductive oxides of low valence states of Cu and W produced by the reactions between electrode materials and arc plasmas were considered to be the cause of dielectric performance degradation.
Radioisotope Stirling Engine Powered Airship for Atmospheric and Surface Exploration of Titan
Colozza, Anthony J.; Cataldo, Robert L.
The feasibility of an advanced Stirling radioisotope generator (ASRG) powered airship for the near surface exploration of Titan was evaluated. The analysis did not consider the complete mission only the operation of the airship within the atmosphere of Titan. The baseline airship utilized two ASRG systems with a total of four general-purpose heat source (GPHS) blocks. Hydrogen gas was used to provide lift. The ASRG systems, airship electronics and controls and the science payload were contained in a payload enclosure. This enclosure was separated into two sections, one for the ASRG systems and the other for the electronics and payload. Each section operated at atmospheric pressure but at different temperatures. The propulsion system consisted of an electric motor driving a propeller. An analysis was set up to size the airship that could operate near the surface of Titan based on the available power from the ASRGs. The atmospheric conditions on Titan were modeled and used in the analysis. The analysis was an iterative process between sizing the airship to carry a specified payload and the power required to operate the electronics, payload and cooling system as well as provide power to the propulsion system to overcome the drag on the airship. A baseline configuration was determined that could meet the power requirements and operate near the Titan surface. From this baseline design additional trades were made to see how other factors affected the design such as the flight altitude and payload mass and volume.
Effect of Vibration Training on Anaerobic Power and Quardroceps Surface EMG in Long Jumpers
Liu, Bin; Luo, Jiong
Objective: To explore the anaerobic power and surface EMG (sEMG) of quardrocep muscle in lower extremities after single vibration training intervention. Methods: 8 excellent male long jumpers voluntarily participated in this study. Four intervention modes were devised, including high frequency high amplitude (HFHA,30Hz,6mm), low frequency low…
Thermal simulation of surface micromachined polysilicon hot plates of low power consumption
Dumitrescu, Marius; Cobianu, Cornel; Lungu, Dan; Pascu, Adrian; Kolev, Spas; van den Berg, Albert
A simple, IC compatible, surface micromachined polysilicon membrane was technologically designed and thermally simulated by 3D finite element 'COSMOS' program in order to investigate its capability to work as a micro hot plate for a gas sensing test structure of low power consumption. For an
Controle de Rhizoctonia solani e Fusarium oxysporum f.sp. phaseoli por biopreparados de isolados de Trichoderma spp.
Directory of Open Access Journals (Sweden)
Pedro Paulo Dias
Full Text Available Os experimentos objetivaram avaliar em condições de casa de vegetação o biocontrole dos fitopatógenos Rhizoctonia solani (RS e Fusarium oxysporum f.sp. phaseoli (FOP em alface (Lactuca sativa L. cultivar Regina, e feijão-vagem (Phaseolus vulgaris L. cultivar Alessa, respectivamente, utilizando como agentes antagonistas, 10 isolados de Trichoderma spp. selecionados em testes in vitro. Foram feitos biopreparados à base de arroz previamente colonizado por isolados de Trichoderma spp. e posteriormente triturados. Para a realização dos testes, os biopreparados foram inoculados previamente na proporção de 10(9 conídios.mL-1, em substrato comercial para produção de mudas. Após sete dias, os patógenos foram introduzidos separadamente em duas concentrações distintas: R. solani na proporção de 144 mg de meio de arroz por kg de substrato e F. oxysporum f.sp. phaseoli inoculado na forma de suspensão contendo 4,75 x 10(6 conídios.mL-1. Avaliou-se a influência dos biopreparados na % de damping-off de pós-emergência em plantas de alface e a severidade de murcha em plantas de feijão-vagem. O biopreparado referente ao isolado T-03 foi o mais eficiente no controle de R. solani em plantas de alface cultivar Regina, por ter reduzido a incidência de damping-off de pós-emergência nessa cultura. Por outro lado, nenhum dos biopreparados apresentou efeito antagonista satisfatório à F. oxysporum f.sp. phaseoli em plantas de feijão-vagem.
Influence of climatic factors and the ground surface on the required noise abatement from power equipment
Tupov, V. B.; Taratorin, A. A.
The influence of climatic factors and the ground surface on the required noise abatement from the power equipment is analyzed. It is shown that annual oscillations of temperature and humidity lead to substantial variations in the levels of the sound and the sound pressure from the same source in the design point, while the ground effect surface can in some cases cause an increase in the sound pressure levels in the design point, and in other cases—their decrease. When developing the measures on sound suppression of the power equipment, it is recommended to take into account the influence of climatic factors depending on annual variations in temperature and humidity for this terrain as well as on the category of the ground surface.
Biosonar resolving power: Echo-acoustic perception of surface structures in the submillimeter range
Directory of Open Access Journals (Sweden)
Ralph eSimon
Full Text Available The minimum distance for which two points still can be separated from each other defines the resolving power of a visual system. In an echo-acoustic context, the resolving power is usually measured as the smallest perceivable distance of two reflecting surfaces on the range axis and is found to be around half a millimetre for bats employing frequency modulated echolocation calls. Only few studies measured such thresholds with physical objects, most often bats were trained on virtual echoes i.e. echoes generated and played back by a computer; moreover, bats were sitting while they received the stimuli. In these studies differences in structure depth between 200 µm and 340 µm were found. However, these low thresholds were never verified for free-flying bats and real physical objects. Here, we show behavioural evidence that the echo-acoustic resolving power for surface structures in fact can be as low as measured for computer generated echoes and even lower, sometimes below 100 µm. We found this exceptional fine discrimination ability only when one of the targets showed spectral interferences in the frequency range of the bats' echolocation call while the other target did not. This result indicates that surface structure is likely to be perceived as a spectral quality rather than being perceived strictly in the time domain. Further, it points out that sonar resolving power directly depends on the highest frequency/shortest wavelength of the signal employed.
Temperature evaluation of dental implant surface irradiated with high-power diode laser.
Rios, F G; Viana, E R; Ribeiro, G M; González, J C; Abelenda, A; Peruzzo, D C
The prevalence of peri-implantitis and the absence of a standard approach for decontamination of the dental implant surface have led to searches for effective therapies. Since the source of diode lasers is portable, has reduced cost, and does not cause damage to the titanium surface of the implant, high-power diode lasers have been used for this purpose. The effect of laser irradiation on the implants is the elevation of the temperature surface. If this elevation exceeds 47 °C, the bone tissue is irreversibly damaged, so for a safety therapy, the laser parameters should be controlled. In this study, a diode laser of GaAsAl was used to irradiate titanium dental implants, for powers 1.32 to 2.64 W (real) or 2.00 to 4.00 W (nominal), in continuous/pulsed mode DC/AC, with exposure time of 5/10 s, with/without air flow for cooling. The elevation of the temperature was monitored in real time in two positions: cervical and apical. The best results for decontamination using a 968-nm diode laser were obtained for a power of 1.65 and 1.98 W (real) for 10 s, in DC or AC mode, with an air flow of 2.5 l/min. In our perspective in this article, we determine a suggested approach for decontamination of the dental implant surface using a 968-nm diode laser.
Feasibility of Ground Testing a Moon and Mars Surface Power Reactor in EBR-II
International Nuclear Information System (INIS)
Sheryl Morton; Carl Baily; Tom Hill; Jim Werner
Ground testing of a surface fission power system would be necessary to verify the design and validate reactor performance to support safe and sustained human exploration of the Moon and Mars. The Idaho National Laboratory (INL) has several facilities that could be adapted to support a ground test. This paper focuses on the feasibility of ground testing at the Experimental Breeder Reactor II (EBR-II) facility and using other INL existing infrastructure to support such a test. This brief study concludes that the INL EBR-II facility and supporting infrastructure are a viable option for ground testing the surface power system. It provides features and attributes that offer advantages to locating and performing ground testing at this site, and it could support the National Aeronautics and Space Administration schedules for human exploration of the Moon. This study used the initial concept examined by the U.S. Department of Energy Inter-laboratory Design and Analysis Support Team for surface power, a low-temperature, liquid-metal, three-loop Brayton power system. With some facility modification, the EBR-II can safely house a test chamber and perform long-term testing of the space reactor power system. The INL infrastructure is available to receive and provide bonded storage for special nuclear materials. Facilities adjacent to EBR-II can provide the clean room environment needed to assemble and store the test article assembly, disassemble the power system at the conclusion of testing, and perform post test examination. Capability for waste disposal is also available at the INL
Feasibility of Ground Testing a Moon and Mars Surface Power Reactor in EBR-II
Energy Technology Data Exchange (ETDEWEB)
Sheryl Morton; Carl Baily; Tom Hill; Jim Werner
Ground testing of a surface fission power system would be necessary to verify the design and validate reactor performance to support safe and sustained human exploration of the Moon and Mars. The Idaho National Laboratory (INL) has several facilities that could be adapted to support a ground test. This paper focuses on the feasibility of ground testing at the Experimental Breeder Reactor II (EBR-II) facility and using other INL existing infrastructure to support such a test. This brief study concludes that the INL EBR-II facility and supporting infrastructure are a viable option for ground testing the surface power system. It provides features and attributes that offer advantages to locating and performing ground testing at this site, and it could support the National Aeronautics and Space Administration schedules for human exploration of the Moon. This study used the initial concept examined by the U.S. Department of Energy Inter-laboratory Design and Analysis Support Team for surface power, a lowtemperature, liquid-metal, three-loop Brayton power system. With some facility modification, the EBR-II can safely house a test chamber and perform long-term testing of the space reactor power system. The INL infrastructure is available to receive and provide bonded storage for special nuclear materials. Facilities adjacent to EBR-II can provide the clean room environment needed to assemble and store the test article assembly, disassemble the power system at the conclusion of testing, and perform posttest examination. Capability for waste disposal is also available at the INL.
Feasibility of Ground Testing a Moon and Mars Surface Power Reactor in EBR-II
International Nuclear Information System (INIS)
Morton, Sheryl L.; Baily, Carl E.; Hill, Thomas J.; Werner, James E.
Ground testing of a surface fission power system would be necessary to verify the design and validate reactor performance to support safe and sustained human exploration of the Moon and Mars. The Idaho National Laboratory (INL) has several facilities that could be adapted to support a ground test. This paper focuses on the feasibility of ground testing at the Experimental Breeder Reactor II (EBR-II) facility and using other INL existing infrastructure to support such a test. This brief study concludes that the INL EBR-II facility and supporting infrastructure are a viable option for ground testing the surface power system. It provides features and attributes that offer advantages to locating and performing ground testing at this site, and it could support the National Aeronautics and Space Administration schedules for human exploration of the Moon. This study used the initial concept examined by the U.S. Department of Energy Inter-laboratory Design and Analysis Support Team for surface power, a low-temperature, liquid-metal, three-loop Brayton power system. With some facility modification, the EBR-II can safely house a test chamber and perform long-term testing of the space reactor power system. The INL infrastructure is available to receive and provide bonded storage for special nuclear materials. Facilities adjacent to EBR-II can provide the clean room environment needed to assemble and store the test article assembly, disassemble the power system at the conclusion of testing, and perform posttest examination. Capability for waste disposal is also available at the INL
Expression of resistance to Blumeria graminis f.sp. tritici in 'Chinese Spring' wheat addition lines containing chromosomes from Hordeum vulgare and H. chilense.
Rubiales, D; Carver, T W; Martín, A
Blumeria graminis f.sp. tritici (syn. Erysiphe graminis f.sp. tritici) causes an important disease of wheat (powdery mildew) to which Hordeum vulgare and H. chilense are resistant. The study of chromosomal addition lines of H. vulgare and H. chilense in wheat showed that they possessed resistance to wheat powdery mildew. This was expressed as a reduction of disease severity but it was not associated with increased macroscopically visible necrosis. The resistance is of broad genetic basis, conferred by gene(s) present on different chromosomes of both H. vulgare and H. chilense. The feasibility of transferring this resistance to wheat is discussed.
Theoretical and experimental approach to the texturization process of bioreactive surfaces by high-power laser
Conde, J. C.; Riveiro, A.; Comesana, R.; Pou, J.
The properties of orthopaedic/dental implants can be tuned through the laser surface modifications that take place during a laser ablation process. Processing assisted by a laser is adequate to produce macro- and micro-structures on metallic alloys and polymer surfaces in order to improve their biological response. The evaluation of the minimum energy density that causes an optimum ablation process on different kinds of surfaces was theoretically established by numerical simulation of the thermal process and some experiments have been systematically carried out to produce a periodic pattern in the surface. The selection of the laser power has been predicted from numerical analysis solving of the heat conduction differential equation using commercial software, ANSYS (11.0). This analysis has allowed us to predict the extent and the depth of the holes. The theoretical results agree with the experimental measurements that were carried out by profilometry.
In silico analysis of the core signaling proteome from the barley powdery mildew pathogen (Blumeria graminis f.sp. hordei).
Kusch, Stefan; Ahmadinejad, Nahal; Panstruga, Ralph; Kuhn, Hannah
Compared to other ascomycetes, the barley powdery mildew pathogen Blumeria graminis f.sp. hordei (Bgh) has a large genome (ca. 120 Mbp) that harbors a relatively small number of protein-coding genes (ca. 6500). This genomic assemblage is thought to be the result of numerous gene losses, which likely represent an evolutionary adaptation to a parasitic lifestyle in close association with its host plant, barley (Hordeum vulgare). Approximately 8% of the Bgh genes are predicted to encode virulence effectors that are secreted into host tissue and/or cells to promote pathogenesis; the remaining proteome is largely uncharacterized at present. We provide a comparative analysis of the conceptual Bgh proteome, with an emphasis on proteins with known roles in fungal development and pathogenicity, for example heterotrimeric G proteins and G protein coupled receptors; components of calcium and cAMP signaling; small monomeric GTPases; mitogen-activated protein cascades and transcription factors. The predicted Bgh proteome lacks a number of proteins that are otherwise conserved in filamentous fungi, including two proteins that are required for the formation of anastomoses (somatic hyphal connections). By contrast, apart from minor modifications, all major canonical signaling pathways are retained in Bgh. A family of kinases that preferentially occur in pathogenic species of the fungal clade Leotiomyceta is unusually expanded in Bgh and its close relative, Blumeria graminis f.sp. tritici. Our analysis reveals characteristic features of the proteome of a fungal phytopathogen that occupies an extreme habitat: the living plant cell.
Radiation characteristics of input power from surface wave sustained plasma antenna
International Nuclear Information System (INIS)
Naito, T.; Yamaura, S.; Fukuma, Y.; Sakai, O.
This paper reports radiation characteristics of input power from a surface wave sustained plasma antenna investigated theoretically and experimentally, especially focusing on the power consumption balance between the plasma generation and the radiation. The plasma antenna is a dielectric tube filled with argon and small amount of mercury, and the structure is a basic quarter wavelength monopole antenna at 2.45 GHz. Microwave power at 2.45 GHz is supplied to the plasma antenna. The input power is partially consumed to sustain the plasma, and the remaining part is radiated as a signal. The relationship between the antenna gain and the input power is obtained by an analytical derivation and numerical simulations. As a result, the antenna gain is kept at low values, and most of the input power is consumed to increase the plasma volume until the tube is filled with the plasma whose electron density is higher than the critical electron density required for sustaining the surface wave. On the other hand, the input power is consumed to increase the electron density after the tube is fully filled with the plasma, and the antenna gain increases with increasing the electron density. The dependence of the antenna gain on the electron density is the same as that of a plasma antenna sustained by a DC glow discharge. These results are confirmed by experimental results of the antenna gain and radiation patterns. The antenna gain of the plasma is a few dB smaller than that of the identical metal antenna. The antenna gain of the plasma antenna is sufficient for the wireless communication, although it is difficult to substitute the plasma antenna for metal antennas completely. The plasma antenna is suitable for applications having high affinity with the plasma characteristics such as low interference and dynamic controllability.
Thermodynamic analysis and optimization of a Stirling cycle for lunar surface nuclear power system
International Nuclear Information System (INIS)
Fan, Senqing; Li, Minghai; Li, Sizhong; Zhou, Tong; Hu, Yupeng; Wu, Song
Highlights: • Lunar surface nuclear power system with Stirling cycle for energy conversion. • A model with finite time thermodynamics to describe the system thermal efficiency. • Higher hot side temperature not exceeds 1050 K increased thermal efficiency. • Higher cold side temperature decreased thermal efficiency but improved heat rejection. • Higher convection heat transfer coefficient improved the thermal efficiency. - Abstract: A model for the description of the thermal efficiency of a lunar surface nuclear reactor power system with eight free piston Stirling engines to generate nominal electrical power of 100 kWe was developed. The heat loss of the hot heat pipes, finite rate heat transfer, regenerative heat loss, finite regeneration process time and conductive thermal bridging losses were considered. The results showed that the thermal efficiency increased and then decreased with the hot side temperature increase. The highest thermal efficiency was about 0.29 under the condition of the effectiveness of the regenerator being 0.9 and compression ratio being 2. Higher cold side temperature had bad effect on the thermal efficiency but could reduce the size of the heat rejection system. When the cold side temperature was designed as 500 K, the lowest power system mass of 6.6 ton could be obtained. Enhanced heat transfer of the heat exchangers would increase the thermal efficiency but higher values of the nominal convection heat transfer coefficient of the heat exchangers would lead to a negligible thermal efficiency increase. The results obtained here may provide a new ideal to design lunar surface nuclear powered Stirling cycle.
Development of surface composite based on Mg–Al–Ni system on AZ31 magnesium alloy and evaluation of formation mechanism
Energy Technology Data Exchange (ETDEWEB)
Abdollahi, S.H.; Karimzadeh, F., E-mail: email@example.com; Enayati, M.H.
Highlights: • This research showed that by applying friction stir processing (FSP) in-situ surface composite based on Mg–Al/Ni alloying systems is produced on AZ31 plate under different FSP passes. • Thermodynamic and kinetic study of interfacial solid state reactions confirmed phase formation during different FSP passes. • Moreover, the effective Gibbs free energy of formation graphs for the compounds were plotted at 711 K. • Based on kinetic standpoint, schematic diagram of Mg–Ni intermetallic compounds during difference FSP passes is plotted. • Due to presence of intermetallic phases the mean hardness of the stir zone reached about 106 Hv, which is about two times higher than the base metal. - Abstract: The in-situ synthesis of Mg–Al–Ni composite on the surface of AZ31 plate by friction stir processing (FSP), has been investigated in this article. The unprocessed AZ31 plate consisted of grains of 25 μm size. By increasing the number of FSP passes from one to five, the grain size of the AZ31 plate decreased to 7.5 and 3 μm, respectively. A uniform distribution of the reinforcements was also obtained by increasing the number of FSP passes. Based on the results of X-ray diffraction (XRD) and Energy dispersive spectrometry (EDS) analyses, Mg{sub 2}Ni and Al{sub 3}Ni{sub 2} intermetallic compounds are in-situ formed by a single-pass FSP of the composite specimens. By increasing the number of FSP passes, the amounts of Mg{sub 2}Ni and Al{sub 3}Ni{sub 2} compounds are dramatically reduced and AlNi and MgNi{sub 2} intermetallic compounds take their place. Thermodynamic and kinetic of interfacial solid state reactions were studied to determine the reactive mechanisms and phase evolutions during different passes of FSP. The maximum amount of hardness (∼106 Hv), was obtained for the composite sample after five passes of FSP.
Performance Evaluation Criterion at Equal Pumping Power for Enhanced Performance Heat Transfer Surfaces
Directory of Open Access Journals (Sweden)
Rajendra Karwa
Full Text Available The existing equations for the thermal performance evaluation, at equal pumping power for the artificially roughened and smooth surfaced multitube and rectangular duct heat exchangers, have been critically reviewed because the literature survey indicates that a large number of researchers have not interpreted these equations correctly. Three of the most widely used equations have been restated with clearly defined constraints and conditions for their application. Two new equations have been developed for the design constraints not covered earlier.
Power Prediction Model for Turning EN-31 Steel Using Response Surface Methodology
Directory of Open Access Journals (Sweden)
M. Hameedullah
Full Text Available Power consumption in turning EN-31 steel (a material that is most extensively used in automotive industry with tungstencarbide tool under different cutting conditions was experimentally investigated. The experimental runs were planned accordingto 24+8 added centre point factorial design of experiments, replicated thrice. The data collected was statisticallyanalyzed using Analysis of Variance technique and first order and second order power consumption prediction models weredeveloped by using response surface methodology (RSM. It is concluded that second-order model is more accurate than thefirst-order model and fit well with the experimental data. The model can be used in the automotive industries for decidingthe cutting parameters for minimum power consumption and hence maximum productivity
High Temperature Stability of Dissimilar Metal Joints in Fission Surface Power Systems
Locci, Ivan E.; Nesbitt, James A.; Ritzert, Frank J.; Bowman, Cheryl L.
Future generations of power systems for spacecraft and lunar surface systems will likely require a strong dependence on nuclear power. The design of a space nuclear power plant involves integrating together major subsystems with varying materia1 requirements. Refractory alloys are repeatedly considered for major structural components in space power reactor designs because refractory alloys retain their strength at higher temperatures than other classes of metals. The relatively higher mass and lower ductility of the refractory alloys make them less attractive for lower temperature subsystems in the power plant such as the power conversion system. The power conversion system would consist more likely of intermediate temperature Ni-based superalloys. One of many unanswered questions about the use of refractory alloys in a space power plant is how to transition from the use of the structural refractory alloy to more traditional structural alloys. Because deleterious phases can form when complex alloys are joined and operated at elevated temperatures, dissimilar material diffusion analyses of refractory alloys and superalloys are needed to inform designers about options of joint temperature and operational lifetime. Combinations of four superalloys and six refractory alloys were bonded and annealed at 1150 K and 1300 K to examine diffusional interactions in this study. Joints formed through hot pressing and hot isostatic pressing were compared. Results on newer alloys compared favorably to historical data. Diffusional stability is promising for some combinations of Mo-Re alloys and superalloys at 1150 K, but it appears that lower joint temperatures would be required for other refractory alloy couples.
Suppression of wheat TaCDK8/TaWIN1 interaction negatively affects germination of Blumeria graminis f.sp. tritici by interfering with very-long-chain aldehyde biosynthesis.
Kong, Lingyao; Chang, Cheng
Wheat TaCDK8 interacts with TaWIN1 to regulate very-long-chain aldehyde biosynthesis required for efficient germination of Blumeria graminis f.sp. tritici. Powdery mildew caused by Blumeria graminis f.sp. tritici (Bgt) is a devastating disease of common wheat (Triticum aestivum L.). Bgt infection initiates with its conidia germination on the aerial surface of wheat. In this study, we isolated the cyclin-dependent kinase 8 (TaCDK8) from wheat cultivar Jing411 and found that silencing of TaCDK8 impeded Bgt germination. The biochemical and molecular-biological assays revealed that TaCDK8 interacts with and phosphorylates the wheat transcription factor wax inducer 1 (TaWIN1) to stimulate the TaWIN1-dependent transcription. Bgt conidia on the leaves of TaWIN1-silenced plants also showed reduced germination. Gas chromatographic analysis revealed that knockdown of TaCDK8 or TaWIN1 resulted in decreases of wax components and cutin monomers in wheat leaves. Moreover, Bgt germination on leaves of TaCDK8 or TaWIN1 silenced plants could be fully restored by application of wild-type cuticular wax. In vitro studies demonstrated that very-long-chain aldehydes absent from the cuticular wax of the TaCDK8 or TaWIN1 silenced plants were capable of chemically stimulating Bgt germination. These results implicated that the suppression of TaCDK8/TaWIN1 interaction negatively affects Bgt germination by interfering with very-long-chain aldehyde biosynthesis required for efficient fungal germination.
Method for controlling a coolant liquid surface of cooling system instruments in an atomic power plant
International Nuclear Information System (INIS)
Monta, Kazuo.
Object: To prevent coolant inventory within a cooling system loop in an atomic power plant from being varied depending on loads thereby relieving restriction of varied speed of coolant flow rate to lowering of a liquid surface due to short in coolant. Structure: Instruments such as a superheater, an evaporator, and the like, which constitute a cooling system loop in an atomic power plant, have a plurality of free liquid surface of coolant. Portions whose liquid surface is controlled and portions whose liquid surface is varied are adjusted in cross-sectional area so that the sum total of variation in coolant inventory in an instrument such as a superheater provided with an annulus portion in the center thereof and an inner cylindrical portion and a down-comer in the side thereof comes equal to that of variation in coolant inventory in an instrument such as an evaporator similar to the superheater. which is provided with an overflow pipe in its inner cylindrical portion or down-comer, thereby minimizing variation in coolant inventory of the entire coolant due to loads thus minimizing variation in varied speed of the coolant. (Kamimura, M.)
Dry Etch Black Silicon with Low Surface Damage: Effect of Low Capacitively Coupled Plasma Power
DEFF Research Database (Denmark)
Iandolo, Beniamino; Plakhotnyuk, Maksym; Gaudig, Maria
Black silicon fabricated by reactive ion etch (RIE) is promising for integration into silicon solar cells thanks to its excellent light trapping ability. However, intensive ion bombardment during the RIE induces surface damage, which results in enhanced surface recombination velocity. Here, we pr...... carrier lifetime thanks to reduced ion energy. Surface passivation using atomic layer deposition of Al2O3 improves the effective lifetime to 7.5 ms and 0.8 ms for black silicon n- and p-type wafers, respectively.......Black silicon fabricated by reactive ion etch (RIE) is promising for integration into silicon solar cells thanks to its excellent light trapping ability. However, intensive ion bombardment during the RIE induces surface damage, which results in enhanced surface recombination velocity. Here, we...... present a RIE optimization leading to reduced surface damage while retaining excellent light trapping and low reflectivity. In particular, we demonstrate that the reduction of the capacitively coupled power during reactive ion etching preserves a reflectance below 1% and improves the effective minority...
A comparison of two systems for lunar surface remote and mobile power applications
International Nuclear Information System (INIS)
Determan, W.R.; Otting, W.D.; Hunt, M.E.
The free piston Stirling engine (FPSE) is now being developed by Mechanical Technology Incorporated (MTI) and NASA-LeRC for space power applications. Some conceptualizations of an isotope powered FPSE have been proposed. The performance characteristics of the proposed 2.5-kWe Stirling Isotope Power (STIP) system were developed for lunar surface remote and mobile applications. The Stirling system configuration uses a nonredundant power conversion system coupled to an annular heat source assembly (HSA) using an array of sodium heat pipes which transfer energy from the annular general-purpose heat source (GPHS) stack within the HSA to the Stirling heater head. The Stirling engine uses a dual-opposed piston design with heater head coupling. The engine coolers are connected to a single-pumped coolant loop, which rejects the cycle's waste heat to a radiator. Quantitative information, such as mass, area, and efficiency, are reported for the system. The results of a qualitative evaluation of the proposed STIP system against the desirable attributes of a lunar-based isotope power system are presented. Alternate configurations are also presented
Mechanisms involved in control of ¤Blumeria graminis¤ f.sp. ¤hordei¤ in barley treated with mycelial extracts from cultured fungi
DEFF Research Database (Denmark)
Haugaard, H.; Collinge, D.B.; Lyngkjær, Michael Foged
Treatment with mycelial extracts, prepared from liquid cultures of Bipolaris oryzae , Pythium ultimum and Rhizopus stolonifer , protected barley (Hordeum vulgare ) against powdery mildew disease caused by the fungus Blumeria graminis f.sp. hordei . The mechanisms of this protection were studied u...
Genetic variation in Danish populations of Erysiphe graminis f.sp. hordei: estimation of gene diversity and effective population size using RFLP data
DEFF Research Database (Denmark)
Damgaard, C.; Giese, Nanna Henriette
Genetic variation of the barley powdery mildew fungus (Erysiphe graminis f.sp. hordei) was estimated in three Danish local populations. Genetic variation was estimated from the variation amongst clones of Egh, and was therefore an estimate of the maximum genetic variation in the local populations...
Fabrication of Surface Level Cu/Si Cp Nano composites by Friction Stir Processing Route
International Nuclear Information System (INIS)
Srinivasan, R. C.; Karunanithi, M.
Friction stir processing (FSP) technique has been successfully employed as low energy consumption route to prepare copper based surface level nano composites reinforced with nano sized silicon carbide particles (Si Cp). The effect of FSP parameters such as tool rotational speed, processing speed, and tool tilt angle on microstructure and microhardness was investigated. Single pass FSP was performed based on Box-Behnken design at three factors in three levels. A cluster of blind holes 2 mm in diameter and 3 mm in depth was used as particulate deposition technique in order to reduce the agglomeration problem during composite fabrication. K-type thermocouples were used to measure temperature histories during FSP. The results suggest that the heat generation during FSP plays a significant role in deciding the microstructure and microhardness of the surface composites. Microstructural observations revealed a uniform dispersion of nano sized Si Cp without any agglomeration problem and well bonded with copper matrix at different process parameter combinations. X-ray diffraction study shows that no intermetallic compound was produced after processing. The microhardness of nano composites was remarkably enhanced and about 95% more than that of copper matrix
Fabrication of Surface Level Cu/SiCp Nanocomposites by Friction Stir Processing Route
Directory of Open Access Journals (Sweden)
Cartigueyen Srinivasan
Full Text Available Friction stir processing (FSP technique has been successfully employed as low energy consumption route to prepare copper based surface level nanocomposites reinforced with nanosized silicon carbide particles (SiCp. The effect of FSP parameters such as tool rotational speed, processing speed, and tool tilt angle on microstructure and microhardness was investigated. Single pass FSP was performed based on Box-Behnken design at three factors in three levels. A cluster of blind holes 2 mm in diameter and 3 mm in depth was used as particulate deposition technique in order to reduce the agglomeration problem during composite fabrication. K-type thermocouples were used to measure temperature histories during FSP. The results suggest that the heat generation during FSP plays a significant role in deciding the microstructure and microhardness of the surface composites. Microstructural observations revealed a uniform dispersion of nanosized SiCp without any agglomeration problem and well bonded with copper matrix at different process parameter combinations. X-ray diffraction study shows that no intermetallic compound was produced after processing. The microhardness of nanocomposites was remarkably enhanced and about 95% more than that of copper matrix.
Experimental Evaluation of a Water Shield for a Surface Power Reactor
Pearson, J. Boise; Reid, Robert S.
As part of the Vision for Space Exploration the end of the next decade will bring man back to the surface of the moon. One of the most critical issues for the establishment of human presence on the moon will be the availability of compact power sources. The establishment of man on the moon will require power from greater than 10's of kWt's in follow on years. Nuclear reactors are extremely we11 suited to meet the needs for power generation on the lunar or Martian surface. reactor system. Several competing concepts exist for lightweight, safe, robust shielding systems such as a water shield, lithium hydride (LiH), Boron Carbide, and others. Water offers several potential advantages, including reduced cost, reduced technical risk, and reduced mass. Water has not typically been considered for space reactor applications because of the need for gravity to remove the potential for radiation streaming paths. The water shield concept relies on predictions of passive circulation of the shield water by natural convection to adequately cool the shield. This prediction needs to be experimentally evaluated, especially for shields with complex geometries. MSFC has developed the experience and fac necessary to do this evaluation in the Early Flight Fission - Test Facility (EFF-TF).
Energy Technology Data Exchange (ETDEWEB)
REID, ROBERT S. [Los Alamos National Laboratory; PEARSON, J. BOSIE [Los Alamos National Laboratory; STEWART, ERIC T. [Los Alamos National Laboratory
Water based reactor shielding is being investigated for use on initial lunar surface power systems. A water shield may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a 100 kWt lunar surface reactor shield design is evaluated with 2 kW power input to the water in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to validate a CFD model. Performance of the water shield on the lunar surface is then predicted with a CFD model anchored to test data. The experiment had a maximum water temperature of 75 C. The CFD model with 1/6-g predicts a maximum water temperature of 88 C with the same heat load and external boundary conditions. This difference in maximum temperature does not greatly affect the structural design of the shield, and demonstrates that it may be possible to use water for a lunar reactor shield.
Effects of nitrogen source availability and bioreactor operating strategies on lutein production with Scenedesmus obliquus FSP-3.
Ho, Shih-Hsin; Xie, Youping; Chan, Ming-Chang; Liu, Chen-Chun; Chen, Chun-Yen; Lee, Duu-Jong; Huang, Chieh-Chen; Chang, Jo-Shu
In this study, the effects of the type and concentration of nitrogen sources on the cell growth and lutein content of an isolated microalga Scenedesmus obliquus FSP-3 were investigated. With batch culture, the highest lutein content (4.61 mg/g) and lutein productivity (4.35 mg/L/day) were obtained when using 8.0 mM calcium nitrate as the nitrogen source. With this best nitrogen source condition, the microalgae cultivation was performed using two bioreactor strategies (namely, semi-continuous and two-stage operations) to further enhance the lutein content and productivity. Using semi-continuous operation with a 10% medium replacement ratio could obtain the highest biomass productivity (1304.8 mg/L/day) and lutein productivity (6.01 mg/L/day). This performance is better than most related studies. Copyright © 2014 Elsevier Ltd. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
The objective of this evaluation is to provide recommendations to ensure consistency between the technical baseline requirements, baseline design, and the alternate constructed power system. Recommendations for resolving discrepancies between the alternate constructed power system, the technical baseline requirements, and the baseline design are included in this report. Cost and schedule estimates are provided for all recommended modifications. This report does not address items which do not meet current safety or code requirements. These items are identified to the CMO and immediate action is taken to correct the situation. The report does identify safety and code items for which the A/E is recommending improvements. The recommended improvements will exceed the minimum requirements of applicable code and safety guidelines. These recommendations are intended to improve and enhance the operation and maintenance of the facility. This Title III Evaluation Report (TER) does not include evaluation of surface electrical construction support facilities used to provide temporary construction power where the intent to remove such facilities when construction is completed such as tent storage buildings, shop buildings, fuel storage area etc. Furthermore, this TER does not include the extension of the existing overhead power lines to the booster pump station that was designed, installed, and is maintained by Nevada Test Site (NTS).
Overview of Multi-Kilowatt Free-Piston Stirling Power Conversion Research at GRC
International Nuclear Information System (INIS)
Geng, Steven M.; Mason, Lee S.; Dyson, Rodger W.; Penswick, L. Barry
As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free-piston Stirling convertors and a pair of commercially available pressure wave generators (which will be plumbed together to create a high power Stirling linear alternator test rig) have been procured for in-house testing at Glenn Research Center. Delivery of both the Stirling convertors and the linear alternator test rig is expected by October, 2007. The 1 kW class free-piston Stirling convertors will be tested at GRC to map and verify performance. The convertors will later be modified to operate with a NaK liquid metal pumped loop for thermal energy input. The high power linear alternator test rig will be used to map and verify high power Stirling linear alternator performance and to develop power management and distribution (PMAD) methods and techniques. This paper provides an overview of the multi-kilowatt free-piston Stirling power conversion work being performed at GRC
Laser surface remelting and hardening of an automotive shaft sing a high-power fiber laser
Directory of Open Access Journals (Sweden)
Milton Sergio Fernandes de Lima
Full Text Available An automotive shaft was surface-remelted and hardened using a 2 kW fiber laser and an adapted linear axis whose rotating axis produced helical tracks at 120 RPM. The process variable was the laser power, ranging from 300 to 1100 W, which produced two regions in the material: a martensitic region (MR and a partially transformed region (PTR. The MR is formed after rapid solidification or austenitization followed by rapid cooling (10(7 K.s-1. The PTR is composed of martensite, unchanged pearlite and proeutectoid ferrite. The maximum case depth was about 0.3 mm. The microhardness inside the martensitic regions are at least double that of the base material, i.e. between 800 than 600 HV compared to 300 HV. Thermal simulations using a modified Rosenthal formalism help elucidate the phase transformation inside the material and show good agreement with experimental results. The experimental laser-steel absorptivities were measured; they ranged between 38 and 59% depending on the laser power and the amount of liquid at the surface.
Analysis of Stationary, Photovoltaic-based Surface Power System Designs at the Lunar South Pole
Freeh, Joshua E.
Combinations of solar arrays and either batteries or regenerative fuel cells are analyzed for a surface power system module at the lunar south pole. The systems are required to produce 5 kW of net electrical power in sunlight and 2 kW of net electrical power during lunar night periods for a 10-year period between 2020 and 2030. Systems-level models for energy conservation, performance, degradation, and mass are used to compare to various systems. The sensitivities of important and/or uncertain variables including battery specific energy, fuel cell operating voltage, and DC-DC converter efficiency are compared to better understand the system. Switching unit efficiency, battery specific energy, and fuel cell operating voltage appear to be important system-level variables for this system. With reasonably sized solar arrays, the regenerative fuel cell system has significantly lower mass than the battery system based on the requirements and assumptions made herein. The total operational time is estimated at about 10,000 hours in battery discharge/fuel cell mode and about 4,000 and 8,000 hours for the battery charge and electrolyzer modes, respectively. The estimated number of significant depth-of-discharge cycles for either energy storage system is less than 100 for the 10-year period.
Investigation of the delay time distribution of high power microwave surface flashover
Foster, J.; Krompholz, H.; Neuber, A.
Characterizing and modeling the statistics associated with the initiation of gas breakdown has proven to be difficult due to a variety of rather unexplored phenomena involved. Experimental conditions for high power microwave window breakdown for pressures on the order of 100 to several 100 torr are complex: there are little to no naturally occurring free electrons in the breakdown region. The initial electron generation rate, from an external source, for example, is time dependent and so is the charge carrier amplification in the increasing radio frequency (RF) field amplitude with a rise time of 50 ns, which can be on the same order as the breakdown delay time. The probability of reaching a critical electron density within a given time period is composed of the statistical waiting time for the appearance of initiating electrons in the high-field region and the build-up of an avalanche with an inherent statistical distribution of the electron number. High power microwave breakdown and its delay time is of critical importance, since it limits the transmission through necessary windows, especially for high power, high altitude, low pressure applications. The delay time distribution of pulsed high power microwave surface flashover has been examined for nitrogen and argon as test gases for pressures ranging from 60 to 400 torr, with and without external UV illumination. A model has been developed for predicting the discharge delay time for these conditions. The results provide indications that field induced electron generation, other than standard field emission, plays a dominant role, which might be valid for other gas discharge types as well.
Substantial difference in target surface chemistry between reactive dc and high power impulse magnetron sputtering
Greczynski, G.; Mráz, S.; Schneider, J. M.; Hultman, L.
The nitride layer formed in the target race track during the deposition of stoichiometric TiN thin films is a factor 2.5 thicker for high power impulse magnetron sputtering (HIPIMS), compared to conventional dc processing (DCMS). The phenomenon is explained using x-ray photoelectron spectroscopy analysis of the as-operated Ti target surface chemistry supported by sputter depth profiles, dynamic Monte Carlo simulations employing the TRIDYN code, and plasma chemical investigations by ion mass spectrometry. The target chemistry and the thickness of the nitride layer are found to be determined by the implantation of nitrogen ions, predominantly N+ and N2+ for HIPIMS and DCMS, respectively. Knowledge of this method-inherent difference enables robust processing of high quality functional coatings.
A Comparison of Fission Power System Options for Lunar and Mars Surface Applications
International Nuclear Information System (INIS)
Mason, Lee S.
This paper presents a comparison of reactor and power conversion design options for 50 kWe class lunar and Mars surface power applications with scaling from 25 to 200 kWe. Design concepts and integration approaches are provided for three reactor-converter combinations: gas-cooled Brayton, liquid-metal Stirling, and liquid-metal thermoelectric. The study examines the mass and performance of low temperature, stainless steel based reactors and higher temperature refractory reactors. The preferred system implementation approach uses crew-assisted assembly and in-situ radiation shielding via installation of the reactor in an excavated hole. As an alternative, self-deployable system concepts that use earth-delivered, on-board radiation shielding are evaluated. The analyses indicate that among the 50 kWe stainless steel reactor options, the liquid-metal Stirling system provides the lowest mass at about 5300 kg followed by the gas-cooled Brayton at 5700 kg and the liquid-metal thermoelectric at 8400 kg. The use of a higher temperature, refractory reactor favors the gas-cooled Brayton option with a system mass of about 4200 kg as compared to the Stirling and thermoelectric options at 4700 kg and 5600 kg, respectively. The self-deployed concepts with on-board shielding result in a factor of two system mass increase as compared to the in-situ shielded concepts
Power monitoring in dielectric-loaded surface plasmon-polariton waveguides.
Kumar, Ashwani; Gosciniak, Jacek; Andersen, Thomas B; Markey, Laurent; Dereux, Alain; Bozhevolnyi, Sergey I
We report on propagating mode power monitoring in dielectric-loaded surface plasmon-polariton waveguides (DLSPPWs) by measuring the resistance of gold stripes supporting the DLSPPW mode propagation. Inevitable absorption of the DLSPPW mode in metal causes an increase in the stripe temperature and, thereby, in its resistance whose variations are monitored with an external Wheatstone bridge being accurately balanced in the absence of radiation in a waveguide. The investigated waveguide configuration consists of a 1-µm-thick and 10-µm-wide polymer ridges tapered laterally to a 1-µm-wide ridge placed on a 50-nm-thin and 4-µm-wide gold stripe, all supported by a magnesium fluoride substrate. Using single-mode polarization-maintaining fiber for in- and out-coupling of radiation, DLSPPW mode power monitoring at telecom wavelengths is realized with the responsivities of up to ~1.8 µV/µW (showing weak wavelength dependence) being evaluated for a bias voltage of 1 V.
100-kWe Lunar/Mars surface power utilizing the SP-100 reactor with dynamic conversion
International Nuclear Information System (INIS)
Harty, R.B.; Mason, L.S.
An integration study was performed coupling an SP-100 reactor with either a Brayton or Stirling power conversion subsystem. A power level of 100 kWe was selected for the study. The power system was to be compatible with both the lunar and Mars surface environment and require no site preparation. In addition, the reactor was to have integral shielding and be completely self-contained, including its own auxiliary power for start-up. Initial reliability studies were performed to determine power conversion redundancy and engine module size. Previous studies were used to select the power conversion optimum operating conditions (ratio of hot-side temperature to cold-side temperature). Results of the study indicated that either the Brayton or Stirling power conversion subsystems could be integrated with the SP-100 reactor for either a lunar or Mars surface power application. For the lunar environment, the reactor and primary coolant loop would be contained in a guard vessel to protect from a loss of primary loop containment. For the Mars environment, all refractory components including the reactor, primary coolant, and power conversion components would be contained in a vacuum vessel for protection against the CO 2 environment. The vacuum would be maintained by an active ion pumping system. These active ion vacuum systems have no moving parts and have a long history of reliable operation
A major invasion of transposable elements accounts for the large size of the Blumeria graminis f.sp. tritici genome.
Parlange, Francis; Oberhaensli, Simone; Breen, James; Platzer, Matthias; Taudien, Stefan; Simková, Hana; Wicker, Thomas; Doležel, Jaroslav; Keller, Beat
Powdery mildew of wheat (Triticum aestivum L.) is caused by the ascomycete fungus Blumeria graminis f.sp. tritici. Genomic approaches open new ways to study the biology of this obligate biotrophic pathogen. We started the analysis of the Bg tritici genome with the low-pass sequencing of its genome using the 454 technology and the construction of the first genomic bacterial artificial chromosome (BAC) library for this fungus. High-coverage contigs were assembled with the 454 reads. They allowed the characterization of 56 transposable elements and the establishment of the Blumeria repeat database. The BAC library contains 12,288 clones with an average insert size of 115 kb, which represents a maximum of 7.5-fold genome coverage. Sequencing of the BAC ends generated 12.6 Mb of random sequence representative of the genome. Analysis of BAC-end sequences revealed a massive invasion of transposable elements accounting for at least 85% of the genome. This explains the unusually large size of this genome which we estimate to be at least 174 Mb, based on a large-scale physical map constructed through the fingerprinting of the BAC library. Our study represents a crucial step in the perspective of the determination and study of the whole Bg tritici genome sequence.
Effect of corn steep liquor on lettuce root rot (Fusarium oxysporum f.sp. lactucae) in hydroponic cultures.
Chinta, Yufita D; Kano, Kazuki; Widiastuti, Ani; Fukahori, Masaru; Kawasaki, Shizuka; Eguchi, Yumi; Misu, Hideyuki; Odani, Hiromitsu; Zhou, Songying; Narisawa, Kazuhiko; Fujiwara, Kazuki; Shinohara, Makoto; Sato, Tatsuo
Recent reports indicate that organic fertilisers have a suppressive effect on the pathogens of plants grown under hydroponic systems. Furthermore, microorganisms exhibiting antagonistic activity to diseases have been observed in organic hydroponic systems. This study evaluated the effect of corn steep liquor (CSL) on controlling lettuce root rot disease [Fusarium oxysporum f.sp. lactucae (FOL)] in a hydroponic system. The effect of CSL and Otsuka A (a chemical fertiliser) on the inhibition of FOL in terms of mycelial growth inhibition was tested in vivo. Addition of CSL suppressed FOL infection rates. CSL inhibited FOL infection by 26.3-42.5% from 2 days after starting incubation. In comparison, Otsuka A inhibited FOL growth by 5.5-19.4%. In addition, four of 10 bacteria isolated from the nutrient media containing CSL exhibited inhibition zones preventing FOL mycelial growth. We found that CSL suppressed FOL in lettuce via its antifungal and biostimulatory effects. We suggest that activation of beneficial microorganisms present in CSL may be used to decrease lettuce root rot disease and contribute to lettuce root growth. © 2014 Society of Chemical Industry.
Microstructure and microhardness of AA1050/TiC surface composite ...
Indian Academy of Sciences (India)
FSP) has been developed by several researchersto produce an upper surface modification of metallic materials. The fabrication of TiC ... A tool made of HCHCr steel, oil hardened to 62 HRC, having a cylindrical profile was used in this study.
Effective Low-Power Wearable Wireless Surface EMG Sensor Design Based on Analog-Compressed Sensing
Directory of Open Access Journals (Sweden)
Mohammadreza Balouchestani
Full Text Available Surface Electromyography (sEMG is a non-invasive measurement process that does not involve tools and instruments to break the skin or physically enter the body to investigate and evaluate the muscular activities produced by skeletal muscles. The main drawbacks of existing sEMG systems are: (1 they are not able to provide real-time monitoring; (2 they suffer from long processing time and low speed; (3 they are not effective for wireless healthcare systems because they consume huge power. In this work, we present an analog-based Compressed Sensing (CS architecture, which consists of three novel algorithms for design and implementation of wearable wireless sEMG bio-sensor. At the transmitter side, two new algorithms are presented in order to apply the analog-CS theory before Analog to Digital Converter (ADC. At the receiver side, a robust reconstruction algorithm based on a combination of ℓ1-ℓ1-optimization and Block Sparse Bayesian Learning (BSBL framework is presented to reconstruct the original bio-signals from the compressed bio-signals. The proposed architecture allows reducing the sampling rate to 25% of Nyquist Rate (NR. In addition, the proposed architecture reduces the power consumption to 40%, Percentage Residual Difference (PRD to 24%, Root Mean Squared Error (RMSE to 2%, and the computation time from 22 s to 9.01 s, which provide good background for establishing wearable wireless healthcare systems. The proposed architecture achieves robust performance in low Signal-to-Noise Ratio (SNR for the reconstruction process.
Nanotechnology based surface treatments for corrosion protection and deposit control of power plant equipment. Phase 1
Energy Technology Data Exchange (ETDEWEB)
Nanotechnology can provide possibilities for obtaining new valuable information regarding performance and corrosion protection in power plants. In general the desired performance of the contact surfaces is an easy-to-release effect. This is in order to prolong the time interval between cleaning periods or make the cleaning procedures easier and less expensive. Corrosion protection is also desired in order to extend the life time of various parts in the power plants and thus optimize the energy output and overall efficiency of the plant. Functional sol-gel coating based on nanotechnology is tested in a variety of conditions. Applications of functional sol-gel coatings were performed in the condenser and on seven air preheaters at Fynsvaerket, Odense, with corrosion protection as the main issue. Coatings with easy-to-clean effects were tested in the Flue Gas Desulphurization plant at Nordjyllandsvaerket, Aalborg, with the aim of reducing gipsum deposit. Thermo stabilized coatings were tested on tube bundles between in the passage from the 1st to 2end pass and on the wall between 1st and 2end pass at Amagervaerket, Copenhagen, and in the boiler at Haderslev CHP plant. The objective of this test were reducing deposits and increasing corrosion protection. The tested coatings were commercial available coatings and coatings developed in this project. Visual inspections have been performed of all applications except at Nordjyllandsvaerket. Corrosion assessment has been done at DTU - Mechanical Engineering. The results range from no difference between coated and uncoated areas to some improvements. At Amagervaerket the visual assessment showed in general a positive effect with a sol-gel hybrid system and a commercial system regarding removal of deposits. The visual assessment of the air preheaters at Fynsvaerket indicates reduced deposits on a sol-gel nanocomposite coated air preheater compared to an uncoated air preheater. (Author)
Insulated gate and surface passivation structures for GaN-based power transistors
Yatabe, Zenji; Asubar, Joel T.; Hashizume, Tamotsu
Recent years have witnessed GaN-based devices delivering their promise of unprecedented power and frequency levels and demonstrating their capability as an able replacement for Si-based devices. High-electron-mobility transistors (HEMTs), a key representative architecture of GaN-based devices, are well-suited for high-power and high frequency device applications, owing to highly desirable III-nitride physical properties. However, these devices are still hounded by issues not previously encountered in their more established Si- and GaAs-based devices counterparts. Metal-insulator-semiconductor (MIS) structures are usually employed with varying degrees of success in sidestepping the major problematic issues such as excessive leakage current and current instability. While different insulator materials have been applied to GaN-based transistors, the properties of insulator/III-N interfaces are still not fully understood. This is mainly due to the difficulty of characterizing insulator/AlGaN interfaces in a MIS HEMT because of the two resulting interfaces: insulator/AlGaN and AlGaN/GaN, making the potential modulation rather complicated. Although there have been many reports of low interface-trap densities in HEMT MIS capacitors, several papers have incorrectly evaluated their capacitance-voltage (C-V) characteristics. A HEMT MIS structure typically shows a 2-step C-V behavior. However, several groups reported C-V curves without the characteristic step at the forward bias regime, which is likely to the high-density states at the insulator/AlGaN interface impeding the potential control of the AlGaN surface by the gate bias. In this review paper, first we describe critical issues and problems including leakage current, current collapse and threshold voltage instability in AlGaN/GaN HEMTs. Then we present interface properties, focusing on interface states, of GaN MIS systems using oxides, nitrides and high-κ dielectrics. Next, the properties of a variety of AlGaN/GaN MIS
Insulated gate and surface passivation structures for GaN-based power transistors
International Nuclear Information System (INIS)
Yatabe, Zenji; Asubar, Joel T; Hashizume, Tamotsu
Recent years have witnessed GaN-based devices delivering their promise of unprecedented power and frequency levels and demonstrating their capability as an able replacement for Si-based devices. High-electron-mobility transistors (HEMTs), a key representative architecture of GaN-based devices, are well-suited for high-power and high frequency device applications, owing to highly desirable III-nitride physical properties. However, these devices are still hounded by issues not previously encountered in their more established Si- and GaAs-based devices counterparts. Metal–insulator–semiconductor (MIS) structures are usually employed with varying degrees of success in sidestepping the major problematic issues such as excessive leakage current and current instability. While different insulator materials have been applied to GaN-based transistors, the properties of insulator/III-N interfaces are still not fully understood. This is mainly due to the difficulty of characterizing insulator/AlGaN interfaces in a MIS HEMT because of the two resulting interfaces: insulator/AlGaN and AlGaN/GaN, making the potential modulation rather complicated. Although there have been many reports of low interface-trap densities in HEMT MIS capacitors, several papers have incorrectly evaluated their capacitance–voltage ( C – V ) characteristics. A HEMT MIS structure typically shows a 2-step C – V behavior. However, several groups reported C – V curves without the characteristic step at the forward bias regime, which is likely to the high-density states at the insulator/AlGaN interface impeding the potential control of the AlGaN surface by the gate bias. In this review paper, first we describe critical issues and problems including leakage current, current collapse and threshold voltage instability in AlGaN/GaN HEMTs. Then we present interface properties, focusing on interface states, of GaN MIS systems using oxides, nitrides and high- κ dielectrics. Next, the properties of a
DEFF Research Database (Denmark)
Elmholdt, Claus Westergård; Fogsgaard, Morten
In this chapter, we will explore the dynamics of power in processes of creativity, and show its paradoxical nature as both a bridge and a barrier to creativity in organisations. Recent social psychological experimental research (Slighte, de Dreu & Nijstad, 2011) on the relation between power...... and floating source for empowering people in the organisation. We will explore and discuss here the potentials, challenges and pitfalls of power in relation to creativity in the life of organisations today. The aim is to demonstrate that power struggles may be utilised as constructive sources of creativity...
Foulant Characteristics Comparison in Recycling Cooling Water System Makeup by Municipal Reclaimed Water and Surface Water in Power Plant
Ping, Xu; Jing, Wang; Yajun, Zhang; Jie, Wang; Shuai, Si
Due to water shortage, municipal reclaimed water rather than surface water was replenished into recycling cooling water system in power plants in some cities in China. In order to understand the effects of the measure on carbon steel corrosion, characteristics of two kinds of foulant produced in different systems were studied in the paper. Differences between municipal reclaimed water and surface water were analyzed firstly. Then, the weight and the morphology of two kinds of foulant were com...
Surface morphology and surface energy of anode materials influence power outputs in a multi-channel mediatorless bio-photovoltaic (BPV) system.
Bombelli, Paolo; Zarrouati, Marie; Thorne, Rebecca J; Schneider, Kenneth; Rowden, Stephen J L; Ali, Akin; Yunus, Kamran; Cameron, Petra J; Fisher, Adrian C; Ian Wilson, D; Howe, Christopher J; McCormick, Alistair J
Bio-photovoltaic cells (BPVs) are a new photo-bio-electrochemical technology for harnessing solar energy using the photosynthetic activity of autotrophic organisms. Currently power outputs from BPVs are generally low and suffer from low efficiencies. However, a better understanding of the electrochemical interactions between the microbes and conductive materials will be likely to lead to increased power yields. In the current study, the fresh-water, filamentous cyanobacterium Pseudanabaena limnetica (also known as Oscillatoria limnetica) was investigated for exoelectrogenic activity. Biofilms of P. limnetica showed a significant photo response during light-dark cycling in BPVs under mediatorless conditions. A multi-channel BPV device was developed to compare quantitatively the performance of photosynthetic biofilms of this species using a variety of different anodic conductive materials: indium tin oxide-coated polyethylene terephthalate (ITO), stainless steel (SS), glass coated with a conductive polymer (PANI), and carbon paper (CP). Although biofilm growth rates were generally comparable on all materials tested, the amplitude of the photo response and achievable maximum power outputs were significantly different. ITO and SS demonstrated the largest photo responses, whereas CP showed the lowest power outputs under both light and dark conditions. Furthermore, differences in the ratios of light : dark power outputs indicated that the electrochemical interactions between photosynthetic microbes and the anode may differ under light and dark conditions depending on the anodic material used. Comparisons between BPV performances and material characteristics revealed that surface roughness and surface energy, particularly the ratio of non-polar to polar interactions (the CQ ratio), may be more important than available surface area in determining biocompatibility and maximum power outputs in microbial electrochemical systems. Notably, CP was readily outperformed by all
Response surface methodology and optimization of solar powered reverse osmosis plant for brackish water desalination
Energy Technology Data Exchange (ETDEWEB)
Khayet, M.; Essalhi, M.; Cojocaru, C. [Univ. Complutense of Madrid, Madrid (Spain). Dept. of Applied Physics; Armenta-Deu, C. [Univ. Complutense of Madrid, Madrid (Spain). Dept. of Atomic Molecular and Nuclear Physics; Hilal, N. [Nottingham Univ., Nottingham (United Kingdom). Faculty of Engineering, Centre for Clear Water Technologies
The costs and energy consumption associated with reverse osmosis (RO) desalination have decreased significantly in recent years due to the development of novel membranes and modules with high RO performance. In addition, adequate pretreatment processes are now used with along with energy recovery devices and renewable energy systems. Response surface methodology (RSM) was used in this study to develop a predictive model that characterized the general response of a brackish water reverse osmosis (BWRO) plant to determine the optimum operating conditions and the RO specific performance index. The RSM methodology allowed factors to be simultaneously varied between minimum and maximum values. The significance of the RSM polynomial model was determined by analysis of variance (ANOVA). The predicted and experimental responses of the BWRO plant were in good agreement. Optimization was carried out using canonical analysis and the step adjusting gradient method to ensure high quantity and quality potable water production with low energy consumption. The input variables were the feed temperature, the feed flow-rate and the feed pressure. The BWRO plant was powered with photovoltaic panels and a solar thermal collector. For a brackish water of 6 g/L salt concentration, the optimized BWRO plant guaranteed a production of 0.2 m{sup 3}/day with an energy consumption less than 1.3 kWh/m{sup 3}. 6 refs., 1 tab., 2 figs.
Control and dynamics study for the satellite power system. Volume 1: MPTS/SPS collector dynamic analysis and surface deformation
Wang, S. J.
The basic dynamic properties and performance characteristics of the microwave power transmission satellite antenna were analyzed in an effort to develop criteria, requirements, and constraints for the control and structure design. The vibrational properties, the surface deformation, and the corresponding scan loss under the influence of disturbances are considered.
Alcohol dehydrogenase 1 of barley modulates susceptibility to the parasitic fungus Blumeria graminis f.sp. hordei.
Pathuri, Indira Priyadarshini; Reitberger, Ines E; Hückelhoven, Ralph; Proels, Reinhard K
Plant primary energy metabolism is profoundly reorganized under biotic stress conditions and there is increasing evidence for a role for the fermentative pathway in biotic interactions. However, the mechanisms regulating metabolic reprogramming are not well understood despite its critical function in the biotic stress response. Here the function of alcohol dehydrogenase (ADH) in the interaction of barley with the parasitic fungus Blumeria graminis f.sp. hordei (Bgh) is addressed. Challenge of susceptible barley leaves with Bgh resulted in transcriptional activation of HvADH1 and an induction of ADH enzyme activity starting 24 h after infection and reaching a clear-cut effect 4 d after infection. This increase in ADH enzyme activity was not observed in the resistant near-isogenic mlo5 line. Moreover, an induction of ADH enzyme activity by Bgh was enhanced in the presence of sucrose in hydroponically grown seedlings. Transient knock-down or overexpression of HvADH1 in barley epidermal cells mediated a decrease or increase in the penetration success of Bgh, respectively. Inhibition of ADH activity by pyrazole resulted in a delay in symptoms. The pyrazole effect could be overcome by adding glucose to the incubation medium, pinpointing a nutritional effect of ADH in the barley-Bgh interaction. Taken together, misexpression of pathogen-inducible HvADH1 or variation of ADH activity modulates the pathogen response of barley to the biotrophic fungal parasite Bgh. In this way, ADH knock-down/inhibition results in reduced fungal success. The possibility is discussed that ADH activity supports biotrophy by maintaining glycolytic metabolism in pathogen-stressed barley.
The use of surface power for characterisation of structure-borne sound sources of low modal density
DEFF Research Database (Denmark)
Ohlrich, Mogens
The use of the surface power methods for source characterisaiton of vibrating machinery of low modal density is investigated in this paper. It was demonstrated by Ohlrich and Larsen that this relatively simple, but very useful measurement technique for quantifying the vibratory strength...... of machinery, is very suitable in cases of high modal density, especially with respect to overall evaluation of machinery vibration characteristics and for estimation of the power produced by internal source mechanisms of the machine. Thus, it is envisaged that the method can be used in the development stage...... of new machines, in comparison studies of different machines, and in factory quality control to ensure that vibro-acoustic specifications are met. Carefully controlled experiments with an instrumented 3/4-scale structural model of a helicopter gearbox of low modal density, show that the surface power...
Er,Cr:YSGG Laser Energy Delivery: Pulse and Power Effects on Enamel Surface and Erosive Resistance.
de Oliveira, Renan Mota; de Souza, Vinicius Matsuzaki; Esteves, Camila Machado; de Oliveira Lima-Arsati, Ynara Bosco; Cassoni, Alessandra; Rodrigues, José Augusto; Brugnera Junior, Aldo
High power lasers have been suggested as a useful tool for dental caries and erosion prevention due to the increase of enamel acid resistance. to evaluate the effect of Er,Cr:YSGG (erbium,chromium:yttrium, scandium, gallium, garnet) laser irradiation pulse frequency and power on enamel surface and acid erosion resistance. By combining pulse frequency (5-75 Hz) and power settings (0.10-1.00 W), 20 irradiated groups and one nonirradiated control group were tested. A total of 63 bovine enamel blocks (n = 3/group) were prepared for surface hardness and roughness evaluation, performed in three phases: baseline, after irradiation, and after erosive challenge. Enamel blocks were irradiated with Er,Cr:YSGG laser with MZ8 tip (iPlus; Waterlase, Biolase, CA) for 30 sec according to experimental group and submitted. Erosive challenge consisted of four cycles alternating immersion in 0.01 M HCl (5 mL/mm 2 ; 2 min; at 37°C) and immersion in artificial saliva for 3 h. Analysis of variance (three-way ANOVA), Tukey's test, and Pearson correlation were performed for the statistical analysis (p hardness. After erosive challenge, 5 and 75 W groups showed increase in surface hardness; 0.25, 0.5, 0.75, and 1 W groups showed minor alterations in surface roughness. the irradiation of Er,Cr:YSGG laser with different parameters of power and pulse frequency settings may alter enamel surface and erosive resistance differently. Pulse frequency of 30 Hz and power of 0.50 W was considered the best parameter to prevent enamel acid erosion.
The impact of membrane surface charges on the ion transport in MoS2 nanopore power generators
Huang, Zhuo; Zhang, Yan; Hayashida, Tomoki; Ji, Ziwei; He, Yuhui; Tsutsui, Makusu; Miao, Xiang Shui; Taniguchi, Masateru
Recent experiments demonstrated giant osmotic effects induced in a single-atomic-layer MoS2 nanopore by imposing a KCl concentration bias, thereby highlighting the prospect of ultrathin nanopores as power generators. In this work, we report on an electrokinetic analysis of the ionic transport in the MoS2 nanopore system. By taking membrane surface chemistry into account, we found profound roles of surface charges in and out of the nanopore on the cross-pore ion transport, which shed light on the intriguing experimental observations of a high pore conductance with a large open-circuit voltage in the MoS2 system. The present work establishes a theoretical model capable of dealing with ultrathin membrane surface charges for evaluating the energy conversion performance of nanopore power generators constructed with two-dimensional materials.
Space solar power stations. Problems of energy generation and using its on the earth surface and nearest cosmos
Sinkevich, OA; Gerasimov, DN; Glazkov, VV
Three important physical and technical problems for solar power stations (SPS) are considered: collection of solar energy and effective conversion of this energy to electricity in space power stations, energy transportation by the microwave beam to the Earth surface and direct utilization of the microwave beam energy for global environmental problems. Effectiveness of solar energy conversion into electricity in space power stations using gas and steam turbines plants, and magneto-hydrodynamic generator (MHDG) are analyzed. The closed cycle MHDG working on non–equilibrium magnetized plasmas of inert gases seeded with the alkaline metal vapors are considered. The special emphases are placed on MHDG and gas-turbine installations that are operating without compressor. Also opportunities for using the produced by space power stations energy for ecological needs on Earth and in Space are discussed.
Phenotypic evaluation of the resistance in F1 carnation populations to vascular wilt caused by Fusarium oxysporum f.sp. dianthi
Directory of Open Access Journals (Sweden)
Johana Carolina Soto-Sedano
Full Text Available One of the most important phytosanitary problems of the carnation crops in Colombia and in the entire world is vascular wilting produced by Fusarium oxysporum f.sp. dianthi. Currently, an effective treatment against the pathogen does not exist; the search for resistant varieties has been the most successful method for control of this disease. Breeding programs are vital to solving the problem of the carnation fusariosis. The objective of this research was the phenotypic evaluation of carnation F1 populations, products of contrasting crossing, resistant per susceptible to F. oxysporum f.sp. dianthi, in order to determine if the resistance is inherited in the lines. This information will contribute to the selection of material and to the successful introduction of the resistant characteristic, whose expression is commercially acceptable, to the gene pool. The methodology adopted was a phenotypic evaluation of the response to the parasite in the population (450 individuals and in the parental. This evaluation estimated the area under the curve (AU DPC, using a scale of symptoms reported for carnation vascular wilt. Three different phenotypes were established with this evaluation. The moderately susceptible one is the predominant phenotype and an analysis of phenotypic frequencies was carried out on it. The results show that the individuals of the evaluated F1 population were distributed between two extreme ranges, resistant and susceptible; this shows that there is segregation for the trait resistant to F. oxysporum f.sp dianthi. We did not observe clearly differentiated classes, i.e. with complete absence or presence of the disease, indicating a possible control of the resistance in the evaluated carnation material, governed by more than one gene and with a possible additive genetic action
Comparative Proteomic Analysis of Different Isolates of Fusarium oxysporum f.sp. lycopersici to Exploit the Differentially Expressed Proteins Responsible for Virulence on Tomato Plants
Directory of Open Access Journals (Sweden)
Rajendran Manikandan
Full Text Available The vascular wilt of tomato caused by Fusarium oxysporum f.sp. lycopersici is an important soil borne pathogen causes severe yield loss. The molecular characterization and their interaction with its host is necessary to develop a protection strategy. 20 isolates of F. oxysporum f.sp. lycopersici (FOL were isolated from wilt infected tomato plants across Tamil Nadu. They were subjected to cultural, morphological, molecular and virulence studies. The results revealed that all the isolates produced both micro and macro conidia with different size, number of cells. The colors of the culture and growth pattern were also varied. In addition, chlamydospores were observed terminally and intercalary. The PCR analysis with F. oxysporum species-specific primer significantly amplified an amplicon of 600 bp fragment in all the isolates. Based on the above characters and pathogenicity, isolate FOL-8 was considered as virulent and FOL-20 was considered as least virulent. Proteomics strategy was adopted to determine the virulence factors between the isolates of FOL-8 and FOL-20. The 2D analyses have showed the differential expression of 17 different proteins. Among them, three proteins were down regulated and 14 proteins were significantly up regulated in FOL-8 than FOL-20 isolate. Among the 17 proteins, 10 distinct spots were analyzed by MALDI-TOF. The functions of the analyzed proteins, suggested that they were involved in pathogenicity, symptom expression and disease development, sporulation, growth, and higher penetration rate on tomato root tissue. Overall, these experiments proves the role of proteome in pathogenicity of F. oxysporum f.sp. lycopersici in tomato and unravels the mechanism behinds the virulence of the pathogen in causing wilt disease.
Genetic variation in Danish populations of Erysiphe graminis f.sp. hordei: estimation of gene diversity and effective population size using RFLP data
DEFF Research Database (Denmark)
Damgaard, C.; Giese, Nanna Henriette
. The average gene diversity, (H) over cap was estimated as 0.84. The effective population size was estimated as: log(10) ((N) over cap(e)) = 0.64 - log(10)(mu), or 4.4 x 10(9), assuming a nucleotide mutation rate (mu) of 10(-9) per base per generation. There was no significant genetic differentiation between......Genetic variation of the barley powdery mildew fungus (Erysiphe graminis f.sp. hordei) was estimated in three Danish local populations. Genetic variation was estimated from the variation amongst clones of Egh, and was therefore an estimate of the maximum genetic variation in the local populations...
Inhibition of charge recombination for enhanced dye-sensitized solar cells and self-powered UV sensors by surface modification
Energy Technology Data Exchange (ETDEWEB)
Chu, Liang, E-mail: email@example.com [Advanced Energy Technology Center, Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210046 (China); Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology (HUST), Wuhan 430074 (China); Qin, Zhengfei; Liu, Wei [School of Materials Science and Engineering (SMSE), Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210046 (China); Ma, Xin'guo, E-mail: email@example.com [Hubei Collaborative Innovation Center for High-efficiency Utilization of Solar Energy, Hubei University of Technology, Wuhan 430068 (China)
Graphical abstract: Inhibition of charge recombination was utilized to prolong electrode lifetime in dye-sensitized solar cells (DSSCs) and self-powered UV sensors based on TiO{sub 2}-modified SnO{sub 2} photoelectrodes. The electrochemical impedance spectroscopy and open-circuit voltage decay measurements indicated that the electron lifetime was significantly prolonged in DSSCs after TiO{sub 2} modification. And in self-powered UV sensors, the sensitivity and response time were enhanced. - Highlights: • The surface modification to inhibit charge recombination was utilized in photovoltaic devices. • Inhibition of charge recombination can prolong electrode lifetime in photovoltaic devices. • Enhanced DSSCs and self-powered UV sensors based on SnO{sub 2} photoelectrodes were obtained by TiO{sub 2} modification. - Abstract: The surface modification to inhibit charge recombination was utilized in dye-sensitized solar cells (DSSCs) and self-powered ultraviolet (UV) sensors based on SnO{sub 2} hierarchical microspheres by TiO{sub 2} modification. For DSSCs with SnO{sub 2} photoelectrodes modified by TiO{sub 2}, the power conversion efficiency (PCE) was improved from 1.40% to 4.15% under standard AM 1.5G illumination (100 mW/cm{sup 2}). The electrochemical impedance spectroscopy and open-circuit voltage decay measurements indicated that the charge recombination was effectively inhibited, resulting in long electron lifetime. For UV sensors with SnO{sub 2} photoelectrodes modified by TiO{sub 2} layer, the self-powered property was more obvious, and the sensitivity and response time were enhanced from 91 to 6229 and 0.15 s to 0.055 s, respectively. The surface modification can engineer the interface energy to inhibit charge recombination, which is a desirable approach to improve the performance of photoelectric nanodevice.
Laser Surface Treatment of Hydro and Thermal Power Plant Components and Their Coatings: A Review and Recent Findings
Mann, B. S.
High-power diode laser (HPDL) surface modification of hydro and thermal power plant components is of the utmost importance to minimize their damages occurring due to cavitation erosion, water droplet erosion, and particle erosion (CE, WDE, and PE). Special emphasis is given on the HPDL surface treatment of martensitic and precipitate-hardened stainless steels, Ti6Al4V alloy, plasma ion nitro-carburized layers, high pressure high velocity oxy-fuel and twin-wire arc sprayed coatings. WDE test results of all these materials and coatings in `untreated' and `HPDL- treated at 1550 °C' conditions, up to 8.55 million cycles, are already available. Their WDE testing was further continued up to 10.43 million cycles. The X20Cr13 and X10CrNiMoV1222, the most common martensitic stainless steels used in hydro and thermal power plants, were HPDL surface treated at higher temperature (1650 °C) and their WDE test results were also obtained up to 10.43 million cycles. It is observed that the increased HPDL surface temperature from 1550 to 1650 °C has resulted in significant improvement in their WDE resistances because of increased martensitic (ά) phase at higher temperature. After conducting long-range WDE tests, the correlation of CE, WDE, and PE resistances of these materials and protective coatings with their mechanical properties such as fracture toughness and microhardness product, ultimate resilience, modified resilience, and ultimate modified resilience has been reviewed and discussed. One of the edges of a 500 MW low pressure steam turbine moving blade (X10CrNiMoV1222 stainless steel) was HPDL surface treated at 1550 °C and its radii of curvatures and deflections were measured. These were compared with the data available earlier from a flat rectangular sample of similar composition and identical HPDL surface temperature.
A comparison of radioisotope Brayton and Stirling system for lunar surface mobile power
International Nuclear Information System (INIS)
Harty, R.B.
A study was performed by the Rocketdyne Division of Rockwell 2.5-kWe modular dynamic isotope power system (DIPS) using a Stirling power conversion system. The results of this study were compared with similar results performed under the DIPS program using a Brayton power conversion system. The study indicated that the Stirling power module has 20% lower mass and 40% lower radiator area than the Brayton module. However, the study also revealed that because the Stirling power module requires a complex heat pipe arrangment to transport heat from the isotope to the Stirling heater head and a pumped NaK heat rejection loop, the Stirling module is much more difficult to integrate with the isotope heat source and heat rejection system
The Effect of Surface Tension on the Gravity-driven Thin Film Flow of Newtonian and Power-law Fluids.
Hu, Bin; Kieweg, Sarah L
Gravity-driven thin film flow is of importance in many fields, as well as for the design of polymeric drug delivery vehicles, such as anti-HIV topical microbicides. There have been many prior works on gravity-driven thin films. However, the incorporation of surface tension effect has not been well studied for non-Newtonian fluids. After surface tension effect was incorporated into our 2D (i.e. 1D spreading) power-law model, we found that surface tension effect not only impacted the spreading speed of the microbicide gel, but also had an influence on the shape of the 2D spreading profile. We observed a capillary ridge at the front of the fluid bolus. Previous literature shows that the emergence of a capillary ridge is strongly related to the contact line fingering instability. Fingering instabilities during epithelial coating may change the microbicide gel distribution and therefore impact how well it can protect the epithelium. In this study, we focused on the capillary ridge in 2D flow and performed a series of simulations and showed how the capillary ridge height varies with other parameters, such as surface tension coefficient, inclination angle, initial thickness, and power-law parameters. As shown in our results, we found that capillary ridge height increased with higher surface tension, steeper inclination angle, bigger initial thickness, and more Newtonian fluids. This study provides the initial insights of how to optimize the flow and prevent the appearance of a capillary ridge and fingering instability.
The Effect of Surface Tension on the Gravity-driven Thin Film Flow of Newtonian and Power-law Fluids
Hu, Bin; Kieweg, Sarah L.
Gravity-driven thin film flow is of importance in many fields, as well as for the design of polymeric drug delivery vehicles, such as anti-HIV topical microbicides. There have been many prior works on gravity-driven thin films. However, the incorporation of surface tension effect has not been well studied for non-Newtonian fluids. After surface tension effect was incorporated into our 2D (i.e. 1D spreading) power-law model, we found that surface tension effect not only impacted the spreading speed of the microbicide gel, but also had an influence on the shape of the 2D spreading profile. We observed a capillary ridge at the front of the fluid bolus. Previous literature shows that the emergence of a capillary ridge is strongly related to the contact line fingering instability. Fingering instabilities during epithelial coating may change the microbicide gel distribution and therefore impact how well it can protect the epithelium. In this study, we focused on the capillary ridge in 2D flow and performed a series of simulations and showed how the capillary ridge height varies with other parameters, such as surface tension coefficient, inclination angle, initial thickness, and power-law parameters. As shown in our results, we found that capillary ridge height increased with higher surface tension, steeper inclination angle, bigger initial thickness, and more Newtonian fluids. This study provides the initial insights of how to optimize the flow and prevent the appearance of a capillary ridge and fingering instability. PMID:23687391
The effect of different power outputs of carbon dioxide laser on bonding between zirconia ceramic surface and resin cement.
Ural, CaĞri; KalyoncuoĞlu, Elif; Balkaya, Veysel
The purpose of this in vitro study was to evaluate the influence of different power outputs of a carbon dioxide (CO2) laser on shear bond strength of resin cement to zirconium dioxide-based ceramic. Fifty zirconium dioxide core specimens (10 mm diameter and 2 mm thickness) were produced and they were embedded in the centers of auto-polymerizing acrylic resin blocks. Ten specimens served as control and no surface treatment was applied. Subsequently specimens were randomly divided into four groups, each containing 10 specimens for surface treatment with CO2 laser with different output power; laser treated with 2 W (Group 2 W), 3 W (Group 3 W), 4 W (Group 4 W) and finally 5 W (Group 5 W). Fifty composite resin discs were fabricated and cemented with adhesive resin cement to the specimen surfaces. A universal test machine was used for shear bond strength test at a crosshead speed 1 mm/min. Data were statistically analyzed by one-way analyses of variance (ANOVA) with Post-Hoc Tukey tests (α = 0.05). It was found that the shear bond strength values were affected by power outputs of laser (p < 0.05). Highest shear bond strength values were obtained with group 2 W (21.0 ± 2.7). Lowest values were obtained with group 5 W (14.4 ± 1.6). The current study revealed that there was a relationship between laser output power and shear bond strength for zirconium dioxide ceramics. However, output power of the laser and the energy level is a critical factor on micromechanical retention.
Origin of Power Laws for Reactions at Metal Surfaces Mediated by Hot Electrons
DEFF Research Database (Denmark)
Olsen, Thomas; Schiøtz, Jakob
density functional theory and the delta self-consistent field method. With a simplifying assumption, the power law becomes exact and we obtain a simple physical interpretation of the exponent n, which represents the number of adsorbate vibrational states participating in the reaction....... of such experiments is the emergence of a power law dependence of the reaction yield on the laser fluence Y similar to F-n. We propose a model of multiple inelastic scattering by hot electrons which reproduces this power law and the observed exponents of several experiments. All parameters are calculated within...
Autonomus I&C Maintenance and Health Monitoring System for Fission Surface Power, Phase I
National Aeronautics and Space Administration — There currently exists no end-to-end reactor/power conversion monitoring system that can provide both autonomous health monitoring, but also in-situ sensor...
Autonomus I&C Maintenance and Health Monitoring System for Fission Surface Power, Phase II
National Aeronautics and Space Administration — The primary goal of this project is to design and develop an autonomous instrumentation and control (I&C) health monitoring system for space nuclear power...
Foulant Characteristics Comparison in Recycling Cooling Water System Makeup by Municipal Reclaimed Water and Surface Water in Power Plant
Ping, Xu; Jing, Wang; Yajun, Zhang; Jie, Wang; Shuai, Si
Due to water shortage, municipal reclaimed water rather than surface water was replenished into recycling cooling water system in power plants in some cities in China. In order to understand the effects of the measure on carbon steel corrosion, characteristics of two kinds of foulant produced in different systems were studied in the paper. Differences between municipal reclaimed water and surface water were analyzed firstly. Then, the weight and the morphology of two kinds of foulant were compared. Moreover, other characteristics including the total number of bacteria, sulfate reducing bacteria, iron bacteria, extracellular polymeric substance (EPS), protein (PN), and polysaccharide (PS) in foulant were analyzed. Based on results, it could be concluded that microbial and corrosive risk would be increased when the system replenished by municipal reclaimed water instead of surface water. PMID:25893132
Foulant Characteristics Comparison in Recycling Cooling Water System Makeup by Municipal Reclaimed Water and Surface Water in Power Plant
Directory of Open Access Journals (Sweden)
Xu Ping
Full Text Available Due to water shortage, municipal reclaimed water rather than surface water was replenished into recycling cooling water system in power plants in some cities in China. In order to understand the effects of the measure on carbon steel corrosion, characteristics of two kinds of foulant produced in different systems were studied in the paper. Differences between municipal reclaimed water and surface water were analyzed firstly. Then, the weight and the morphology of two kinds of foulant were compared. Moreover, other characteristics including the total number of bacteria, sulfate reducing bacteria, iron bacteria, extracellular polymeric substance (EPS, protein (PN, and polysaccharide (PS in foulant were analyzed. Based on results, it could be concluded that microbial and corrosive risk would be increased when the system replenished by municipal reclaimed water instead of surface water.
What is happening under the surface? Power, conflict and the performance of medical teams.
Janss, Rozemarijn; Rispens, Sonja; Segers, Mien; Jehn, Karen A
The effect of teamwork on team performance is broadly recognised in the medical field. This recognition is manifested in educational programmes in which attention to interpersonal behaviours during teamwork is growing. Conflict and power differences influence interpersonal behaviours and are marked topics in studies of group functioning in the social and organisational psychology literature. Insights from the domain of social sciences put the ongoing improvement of teamwork into broader perspective. This paper shows how knowledge from the domain of social and organisational psychology contributes to the understanding of teamwork in the medical environment. More specifically, this paper suggests that unfolding the underlying issues of power and conflict within medical teams can be of extra help in the development of educational interventions aimed at improving team performance. We review the key social psychology and organisational behaviour literature concerning power and conflict, and relate the insights derived from this to the team process of ad hoc medical action teams. We present a theoretical framework in which insights into power and conflict are used to explain and predict team dynamics in ad hoc medical action teams. Power and conflict strongly influence interpersonal behaviour. Characteristics of medical action teams give rise to all kinds of issues of disagreement and are accompanied by complex issues of intra-team power distribution. We argue that how team members coordinate, cooperate and communicate is steered by members' personal motivations, which, in turn, strongly depend on their perceptions of power and conflict. Given the importance of the performance of these teams, we suggest future directions for the development of training interventions building on knowledge and theories derived from social and organisational psychology. © Blackwell Publishing Ltd 2012.
Characterization of the inside and outside oxide surfaces of irradiated pressure tubes of Embalse nuclear power plant
International Nuclear Information System (INIS)
Bordoni, Roberto A.; Olmedo, Ana M.
The inside and outside surfaces of two pressure tubes (PT) removed from Embalse nuclear power plant (CNE) after 10 of effective full power years (EFPY) were characterized. The oxide thickness of both faces, in different zones, was also measured. The inside surfaces of both PTs, B-102 (A-14) and B-298 (L-12), were covered with a black oxide that replicates the original PT surface. A network of microcracks perpendicular to the inside surface in contact with the coolant was found. In some cases, near the outlet of the PT, some spalling of the oxide was also found. These small microcracks and spalling do not affect the protective character of the oxide since a thickness about 5 or 6 μm of an undamaged oxide is found at the metal/oxide interface side. The oxide thickness changes between approximately 6 to 12 μm for B-102 tube and around 7 to 15 μm for B-298 tube. The average corrosion rate is 1.16 μm/10 4 HH for B-102 tube and 1.35 μm/10 4 HH for B-298 tube at 5.8 m position for both PTs. These corrosion rates show good corrosion behaviour of CNE PTs. The average corrosion rate of the inside surface of the PTs depends on the coolant temperature but not on fast neutron flux. The outside oxide film is black, shiny, compact and protective, replicating also the original surface. The oxide thickness changes between 2 to 6.5 μm in B-102 tube and between 1.8 to 3.7 μm B-298 tube. These oxide thicknesses are within the values reported for PTs in CANDU Stations. (author) [es
Thermal and Physical Properties and Deposit Structure of Power Equipment Heating Surfaces
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A. V. Nerezko
Full Text Available The paper shows influence of heating surface material, design peculiarities, operational conditions of heat exchangers and water-chemical regime on chemical and structural composition of deposits, their heat conduction and porosity.
Dust generation mechanisms under powerful plasma impacts to the tungsten surfaces in ITER ELM simulation experiments
International Nuclear Information System (INIS)
Makhlaj, V.A.; Garkusha, I.E.; Aksenov, N.N.; Chuvilo, A.A.; Chebotarev, V.V.; Landman, I.; Malykhin, S.V.; Pestchanyi, S.; Pugachov, A.T.
In recent tokamak simulation experiments with the QSPA Kh-50 facility several mechanisms of dust generation from tungsten surfaces under ITER ELM-like energy loads have been identified. Here cracking and melting are reported. The brittle destruction dominates after a few transient impacts when a network of major cracks forms on the surface. Bifurcation of major cracks results in ejection of dust particles with sizes up to ∼30 μm. Dust generation occurs also after surface melting and following resolidification when fine crack networks along the grain boundaries develop. In this process the destruction is accompanied by bridge formation due to capillary tension across the fine cracks. Next impacts (even weak melt-free ones) can destroy those bridges, which produces considerable amounts of dust particles of nm-size dust. Surface modification after the repetitive plasma pulses also results in creation of nm-size dust
Directory of Open Access Journals (Sweden)
Rania Fathy
Full Text Available The analysis of laminar boundary layer flow and heat transfer of non-Newtonian fluids over a continuous stretched surface with suction or injection has been presented.The velocity and temperature of the sheet were assumed to vary in a power-law form, that is u = U0xm, and Tw(x = T+ Cxb. The viscosity of the fluid is assumed to be inverse linear function of temperature. The resulting governing boundary-layer equations are highly non-linear and coupled form of partial differential equations and they have been solved numerically by using the Runge-Kutta method and Shooting technique. Velocity and temperature distributions as well as the Nusselt number where studied for two thermal boundary conditions: uniform surface temperature (b = 0 and cooled surface temperature (b = -1, for different parameters: variable viscosity parameter qr, temperature exponent b, blowing parameter d and Prandtl number. The obtained results show that the flow and heat transfer characteristics are significantly influenced by these parameters.
Local digital control of power electronic converters in a dc microgrid based on a-priori derivation of switching surfaces
Banerjee, Bibaswan
In power electronic basedmicrogrids, the computational requirements needed to implement an optimized online control strategy can be prohibitive. The work presented in this dissertation proposes a generalized method of derivation of geometric manifolds in a dc microgrid that is based on the a-priori computation of the optimal reactions and trajectories for classes of events in a dc microgrid. The proposed states are the stored energies in all the energy storage elements of the dc microgrid and power flowing into them. It is anticipated that calculating a large enough set of dissimilar transient scenarios will also span many scenarios not specifically used to develop the surface. These geometric manifolds will then be used as reference surfaces in any type of controller, such as a sliding mode hysteretic controller. The presence of switched power converters in microgrids involve different control actions for different system events. The control of the switch states of the converters is essential for steady state and transient operations. A digital memory look-up based controller that uses a hysteretic sliding mode control strategy is an effective technique to generate the proper switch states for the converters. An example dcmicrogrid with three dc-dc boost converters and resistive loads is considered for this work. The geometric manifolds are successfully generated for transient events, such as step changes in the loads and the sources. The surfaces corresponding to a specific case of step change in the loads are then used as reference surfaces in an EEPROM for experimentally validating the control strategy. The required switch states corresponding to this specific transient scenario are programmed in the EEPROM as a memory table. This controls the switching of the dc-dc boost converters and drives the system states to the reference manifold. In this work, it is shown that this strategy effectively controls the system for a transient condition such as step changes
Microscale anechoic architecture: acoustic diffusers for ultra low power microparticle separation via traveling surface acoustic waves.
Behrens, Jan; Langelier, Sean; Rezk, Amgad R; Lindner, Gerhard; Yeo, Leslie Y; Friend, James R
We present a versatile and very low-power traveling SAW microfluidic sorting device able to displace and separate particles of different diameter in aqueous suspension; the travelling wave propagates through the fluid bulk and diffuses via a Schröder diffuser, adapted from its typical use in concert hall acoustics to be the smallest such diffuser to be suitable for microfluidics. The effective operating power range is two to three orders of magnitude less than current SAW devices, uniquely eliminating the need for amplifiers, and by using traveling waves to impart forces directly upon suspended microparticles, they can be separated by size.
Transient stability and control of wind turbine generation based on Hamiltonian surface shaping and power flow control
Energy Technology Data Exchange (ETDEWEB)
Wilson, David G.; Robinett, Rush D. III [Sandia National Laboratories, Albuquerque, NM (United States). Energy, Resources and Systems Analysis Center
The swing equations for renewable generators connected to the grid are developed and a simple wind turbine with UPFC is used as an example. The swing equations for renewable generator are formulated as a natural Hamiltonian system with externally applied non-conservative forces. A two-step process referred to as Hamiltonian Surface Shaping and Power Flow Control (HSSPFC) is used to analyze and design feedback controllers for the renewable generators system. This formulation extends previous results on the analytical verification of the Potential Energy Boundary Surface (PEBS) method to nonlinear control analysis and design and justifies the decomposition of the system into conservative and nonconservative systems to enable a two-step, serial analysis and design procedure. This paper presents the analysis and numerical simulation results for a nonlinear control design example that includes the One-Machine Infinite Bus (OMIB) system with a Unified Power Flow Control (UPEC) and applied to a simplified wind turbine generator. The needed power and energy storage/charging responses are also determined. (orig.)
Verification of surface contamination density standard using clearance automatic laser inspection system for objects from a nuclear power plant
International Nuclear Information System (INIS)
Sasaki, Michiya; Ogino, Haruyuki; Ichiji, Takeshi; Hattori, Takatoshi
In the clearance level inspection in Japan, it is necessary to indicate that the activity level of the target object must be less than not only the clearance levels, but also the surface contamination density standards. The classification measurements for these two standards have been performed separately, and the GM survey meters based on beta-ray measurement have mainly been used for surface contamination density measurement so far. Recently the Clearance Automatic Laser Inspection System, named CLALIS, has been developed to estimate the low-level activity concentration. This system consists of 3-dimensional laser scanner for shape measurement and eight large NE102A plastic scintillation detectors for gamma-ray measurement, and it has been clarified that the CLALIS has adequate detection ability for clearance measurement of both metal scraps and concrete debris. In this study, we compared the surface contamination densities for a number of actual contaminated and non-contaminated objects generated inside from the radiation controlled area at the Kashiwazaki-Kariwa nuclear power station by using the CLALIS and the GM survey meter. As a result, since CLALIS could detect the surface contamination as well as the GM survey meter for all measurement targets, it was revealed that CLALIS can rationally achieve clearance level inspection in a single radiation measurement. The practicality of CLALIS in view of the detection limit and processing time was discussed by comparison with the usual radiation monitors for surface contamination measurement. (author)
Graphite anode surface modification with controlled reduction of specific aryl diazonium salts for improved microbial fuel cells power output.
Picot, Matthieu; Lapinsonnière, Laure; Rothballer, Michael; Barrière, Frédéric
Graphite electrodes were modified with reduction of aryl diazonium salts and implemented as anodes in microbial fuel cells. First, reduction of 4-aminophenyl diazonium is considered using increased coulombic charge density from 16.5 to 200 mC/cm(2). This procedure introduced aryl amine functionalities at the surface which are neutral at neutral pH. These electrodes were implemented as anodes in "H" type microbial fuel cells inoculated with waste water, acetate as the substrate and using ferricyanide reduction at the cathode and a 1000 Ω external resistance. When the microbial anode had developed, the performances of the microbial fuel cells were measured under acetate saturation conditions and compared with those of control microbial fuel cells having an unmodified graphite anode. We found that the maximum power density of microbial fuel cell first increased as a function of the extent of modification, reaching an optimum after which it decreased for higher degree of surface modification, becoming even less performing than the control microbial fuel cell. Then, the effect of the introduction of charged groups at the surface was investigated at a low degree of surface modification. It was found that negatively charged groups at the surface (carboxylate) decreased microbial fuel cell power output while the introduction of positively charged groups doubled the power output. Scanning electron microscopy revealed that the microbial anode modified with positively charged groups was covered by a dense and homogeneous biofilm. Fluorescence in situ hybridization analyses showed that this biofilm consisted to a large extent of bacteria from the known electroactive Geobacter genus. In summary, the extent of modification of the anode was found to be critical for the microbial fuel cell performance. The nature of the chemical group introduced at the electrode surface was also found to significantly affect the performance of the microbial fuel cells. The method used for
Mirror and grating surface figure requirements for grazing incidence synchrotron radiation beamlines: Power loading effects
Energy Technology Data Exchange (ETDEWEB)
Hulbert, S.L.; Sharma, S.
At present, grazing incidence mirrors are used almost exclusively as the first optical element in VUV and soft x-ray synchrotron radiation beamlines. The performance of these mirrors is determined by thermal and mechanical stress-induced figure errors as well as by figure errors remaining from the grinding and polishing process. With the advent of VUV and soft x-ray undulators and wigglers has come a new set of thermal stress problems related to both the magnitude and the spatial distribution of power from these devices. In many cases the power load on the entrance slits and gratings in these beamlines is no longer negligible. The dependence of thermally-induced front-end mirror figure errors on various storage ring and insertion device parameters (especially those at the National Synchrotron Light Source) and the effects of these figure errors on two classes of soft x-ray beamlines are presented.
Low Cost, Low Power, Passive Muon Telescope for Interrogating Martian Sub-Surface
Kedar, Sharon; Tanaka, Hirukui; Naudet, Charles; Plaut, Jeffrey J.; Jones, Cathleen E.; Webb, Frank H.
It has been demonstrated on Earth that a low power, passive muon detector can penetrate deep into geological structures up to several kilometers in size providing high density images of their interiors. Muon tomography is an entirely new class of planetary instrumentation that is ideally suited to address key areas in Mars Science, such as: the search for life and habitable environments, the distribution and state of water and ice and the level of geologic activity on Mars today.
An Investigation of the Effectiveness of Solar Power on Navy Surface Combatants
Figure 33. Comparison of a bare steel plate (left) with a steel plate with a solar array (right), using a "white hot" setting...is the stripping of ultraviolet light in the upper atmosphere by ozone. Other interactions occur, and by the time the sunlight reaches the Earth's...Delivering boost acceleration to automobiles in a process known as regenerative braking. • Serving as an uninterruptible power supply (UPS) to data
Surface treatment of dental implants with high- power pulsed ion beams
International Nuclear Information System (INIS)
Shulov, V.A.; Nochovnaya, N.A.; Remnev, G.E.; Ivanov, S.Y.; Lomakin, M.V.
The objective of the present research is development of HPPIB technology for surface processing of compact components with a complex shape. The surface state of the dental implants from titanium alloys before and after irradiation and long time operation was investigated by Auger electron spectroscopy, scanning electron microscopy, X-ray structural analysis, optical metallography methods. It is shown that the homogeneous state in the surface layer of titanium alloys is formed due to the irradiation (carbon ions and protons, energy of ions is equal to 300 keV, density of ion energy in a pulse achieves 1-5 J/cm 2 ). This state is characterized by a low amount of the impurities and a fine dispersion structure formed as a result of high speed crystallization. Thus, HPPIB irradiation of the dental implants leads to formation of developed micro relief and the decrease of impurities content on the surface. As a result, this treatment allows one to achieve a good cohesion between the implants and a body tissue. The latter allows the conclusion that biocompatibility of the dental titanium implants produced by can be improved using HPPIB treatment
Surface modification of ceramic materials induced by irradiation of high power pulsed ICP
International Nuclear Information System (INIS)
Ishigaki, Takamasa; Okada, Nobuhiro; Ohashi, Naoki; Haneda, Hajime
Newly developed pulse-modulated high-power inductively coupled plasma [ICP] is expected to offer the unique physico-chemical condition, such as the increased concentration of chemically reactive species, as well as the appropriate heat flux for materials processing. Two kinds of oxide materials, titanium and zinc oxide, were placed at the downstream of Ar-H 2 ICP and irradiated in the plasma of continuous [CN] and pulse-modulated [PM] modes. The CN-ICP irradiation at the position close to the plasma tail gave rise to the thermal reduction of oxides. In the PM-ICP irradiation, the degree of thermal reduction depended on the lower power level during pulse-off time, as well as the total electric power. Irradiation in PM-ICP led to the increased formation of oxygen vacancies in titanium dioxide. In the case of zinc oxide, the UV emission efficiency was improved by PM-ICP irradiation, while the green emission became predominant by CN-ICP irradiation at the appropriate position. Induced effects in the two oxides by PM-ICP would be related to the high concentration of hydrogen radicals in the plasma. (author)
Infection of barley with the parasitic fungus Blumeria graminis f.sp. hordei results in the induction of HvADH1 and HvADH2.
Proels, Reinhard K; Westermeier, Wolfgang; Hückelhoven, Ralph
Besides the established functions of alcohol dehydrogenase (ADH) in the flooding response and in seed and pollen metabolism there is increasing evidence for a role of the fermentative pathway in biotic interactions. We have recently shown that barley ADH may be involved in susceptibility to the parasitic fungus Blumeria graminis f.sp. hordei (Bgh). Here, the transcriptional regulation of the barley ADH genes HvADH1 and HvADH2 after challenge of susceptible barley leaves with Bgh is addressed. Bgh infection results in an induction of HvADH1 and HvADH2, whereas HvADH3 expression was not detectable in leaves. With the use of native polyacrylamide gels the iso-enzyme composition with and without challenge by Bgh was analyzed, showing an activation of HvADH1 and HvADH2 in Bgh treated leaves.
Entropy Generation Analysis of Power-Law Non-Newtonian Fluid Flow Caused by Micropatterned Moving Surface
Directory of Open Access Journals (Sweden)
M. H. Yazdi
Full Text Available In the present study, the first and second law analyses of power-law non-Newtonian flow over embedded open parallel microchannels within micropatterned permeable continuous moving surface are examined at prescribed surface temperature. A similarity transformation is used to reduce the governing equations to a set of nonlinear ordinary differential equations. The dimensionless entropy generation number is formulated by an integral of the local rate of entropy generation along the width of the surface based on an equal number of microchannels and no-slip gaps interspersed between those microchannels. The velocity, the temperature, the velocity gradient, and the temperature gradient adjacent to the wall are substituted into this equation resulting from the momentum and energy equations obtained numerically by Dormand-Prince pair and shooting method. Finally, the entropy generation numbers, as well as the Bejan number, are evaluated. It is noted that the presence of the shear thinning (pseudoplastic fluids creates entropy along the surface, with an opposite effect resulting from shear thickening (dilatant fluids.
Cooptimization of Adhesion and Power Conversion Efficiency of Organic Solar Cells by Controlling Surface Energy of Buffer Layers.
Lee, Inhwa; Noh, Jonghyeon; Lee, Jung-Yong; Kim, Taek-Soo
Here, we demonstrate the cooptimization of the interfacial fracture energy and power conversion efficiency (PCE) of poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT)-based organic solar cells (OSCs) by surface treatments of the buffer layer. The investigated surface treatments of the buffer layer simultaneously changed the crack path and interfacial fracture energy of OSCs under mechanical stress and the work function of the buffer layer. To investigate the effects of surface treatments, the work of adhesion values were calculated and matched with the experimental results based on the Owens-Wendt model. Subsequently, we fabricated OSCs on surface-treated buffer layers. In particular, ZnO layers treated with poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) simultaneously satisfied the high mechanical reliability and PCE of OSCs by achieving high work of adhesion and optimized work function.
Comparative evaluation of hand and power-driven instruments on root surface characteristics: A scanning electron microscopy study
Directory of Open Access Journals (Sweden)
Parveen Dahiya
Full Text Available Aim: The aim of this study was to compare root surface characteristics following root planing with various hand- and power-driven instruments. Materials and Methods: A total of 20 single, rooted teeth were used in this study; two specimens were used as control (no instrumentation done and the remaining 18 specimens were equally divided into three groups. Specimens from each group were then subjected to root planing by one of the following instruments: (1 a Gracey curette, (2 ultrasonic tip and (3 a Rotary bur. In each case, the time required for scaling and root planing and surface roughness using the Roughness and Loss of Tooth Substance Index (RLTSI was measured. Result: The mean RLTSI scores for the Gracey curette, ultrasonic and rotary instrument groups were 2.5, 2.0 and 0.667, respectively. The mean scores of time spent for scaling and root planing by the Gracey curette, ultrasonic and rotary instrument groups in seconds were 42.50, 35.83 and 54.50, respectively. Conclusions: All the three instruments, namely Gracey curette, ultrasonic tip and rotary bur, were effective in mechanical debridement of the root surface. The results favored the use of rotary instruments for root planing to achieve a smooth, clean root surface; however, the use of rotary instrument was more time consuming, which might limit its use in clinical practice.
Experimental assessment of blade tip immersion depth from free surface on average power and thrust coefficients of marine current turbine
Lust, Ethan; Flack, Karen; Luznik, Luksa
Results from an experimental study on the effects of marine current turbine immersion depth from the free surface are presented. Measurements are performed with a 1/25 scale (diameter D = 0.8m) two bladed horizontal axis turbine towed in the large towing tank at the U.S. Naval Academy. Thrust and torque are measured using a dynamometer, mounted in line with the turbine shaft. Shaft rotation speed and blade position are measured using a shaft position indexing system. The tip speed ratio (TSR) is adjusted using a hysteresis brake which is attached to the output shaft. Two optical wave height sensors are used to measure the free surface elevation. The turbine is towed at 1.68 m/s, resulting in a 70% chord based Rec = 4 × 105. An Acoustic Doppler Velocimeter (ADV) is installed one turbine diameter upstream of the turbine rotation plane to characterize the inflow turbulence. Measurements are obtained at four relative blade tip immersion depths of z/D = 0.5, 0.4, 0.3, and 0.2 at a TSR value of 7 to identify the depth where free surface effects impact overall turbine performance. The overall average power and thrust coefficient are presented and compared to previously conducted baseline tests. The influence of wake expansion blockage on the turbine performance due to presence of the free surface at these immersion depths will also be discussed.
Energy Technology Data Exchange (ETDEWEB)
Hirshfield, Jay l
Results are reported on attempts to reduce the RF breakdown probability on copper accelerator structures by applying thin surface films that could suppress field emission of electrons. Techniques for application and testing of copper samples with films of metals with work functions higher than copper are described, principally for application of platinum films, since platinum has the second highest work function of any metal. Techniques for application of insulating films are also described, since these can suppress field emission and damage on account of dielectric shielding of fields at the copper surface, and on account of the greater hardness of insulating films, as compared with copper. In particular, application of zirconium oxide films on high-field portions of a 11.424 GHz SLAC cavity structure for breakdown tests are described.
Ozone production using a power modulated surface dielectric barrier discharge in dry synthetic air
Czech Academy of Sciences Publication Activity Database
Šimek, Milan; Pekárek, S.; Prukner, Václav
Roč. 32, č. 4 (2012), s. 743-754 ISSN 0272-4324 R&D Projects: GA ČR(CZ) GA202/09/0176 Institutional research plan: CEZ:AV0Z20430508 Keywords : ozone * surface DBD * synthetic air * nitrogen oxides * production efficiency Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.728, year: 2012 http://www.springerlink.com/content/h7p1j46381150510/fulltext. pdf
Influence of Power Modulation on Ozone Production Using an AC Surface Dielectric Barrier Discharge in Oxygen
Czech Academy of Sciences Publication Activity Database
Šimek, Milan; Pekárek, S.; Prukner, Václav
Roč. 30, č. 5 (2010), s. 607-617 ISSN 0272-4324 R&D Projects: GA ČR(CZ) GA202/09/0176 Institutional research plan: CEZ:AV0Z20430508 Keywords : Ozone * Surface DBD * Oxygen * Production efficiency Subject RIV: BL - Plasma and Gas Disc harge Physics Impact factor: 1.798, year: 2010 http://www.springerlink.com/content/28539775w5243513/
Distribution of the sea surface temperature in the area of the Angra dos Reis Power Plant: final report for missions 1,2 and 3
International Nuclear Information System (INIS)
Stevenson, M.R.; Inostrosa V, H.M.; Steffen, C.A.
This final report presents results from a cooperative study between CNPq/INPE and CNEN, to monitor spatial and temporal variations on sea surface temperature in the vicinity of Angra dos Reis power plant. (author)
Materials-of-Construction Radiation Sensitivity for a Fission Surface Power Convertor
Bowman, Cheryl L.; Geng, Steven M.; Niedra, Janis M.; Sayir, Ali; Shin, Eugene E.; Sutter, James K.; Thieme, Lanny G.
A fission reactor combined with a free-piston Stirling convertor is one of many credible approaches for producing electrical power in space applications. This study assumes dual-opposed free-piston Stirling engines/linear alternators that will operate nominally at 825 K hot-end and 425 K cold-end temperatures. The baseline design options, temperature profiles, and materials of construction discussed here are based on historical designs as well as modern convertors operating at lower power levels. This notional design indicates convertors primarily made of metallic components that experience minimal change in mechanical properties for fast neutron fluences less than 10(sup 20) neutrons per square centimeter. However, these radiation effects can impact the magnetic and electrical properties of metals at much lower fluences than are crucial for mechanical property integrity. Moreover, a variety of polymeric materials are also used in common free-piston Stirling designs for bonding, seals, lubrication, insulation and others. Polymers can be affected adversely by radiation doses as low as 10(sup 5) - 10(sup 10) rad. Additionally, the absorbing dose rate, radiation hardness, and the resulting effect (either hardening or softening) varies depending on the nature of the particular polymer. The classes of polymers currently used in convertor fabrication are discussed along possible substitution options. Thus, the materials of construction of prototypic Stirling convertor engines have been considered and the component materials susceptible to damage at the lowest neutron fluences have been identified.
Multi-objective optimization of surface roughness, cutting forces, productivity and Power consumption when turning of Inconel 718
Directory of Open Access Journals (Sweden)
Hamid Tebassi
Full Text Available Nickel based super alloys are excellent for several applications and mainly in structural components submitted to high temperatures owing to their high strength to weight ratio, good corrosion resistance and metallurgical stability such as in cases of jet engine and gas turbine components. The current work presents the experimental investigations of the cutting parameters effects (cutting speed, depth of cut and feed rate on the surface roughness, cutting force components, productivity and power consumption during dry conditions in straight turning using coated carbide tool. The mathematical models for output parameters have been developed using Box-Behnken design with 15 runs and Box-Cox transformation was used for improving normality. The results of the analysis have shown that the surface finish was statistically sensitive to the feed rate and cutting speed with the contribution of 43.58% and 23.85% respectively, while depth of cut had the greatest effect on the evolution of cutting force components with the contribution of 79.87% for feed force, 66.92% for radial force and 66.26% for tangential force. Multi-objective optimization procedure allowed minimizing roughness Ra, cutting forces and power consumption and maximizing material removal rate using desirability approach.
Testing external surface of fuel element tubes for power nuclear reactors
International Nuclear Information System (INIS)
Naugol'nykh, O.G.; Nelyubin, Yu.V.
Optical methods are regarded perspective for discovery and detection of flaws of external surfaces of fuel element tubes. The TV method has highest information content among them. Two mock-ups of facilities based on the TV method using a ''dissector'' type TV device and a TV tube with charge accumulation (vidikon) have been developed. It is concluded that complex testing - combination of ultrasonic, photoelectric and TV methods in a facility is necessary for discovery and analysis of the whole variety of flaws, though sensitivity of the TV method is enough for disclosure of all the main defects
Cleaning of inner surfaces and corrosion of secondary circuit of nuclear power plants
International Nuclear Information System (INIS)
Vilim, J.
Examples are shown of chemical cleaning procedures at the secondary circuit of WWER type reactors and at the Water Ford nuclear power plant. However, chemical cleaning has recently been abandoned for technical, economic and ecological reasons. Clean assembly is done followed by wash with water or a deionizator. The wash method used by Brown-Boveri is described. The problems are discussed of pipe passivation and of preservation for long periods between final cleaning and the actual heat start-up. Also discussed is the composition of the wash water and steam and of the material of tubes of the secondary circuit components, the steam generator and the condenser. (J.B.). 11 refs
Powerful near-surface geothermal energy with vertical groundwater circulation; Leistungsfaehige oberflaechennahe Geothermie mit vertikaler Grundwasserzirkulation
Energy Technology Data Exchange (ETDEWEB)
Viernickel, Michael [Geo-En Energy Technologies GmbH, Berlin (Germany). Bereich Produktentwicklung und Projektierung komplexer Energiesysteme unter Einsatz von Geothermie
The conversion of energy supply based on renewable energies will be electricity based and the efficient provision of heating and cooling can be done by electric heat pumps. In cities, however, where the open areas for geothermal systems are scarce, groundwater-based systems can be a powerful option. The development of a large heat reservoir via a single bore is possible with vertical groundwater circulation systems and is described here. [German] Der Umbau der Energieversorgung auf erneuerbare Energien wird Strom basiert sein und eine effiziente Bereitstellung von Waerme und Kaelte kann durch elektrische Waermepumpen erfolgen. Innerstaedtisch sind die Freiflaechen fuer Geothermieanlagen allerdings knapp, so dass Grundwasser basierte Anlagen eine leistungsfaehige Option darstellen koennen. Die Erschliessung eines grossen Waerme-Reservoirs ueber nur eine Bohrung ist mit vertikalen Grundwasserzirkulationsanlagen moeglich und wird hier beschrieben.
Nanofluids for power engineering: Emergency cooling of overheated heat transfer surfaces
Bondarenko, B. I.; Moraru, V. N.; Sidorenko, S. V.; Komysh, D. V.
The possibility of emergency cooling of an overheated heat transfer surface using nanofluids in the case of a boiling crisis is explored by means of synchronous recording of changes of main heat transfer parameters of boiling water over time. Two nanofluids are tested, which are derived from a mixture of natural aluminosilicates (AlSi-7) and titanium dioxide (NF-8). It is found that the introduction of a small portions of nanofluid into a boiling coolant (distilled water) in a state of film boiling ( t heater > 500°C) can dramatically decrease the heat transfer surface temperature to 130-150°C, which corresponds to a transition to a safe nucleate boiling regime without affecting the specific heat flux. The fact that this regime is kept for a long time at a specific heat load exceeding the critical heat flux for water and t heater = 125-130°C is particularly important. This makes it possible to prevent a potential accident emergency (heater burnout and failure of the heat exchanger) and to ensure the smooth operation of the equipment.
Single domain antibodies as a powerful tool for high quality surface plasmon resonance studies.
Directory of Open Access Journals (Sweden)
Eduardo Antonio Della Pia
Full Text Available Single domain antibodies are recombinantly expressed functional antibodies devoid of light chains. These binding elements are derived from heavy chain antibodies found in camelids and offer several distinctive properties for applications in biotechnology such as small size, stability, solubility, and expression in high yields. In this study we demonstrated the potential of using single domain antibodies as capturing molecules in biosensing applications. Single domain antibodies raised against green fluorescent protein were anchored onto biosensor surfaces by using several immobilization strategies based on Ni2+:nitrilotriacetic acid-polyhistidine tag, antibody-antigen, biotin-streptavidin interactions and amine-coupling chemistry. The interaction with the specific target of the single domain antibodies was characterized by surface plasmon resonance. The immobilized single domain antibodies show high affinities for their antigens with KD = 3-6 nM and outperform other antibody partners as capturing molecules facilitating also the data analysis. Furthermore they offer high resistance and stability to a wide range of denaturing agents. These unique biophysical properties and the production of novel single domain antibodies against affinity tags make them particularly attractive for use in biosensing and diagnostic assays.
Fabrication of Al5083/B4C surface composite by friction stir processing and its tribological characterization
Directory of Open Access Journals (Sweden)
Narayana Yuvaraj
Full Text Available Improved surface properties with the retainment of bulk properties are necessary for a component for enhanced wear characteristics. Friction stir processing (FSP is used to produce such surface composites. Fabrication of 5083 aluminum alloy with reinforced layers of boron carbide (B4C through FSP was carried out. Micro and nano sized B4C particles were used as reinforcements. The friction processed surface composite layer was analyzed through optical and scanning electron microscopical studies. The number of passes and the size of reinforcement play a vital role in the development of surface composites by FSP. Mechanical properties of the friction stir processed surface composites were evaluated through micro hardness and universal tensile tests. The results were compared with the properties of the base metal. The role of reinforcement and number of passes on properties were also evaluated. Tribological performance of the surface composites is tested through pin on disk test. The surface composite layer resulted in three passes with nano particle reinforcement exhibited better properties in hardness, tensile behavior and wear resistance compared to the behavior of the base metal.
Wind or water turbine power augmentation using the system of guiding surfaces
Bashurin, V. P.; Budnikov, I. N.; Hatunkin, V. Yu; Klevtsov, V. A.; Ktitorov, L. V.; Lazareva, A. S.; Meshkov, E. E.; Novikova, I. A.; Pletenev, F. A.; Yanbaev, G. M.
As fluid flows through a conventional wind or hydro turbine, it slows from losing energy to extraction from a turbine and spreads out to a wider area. This results in a loss of turbine efficiency. In order to exploit wind or water flow power more effectively, it was suggested to place the turbine inside a system of specially designed airfoils ('a flow booster'). One part of the booster ('a nozzle') improves the turbine performance by speeding up the flow acting on the turbine blades. The other part of the accelerating system ('a diffuser') creates a field of low pressure behind the turbine which helps to draw more mass flow to the turbine and avoid the loss of efficiency due to flow deceleration. The flow booster accumulates the kinetic energy of the flow (e.g. river flow or wind) in a small volume where the smaller turbine can be installed. Another possible application of the booster could be the improvement of wind turbine efficiency during low wind period. The present paper also discusses the possibility of kinetic energy accumulation by the use of several accelerating systems of different sizes—the smaller one can be installed inside the bigger one. It helps to accumulate even more kinetic energy on the turbine blades. We call this method the kinetic energy cumulation. Lab and field experiments and CFD simulations of shrouded turbine demonstrate significant increase in velocity in comparison of those for conventional (bare) turbines.
Wind or water turbine power augmentation using the system of guiding surfaces
International Nuclear Information System (INIS)
Bashurin, V P; Ktitorov, L V; Lazareva, A S; Pletenev, F A; Budnikov, I N; Hatunkin, V Yu; Klevtsov, V A; Meshkov, E E; Novikova, I A; Yanbaev, G M
As fluid flows through a conventional wind or hydro turbine, it slows from losing energy to extraction from a turbine and spreads out to a wider area. This results in a loss of turbine efficiency. In order to exploit wind or water flow power more effectively, it was suggested to place the turbine inside a system of specially designed airfoils ('a flow booster'). One part of the booster ('a nozzle') improves the turbine performance by speeding up the flow acting on the turbine blades. The other part of the accelerating system ('a diffuser') creates a field of low pressure behind the turbine which helps to draw more mass flow to the turbine and avoid the loss of efficiency due to flow deceleration. The flow booster accumulates the kinetic energy of the flow (e.g. river flow or wind) in a small volume where the smaller turbine can be installed. Another possible application of the booster could be the improvement of wind turbine efficiency during low wind period. The present paper also discusses the possibility of kinetic energy accumulation by the use of several accelerating systems of different sizes—the smaller one can be installed inside the bigger one. It helps to accumulate even more kinetic energy on the turbine blades. We call this method the kinetic energy cumulation. Lab and field experiments and CFD simulations of shrouded turbine demonstrate significant increase in velocity in comparison of those for conventional (bare) turbines. (paper)
Fast inspection of bulk and surface defects of large aperture optics in high power lasers
Zhao, Yuan'an; Hu, Guohang; Liu, Shijie; Yi, Kui; Shao, Jianda
Laser induced damage for nanosecond pulse duration is attributed to the existence of defects. The growth and polishing, as well as coating deposition, may induce versatile kinds of defects, including dig, scratch and inclusion. It is special important to get the information of the defects, such as size and location, which is the basis to know the origin of the defects and figures out effective techniques to eliminate it. It is quite easy to get the information of the defects with micron-level resolution, but it is time-consuming and is not suitable for fast inspection of the large aperture (hundreds of millimeters). In this work, on-the-fly image capture technique was employed to realize fast inspection of large aperture optics. A continuous green laser was employed as illumination source to enhance and enlarge the image of bulk defects. So it could detect the submicron-scale defects. A transmission microscopy with white light illumination was employed to detect the surface defect. Its field of view was about 2.8mm×1.6mm. The sample was raster scanned driving by a stepper motor through the stationary illumination laser and digital camera, and the speed to scan the sample was about 10mm/s. The results of large aperture optics proved the functions of this fast inspection technique.
Durability-enhanced two-dimensional hole gas of C-H diamond surface for complementary power inverter applications.
Kawarada, Hiroshi; Yamada, Tetsuya; Xu, Dechen; Tsuboi, Hidetoshi; Kitabayashi, Yuya; Matsumura, Daisuke; Shibata, Masanobu; Kudo, Takuya; Inaba, Masafumi; Hiraiwa, Atsushi
Complementary power field effect transistors (FETs) based on wide bandgap materials not only provide high-voltage switching capability with the reduction of on-resistance and switching losses, but also enable a smart inverter system by the dramatic simplification of external circuits. However, p-channel power FETs with equivalent performance to those of n-channel FETs are not obtained in any wide bandgap material other than diamond. Here we show that a breakdown voltage of more than 1600 V has been obtained in a diamond metal-oxide-semiconductor (MOS) FET with a p-channel based on a two-dimensional hole gas (2DHG). Atomic layer deposited (ALD) Al 2 O 3 induces the 2DHG ubiquitously on a hydrogen-terminated (C-H) diamond surface and also acts as both gate insulator and passivation layer. The high voltage performance is equivalent to that of state-of-the-art SiC planar n-channel FETs and AlGaN/GaN FETs. The drain current density in the on-state is also comparable to that of these two FETs with similar device size and V B .
Standard criteria for disposal of liquid radioactive wastes from nuclear power plants into surface waters (river systems)
International Nuclear Information System (INIS)
Pisarev, V.V.; Tsybizov, I.S.
Radioactive products discharge into natural water streams results in the necessity to regulate nuclear power plant discharges to ensure radiation safety (RS) for population using a river and surrounding river territory. To ensure RS it is necessary to set scientific-founded standards of permissible discharge level of liquid radioactive wastes (LRW) from nuclear power plant assuring observance of hygienic requirements for surface water puring. Volume of permissible LRW discharge into river systems must be set both with provision for concrete physical-geographycal conditions, specficity of utilizing the river and river valley and social-economical peculiarities of crtical population groups. The value of permissible LRW discharge into river systems is determined by three criterion groups: radiological, ecological and hydrological ones. By means of radiological group the internal and external irradiation doses for the whole body and its separate organs are set and RS of population is determined. Ecological criteria include a number of parameters (coefficients of accumulation, distribution and transition) determining quantitative ratios between radioactive element contents in water and separate links of biological chains: soil/water, fish/water, vegetables/water and others. Hydrological criteria determine the degree of waste dilution in rivers, control radioactive contamination of flood-lands areas and in common with ecological criteria determine radionuclide contents in soil and food products. A method of determining average annual values of LRW dilution in river waters is presented [ru
Adsorption Mechanism of Cu-Doped SnO2 (110 Surface toward H2 Dissolved in Power Transformer
Directory of Open Access Journals (Sweden)
Feng Wang
Full Text Available The content of hydrogen is a key quantity in condition assessment and fault diagnosis of power transformer. Based on the density functional theory (DFT, the adsorption mechanism of Cu-doped SnO2 surface toward H2 has been systematically studied in this work. Firstly, the relaxation, the bond length, and overlap population of both the pure and Cu-doped SnO2 are computed. To determine the optimal doping position, the formation energies of four potential sites (i.e., Sn5c, Sn6c, Sn5c-s, and Sn6c-s are then compared with each other. The adsorption energy and the electronic structure of SnO2 surface are analysed and discussed in detail. Furthermore, to estimate the partial atomic charges and the electrical conductance, the Mulliken population analysis is also performed. It has been found that the bridge oxygen is the most favourable position. The partial density of states of H2 after adsorption is broadened and shifted close to the Fermi level. A large amount of charges would be transferred and then released back into its conduction band, leading to the reduction of resistance and the enhancement of sensitivity toward H2. The results of this work provide references for SnO2-based sensor design.
Aperfeiçoamento da técnica de Soldagem Pontual por Fricção (FSpW) para união de poliamida 6 e laminado de poliamida 66 com fibra de carbono
Gonçalves, Joel; Santos, Jorge Fernandez dos; Canto, Leonardo Bresciani; Amancio Filho, Sergio de Traglia
A Soldagem Pontual por Fricção ('Friction Spot Welding - FSpW') é uma técnica inovadora que foi desenvolvida e patenteada em 2005 pelo centro de pesquisa alemão Helmholtz Zentrum Geesthacht (HZG). A técnica apresenta ciclos rápidos, baixo custo operacional e gera soldas com alto desempenho mecânico. Foi inicialmente projetada para a soldagem de ligas metálicas leves. A soldagem de polímeros é alvo de pesquisas recentes e a soldagem de compósitos poliméricos por FSpW ainda é inédita. Este estu...
Body Surface Contamination Levels of Residents under Different Evacuation Scenarios after the Fukushima Daiichi Nuclear Power Plant Accident.
Ohba, Takashi; Hasegawa, Arifumi; Kohayagawa, Yoshitaka; Kondo, Hisayoshi; Suzuki, Gen
Body surface contamination levels should be correlated with inhaled actual thyroid doses during evacuation following the Fukushima Daiichi nuclear power plant (FDNPP) accident. Evacuees and residents were screened for body surface contamination using a Geiger-Mueller survey meter. The authors obtained 7,539 individual screening data sheets as well as gamma-spectrometry data from measurements made on clothing of two subjects by using a germanium spectrometer. Body surface contamination levels were analyzed in four residential groups during two different periods: 12-14 and 15-17 March 2011. Contamination levels during 12-14 March in the Tomioka/Okuma/Futaba/Naraha group were very low, indicating that residents evacuated before the radioactive plume reached their towns on 12 March. In contrast, levels in the Namie and Minamisoma groups were higher than those in the other groups in both periods, indicating that these residents were exposed to plumes twice on 12 and 15-16 March. The plume on 12 March was enriched with short-lived radionuclides: averaged proportions of radioactivity (relative to I) from Te, I, and Cs measured in clothing from two subjects were 2.3, 1.1, and 0.1, respectively, after correction for physical decay by 12:00 on 12 March. These proportions are similar to those (relative to I) from Te and Cs in dust sampled by a high-volume air sampler in the zone 20 km from the FDNPP on 12 March: 1.9 and 0.1, respectively. These data indicate that the relative contribution to inhaled thyroid dose of short-lived radionuclides in radioactive plumes released on 12 March could be as much as 37.5% in 1-y-old children.
Development of a Thin Film Primary Surface Heat Exchanger for Advanced Power Cycles
Energy Technology Data Exchange (ETDEWEB)
Allison, Tim [Southwest Research Inst., San Antonio, TX (United States); Beck, Griffin [Southwest Research Inst., San Antonio, TX (United States); Bennett, Jeffrey [Southwest Research Inst., San Antonio, TX (United States); Hoopes, Kevin [Southwest Research Inst., San Antonio, TX (United States); Miller, Larry [Southwest Research Inst., San Antonio, TX (United States)
This project objective is to develop a high-temperature design upgrade for an existing primary surface heat exchanger so that the redesigned hardware is capable of operation in CO2 at temperatures up to 1,510°F (821°C) and pressure differentials up to 130 psi (9 bar). The heat exchanger is proposed for use as a recuperator in an advanced low-pressure oxy-fuel Brayton cycle that is predicted to achieve over 50% thermodynamic efficiency, although the heat exchanger could also be used in other high-temperature, low-differential pressure cycles. This report describes the progress to date, which includes continuing work performed to select and test new candidate materials for the recuperator redesign, final mechanical and thermal performance analysis results of various redesign concepts, and the preliminary design of a test loop for the redesigned recuperator including a budgetary estimate for detailed test loop design, procurement, and test operation. A materials search was performed in order to investigate high-temperature properties of many candidate materials, including high-temperature strength and nickel content. These properties were used to rank the candidate materials, resulting in a reduced list of nine materials for corrosion testing. Multiple test rigs were considered and analyzed for short-term corrosion testing and Thermal Gravimetric Analysis (TGA) was selected as the most cost-effective option for evaluating corrosion resistance of the candidate materials. In addition, tantalum, niobium, and chromium coatings were identified as potential options for increased corrosion resistance. The test results show that many materials exhibit relatively low weight gain rates, and that niobium and tantalum coatings may improve corrosion resistance for many materials, while chromium coatings appear to oxidize and debond quickly. Metallurgical analysis of alloys was also performed, showing evidence of intergranular attack in 282 that may cause long
Behavior of a thermoelectric power generation device based on solar irradiation and the earth's surface-air temperature difference
International Nuclear Information System (INIS)
Zhang, Zhe; Li, Wenbin; Kan, Jiangming
Highlights: • A technical solution to the power supply of wireless sensor networks is presented. • The low voltage produced by TEG is boosted from less than 1 V to more than 4 V. • An output current and voltage of TEG device is acquired as 21.47 mA and 221 mV. • The device successfully provides output power 4.7 mW in no electricity conditions. • The thermo-economic value of TEG device is demonstrated. - Abstract: Motivated by the limited power supply of wireless sensors used to monitor the natural environment, for example, in forests, this study presents a technical solution by recycling solar irradiation heat using thermoelectric generators. Based on solar irradiation and the earth's surface-air temperature difference, a new type of thermoelectric power generation device has been devised, the distinguishing features of which include the application of an all-glass heat-tube-type vacuum solar heat collection pipe to absorb and transfer solar energy without a water medium and the use of a thin heat dissipation tube to cool the earth surface air temperature. The effects of key parameters such as solar illumination, air temperature, load resistance, the proportional coefficient, output power and power generation efficiency for thermoelectric energy conversion are analyzed. The results of realistic outdoor experiments show that under a state of regular illumination at 3.75 × 10 4 lx, using one TEG module, the thermoelectric device is able to boost the voltage obtained from the natural solar irradiation from 221 mV to 4.41 V, with an output power of 4.7 mW. This means that the electrical energy generated can provide the power supply for low power consumption components, such as low power wireless sensors, ZigBee modules and other low power loads
Elongation of gold nanoparticles by swift heavy ion irradiation: Surface plasmon resonance shift dependence on the electronic stopping power
International Nuclear Information System (INIS)
Kerboua, C. Harkati; Lamarre, J.-M.; Chicoine, M.; Martinu, L.; Roorda, S.
Gold nanoparticles embedded in a silica matrix were irradiated with 2 to 40 MeV Cu or Si ions at fluences ranging from 1 × 10 13 to 4 × 10 15 ions/cm 2 , and their deformation from spheres to prolate ellipsoids with major axis parallel to the ion beam was studied using P and S polarized light. For fixed ion energy, the longitudinal surface plasmon resonance (SPR) at 520 nm is red-shifted with an increase of the ion fluence up to a certain value where it reaches a plateau indicating that a maximum aspect ratio is obtained. This saturation in the wavelength shift was found to depend on the ion energy and reaches a maximum of 40 nm. The SPR shift was also used to measure the electronic stopping power dependent deformation rate and to deduce the electronic stopping power threshold of (1.9 ± 1.3) keV/nm required for shape transformation of the embedded gold nanoparticles. Ion track diameters of 0.18 to 1.4 nm were inferred from the fluence dependence of the SPR shift. Analysis by transmission electron microscopy shows that large (d > 10 nm) particles are more elongated than smaller ones. Our data are consistent with a mechanism of gold nanoparticle elongation requiring both the silica matrix and the nanoparticles to melt following the passage of the swift heavy ion and with elongation being due to the relief of stress in the gold nanoparticle which had built up as a consequence of the deformation of the surrounding silica matrix. - Highlights: ► We irradiated gold nanoparticles embedded in silica with swift heavy ions. ► Such treatment changes the shape of the particles, from spherical to nano-rods. ► Irradiation of the silica matrix leads to anisotropic growth, so-called hammering. ► Stress applied by the deformed silica onto the gold nanoparticles deforms them
New Geographical Insights of the Latest Expansion of Fusarium oxysporum f.sp. cubense Tropical Race 4 Into the Greater Mekong Subregion
Directory of Open Access Journals (Sweden)
Si-Jun Zheng
Full Text Available Banana is the most popular and most exported fruit and also a major food crop for millions of people around the world. Despite its importance and the presence of serious disease threats, research into this crop is limited. One of those is Panama disease or Fusarium wilt. In the previous century Fusarium wilt wiped out the "Gros Michel" based banana industry in Central America. The epidemic was eventually quenched by planting "Cavendish" bananas. However, 50 years ago the disease recurred, but now on "Cavendish" bananas. Since then the disease has spread across South-East Asia, to the Middle-East and the Indian subcontinent and leaped into Africa. Here, we report the presence of Fusarium oxysporum f.sp. cubense Tropical Race 4 (Foc TR4 in "Cavendish" plantations in Laos, Myanmar, and Vietnam. A combination of classical morphology, DNA sequencing, and phenotyping assays revealed a very close relationship between the Foc TR4 strains in the entire Greater Mekong Subregion (GMS, which is increasingly prone to intensive banana production. Analyses of single-nucleotide polymorphisms enabled us to initiate a phylogeography of Foc TR4 across three geographical areas—GMS, Indian subcontinent, and the Middle East revealing three distinct Foc TR4 sub-lineages. Collectively, our data place these new incursions in a broader agroecological context and underscore the need for awareness campaigns and the implementation of validated quarantine measures to prevent further international dissemination of Foc TR4.
Fusarium oxysporum f.sp. ciceri race 1 induced redox state alterations are coupled to downstream defense signaling in root tissues of chickpea (Cicer arietinum L..
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Sumanti Gupta
Full Text Available Reactive oxygen species are known to play pivotal roles in pathogen perception, recognition and downstream defense signaling. But, how these redox alarms coordinate in planta into a defensive network is still intangible. Present study illustrates the role of Fusarium oxysporum f.sp ciceri Race1 (Foc1 induced redox responsive transcripts in regulating downstream defense signaling in chickpea. Confocal microscopic studies highlighted pathogen invasion and colonization accompanied by tissue damage and deposition of callose degraded products at the xylem vessels of infected roots of chickpea plants. Such depositions led to the clogging of xylem vessels in compatible hosts while the resistant plants were devoid of such obstructions. Lipid peroxidation assays also indicated fungal induced membrane injury. Cell shrinkage and gradual nuclear adpression appeared as interesting features marking fungal ingress. Quantitative real time polymerase chain reaction exhibited differential expression patterns of redox regulators, cellular transporters and transcription factors during Foc1 progression. Network analysis showed redox regulators, cellular transporters and transcription factors to coordinate into a well orchestrated defensive network with sugars acting as internal signal modulators. Respiratory burst oxidase homologue, cationic peroxidase, vacuolar sorting receptor, polyol transporter, sucrose synthase, and zinc finger domain containing transcription factor appeared as key molecular candidates controlling important hubs of the defense network. Functional characterization of these hub controllers may prove to be promising in understanding chickpea-Foc1 interaction and developing the case study as a model for looking into the complexities of wilt diseases of other important crop legumes.
Barley susceptibility factor RACB modulates transcript levels of signalling protein genes in compatible interaction with Blumeria graminis f.sp. hordei.
Schnepf, Vera; Vlot, A Corina; Kugler, Karl; Hückelhoven, Ralph
RHO (rat sarcoma homologue) GTPases (guanosine triphosphatases) are regulators of downstream transcriptional responses of eukaryotes to intracellular and extracellular stimuli. For plants, little is known about the function of Rho-like GTPases [called RACs (rat sarcoma-related C botulinum substrate) or ROPs (RHO of plants)] in transcriptional reprogramming of cells. However, in plant hormone response and innate immunity, RAC/ROP proteins influence gene expression patterns. The barley RAC/ROP RACB is required for full susceptibility of barley to the powdery mildew fungus Blumeria graminis f.sp. hordei (Bgh). We compared the transcriptomes of barley plants either silenced for RACB or over-expressing constitutively activated RACB with and without inoculation with Bgh. This revealed a large overlap of the barley transcriptome during the early response to Bgh and during the over-expression of constitutively activated RACB. Global pathway analyses and stringent analyses of differentially expressed genes suggested that RACB influences, amongst others, the expression of signalling receptor kinases. Transient induced gene silencing of RACB-regulated signalling genes (a leucine-rich repeat protein, a leucine-rich repeat receptor-like kinase and an S-domain SD1-receptor-like kinase) suggested that they might be involved in RACB-modulated susceptibility to powdery mildew. We discuss the function of RACB in regulating the transcriptional responses of susceptible barley to Bgh. © 2016 BSPP AND JOHN WILEY & SONS LTD.
p-Coumaric acid influenced cucumber rhizosphere soil microbial communities and the growth of Fusarium oxysporum f.sp. cucumerinum Owen.
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Xingang Zhou
Full Text Available BACKGROUND: Autotoxicity of cucumber root exudates or decaying residues may be the cause of the soil sickness of cucumber. However, how autotoxins affect soil microbial communities is not yet fully understood. METHODOLOGY/PRINCIPAL FINDINGS: The aims of this study were to study the effects of an artificially applied autotoxin of cucumber, p-coumaric acid, on cucumber seedling growth, rhizosphere soil microbial communities, and Fusarium oxysporum f.sp. cucumerinum Owen (a soil-borne pathogen of cucumber growth. Abundance, structure and composition of rhizosphere bacterial and fungal communities were analyzed with real-time PCR, PCR-denaturing gradient gel electrophoresis (DGGE and clone library methods. Soil dehydrogenase activity and microbial biomass C (MBC were determined to indicate the activity and size of the soil microflora. Results showed that p-coumaric acid (0.1-1.0 µmol/g soil decreased cucumber leaf area, and increased soil dehydrogenase activity, MBC and rhizosphere bacterial and fungal community abundances. p-Coumaric acid also changed the structure and composition of rhizosphere bacterial and fungal communities, with increases in the relative abundances of bacterial taxa Firmicutes, Betaproteobacteria, Gammaproteobacteria and fungal taxa Sordariomycete, Zygomycota, and decreases in the relative abundances of bacterial taxa Bacteroidetes, Deltaproteobacteria, Planctomycetes, Verrucomicrobia and fungal taxon Pezizomycete. In addition, p-coumaric acid increased Fusarium oxysporum population densities in soil. CONCLUSIONS/SIGNIFICANCE: These results indicate that p-coumaric acid may play a role in the autotoxicity of cucumber via influencing soil microbial communities.
Dynamics of Colonization and Expression of Pathogenicity Related Genes in Fusarium oxysporum f.sp. ciceri during Chickpea Vascular Wilt Disease Progression.
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Medha L Upasani
Full Text Available Fusarium wilt caused by Fusarium oxysporum f.sp. ciceri (Foc is a constant threat to chickpea productivity in several parts of the world. Understanding the molecular basis of chickpea-Foc interaction is necessary to improve chickpea resistance to Foc and thereby the productivity of chickpea. We transformed Foc race 2 using green fluorescent protein (GFP gene and used it to characterize pathogen progression and colonization in wilt-susceptible (JG62 and wilt-resistant (Digvijay chickpea cultivars using confocal microscopy. We also employed quantitative PCR (qPCR to estimate the pathogen load and progression across various tissues of both the chickpea cultivars during the course of the disease. Additionally, the expression of several candidate pathogen virulence genes was analyzed using quantitative reverse transcriptase PCR (qRT-PCR, which showed their characteristic expression in wilt-susceptible and resistant chickpea cultivars. Our results suggest that the pathogen colonizes the susceptible cultivar defeating its defense; however, albeit its entry in the resistant plant, further proliferation is severely restricted providing an evidence of efficient defense mechanism in the resistant chickpea cultivar.
A rapid genotyping method for an obligate fungal pathogen, Puccinia striiformis f.sp. tritici, based on DNA extraction from infected leaf and Multiplex PCR genotyping
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Enjalbert Jérôme
Full Text Available Abstract Background Puccinia striiformis f.sp. tritici (PST, an obligate fungal pathogen causing wheat yellow/stripe rust, a serious disease, has been used to understand the evolution of crop pathogen using molecular markers. However, numerous questions regarding its evolutionary history and recent migration routes still remains to be addressed, which need the genotyping of a large number of isolates, a process that is limited by both DNA extraction and genotyping methods. To address the two issues, we developed here a method for direct DNA extraction from infected leaves combined with optimized SSR multiplexing. Findings We report here an efficient protocol for direct fungal DNA extraction from infected leaves, avoiding the costly and time consuming step of spore multiplication. The genotyping strategy we propose, amplified a total of 20 SSRs in three Multiplex PCR reactions, which were highly polymorphic and were able to differentiate different PST populations with high efficiency and accuracy. Conclusion These two developments enabled a genotyping strategy that could contribute to the development of molecular epidemiology of yellow rust disease, both at a regional or worldwide scale.
Hardness, microstructure and surface characterization of laser gas nitrided commercially pure titanium using high power CO{sub 2} laser
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Selvan, J.S.; Subramanian, K. [Anna Univ., Chennai (India). Dept. of Physics; Nath, A.K. [Center for Advanced Technology, Madya Pradesh (India); Gogia, A.K. [DMRL, Hyderabad (India); Balamurugan, A.K.; Rajagopal, S. [Indira Gandhi Centre for Atomic Research, Tamil Nadu (India). Materials Science Div.
Surface nitriding of commercially pure (CP) titanium was carried out using high power CO{sub 2} laser at pure nitrogen and dilute nitrogen (N{sub 2} + Ar) environment. The hardness, microstructure, and melt pool configuration of the laser melted titanium in helium and argon atmosphere was compared with laser melting at pure and dilute nitrogen environment. The hardness of the nitrided layer was of the order of 1000 to 1600 HV. The hardness of the laser melted titanium in the argon and helium atmosphere was 500 to 1000 HV. Using x-ray analysis of the formation of TiN and Ti{sub 2}N phase was identified in the laser nitrided titanium. The presence of nitrogen in the nitrided zone was confirmed using secondary ion mass spectroscopy (SIMS) analysis. The microstructures revealed densely populated dendrites in the sample nitrided at 100% N{sub 2} environment and thinly populated dendrites in dilute environment. The crack intensity was large in the nitrided sample at pure nitrogen, and few cracks were observed in the 50% N{sub 2} + 50% Ar environment.
Separation of surface, subsurface and volume fatigue damage effects in AISI 348 steel for power plant applications
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Klein, Martin; Nowak, David; Walther, Frank [Technical Univ. Dortmund (Germany). Dept. of Materials Test Engineering (WPT); Starke, Peter [Saarland Univ., Saarbruecken (Germany). Chair of Non-Destructive Testing and Quality Assurance; Boller, Christian [Saarland Univ., Saarbruecken (Germany). Chair of Non-Destructive Testing and Quality Assurance; Fraunhofer IZFP, Saarbruecken (Germany)
A wide range of industries including energy, chemistry, pharmacy, textiles, food and drink, pulp and paper, etc. is using stainless steels. Metastable austenitic steels such as used in power plants and chemical industry are subjected to cyclic mechanical and thermal loading in air as well as under the influence of corrosive media. This paper provides an overview on different nondestructive and electrochemical measurement techniques, which allow differentiating fatigue damage effects in total strain controlled multiple and constant amplitude tests with respect to damage appearance on surface, in subsurface area as well as in volume of specimens or components microstructure. In addition to conventional mechanical stress-strain hysteresis curves, electrical resistance, magnetic and open circuit potential measurements have been applied to characterize the cyclic deformation behavior of the metastable austenitic steel AISI 348 (X10CrNiNb18-9) in laboratory air and in distilled water. Based on these results obtained, the paper provides an outlook on the possibility for an efficient (remaining) fatigue life evaluation approach, which is adapted to the needs of the application areas.
Friction stir processed Al - Metal oxide surface composites: Anodization and optical appearance
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Gudla, Visweswara Chakravarthy; Jensen, Flemming; Canulescu, Stela
Multiple-pass friction stir processing (FSP) was employed to impregnate metal oxide (TiO2, Y2O3 and CeO2) particles into the surface of an Aluminium alloy. The surface composites were then anodized in a sulphuric acid electrolyte. The effect of anodizing parameters on the resulting optical...... appearance was studied. Microstructural and morphological characterization was performed using transmission electron microscopy (TEM). The surface appearance was analysed using an integrating sphere-spectrometer setup. Increasing the anodizing voltage changed the surface appearance of the composites from...
Thermal Pollution Mathematical Model. Volume 6; Verification of Three-Dimensional Free-Surface Model at Anclote Anchorage; [environment impact of thermal discharges from power plants
Lee, S. S.; Sengupta, S.; Tuann, S. Y.; Lee, C. R.
The free-surface model presented is for tidal estuaries and coastal regions where ambient tidal forces play an important role in the dispersal of heated water. The model is time dependent, three dimensional, and can handle irregular bottom topography. The vertical stretching coordinate is adopted for better treatment of kinematic condition at the water surface. The results include surface elevation, velocity, and temperature. The model was verified at the Anclote Anchorage site of Florida Power Company. Two data bases at four tidal stages for winter and summer conditions were used to verify the model. Differences between measured and predicted temperatures are on an average of less than 1 C.
Distribution of a pelagic tunicate, Salpa fusiformis in warm surface current of the eastern Korean waters and its impingement on cooling water intakes of Uljin nuclear power plant.
Chae, Jinho; Choi, Hyun Woo; Lee, Woo Jin; Kim, Dongsung; Lee, Jae Hac
Impingement of a large amount of gelatinous plankton, Salpa fusiformis on the seawater intake system-screens in a nuclear power plant at Uljin was firstly recorded on 18th June 2003. Whole amount of the clogged animals was estimated were presumptively at 295 tons and the shortage of cooling seawater supply by the animal clogging caused 38% of decrease in generation capability of the power plant. Zooplankton collection with a multiple towing net during the day and at night from 5 to 6 June 2003 included various gelatinous zooplanktons known to be warm water species such as salps and siphonophores. Comparatively larger species, Salpa fusiformis occupied 25.4% in individual density among the gelatinous plankton and showed surface distribution in the depth shallower than thermocline, performing little diel vertical migration. Temperature, salinity and satellite data also showed warm surface current predominated over the southern coastal region near the power plant in June. The results suggested that warm surface current occasionally extended into the neritic region may transfer S. fusiformis, to the waters off the power plant. The environmental factors and their relation to ecobiology of the large quantity of salpa population that are being sucked into the intake channel of the power plant are discussed.
Effects of surface shape on the geometry and surface topography of the melt pool in low-power density laser melting
Kim, Youngdeuk
The quantitative correlations between workpiece volume and melt pool geometry, as well as the flow and thermal features of the melt pool are established. Thermocapillary convections in melt pool with a deformable free surface are investigated with respect to surface shape and laser intensity. When the contact angle between the tangent to the top surface and the vertical wall at the hot center is acute, the free surface flattens, compared with that of the initial free surface. Otherwise, the free surface forms a bowl-like shape with a deep crater and a low peripheral rim when the contact angle at the hot center is obtuse. Increasing the workpiece volume at a fixed laser intensity and a negative radial height gradient cause linear decreases in the geometric size and magnitude of flow and temperature of the melt pool. Conversely, linear increases are observed with a positive radial height gradient. © 2011 American Institute of Chemical Engineers (AIChE).
Effect of surface microstructure and wettability on plasma protein adsorption to ZnO thin films prepared at different RF powers.
Huang, Zhan-Yun; Chen, Min; Pan, Shi-Rong; Chen, Di-Hu
In this paper, the adsorption behavior of plasma proteins on the surface of ZnO thin films prepared by radio frequency (RF) sputtering under different sputtering powers was studied. The microstructures and surface properties of the ZnO thin films were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible optical absorption spectroscopy and contact angle techniques. The results show that the ZnO thin films have better orientation of the (0 0 2) peak with increasing RF power, especially at around 160 W, and the optical band gap of the ZnO films varies from 3.2 to 3.4 eV. The contact angle test carried out by the sessile drop technique denoted a hydrophobic surface of the ZnO films, and the surface energy and adhesive work of the ZnO thin films decreased with increasing sputtering power. The amounts of human fibrinogen (HFG) and human serum albumin (HSA) adsorbing on the ZnO films and reference samples were determined by using enzyme-linked immunosorbent assay (ELISA). The results show that fewer plasma proteins and a smaller HFG/HSA ratio adsorb on the ZnO thin films' surface.
Uji Daya Hambat Jamur Endofit dan Eksofit dalam Menekan Pertumbuhan Fusarium oxysporum f.sp. vanillae Penyebab Busuk Batang Panili Secara In Vitro
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Full Text Available Study on In Vitro Inhibitory Ability of Endophytic and Exophytic Fungusin Suppressing the Growth of Fusarium oxysporum f.sp. vanillae thatCauses Stem Rot of Vanilla. Vanilla stem rot disease caused by Fusarium oxysporumf.sp. vanillae , is still a very dangerous disease and feared by vanilla farmers. Disease until thepresent time there does not yet appear adequate control strategies for the disease. On the basisof these problems interested studied the use of endophytic fungi and exophytic existing on theleaves and stems of healthy plants , which have potential as a biological agent to controlpathogens . The study was conducted in three stages: (1 isolation of the pathogen and fungalendophyte and exophytic, (2 identification of pathogenic microscopic morphology, fungalendophyte and exophytic, and (3 test the inhibition of fungal endophyte and exophyticagainst pathogens. Fungi are found as the leaves are Aspergillus niger and Rhizopus spp., Onexophytic on the trunk is Trichoderma sp . and Fusarium spp., as a leaf endophytic found A.niger and Neurospora spp. and as endophytic rod is Neurospora spp . The highest prevalenceachieved by Neurospora spp . which is equal to 100 % on endophyte stem, while Rhizopusspp., and Fusarium spp. by 90 % respectively, exophytic on the leaves and stems. The testresults found that the inhibition of leaf eksofit Rhisopus spp . give up inhibition ranged from70.37±3.2% - 100% , while A. niger amounted to 72.22% . In exophytic on rod found onlyTrichoderma sp. inhibit pathogens by 73.70±3.57%. In endophytic on leaf found A. niger at70.37±3.2% , while Neorospora spp. ranging from 79.11±3.21% - 88.50±2.10%. In theendophytic on trunk was found Neurosporas spp. amounting to 70.74±3.57% - 79.26±1.28%.
Deriving isolates of powdery mildew (Blumeria graminis DC. f.sp. avenae Em. Marchal. in common oat (Avena sativa L. and using them to identify selected resistance genes
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Sylwia Okoń
Full Text Available Powdery mildew in common oat is caused by Blumeria graminis DC. f.sp. avenae Em. Marchal. Host-pathogen tests are commonly used to identify and locate resistance genes to powdery mildew in cereals. The aim of the study was to determine the virulence of powdery mildew isolates obtained from powdery mildew populations harvested in Poland and to identify OMR1, OMR2 and OMR3 resistance genes to powdery mildew in F2 populations of inter-cultivar hybrids of common oat: Bruno × Fuchs, Jumbo × Fuchs and Mostyn × Fuchs. On the basis of the analysis conducted, isolates enabling division of the studied populations into groups of resistant and susceptible plants were selected. M10 and M14 isolates were chosen for the population which was obtained from crossbreeding of 'Bruno' with 'Fuchs'; these isolates demonstrated avirulence to Bruno cultivar containing OMR1 gene. In order to divide population obtained from crossbreeding of 'Jumbo' with 'Fuchs', M13 and M16 isolates were chosen; they demonstrated avirulence to the cultivar Jumbo containing the OMR2 gene. On the basis of the tests conducted, it was impossible to select isolates characterised by avirulence to the OMR3 gene. In the F2 population of Bruno × Fuchs and Jumbo × Fuchs hybrids, a division was made into resistant and susceptible plants. The obtained results were verified by the 2 test; the proportion in the dispersion matching model was found to be 3 resistant plants: 1 sensitive plant both in the Bruno × Fuchs and Jumbo × Fuchs populations. Such dispersion indicated that the resistance to powdery mildew in the studied cultivars Bruno and Jumbo was conditioned by single dominant genes.
Changes in lipid composition of Blumeria graminis f.sp. tritici conidia produced on wheat leaves treated with heptanoyl salicylic acid.
Muchembled, Jérôme; Sahraoui, Anissa Lounès-Hadj; Grandmougin-Ferjani, Anne; Sancholle, Michel
Treatment of wheat leaves with heptanoyl salicylic acid (HS) and trehalose at concentrations of 0.1 and 15 g l(-1), prior to fungal inoculation, resulted in 40% and 60% protection, respectively, against powdery mildew. The total lipid composition of Blumeria graminis f.sp. tritici (Bgt) conidia, the causal agent of wheat powdery mildew, was compared when produced on wheat leaves, respectively, untreated and treated with the two elicitors, HS and trehalose. An obvious effect was observed on lipid composition (sterol and fatty acid (FA)) of Bgt conidia produced on wheat leaves treated with HS. A total of 16 FA (C12-C24 saturated and unsaturated) as well as unusual methoxylated Fatty Acids (mFA) (3-methoxydocosanoic and 3-methoxytetracosanoic acids) were detected in the conidia. Medium chain FA were predominant in HS treated conidia (64.65%) while long chain fatty acids constituted the major compounds in untreated conidia (62%). The long chain/medium chain FA ratio decreased from 1.8 in the conidia produced on untreated leaves to 0.5 in the conidia obtained from HS treated leaves. When comparing the sterol composition of Bgt conidia produced on leaves treated with HS versus conidia obtained from untreated ones, very important changes within the two major classes can be seen. In particular, 24-methylsterols, e.g., 24-methylenecholesterol and 24-methylcholesta-7,24-dien were reduced by about 82% whereas 24-ethylsterols, e.g., 24-ethylcholesterol and 24-ethylcholesta-5,22-dienol were increased by about 85%. The 24-methylsterols/24-ethylsterols ratio was reduced by ninefold in the conidia produced from HS treated leaves.
Genetics of avirulence genes in Blumeria graminis f.sp. hordei and physical mapping of AVR(a22) and AVR(a12).
Skamnioti, Pari; Pedersen, Carsten; Al-Chaarani, Ghias R; Holefors, Anna; Thordal-Christensen, Hans; Brown, James K M; Ridout, Christopher J
Powdery mildew fungi are parasites that cause disease on a wide range of important crops. Plant resistance (R) genes, which induce host defences against powdery mildews, encode proteins that recognise avirulence (AVR) molecules from the parasite in a gene-for-gene manner. To gain insight into how virulence evolves in Blumeria graminis f.sp. hordei, associations between segregating AVR genes were established. As a prerequisite to the isolation of AVR genes, two loci were selected for further analysis. AVR(a22) is located in a tightly linked cluster comprising AVR(a10) and AVR(k1) as well as up to five other AVR genes. The ratio between physical and genetic distance in the cluster ranged between 0.7 and 35 kB/cM. The AVR(a22) locus was delimited by the previously isolated gene AVR(a10) and two cleaved amplified polymorphic sequence (CAPS) markers, 19H12R and 74E9L. By contrast, AVR(a12) was not linked to other AVR genes in two crosses. Bulk segregant analysis of over 100,000 AFLP fragments yielded two markers, ETAMTG-285 and PAAMACT-473, mapping 10 and 2cM from AVR(a12), respectively, thus delimiting AVR(a12) on one side. All markers obtained for AVR(a12) mapped proximal to it, indicating that the gene is located at the end of a chromosome. Three more AVR(a10) paralogues were identified at the locus interspersed among genes for metabolic enzymes and abundant repetitive elements, especially those homologous to the CgT1 class of retrotransposons. The flanking and close markers obtained will facilitate the isolation of AVR(a22) and AVR(a12) and provide useful tools for studies of the evolution of powdery mildew fungi in agriculture and nature.
A short review of radiation-induced raft-mediated graft copolymerization: A powerful combination for modifying the surface properties of polymers in a controlled manner
Barsbay, Murat; Güven, Olgun
Surface grafting of polymeric materials is attracting increasing attention as it enables the preparation of new materials from known and commercially available polymers having desirable bulk properties such as thermal stability, elasticity, permeability, etc., in conjunction with advantageous newly tailored surface properties such as biocompatibility, biomimicry, adhesion, etc. Ionizing radiation, particularly γ radiation is one of the most powerful tools for preparing graft copolymers as it generates radicals on most substrates. With the advent of living free-radical polymerization techniques, application of γ radiation has been extended to a new era of grafting; grafting in a controlled manner to achieve surfaces with tailored and well-defined properties. This report presents the current use of γ radiation in living free-radical polymerization and highlights the use of both techniques together as a combination to present an advance in the ability to prepare surfaces with desired, tunable and well-defined properties.
A short review of radiation-induced raft-mediated graft copolymerization: A powerful combination for modifying the surface properties of polymers in a controlled manner
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Barsbay, Murat [Department of Chemistry, Hacettepe University, 06800 Beytepe, Ankara (Turkey)], E-mail: email@example.com; Gueven, Olgun [Department of Chemistry, Hacettepe University, 06800 Beytepe, Ankara (Turkey)], E-mail: firstname.lastname@example.com
Surface grafting of polymeric materials is attracting increasing attention as it enables the preparation of new materials from known and commercially available polymers having desirable bulk properties such as thermal stability, elasticity, permeability, etc., in conjunction with advantageous newly tailored surface properties such as biocompatibility, biomimicry, adhesion, etc. Ionizing radiation, particularly {gamma} radiation is one of the most powerful tools for preparing graft copolymers as it generates radicals on most substrates. With the advent of living free-radical polymerization techniques, application of {gamma} radiation has been extended to a new era of grafting; grafting in a controlled manner to achieve surfaces with tailored and well-defined properties. This report presents the current use of {gamma} radiation in living free-radical polymerization and highlights the use of both techniques together as a combination to present an advance in the ability to prepare surfaces with desired, tunable and well-defined properties.
A short review of radiation-induced raft-mediated graft copolymerization: A powerful combination for modifying the surface properties of polymers in a controlled manner
International Nuclear Information System (INIS)
Barsbay, Murat; Gueven, Olgun
Surface grafting of polymeric materials is attracting increasing attention as it enables the preparation of new materials from known and commercially available polymers having desirable bulk properties such as thermal stability, elasticity, permeability, etc., in conjunction with advantageous newly tailored surface properties such as biocompatibility, biomimicry, adhesion, etc. Ionizing radiation, particularly γ radiation is one of the most powerful tools for preparing graft copolymers as it generates radicals on most substrates. With the advent of living free-radical polymerization techniques, application of γ radiation has been extended to a new era of grafting; grafting in a controlled manner to achieve surfaces with tailored and well-defined properties. This report presents the current use of γ radiation in living free-radical polymerization and highlights the use of both techniques together as a combination to present an advance in the ability to prepare surfaces with desired, tunable and well-defined properties.
Aperfeiçoamento da técnica de Soldagem Pontual por Fricção (FSpW para união de poliamida 6 e laminado de poliamida 66 com fibra de carbono
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Joel Gonçalves
Full Text Available A Soldagem Pontual por Fricção ('Friction Spot Welding - FSpW' é uma técnica inovadora que foi desenvolvida e patenteada em 2005 pelo centro de pesquisa alemão Helmholtz Zentrum Geesthacht (HZG. A técnica apresenta ciclos rápidos, baixo custo operacional e gera soldas com alto desempenho mecânico. Foi inicialmente projetada para a soldagem de ligas metálicas leves. A soldagem de polímeros é alvo de pesquisas recentes e a soldagem de compósitos poliméricos por FSpW ainda é inédita. Este estudo demonstrou a viabilidade técnica da soldagem de chapa de poliamida 6 (PA6 e laminado de poliamida 66 e fibra de carbono (CF-PA66 por FSpW. O histórico térmico, o acabamento superficial, a microestrutura da região da solda e a resistência mecânica ao cisalhamento de juntas sobrepostas PA6/CF-PA66 foram investigados. O aumento do tamanho do anel de fixação da ferramenta original, projetada para a soldagem de metais, possibilitou a seleção de parâmetros de soldagem que resultaram em grande aporte térmico, resultando no aumento da área soldada, num menor entalhe (inscrição deixado pela ferramenta na amostra, produzindo melhoria no acabamento superficial da solda. Essa otimização resultou em uma junta PA6/CF-PA66 com resistência ao cisalhamento de 35 MPa (2196 N, com fratura predominante na placa superior de PA6.
Efecto de los procesos de compostacion y lombricultura de residuos de clavel sobre la población de Fusarium oxysporum f.sp. dianthi Effect of the processes of composting and lombricomposting of carnation residues on the population of Fusarium oxysporum f.sp. dianthi
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Pardo Fabio Alejandro
Full Text Available El manejo de los residuos vegetales es uno de los problemas que actualmente enfrenta la floricultura colombiana. El objetivo de la investigación fue estudiar el efecto de la descomposición de residuos de clavel mediante los procesos de compostación y lombricultura sobre la población de Fusarium oxysporum en una finca productora de flores
localizada en la Sabana de Bogotá. Los procesos de compostación y lombricultura redujeron de manera apreciable la población del hongo, obteniéndose la mayor reducción en el tratamiento de plantas de rosa más plantas de clavel enfermo. De 235 aislamientos de F oxysporum inoculados en esquejes de clavel de la variedad "Navidad", 37 (16% fueron patogénicos y pertenecen a F. oxysporum f.sp. dianthi, mientras que 198 aislamientos (84% correspondieron a formas no patogénicas de F oxysporum o a formas patogénicas de la especie, diferentes a la forma especial dianthi. La utilización de compost o de humus de lombriz que provenga de plantas enfermas de clavel presenta riesgos fitopatológicos importantes para su aplicación al suelo.The management of plant residues is a very important problem of the Colombian floriculture. The objetive of the research was to study the effect of descomposition of carnation plant residues with the processes of compostation and lombricompostation on the population of Fusarium oxysporum on a commercial farm located at the Bogota Plateau. Compostation and lombricompostation processes reduced significantly the population of Foxysporum. The highest reduction was obtained with the treatment of a mixture of rose plants plus carnation diseased plants. From 235 isolates of F. oxysporum inoculated on carnation cuttings of the variety "Navidad", 37 (16% were pathogenic and belong to F oxysporum f.sp. dianthi, 198 isolates (84% did not cause disease on carnation plants, so they belong to other formae specialis or they are nonpathogenic isolates of Foxysporum. The application of
Revisión: spongospora subterranea f.sp. subterranea y su virus asociado potato mop-top virus (pmtv), dos patógenos reemergentes en los cultivos de papa de colombia
Osorio Giraldo, Inés; Gutiérrez, Pablo Andrés; Marín Montoya, Mauricio
Resumen. El cultivo de papa es uno de los renglones agrícolas de mayor importancia en Colombia; se extiende a 128.701 ha y genera una producción anual de 2,3 millones de t año-1. Desde el punto vista fitosanitario, la papa se ve afectada por diversos problemas, destacándose en los últimos años la reemergencia de la sarna polvosa causada por el protozoario del suelo Spongospora subterranea f.sp. subterranea (Sss). El efecto de esta enfermedad se refleja en el deterioro de la calidad del tubérc...
Inductance and resistance measurement method for vessel detection and coil powering in all-surface inductive heating systems composed of outer squircle coils
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Veli Tayfun Kilic
Full Text Available In this work, we investigate a method proposed for vessel detection and coil powering in an all-surface inductive heating system composed of outer squircle coils. Besides conventional circular coils, coils with different shapes such as outer squircle coils are used for and enable efficient all-surface inductive heating. Validity of the method, which relies on measuring inductance and resistance values of a loaded coil at different frequencies, is experimentally demonstrated for a coil with shape different from conventional circular coil. Simple setup was constructed with a small coil to model an all-surface inductive heating system. Inductance and resistance maps were generated by measuring coil's inductance and resistance values at different frequencies loaded by a plate made of different materials and located at various positions. Results show that in an induction hob for various coil geometries it is possible to detect a vessel's presence, to identify its material type and to specify its position on the hob surface by considering inductance and resistance of the coil measured on at least two different frequencies. The studied method is important in terms of enabling safe, efficient and user flexible heating in an all-surface inductive heating system by automatically detecting the vessel's presence and powering on only the coils that are loaded by the vessel with predetermined current levels.
An atmospheric turbulence power factor to improve the estimation of surface deformation and atmosphere phase screen using SAR interferometry
Mulder, G.; van Leijen, F. J.; Barkmeijer, J.; Haan, de, S.; Hanssen, R. F.
Differential atmospheric delays in (time series) InSAR data are still a main cause for uncertainties and errors in deformation estimates. Particularly when deformation signals cannot be parameterized with steady-state models, it is hard to distinguish spatial anomalies due to deformation or atmosphere, often occurring at the same spatial scales. Most approaches for atmospheric mitigation are based on the assumption that the atmospheric signal can be `averaged out' by using tens of SAR acquisitions. Implicitly, this also assumes that the magnitude of the atmospheric signal is rather constant over time. The analysis of the atmospheric phase screen related to a wide range of weather events has shown that the atmospheric signal due to turbulent mixing always follows a distinct multi-scale power-law behavior, where a single power factor can be used to differentiate various weather types. In this study we estimate and use this power factor to optimally weight the InSAR observations in a time-series based on atmospheric turbulence. Our method uses the phase variation in interferograms on different length scales to characterize the turbulence with one turbulence power factor, following Kolmogorov turbulence theory. This is done by fitting a -5/3 to -8/3 power function through the power spectrum of our data, which gives an indication of the total turbulence strength in the whole image. The strength of this method is that the power factor metric is robust for most wide- and small-scale deformations and can be summarized with a single number for each interferogram. We show how the application of power law scaling is beneficial both for optimal deformation signal estimation as well as atmospheric phase screen estimation to operationally assimilate InSAR atmospheric data in weather models.
Surface chemical analysis and ab initio investigations of CsI coated C fiber cathodes for high power microwave sources
Vlahos, Vasilios; Morgan, Dane; LaCour, Matthew; Golby, Ken; Shiffler, Don; Booske, John H.
CsI coated C fiber cathodes are promising electron emitters utilized in field emission applications. Ab initio calculations, in conjunction with experimental investigations on CsI-spray coated C fiber cathodes, were performed in order to better understand the origin of the low turn-on E-field obtained, as compared to uncoated C fibers. One possible mechanism for lowering the turn-on E-field is surface dipole layers reducing the work function. Ab initio modeling revealed that surface monolayers of Cs, CsI, Cs2O, and CsO are all capable of producing low work function C fiber cathodes (1 eVcoabsorption of Cs and I into the fiber interior and Cs and O on the fiber surface, with no surface I. It is therefore proposed that a cesium oxide (CsxOy) surface coating is responsible, at least in part, for the low turn E-field and superior emission characteristics of this type of fiber cathode. This CsxOy layer could be formed during preconditioning heating. CsxOy surface layers cannot only lower the fiber work function by the formation of surface dipoles (if they are thin enough) but may also enhance surface emission through their ability to emit secondary electrons due to a process of grazing electron impact. These multiple electron emission processes may explain the reported 10-100 fold reduction in the turn-on E-field of coated C fibers.
Electrochemical machining of internal built-up surfaces of large-sized vessels for nuclear power plants
International Nuclear Information System (INIS)
Ryabchenko, N.N.; Pulin, V.Ya.
Electrochemical machining (ECM) has been employed for finishing of mechanically processed inner surfaces of large lateral parts of construction bodies with welded 0Kh18N10T steel overlayer. The finishing technology developed reduces the surface roughness from 10 mcm to the standard 2.5 mcm at the efficiency of machining of 2-4 m 2 per hour
Stimulative effect of the fungal biocontrol agent Fusarium oxysporum f.sp. Striga on abundance of nitrifying prokaryotes in a maize rhizosphere
Musyoki, Mary; Enowashu, Esther; Zimmermann, Judith; Muema, Esther; Wainright, Henry; Vanlauwe, Bernard; Cadisch, Georg; Rasche, Frank
The integration of resistant crop varieties and Fusarium oxysporum f.sp. strigae (Foxy-2) strains as biological control agent (BCA) has shown to be an effective control of the weed Striga hermonthica which is parasitic to several cereals (e.g., maize) cultivated in Sub-Saharan Africa. Most studies have examined the efficacy of the BCA and its interactions with host crops, while overlooking the interplay among key microorganisms in the soil nitrogen (N) cycle. Hence, we postulated that both Foxy-2 and Striga pose threats to the indigenous plant root-associated microbial communities involved in N cycling through direct or indirect competition for nutrients and that the application of high quality organic residues would compensate these effects. The primary objective of this study was thus to assess the potential impact of Foxy-2 on indigenous nitrifying prokaryotes in maize rhizosphere cultivated on two distinct soils (sandy Ferric Alisol versus clayey Humic Nitisol) obtained from Machanga and Embu, respectively, in central Kenya. These soils were treated with or without Foxy-2 and Striga; and in combination with high quality (i.e. CN ratio; 13, lignins, 8.9 % and polyphenols, 1.7 %) organic residues (i.e., Tithonia diversifolia) as N source. Using quantitative polymerase chain reaction (qPCR), we followed at three pre-defined sampling dates (14, 28 and 42 days after planting) the responses of ammonia-oxidizing archaea (AOA) and bacteria (AOB), total bacteria and archaea in four treatments of a rhizobox experiment: (i) Foxy-2 plus Striga (F+S), (ii) Striga only (C+S), (iii) Foxy-2 plus Striga plus Tithonia diversifolia residues (F+S+T), and (iv) a non-treated control (C). Overall, the treatment effects on soil microbial populations were, in comparison to the clayey Embu soil, more pronounced in the sandy Machanga soil. Contrary to our expectations, we observed a distinct stimulative, but no resource competition effect of Foxy-2 on the abundance of AOA, as well as
Genetic and physical mapping of candidate genes for resistance to Fusarium oxysporum f.sp. tracheiphilum race 3 in cowpea [Vigna unguiculata (L. Walp].
Directory of Open Access Journals (Sweden)
Marti Pottorff
Full Text Available Fusarium oxysporum f.sp. tracheiphilum (Fot is a soil-borne fungal pathogen that causes vascular wilt disease in cowpea. Fot race 3 is one of the major pathogens affecting cowpea production in California. Identification of Fot race 3 resistance determinants will expedite delivery of improved cultivars by replacing time-consuming phenotypic screening with selection based on perfect markers, thereby generating successful cultivars in a shorter time period. Resistance to Fot race 3 was studied in the RIL population California Blackeye 27 (resistant x 24-125B-1 (susceptible. Biparental mapping identified a Fot race 3 resistance locus, Fot3-1, which spanned 3.56 cM on linkage group one of the CB27 x 24-125B-1 genetic map. A marker-trait association narrowed the resistance locus to a 1.2 cM region and identified SNP marker 1_1107 as co-segregating with Fot3-1 resistance. Macro and microsynteny was observed for the Fot3-1 locus region in Glycine max where six disease resistance genes were observed in the two syntenic regions of soybean chromosomes 9 and 15. Fot3-1 was identified on the cowpea physical map on BAC clone CH093L18, spanning approximately 208,868 bp on BAC contig250. The Fot3-1 locus was narrowed to 0.5 cM distance on the cowpea genetic map linkage group 6, flanked by SNP markers 1_0860 and 1_1107. BAC clone CH093L18 was sequenced and four cowpea sequences with similarity to leucine-rich repeat serine/threonine protein kinases were identified and are cowpea candidate genes for the Fot3-1 locus. This study has shown how readily candidate genes can be identified for simply inherited agronomic traits when appropriate genetic stocks and integrated genomic resources are available. High co-linearity between cowpea and soybean genomes illustrated that utilizing synteny can transfer knowledge from a reference legume to legumes with less complete genomic resources. Identification of Fot race 3 resistance genes will enable transfer into high yielding
Surface and microstructure modifications of Ti-6Al-4V titanium alloy cutting by a water jet/high power laser converging coupling
Weiss, Laurent; Tazibt, Abdel; Aillerie, Michel; Tidu, Albert
The metallurgical evolution of the Ti-6Al-4V samples is analyzed after an appropriate cutting using a converging water jet/high power laser system. New surface microstructures are obtained on the cutting edge as a result of thermo-mechanical effects of such hybrid fluid-jet-laser tool on the targeted material. The laser beam allows to melt and the water-jet to cool down and to evacuate the material upstream according to a controlled cutting process. The experimental results have shown that a rutile layer can be generated on the surface near the cutting zone. The recorded metallurgical effect is attributed to the chemical reaction between water molecules and titanium, where the laser thermal energy brought onto the surface plays the role of reaction activator. The width of the oxidized zone was found proportional to the cutting speed. During the reaction, hydrogen gas H2 is formed and is absorbed by the metal. The hydrogen atoms trapped into the alloy change the metastable phase formation developing pure β circular grains as a skin at the kerf surface. This result is original so it would lead to innovative converging laser water jet process that could be used to increase the material properties especially for surface treatment, a key value of surface engineering and manufacturing chains.
Influence of a-Si:H deposition power on surface passivation property and thermal stability of a-Si:H/SiNx:H stacks
Directory of Open Access Journals (Sweden)
Hua Li
Full Text Available The effectiveness of hydrogenated amorphous silicon (a-Si:H layers for passivating crystalline silicon surfaces has been well documented in the literature for well over a decade. One limitation of such layers however has arisen from their inability to withstand temperatures much above their deposition temperature without significant degradation. This limitation is of importance particularly with multicrystalline silicon materials where temperatures of at least 400°C are needed for effective hydrogenation of the crystallographic defects such as grain boundaries. To address this limitation, in this work the surface passivation quality and thermal stability of a stack passivating system, combining a layer of intrinsic a-Si:H and a capping layer of silicon nitride (SiNx:H, on p-type crystalline silicon wafers is studied and optimized. In particular the sensitivity of different microwave (MW power levels for underlying a-Si:H layer deposition are examined. Both effective minority carrier lifetime (ζeff measurement and Fourier transform infrared (FTIR spectrometry were employed to study the bonding configurations, passivating quality and thermal stability of the a-Si:H/SiNx:H stacks. It is established that the higher MW power could result in increased as-deposited ζeff and implied Voc (iVoc values, indicating likely improved surface passivation quality, but that this combination degrades more quickly when exposed to prolonged thermal treatments. The more dihydride-rich film composition corresponding to the higher MW power appears to be beneficial for bond restructuring by hydrogen interchanges when exposed to short term annealing, however it also appears more susceptible to providing channels for hydrogen out-effusion which is the likely cause of the poorer thermal stability for prolonged high temperature exposure compared with stacks with underlying a-Si:H deposited with lower MW power.
Free convection heat and mass transfer in a power law fluid past an inclined surface with thermophoresis
Directory of Open Access Journals (Sweden)
Medhat M. Helal
Full Text Available The problem of heat and mass transfer in a power law, two-dimensional, laminar, boundary layer flow of a viscous incompressible fluid over an inclined plate with heat generation and thermophoresis is investigated by the characteristic function method. The governing non-linear partial differential equations describing the flow and heat transfer problem are transformed into a set of coupled non-linear ordinary differential equation which was solved using Runge–Kutta shooting method. Exact solutions for the dimensionless temperature and concentration profiles, are presented graphically for different physical parameters and for the different power law exponents 0 0.5.
Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/GaAs hybrid solar cells with 13% power conversion efficiency using front- and back-surface field.
Lin, C H; Sun, K W; Liu, Q M; Shirai, H; Lee, C P
Planar hybrid solar cells based on bulk GaAs wafers with a background doping density of 10(16) cm(-3) and poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) ( PSS) demonstrated an excellent power conversion efficiency of 8.99%. The efficiency of the cell was enhanced to 9.87% with a back-surface field feature using a molecular beam epitaxially grown n-type GaAs epi-layer. The efficiency and fill factor reach 11.86% and 0.8 when an additional p + GaAs epi-layer is deposited on the surface of the solar cells, which provides a front-surface field. The interface between the high- and low-doped regions in the polymer/GaAs and GaAs formed an electric field that introduced a barrier to minority carriers flow to the substrate and effectively reduced front surface carrier recombination, thereby enhancing light-generated free carrier collection efficiency and open-circuit voltage. Compared with the device without the front- and back-surface field, the fill factor and open-circuit voltage of the hybrid solar cell were improved from 0.76 to 0.8 and from 0.68 V to 0.77V, respectively. The highest efficiency reaches a record 13% when the Zonyl fluorosurfactant-treated PSS is used as a hole-transporting conducting layer for hybrid cells.
Directory of Open Access Journals (Sweden)
G. J. Verhoeven
Full Text Available Since a few years, structure-from-motion and multi-view stereo pipelines have become omnipresent in the cultural heritage domain. The fact that such Image-Based Modelling (IBM approaches are capable of providing a photo-realistic texture along the threedimensional (3D digital surface geometry is often considered a unique selling point, certainly for those cases that aim for a visually pleasing result. However, this texture can very often also obscure the underlying geometrical details of the surface, making it very hard to assess the morphological features of the digitised artefact or scene. Instead of constantly switching between the textured and untextured version of the 3D surface model, this paper presents a new method to generate a morphology-enhanced colour texture for the 3D polymesh. The presented approach tries to overcome this switching between objects visualisations by fusing the original colour texture data with a specific depiction of the surface normals. Whether applied to the original 3D surface model or a lowresolution derivative, this newly generated texture does not solely convey the colours in a proper way but also enhances the smalland large-scale spatial and morphological features that are hard or impossible to perceive in the original textured model. In addition, the technique is very useful for low-end 3D viewers, since no additional memory and computing capacity are needed to convey relief details properly. Apart from simple visualisation purposes, the textured 3D models are now also better suited for on-surface interpretative mapping and the generation of line drawings.
Computer Graphics Meets Image Fusion: the Power of Texture Baking to Simultaneously Visualise 3d Surface Features and Colour
Verhoeven, G. J.
Since a few years, structure-from-motion and multi-view stereo pipelines have become omnipresent in the cultural heritage domain. The fact that such Image-Based Modelling (IBM) approaches are capable of providing a photo-realistic texture along the threedimensional (3D) digital surface geometry is often considered a unique selling point, certainly for those cases that aim for a visually pleasing result. However, this texture can very often also obscure the underlying geometrical details of the surface, making it very hard to assess the morphological features of the digitised artefact or scene. Instead of constantly switching between the textured and untextured version of the 3D surface model, this paper presents a new method to generate a morphology-enhanced colour texture for the 3D polymesh. The presented approach tries to overcome this switching between objects visualisations by fusing the original colour texture data with a specific depiction of the surface normals. Whether applied to the original 3D surface model or a lowresolution derivative, this newly generated texture does not solely convey the colours in a proper way but also enhances the smalland large-scale spatial and morphological features that are hard or impossible to perceive in the original textured model. In addition, the technique is very useful for low-end 3D viewers, since no additional memory and computing capacity are needed to convey relief details properly. Apart from simple visualisation purposes, the textured 3D models are now also better suited for on-surface interpretative mapping and the generation of line drawings.
Revisión: Spongospora subterranea f.sp. subterranea y su Virus Asociado Potato mop-top virus (PMTV, Dos Patógenos Reemergentes en los Cultivos de Papa de Colombia Review: Spongospora subterranea f.sp. subterranea and its Associated Virus Potato mop-top virus (PMTV, Two Re-emerging Pathogens of Potato Crops in Colombia
Directory of Open Access Journals (Sweden)
Inés Osorio Giraldo
Full Text Available Resumen. El cultivo de papa es uno de los renglones agrícolas de mayor importancia en Colombia; se extiende a 128.701 ha y genera una producción anual de 2,3 millones de t año-1. Desde el punto vista fitosanitario, la papa se ve afectada por diversos problemas, destacándose en los últimos años la reemergencia de la sarna polvosa causada por el protozoario del suelo Spongospora subterranea f.sp. subterranea (Sss. El efecto de esta enfermedad se refleja en el deterioro de la calidad del tubérculo y en la reducción de la producción, al afectar el sistema radicular y los tubérculos. Además, Sss es el vector natural del Potato mop-top virus (PMTV, uno de los virus prevalentes en la región Andina y que presenta carácter cuarentenario en diferentes países del mundo. En esta revisión se presenta el estado de conocimiento que se tiene en el mundo sobre éstos dos fitopatógenos, haciendo énfasis en los principales hallazgos que se han realizado en Colombia sobre sus niveles de variación genética, efecto sobre la producción y métodos de detección. Se espera que la información presentada, llame la atención a los organismos estatales de sanidad vegetal, gremios de productores, asistentes técnicos y agricultores, sobre la importancia creciente que presentan dichos patógenos en los sistemas de producción de papa. Además, que sirva de base para el diseño de herramientas de diagnóstico que apoyen los esquemas de certificación de tubérculo semilla y los programas de mejoramiento genético de papa que se adelantan en Colombia.Abstract. Potato is one of the most important crops in Colombia, comprising 128.701 ha and a total production of 2.3 million t year-1. There are several phytopathological problems affecting this crop, however, the soil protozoan Spongospora subterranea f.sp. subterranea (Sss, the causal agent of powdery scab, stands out due to its recent reemergence. Powdery scab can seriously deteriorate tuber quality and
Effects of Lateral Heterogeneity and Power Law Rheology on Glacially Induced Surface Motion and Gravity Rate of Change
Wu, P.; Wang, H.; van der Wal, W.
Modern geodetic measurements from GPS, satellite altimetry, tide-gauges, Satellite Laser Ranging (SLR) and space-borne gravimetry (such as GRACE) have been used to monitor global change. Since these measurements contain contributions from glacial isostatic adjustment (GIA) and other tectonic processes, they must be modeled and removed in order to observe current climate change. In the past, most GIA models assumed that the earth is laterally homogeneous and the rheology is linear. The aim of this paper is to investigate the effects of lateral heterogeneity and Power-Law rheology on GIA induced land uplift rate, horizontal velocities, relative sealevels, J-dot and the secular gravity rate of change in the southern part of Hudson Bay, which is detected by the GRACE mission. Here, GIA is modeled with a spherical, self-gravitating, compressible viscoelastic, laterally heterogeneous earth using the Finite-Element Method. The effect of gravitationally self-consistent sea levels in realistic oceans is also included. Lateral variations in mantle viscosities and lithospheric thickness are inferred from the seismic tomography model S20A using well known scaling relationships. Power-Law rheologies in the whole mantle or in combination with linear rheologies in the upper or lower mantle are also investigated. Both ICE-5G and ICE-4G deglaciation models are used to investigate their effect on the pattern of rebound. Preliminary results show that both lateral heterogeneity and power-law rheology have strong effects on the direction and magnitude of horizontal velocities. The effects of lateral heterogeneity and power-law rheology are also large enough to be detected in land uplift rate, relative sealevels, J-dot and gravity rate of change. Their implication on observing the effects of global warming will also be discussed.
Investigation of the influence of pretreatment parameters on the surface characteristics of amorphous metal for use in power industry
Nieroda, Jolanta; Rybak, Andrzej; Kmita, Grzegorz; Sitarz, Maciej
Metallic glasses are metallic materials, which exhibit an amorphous structure. These are mostly three or more component alloys, and some of them are magnetic metals. Materials of this kind are characterized by high electrical resistivity and at the same time exhibit very good magnetic properties (e.g. low-magnetization loss). The above mentioned properties are very useful in electrical engineering industry and this material is more and more popular as a substance for high-efficiency electrical devices production. This industry area is still evolving, and thus even higher efficiency of apparatus based on amorphous material is expected. A raw material must be carefully investigated and characterized before the main production process is started. Presented work contains results of complementary examination of amorphous metal Metglas 2605. Studies involve two ways to obtain clean and oxidized surface with high reactivity, namely degreasing followed by annealing process and plasma treatment. The amorphous metal parameters were examined by means of several techniques: surface free energy (SFE) measurements by sessile drop method, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and both ex situ and in situ Raman spectroscopy. Additionally, influence of plasma parameters on wetting properties were optimized in systematic way with Design of Experiments (DOE) method. A wide range of used methods allow to fully investigate the amorphous metal material during preliminary preparation of surface. Obtained results provide information about appropriate parameters that should be applied in order to obtain highly reactive surface with functional oxide layer on it.
Influence of nickel–phosphorus surface roughness on wettability and pores formation in solder joints for high power electronic applications
Energy Technology Data Exchange (ETDEWEB)
Vivet, L., E-mail: email@example.com [Valeo, Group Electronic Expertise and Development Services, 2 rue André Boulle, 94046 Créteil (France); Joudrier, A.-L. [Institut Lavoisier de Versailles, UMR CNRS 8180, 45 Avenue des Etats-Unis, 78035 Versailles (France); Tan, K.-L.; Morelle, J.-M. [Valeo, Group Electronic Expertise and Development Services, 2 rue André Boulle, 94046 Créteil (France); Etcheberry, A. [Institut Lavoisier de Versailles, UMR CNRS 8180, 45 Avenue des Etats-Unis, 78035 Versailles (France); Chalumeau, L. [Egide, Site industriel du Sactar, 85500 Bollène (France)
Electroless nickel-high-phosphorus Ni–P plating is used as substrate coating in the electronic component technology. The ability to minimize pores formation in solder joints and the wettability of the Ni–P layer remain points of investigation. The qualities and the control of the physical and chemical properties of the deposits are essential for the reliability of the products. In this contribution it has been measured how a controlled change of one property of the Ni–P surface, its average roughness, changes the wettability of this surface before soldering completion, at ambient temperature and under ambient air, and how it contribute to change the amount and size of pores inside solder joints, after soldering completion. Before all, observations of the Ni–P surfaces using scanning electron microscopy have been achieved. Then the wettability has been measured through the determination of both the disperse and the polar fractions of the substrate surface tension, based on the measurements of the wetting angle for droplets of four different liquids, under ambient air and at room temperature (classical sessile drop technique). Finally the X-ray micro-radiography measurements of both the area fraction of pores and the size of the largest pore inside the solder joint of dice laser soldered on the studied substrate, using high melting temperature solder (300 °C, PbSnAg) have been achieved. This study clearly demonstrates that both the ability to minimize pores formation in solder joints and the wettability under ambient conditions of the Ni–P substrate decrease and become more variable when its average roughness increases. These effects can be explained considering the Cassie–Baxter model for rough surface wetting behaviour, completed by the model of heterogeneous nucleation and growth for gas bubbles inside a liquid.
Wetland Water Cooling Partnership: The Use of Constructed Wetlands to Enhance Thermoelectric Power Plant Cooling and Mitigate the Demand of Surface Water Use
Energy Technology Data Exchange (ETDEWEB)
Apfelbaum, Steven L. [Applied Ecological Services Inc., Brodhead, WI (United States); Duvall, Kenneth W. [Sterling Energy Services, LLC, Atlanta, GA (United States); Nelson, Theresa M. [Applied Ecological Services Inc., Brodhead, WI (United States); Mensing, Douglas M. [Applied Ecological Services Inc., Brodhead, WI (United States); Bengtson, Harlan H. [Sterling Energy Services, LLC, Atlanta, GA (United States); Eppich, John [Waterflow Consultants, Champaign, IL (United States); Penhallegon, Clayton [Sterling Energy Services, LLC, Atlanta, GA (United States); Thompson, Ry L. [Applied Ecological Services Inc., Brodhead, WI (United States)
Through the Phase I study segment of contract #DE-NT0006644 with the U.S. Department of Energy's National Energy Technology Laboratory, Applied Ecological Services, Inc. and Sterling Energy Services, LLC (the AES/SES Team) explored the use of constructed wetlands to help address stresses on surface water and groundwater resources from thermoelectric power plant cooling and makeup water requirements. The project objectives were crafted to explore and develop implementable water conservation and cooling strategies using constructed wetlands (not existing, naturally occurring wetlands), with the goal of determining if this strategy has the potential to reduce surface water and groundwater withdrawals of thermoelectric power plants throughout the country. Our team's exploratory work has documented what appears to be a significant and practical potential for augmenting power plant cooling water resources for makeup supply at many, but not all, thermoelectric power plant sites. The intent is to help alleviate stress on existing surface water and groundwater resources through harvesting, storing, polishing and beneficially re-using critical water resources. Through literature review, development of conceptual created wetland plans, and STELLA-based modeling, the AES/SES team has developed heat and water balances for conventional thermoelectric power plants to evaluate wetland size requirements, water use, and comparative cooling technology costs. The ecological literature on organism tolerances to heated waters was used to understand the range of ecological outcomes achievable in created wetlands. This study suggests that wetlands and water harvesting can provide a practical and cost-effective strategy to augment cooling waters for thermoelectric power plants in many geographic settings of the United States, particularly east of the 100th meridian, and in coastal and riverine locations. The study concluded that constructed wetlands can have significant positive
The creation of the analytical information system to serve the process of complex decommissioning of nuclear submarines (NSM) and surface ships (SS) with nuclear power installations (NPI)
International Nuclear Information System (INIS)
Terentiev, V.G.; Yakovlev, N.E.; Tyurin, A.V.
Management of the decommissioning of nuclear vessels includes information collection, accumulation, systematisation and analysis on the complex utilization of nuclear submarines and surface ships with nuclear power installations and on treatment of spent nuclear fuel and radioactive wastes. The relevant data on radiation and ecology, science and technology, law and economy, administration and management should be properly processed. The general objective of the analytical information system (AIS) development, described in the present paper, is the efficiency upgrading for nuclear submarine utilization management and decision making. The report considers information provision and functioning principles as well as software/hardware solutions associated with the AIS creation. (author)
Localisation of genes for resistance against ¤Blumeria graminis¤ f.sp. ¤hordei¤ and ¤Puccinia graminis¤ in a cross between a barley cultivar and a wild barley (¤Hordeum vulgare¤ ssp. ¤spontaneum¤) line
DEFF Research Database (Denmark)
Backes, G.; Madsen, L.H.; Jaiser, H.
The aims of this investigation have been to map new (quantitative) resistance genes against powdery mildew, caused by Blumeria graminis f.sp. hordei L., and leaf rust, caused by Puccinia hordei L., in a cross between the barley (Hordeum vulgare ssp. vulgare) cultivar "Vada" and the wild barley...
Effect of input power and gas pressure on the roughening and selective etching of SiO2/Si surfaces in reactive plasmas
International Nuclear Information System (INIS)
Zhong, X. X.; Huang, X. Z.; Tam, E.; Ostrikov, K.; Colpo, P.; Rossi, F.
We report on the application low-temperature plasmas for roughening Si surfaces which is becoming increasingly important for a number of applications ranging from Si quantum dots to cell and protein attachment for devices such as 'laboratory on a chip' and sensors. It is a requirement that Si surface roughening is scalable and is a single-step process. It is shown that the removal of naturally forming SiO 2 can be used to assist in the roughening of the surface using a low-temperature plasma-based etching approach, similar to the commonly used in semiconductor micromanufacturing. It is demonstrated that the selectivity of SiO 2 /Si etching can be easily controlled by tuning the plasma power, working gas pressure, and other discharge parameters. The achieved selectivity ranges from 0.4 to 25.2 thus providing an effective means for the control of surface roughness of Si during the oxide layer removal, which is required for many advance applications in bio- and nanotechnology.
Surface-enhanced resonance Raman scattering (SERRS) spectroscopy: a powerful technique for the forensic analysis of colorants?
White, Peter C.; Rodger, Caroline; Rutherford, Vicky; Finnon, Yvonne; Smith, W. Ewen; Fitzgerald, Mary P.
During the past five years work in our laboratory has been concentrated on developing SERRS spectroscopy and making it a simple and robust technique for the analyses of colorants. It has proved to be highly discriminative, extremely sensitive and possible to identify dyes in mixtures without their prior separation. Additionally, by using concentrated silver colloid solutions, in-situ analyses have now been accomplished with minimal or in some cases no visual destruction of the item being examined and with virtually no background interference from the surfaces on which the stains or smears have been deposited. To illustrate the methodology and the potential of SERRS various applications including the in-situ analyses of the dyes on cotton fibers and stains from cosmetics, shoe polishes, inks and drinks on various surfaces are presented.
The Screw-Like Movement of a Gliding Bacterium Is Powered by Spiral Motion of Cell-Surface Adhesins.
Shrivastava, Abhishek; Roland, Thibault; Berg, Howard C
Flavobacterium johnsoniae, a rod-shaped bacterium, glides over surfaces at speeds of ∼2 μm/s. The propulsion of a cell-surface adhesin, SprB, is known to enable gliding. We used cephalexin to generate elongated cells with irregular shapes and followed their displacement in three dimensions. These cells rolled about their long axes as they moved forward, following a right-handed trajectory. We coated gold nanoparticles with an SprB antibody and tracked them in three dimensions in an evanescent field where the nanoparticles appeared brighter when they were closer to the glass. The nanoparticles followed a right-handed spiral trajectory on the surface of the cell. Thus, if SprB were to adhere to the glass rather than to a nanoparticle, the cell would move forward along a right-handed trajectory, as observed, but in a direction opposite to that of the nanoparticle. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.
Remote Monitoring of Near-Surface Soil Moisture Dynamics In Unstable Slopes Using a Low-Power Autonomous Resistivity Imaging System
Chambers, J. E.; Meldrum, P.; Gunn, D.; Wilkinson, P. B.; Uhlemann, S.; Swift, R. T.; Kuras, O.; Inauen, C.; Hutchinson, D.; Butler, S.
ERT monitoring has been demonstrated in numerous studies as an effective means of imaging near surface processes for applications as diverse as permafrost studies and contaminated land assessment. A limiting factor in applying time-lapse ERT for long-term studies in remote locations has been the availability of cost-effective ERT measurement systems designed specifically for monitoring applications. Typically, monitoring is undertaken using repeated manual data collection, or by building conventional survey instruments into a monitoring setup. The latter often requires high power and is therefore difficult to operate remotely without access to mains electricity. We describe the development of a low-power resistivity imaging system designed specifically for remote monitoring, taking advantage of, e.g., solar power and data telemetry. Here, we present the results of two field deployments. The system has been installed on an active railway cutting to provide insights into the effect of vegetation on the moisture dynamics in unstable infrastructure slopes and to gather subsurface information for pro-active remediation measures. The system, comprising 255 electrodes, acquires 4596 reciprocal measurement pairs twice daily during standard operation. In case of severe weather events, the measurement schedule is reactively changed, to gather high temporal resolution data to image rainfall infiltration processes. The system has also been installed along a leaking and marginally stable canal embankment; a less favourable location for remote monitoring, with limited solar power and poor mobile reception. Nevertheless, the acquired data indicated the effectiveness of remedial actions on the canal. The ERT results showed that one leak was caused by the canal and fixed during remediation, while two other "leaks" were shown to be effects of groundwater dynamics. The availability of cost-effective, low-power ERT monitoring instrumentation, combined with an automated workflow of
Stochastic techno-economic assessment based on Monte Carlo simulation and the Response Surface Methodology: The case of an innovative linear Fresnel CSP (concentrated solar power) system
International Nuclear Information System (INIS)
Bendato, Ilaria; Cassettari, Lucia; Mosca, Marco; Mosca, Roberto
Combining technological solutions with investment profitability is a critical aspect in designing both traditional and innovative renewable power plants. Often, the introduction of new advanced-design solutions, although technically interesting, does not generate adequate revenue to justify their utilization. In this study, an innovative methodology is developed that aims to satisfy both targets. On the one hand, considering all of the feasible plant configurations, it allows the analysis of the investment in a stochastic regime using the Monte Carlo method. On the other hand, the impact of every technical solution on the economic performance indicators can be measured by using regression meta-models built according to the theory of Response Surface Methodology. This approach enables the design of a plant configuration that generates the best economic return over the entire life cycle of the plant. This paper illustrates an application of the proposed methodology to the evaluation of design solutions using an innovative linear Fresnel Concentrated Solar Power system. - Highlights: • A stochastic methodology for solar plants investment evaluation. • Study of the impact of new technologies on the investment results. • Application to an innovative linear Fresnel CSP system. • A particular application of Monte Carlo simulation and response surface methodology.
Lower-extremity resistance training on unstable surfaces improves proxies of muscle strength, power and balance in healthy older adults: a randomised control trial
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Nils Eckardt
Full Text Available Abstract Background It is well documented that both balance and resistance training have the potential to mitigate intrinsic fall risk factors in older adults. However, knowledge about the effects of simultaneously executed balance and resistance training (i.e., resistance training conducted on unstable surfaces [URT] on lower-extremity muscle strength, power and balance in older adults is insufficient. The objective of the present study was to compare the effects of machine-based stable resistance training (M-SRT and two types of URT, i.e., machine-based (M-URT and free-weight URT (F-URT, on measures of lower-extremity muscle strength, power and balance in older adults. Methods Seventy-five healthy community-dwelling older adults aged 65–80 years, were assigned to three intervention groups: M-SRT, M-URT and F-URT. Over a period of ten weeks, all participants exercised two times per week with each session lasting ~60 min. Tests included assessment of leg muscle strength (e.g., maximal isometric leg extension strength, power (e.g., chair rise test and balance (e.g., functional reach test, carried out before and after the training period. Furthermore, maximal training load of the squat-movement was assessed during the last training week. Results Maximal training load of the squat-movement was significantly lower in F-URT in comparison to M-SRT and M-URT. However, lower-extremity resistance training conducted on even and uneven surfaces meaningfully improved proxies of strength, power and balance in all groups. M-URT produced the greatest improvements in leg extension strength and F-URT in the chair rise test and functional reach test. Conclusion Aside from two interaction effects, overall improvements in measures of lower-extremity muscle strength, power and balance were similar across training groups. Importantly, F-URT produced similar results with considerably lower training load as compared to M-SRT and M-URT. Concluding, F-URT seems an
The background concentration of the tritium in surface water before operation of the nuclear power plant Temelin
International Nuclear Information System (INIS)
Tomasek, M.; Wilhelmova, L.
In this announcement the results of the tritium determination in surface waters in the period 1991-1996 are summarized. The water samples from Vltava river under the estuary of waste canal of the NPP Temelin and on the entrance in Prague water-work were taken away. Moreover, the samples from local rivers in the area of NPP Temelin construction which can be contaminated by scouring after condensation of the gaseous exhalation of the NPP were taken away. The samples by standard method in month interval were taken away. From every sample for the measurement of the tritium activity two parallel samples were prepared. The tritium activity with the scintillation spectrometer at the optimal conditions was measured. From measured values seasonal character and gradual decreasing of tritium activity in observed period is evident. Maximal activities obviously in the summer months are observed. From the exponential regression half time of decreasing of the tritium activity 8.1 year was calculated [sk
Note: Proton irradiation at kilowatt-power and neutron production from a free-surface liquid-lithium target
Energy Technology Data Exchange (ETDEWEB)
Halfon, S.; Feinberg, G. [Soreq NRC, Yavne 81800 (Israel); Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Arenshtam, A.; Kijel, D.; Weissman, L.; Aviv, O.; Berkovits, D.; Dudovitch, O.; Eisen, Y.; Eliyahu, I.; Haquin, G.; Hazenshprung, N.; Kreisel, A.; Mardor, I.; Shimel, G.; Shor, A.; Silverman, I.; Yungrais, Z. [Soreq NRC, Yavne 81800 (Israel); Paul, M., E-mail: firstname.lastname@example.com; Tessler, M. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)
The free-surface Liquid-Lithium Target, recently developed at Soreq Applied Research Accelerator Facility (SARAF), was successfully used with a 1.9 MeV, 1.2 mA (2.3 kW) continuous-wave proton beam. Neutrons (∼2 × 10{sup 10} n/s having a peak energy of ∼27 keV) from the {sup 7}Li(p,n){sup 7}Be reaction were detected with a fission-chamber detector and by gold activation targets positioned in the forward direction. The setup is being used for nuclear astrophysics experiments to study neutron-induced reactions at stellar energies and to demonstrate the feasibility of accelerator-based boron neutron capture therapy.
Detection of Fungal Spores Using a Generic Surface Plasmon Resonance Immunoassay
DEFF Research Database (Denmark)
Skottrup, Peter Durand; Hearty, Stephen; Frøkiær, Hanne
This paper describes a biosensor-based method for detection of fungal spores using Surface Plasmon Resonance (SPR). The approach involves the use of a mouse monoclonal antibody (Pst mAb8) and a SPR sensor for label-free detection of urediniospores from the model organism Puccinia striiformis f.......sp. tritici (Pst). In the subtractive inhibition assay, urediniospores and Pst mAb8 were mixed, urediniospore-bound Pst mAb8 removed by centrifugation and the remaining Pst mAb8 quantified using the SPR sensor. Assay conditions were optimised and a detection limit of 3.1 x 105 urediniospores/ml was achieved...
Deposition Assessment Of Anthropogenic Airborne 210Po And 210Pb In The Mosses And Surface Soil At The Vicinity Of A Coal-Fired Power Plant
International Nuclear Information System (INIS)
Zal U'yun Wan Mahmood; Nita Salina Abu Bakar; Abdul Kadir Ishak
Anthropogenic airborne depositions of 210 Po and 210 Pb in the mosses and surface soil collected at the vicinity of a coal-fired power plant were assessed. The purpose of the study was to determine activity concentrations of 210 Po, 210 Pb and its activity ratio ( 210 Po/ 210 Pb). Other purposes were to determine their concentration factor (CF) in relation to track the potential source of those radionuclides and to identify most suitable moss species as a biological indicator for atmospheric deposition contaminants. In this study, different species of mosses Leucobryum aduncum, Campylopus serratus, Syrrhopodon ciliates and Vesicularia montagnei were collected in May 2011 at the area around 30 km radius from Tanjung Bin coal-fired power plant located in Pontian, Johor. The activity concentrations of 210 Po 210 Pb and 210 Po/ 210 Pb in mosses were in the range of 76.81 ± 4.94 - 251.33 ± 16.33 Bqkg -1 dry wt., 54.37 ± 3.38 - 164.63 ± 11.64 Bqkg -1 dry wt. and 1.10 - 2.00, respectively. Meanwhile the ranges for those radionuclides in the surface soil were 33.53 ± 2.10 - 183.93 ± 12.01 Bqkg -1 dry wt., 17.92 ± 1.18 - 298.60 ± 23.70 Bqkg -1 dry wt. and 1.57 - 2.44, respectively. Corresponding high ability of Leucobryum aduncum to accumulate more 210 Po and 210 Pb, wide geographical distribution, most abundant and high CF, therefore, the findings can be concluded this species was the most suitable as a biological indicator for atmospheric deposition contaminants such as 210 Po and 210 Pb. Furthermore, it is clear the accumulation of 210 Po and 210 Pb in mosses might be supplied from various sources of atmospheric deposition such as coal-fired power plant operation, industrial, agriculture and fertilizer activities, burned fuel fossil and forest; and other potential sources. Meanwhile, the main source of 210 Po and 210 Pb in surface soil is supplied from the in situ decay of radon and radium. (author)
Study and characterization of noble metal deposits on similar rusty surfaces to those of the reactor U-1 type BWR of nuclear power station of Laguna Verde
International Nuclear Information System (INIS)
Flores S, V. H.
In the present investigation work, were determined the parameters to simulate the conditions of internal oxidation reactor circulation pipes of the nuclear power plant of Laguna Verde in Veracruz. We used 304l stainless steel cylinders with two faces prepared with abrasive paper of No. 600, with the finality to obtain similar surface to the internal circulation piping nuclear reactor. Oxides was formed within an autoclave (Autoclave MEX-02 unit B), which is a device that simulates the working conditions of the nuclear reactor, but without radiation generated by the fission reaction within the reactor. The oxidation conditions were a temperature of 280 C and pressure of 8 MPa, similar conditions to the reactor operating in nuclear power plant of Laguna Verde in Veracruz, Mexico (BWR conditions), with an average conductivity of 4.58 ms / cm and 2352 ppb oxygen to simulate normal water chemistry NWC. Were obtained deposits of noble metal oxides formed on 304l stainless steel samples, in a 250 ml autoclave at a temperature range of 180 to 200 C. The elements that were used to deposit platinum-rhodium (Pt-Rh) with aqueous Na 2 Pt (OH) 6 and Na 3 Rh (NO 2 ) 6 , Silver (Ag) with an aqueous solution of AgNO 3 , zirconium (Zr) with aqueous Zr O (NO 3 ) and ZrO 2 , and zinc (Zn) in aqueous solution of Zn (NO 3 ) 2 under conditions of normal water chemistry. Also there was the oxidation of 304l stainless steel specimens in normal water chemistry with a solution of Zinc (Zn) (NWC + Zn). Oxidation of the specimens in water chemistry with a solution of zinc (Zn + NWC) was prepared in two ways: within the MEX-02 autoclave unit A in a solution of zinc and a flask at constant temperature in zinc solution. The oxides formed and deposits were characterized by scanning electron microscopy, energy dispersive X-ray analysis, elemental field analysis and X-ray diffraction. By other hand was evaluated the electrochemical behavior of the oxides formed on the surface of 304l stainless steel
Results of Steam-Water-Oxygen Treatment of the Inside of Heating Surfaces in Heat-Recovery Steam Generators of the PGU-800 Power Unit at the Perm' District Thermal Power Station
Ovechkina, O. V.; Zhuravlev, L. S.; Drozdov, A. A.; Solomeina, S. V.
Prestarting, postinstallation steam-water-oxygen treatment (SWOT) of the natural circulation/steam reheat heat-recovery steam generators (HRSG) manufactured by OAO Krasny Kotelshchik was performed at the PGU-800 power unit of the Perm District Thermal Power Station (GRES). Prior to SWOT, steam-oxygen cleaning, passivation, and preservation of gas condensate heaters (GCH) of HRSGs were performed for 10 h using 1.3MPa/260°C/70 t/h external steam. After that, test specimens were cut out that demonstrated high strength of the passivating film. SWOT of the inside of the heating surfaces was carried out during no-load operation of the gas turbine unit with an exhaust temperature of 280-300°C at the HRSG inlet. The steam turbine was shutdown, and the generated steam was discharged into the atmosphere. Oxygen was metered into the discharge pipeline of the electricity-driven feed pumps and downcomers of the evaporators. The behavior of the concentration by weight of iron compounds and the results of investigation of cutout specimens by the drop or potentiometric method indicate that the steam-water-oxygen process makes it possible to remove corrosion products and reduce the time required to put a boiler into operation. Unlike other processes, SWOT does not require metal-intensive cleaning systems, temporary metering stations, and structures for collection of the waste solution.
Laser Ultrasonic System for Surface Crack Visualization in Dissimilar Welds of Control Rod Drive Mechanism Assembly of Nuclear Power Plant
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Yun-Shil Choi
Full Text Available In this paper, we propose a J-groove dissimilar weld crack visualization system based on ultrasonic propagation imaging (UPI technology. A full-scale control rod drive mechanism (CRDM assembly specimen was fabricated to verify the proposed system. An ultrasonic sensor was contacted at one point of the inner surface of the reactor vessel head part of the CRDM assembly. Q-switched laser beams were scanned to generate ultrasonic waves around the weld bead. The localization and sizing of the crack were possible by ultrasonic wave propagation imaging. Furthermore, ultrasonic spectral imaging unveiled frequency components of damage-induced waves, while wavelet-transformed ultrasonic propagation imaging enhanced damage visibility by generating a wave propagation video focused on the frequency component of the damage-induced waves. Dual-directional anomalous wave propagation imaging with adjacent wave subtraction was also developed to enhance the crack visibility regardless of crack orientation and wave propagation direction. In conclusion, the full-scale specimen test demonstrated that the multiple damage visualization tools are very effective in the visualization of J-groove dissimilar weld cracks.
Low-power, high-uniform, and forming-free resistive memory based on Mg-deficient amorphous MgO film with rough surface
Guo, Jiajun; Ren, Shuxia; Wu, Liqian; Kang, Xin; Chen, Wei; Zhao, Xu
Saving energy and reducing operation parameter fluctuations remain crucial for enabling resistive random access memory (RRAM) to emerge as a universal memory. In this work, we report a resistive memory device based on an amorphous MgO (a-MgO) film that not only exhibits ultralow programming voltage (just 0.22 V) and low power consumption (less than 176.7 μW) but also shows excellent operative uniformity (the coefficient of variation is only 1.7% and 2.2% for SET and RESET voltage, respectively). Moreover, it also shows a forming-free characteristic. Further analysis indicates that these distinctive properties can be attributed to the unstable local structures and the rough surface of the Mg-deficient a-MgO film. These findings show the potential of using a-MgO in high-performance nonvolatile memory applications.
Mid-infrared PbTe vertical external cavity surface emitting laser on Si-substrate with above 1 W output power
Rahim, M.; Fill, M.; Felder, F.; Chappuis, D.; Corda, M.; Zogg, H.
Mid-infrared vertical external cavity surface emitting lasers (VECSELs) emitting above 1 W output power in pulsed mode and up to 17 mW in continuous mode at -172 °C were realized. Emission wavelength changes from 5 μm at -172 °C to 3.6 μm at 20 °C heat sink temperature. The active medium is a one wavelength thick PbTe layer grown by molecular beam epitaxy on a Si-substrate. It is followed by a 2.5 pair Pb1-yEuyTe/EuTe epitaxial Bragg mirror. The cavity is completed with an external curved Pb1-yEuyTe/BaF2 mirror. The VECSEL is optically pumped with 1.55 μm wavelength laser and In-soldered to Cu heat sink. No microstructural processing is needed.
Over-summering of wheat stripe rust (Puccinia striiformis f.sp. tritici in the California Central valley: A case study Supervivencia estival de la roya estriada (Puccinia striiformis f.sp. tritici del trigo en el Valle Central de California: Estudio de caso
Directory of Open Access Journals (Sweden)
Huib Tollenaar
Full Text Available To study the over-summering of wheat stripe rust (Puccinia striiformis f.sp. tritici in the California Central Valley (CCV, temperature records from various locations in the CCV during the period 1950-2009 were examined for the occurrence of lethal maximum temperatures for the uredinia and uredinio-mycelium of this fungus. The lethal upper threshold temperature for the uredinial stage of P.s. tritici, estimated to be 40.5 °C on the basis of data published elsewhere, and the sum, accumulated during ten consecutive days, of the respective lethal temperature quotients (ALTQio, accounting for the partial lethal effect of the daily ambient temperatures between 30 and 40.5 °C on the uredinial stage of P.s. tritici, were used as yardsticks for thermal lethality. The results indicate that, in these 60 yr, the uredinia and the uredinio-mycelium of P.s. tritici could not possibly have over-summered at any of the locations studied. The Sierra Nevada Mountains, together with the Tulelake Basin and the coastal zone of the Pacific Ocean are the only two areas in California with appropriate environmental conditions for the summer-survival of the uredinial stage of stripe rust. Therefore, it is presumed that the inoculum for the initial infections of P.s. tritici in wheat fields in the CCV during the following growing season originates in either one or both of these areas, although, a potential third source of inoculum for the initial infections of stripe rust in the CCV could also be involved. Namely, the possible presence of telia with viable teliospores of P.s. tritici in autumn on straw of the threshed wheat fields or on volunteer wheat plants in the CCV, in conjunction with the accidental concurrence of nearby stripe rust susceptible barberry (Berberis spp., could lead to the development of alternative, endogenous sources of inoculum in the CCV.Para estudiar la supervivencia estival de la roya estriada (Puccinia striiformis f.sp. tritici del trigo
Surface enhancement of cold work tool steels by friction stir processing with a pinless tool
Costa, M. I.; Verdera, D.; Vieira, M. T.; Rodrigues, D. M.
The microstructure and mechanical properties of enhanced tool steel (AISI D2) surfaces produced using a friction stir welding (FSW) related procedure, called friction stir processing (FSP), are analysed in this work. The surface of the tool steel samples was processed using a WC-Co pinless tool and varying processing conditions. Microstructural analysis revealed that meanwhile the original substrate structure consisted of a heterogeneous distribution of coarse carbides in a ferritic matrix, the transformed surfaces consisted of very small carbides, homogenously distributed in a ferrite- bainite- martensite matrix. The morphology of the surfaces, as well as its mechanical properties, evaluated by hardness and tensile testing, were found to vary with increasing tool rotation speed. Surface hardness was drastically increased, relative to the initial hardness of bulk steel. This was attributed to ferrite and carbide refinement, as well as to martensite formation during solid state processing. At the highest rotation rates, tool sliding during processing deeply compromised the characteristics of the processed surfaces.
Monitoring peak power and cooling energy savings of shade trees and white surfaces in the Sacramento Municipal Utility District (SMUD) service area: Project design and preliminary results
Energy Technology Data Exchange (ETDEWEB)
Akbari, H.; Bretz, S.; Hanford, J.; Rosenfeld, A.; Sailor, D.; Taha, H. [Lawrence Berkeley Lab., CA (United States); Bos, W. [Sacramento Municipal Utility District, CA (United States)
Urban areas in warm climates create summer heat islands of daily average intensity of 3--5{degrees}C, adding to discomfort and increasing air-conditioning loads. Two important factors contributing to urban heat islands are reductions in albedo (lower overall city reflectance) and loss of vegetation (less evapotranspiration). Reducing summer heat islands by planting vegetation (shade trees) and increasing surface albedos, saves cooling energy, allows down-sizing of air conditioners, lowers air-conditioning peak demand, and reduces the emission of CO{sub 2} and other pollutants from electric power plants. The focus of this multi-year project, jointly sponsored by SMUD and the California Institute for Energy Efficiency (CIEE), was to measure the direct cooling effects of trees and white surfaces (mainly roofs) in a few buildings in Sacramento. The first-year project was to design the experiment and obtain base case data. We also obtained limited post retrofit data for some sites. This report provides an overview of the project activities during the first year at six sites. The measurement period for some of the sites was limited to September and October, which are transitional cooling months in Sacramento and hence the interpretation of results only apply to this period. In one house, recoating the dark roof with a high-albedo coating rendered air conditioning unnecessary for the month of September (possible savings of up to 10 kWh per day and 2 kW of non-coincidental peak power). Savings of 50% relative to an identical base case bungalow were achieved when a school bungalow`s roof and southeast wall were coated with a high-albedo coating during the same period. Our measured data for the vegetation sites do not indicate conclusive results because shade trees were small and the cooling period was almost over. We need to collect more data over a longer cooling season in order to demonstrate savings conclusively.
Experience of high-nitrogenous steel powder application in repairs and surface hardening of responsible parts for power equipment by plasma spraying
Kolpakov, A. S.; Kardonina, N. I.
The questions of the application of novel diffusion-alloying high-nitrogenous steel powders for repair and surface hardening of responsible parts of power equipment by plasma spraying are considered. The appropriateness of the method for operative repair of equipment and increasing its service life is justified. General data on the structure, properties, and manufacture of nitrogen-, aluminum-, and chromium-containing steel powders that are economically alloyed using diffusion are described. It is noted that the nitrogen release during the decomposition of iron nitrides, when heating, protects the powder particles from oxidation in the plasma jet. It is shown that the coating retains 50% of nitrogen that is contained in the powder. Plasma spraying modes for diffusion-alloying high-nitrogenous steel powders are given. The service properties of plasma coatings based on these powders are analyzed. It is shown that the high-nitrogenous steel powders to a nitrogen content of 8.9 wt % provide the necessary wear resistance and hardness of the coating and the strength of its adhesion to the substrate and corrosion resistance to typical aggressive media. It is noted that increasing the coating porosity promotes stress relaxation and increases its thickness being limited with respect to delamination conditions in comparison with dense coatings on retention of the low defectiveness of the interface and high adhesion to the substrate. The examples of the application of high-nitrogenous steel powders in power engineering during equipment repairs by service companies and overhaul subdivisions of heat power plants are given. It is noted that the plasma spraying of diffusion-alloyed high-nitrogenous steel powders is a unique opportunity to restore nitrided steel products.
Study of deposited crud composition on fuel surfaces in the environment of hydrogen water chemistry (HWC) of a Boiling Water Reactor at Chinshan Nuclear Power Plant
International Nuclear Information System (INIS)
Tsai, Tsuey-Lin; Lin, Tzung-Yi; Su, Te-Yen; Wen, Tung-Jen; Men, Lee-Chung
This paper aimed at the characterization of metallic composition and surface analysis on the crud of fuel rods for unit-1 of BWR-4 at Nuclear Power Plant. The inductively coupled plasma- atomic emission spectroscopy (ICPAES) and the gamma spectrometry were carried out to analyze the corrosion product distributions and to determine the elemental compositions along the fuel rod under conditions of hydrogen water chemistry (HWC) switched from normal water chemistry (NWC) of reactor coolant in this study. Most of the crud consisted of the flakes and irregular shapes via SEM morphology. The loosely adherent oxide layer was mostly composed of hematite (α- Fe 2 O 3 ) with amorphous iron oxides by XRD results. The average deposited amounts of crud was the order of 0.5 mg/cm 2 , indicating that the fuel surface of this plant under HWC environment appeared to be one with the lower crud deposition in terms of low iron level of feedwater. It also showed no significant difference in comparison with NWC condition. (authors)
Surface Modification by Friction Stir Processing of Low-Carbon Steel: Microstructure Investigation and Wear Performance
Sattari, Behnoosh; Shamanian, Morteza; Salimijazi, Farshid; Salehi, Mehdi
A low-carbon steel sheet with a thickness of 5 mm was subjected to friction stir processing (FSP) by one to four different passes. The microstructures of different regions were characterized using the optical microscopy and electron backscatter diffraction. The Vickers micro-harness was measured at the distance of 200 μm below the processed surfaces. The influence of pass numbers (PNs) on wear resistance was studied in terms of coefficients of friction (CoFs), weight losses and wear rates. SEM topographies of the worn surfaces were also studied to evaluate the wear mechanisms. Microstructure observations showed that Widmänstatten ferrite plates were formed in stir zones (SZs) and heat affected zones. As PN increased, these grains were widened due to the increment of the carbon diffusivity and lengthened because of the high heat input and microstructure anisotropy. Besides, increasing the PN causes increasing of the hardness and wear resistance, simultaneously. Specifically, the wear rate in the SZ was reduced from 2.8 × 10-2 mm3 m-1 in base metal to 0.3 × 10-2 mm3 m-1 in sample which was subjected to 4 FSP passes. However, variation in PN had no considerable effect on CoFs. Oxidative wear mechanism was observed on the worn surface of the steel and the FSPed samples while more debris was formed by increasing the PNs.
Surface Modification by Friction Stir Processing of Low-Carbon Steel: Microstructure Investigation and Wear Performance
Sattari, Behnoosh; Shamanian, Morteza; Salimijazi, Farshid; Salehi, Mehdi
A low-carbon steel sheet with a thickness of 5 mm was subjected to friction stir processing (FSP) by one to four different passes. The microstructures of different regions were characterized using the optical microscopy and electron backscatter diffraction. The Vickers micro-harness was measured at the distance of 200 μm below the processed surfaces. The influence of pass numbers (PNs) on wear resistance was studied in terms of coefficients of friction (CoFs), weight losses and wear rates. SEM topographies of the worn surfaces were also studied to evaluate the wear mechanisms. Microstructure observations showed that Widmänstatten ferrite plates were formed in stir zones (SZs) and heat affected zones. As PN increased, these grains were widened due to the increment of the carbon diffusivity and lengthened because of the high heat input and microstructure anisotropy. Besides, increasing the PN causes increasing of the hardness and wear resistance, simultaneously. Specifically, the wear rate in the SZ was reduced from 2.8 × 10-2 mm3 m-1 in base metal to 0.3 × 10-2 mm3 m-1 in sample which was subjected to 4 FSP passes. However, variation in PN had no considerable effect on CoFs. Oxidative wear mechanism was observed on the worn surface of the steel and the FSPed samples while more debris was formed by increasing the PNs.
Friction stir surfacing of cast A356 aluminium–silicon alloy with boron carbide and molybdenum disulphide powders
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R. Srinivasu
Full Text Available Good castability and high strength properties of Al–Si alloys are useful in defence applications like torpedoes, manufacture of Missile bodies, and parts of automobile such as engine cylinders and pistons. Poor wear resistance of the alloys is major limitation for their use. Friction stir processing (FSP is a recognized surfacing technique as it overcomes the problems of fusion route surface modification methods. Keeping in view of the requirement of improving wear resistance of cast aluminium–silicon alloy, friction stir processing was attempted for surface modification with boron carbide (B4C and molybdenum disulfide (MoS2 powders. Metallography, micro compositional analysis, hardness and pin-on-disc wear testing were used for characterizing the surface composite coating. Microscopic study revealed breaking of coarse silicon needles and uniformly distributed carbides in the A356 alloy matrix after FSP. Improvement and uniformity in hardness was obtained in surface composite layer. Higher wear resistance was achieved in friction stir processed coating with carbide powders. Addition of solid lubricant MoS2 powder was found to improve wear resistance of the base metal significantly.
Biomass-derived nitrogen-doped porous carbons with tailored hierarchical porosity and high specific surface area for high energy and power density supercapacitors
Sun, Junting; Niu, Jin; Liu, Mengyue; Ji, Jing; Dou, Meiling; Wang, Feng
Porous carbon materials with hierarchical structures attract intense interest for the development of high-performance supercapacitors. Herein, we demonstrate a facile and efficient strategy to synthesize nitrogen-doped hierarchically porous carbons with tailored porous structure combined with high specific surface area (SSA), which involves a pre-carbonization and a subsequent carbonization combined with KOH activation of silkworm cocoon precursors. Through adjusting the mass ratio of the activator (KOH) to pre-carbonized precursor in the activation process, the hierarchically porous carbon prepared at the mass ratio of 2 (referred to as NHPC-2) possesses a high defect density and a high SSA of 3386 m2 g-1 as well as the relatively high volumetric proportion of mesopores and macropores (45.5%). As a result, the energy density and power density of the symmetric supercapacitor based on NHPC-2 electrode are as high as 34.41 Wh kg-1 and 31.25 kW kg-1 in organic-solvent electrolyte, and are further improved to 112.1 Wh kg-1 and 23.91 kW kg-1 in ionic-liquid electrolyte.
In situ electrochemical impedance spectroscopy/synchrotron radiation grazing incidence X-ray diffraction-A powerful new technique for the characterization of electrochemical surfaces and interfaces
International Nuclear Information System (INIS)
De Marco, Roland; Jiang, Z.-T.; Martizano, Jay; Lowe, Alex; Pejcic, Bobby; Riessen, Arie van
A marriage of electrochemical impedance spectroscopy (EIS) and in situ synchrotron radiation grazing incidence X-ray diffraction (SR-GIXRD) has provided a powerful new technique for the elucidation of the mechanistic chemistry of electrochemical systems. In this study, EIS/SR-GIXRD has been used to investigate the influence of metal ion buffer calibration ligands, along with natural organic ligands in seawater, on the behaviour of the iron chalcogenide glass ion-selective electrode (ISE). The SR-GIXRD data demonstrated that citrate - a previously reported poor iron calibration ligand for the analysis of seawater - induced an instantaneous and total dissolution of crystalline GeSe and Sb 2 Se 3 in the modified surface layer (MSL) of the ISE, while natural organic ligands in seawater and a mixture of ligands in a mimetic seawater ligand system protected the MSL's crystalline inclusions of GeSe and Sb 2 Se 3 from oxidative attack. Expectedly, the EIS data showed that citrate induced a loss in the medium frequency time constant for the MSL of the ISE, while seawater's natural organic ligands and the mimetic ligand system preserved the medium frequency EIS response characteristics of the ISE's MSL. The new EIS/SR-GIXRD technique has provided insights into the suitability of iron calibration ligands for the analysis of iron in seawater
Barley Mla and Rar mutants compromised in the hypersensitive cell death response against Blumeria graminis f.sp. hordei are modified in their ability to accumulate reactive oxygen intermediates at sites of fungal invasion.
Hückelhoven, R; Fodor, J; Trujillo, M; Kogel, K H
The pathogenesis-related accumulation of superoxide radical anions (O2*-) and hydrogen peroxide (H2O2) was comparatively analyzed in a barley line (Hordeum vulgare L. cv Sultan-5) carrying the powdery mildew (Blumeria graminis f.sp. hordei, Speer, Bgh) resistance gene Mla12, and in susceptible mutants defective in Mla12 or in genes "required for Mla12-specified disease resistance" (Rar1 and Rar2). In-situ localization of reactive oxygen intermediates was performed both by microscopic detection of azide-insensitive nitroblue tetrazolium (NBT) reduction or diaminobenzidine (DAB) polymerization, and by an NBT-DAB double-staining procedure. The Mla12-mediated hypersensitive cell death occurred either in attacked epidermal cells or adjacent mesophyll cells of wild-type plants. Whole-cell H2O2 accumulation was detected in dying cells, while O2*- emerged in adjacent cells. Importantly, all susceptible mutants lacked these reactions. An oxalate oxidase, which is known to generate H2O2 and has been implicated in barley resistance against the powdery mildew fungus, was not differentially expressed between the wild type and all mutants. The results demonstrate that the Rar1 and Rar2 gene products, which are control elements of R-gene-mediated programmed cell death, also control accumulation of reactive oxygen intermediates but not the pathogenesis-related expression of oxalate oxidase.
Direct observation of 134Cs and 137Cs in surface seawater in the western and central North Pacific after the Fukushima Dai-ichi nuclear power plant accident
Directory of Open Access Journals (Sweden)
H. Kaeriyama
Full Text Available The horizontal distribution of radioactive cesium (Cs derived from the Fukushima Dai-ichi nuclear power plant (FNPP in the North Pacific is still unclear due to the limitation of direct measurement of the seawater in the open ocean. We present the result of direct observation of radioactive Cs in surface seawater collected from a broad area in the western and central North Pacific in July 2011, October 2011 and July 2012. We also conducted a simple particle tracking experiment to estimate the qualitative spatial distribution of radioactive Cs in the North Pacific. 134Cs was detected at 94 stations out of 123 stations, and 137Cs was detected at all stations. High 134Cs and 137Cs concentrations more than 10 m Bq kg−1 were observed in the area of the northern part of Kuroshio Extension at 144° E and 155° E in July 2011, in the area 147–175° E around 40° N in October 2011, and the northern part of Kuroshio Extension at 155° E and 175°30´ E in July 2012. Combining the result of direct observations and particle tracking experiment, the radioactive Cs derived from the FNPP had been dispersed eastward to the central North Pacific during 2011. It was considered from the horizontal distribution that radioactive Cs was dispersed not only eastward but also north- and southward in the central North Pacific. Pronounced dilution process of radioactive Cs from the FNPP during study period is suggested from temporal change in the activity ratio of 134Cs / 137Cs, which was decay-corrected on 6 April 2011, and relationships between radioactive Cs and temperature.
Characterization of Aluminum-Based-Surface Matrix Composites with Iron and Iron Oxide Fabricated by Friction Stir Processing
Mahmoud, Essam R. I.; Tash, Mahmoud M.
Surface composite layers were successfully fabricated on an A 1050-H24 aluminum plate by dispersed iron (Fe) and magnetite (Fe3O4) particles through friction stir processing (FSP). Fe and Fe3O4 powders were packed into a groove of 3 mm in width and 1.5 mm in depth, cut on the aluminum plate, and covered with an aluminum sheet that was 2-mm thick. A friction stir processing (FSP) tool of square probe shape, rotated at a rate of 1000–2000 rpm, was plunged into the plate through the cover sheet and the groove, and moved along the groove at a travelling speed of 1.66 mm/s. Double and triple passes were applied. As a result, it is found that the Fe particles were homogenously distributed in the whole nugget zone at a rotation speed of 1000 rpm after triple FSP passes. Limited interfacial reactions occurred between the Fe particles and the aluminum matrix. On the other hand, the lower rotation speed (1000 rpm) was not enough to form a sound nugget when the dispersed particles were changed to the larger Fe3O4. The Fe3O4 particles were dispersed homogenously in a sound nugget zone when the rotation speed was increased to 1500 rpm. No reaction products could be detected between the Fe3O4 particles and the aluminum matrix. The saturation magnetization (Ms) of the Fe-dispersed nugget zone was higher than that of the Fe3O4-dispersed nugget zone. Moreover, there were good agreement between the obtained saturation magnetization values relative to that of pure Fe and Fe3O4 materials and the volume content of the dispersed particles in the nugget zone. PMID:28773629
Properties of surface layer of X40CrMoV5-1 in the relation to remelting conditions by the use of a high power diode laser
International Nuclear Information System (INIS)
Dobrzanski, L.A.; Bonek, M.; Klimpel, A.
Investigations included remelting experiments on the X40CrMoV5-1 hot-work steel with the high power diode laser. Tests have been made using the high power diode laser (HPDL) in the technological process of remelting. The effect of remelting parameters on structure and properties of its surface layer, as well as on remelting geometry and shape. The influence of the technological conditions and their effect on the mechanical properties of the surface layer, and especially its hardness has been tested. Dependence of the microhardness changes, on the degree of the laser beam influence on the treated surface, and mostly on the hardness increase in the remelted layer is presented. The influence of remelting process parameters on the structure of substrate material is presented. Guidelines for remelting of the X40CrMoV5-1 steel surface using the high power diode laser feature the outcome of the investigation aimed at obtaining its optimum mechanical and working properties. (author)
The receptor-like MLO protein and the RAC/ROP family G-protein RACB modulate actin reorganization in barley attacked by the biotrophic powdery mildew fungus Blumeria graminis f.sp. hordei.
Opalski, Krystina S; Schultheiss, Holger; Kogel, Karl-Heinz; Hückelhoven, Ralph
Cytoskeleton remodelling is a crucial process in determining the polarity of dividing and growing plant cells, as well as during interactions with the environment. Nothing is currently known about the proteins, which regulate actin remodelling during interactions with invading pathogens. The biotrophic powdery mildew fungus Blumeria graminis f.sp. hordei (Bgh) invades susceptible barley (Hordeum vulgare L.) by penetrating epidermal cells, which remain intact during fungal development. In contrast, resistant host plants prevent infection by inhibiting penetration through apoplastic mechanisms, which require focusing defence reactions on the site of attack. We stained actin filaments in a susceptible Mlo-genotype and a near-isogenic race-non-specifically resistant barley mlo5-mutant genotype using fluorescence-labelled phalloidin after chemical fixation. This revealed that the actin cytoskeleton is differentially reorganized in susceptible and resistant hosts challenged by Bgh. Actin filaments were polarized towards the sites of attempted penetration in the resistant host, whereas when susceptible hosts were penetrated, a more subtle reorganization took place around fungal haustoria. Strong actin filament focusing towards sites of fungal attack was closely associated with successful prevention of penetration. Actin focusing was less frequent and seemingly delayed in susceptible wild-type barley expressing the susceptibility factor MLO. Additionally, single cell overexpression of a constitutively activated RAC/ROP G-protein, CA RACB, another potential host susceptibility factor and hypothetical actin cytoskeleton regulator, partly inhibited actin reorganization when under attack from Bgh, whereas knockdown of RACB promoted actin focusing. We conclude that RACB and, potentially, MLO are host proteins involved in the modulation of actin reorganization and cell polarity in the interaction of barley with Bgh.
Localisation of genes for resistance against Blumeria graminis f.sp. hordei and Puccinia graminis in a cross between a barley cultivar and a wild barley (Hordeum vulgare ssp. spontaneum) line.
Backes, G; Madsen, L H; Jaiser, H; Stougaard, J; Herz, M; Mohler, V; Jahoor, A
The aims of this investigation have been to map new (quantitative) resistance genes against powdery mildew, caused by Blumeria graminis f.sp. hordei L., and leaf rust, caused by Puccinia hordei L., in a cross between the barley ( Hordeum vulgare ssp. vulgare) cultivar "Vada" and the wild barley ( Hordeum vulgare ssp. spontaneum) line "1B-87" originating from Israel. The population consisted of 121 recombinant inbred lines. Resistance against leaf rust and powdery mildew was tested on detached leaves. The leaf rust isolate "I-80" and the powdery mildew isolate "Va-4", respectively, were used for the infection in this experiment. Moreover, powdery mildew disease severity was observed in the field at two different epidemic stages. In addition to other DNA markers, the map included 13 RGA (resistance gene analog) loci. The structure of the data demanded a non-parametric QTL-analysis. For each of the four observations, two QTLs with very high significance were localised. QTLs for resistance against powdery mildew were detected on chromosome 1H, 2H, 3H, 4H and 7H. QTLs for resistance against leaf rust were localised on 2H and 6H. Only one QTL was common for two of the powdery mildew related traits. Three of the seven QTLs were localised at the positions of the RGA-loci. Three of the five powdery mildew related QTLs are sharing their chromosomal position with known qualitative resistance genes. All detected QTLs behaved additively. Possible sources of the distorted segregation observed, the differences between the results for the different powdery mildew related traits and the relation between qualitative and quantitative resistance are discussed.
Meteosat SEVIRI Fire Radiative Power (FRP) products from the Land Surface Analysis Satellite Applications Facility (LSA SAF) - Part 1: Algorithms, product contents and analysis
Wooster, M. J.; Roberts, G.; Freeborn, P. H.; Xu, W.; Govaerts, Y.; Beeby, R.; He, J.; Lattanzio, A.; Mullen, R.
Characterising changes in landscape scale fire activity at very high temporal resolution is best achieved using thermal observations of actively burning fires made from geostationary Earth observation (EO) satellites. Over the last decade or more, a series of research and/or operational "active fire" products have been developed from these types of geostationary observations, often with the aim of supporting the generation of data related to biomass burning fuel consumption and trace gas and aerosol emission fields. The Fire Radiative Power (FRP) products generated by the Land Surface Analysis Satellite Applications Facility (LSA SAF) from data collected by the Meteosat Second Generation (MSG) Spinning Enhanced Visible and Infrared Imager (SEVIRI) are one such set of products, and are freely available in both near real-time and archived form. Every 15 min, the algorithms used to generate these products identify and map the location of new SEVIRI observations containing actively burning fires, and characterise their individual rates of radiative energy release (fire radiative power; FRP) that is believed proportional to rates of biomass consumption and smoke emission. The FRP-PIXEL product contains the highest spatial resolution FRP dataset, delivered for all of Europe, northern and southern Africa, and part of South America at a spatial resolution of 3 km (decreasing away from the west African sub-satellite point) at the full 15 min temporal resolution. The FRP-GRID product is an hourly summary of the FRP-PIXEL data, produced at a 5° grid cell size and including simple bias adjustments for meteorological cloud cover and for the regional underestimation of FRP caused, primarily, by the non-detection of low FRP fire pixels at SEVIRI's relatively coarse pixel size. Here we describe the enhanced geostationary Fire Thermal Anomaly (FTA) algorithm used to detect the SEVIRI active fire pixels, and detail methods used to deliver atmospherically corrected FRP information
Enhancement of light output power of GaN-based light-emitting diodes with photonic quasi-crystal patterned on p-GaN surface and n-side sidewall roughing
In this paper, GaN-based light-emitting diodes (LEDs) with photonic quasi-crystal (PQC) structure on p-GaN surface and n-side roughing by nano-imprint lithography are fabricated and investigated. At an injection current of 20 mA, the LED with PQC structure on p-GaN surface and n-side roughing increased the light output power of the InGaN/GaN multiple quantum well LEDs by a factor of 1.42, and the wall-plug efficiency is 26% higher than the conventional GaN-based LED type. After 500-h life test (55°C/50 mA), it was found that the normalized output power of GaN-based LED with PQC structure on p-GaN surface and n-side roughing only decreased by 6%. These results offer promising potential to enhance the light output powers of commercial light-emitting devices using the technique of nano-imprint lithography. PMID:23683526
Kubát, M
The book contains a summary of our knowledge of power semiconductor structures. It presents first a short historic introduction (Chap. I) as well as a brief selection of facts from solid state physics, in particular those related to power semiconductors (Chap. 2). The book deals with diode structures in Chap. 3. In addition to fundamental facts in pn-junction theory, the book covers mainly the important processes of power structures. It describes the emitter efficiency and function of microleaks (shunts). the p +p and n + n junctions, and in particular the recent theory of the pin, pvn and p1tn junctions, whose role appears to be decisive for the forward mode not only of diode structures but also of more complex ones. For power diode structures the reverse mode is the decisive factor in pn-junction breakdown theory. The presentation given here uses engineering features (the multiplication factor M and the experimentally detected laws for the volume and surface of crystals), which condenses the presentation an...
Differences in rates of decrease of environmental radiation dose rates by ground surface property in Fukushima City after the Fukushima Daiichi nuclear power plant accident.
Kakamu, Takeyasu; Kanda, Hideyuki; Tsuji, Masayoshi; Kobayashi, Daisuke; Miyake, Masao; Hayakawa, Takehito; Katsuda, Shin-ichiro; Mori, Yayoi; Okouchi, Toshiyasu; Hazama, Akihiro; Fukushima, Tetsuhito
After the Great East Japan Earthquake on 11 March 2011, the environmental radiation dose in Fukushima City increased. On 11 April, 1 mo after the earthquake, the environmental radiation dose rate at various surfaces in the same area differed greatly by surface property. Environmental radiation measurements continue in order to determine the estimated time to 50% reduction in environmental radiation dose rates by surface property in order to make suggestions for decontamination in Fukushima. The measurements were carried out from 11 April to 11 November 2011. Forty-eight (48) measurement points were selected, including four kinds of ground surface properties: grass (13), soil (5), artificial turf (7), and asphalt (23). Environmental radiation dose rate was measured at heights of 100 cm above the ground surface. Time to 50% reduction of environmental radiation dose rates was estimated for each ground surface property. Radiation dose rates on 11 November had decreased significantly compared with those on 11 April for all surface properties. Artificial turf showed the longest time to 50% reduction (544.32 d, standard error: 96.86), and soil showed the shortest (213.20 d, standard error: 35.88). The authors found the environmental radiation dose rate on artificial materials to have a longer 50% reduction time than that on natural materials. These results contribute to determining an order of priority for decontamination after nuclear disasters.
Influence of fossil-fuel power plant emissions on the surface fine particulate matter in the Seoul Capital Area, South Korea.
Kim, Byeong-Uk; Kim, Okgil; Kim, Hyun Cheol; Kim, Soontae
The South Korean government plans to reduce region-wide annual PM2.5 (particulate matter with an aerodynamic diameter ≤2.5 μm) concentrations in the Seoul Capital Area (SCA) from 2010 levels of 27 µg/m(3) to 20 µg/m(3) by 2024. At the same time, it is inevitable that emissions from fossil-fuel power plants will continue to increase if electricity generation expands and the generation portfolio remains the same in the future. To estimate incremental PM2.5 contributions due to projected electricity generation growth in South Korea, we utilized an ensemble forecasting member of the Integrated Multidimensional Air Quality System for Korea based on the Community Multi-scale Air Quality model. We performed sensitivity runs with across-the-board emission reductions for all fossil-fuel power plants in South Korea to estimate the contribution of PM2.5 from domestic fossil-fuel power plants. We estimated that fossil-fuel power plants are responsible for 2.4% of the annual PM2.5 national ambient air quality standard in the SCA as of 2010. Based on the electricity generation and the annual contribution of fossil-fuel power plants in 2010, we estimated that annual PM2.5 concentrations may increase by 0.2 µg/m(3) per 100 TWhr due to additional electricity generation. With currently available information on future electricity demands, we estimated that the total future contribution of fossil-fuel power plants would be 0.87 µg/m(3), which is 12.4% of the target reduction amount of the annual PM2.5 concentration by 2024. We also approximated that the number of premature deaths caused by existing fossil-fuel power plants would be 736 in 2024. Since the proximity of power plants to the SCA and the types of fuel used significantly impact this estimation, further studies are warranted on the impact of physical parameters of plants, such as location and stack height, on PM2.5 concentrations in the SCA due to each precursor. Improving air quality by reducing fine particle
Effect of a rough surface on the aerodynamic characteristics of a two-bladed wind-powered engine with cylindrical blades
Tanasheva, N. K.; Kunakbaev, T. O.; Dyusembaeva, A. N.; Shuyushbayeva, N. N.; Damekova, S. K.
We have reported the results of experiments on determining the drag coefficient and the thrust coefficient of a two-bladed wind-powered engine based on the Magnus effect with rotating rough cylinders in the range of air flow velocity of 4-10 m/s (Re = 26800-90000) for a constant rotation number of a cylindrical blade about its own axis. The results show that an increase in the Reynolds number reduces the drag coefficient and the thrust coefficient. The extent of the influence of the relative roughness on the aerodynamic characteristics of the two-bladed wind-powered engine has been experimentally established.
Houts, Michael G.
Fission power and propulsion systems can enable exciting space exploration missions. These include bases on the moon and Mars; and the exploration, development, and utilization of the solar system. In the near-term, fission surface power systems could provide abundant, constant, cost-effective power anywhere on the surface of the Moon or Mars, independent of available sunlight. Affordable access to Mars, the asteroid belt, or other destinations could be provided by nuclear thermal rockets. In the further term, high performance fission power supplies could enable both extremely high power levels on planetary surfaces and fission electric propulsion vehicles for rapid, efficient cargo and crew transfer. Advanced fission propulsion systems could eventually allow routine access to the entire solar system. Fission systems could also enable the utilization of resources within the solar system.
PowerSat: A technology demonstration of a solar power satellite
Sigler, Douglas L. (Editor); Riedman, John; Duracinski, Jon; Edwards, Joe; Brown, Garry; Webb, Ron; Platzke, Mike; Yuan, Xiaolin; Rogers, Pete; Khan, Afsar
PowerSat is a preliminary design strategy for microwave wireless power transfer of solar energy. Solar power satellites convert solar power into microwave energy and use wireless power transmission to transfer the power to the Earth's surface. The PowerSat project will show how new developments in inflatable technology can be used to deploy solar panels and phased array antennas.
African Journals Online (AJOL)
molecules of fungal or plant origin that could enhance resistance to powdery mildew in wheat as an alternative to chemical fungicides. The protection ... association avec un fongicide anti-oïdium. (Hukkanen et al., 2007) ; des polysaccharides ..... être à l'origine d'un signal d'activation des réactions de défense reconnu ...
Thermal dimensioning of the deep repository. Influence of canister spacing, canister power, rock thermal properties and nearfield design on the maximum canister surface temperature
International Nuclear Information System (INIS)
Hoekmark, Harald; Faelth, Billy
The report addresses the problem of the minimum spacing required between neighbouring canisters in the deep repository. That spacing is calculated for a number of assumptions regarding the conditions that govern the temperature in the nearfield and at the surfaces of the canisters. The spacing criterion is that the temperature at the canister surfaces must not exceed 100 deg C .The results are given in the form of nomographic charts, such that it is in principle possible to determine the spacing as soon as site data, i.e. the initial undisturbed rock temperature and the host rock heat transport properties, are available. Results of canister spacing calculations are given for the KBS-3V concept as well as for the KBS-3H concept. A combination of numerical and analytical methods is used for the KBS-3H calculations, while the KBS-3V calculations are purely analytical. Both methods are described in detail. Open gaps are assigned equivalent heat conductivities, calculated such that the conduction across the gaps will include also the heat transferred by radiation. The equivalent heat conductivities are based on the emissivities of the different gap surfaces. For the canister copper surface, the emissivity is determined by back-calculation of temperatures measured in the Prototype experiment at Aespoe HRL. The size of the different gaps and the emissivity values are of great importance for the results and will be investigated further in the future
Study in vitro of dental enamel irradiated with a high power diode laser operating at 960 nm: morphological analysis of post-irradiation dental surface and thermal effect analysis in pulp chamber due to laser application
International Nuclear Information System (INIS)
Quinto Junior, Jose
Objectives: This study examines the structural and thermal modifications induced in dental enamel under dye assisted diode laser irradiation. The aim of this study is to verify if this laser-assisted treatment is capable to modify the enamel surface by causing fusion of the enamel surface layer. At the same time, the pulpal temperature rise must be kept low enough in order not to cause pulpar necrosis. To achieve this target, it is necessary to determine suitable laser parameters. As is known, fusion of the enamel surface followed by re-solidification produce a more acid resistant layer. This surface treatment is being researched as a new method for caries prevention. Method and Materials: A series of fourteen identically prepared enamel samples of human teeth were irradiated with a high power diode laser operating at 960 nm and using fiber delivery. Prior to irradiation, a fine layer of cromophorous ink was applied to the enamel surface. In the first part of the experiment the best parameter for pulse duration was determined. In the second part of the experimental phase the same energy density was used but with different repetition rates. During irradiation we monitored the temperature rise in the pulpal cavity. The morphology of the treated samples was analysed under SEM. Results: The morphology of the treated samples showed a homogeneously re-solidified enamel layer. The results of the temperature analysis showed a decrease of the pulpal temperature rise with decreasing repetition rate. Conclusion: With the diode laser it is possible to cause morphological alterations of the enamel surface, which is known to increase the enamel resistance against acid attack, and still maintain the temperature rise in the pulpar chamber below damage threshold. (author)
The effect of high-flux H plasma exposure with simultaneous transient heat loads on tungsten surface damage and power handling
Czech Academy of Sciences Publication Activity Database
van Eden, G.G.; Morgan, T.W.; van der Meiden, H.J.; Matějíček, Jiří; Chráska, Tomáš; Wirtz, M.; De Temmerman, G.
Roč. 54, č. 12 (2014), s. 123010-123010 ISSN 0029-5515 R&D Projects: GA ČR(CZ) GA14-12837S Institutional support: RVO:61389021 Keywords : ELMs * tungsten * thermal shock * melting * surface analysis * laser * hydrogen Subject RIV: JG - Metallurgy Impact factor: 3.062, year: 2014 http://iopscience.iop.org/0029-5515/54/12/123010/pdf/0029-5515_54_12_123010.pdf
Plasma sprayed TiO2: The influence of power of an electric supply on relations among stoichiometry, surface state and photocatalytic decomposition of acetone
Czech Academy of Sciences Publication Activity Database
Ctibor, Pavel; Štengl, Václav; Píš, I.; Zahoranová, T.; Nehasil, V.
Roč. 38, č. 4 (2012), s. 3453-3458 ISSN 0272-8842 R&D Projects: GA AV ČR IAAX00430803 Institutional research plan: CEZ:AV0Z20430508; CEZ:AV0Z40320502 Keywords : Spectroscopy * TiO2 * Plasma spraying * Photocatalysis Subject RIV: JK - Corrosion ; Surface Treatment of Materials; CA - Inorganic Chemistry (UACH-T) Impact factor: 1.789, year: 2012 http://www.sciencedirect.com/science/article/pii/S0272884211011278
Research and development of photovoltaic power system. Research on surface passivation for high-efficiency silicon solar cells; Taiyoko hatsuden system no kenkyu kaihatsu. Hyomen passivation no kenkyu
Energy Technology Data Exchange (ETDEWEB)
Saito, T. [Tokyo Univ. of Agriculture and Technology, Tokyo (Japan). Faculty of Technology
This paper reports the result obtained during fiscal 1994 on research on surface passivation of high-efficiency silicon solar cells. In research on carrier recombination on SiO2/doped silicon interface, measurements were carried out on minority carrier life with respect to p-type silicon substrates with which phosphorus with high and low concentrations are diffused uniformly on the surface and non-uniformly on the back and then oxidized. The measurements were performed for the purpose of evaluating the carrier recombination at p-n junctions. Effective life time of oxidized test samples increased longer than that of prior to the oxidization as a result of effect of surface passivation contributing remarkably. In research on reduction in carrier recombination on SiO2/Si interface by using H radical annealing, experiments were conducted by using a method that uses more active H-atoms. As a result, it was revealed that the reduction effect is recognized at as low temperature as 200{degree}C, and photo-bias effect is also noticeable. Other research activities included analytic research on minority carrier recombination on micro crystalline silicon/crystalline silicon interface, and experimental research on evaluation of minority carrier life of poly-crystalline silicon wafers. 6 figs.
Continuous wave operation of high power GaN-based blue vertical-cavity surface-emitting lasers using epitaxial lateral overgrowth
Hamaguchi, Tatsushi; Fuutagawa, Noriyuki; Izumi, Shouichiro; Murayama, Masahiro; Narui, Hironobu
We have succeeded in achieving continuous-wave operation of gallium nitride (GaN) based vertical-cavity surfaceemitting lasers (VCSELs), which was fabricated by epitaxial lateral overgrowth (ELO) using dielectric distributed Bragg reflectors(DBRs) as masks for selective growth. The device exhibited CW operation at a wavelength of 453.9nm. The maximum output power was 1.1 mW, which is the highest value reported in previously published articles. The ELO process used for this study represents a breakthrough for challenges which were indicated by other former reports for GaN-based VCSELs and is suitable for mass production.
A Generic Method for Fungal Spore Detection: The use of a monoclonal antibody and surface plasmon resonance
DEFF Research Database (Denmark)
Skottrup, Peter; Hearty, Stephen; Frøkiær, Hanne
This study describes a biosensing principle for detection of fungal spores using surface plasmon resonance (SPR). The approach involves the use of a monoclonal antibody (mab) and a SPR sensor for label-free detection of the model organism Puccinia striiformis f.sp. tritici (Pst) a biotrophic fungus...... causing wheat yellow rust. We have developed mabs towards intact whole spores and used a subtractive inhibition format for detection of spores in solution. The antibody was incubated with different spore concentrations and the remaining free antibody was quantified using a BIAcore® 3000 sensor. Decreasing...... binding of mab to the sensor surface was observed as the Pst urediniospore concentration was increased. The detection range for the assay was 1.7 x 106 – 5.3 x 104 spores/ml. This study describes the first use of SPR for detection of fungal spores and the generic principle has the potential to be used...
A Generic Method for Fungal Spore Detection: The use of a monoclonal antibody and surface plasmon resonance
DEFF Research Database (Denmark)
Skottrup, Peter Durand; Hearty, Stephen; Frøkiær, Hanne
This study describes a biosensing principle for detection of fungal spores using surface plasmon resonance (SPR). The approach involves the use of a monoclonal antibody (mab) and a SPR sensor for label-free detection of the model organism Puccinia striiformis f.sp. tritici (Pst) a biotrophic fungus...... causing wheat yellow rust. We have developed mabs towards intact whole spores and used a subtractive inhibition format for detection of spores in solution. The antibody was incubated with different spore concentrations and the remaining free antibody was quantified using a BIAcore® 3000 sensor....... Decreasing binding of mab to the sensor surface was observed as the Pst urediniospore concentration was increased. The detection range for the assay was 1.7 x 106 – 5.3 x 104 spores/ml. This study describes the first use of SPR for detection of fungal spores and the generic principle has the potential...
A Generic Method for Fungal Spore Detection: The use of a monoclonal antibody and surface plasmon resonance
DEFF Research Database (Denmark)
Skottrup, Peter; Hearty, Stephen; Frøkiær, Hanne
This study describes a biosensing principle for detection of fungal spores using surface plasmon resonance (SPR). The approach involves the use of a monoclonal antibody (mab) and a SPR sensor for label-free detection of the model organism Puccinia striiformis f.sp. tritici (Pst) a biotrophic fungus...... causing wheat yellow rust. We have developed mabs towards intact whole spores and used a subtractive inhibition format for detection of spores in solution. The antibody was incubated with different spore concentrations and the remaining free antibody was quantified using a BIAcore® 3000 sensor. Decreasing...... binding of mab to the sensor surface was observed as the Pst urediniospore concentration was increased. The detection range for the assay was 1.7 x 106 – 5.3 x 104 spores/ml. This study describes the first use of SPR for detection of fungal spores and the generic principle has the potential to be used...
Directory of Open Access Journals (Sweden)
Full Text Available The twenty years period past after the contamination with radionuclides in 1986, as a result of the accident in the Chernobyl's NPP, allowed the accumulation of rich data base for the radiation status of the soils in Bulgaria. Objective of many years studies were virgin soils from high mountain areas, hilly and flat (the region of Kozlodouy NPP and the Danube river valley. Ceasium-137 and strontium-90 were the main men-made radionuclides detected in the examined Bulgarian soils, few years after the accident. The content of ceasium-137 and strontium-90 in the soils from high mountain areas (Rodopa and Rila mountains is several times higher then that in the soils from Northern Bulgaria and Sofia field. High non-homogeneity in the pollution within small areas (scores of square meters even was determined. No significant horizontal redistribution was observed for the period after 1986. The tendency of changes in the radioactive status of the soils in Bulgaria after the accident at the Chernobyl Nuclear Power Plant is not due to trans-border transfer of radioactive materials or to any breakdown at the Kosloduy Nuclear Power Plant.
Miyanishi, Masayoshi
Open algebraic surfaces are a synonym for algebraic surfaces that are not necessarily complete. An open algebraic surface is understood as a Zariski open set of a projective algebraic surface. There is a long history of research on projective algebraic surfaces, and there exists a beautiful Enriques-Kodaira classification of such surfaces. The research accumulated by Ramanujan, Abhyankar, Moh, and Nagata and others has established a classification theory of open algebraic surfaces comparable to the Enriques-Kodaira theory. This research provides powerful methods to study the geometry and topology of open algebraic surfaces. The theory of open algebraic surfaces is applicable not only to algebraic geometry, but also to other fields, such as commutative algebra, invariant theory, and singularities. This book contains a comprehensive account of the theory of open algebraic surfaces, as well as several applications, in particular to the study of affine surfaces. Prerequisite to understanding the text is a basic b...
Microstructure and microhardness of AA1050/TiC surface composite ...
Indian Academy of Sciences (India)
composites which is based on the basic principles of friction stir welding (FSW). The distinct advantages of the FSP are microstructural refinement, densification, homogeneity, accurate con- trol and variable depth of the processed zone. FSP is a green and energy efficient technique without deleterious gas and does not ...
Effect of variable viscosity on free flow of non-Newtonian power-law fluids along a vertical surface with thermal stratification
Directory of Open Access Journals (Sweden)
Moorthy M.B.K.
Full Text Available The aim of this paper is to investigate the effect of thermal stratification together with variable viscosity on free convection flow of non- Newtonian fluids along a nonisothermal semi infinite vertical plate embedded in a saturated porous medium. The governing equations of continuity, momentum and energy are transformed into nonlinear ordinary differential equations using similarity transformations and then solved by using the Runge-Kutta-Gill method along with shooting technique. Governing parameters for the problem under study are the variable viscosity, thermal stratification parameter, non-Newtonian parameter and the power-law index parameter.The velocity and temperature distributions are presented and discussed. The Nusselt number is also derived and discussed numerically.
Power electronics substrate for direct substrate cooling
Le, Khiet [Mission Viejo, CA; Ward, Terence G [Redondo Beach, CA; Mann, Brooks S [Redondo Beach, CA; Yankoski, Edward P [Corona, CA; Smith, Gregory S [Woodland Hills, CA
Systems and apparatus are provided for power electronics substrates adapted for direct substrate cooling. A power electronics substrate comprises a first surface configured to have electrical circuitry disposed thereon, a second surface, and a plurality of physical features on the second surface. The physical features are configured to promote a turbulent boundary layer in a coolant impinged upon the second surface.
Relação entre a estrutura foliar de feijoeiro e a pré-infecção por Glomerella cingulata f.sp. phaseoli Relationship between bean leaf structure and the Glomerella cingulata f.sp. phaseoli preinfection
Directory of Open Access Journals (Sweden)
Vanessa de Fátima Jerba
Full Text Available Os objetivos deste trabalho foram mensurar a área da nervura secundária e quantificar o número de tricomas da superfície foliar de cultivares de feijoeiro suscetível (Carioca, moderadamente resistente (Pérola e resistente (IAPAR-81 à antracnose, e observar as relações entre tais características com o estágio pré-infeccional. Para mensurar a área da nervura secundária, fragmentos foliares foram amostrados, fixados em FAA 50, conservados em álcool 70%, infiltrados em resina glicol-metacrilato, cortados transversalmente e corados com azul de toluidina. Os tricomas foram quantificados em impressões epidérmicas em microscópio de projeção. Na análise pré-infeccional, o material foi fixado em glutaraldeído 2,5% e processado para o estudo ao microscópio eletrônico de varredura. A cultivar resistente apresentou menor área de nervura secundária e maior pilosidade que a cultivar moderadamente resistente e a suscetível. Na cultivar resistente, por causa da menor área de nervura e maior pilosidade, o patógeno permaneceu sobre a nervura e envolvido com o tricoma. Na cultivar suscetível, com maior área de nervura e menor pilosidade, foram observadas necrose e estruturas fúngicas na superfície foliar. Há relação entre estas características foliares e a resistência à antracnose durante o estágio pré-infeccional do patógeno.The objectives of this work were to measure the secondary vein area and to quantify the trichomes of leaf surface in bean cultivar susceptible (Carioca, medium resistant (Pérola and resistant (IAPAR-81 to anthracnose, and to observe relationships between leaf blade characteristics with the preinfectional stages. In order to measure the secondary vein area, sample leaf pieces were fixed in FAA 50 and conserved in 70% alcohol. These leaf samples were infiltrated in glycol metacrylate resin, cut transversally and stained with toluidine blue. The trichomes were quantified in epidermical impressions in
INSTRUMENTS AND METHODS OF INVESTIGATION: Generation of high-order harmonics of high-power lasers in plasmas produced under irradiation of solid target surfaces by a prepulse
Ganeev, Rashid A.
Research on high-order harmonic generation in laser-produced plasmas is reviewed. We analyze the conditions for the generation of harmonics (up to the 101st order, λ = 7.9 nm) in the propagation of laser radiation through a weakly ionized plasma prepared by irradiating the surfaces of different targets with a laser prepulse. We discuss the findings of investigations into the resonance intensity enhancement of individual harmonics in a number of plasma formations, which have demonstrated a substantial increase in the conversion efficiency in the plateau region of the harmonic-order distribution (in particular, of the 13th harmonic in indium plasmas with the efficiency 10-4). We review the results of investigations of harmonic generation in nanoparticle-containing plasmas. Different techniques for increasing the intensity and order of the generated harmonics are discussed.
Numerical investigation of magnetohydrodynamic slip flow of power-law nanofluid with temperature dependent viscosity and thermal conductivity over a permeable surface
Hussain, Sajid; Aziz, Asim; Khalique, Chaudhry Masood; Aziz, Taha
In this paper, a numerical investigation is carried out to study the effect of temperature dependent viscosity and thermal conductivity on heat transfer and slip flow of electrically conducting non-Newtonian nanofluids. The power-law model is considered for water based nanofluids and a magnetic field is applied in the transverse direction to the flow. The governing partial differential equations(PDEs) along with the slip boundary conditions are transformed into ordinary differential equations(ODEs) using a similarity technique. The resulting ODEs are numerically solved by using fourth order Runge-Kutta and shooting methods. Numerical computations for the velocity and temperature profiles, the skin friction coefficient and the Nusselt number are presented in the form of graphs and tables. The velocity gradient at the boundary is highest for pseudoplastic fluids followed by Newtonian and then dilatant fluids. Increasing the viscosity of the nanofluid and the volume of nanoparticles reduces the rate of heat transfer and enhances the thickness of the momentum boundary layer. The increase in strength of the applied transverse magnetic field and suction velocity increases fluid motion and decreases the temperature distribution within the boundary layer. Increase in the slip velocity enhances the rate of heat transfer whereas thermal slip reduces the rate of heat transfer.
Numerical investigation of magnetohydrodynamic slip flow of power-law nanofluid with temperature dependent viscosity and thermal conductivity over a permeable surface
Directory of Open Access Journals (Sweden)
Hussain Sajid
Full Text Available In this paper, a numerical investigation is carried out to study the effect of temperature dependent viscosity and thermal conductivity on heat transfer and slip flow of electrically conducting non-Newtonian nanofluids. The power-law model is considered for water based nanofluids and a magnetic field is applied in the transverse direction to the flow. The governing partial differential equations(PDEs along with the slip boundary conditions are transformed into ordinary differential equations(ODEs using a similarity technique. The resulting ODEs are numerically solved by using fourth order Runge-Kutta and shooting methods. Numerical computations for the velocity and temperature profiles, the skin friction coefficient and the Nusselt number are presented in the form of graphs and tables. The velocity gradient at the boundary is highest for pseudoplastic fluids followed by Newtonian and then dilatant fluids. Increasing the viscosity of the nanofluid and the volume of nanoparticles reduces the rate of heat transfer and enhances the thickness of the momentum boundary layer. The increase in strength of the applied transverse magnetic field and suction velocity increases fluid motion and decreases the temperature distribution within the boundary layer. Increase in the slip velocity enhances the rate of heat transfer whereas thermal slip reduces the rate of heat transfer.
Numerical and experimental investigations to describe the mode of operation and effectivity of large surface high sensitive SPNDs (Self-Powered-Neutron-Detectors)
International Nuclear Information System (INIS)
Al-Dabagh, D.
First a computer model for the parametric calculation of the (n,γ)-reaction rates in the emitter of the SPND was developed under use of the Monte-Carlo Program KENO II. To determine the escape-probability of the electrons produced via Compton- or photoelectric effect by the emitter as well as from the surrounding isolator, a new Monte-Carlo-Program was implemented under consideration of the Klein-Nishina-formula and the energy-range relationships for electrons. The approximate calculations performed for the electrons produced in the isolator show that the 'isolator flux' can give an important contribution to the total signal of the SPND. Subsequently with this program system an optimization of the neutron sensitivity was performed by a suitable choice of geometry (emitter thickness, isolator thickness). For a specially built large surface SPND with Gadolinium-emitter the neutron sensitivity was calculated. These results were checked by an In-Pile-Experiment in the FRJ-1 reactor. Very good agreement was found. The detector was also shown to exhibit excellent linearity and showed also the expected enhanced sensitivity. (orig./HP) [de
The enhancing power of iodide on corrosion prevention of mild steel in the presence of a synthetic-soluble Schiff-base: Electrochemical and surface analyses
International Nuclear Information System (INIS)
Lashgari, Mohsen; Arshadi, Mohammad-Reza; Miandari, Somaieh
The inhibitory action of N,N'-1,3-propylen-bis(3-methoxysalicylidenimine) {PMSI} on mild steel corrosion in sulfuric acid medium was investigated through electrochemical methods and evaluations based on infrared spectroscopy and scanning electron micrographs. The studies revealed that the molecule is a good mixed-type inhibitor (mostly anodic), acts as a multi-dentate ligand and repels the corrosive agents by hydrophobic forces. Its adsorption on metal surface has a physicochemical nature and obeys the Langmuir isotherm. At a critical (optimum) concentration, an anomalous inhibitory behavior was observed and interpreted at microscopic level by means of desorption/adsorption process and horizontal ↔vertical hypothesis. The addition of iodide into acid moreover causes a synergistic influence, a substantial enhancement on inhibitory performance. Finally, using isolated inhibitor calculations at B3LYP/6-31G + (d,p) level of theory, the equilibrium geometry of PMSI was determined and the energy required for hindrance avoidance was predicted.
Eccles, William
Pragmatic Power is focused on just three aspects of the AC electrical power system that supplies and moves the vast majority of electrical energy nearly everywhere in the world: three-phase power systems, transformers, and induction motors. The reader needs to have had an introduction to electrical circuits and AC power, although the text begins with a review of the basics of AC power. Balanced three-phase systems are studied by developing their single-phase equivalents. The study includes a look at how the cost of ""power"" is affected by reactive power and power factor. Transformers are cons
International Nuclear Information System (INIS)
Bacon, H.; Valentine, J.
The subject is covered in chapters, entitled: radiation (hazards associated with nuclear power production); wastes (radioactive wastes); accidents (actual and postulated, resulting in the release of radiation); the FBR and the plutonium cycle; costs (economics of nuclear power); spent fuel transport; civil liberties; doing without nuclear power (UK power demand; low energy strategy; energy policy; government policies; alternative energy sources). (U.K.)
International Nuclear Information System (INIS)
Murakami, T.
While the power consumption of CAMAC and VME modules is less than 40 watts per module and that of TKO and FASTBUS is much more, the former group consumes twice as much power per unit surface area as the latter group. The area occupied by components amounts to 60 percent of the total board area in TKO Super Controller Head Module and to 83 percent in VME Memory Partner module. Such a high packing density results in a high power density, and cooling of such modules becomes difficult. Despite these, such electronics systems with very high packing density are expected to become popular. The present report summarizes studies on various aspects of high power systems. The studies cover the cooling, routing power, and resistance to fire. A forced air cooling unit for TKO is developed. It serves to achieve a very high air flow rate for cooling, but high power systems would require better temperature compensation than other systems since one cannot expect a uniform ambient temperature distribution to be achieved over the board surface. It might even prohibit high resolution circuits to function to full capacity. Another study is made on a backplane that can supply much more current than conventional ones. A special power connector is developed which can supply currents up to 50 ampere. (N.K.)
International Nuclear Information System (INIS)
Hancox, R.
The principles of fusion power, and its advantages and disadvantages, are outlined. Present research programmes and future plans directed towards the development of a fusion power reactor, are summarized. (U.K.)
DEFF Research Database (Denmark)
Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede
is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....
DEFF Research Database (Denmark)
The social sciences have many different understandings of 'normative power', but in European Union (EU) studies normative power has three particular meanings. The first meaning of normative power is its emphasis on normative theory, that is, how we judge and justify truth claims in social science....... The second meaning of normative power is as a form of power that is ideational rather than material or physical. The third meaning of normative power is as a characterisation of an ideal type of international actor. Empirical studies of normative forms of power have analysed both the causal and constitutive...... effects of EU relations with the world in areas ranging from inter-regional relations, through traditional diplomacy, to environmental politics. Research areas of particular interest include the study of the interplay between physical, material and normative forms of power, as well as the constitutive...
DEFF Research Database (Denmark)
Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede
The global electrical energy consumption is still rising and there is an urgent demand to increase the power capacity. It is expected that the power capacity has to be doubled within 20 years. The production, distribution and use of energy should be as efficient as possible and incentives to save...... energy at the end-user should also be set up. Deregulation of energy has in the past lowered the investment in larger power plants, which means the need for new electrical power sources will be high in the near future. Two major technologies will play important roles to solve the future problems. One...... is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...
DEFF Research Database (Denmark)
Angjelichinoski, Marko; Stefanovic, Cedomir; Popovski, Petar
A standard way to realize communication in microgrid control is to use an external communication network, such as modems for wireless or power-line communication, whose implementation may be inefficient in terms of deployment cost, complexity, and system stability. In this chapter we present...... a communication solution, denoted as power talk, which is solely based on the use of the existing microgrid power equipment (i.e., power electronics and buses). The pivotal idea is to modulate information in the power-related parameters of the microgrid buses by use of the flexibility of power electronic...... interfaces. The focus of the chapter is on the design of power talk solutions for DC microgrids with droop control. Specifically, the chapter presents the power talk implementation through modification of the droop parameters of the primary control loop, and investigates the design of modulation schemes...
Indian Academy of Sciences (India)
December 2007. They cover a wide spectrum of areas from power supplies to power system applications. The first four papers are related to power converter topologies. Lakshminarasamma &. Ramanarayanan describe the modelling and design of a family of soft transition converters, while Bhardwaj et al discuss reduction ...
Indian Academy of Sciences (India)
Table of contents. PowerPoint Presentation · Slide 2 · Receptor-mediated endocytosis · Slide 4 · Publications – Direct therapeutic approaches · Importance of ECM recognition · Publications – ECM interactions · Slide 8 · L. donovani, when attached to the macrophage surface, behaves like any other microbe which are killed ...
Cubesat SEP Power Module, Phase I
National Aeronautics and Space Administration — Today's CubeSats are inherently power limited due to their small size and available surface area. Today's CubeSats offer <100W of available power. This limits...
International Nuclear Information System (INIS)
Porter, Arthur.
This chapter of the final report of the Royal Commission on Electric Power Planning in Ontario updates its interim report on nuclear power in Ontario (1978) in the light of the Three Mile Island accident and presents the commission's general conclusions and recommendations relating to nuclear power. The risks of nuclear power, reactor safety with special reference to Three Mile Island and incidents at the Bruce generating station, the environmental effects of uranium mining and milling, waste management, nuclear power economics, uranium supplies, socio-political issues, and the regulation of nuclear power are discussed. Specific recommendations are made concerning the organization and public control of Ontario Hydro, but the commission concluded that nuclear power is acceptable in Ontario as long as satisfactory progress is made in the disposal of uranium mill tailings and spent fuel wastes. (LL)
Test surfaces useful for calibration of surface profilometers
Yashchuk, Valeriy V; McKinney, Wayne R; Takacs, Peter Z
The present invention provides for test surfaces and methods for calibration of surface profilometers, including interferometric and atomic force microscopes. Calibration is performed using a specially designed test surface, or the Binary Pseudo-random (BPR) grating (array). Utilizing the BPR grating (array) to measure the power spectral density (PSD) spectrum, the profilometer is calibrated by determining the instrumental modulation transfer.
International Nuclear Information System (INIS)
Rabin, J.M.
A mathematically rigorous notion of supermanifold is presented and used to develop the theory of super Riemann surfaces. Super Riemann surfaces describe superconformal equivalence classes of supergravity geometries in two dimensions and therefore provide a powerful formalism for studying fermionic string theory. They also provide a convenient description of spin structures and half-forms on ordinary Riemann surfaces. I prove the uniformization theorem for super Riemann surfaces, determine the dimension and global structure of super Teichmueller space, and show that the super modular group is isomorphic to the ordinary modular (mapping class) group. Quasisuperconformal mappings and the super Beltrami equations are briefly discussed. 32 refs
Stockholm Power Tech. Power systems
International Nuclear Information System (INIS)
The proceedings from this symposium is presented in six volumes: Invited speakers' sessions; Power systems; Power electronics; High-voltage technology; Electrical machines and drives; and Information and control systems. This report covers the power systems volume. Separate abstracts have been prepared for 141 of the 145 papers in this volume
Stockholm Power Tech. Power systems
Energy Technology Data Exchange (ETDEWEB)
The proceedings from this symposium is presented in six volumes: Invited speakers` sessions; Power systems; Power electronics; High-voltage technology; Electrical machines and drives; and Information and control systems. This report covers the power systems volume. Separate abstracts have been prepared for 141 of the 145 papers in this volume
Fabrication Processes for Surface-Emitting via External 45-DEGREE Reflectors, High-Power via Arrayed Ridge - Single-Mode Phase-Locked Aluminum Gallium Arsenide/gallium Arsenide Semiconductor Laser Sources.
Porkolab, Gyorgy Arpad
The fabrication of monolithically integrated configurations of semiconductor lasers incorporating multiple functions is still an open issue today in engineering. A useful set of functions to integrate are: surface-emitting, high -power, phase-locked, single-mode, and collimated laser beam output. In this work new materials and advanced fabrication processes are developed for integrating the first four of the five functions listed. The interest in semiconductor lasers is due to their greater than 90% internal quantum efficiency in converting current-flux to photon-flux, their small size and weight, and their wavelength range from 400 to 1,550 nm. Multitudes of applications are possible for semiconductor laser sources ranging from the low-volume market of satellite-based communications systems to the high-volume market of image display screens. Semimetallic amorphous carbon (SMAC) thin film is introduced as an etch mask for chemically assisted ion beam etching (CAIBE) resulting in smooth etched facets in AlGaAs/GaAs at normal- and 45-degrees- incidence angles. A self-aligned etch technique is introduced using 4 separate photoresist selector-masks on top of a fixed SMAC master -mask on top of the AlGaAs/GaAs substrate to perform 4 separate CAIBE etches at 3 different angles and to 3 different depths to create self-aligned 3-dimensional microstructures of 1.3-μm deep ridge waveguides (RWG), 6-μm deep laser facets, and 11- μm long back-to-back 45-degree reflectors arranged in 3 by 100 arrays. Trenches on topside and underside of laser facets are introduced to deflect current away from laser facets. Silicon-rich nitro-oxide thin film is introduced as triple-use encapsulation to provide chemical passivation of AlGaAs/GaAs, optical anti-reflection coating by being refractive-index matched to AlGaAs/GaAs, and electrical insulation. A pincer-action sample-holder for CAIBE is introduced allowing samples to heat up by ion beam heating. Various surface preparations
Positron annihilation near fractal surfaces
International Nuclear Information System (INIS)
Lung, C.W.; Deng, K.M.; Xiong, L.Y.
A model for positron annihilation in the sub-surface region near a fractal surface is proposed. It is found that the power law relationship between the mean positron implantation depth and incident positron energy can be used to measure the fractal dimension of the fractal surface in materials. (author). 10 refs, 2 figs
Power Converters and Power Quality
Kahle, K
This paper discusses the subject of power quality for power converters. The first part gives an overview of most of the common disturbances and power quality issues in electrical networks for particle accelerators, and explains their consequences for accelerator operation. The propagation of asymmetrical network disturbances into a network is analysed. Quantitative parameters for network disturbances in a typical network are presented, and immunity levels for users' electrical equipment are proposed. The second part of this paper discusses the technologies and strategies used in particle accelerator networks for power quality improvement . Particular focus is given to networks supplying loads with cycling active and reactive power
Electrical power systems for Mars
Giudici, Robert J.
Electrical power system options for Mars Manned Modules and Mars Surface Bases were evaluated for both near-term and advanced performance potential. The power system options investigated for the Mission Modules include photovoltaics, solar thermal, nuclear reactor, and isotope power systems. Options discussed for Mars Bases include the above options with the addition of a brief discussion of open loop energy conversion of Mars resources, including utilization of wind, subsurface thermal gradients, and super oxides. Electrical power requirements for Mission Modules were estimated for three basic approaches: as a function of crew size; as a function of electric propulsion; and as a function of transmission of power from an orbiter to the surface of Mars via laser or radio frequency. Mars Base power requirements were assumed to be determined by production facilities that make resources available for follow-on missions leading to the establishment of a permanently manned Base. Requirements include the production of buffer gas and propellant production plants.
International Nuclear Information System (INIS)
King, P.
Written from the basis of neutrality, neither for nor against nuclear power this book considers whether there are special features of nuclear power which mean that its development should be either promoted or restrained by the State. The author makes it dear that there are no easy answers to the questions raised by the intervention of nuclear power but calls for openness in the nuclear decision making process. First, the need for energy is considered; most people agree that energy is the power to progress. Then the historicalzed background to the current position of nuclear power is given. Further chapters consider the fuel cycle, environmental impacts including carbon dioxide emission and the greenhouse effect, the costs, safety and risks and waste disposal. No conclusion either for or against nuclear power is made. The various shades of opinion are outlined and the arguments presented so that readers can come to their own conclusions. (UK)
International Nuclear Information System (INIS)
Kennedy, Tom
Discusses the fight over the diminishing supply of fossil fuels and how there could be an unlimited, clean and politically free source of power just over the horizon. Fusion was discovered as a much better, inexhaustable supply of power, it only takes a few atoms to fuse for fusion to take off. Fusion once started will continue until all the fuel is exhausted. It is expected, that with the current rate of progess, in fifty years time scientists will achieve practical fusion power
Wörman, A.; Lindström, G.; Riml, J.
Although the potential energy of surface water is a small part of Earth's energy budget, this highly variable physical property is a key component in the terrestrial hydrologic cycle empowering geomorphological and hydrological processes throughout the hydrosphere. By downscaling of the daily hydrometeorological data acquired in Sweden over the last half-century this study quantifies the spatial and temporal distribution of the dominating energy components in terrestrial hydrology, including the frictional resistance in surface water and groundwater as well as hydropower. The energy consumed in groundwater circulation was found to be 34.6 TWh/y or a heat production of approximately 13% of the geothermal heat flux. Significant climate driven, periodic fluctuations in the power of runoff, stream flows and groundwater circulation were revealed that have not previously been documented. We found that the runoff power ranged from 173 to 260 TWh/y even when averaged over the entire surface of Sweden in a five-year moving window. We separated short-term fluctuations in runoff due to precipitation filtered through the watershed from longer-term seasonal and climate driven modes. Strong climate driven correlations between the power of runoff and climate indices, wind and solar intensity were found over periods of 3.6 and 8 years. The high covariance that we found between the potential energy of surface water and wind energy implies significant challenges for the combination of these renewable energy sources.
Amphoteric surface active agents
Eissa, A.M. F.
2-[trimethyl ammonium, triethyl ammonium, pyridinium and 2-amino pyridinium] alkanoates, four series of surface active agents containing carbon chain C12, C14, C16 and C18carbon atoms, were prepared. Their structures were characterized by microanalysis, infrared (IR) and nuclear magnetic resonance (NMR). Surface and interfacial tension, Krafft point, wetting time, emulsification power, foaming height a...
Indian Academy of Sciences (India)
Kishore Chatterjee
Power electronics plays an important role in the processing, conditioning and utilization of electric power. From ubiquitous ... An induction motor drive based on a modular multilevel converter (MMC) is presented ... dynamic voltage restorer and the control of an induction motor drive having an active front end converter.
International Nuclear Information System (INIS)
Abd Khalik Wood
This chapter discuss on nuclear power and its advantages. The concept of nucleus fission, fusion, electric generation are discussed in this chapter. Nuclear power has big potential to become alternative energy to substitute current conventional energy from coal, oil and gas
Indian Academy of Sciences (India)
Kishore Chatterjee
reference material for power electronics engineers, students and academicians. We thank the editors of Sadhana for inviting us to guest-edit this special issue on power electronics. July 2017. KISHORE CHATTERJEE. Department of Electrical Engineering,. Indian Institute of Technology,. Bombay, Powai, Mumbai 400076, ...
Indian Academy of Sciences (India)
Such real time models are extremely important, as they can be included in real time simulation of sys- tems to evolve control schemes for the converters as well as to study the effect on the power system. In view of the control possibilities offered by the use of power converters and the newly emerging applications, there has ...
Determinación in vitro de los patrones de inducción de una endo-xilanasa (E.C.126.96.36.199 secretada por Fusarium oxysporum f.sp. dianthi. Purificación y caracterización parcial
Directory of Open Access Journals (Sweden)
Sixta Tulia Martinez
Full Text Available Al hacer un ensayo in vitro, la enzimaxilanasa secretada por el patógeno Fusariumoxysporum f.sp. dianthi se induceen presencia de pared celular de tallo yraíz de clavel de variedades tolerantesy resistentes. Se observa un comportamientodiferencial según el órgano y lavariedad, que demuestra la influencia,en la inducción, de las características delhospedero.La enzima se purifica parcialmenteutilizando cromatografías de intercambiocatiónico, aniónico y tamiz molecular. Lacaracterización bioquímica presenta lossiguientes valores: masa molecular 38,8kDa, temperatura y pH óptimo 35 0Cy 10, respectivamente, Kmap = 0,2 mg/mL, Vmaxap = 500 U/mg.La presencia de oligogalacturónidoscomo productos de hidrólisis detectadoscon una cromatografía en capa delgadapermite clasificar la enzima como unaendoxilanasa.La enzima retiene el 50 % de su estabilidada pH muy alcalino, y presentaalta termoestabilidad en un intervalo detemperatura entre 30 y 80 0C.
International Nuclear Information System (INIS)
The key element of our pulsed power program is concentration of power in time and space by suppression of breakdown in dielectrics and in vacuum. Magnetically insulated vacuum transmission lines and magnetic suppression of insulator flashover have continued as the main reserch directions. Vacuum insulated line studies at Physics International have been expanded and a test bed at Sandia, called MITE (Magnetically Insulated Transmission Experiment), is under development. The choice for the baseline EBFA design will depend on the outcome of these studies and should be made in July 1977. The slow and intermediate speed pulsed power approaches to EBFA will be based on Proto I and Proto II results and several of the projected EBFA subsystems are presently being tested in Proto II. A further stage of power concentration, within the vacuum diode itself, would considerably ease the burden on dielectrics; methods of power multiplication involving magnetically imploded plasmas are being considered and tests have begun using the Ripple III apparatus
Modeling the effects of ultrasound power and reactor dimension on the biodiesel production yield: Comparison of prediction abilities between response surface methodology (RSM) and adaptive neuro-fuzzy inference system (ANFIS)
International Nuclear Information System (INIS)
Mostafaei, Mostafa; Javadikia, Hossein; Naderloo, Leila
Biodiesel is as an alternative petro-diesel fuel produced from the renewable resources. The use of novel technologies such as ultrasound technology for biodiesel production intensifies the reaction and reduces the process cost. The present study is aimed to evaluate and compare the prediction and simulating efficiency of the response surface methodology (RSM) and adaptive Neuro-fuzzy inference system (ANFIS) approaches for modeling the transesterification yield achieved in ultrasonic reactor. The influence of independent variables (reactor diameter, liquid height and ultrasound intensity) on the conversion of fatty acid methyl esters (FAME) was investigated by Box-Behnken design of RSM and two ANFIS approaches (hybrid and back-propagation optimization methods). All models were compared statistically based on the training and validation data set by the coefficient of determination (R2), root mean squares error (RMSE), mean absolute percentage error (MAPE), mean absolute error (MAE) and mean relative percent deviation (MRPD). The calculated R2 for RSM and two ANFIS models were 0.9669, 0.9812 and 0.9808, respectively. All models indicated good predictions, however, the ANFIS models were more precise compared to the RSM model, which proves that the ANFIS is a powerful tool for modeling and optimizing FAME production in ultrasound reactor. - Highlights: • The ultrasound assisted FAME conversion was modelled using RSM and ANFIS approaches. • The scatter diagrams indicate the models accurately predicted the reaction yield. • The ANFIS model (hybrid) has higher R 2 (0.9812) compared to the RSM model. • The predicted deviations and residual values are relatively small for ANFIS model. • ANFIS model was more accurate for predicting ultrasound assisted FAME conversion.
International Nuclear Information System (INIS)
Nunez, Anibal D.
In the second half of twentieth century, nuclear power became an industrial reality. Now the operating 433 power plants, the 37 plants under construction, near 9000 years/reactor with only one serious accident with emission of radioactive material to the environment (Chernobyl) show the maturity of this technology. Today nuclear power contribute a 17% to the global generation and an increase of 75 % of the demand of electricity is estimated for 2020 while this demand is expected to triplicate by 2050. How this requirement can be satisfied? All the indicators seems to demonstrate that nuclear power will be the solution because of the shortage of other sources, the increase of the prices of the non renewable fuels and the scarce contribution of the renewable ones. In addition, the climatic changes produced by the greenhouse effect make even more attractive nuclear power. The situation of Argentina is analyzed and compared with other countries. The convenience of an increase of nuclear power contribution to the total national generation seems clear and the conclusion of the construction of the Atucha II nuclear power plant is recommended
International Nuclear Information System (INIS)
The committee concludes that the nature of the proliferation problem is such that even stopping nuclear power completely could not stop proliferation completely. Countries can acquire nuclear weapons by means independent of commercial nuclear power. It is reasonable to suppose if a country is strongly motivated to acquire nuclear weapons, it will have them by 2010, or soon thereafter, no matter how nuclear power is managed in the meantime. Unilateral and international diplomatic measures to reduce the motivations that lead to proliferation should be high on the foreign policy agenda of the United States. A mimimum antiproliferation prescription for the management of nuclear power is to try to raise the political barriers against proliferation through misuse of nuclear power by strengthening the Non-Proliferation Treaty, and to seek to raise the technological barriers by placing fuel-cycle operations involving weapons-usable material under international control. Any such measures should be considered tactics to slow the spread of nuclear weapons and thus earn time for the exercise of statesmanship. The committee concludes the following about technical factors that should be considered in formulating nuclear policy: (1) rate of growth of electricity use is a primary factor; (2) growth of conventional nuclear power will be limited by producibility of domestic uranium sources; (3) greater contribution of nuclear power beyond 400 GWe past the year 2000 can only be supported by advanced reactor systems; and (4) several different breeder reactors could serve in principle as candidates for an indefinitely sustainable source of energy
DEFF Research Database (Denmark)
Liu, Hongpeng; Yang, Yongheng; Loh, Poh Chiang
In this paper, a novel communication strategy called Power Talk is introduced to realize the power line communication among the Voltage Source Converters (VSC) of DC MicroGrids (MGs). Each VSC transmits information by changing the control parameters, and receives information by observing the local...... output power. By using common coding schemes, which transform the DC MGs in some familiar communication channels, some important communication challenges can be addressed, such as random load variations and VSCs switching, as it do not need a separate communication channel. For this purpose, two multiple...
DEFF Research Database (Denmark)
Stefanovic, Cedomir; Popovski, Petar; Angjelichinoski, Marko
We introduce a novel communication strategy for DC Micro Grids (MGs), termed power talk, in which the devices communicate by modulating the power levels in the DC bus. The information is transmitted by varying the parameters that the MG units use to control the level of the common bus voltage......, while it is received by processing the bus measurements that units perform. This implies that the communication does not require a dedicated modem, but instead it is piggybacked on top of the power electronics. The communication is challenged by the random fluctuations of the voltage level due...
David Waller and Alan McDonald ask whether a nuclear renaissance can be predicted; Judith M. Greenwald discusses keeping the nuclear power option open; Paul Mobbs considers the availability of uranium and the future of nuclear energy.
DEFF Research Database (Denmark)
Galster, Kjeld
Power Preservation (Abstract) In the 17th century, just as today, coalitions needed 'lead nations'. This was assumed to be a power with great military and economic potentials, and Denmark endeavoured to act as such a leader in the Thirty Years War from 1626 to 28. The results were not encouraging...... in the military field and they were disastrous as far as fiscal matters were concerned. Sweden took over the leadership of the protestant side and she took over Denmark's place amongst the great powers of the Baltic Region. From that time onwards, Danish influence and options on the international stage gradually...... declined. Thus, Denmark of the 17th century is not to be counted amongst the great powers, but since Christian V's accession to the throne in 1670 Denmark-Norway has developed into one of Europe's most highly militarised states. Apart from a permanently combat ready navy, the country maintains a standing...
Maxwell Laboratories capacitor charging power supply is the first commercial spinoff from the NASA CCDS program - a consortia of industries and government establishments to accelerate development of ground and space based commercial applications of NASA technology. The power supply transforms and conditions large voltages to charge capacitors used in x-ray sources, medical accelerators, etc. It is lighter, more reliable, more compact and efficient. Originally developed for space lasers, its commercial potential was soon recognized.
Introduction to electrical power and power electronics
Patel, Mukund R
Power Generation, Distribution, and Utilization AC Power Fundamentals Common Aspects of Power Equipments AC Generator AC and DC Motors Transformer Power Cable Power Distribution Fault Current Analysis System ProtectionEconomic Use of PowerElectrochemical BatteryPower Electronics and Motor Drives Power Electronics Devices DC-DC Converters AC-DC-AC Converters Variable-Frequency Drives Quality of Power Power Converter CoolingAppendixIndex
International Nuclear Information System (INIS)
Gipe, P.
This book is a translation of the edition published in the USA under the title of ''wind power: renewable energy for home, farm and business''. In the wake of mass blackouts and energy crises, wind power remains a largely untapped resource of renewable energy. It is a booming worldwide industry whose technology, under the collective wing of aficionados like author Paul Gipe, is coming of age. Wind Power guides us through the emergent, sometimes daunting discourse on wind technology, giving frank explanations of how to use wind technology wisely and sound advice on how to avoid common mistakes. Since the mid-1970's, Paul Gipe has played a part in nearly every aspect of wind energy development from installing small turbines to promoting wind energy worldwide. As an American proponent of renewable energy, Gipe has earned the acclaim and respect of European energy specialists for years, but his arguments have often fallen on deaf ears at home. Today, the topic of wind power is cropping up everywhere from the beaches of Cape Cod to the Oregon-Washington border, and one wind turbine is capable of producing enough electricity per year to run 200 average American households. Now, Paul Gipe is back to shed light on this increasingly important energy source with a revised edition of Wind Power. Over the course of his career, Paul Gipe has been a proponent, participant, observer, and critic of the wind industry. His experience with wind has given rise to two previous books on the subject, Wind Energy Basics and Wind Power for Home and Business, which have sold over 50,000 copies. Wind Power for Home and Business has become a staple for both homeowners and professionals interested in the subject, and now, with energy prices soaring, interest in wind power is hitting an all-time high. With chapters on output and economics, Wind Power discloses how much you can expect from each method of wind technology, both in terms of energy and financial savings. The book updated models
Concentrated solar power: an overview
International Nuclear Information System (INIS)
Najam, Z.; Khan, M.I.
Solar thermal power is a relatively new technology and a fine arrangement for the provision of Electrical Energy and Clean Energy in general .The concentrated solar offers a viable option for the Sunny Zones of the world. The efficiency of the System depends on a few factors like Area, Intensity of Sunlight, Type of receiver, Hybridisation etc. Solar Thermal Systems employ lenses or mirrors to focus a large area of sunlight onto a small area. Electrical power is produced when the concentrated light is impugned onto photovoltaic cell made surfaces or used to heat a transfer fluid for a conventional power plant. In this paper we give a brief overview of a baseline Solar Thermal Power Plant, Technological details, Cost and Benefit analysis, a glimpse of solar thermal power and future of solar thermal power. (author)
DEFF Research Database (Denmark)
Tønder, Lars
Inspired by the growing attention to the politics of comedy in the United States and elsewhere, this article asks what it would mean to think critically about relations of power mobilized through cheerfulness, humor, and laughter. The article shows that existing answers to this question are tainted...... by skepticism about the enduring contributions of comic acts, and it then goes on to suggest that we turn to an alternative trajectory in democratic theory, one that encourages us to focus on the empowering and pluralizing potential embedded in what I name "comic power." The wager is that attention...... to the potential embedded in this power can give us new traction on the conditions of democracy more broadly understood. To show this, the article draws on two rarely paired resources—Spinoza's philosophy of immanence and Dave Chappelle's critique of racial discrimination—placing both of them in conversation...
Energy Technology Data Exchange (ETDEWEB)
Walbridge, E.W.
A laser satellite power system (SPS) converts solar power captured by earth-orbiting satellites into electrical power on the earth's surface, the satellite-to-ground transmission of power being effected by laser beam. The laser SPS may be an alternative to the microwave SPS. Microwaves easily penetrate clouds while laser radiation does not. Although there is this major disadvantage to a laser SPS, that system has four important advantages over the microwave alternative: (1) land requirements are much less, (2) radiation levels are low outside the laser ground stations, (3) laser beam sidelobes are not expected to interfere with electromagnetic systems, and (4) the laser system lends itself to small-scale demonstration. After describing lasers and how they work, the report discusses the five lasers that are candidates for application in a laser SPS: electric discharge lasers, direct and indirect solar pumped lasers, free electron lasers, and closed-cycle chemical lasers. The Lockheed laser SPS is examined in some detail. To determine whether a laser SPS will be worthy of future deployment, its capabilities need to be better understood and its attractiveness relative to other electric power options better assessed. First priority should be given to potential program stoppers, e.g., beam attenuation by clouds. If investigation shows these potential program stoppers to be resolvable, further research should investigate lasers that are particularly promising for SPS application.
International Nuclear Information System (INIS)
Baker, A.C.
This book describes how large tides develop in particular places and how the energy could be extracted by building suitable barrages. The principal features of a barrage and possible methods of operation are described in detail. Although a tidal power barrage would be non-polluting, the resulting changes in the tidal regime would have important environmental effects. These are discussed together with the economics of tidal power. Methods of assessing the likely cost of electricity from any site are set out and applied to possible sites around the world. (author)
Showstack, Randy
Three new reports commissioned by the Pew Center on Global Climate Change examine the electric power sectors in Argentina, Brazil, and China, and the potential impact that energy use in each country has on climate change.In 1999, Argentina voluntarily agreed to lower its greenhouse gas emissions to 2 10% below projected emissions for 2012. The report looks at additional steps that could further reduce emissions, including adopting policies that favor renewable energy sources and nuclear power, and increasing energy efficiency by end-users.
Dierkes, Ulrich; Sauvigny, Friedrich; Jakob, Ruben; Kuster, Albrecht
Minimal Surfaces is the first volume of a three volume treatise on minimal surfaces (Grundlehren Nr. 339-341). Each volume can be read and studied independently of the others. The central theme is boundary value problems for minimal surfaces. The treatise is a substantially revised and extended version of the monograph Minimal Surfaces I, II (Grundlehren Nr. 295 & 296). The first volume begins with an exposition of basic ideas of the theory of surfaces in three-dimensional Euclidean space, followed by an introduction of minimal surfaces as stationary points of area, or equivalently
Nuclear power systems for Lunar and Mars exploration
International Nuclear Information System (INIS)
Sovie, R.J.; Bozek, J.M.
Initial studies of a variety of mission scenarios for the new Space Exploration Initiative, and the technologies necessary to enable or significantly enhance them, have identified the development of advanced space power systems - whether solar, chemical or nuclear - to be of prime importance. Lightweight, compact, reliable power systems for planetary rovers and a variety of surface vehicles, utility surface power, and power for advanced propulsion systems were identified as critical needs for these missions. This paper discusses these mission scenarios, the concomitant power system requirements; the power system options considered and identifies the significant potential benefits of nuclear power for meeting the power needs of the above applications
International Nuclear Information System (INIS)
This road-map proposes by the Group Total aims to inform the public on the wind power. It presents the principles, the technology takes off, its applications and technology focus, the global market trends and the outlooks and Total commitments in the domain. (A.L.B.)
African Journals Online (AJOL)
Atomic Power. By Denis Taylor: Dr. Taylor was formerly Chief UNESCO Advisor at the University. College, Nairobi, Kenya and is now Professor of Electrical Engineering in the Uni- versity of Strachlyde, Scotland. He is a leading scientist in the electronics field. He was among the British scientists who developed radar during ...
Energy Technology Data Exchange (ETDEWEB)
Marsh, A. [Plug Power Inc., New York, NY (United States)
This presentation described Plug Power's GenDrive hydrogen fuel cell unit that supplies the power needs for folk lift trucks used in high-throughput distribution and high-volume manufacturing operations. The system offers an alternative to lead acid batteries, providing maximum performance at all times during use. The system is particularly useful in the material handling industry, where the revenue generated is based on operator uptime and lift truck productivity. The use of the system allows customers to reduce operational costs and expand valuable floor space by eliminating batteries and associated recharging infrastructure. Fuel cell units also reduce the wear on truck motors. Truck operators can easily and safely refuel at hydrogen fueling stations in 1-5 minutes. GenDrive works with all major OEM lift trucks, making the transition seamless. Commercial customers are investing in this solution to improve their current operations. In 2008, Plug Power sold to Wal-Mart, Bridgestone Firestone and Nestle. Most notably, Central Grocers purchased 220 fuel cell units for a new greenfield distribution center. Plug Power currently has more than 380 systems in operation.
Modulation of human dermal microvascular endothelial cell and human gingival fibroblast behavior by micropatterned silica coating surfaces for zirconia dental implant applications
International Nuclear Information System (INIS)
Laranjeira, Marta S; Carvalho, Ângela; Ferraz, Maria Pia; Monteiro, Fernando Jorge; Pelaez-Vargas, Alejandro; Hansford, Derek; Coimbra, Susana; Costa, Elísio; Santos-Silva, Alice; Fernandes, Maria Helena
Dental ceramic implants have shown superior esthetic behavior and the absence of induced allergic disorders when compared to titanium implants. Zirconia may become a potential candidate to be used as an alternative to titanium dental implants if surface modifications are introduced. In this work, bioactive micropatterned silica coatings were produced on zirconia substrates, using a combined methodology of sol–gel processing and soft lithography. The aim of the work was to compare the in vitro behavior of human gingival fibroblasts (HGFs) and human dermal microvascular endothelial cells (HDMECs) on three types of silica-coated zirconia surfaces: flat and micropatterned (with pillars and with parallel grooves). Our results showed that cells had a higher metabolic activity (HGF, HDMEC) and increased gene expression levels of fibroblast-specific protein-1 (FSP-1) and collagen type I (COL I) on surfaces with pillars. Nevertheless, parallel grooved surfaces were able to guide cell growth. Even capillary tube-like networks of HDMEC were oriented according to the surface geometry. Zirconia and silica with different topographies have shown to be blood compatible and silica coating reduced bacteria adhesion. All together, the results indicated that microstructured bioactive coating seems to be an efficient strategy to improve soft tissue integration on zirconia implants, protecting implants from peri-implant inflammation and improving long-term implant stabilization. This new approach of micropatterned silica coating on zirconia substrates can generate promising novel dental implants, with surfaces that provide physical cues to guide cells and enhance their behavior. (paper)
Modulation of human dermal microvascular endothelial cell and human gingival fibroblast behavior by micropatterned silica coating surfaces for zirconia dental implant applications
Laranjeira, Marta S.; Carvalho, Ângela; Pelaez-Vargas, Alejandro; Hansford, Derek; Ferraz, Maria Pia; Coimbra, Susana; Costa, Elísio; Santos-Silva, Alice; Fernandes, Maria Helena; Monteiro, Fernando Jorge
Dental ceramic implants have shown superior esthetic behavior and the absence of induced allergic disorders when compared to titanium implants. Zirconia may become a potential candidate to be used as an alternative to titanium dental implants if surface modifications are introduced. In this work, bioactive micropatterned silica coatings were produced on zirconia substrates, using a combined methodology of sol-gel processing and soft lithography. The aim of the work was to compare the in vitro behavior of human gingival fibroblasts (HGFs) and human dermal microvascular endothelial cells (HDMECs) on three types of silica-coated zirconia surfaces: flat and micropatterned (with pillars and with parallel grooves). Our results showed that cells had a higher metabolic activity (HGF, HDMEC) and increased gene expression levels of fibroblast-specific protein-1 (FSP-1) and collagen type I (COL I) on surfaces with pillars. Nevertheless, parallel grooved surfaces were able to guide cell growth. Even capillary tube-like networks of HDMEC were oriented according to the surface geometry. Zirconia and silica with different topographies have shown to be blood compatible and silica coating reduced bacteria adhesion. All together, the results indicated that microstructured bioactive coating seems to be an efficient strategy to improve soft tissue integration on zirconia implants, protecting implants from peri-implant inflammation and improving long-term implant stabilization. This new approach of micropatterned silica coating on zirconia substrates can generate promising novel dental implants, with surfaces that provide physical cues to guide cells and enhance their behavior.
CSIR Research Space (South Africa)
National Institute for Transport and Road
Full Text Available Rumble surfaces are intermittent short lengths of coarse-textured road surfacings on which vehicle tyres produce a rumbling sound. used in conjunction with appropriate roadsigns and markings, they can reduce accidents on rural roads by alerting...
International Nuclear Information System (INIS)
Garcia-Moliner, F.
Basic thermodynamics of a system consisting of two bulk phases with an interface. Solid surfaces: general. Discussion of experimental data on surface tension and related concepts. Adsorption thermodynamics in the Gibbsian scheme. Adsorption on inert solid adsorbents. Systems with electrical charges: chemistry and thermodynamics of imperfect crystals. Thermodynamics of charged surfaces. Simple models of charge transfer chemisorption. Adsorption heat and related concepts. Surface phase transitions
Power Electronics Thermal Control (Presentation)
Energy Technology Data Exchange (ETDEWEB)
Narumanchi, S.
Thermal management plays an important part in the cost of electric drives in terms of power electronics packaging. Very promising results have been obtained by using microporous coatings and skived surfaces in conjunction with single-phase and two-phase flows. Sintered materials and thermoplastics with embedded fibers show significant promise as thermal interface materials, or TIMs. Appropriate cooling technologies depend on the power electronics package application and reliability.
Energy Technology Data Exchange (ETDEWEB)
Hodgson, P.
The question 'Do we really need nuclear power' is tackled within the context of Christian beliefs. First, an estimate is made of the energy requirements in the future and whether it can be got in conventional ways. The dangers of all the ways of supplying energy (eg coal mining, oil and gas production) are considered scientifically. Also the cost of each source and its environmental effects are debated. The consequences of developing a new energy source, as well as the consequences of not developing it, are considered. Decisions must also take into account a belief about the ultimate purpose of life, the relation of men to each other and to nature. Each issue is raised and questions for discussion are posed. On the whole the book comes down in favour of nuclear power.
International Nuclear Information System (INIS)
Anghaie, S.
Initiative, the Jupiter Icy Moons Orbiter (JIMO), the project PROMETHUS, and the Moon and Mars surface power project. A brief history, future prospect, and some technology challenges of space nuclear power and propulsion will be discussed
International Nuclear Information System (INIS)
Costen, R.; Humes, D.H.; Walker, G.H.; Williams, M.D.; Deyoung, R.J.
The objective was to compare a nuclear reactor-driven Sterling engine lunar base power source to a laser-to-electric converter with orbiting laser power station, each providing 1 MW of electricity to the lunar base. The comparison was made on the basis of total mass required in low-Earth-orbit for each system. This total mass includes transportation mass required to place systems in low-lunar orbit or on the lunar surface. The nuclear reactor with Sterling engines is considered the reference mission for lunar base power and is described first. The details of the laser-to-electric converter and mass are discussed. The next two solar-driven high-power laser concepts, the diode array laser or the iodine laser system, are discussed with associated masses in low-lunar-orbit. Finally, the payoff for laser-power beaming is summarized
Spacecraft Surface Charging Handbook
discharges however produce replacement currents that can be global. The local effect of punchthrough is illustrated by a small dipole model for the...St'rap I Farda or TEK7103 Scope Power Dipole -- Line tenna To To PA HP05000 and Spectrum X-Y Analyzer Plotter Figure 61. Test setup for surface...Testing Seminar, Los Angeles, CA, p. 77-82, 19817. Levadou, F., "Proprietes Electriques Des Materiaux." Space Environment: Prevention of Risks Related
International Nuclear Information System (INIS)
Carney, H.C.
An electric power generator of the type employing a nuclear heat source and a thermoelectric converter is described wherein a transparent thermal insulating medium is provided inside an encapsulating enclosure to thermally insulate the heat source and thermoelectric generator. The heat source, the thermoelectric converter, and the enclosure are provided with facing surfaces which are heat-reflective to a substantial degree to inhibit radiation of heat through the medium of the encapsulating enclosure. Multiple reflective foils may be spaced within the medium as necessary to inhibit natural convection of heat and/or further inhibit radiation
30 CFR 57.12017 - Work on power circuits.
... shall prevent the power circuits from being energized without the knowledge of the individuals working... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Work on power circuits. 57.12017 Section 57... Surface and Underground § 57.12017 Work on power circuits. Power circuits shall be deenergized before work...
Wang, Evelyn N; McCarthy, Matthew; Enright, Ryan; Culver, James N; Gerasopoulos, Konstantinos; Ghodssi, Reza
Surfaces having a hierarchical structure--having features of both microscale and nanoscale dimensions--can exhibit superhydrophobic properties and advantageous condensation and heat transfer properties. The hierarchical surfaces can be fabricated using biological nanostructures, such as viruses as a self-assembled nanoscale template.
DEFF Research Database (Denmark)
Brander, David
We study surfaces of constant positive Gauss curvature in Euclidean 3-space via the harmonicity of the Gauss map. Using the loop group representation, we solve the regular and the singular geometric Cauchy problems for these surfaces, and use these solutions to compute several new examples. We give...
Lusin, S
The power system for the on-detector electronics of the CMS Experiment comprises approximately 12000 low voltage channels, with a total power requirement of 1.1 MVA. The radiation environment inside the CMS experimental cavern combined with an ambient magnetic field (reaching up to 1.3 kGauss at the detector periphery) severely limit the available choices of low voltage supplies, effectively ruling out the use of commercial off-the-shelf DC power supplies. Typical current requirements at the CMS detector front end range from 1A-30A per channel at voltages ranging between 1.25V and 8V. This requires in turn that the final stage of the low voltage power supply be located on the detector periphery. Power to the CMS front-end electronics is stabilized by a 2 MVA uninterruptible power supply (UPS) located in a CMS surface building. This UPS isolates the CMS detector from disturbances on the local power grid and provides for 2 minutes of autonomy following a power failure, allowing for an orderly shutdown of detect...
Low Cost Radiator for Fission Power Thermal Control, Phase I
National Aeronautics and Space Administration — NASA Glenn Research Center (GRC) is developing fission power system technology for future space transportation and surface power applications. The early systems are...
Low Cost Radiator for Fission Power Thermal Control, Phase II
National Aeronautics and Space Administration — NASA GRC is developing fission power system technology for future space transportation and surface power applications. The early systems are envisioned in the 10 to...
Shown here is one of the first images taken by NASA's Phoenix Mars Lander of one of the octagonal solar panels, which opened like two handheld, collapsible fans on either side of the spacecraft. Beyond this view is a small slice of the north polar terrain of Mars. The successfully deployed solar panels are critical to the success of the 90-day mission, as they are the spacecraft's only means of replenishing its power. Even before these images reached Earth, power readings from the spacecraft indicated to engineers that the solar panels were already at work recharging the spacecraft's batteries. Before deploying the Surface Stereo Imager to take these images, the lander waited about 15 minutes for the dust to settle. This image was taken by the spacecraft's Surface Stereo Imager on Sol, or Martian day, 0 (May 25, 2008). The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.
Shown here is one of the first images taken by NASA's Phoenix Mars Lander of one of the octagonal solar panels, which opened like two handheld, collapsible fans on either side of the spacecraft. Beyond this view is a small slice of the north polar terrain of Mars. The successfully deployed solar panels are critical to the success of the 90-day mission, as they are the spacecraft's only means of replenishing its power. Even before these images reached Earth, power readings from the spacecraft indicated to engineers that the solar panels were already at work recharging the spacecraft's batteries. Before deploying the Surface Stereo Imager to take these images, the lander waited about 15 minutes for the dust to settle. This image was taken by the spacecraft's Surface Stereo Imager on Sol, or Martian day, 0 (May 25, 2008). This image has been geometrically corrected. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.
Surface heat flux feedback controlled impurity seeding experiments with Alcator C-Mod's high-Z vertical target plate divertor: performance, limitations and implications for fusion power reactors
Brunner, D.; Wolfe, S. M.; LaBombard, B.; Kuang, A. Q.; Lipschultz, B.; Reinke, M. L.; Hubbard, A.; Hughes, J.; Mumgaard, R. T.; Terry, J. L.; Umansky, M. V.; The Alcator C-Mod Team
The Alcator C-Mod team has recently developed a feedback system to measure and control surface heat flux in real-time. The system uses real-time measurements of surface heat flux from surface thermocouples and a pulse-width modulated piezo valve to inject low-Z impurities (typically N2) into the private flux region. It has been used in C-Mod to mitigate peak surface heat fluxes >40 MW m-2 down to 1. While the system works quite well under relatively steady conditions, use of it during transients has revealed important limitations on feedback control of impurity seeding in conventional vertical target plate divertors. In some cases, the system is unable to avoid plasma reattachment to the divertor plate or the formation of a confinement-damaging x-point MARFE. This is due to the small operational window for mitigated heat flux in the parameters of incident plasma heat flux, plasma density, and impurity density as well as the relatively slow response of the impurity gas injection system compared to plasma transients. Given the severe consequences for failure of such a system to operate reliably in a reactor, there is substantial risk that the conventional vertical target plate divertor will not provide an adequately controllable system in reactor-class devices. These considerations motivate the need to develop passively stable, highly compliant divertor configurations and experimental facilities that can test such possible solutions.
Research and development of photovoltaic power system. Characterization and control of surface/interface recombination velocity of crystalline silicon thin films; Taiyoko hatsuden system no kenkyu kaihatsu. Silicon kessho usumaku ni okeru hyomen kaimen saiketsugo sokudo no hyoka to seigyo
Energy Technology Data Exchange (ETDEWEB)
Hasegawa, H. [Hokkaido University, Sapporo (Japan). Faculty of Engineering
This paper reports the result obtained during fiscal 1994 on characterization and control of surface/interface recombination velocity of crystalline silicon thin films. To optimize design and manufacture of solar cells, it is necessary to identify correctly resistance factor (or doping) of bulk of materials, bulk minority carrier life, and recombination velocity on surface, passivation interface and electrode interface. A group in the Hokkaido University has been working since a few years ago on development of non-contact and non-destructive photo-luminescence surface level spectroscopy (PLS{sup 3}). A new non-contact C-V method was also introduced. Using these methods, basic discussions were given on possibility of separate measurements on surface/interface and bulk characteristics of solar cell materials. The PLS{sup 3} method and the non-contact C-V method were used for experimental discussions on evaluation of silicon mono-crystalline and poly-crystalline materials. Discussions were given on separate evaluations by using the DLTS method. 10 figs., 2 tabs.
Green Power Partnership Videos
The Green Power Partnership develops videos on a regular basis that explore a variety of topics including, Green Power partnership, green power purchasing, Renewable energy certificates, among others.
Conformal Ultracapacitor Power Source Technology for the Miniature Kill Vehicle
National Research Council Canada - National Science Library
.... The conformal ultracapacitor power source will be attached to the inside available surface of the individual miniature kill vehicle, The ultracapacitor will be charged through a charging system...
Genton, Marc G.
In this paper, we introduce a surface boxplot as a tool for visualization and exploratory analysis of samples of images. First, we use the notion of volume depth to order the images viewed as surfaces. In particular, we define the median image. We use an exact and fast algorithm for the ranking of the images. This allows us to detect potential outlying images that often contain interesting features not present in most of the images. Second, we build a graphical tool to visualize the surface boxplot and its various characteristics. A graph and histogram of the volume depth values allow us to identify images of interest. The code is available in the supporting information of this paper. We apply our surface boxplot to a sample of brain images and to a sample of climate model outputs.
Busemann, Herbert
This exploration of convex surfaces focuses on extrinsic geometry and applications of the Brunn-Minkowski theory. It also examines intrinsic geometry and the realization of intrinsic metrics. 1958 edition.
Pv-Thermal Solar Power Assembly
Ansley, Jeffrey H.; Botkin, Jonathan D.; Dinwoodie, Thomas L.
A flexible solar power assembly includes a flexible photovoltaic device attached to a flexible thermal solar collector. The solar power assembly can be rolled up for transport and then unrolled for installation on a surface, such as the roof or side wall of a building or other structure, by use of adhesive and/or other types of fasteners.
International Nuclear Information System (INIS)
Silva, S. da; Teixeira, M.V.
The general methods of surface decontamination used in laboratory and others nuclear installations areas, as well as the procedures for handling radioactive materials and surfaces of work are presented. Some methods for decontamination of body external parts are mentioned. The medical supervision and assistance are required for internal or external contamination involving or not lesion in persons. From this medical radiation protection decontamination procedures are determined. (M.C.K.) [pt
Improved control system power unit for large parachutes
Chandler, J. A.; Grubbs, T. M.
Improved control system power unit drives the control surfaces of very large controllable parachutes. The design features subassemblies for determining control surface position and cable loading, and protection of the load sensor against the possibility of damage during manipulation.
Wette, Frederik
In recent years substantial progress has been made in the detection of surface phonons owing to considerable improvements in inelastic rare gas scattering tech niques and electron energy loss spectroscopy. With these methods it has become possible to measure surface vibrations in a wide energy range for all wave vectors in the two-dimensional Brillouin zone and thus to deduce the complete surface phonon dispersion curves. Inelastic atomic beam scattering and electron energy loss spectroscopy have started to play a role in the study of surface phonons similar to the one played by inelastic neutron scattering in the investigation of bulk phonons in the last thirty years. Detailed comparison between experimen tal results and theoretical studies of inelastic surface scattering and of surface phonons has now become feasible. It is therefore possible to test and to improve the details of interaction models which have been worked out theoretically in the last few decades. At this point we felt that a concise, co...
Human Power Empirically Explored
Jansen, A.J.
Harvesting energy from the users' muscular power to convert this into electricity is a relatively unknown way to power consumer products. It nevertheless offers surprising opportunities for product designers; human-powered products function independently from regular power infrastructure, are
Power manager and method for managing power
Burchard, A.T.; Kersten, G.; Molnos, A.M.; Milutinovic, A.; Goossens, K.G.W.; Steffens, E.F.M.
A power manager (106) and method for managing the power supplied to an electronic device is provided. Furthermore, a system wherein the power supplied to an electronic device is managed is provided. The power manager (106) is operative to monitor a hardware monitor (104) during a monitoring time
Oki, Delwyn S.
Surface water in Hawaii is a valued resource as well as a potential threat to human lives and property. The surface-water resources of Hawaii are of significant economic, ecologic, cultural, and aesthetic importance. Streams supply more than 50 percent of the irrigation water in Hawaii, and although streams supply only a few percent of the drinking water statewide, surface water is the main source of drinking water in some places. Streams also are a source of hydroelectric power, provide important riparian and instream habitats for many unique native species, support traditional and customary Hawaiian gathering rights and the practice of taro cultivation, and possess valued aesthetic qualities. Streams affect the physical, chemical, and aesthetic quality of receiving waters, such as estuaries, bays, and nearshore waters, which are critical to the tourism-based economy of the islands. Streams in Hawaii pose a danger because of their flashy nature; a stream's stage, or water level, can rise several feet in less than an hour during periods of intense rainfall. Streams in Hawaii are flashy because rainfall is intense, drainage basins are small, basins and streams are steep, and channel storage is limited. Streamflow generated during periods of heavy rainfall has led to loss of property and human lives in Hawaii. Most Hawaiian streams originate in the mountainous interiors of the islands and terminate at the coast. Streams are significant sculptors of the Hawaiian landscape because of the erosive power of the water they convey. In geologically young areas, such as much of the southern part of the island of Hawaii, well-defined stream channels have not developed because the permeability of the surface rocks generally is so high that rainfall infiltrates before flowing for significant distances on the surface. In geologically older areas that have received significant rainfall, streams and mass wasting have carved out large valleys.
Optimization of process parameters for friction stir processing (FSP ...
Indian Academy of Sciences (India)
Segregation of in situ formed particles at the grain boundaries is a major drawback of in situ composites. In this study, it has been ... The aim of the present study is to improve the homo- geneity of particle distribution in Al–TiC in .... depends on the value of α and hence, affects the particle distribution the same way as α does.
Power theories for improved power quality
Pasko, Marian
Power quality describes a set of parameters of electric power and the load's ability to function properly under specific conditions. It is estimated that problems relating to power quality costs the European industry hundreds of billions of Euros annually. In contrast, financing for the prevention of these problems amount to fragments of these costs. Power Theories for Improved Power Quality addresses this imbalance by presenting and assessing a range of methods and problems related to improving the quality of electric power supply. Focusing particularly on active compensators and the DSP based control algorithms, Power Theories for Improved Power Quality introduces the fundamental problems of electrical power. This introduction is followed by chapters which discuss: •'Power theories' including their historical development and application to practical problems, •operational principles of active compensator's DSP control based algorithms using examples and results from laboratory research, and •t...
Schuman, Patricia Glass
Discusses the concept of power in the context of women and the library profession, citing views of power by Max Weber, John Kenneth Galbraith, Letty Cottin Pogrebin, and Rosabeth Moss Kantor. Male power and female submission, defining power, organizing for power, and sharing power are highlighted. A 12-item bibliography is included. (EJS)
Progress in surface and membrane science
Cadenhead, D A
Progress in Surface and Membrane Science, Volume 11 covers the advances in the study of surface and membrane science. The book discusses the quantum theory of surface phenomena; some fundamental aspects of electrocrystallization; and exoelectric emission. The text also describes the surface of titanium dioxide; and the prospects for atomic resolution electron microscopy in membranology. Chemists, physicists, and people involved in the electrochemical power laboratory will find the book useful.
Shultz, Mary Jane
Ice is a fundamental solid with important environmental, biological, geological, and extraterrestrial impact. The stable form of ice at atmospheric pressure is hexagonal ice, Ih. Despite its prevalence, Ih remains an enigmatic solid, in part due to challenges in preparing samples for fundamental studies. Surfaces of ice present even greater challenges. Recently developed methods for preparation of large single-crystal samples make it possible to reproducibly prepare any chosen face to address numerous fundamental questions. This review describes preparation methods along with results that firmly establish the connection between the macroscopic structure (observed in snowflakes, microcrystallites, or etch pits) and the molecular-level configuration (detected with X-ray or electron scattering techniques). Selected results of probing interactions at the ice surface, including growth from the melt, surface vibrations, and characterization of the quasi-liquid layer, are discussed.
Dynamic power flow controllers
Energy Technology Data Exchange (ETDEWEB)
Divan, Deepakraj M.; Prasai, Anish
Dynamic power flow controllers are provided. A dynamic power flow controller may comprise a transformer and a power converter. The power converter is subject to low voltage stresses and not floated at line voltage. In addition, the power converter is rated at a fraction of the total power controlled. A dynamic power flow controller controls both the real and the reactive power flow between two AC sources having the same frequency. A dynamic power flow controller inserts a voltage with controllable magnitude and phase between two AC sources; thereby effecting control of active and reactive power flows between two AC sources.
Exploration mission enhancements possible with power beaming
International Nuclear Information System (INIS)
Bamberger, J.A.; Coomes, E.P.; Segna, D.R.
A key factor in the exploration and development of the space frontier is the availability of energy where and when it is needed. Currently all space satellites and platforms include self-contained power systems that supply the energy necessary to accomplish mission objectives. An alternative approach is to couple advanced high power systems with energy beam transmitters and energy receivers to form an infrastructure of a space power utility where a central power system provides power to multiple users. Major space activities, such as low Earth orbit space commercialization and the colonization of the Moon or Mars, would benefit significantly from a central power generation and transmission system. This paper describes the power-beaming concept and system components as applied to space power generation and distribution in support of the Space Exploration Initiative. Beam-power scenarios are discussed including commonality of systems and hardware with cargo transport vehicles, power beaming from orbit to stationary and mobile users on the Lunar and Mars surfaces, and other surface applications
Nuclear power plants in electric power system
International Nuclear Information System (INIS)
Leicman, J.; Vokurka, F.
The paper analyzes the demands placed by the power system on operating qualities of nuclear power plants with regard to the prospective tasks of nuclear power in the Czechoslovak power system. The characteristics of the operation of Czechoslovak nuclear plants are given taking into account the frequency and voltage deviations of the network, operating and control properties of nuclear power plants with WWER-440 and WWER-1000 reactors considering the technical conditions of operation, the required operating schedule of a nuclear power plant unit. For comparison, the demands are summed up of foreign power systems as are the control properties of foreign nuclear power units in regulating output, regulating delivered electric power and in emergency states of the system. Recommendations for further research and development are drawn from the data. (author)
Lunar solar-power system: Commerical power
Criswell, David R.
The proposed Lunar Solar-Power (LSP) System collects solar power on the moon. The power is converted to beams of microwaves and transmitted to fields of microwave receivers (rectennas) on Earth that provide electric power to local and regional power grids. LSP can provide abundant and low cost energy to Earth to sustain several centuries of economic development on Earth and in space. The LSP power is independent of the biosphere (global warming, weather, and climate changes), independent of reserves of terrestrial non-renewable and renewable power, and is low in total costs compared to other large scale power systems. Efficient utilization of the moon as a platform for solar collectors/power transmitters and as a source of building materials is key to the development and emplacement of the LSP System. LSP development costs can be significantly reduced by the establishment of a manned lunar base.
International Nuclear Information System (INIS)
Glass, Lisa; Ferrarese, Laura; Cote, Patrick; Blakeslee, John P.; Chen, Chin-Wei; Jordan, Andres; Infante, Leopoldo; Peng, Eric; Mei, Simona; Tonry, John L.; West, Michael J.
Although early observations with the Hubble Space Telescope (HST) pointed to a sharp dichotomy among early-type galaxies in terms of the logarithmic slope γ' of their central surface brightness profiles, several studies in the past few years have called this finding into question. In particular, recent imaging surveys of 143 early-type galaxies belonging to the Virgo and Fornax Clusters using the Advanced Camera for Surveys (ACS) on board HST have not found a dichotomy in γ', but instead a systematic progression from central luminosity deficit to excess relative to the inward extrapolation of the best-fitting global Sersic model. Given that earlier studies also found that the dichotomy persisted when analyzing the deprojected density profile slopes, we investigate the distribution of the three-dimensional luminosity density profiles of the ACS Virgo and Fornax Cluster Survey galaxies. Having fitted the surface brightness profiles with modified Sersic models, we then deproject the galaxies using an Abel integral and measure the inner slopes γ 3D of the resulting luminosity density profiles at various fractions of the effective radius R e . We find no evidence of a dichotomy, but rather, a continuous variation in the central luminosity profiles as a function of galaxy magnitude. We introduce a parameter, Δ 3D , that measures the central deviation of the deprojected luminosity profiles from the global Sersic fit, showing that this parameter varies smoothly and systematically along the luminosity function.
DEFF Research Database (Denmark)
Lutz, Peter
such as schedules, machines, and aging bodies. To this end, the article also experiments with 'surfacing' as an ethnographic heuristic for figuring these different 'spatial-timings'. The article concludes that surfacing matters not only in senior home care but also in the field-desks of ethnographic analysis....
DEFF Research Database (Denmark)
Gruschka, Nils; Jensen, Meiko
The new paradigm of cloud computing poses severe security risks to its adopters. In order to cope with these risks, appropriate taxonomies and classification criteria for attacks on cloud computing are required. In this work-in-progress paper we present one such taxonomy based on the notion...... of attack surfaces of the cloud computing scenario participants....
A Maximum Power Tracker for Improved Thermophotovoltaic Power Generation, Phase I
National Aeronautics and Space Administration — Radioisotope Power Systems (RPS) are critical for future flagship exploration missions in space and on planetary surfaces. Small improvements in the RPS performance,...
International Nuclear Information System (INIS)
Kirkaldy, J.S.
The report deals broadly with tritium-surface interactions as they relate to a fusion power reactor enterprise, viz., the vacuum chamber, first wall, peripherals, pumping, fuel recycling, isotope separation, repair and maintenance, decontamination and safety. The main emphasis is on plasma-surface interactions and the selection of materials for fusion chamber duty. A comprehensive review of the international (particularly U.S.) research and development is presented based upon a literature review (about 1 000 reports and papers) and upon visits to key laboratories, Sandia, Albuquerque, Sandia, Livermore and EGβG Idaho. An inventory of Canadian expertise and facilities for RβD on tritium-surface interactions is also presented. A number of proposals are made for the direction of an optimal Canadian RβD program, emphasizing the importance of building on strength in both the technological and fundamental areas. A compendium of specific projects and project areas is presented dealing primarily with plasma-wall interactions and permeation, anti-permeation materials and surfaces and health, safety and environmental considerations. Potential areas of industrial spinoff are identified
International Nuclear Information System (INIS)
Freiwald, J.G.; Freiwald, D.A.
The objective of this work is a laboratory demonstration that red-lead primer and two-part epoxy paints can be stripped from concrete and metal surfaces using surface cleaning systems based on pulsed-repetition CO 2 lasers. The three goals are to: (1) demonstrate coatings removal, including surface pore cleaning; (2) demonstrate that there is negligible release of ablated contaminants to the environment; and (3) demonstrate that the process will generate negligible amounts of additional waste compared to competing technologies. Phase 1 involved site visits to RMI and Fernald to assess the cleaning issues for buildings and parts. In addition, Phase 1 included detailed designs of a more powerful system for industrial cleaning rates, including laser, articulating optics, ablated-material capture suction nozzle attached to a horizontal raster scanner for floor cleaning, and filtration system. Some concept development is also being done for using robots, and for parts cleaning. In Phase 2 a transportable 6 kW system will be built and tested, with a horizontal surface scanner for cleaning paint from floors. The laboratory tests will again be instrumented. Some concept development will continue for using robots, and for parts cleaning. This report describes Phase 1 results
Swept-source optical coherence tomography powered by a 1.3-μm vertical cavity surface emitting laser enables 2.3-mm-deep brain imaging in mice in vivo
Choi, Woo June; Wang, Ruikang K.
We report noninvasive, in vivo optical imaging deep within a mouse brain by swept-source optical coherence tomography (SS-OCT), enabled by a 1.3-μm vertical cavity surface emitting laser (VCSEL). VCSEL SS-OCT offers a constant signal sensitivity of 105 dB throughout an entire depth of 4.25 mm in air, ensuring an extended usable imaging depth range of more than 2 mm in turbid biological tissue. Using this approach, we show deep brain imaging in mice with an open-skull cranial window preparation, revealing intact mouse brain anatomy from the superficial cerebral cortex to the deep hippocampus. VCSEL SS-OCT would be applicable to small animal studies for the investigation of deep tissue compartments in living brains where diseases such as dementia and tumor can take their toll.
Assessinent of streptomycesgriseo viridis (mycostop as a biocontrol agent for fusarium oxysporum f. sp. dianthiin two cultivars of standard carnation under commercial conditions Evaluación de Streptomyces griseoviridis (MYCOSTOP en el control de Fusarium oxysporum f.sp. dianthi, en dos variedades de clavel estándar bajo condiciones comerciales
Directory of Open Access Journals (Sweden)
Ortega Luis Miguel
Full Text Available The research was carried out in a commercial farm, located in Madrid, Cundinamarca. The purpose of the study was to established the rate and irequency of application of Streptomyces griseoviridis (Mycostop in the control of vascular wilt of carnation caused by Fusarium oxysporum f.sp. dianthi. Two experiments were conducted to compare three rates of application (0,025;0,05 and 0,01 g/m2 and
three intervals of application (1,2 and 4 weeks of
Mycostop, in two standard carnation varieties. Disease
progress data were analized by comparing their godness of fit to Gompertz and Monomolecular epidemiological models. By using the simpler linear regression model, the rate of inlection (k and the coefficient of determination (Al were calculated.
Inlection rates were subjected to analysis of variance.
The results showed no satislactory control of the disease. Rates and frecuencies of applícation of Streptomyces griseoviridis (Mycostop did not show appreciable differences. Epidemiologically, "k" values were highly homogeneous among the different Mycostop treatments. Streptomyces
griseoviridisis highly dependent upon culture media
pH, and it grows only at a pH 016,4 or higher, with an optimal growth at a pH 7,0. No relation was detected between growth of the biocontrol organism and levels of electrical conductivity.La investigación se realizó en un cultivo comercial de clavel localizado en el municipio de Madrid (Cundinamarca, con el objetivo de determinar la dosis y la frecuencia de aplicación de Streptomyces griseoviridis (Mycostop en el control del
marchitamiento vascular ocasionado por Fusarium oxysporom lsp. dianthi. En el campo, se realizaron dos experimentos simultáneos, para probar diferentes dosis (0,025; 0,05 y 0,1 g/m2 y frecuencias (1, 2 y 4 semanas de aplicación de
Streptomyces griseoviridis Mycostop en dos variedades de clavel estándar. El análisis estadístico consistió en utilizar algunos
Pneumatic tire-based piezoelectric power generation
Makki, Noaman; Pop-Iliev, Remon
Plug-in Hybrid Electric Vehicles (PHEVs) and Extended Range Electric Vehicles (EREVs) currently mainly rely on Internal Combustion Engines (ICE) utilizing conventional fuels to recharge batteries in order to extend their range. Even though Piezo-based power generation devices have surfaced in recent years harvesting vibration energy, their output has only been sufficient to power up sensors and other such smaller devices. The permanent need for a cleaner power generation technique still remains. This paper investigates the possibility of using piezoceramics for power generation within the vehicle's wheel assembly by exploiting the rotational motion of the wheel and the continuously variable contact point between the pneumatic tire and the road.
International Nuclear Information System (INIS)
Haas, Elisabeth de
Full text: In 1997 and as a result of political developments in the Dutch government's energy policy, the Nuclear Power Plant (NPP) Dodewaard was forced to stop producing electricity for the national grid. As a consequence, plans for the decommissioning of the NPP were developed. For the Netherlands this is a first-of-a-kind project: so far no nuclear installation has been actually dismantled in this country. GKN, the operator of NPP Dodewaard, started a vast decommissioning project. Four years elapsed before a concept was ready for the licence required to carry out the plans. The scope of activities is as follows. Once all spent fuel has been removed from the site the installation will be brought into a state of so-called Safe Enclosure, which will ensure that all radioactivity remaining inside components and buildings, can be kept safely locked in for a period of 40 years. At the end of this 40 year waiting period, when radiation levels will have dropped considerably in a natural way, the NPP will be dismantled and the grounds on which the complex was built can return to be the green meadow-land they once were. The process of convincing the Dutch government and obtaining approval for these plans took a lot of time and effort from GKN's side. Now - almost five years later - we have reached the stage that the text of the concept licence has been made public to the Dutch citizens who, within a defined period of time, may submit any objections they have, prior to the licence becoming final. In the Netherlands a majority of the people are not exactly enthusiastic about nuclear. Therefore, PR matters related to the Dodewaard NPP are mostly been handled low-key and in a reactive way rather than pro-actively. But with respect to the plans for the future of the Dodewaard plant, operator GKN felt a distinct obligation to inform in a timely and active manner both our government as well as the man in the street. With that objective in mind, we decided to develop an in
Power electronics for low power arcjets
Hamley, John A.; Hill, Gerald M.
In anticipation of the needs of future light-weight low-power spacecraft, arcjet power electronics in the 100- to 400-W operating range were developed. Power topologies similar to those in the higher 2-kW and 5- to 30-kW power range were implemented, including a four-transistor bridge-switching circuit, current-mode pulse-width modulated control, and an output current averaging inductor with an integral pulse generation winding. Reduction of switching transients was accomplished using a low inductance power distribution network, and no passive snubber circuits were necessary for power switch protection. Phase shift control of the power bridge was accomplished using an improved pulse width modulation to phase shift converter circuit. These features, along with conservative magnetics designs, allowed power conversion efficiencies of greater than 92.5 percent to be achieved into resistive loads over the entire operating range of the converter.
International Nuclear Information System (INIS)
Ishii, Yoshihiko; Arita, Setsuo; Miyamoto, Yoshiyuki; Fukazawa, Yukihisa; Ishii, Kazuhiko
The present invention provides a reactor power control device capable of enhancing an operation efficiency while keeping high reliability and safety in a BWR type nuclear power plant. Namely, the device of the present invention comprises (1) a means for inputting a set value of a generator power and a set value of a reactor power, (2) a means for controlling the reactor power to either smaller one of the reactor power corresponding to the set value of the generator power and the set value of the reactor power. With such procedures, even if the nuclear power plant is set so as to operate it to make the reactor power 100%, when the generator power reaches the upper limit, the reactor power is controlled with a preference given to the upper limit value of the generator power. Accordingly, safety and reliability are not deteriorated. The operation efficiency of the plant can be improved. (I.S.)
Sound radiation from finite surfaces
DEFF Research Database (Denmark)
Brunskog, Jonas
A method to account for the effect of finite size in acoustic power radiation problem of planar surfaces using spatial windowing is developed. Cremer and Heckl presents a very useful formula for the power radiating from a structure using the spatially Fourier transformed velocity, which combined...... with spatially windowing of a plane waves can be used to take into account the finite size. In the present paper, this is developed by means of a radiation impedance for finite surfaces, that is used instead of the radiation impedance for infinite surfaces. In this way, the spatial windowing is included...... in the radiation formula directly, and no pre-windowing is needed. Examples are given for the radiation efficiency, and the results are compared with results found in the literature....
Switching power converters medium and high power
Neacsu, Dorin O
An examination of all of the multidisciplinary aspects of medium- and high-power converter systems, including basic power electronics, digital control and hardware, sensors, analog preprocessing of signals, protection devices and fault management, and pulse-width-modulation (PWM) algorithms, Switching Power Converters: Medium and High Power, Second Edition discusses the actual use of industrial technology and its related subassemblies and components, covering facets of implementation otherwise overlooked by theoretical textbooks. The updated Second Edition contains many new figures, as well as
Energy Technology Data Exchange (ETDEWEB)
Brocato, Robert W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
This report describes an unpowered radio receiver capable of detecting and responding to weak signals transmit ted from comparatively long distances . This radio receiver offers key advantages over a short range zero - power radio receiver previously described in SAND2004 - 4610, A Zero - Power Radio Receiver . The device described here can be fabricated as an integrated circuit for use in portable wireless devices, as a wake - up circuit, or a s a stand - alone receiver operating in conjunction with identification decoders or other electroni cs. It builds on key sub - components developed at Sandia National Laboratories over many years. It uses surface acoustic wave (SAW) filter technology. It uses custom component design to enable the efficient use of small aperture antennas. This device uses a key component, the pyroelectric demodulator , covered by Sandia owned U.S. Patent 7397301, Pyroelectric Demodulating Detector [1] . This device is also described in Sandia owned U.S. Patent 97266446, Zero Power Receiver [2].
The airborne power supply study considers the conversion of 400 cycle aircraft power to regulated DC voltages. Topics include the review of present...power conversion techniques, monolithic IC and hybrid series voltage regulators, power supply problem areas, trade-off considerations and power system
Kranichfeld, Marion L.
Men's power is emphasized in the family power literature on marital decision making. Little attention has been paid to women's power, accrued through their deeper embeddedness in intrafamilial roles. Micro-level analysis of family power demonstrates that women's positions in the family power structure rest not on the horizontal marital tie but…
Good Health: The Power of Power
Corbin, Charles B.; Janz, Kathleen F.; Baptista, Fátima
Power has long been considered to be a skill-related fitness component. However, based on recent evidence, a strong case can be made for the classification of power as a health-related fitness component. Additionally, the evidence indicates that performing physical activities that build power is associated with the healthy development of bones…
Analysis of superconducting microstrip resonator at various microwave power levels
Energy Technology Data Exchange (ETDEWEB)
Srivastava, G.P.; Jacob, M.V.; Jayakumar, M.; Bhatnagar, P.K. [Department of Electronic Science, University of Delhi, South Campus, Benito Juarez Road, New Delhi 110021 (India); Kataria, N.D. [National Physical Laboratory, K. S. Krishnan Road, New Delhi 110 012 (India)
The real and imaginary parts of the surface impedance of YBCO superconductors have been studied at different microwave power levels. Using the relations for the critical current density and the grain boundary resistance, a relation for calculating the power dependence of the surface resistance has been obtained. Also, a relation to find the resonant frequency of a superconducting microstrip resonator at various input power levels has been derived. Measurements have been carried out on various microstrip resonators to study the variation of surface resistance and resonant frequency at different rf power levels. The experimental results are in good agreement with theoretical results. {copyright} {ital 1997 American Institute of Physics.}
Study and characterization of noble metal deposits on similar rusty surfaces to those of the reactor U-1 type BWR of nuclear power station of Laguna Verde; Estudio y caracterizacion de depositos de metales nobles sobre superficies oxidadas similares a las del reactor de la Central de Laguna Verde (CNLV) U1 del tipo BWR
Energy Technology Data Exchange (ETDEWEB)
Flores S, V. H.
In the present investigation work, were determined the parameters to simulate the conditions of internal oxidation reactor circulation pipes of the nuclear power plant of Laguna Verde in Veracruz. We used 304l stainless steel cylinders with two faces prepared with abrasive paper of No. 600, with the finality to obtain similar surface to the internal circulation piping nuclear reactor. Oxides was formed within an autoclave (Autoclave MEX-02 unit B), which is a device that simulates the working conditions of the nuclear reactor, but without radiation generated by the fission reaction within the reactor. The oxidation conditions were a temperature of 280 C and pressure of 8 MPa, similar conditions to the reactor operating in nuclear power plant of Laguna Verde in Veracruz, Mexico (BWR conditions), with an average conductivity of 4.58 ms / cm and 2352 ppb oxygen to simulate normal water chemistry NWC. Were obtained deposits of noble metal oxides formed on 304l stainless steel samples, in a 250 ml autoclave at a temperature range of 180 to 200 C. The elements that were used to deposit platinum-rhodium (Pt-Rh) with aqueous Na{sub 2}Pt (OH){sub 6} and Na{sub 3}Rh (NO{sub 2}){sub 6}, Silver (Ag) with an aqueous solution of AgNO{sub 3}, zirconium (Zr) with aqueous Zr O (NO{sub 3}) and ZrO{sub 2}, and zinc (Zn) in aqueous solution of Zn (NO{sub 3}){sub 2} under conditions of normal water chemistry. Also there was the oxidation of 304l stainless steel specimens in normal water chemistry with a solution of Zinc (Zn) (NWC + Zn). Oxidation of the specimens in water chemistry with a solution of zinc (Zn + NWC) was prepared in two ways: within the MEX-02 autoclave unit A in a solution of zinc and a flask at constant temperature in zinc solution. The oxides formed and deposits were characterized by scanning electron microscopy, energy dispersive X-ray analysis, elemental field analysis and X-ray diffraction. By other hand was evaluated the electrochemical behavior of the oxides
On the nature of surface roughness with application to contact mechanics, sealing, rubber friction and adhesion
International Nuclear Information System (INIS)
Persson, B N J; Albohr, O; Tartaglino, U; Volokitin, A I; Tosatti, E
Surface roughness has a huge impact on many important phenomena. The most important property of rough surfaces is the surface roughness power spectrum C(q). We present surface roughness power spectra of many surfaces of practical importance, obtained from the surface height profile measured using optical methods and the atomic force microscope. We show how the power spectrum determines the contact area between two solids. We also present applications to sealing, rubber friction and adhesion for rough surfaces, where the power spectrum enters as an important input. (topical review)
Power Burst Facility: power oscillation problem
International Nuclear Information System (INIS)
Lussie, W.G.; Wadkins, R.P.; Wells, R.A.
In late 1973 PBF achieved a power level of 15 MW. During this period of operation fluctuations in reactor power were observed. Many possible causes of these fluctuations were considered and a number of nuclear and non-nuclear tests were conducted. Initial instrumentation installed in the core showed coolant outlet temperature variations of 10 0 F for several fuel cannisters and approximately 10 percent power variations at 15 MW. Power spectral density analysis showed a predominant frequency of 0.05 to 0.06 HZ. The testing program to determine the cause of the power oscillations is described
Wind power in modern power systems
DEFF Research Database (Denmark)
Chen, Zhe
In recent years, wind power is experiencing a rapid growth, and large-scale wind turbines/wind farms have been developed and connected to power systems. However, the traditional power system generation units are centralized located synchronous generators with different characteristics compared...... with wind turbines. This paper presents an overview of the issues about integrating large-scale wind power plants into modern power systems. Firstly, grid codes are introduced. Then, the main technical problems and challenges are presented. Finally, some possible technical solutions are discussed....
Wind Power - A Power Source Enabled by Power Electronics
DEFF Research Database (Denmark)
Blaabjerg, Frede; Chen, Zhe
The global electrical energy consumption is still rising and there is a steady demand to increase the power capacity. The production, distribution and the use of the energy should be as technological efficient as possible and incentives to save energy at the end-user should be set up. The deregul......The global electrical energy consumption is still rising and there is a steady demand to increase the power capacity. The production, distribution and the use of the energy should be as technological efficient as possible and incentives to save energy at the end-user should be set up....... The deregulation of energy has lowered the investment in bigger power plants, which means the need for new electrical power sources may be very high in the near future. Two major technologies will play important roles to solve the future problems. One is to change the electrical power production sources from...... the conventional, fossil (and short term) based energy sources to renewable energy sources. The other is to use high efficient power electronics in power systems, power production and end-user application. This paper discuss the most emerging renewable energy source, wind energy, which by means of power...
Kansas Data Access and Support Center — The Kansas Power Plants database depicts, as point features, the locations of the various types of power plant locations in Kansas. The locations of the power plants...
EPA Green Power Partners can access tools and resources to help promote their green power commitments. Partners use these tools to communicate the benefits of their green power use to their customers, stakeholders, and the general public.
Energy Technology Data Exchange (ETDEWEB)
Nirm V. Nirmalan
Gas turbines are the choice technology for high-performance power generation and are employed in both simple and combined cycle configurations around the world. The Smart Power Turbine (SPT) program has developed new technologies that are needed to further extend the performance and economic attractiveness of gas turbines for power generation. Today's power generation gas turbines control firing temperatures indirectly, by measuring the exhaust gas temperature and then mathematically calculating the peak combustor temperatures. But temperatures in the turbine hot gas path vary a great deal, making it difficult to control firing temperatures precisely enough to achieve optimal performance. Similarly, there is no current way to assess deterioration of turbine hot-gas-path components without shutting down the turbine. Consequently, maintenance and component replacements are often scheduled according to conservative design practices based on historical fleet-averaged data. Since fuel heating values vary with the prevalent natural gas fuel, the inability to measure heating value directly, with sufficient accuracy and timeliness, can lead to maintenance and operational decisions that are less than optimal. GE Global Research Center, under this Smart Power Turbine program, has developed a suite of novel sensors that would measure combustor flame temperature, online fuel lower heating value (LHV), and hot-gas-path component life directly. The feasibility of using the ratio of the integrated intensities of portions of the OH emission band to determine the specific average temperature of a premixed methane or natural-gas-fueled combustion flame was demonstrated. The temperature determined is the temperature of the plasma included in the field of view of the sensor. Two sensor types were investigated: the first used a low-resolution fiber optic spectrometer; the second was a SiC dual photodiode chip. Both methods worked. Sensitivity to flame temperature changes was
Autonomous power networks based power system
International Nuclear Information System (INIS)
Jokic, A.; Van den Bosch, P.P.J.
This paper presented the concept of autonomous networks to cope with this increased complexity in power systems while enhancing market-based operation. The operation of future power systems will be more challenging and demanding than present systems because of increased uncertainties, less inertia in the system, replacement of centralized coordinating activities by decentralized parties and the reliance on dynamic markets for both power balancing and system reliability. An autonomous network includes the aggregation of networked producers and consumers in a relatively small area with respect to the overall system. The operation of an autonomous network is coordinated and controlled with one central unit acting as an interface between internal producers/consumers and the rest of the power system. In this study, the power balance problem and system reliability through provision of ancillary services was formulated as an optimization problem for the overall autonomous networks based power system. This paper described the simulation of an optimal autonomous network dispatching in day ahead markets, based on predicted spot prices for real power, and two ancillary services. It was concluded that large changes occur in a power systems structure and operation, most of them adding to the uncertainty and complexity of the system. The introduced concept of an autonomous power network-based power system was shown to be a realistic and consistent approach to formulate and operate a market-based dispatch of both power and ancillary services. 9 refs., 4 figs
International Nuclear Information System (INIS)
Data concerning the existing nuclear power plants in the world are presented. The data was retrieved from the SIEN (Nuclear and Energetic Information System) data bank. The information are organized in table forms as follows: nuclear plants, its status and type; installed nuclear power plants by country; nuclear power plants under construction by country; planned nuclear power plants by country; cancelled nuclear power plants by country; shut-down nuclear power plants by country. (E.G.) [pt
Federal Laboratory Consortium — TVA's Power Service Shops provides expert repair and maintenance of power system components and large industrial equipment. With world-class maintenance facilities...
National Aeronautics and Space Administration — The AES Modular Power Systems (AMPS) project will demonstrate and infuse modular power electronics, batteries, fuel cells, and autonomous control for exploration...
Monoclonal antibodies against rat leukocyte surface antigens
van den Berg, T. K.; Puklavec, M. J.; Barclay, A. N.; Dijkstra, C. D.
Monoclonal antibodies have proven to be powerful tools for studying the properties of leukocyte surface antigens and the cells that express them. In the past decades many monoclonal antibodies (mAb) for identifying the different rat leukocyte surface antigens have been described. A list of mAb is
Wind power - a power source now enabled by power electronics
DEFF Research Database (Denmark)
Blaabjerg, Frede; Iov, Florin
energy at the end-user should be set up. Deregulation of energy has lowered the investment in larger power plants, which means the need for new electrical power sources may be increased in the near future. Two major technologies will play important roles to solve the future problems. One is to change...
FY 1979 Annual report on Sunshine Project results. Fabrication designs for a solar thermal power pilot plant with curved-surface type light-collecting system (Part 2); 1979 nendo taiyonetsu hatsuden (kyokumen shuko hoshiki) seika hokokusho. 2. Pilot plant no seisaku sekkei
Energy Technology Data Exchange (ETDEWEB)
Part 1 of this report (JN0040511) describes basic and fabrication design specifications for operation and control of a solar thermal power pilot plant with curved-surface type light-collecting system, centered by computer for the plant control. Part 2 follows Part 1, which describes basic fabrication design specifications (Chapter I), system design specifications (Chapter II), hardware specifications (Chapter III) and attachments (Chapter IV), to contain the other attachments: daily processing specifications, computer-aided processing function specifications, operator request function specifications, summary data collection function specifications, basic structures of the software systems, basic specifications for computer inputting/outputting, failure display panel drawings, COD/channel base dimension drawings, console inputting/outputting dimension drawings, T/W disc dimension drawings, viewer external dimension drawings, cassette MT structure dimension drawings, operator console panel drawings, power source panel dimension drawings, program specifications GFC, 4 subroutine specifications GFC (R sub), table list, table structure drawings, and analysis of system characteristics (light- and heat-collection system simulation). (NEDO)
International Nuclear Information System (INIS)
Imbo, T.D.; March-Russel, J.
We investigate the allowed spectrum of statistics for n identical spinless particles on an arbitrary closed two-manifold M, by using a powerful topological approach to the study of quantum kinematics. On a surface of genus g≥1 statistics other than Bose or Fermi can only be obtained by utilizing multi-component state vectors transforming as an irreducible unitary representation of the fundamental group of the n-particle configuration space. These multi-component (or nonscalar) quantizations allow the possibility of fractional statistics, as well as other exotic, nonfractional statistics some of whose properties we discuss. On an orientable surface of genus g≥0 only anyons with rational statistical parameter θ/π=p/q are allowed, and their number is restricted to be sq-g+1 (selement ofZ). For nonorientable surfaces only θ=0, π are allowed. Finally, we briefly comment on systems of spinning particles and make a comparison with the results for solitons in the O(3)-invariant nonlinear sigma model with space manifold M. (orig.)
Amphoteric surface active agents
Directory of Open Access Journals (Sweden)
Eissa, A.M. F.
Full Text Available 2-[trimethyl ammonium, triethyl ammonium, pyridinium and 2-amino pyridinium] alkanoates, four series of surface active agents containing carbon chain C12, C14, C16 and C18carbon atoms, were prepared. Their structures were characterized by microanalysis, infrared (IR and nuclear magnetic resonance (NMR. Surface and interfacial tension, Krafft point, wetting time, emulsification power, foaming height and critical micelle concentration (cmc were determined and a comparative study was made between their chemical structure and surface active properties. Antimicrobial activity of these surfactants was also determined.
Se prepararon cuatro series de agentes tensioactivos del tipo 2-[trimetil amonio, trietil amonio, piridinio y 2-amino piridinio] alcanoatos, que contienen cadenas carbonadas con C12, C14, C16 y C18 átomos de carbono.
Se determinaron la tensión superficial e interfacial, el punto de Krafft, el tiempo humectante, el poder de emulsionamiento, la altura espumante y la concentración critica de miscela (cmc y se hizo un estudio comparativo entre la estructura química y sus propiedades tensioactivas. Se determinó también la actividad antimicrobiana de estos tensioactivos. Estas estructuras se caracterizaron por microanálisis, infrarrojo (IR y resonancia magnética nuclear (RMN.
Thin film surface reconstruction analysis
International Nuclear Information System (INIS)
Imperatori, P.
The study of the atomic structure of surfaces and interfaces is a fundamental step in the knowledge and the development of new materials. Among the several surface-sensitive techniques employed to characterise the atomic arrangements, grazing incidence x-ray diffraction (GIXD) is one of the most powerful. With a simple data treatment, based on the kinematical theory, and using the classical methods of x-ray bulk structure determination, it gives the atomic positions of atoms at a surface or an interface and the atomic displacements of subsurface layers for a complete determination of the structure. In this paper the main features of the technique will be briefly reviewed and selected of application to semiconductor and metal surfaces will be discussed
Thin film surface reconstruction analysis
Energy Technology Data Exchange (ETDEWEB)
Imperatori, P. [CNR, Monterotondo Stazione, Rome (Italy). Istituto di Chimica dei materiali
The study of the atomic structure of surfaces and interfaces is a fundamental step in the knowledge and the development of new materials. Among the several surface-sensitive techniques employed to characterise the atomic arrangements, grazing incidence x-ray diffraction (GIXD) is one of the most powerful. With a simple data treatment, based on the kinematical theory, and using the classical methods of x-ray bulk structure determination, it gives the atomic positions of atoms at a surface or an interface and the atomic displacements of subsurface layers for a complete determination of the structure. In this paper the main features of the technique will be briefly reviewed and selected of application to semiconductor and metal surfaces will be discussed.
The spectrum of hyperbolic surfaces
Bergeron, Nicolas
This text is an introduction to the spectral theory of the Laplacian on compact or finite area hyperbolic surfaces. For some of these surfaces, called "arithmetic hyperbolic surfaces", the eigenfunctions are of arithmetic nature, and one may use analytic tools as well as powerful methods in number theory to study them. After an introduction to the hyperbolic geometry of surfaces, with a special emphasis on those of arithmetic type, and then an introduction to spectral analytic methods on the Laplace operator on these surfaces, the author develops the analogy between geometry (closed geodesics) and arithmetic (prime numbers) in proving the Selberg trace formula. Along with important number theoretic applications, the author exhibits applications of these tools to the spectral statistics of the Laplacian and the quantum unique ergodicity property. The latter refers to the arithmetic quantum unique ergodicity theorem, recently proved by Elon Lindenstrauss. The fruit of several graduate level courses at Orsay...
Inglis, David Rittenhouse
The government promotes and heavily subsidizes research in nuclear power plants. Federal development of wind power is slow in comparison even though much research with large wind-electric machines has already been conducted. Unless wind power programs are accelerated it will not become a major energy alternative to nuclear power. (MR)
International Nuclear Information System (INIS)
The Canadian Nuclear Association believes that the CANDU nuclear power generation system can play a major role in achieving energy self-sufficiency in Canada. The benefits of nuclear power, factors affecting projections of electric power demand, risks and benefits relative to other conventional and non-conventional energy sources, power economics, and uranium supply are discussed from a Canadian perspective. (LL)
The electric power engineering handbook power systems
Power Systems, Third Edition (part of the five-volume set, The Electric Power Engineering Handbook) covers all aspects of power system protection, dynamics, stability, operation, and control. Under the editorial guidance of L.L. Grigsby, a respected and accomplished authority in power engineering, and section editors Andrew Hanson, Pritindra Chowdhuri, Gerry Sheble, and Mark Nelms, this carefully crafted reference includes substantial new and revised contributions from worldwide leaders in the field. This content provides convenient access to overviews and detailed information on a diverse arr
PV/thermal solar power assembly
Ansley, Jeffrey H.; Botkin, Jonathan D.; Dinwoodie, Thomas L.
A flexible solar power assembly (2) includes a flexible photovoltaic device (16) attached to a flexible thermal solar collector (4). The solar power assembly can be rolled up for transport and then unrolled for installation on a surface, such as the roof (20, 25) or side wall of a building or other structure, by use of adhesive and/or other types of fasteners (23).
Atmosphere: Power, Critique, Politics
DEFF Research Database (Denmark)
Albertsen, Niels
This paper hans three interrelated parts. First, atmosphere is approached through the concept of power. Atmospheres 'grip' us directly or mediate power indirectly by manipulating moods and evoking emotions. How does atmosphere relate to different conceptions of power? Second, atmospheric powers may...... be critiqued. Which conception of critique can be involved? Third, critiquing atmospheric powers can generate political conflict. How does atmospheric disputes relate to conceptions of politics and the political?...
Ye, Junpei; Zhu, Cheng; Zhang, Panyue; Zhang, Qian; Nabi, Mohammad; Wang, Xuan
This review focuses on the research literature published in 2016 relating to power production waste that results from fossil fuel and nuclear power plants. It elaborates the characterization, reuse and disposal of power production wastes. The wastes from fossil fuel power plants have been divided into fly ash, flue gas desulfurization gypsum and waste catalyst. The environmental issues, associated with nuclear power plants and waste production are also reviewed.
Surynková, Petra
My diploma thesis Surfaces of Building Practice deals with the basic properties of surfaces, their mathematical description, categorization, and application in technical practice. Each studied surface is defined and its process of construction and parametrical description is listed. The thesis studies selected types of surfaces in details - these surfaces include surfaces of revolution, ruled surfaces, screw surfaces, and translational surfaces. An application of each studied surfaces is show...
Surface decontamination by cavitation erosion
International Nuclear Information System (INIS)
Verry, P.; Lecoffre, Y.
The aim of the study is to show the interest of using erosion by cavitation to remove a thin layer of matter from an irradiated surface during nuclear power plant dismantling. Several cavitation devices are tested on different surfaces to erode: aluminum, stainless steel, plexiglas, paints... The process is efficient enough to measure mass loss on materials as hard as stainless steels for a pressure of only 60 bars. Qualification tests using a nozzle feed under a 300 to 600 bar pressure are envisaged
Fabrication of Al5083 surface composites reinforced by CNTs and cerium oxide nano particles via friction stir processing
Energy Technology Data Exchange (ETDEWEB)
Hosseini, S.A. [Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz (Iran, Islamic Republic of); Ranjbar, Khalil, E-mail: firstname.lastname@example.com [Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz (Iran, Islamic Republic of); Dehmolaei, R. [Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz (Iran, Islamic Republic of); Amirani, A.R. [12th Ghaem Street, Bld. Hashemzadeh, Shahrak Golestan, Tehran (Iran, Islamic Republic of)
Highlights: • Using friction stir processing, an effect of CNTs and CeO{sub 2} reinforcements on mechanical and corrosion properties of Al5083 alloy is reported. • The strength of Al5083 was increased by 42%, its matrix grain size reduced five times, and hardness was doubled by the incorporation of CNTs-CeO{sub 2} mixture in the volume ratio of 75-25 respectively. • Unlike the CNTs, incorporation of nanosized CeO{sub 2} particles resulted in remarkable increase in pitting resistance of the alloy. - Abstract: In the present investigation, friction stir processing (FSP) was utilized to incorporate Multi Walled Carbon Nano Tubes (MWCNT) and nanosized cerium oxide particles into the matrix of Al5083 alloy to form surface reinforced composites. The effect of these nanosized reinforcements either separately or in the combined form, on microstructural modification, mechanical properties and corrosion resistance of FSPed Al5083 surface composites was studied. A threaded cylindrical hardened steel tool was used with the rotation speeds of 600 and 800 rpm and travel speeds of 35 and 45 mm/min and a tilt angle of 5°. Mechanical properties and corrosion resistance of FSPed samples were evaluated and compared with the base alloy. The maximum tensile strength and hardness value were achieved for the hybrid composite containing a mixture of CNTs and cerium oxide in the volume ratio of 75-25, respectively, whereas a significant increase in pitting resistance of the base alloy was obtained when cerium oxide alone was incorporated. The corrosion behavior of the samples was investigated by potentiodynamic polarization tests and assessed in term of pitting potential and passivation range. Microstructural analysis carried out by using optical and electron microscopes showed that reinforcements are well dispersed inside the nugget zone (NZ), and remarkable grain refinement is gained. The study was aimed to fabricate surface composites with improved mechanical properties and
Energy Technology Data Exchange (ETDEWEB)
Paul Tubel
The development work during this quarter was focused in the assembly of the downhole power generator hardware and its electronics module. The quarter was also spent in the development of the surface system electronics and software to extract the acoustic data transmitted from downhole to the surface from the noise generated by hydrocarbon flow in wells and to amplify very small acoustic signals to increase the distance between the downhole tool and the surface receiver. The tasks accomplished during this report period were: (1) Assembly of the downhole power generator mandrel for generation of electrical power due to flow in the wellbore. (2) Test the piezoelectric wafers to assure that they are performing properly prior to integrating them to the mechanical power generator mandrel. (3) Coat the power generator wafers to prevent water from shorting the power generator wafers. (4) Test of the power generator using a water tower and an electric pump to create a water flow loop. (5) Test the power harvesting electronics module. (6) Upgrade the signal condition and amplification from downhole into the surface system. (7) Upgrade the surface processing system capability to process data faster. (8) Create a new filtering technique to extract the signal from noise after the data from downhole is received at the surface system.
High power fast ramping power supplies
Energy Technology Data Exchange (ETDEWEB)
Marneris,I.; Bajon, E.; Bonati, R.; Sandberg, J.; Roser, T.; Tsoupas, N.
Hundred megawatt level fast ramping power converters to drive proton and heavy ion machines are under research and development at accelerator facilities in the world. This is a leading edge technology. There are several topologies to achieve this power level. Their advantages and related issues will be discussed.
Power, stability of power, and creativity
Sligte, D.J.; de Dreu, C.K.W.; Nijstad, B.A.
Power hierarchies are an essential aspect of social organization, create stability and social order, and provide individuals with incentives to climb the hierarchical ladder. Extending previous work on power and creativity, we put forward that this relationship critically depends on both the
Power, stability of power, and creativity
Sligte, Daniel J.; de Dreu, Carsten K. W.; Nijstad, Bernard A.
Power hierarchies are an essential aspect of social organization, create stability and social order, and provide individuals with incentives to climb the hierarchical ladder. Extending previous work on power and creativity, we put forward that this relationship critically depends on both the
Green Power Partnership 100 Green Power Users
EPA's Green Power Partnership is a voluntary program designed to reduce the environmental impact of electricity generation by promoting renewable energy. Partners on this list use green power to meet 100 of their U.S. organization-wide electricity use.
Active Power Control from Wind Power (Presentation)
Energy Technology Data Exchange (ETDEWEB)
Ela, E.; Brooks, D.
In order to keep the electricity grid stable and the lights on, the power system relies on certain responses from its generating fleet. This presentation evaluates the potential for wind turbines and wind power plants to provide these services and assist the grid during critical times.
Reactive Power Management in Electric Power Systems
African Journals Online (AJOL)
The quality of electric power at a supply point can be quantified in terms of how stab)e are the voltage and frequency and how close is the power factor to unity. The continuity of supply and in three-phase systems the degree to which the phase currents and voltages are balanced constitute additional quality parameters.
International Nuclear Information System (INIS)
Hudina, M.
For the determination of the thermal-hydraulic performances of rough surfaces, the method of evaluation is particularly important. In order to increase confidence in the results, a new evaluation procedure was introduced. This procedure is based on the transformation of simple channel experimental results to equal boundary conditions, and on the suitable application and confirmation of these transformed values in more complicated flow channel geometries. Existing methods, applied to the results obtained in an annular channel, do not fulfil all the transformation requirements. Thus a new, more complete transformation method, which uses the turbulent eddy diffusivity model, was developed. To check the quality of this transformation, within the scope of the new evaluation procedure, the results of experimental investigation in annular channels and in a bundle of hexagonal geometry were used together with the predictions of benchmark calculations. The success of the new method was confirmed by extensive comparisons, with the results of different presently-acknowledged transformations being considered as well. Based on these comparisons an assessment of the individual transformations is given. (Auth.)
Space structures, power, and power conditioning; Proceedings of the Meeting, Los Angeles, CA, Jan. 11-13, 1988
International Nuclear Information System (INIS)
Askew, R.F.
Various papers on space structures, power, and power conditioning are presented. Among the topics discussed are: heterogeneous gas core reaction for space nuclear power, pulsed gas core reactor for burst power, fundamental considerations of gas core reactor systems, oscillating thermionic conversion for high-density space power, thermoelectromagnetic pumps for space nuclear power systems, lightweight electrochemical converter for space power applications, ballistic acceleration by superheated hydrogen, laser-induced current switching in gaseous discharge, electron-beam-controlled semiconductor switches, laser-controlled semiconductor closing and opening switch. Also addressed are: semiconductor-metal eutectic composites for high-power switching, optical probes for the characterization of surface breakdown, 40 kV/20 kA pseudospark switch for laser applications, insulation direction for high-power space systems, state space simulation of spacecraft power systems, structural vibration of space power station systems, minimum-time control of large space structures, novel fusion reaction for space power and propulsion, repetition rate system evaluations, cryogenic silicon photoconductive switches for high-power lasers, multilevel diamondlike carbon capacitor structure, surface breakdown of prestressed insulators, C-Mo and C-Zr alloys for space power systems, magnetic insulation for the space environment
Solids-based concentrated solar power receiver
Energy Technology Data Exchange (ETDEWEB)
A concentrated solar power (CSP) system includes channels arranged to convey a flowing solids medium descending under gravity. The channels form a light-absorbing surface configured to absorb solar flux from a heliostat field. The channels may be independently supported, for example by suspension, and gaps between the channels are sized to accommodate thermal expansion. The light absorbing surface may be sloped so that the inside surfaces of the channels proximate to the light absorbing surface define downward-slanting channel floors, and the flowing solids medium flows along these floors. Baffles may be disposed inside the channels and oriented across the direction of descent of the flowing solids medium. The channels may include wedge-shaped walls forming the light-absorbing surface and defining multiple-reflection light paths for solar flux from the heliostat field incident on the light-absorbing surface.
International Nuclear Information System (INIS)
Geis, J.W.
This paper discusses a Space Power Subsystem Sizing program which has been developed by the Aerospace Power Division of Wright Laboratory, Wright-Patterson Air Force Base, Ohio. The Space Power Subsystem program (SPSS) contains the necessary equations and algorithms to calculate photovoltaic array power performance, including end-of-life (EOL) and beginning-of-life (BOL) specific power (W/kg) and areal power density (W/m 2 ). Additional equations and algorithms are included in the spreadsheet for determining maximum eclipse time as a function of orbital altitude, and inclination. The Space Power Subsystem Sizing program (SPSS) has been used to determine the performance of several candidate power subsystems for both Air Force and SDIO potential applications. Trade-offs have been made between subsystem weight and areal power density (W/m 2 ) as influenced by orbital high energy particle flux and time in orbit
Strelan, Peter; Weick, Mario; Vasiljevic, Milica
We took an individual differences approach to explain revenge tendencies in powerholders. Across four experimental studies, chronically powerless individuals sought more revenge than chronically powerful individuals following a high power episode (Studies 1 and 2), when striking a powerful pose (Study 3), and when making a powerful hand gesture (Study 4). This relationship vanished when participants were not exposed to incidental power. A meta-analysis revealed that, relative to a lack of power or a neutral context, exposure to incidental power increased vengeance among the chronically powerless and reduced vengeance among the chronically powerful. These findings add to previous research on relations between power and aggression, and underscore the role of individual differences as a determinant of powerholders' destructive responses. © 2013 The British Psychological Society.
Indirect drive targets for fusion power
Energy Technology Data Exchange (ETDEWEB)
Amendt, Peter A.; Miles, Robin R.
A hohlraum for an inertial confinement fusion power plant is disclosed. The hohlraum includes a generally cylindrical exterior surface, and an interior rugby ball-shaped surface. Windows over laser entrance holes at each end of the hohlraum enclose inert gas. Infrared reflectors on opposite sides of the central point reflect fusion chamber heat away from the capsule. P2 shields disposed on the infrared reflectors help assure an enhanced and more uniform x-ray bath for the fusion fuel capsule.
reactivated, resulting in algae in the tanks and tank seepage. This has led to degraded fuel quality and fuel leakage into ship's storerooms. The inherent...The cosmetic bulkhead is smooth like line 1; only 1 % of the reflected power is reflected along the sea surface. 4. Angled Bulkhead around Fantail... algae present and require continuous treatment to prevent fouling of the main engines and generators. The ship s tank system was not properly
High-power optics lasers and applications
Apollonov, Victor V
This book covers the basics, realization and materials for high power laser systems and high power radiation interaction with matter. The physical and technical fundamentals of high intensity laser optics and adaptive optics and the related physical processes in high intensity laser systems are explained. A main question discussed is: What is power optics? In what way is it different from ordinary optics widely used in cameras, motion-picture projectors, i.e., for everyday use? An undesirable consequence of the thermal deformation of optical elements and surfaces was discovered during studies of the interaction with powerful incident laser radiation. The requirements to the fabrication, performance and quality of optical elements employed within systems for most practical applications are also covered. The high-power laser performance is generally governed by the following: (i) the absorption of incident optical radiation (governed primarily by various absorption mechanisms), (ii) followed by a temperature ...
Trade studies for nuclear space power systems
International Nuclear Information System (INIS)
Smith, J.M.; Bents, D.J.; Bloomfield, H.S.
As human visions of space applications expand and as we probe further out into the universe, our needs for power will also expand, and missions will evolve which are enabled by nuclear power. A broad spectrum of missions which are enhanced or enabled by nuclear power sources have been defined. These include Earth orbital platforms, deep space platforms, planetary exploration, and terrestrial resource exploration. The recently proposed Space Exploration Initiative (SEI) to the Moon and Mars has more clearly defined these missions and their power requirements. Presented here are results of recent studies of radioisotope and nuclear reactor energy sources, combined with various energy conversion devices for Earth orbital applications, SEI lunar/Mars rovers, surface power, and planetary exploration
International Nuclear Information System (INIS)
Dlouhy, Z.
Main sources and characteristics of wastes are discussed and basic data are given on the amount and nature of all wastes produced during the treatment of liquid and gaseous wastes in nuclear power plants with boiling (BWR), pressurized (PWR), and advanced gas-cooled (MGR) reactors of a 1,000 MW(e) installed power. A short comparison of methods used for liquid radioactive waste treatment is given. Methods are shortly described for solidification of concentrates, sludges, resin slurries, and for immobilization of radioactive substances in other solid wastes. An approach to the problem of waste storage in a densely populated country is given. The part dealing with surface decontamination problems is dedicated to contaminant sources in gas and water-cooled reactors, to decontaminating agents used in reactor technology, and to the description of most important methods used in decontamination practice. A short evaluation of protective coatings from the point of view of their further successful decontamination is given. (orig./HK) [de
Energy Technology Data Exchange (ETDEWEB)
Muoniovaara, M. [IVO International Ltd, Vantaa (Finland)
IVO International is a major constructor of biomass power plants in Finland and abroad. As a subsidiary of Imatran Voima Oy, the largest power utility in Finland, it has designed and constructed ten power plants owned by IVO Group or others capable of burning biomasses. Sizes of the plants vary from the world`s largest condensing peat-fired power plant of 155 MWe to a 6 MWe combined heat and power producing unit. This article describes the biomass power plants designed and constructed by IVO Group 3 refs.
Shipboard electrical power systems
Patel, Mukund R
Shipboard Electrical Power Systems addresses new developments in this growing field. Focused on the trend toward electrification to power commercial shipping, naval, and passenger vessels, this book helps new or experienced engineers master cutting-edge methods for power system design, control, protection, and economic use of power. Provides Basic Transferable Skills for Managing Electrical Power on Ships or on LandThis groundbreaking book is the first volume of its kind to illustrate optimization of all aspects of shipboard electrical power systems. Applying author Mukund Patel's rare combina
Nuclear power economic database
International Nuclear Information System (INIS)
Ding Xiaoming; Li Lin; Zhao Shiping
Nuclear power economic database (NPEDB), based on ORACLE V6.0, consists of three parts, i.e., economic data base of nuclear power station, economic data base of nuclear fuel cycle and economic database of nuclear power planning and nuclear environment. Economic database of nuclear power station includes data of general economics, technique, capital cost and benefit, etc. Economic database of nuclear fuel cycle includes data of technique and nuclear fuel price. Economic database of nuclear power planning and nuclear environment includes data of energy history, forecast, energy balance, electric power and energy facilities
Weedy, B M; Jenkins, N; Ekanayake, J B; Strbac, G
The definitive textbook for Power Systems students, providing a grounding in essential power system theory while also focusing on practical power engineering applications. Electric Power Systems has been an essential book in power systems engineering for over thirty years. Bringing the content firmly up-to-date whilst still retaining the flavour of Weedy's extremely popular original, this Fifth Edition has been revised by experts Nick Jenkins, Janaka Ekanayake and Goran Strbac. This wide-ranging text still covers all of the fundamental power systems subjects but is now e
Complete Surface Mapping of ICF Shells
International Nuclear Information System (INIS)
Stephens, R.B.; Olson, D.; Huang, H.; Gibson, J.B.
Inertial confinement fusion shells have previously been evaluated on the basis of microscopic examination for local defects and limited surface profiling to represent their average fluctuation power. Since defects are local, and don't always have visible edges, this approach both misses some important fluctuations and doesn't properly represent the spatially dependent surface fluctuation power. We have taken the first step toward correcting this problem by demonstrating the capability to completely map the surface of a NIF shell with the resolution to account for all modes. This allows complete accounting of all the surface fluctuations. In the future this capability could be used for valuable shells to generate a complete r(θ, φ) surface map for accurate 3-D modeling of a shot
International Nuclear Information System (INIS)
OAK-B135 Inertial confinement fusion shells have previously been evaluated on the basis of microscopic examination for local defects and limited surface profiling to represent their average fluctuation power. Since defects are local, and don't always have visible edges, this approach both misses some important fluctuations and doesn't properly represent the spatially dependent surface fluctuation power. they have taken the first step toward correcting this problem by demonstrating the capability to completely map the surface of a NIF shell with the resolution to account for all modes. This allows complete accounting of all the surface fluctuations. In the future this capability could be used for valuable shells to generate a complete r(θ,ψ) surface map for accurate 3-D modeling of a shot
Photovoltaic Power System and Power Distribution Demonstration for the Desert RATS Program
Colozza, Anthony; Jakupca, Ian; Mintz, Toby; Herlacher, Mike; Hussey, Sam
A stand alone, mobile photovoltaic power system along with a cable deployment system was designed and constructed to take part in the Desert Research And Technology Studies (RATS) lunar surface human interaction evaluation program at Cinder Lake, Arizona. The power system consisted of a photovoltaic array/battery system. It is capable of providing 1 kW of electrical power. The system outputs were 48 V DC, 110 V AC, and 220 V AC. A cable reel with 200 m of power cable was used to provide power from the trailer to a remote location. The cable reel was installed on a small trailer. The reel was powered to provide low to no tension deployment of the cable. The cable was connected to the 220 V AC output of the power system trailer. The power was then converted back to 110 V AC on the cable deployment trailer for use at the remote site. The Scout lunar rover demonstration vehicle was used to tow the cable trailer and deploy the power cable. This deployment was performed under a number of operational scenarios, manned operation, remote operation and tele-robotically. Once deployed, the cable was used to provide power, from the power system trailer, to run various operational tasks at the remote location.
Physical protection of power reactors
International Nuclear Information System (INIS)
Darby, J.L.
Sandia Laboratories has applied a systematic approach to designing physical protection systems for nuclear facilities to commercial light-water reactor power plants. A number of candidate physical protection systems were developed and evaluated. Focus is placed on the design of access control subsystems at each of three plant layers: the protected area perimeter, building surfaces, and vital areas. Access control refers to barriers, detectors, and entry control devices and procedures used to keep unauthorized personnel and contraband out of the plant, and to control authorized entry into vital areas within the plant
Self powered pacers and stimulators
International Nuclear Information System (INIS)
Rasor, N.S.; Spickler, J.W.
A simulator device is described for insertion in a living body, having particular advantage for intracardiac use comprising a housing having a body formed for transvenous or transarterial insertion, electrode means at the outer surface of said body, means included in said housing defining a pulsing circuit electrically connected with said electrode means and means for activating said pulsing circuit embodied in said housing, said activating means being free of physical connection with an outside power source and dependent for its function on the living body in which it is inserted
Next Generation Geothermal Power Plants
Energy Technology Data Exchange (ETDEWEB)
Brugman, John; Hattar, Mai; Nichols, Kenneth; Esaki, Yuri
A number of current and prospective power plant concepts were investigated to evaluate their potential to serve as the basis of the next generation geothermal power plant (NGGPP). The NGGPP has been envisaged as a power plant that would be more cost competitive (than current geothermal power plants) with fossil fuel power plants, would efficiently use resources and mitigate the risk of reservoir under-performance, and minimize or eliminate emission of pollutants and consumption of surface and ground water. Power plant concepts were analyzed using resource characteristics at ten different geothermal sites located in the western United States. Concepts were developed into viable power plant processes, capital costs were estimated and levelized busbar costs determined. Thus, the study results should be considered as useful indicators of the commercial viability of the various power plants concepts that were investigated. Broadly, the different power plant concepts that were analyzed in this study fall into the following categories: commercial binary and flash plants, advanced binary plants, advanced flash plants, flash/binary hybrid plants, and fossil/geothed hybrid plants. Commercial binary plants were evaluated using commercial isobutane as a working fluid; both air-cooling and water-cooling were considered. Advanced binary concepts included cycles using synchronous turbine-generators, cycles with metastable expansion, and cycles utilizing mixtures as working fluids. Dual flash steam plants were used as the model for the commercial flash cycle. The following advanced flash concepts were examined: dual flash with rotary separator turbine, dual flash with steam reheater, dual flash with hot water turbine, and subatmospheric flash. Both dual flash and binary cycles were combined with other cycles to develop a number of hybrid cycles: dual flash binary bottoming cycle, dual flash backpressure turbine binary cycle, dual flash gas turbine cycle, and binary gas turbine
A Comparison Of A Solar Power Satellite Concept To A Concentrating Solar Power System
Smitherman, David V.
A comparison is made of a Solar Power Satellite concept in geostationary Earth orbit to a Concentrating Solar Power system on the ground to analyze overall efficiencies of each infrastructure from solar radiance at 1 AU to conversion and transmission of electrical energy into the power grid on the Earth's surface. Each system is sized for a 1-gigawatt output to the power grid and then further analyzed to determine primary collector infrastructure areas. Findings indicate that even though the Solar Power Satellite concept has a higher end-to-end efficiency, that the combined space and ground collector infrastructure is still about the same size as a comparable Concentrating Solar Power system on the ground.