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Office of Scientific and Technical Information
A general kinetic model: Kinetics and atomic-scale mechanisms of feldspar dissolution.
E-Print Network (OSTI)
??This thesis presents a general kinetic model and its application to feldspar dissolution. In the framework of Monte Carlo methods, the model simulates the stochastic� (more)
Zhang, Li
Exposure chamber
DOE Patents (OSTI)
A chamber for exposing animals, plants, or materials to air containing gases or aerosols is so constructed that catch pans for animal excrement, for example, serve to aid the uniform distribution of air throughout the chamber instead of constituting obstacles as has been the case in prior animal exposure chambers. The chamber comprises the usual imperforate top, bottom and side walls. Within the chamber, cages and their associated pans are arranged in two columns. The pans are spaced horizontally from the walls of the chamber in all directions. Corresponding pans of the two columns are also spaced horizontally from each other. Preferably the pans of one column are also spaced vertically from corresponding pans of the other column. Air is introduced into the top of the chamber and withdrawn from the bottom. The general flow of air is therefore vertical. The effect of the horizontal pans is based on the fact that a gas flowing past the edge of a flat plate that is perpendicular to the flow forms a wave on the upstream side of the plate. Air flows downwardly between the chamber walls and the outer edges of the pan. It also flows downwardly between the inner edges of the pans of the two columns. It has been found that when the air carries aerosol particles, these particles are substantially uniformly distributed throughout the chamber.
Moss, Owen R. (Kennewick, WA)
Wire chamber
A wire chamber or proportional counter device, such as Geiger-Mueller tube or drift chamber, improved with a gas mixture providing a stable drift velocity while eliminating wire aging caused by prior art gas mixtures. The new gas mixture is comprised of equal parts argon and ethane gas and having approximately 0.25% isopropyl alcohol vapor.
Atac, Muzaffer (Wheaton, IL)
Band-trap capture and emission in the generalized kinetic theory of electrons and holes
of the applications. These assumptions amount to discard the kinetic equation for phonons, and to replace np The Boltzmann Equation and its Applications (New York: Springer Verlag). [8] Spiga G 1992 On extended kinetic theory with chemical reaction Nonlinear Kinetic Theory and Mathematical Aspects of Hyperbolic Systems ed
Spiga, Giampiero
This patent describes a novel ionization chamber which is well suited to measuring the radioactivity of the various portions of a wire as the wire is moved at a uniform speed, in order to produce the neutron flux traverse pattern of a reactor in which the wire was previously exposed to neutron radiation. The ionization chamber of the present invention is characterized by the construction wherein the wire is passed through a tubular, straight electrode and radiation shielding material is disposed along the wire except at an intermediate, narrow area where the second electrode of the chamber is located.
Redman, W.C.; Shonka, F.R.
Ionization chamber
An ionization chamber has separate drift and detection regions electrically isolated from each other by a fine wire grid. A relatively weak electric field can be maintained in the drift region when the grid and another electrode in the chamber are connected to a high voltage source. A much stronger electric field can be provided in the detection region by connecting wire electrodes therein to another high voltage source. The detection region can thus be operated in a proportional mode when a suitable gas is contained in the chamber. High resolution output pulse waveforms are provided across a resistor connected to the detection region anode, after ionizing radiation enters the drift region and ionize the gas.
Walenta, Albert H. (Port Jefferson Station, NY)
Chamber propagation
SciTech Connect
Propagation of a heavy ion beam to the target appears possible under conditions thought to be realizable by several reactor designs. Beam quality at the lens is believed to provide adequate intensity at the target -- but the beam must pass through chamber debris and its self fields along the way. This paper reviews present consensus on propagation modes and presents recent results on the effects of photoionization of the beam ions by thermal x-rays from the heated target. Ballistic propagation through very low densities is a conservative mode. The more-speculative self-pinched mode, at 1 to 10 Torr, offers reactor advantages and is being re-examined by others. 13 refs.
Langdon, B.
Glossary Term - Cloud Chamber
NLE Websites -- All DOE Office Websites (Extended Search)
Ceres Previous Term (Ceres) Glossary Main Index Next Term (Composition of the Earth's Atmosphere) Composition of theEarth's Atmosphere Cloud Chamber A cloud chamber showing the...
The Balance of Kinetic and Total Energy Simulated by the OSU Two-Level Atmospheric General Circulation Model for January and July
Science Conference Proceedings (OSTI)
The horizontal structure of the balances of kinetic energy and total energy simulated by the Oregon State University (OSU) two-level atmospheric general circulation model are studied for January and July on the basis of a three-year simulation ...
Jough-Tai Wang; Jeong-Woo Kim; W. Lawrence Gates
A reaction-based paradigm to model reactive chemical transport in groundwater with general kinetic and equilibrium reactions
This paper presents a reaction-based water quality transport model in subsurface flow systems. Transport of chemical species with a variety of chemical and physical processes is mathematically described by M partial differential equations (PDEs). Decomposition via Gauss-Jordan column reduction of the reaction network transforms M species reactive transport equations into two sets of equations: a set of thermodynamic equilibrium equations representing NE equilibrium reactions and a set of reactive transport equations of M-NE kinetic-variables involving no equilibrium reactions (a kinetic-variable is a linear combination of species). The elimination of equilibrium reactions from reactive transport equations allows robust and efficient numerical integration. The model solves the PDEs of kinetic-variables rather than individual chemical species, which reduces the number of reactive transport equations and simplifies the reaction terms in the equations. A variety of numerical methods are investigated for solving the coupled transport and reaction equations. Simulation comparisons with exact solutions were performed to verify numerical accuracy and assess the effectiveness of various numerical strategies to deal with different application circumstances. Two validation examples involving simulations of uranium transport in soil columns are presented to evaluate the ability of the model to simulate reactive transport with complex reaction networks involving both kinetic and equilibrium reactions.
Zhang, Fan [ORNL; Yeh, Gour-Tsyh [University of Central Florida, Orlando; Parker, Jack C [ORNL; Brooks, Scott C [ORNL; Pace, Molly [ORNL; Kim, Young Jin [ORNL; Jardine, Philip M [ORNL; Watson, David B [ORNL
Hupmobile cloud chamber parameters
The accompanying table lists the presently selected parameters for the twelve cloud chambers. The chambers are numbered consecutively from 4 through 15 as they are lined up in the bunker. The lowest number is closest to the source. All except the first chamber have some thin metal filters to attenuate the flux and harden the spectrum. Cloud chambers 10, 12, and 14 are shielded by a collimator with about 200 pinholes in it. The flux in these chambers is attenuated by the ratio of the pinhole area to total beam area which is a factor of 50. Various gases and gas pressures are used to obtain suitable track lengths and interaction cross sections. Neon, argon, and krypton are used to obtain photo electrons. Hydrogen is used to obtain Compton electrons.
Hansen, N. E.
The Environmental Chamber
2 2 The Environmental Chamber Al Hodgson and Richard Allen test methyl chloride exposures using the environmental chamber. On the second floor of an unremarkable building at LBL, researchers are using a room within a room to smoke out indoor air pollutants. The environmental chamber is a stainless-steel-lined room of 540 ft cubed (20 meters cubed) which can be operated in several ways to meet the needs of different research projects, including studies for which a very low background is required. Scientists of the Indoor Environment Program and their collaborators use the chamber as a controlled indoor environment to study the behavior of a variety of indoor pollutants ranging from cigarette smoke to volatile organic compounds (VOCs) from new carpets. At the moment, four projects use the facility. Principal investigator Al
Sleeve reaction chamber system
A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.
Northrup, M. Allen (Berkeley, CA); Beeman, Barton V. (San Mateo, CA); Benett, William J. (Livermore, CA); Hadley, Dean R. (Manteca, CA); Landre, Phoebe (Livermore, CA); Lehew, Stacy L. (Livermore, CA); Krulevitch, Peter A. (Pleasanton, CA)
Photo of Spray Combustion Chamber
NIST Spray Combustion Chamber. NIST, National Institute of Standards and Technology, Material Measurement Laboratory, ...
CALCULATION OF PULSED KICKER MAGNETIC FIELD ATTENUATION CALCULATION OF PULSED KICKER MAGNETIC FIELD ATTENUATION INSIDE BEAM CHAMBERS S. H. Kim January 8, 2001 1. Introduction and Summary The ceramic beam chambers in the sections of the kicker magnets for the beam injection and extraction in the Advanced Photon Source (APS) are made of alumina. The inner surface of the ceramic chamber is coated with a conductive paste. The choice of coating thickness is intended to reduce the shielding of the pulsed kicker magnetic field while containing the electromagnetic fields due to the beam bunches inside the chamber, and minimize the Ohmic heating due to the fields on the chamber [1]. The thin coating generally does not give a uniform surface resistivity for typical dimensions of the ceramic chambers in use. The chamber cross section is a circular or
Kinetic equilibrium and relativistic thermodynamics
Relativistic thermodynamics is treated from the point of view of kinetic theory. It is shown that the generalized J\\"uttner distribution suggested in [1] is compatible with kinetic equilibrium. The requirement of compatibility of kinetic and thermodynamic equilibrium reveals several generalizations of the Gibbs relation where the velocity field is an independent thermodynamic variable.
P. V�n
V�n, P
A Generalized Biomass Pyrolysis Model Based on Superimposed Cellulose, IIemi-CCIIU1OSC and Lignin Kinetics
this paper is to present a model for the numerical simulation of macro-particle of general of the is to predict pyrolysis yields associated with "typical" biomass samples. Potential alterations necessary to account for mineral and moisture content pressure arc postponed for future work. A ncw based on superimposed CC1IU1OSC,
R. S. Miller; J. Bellan; I. Ignin Kinetics; J. Bj. An; Jd Iyqmlsion; Greek Syqbols
A Comparison of Baroclinic Instability with the Time Variations of Kinetic Energy in a General Circulation Model
The flow generated by a general circulation model is zonally averaged at 1-day intervals, and, for each of the axisymmetric flows obtained, the linear growth-rate spectrum for baroclinic waves is computed using a linear model. The time sequence ...
Robert Walko; Robert Gall
Improved wire chamber
An improved gas mixture for use with proportional counter devices, such as Geiger-Mueller tubes and drift chambers. The improved gas mixture provides a stable drift velocity while eliminating wire aging caused by prior art gas mixtures. The new gas mixture is comprised of equal parts argon and ethane gas and having approximately 0.25% isopropyl alcohol vapor. 2 figs.
Atac, M.
Miniature reaction chamber and devices incorporating same
The present invention generally relates to miniaturized devices for carrying out and controlling chemical reactions and analyses. In particular, the present invention provides devices which have miniature temperature controlled reaction chambers for carrying out a variety of synthetic and diagnostic applications, such as PCR amplification, nucleic acid hybridization, chemical labeling, nucleic acid fragmentation and the like.
Mathies, Richard A. (Moraga, CA); Woolley, Adam T. (Albany, CA)
Multi-chamber deposition system
A system for the simultaneous deposition of different coatings onto a thin web within a large volume vacuum chamber is disclosed which chamber is provided with a plurality of deposition chambers in which the different layers are deposited onto the film as its moves from a supply roll to a finished take-up roll of coated web. The deposition chambers provided within the large vacuum chamber are provided with separate seals which minimize back diffusion of any dopant gas from adjacent deposition chambers.
Jacobson, Richard L. (Roseville, MN); Jeffrey, Frank R. (Shoreview, MN); Westerberg, Roger K. (Cottage Grove, MN)
Three chamber negative ion source
A negative ion vessel is divided into an excitation chamber, a negative ionization chamber and an extraction chamber by two magnetic filters. Input means introduces neutral molecules into a first chamber where a first electron discharge means vibrationally excites the molecules which migrate to a second chamber. In the second chamber a second electron discharge means ionizes the molecules, producing negative ions which are extracted into or by a third chamber. A first magnetic filter prevents high energy electrons from entering the negative ionization chamber from the excitation chamber. A second magnetic filter prevents high energy electrons from entering the extraction chamber from the negative ionizing chamber. An extraction grid at the end of the negative ion vessel attracts negative ions into the third chamber and accelerates them. Another grid, located adjacent to the extraction grid, carries a small positive voltage in order to inhibit positive ions from migrating into the extraction chamber and contour the plasma potential. Additional electrons can be suppressed from the output flux using ExB forces provided by magnetic field means and the extractor grid electric potential.
Leung, Ka-Ngo (Hercules, CA); Ehlers, Kenneth W. (Alamo, CA); Hiskes, John R. (Livermore, CA)
A radiation detector of the bubble chamber class is described which is continuously sensitive and which does not require the complex pressure cycling equipment characteristic of prior forms of the chamber. The radiation sensitive element is a gas-saturated liquid and means are provided for establishing a thermal gradient across a region of the liquid. The gradient has a temperature range including both the saturation temperature of the liquid and more elevated temperatures. Thus a supersaturated zone is created in which ionizing radiations may give rise to visible gas bubbles indicative of the passage of the radiation through the liquid. Additional means are provided for replenishing the supply of gas-saturated liquid to maintaincontinuous sensitivity.
Good, R.H.
Argus target chamber
A target chamber for application in the laser fusion program must satisfy some very basic requirements. (1) Provide a vacuum on the order of 10$sup -6$ torr. (2) Support a microscopically small target in a fixed point in space and verify its location within 5 micrometers. (3) Contain an adjustable beam focusing system capable of delivering a number of laser beams onto the target simultaneously, both in time and space. (4) Provide access for diagnostics to evaluate the results of target irradiation. (5) Have flexibility to allow changes in targets, focusing optics and number of beams. The ARGUS laser which is now under construction at LLL will have a target chamber which meets these requirements in a simple economic manner. The chamber and auxiliary equipment are described, with reference to two double beam focusing systems; namely, lenses and ellipsoidal mirrors. Provision is made for future operation with four beams, using ellipsoidal mirrors for two-sided illumination and lens systems for tetragonal and tetrahedral irradiation. (auth)
Rienecker, F. Jr.; Glaros, S.S.; Kobierecki, M.
Vertical two chamber reaction furnace
A vertical two chamber reaction furnace is disclosed. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700 and 800 C) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800 to 950 C to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product. 2 figs.
Blaugher, R.D.
Multi-anode ionization chamber
The present invention includes a high-energy detector having a cathode chamber, a support member, and anode segments. The cathode chamber extends along a longitudinal axis. The support member is fixed within the cathode chamber and extends from the first end of the cathode chamber to the second end of the cathode chamber. The anode segments are supported by the support member and are spaced along the longitudinal surface of the support member. The anode segments are configured to generate at least a first electrical signal in response to electrons impinging thereon.
Bolotnikov, Aleksey E. (South Setauket, NY); Smith, Graham (Port Jefferson, NY); Mahler, George J. (Rocky Point, NY); Vanier, Peter E. (Setauket, NY)
Application of chemical kinetic modeling to improve design and performance criteria for a practical incineration system.
??In this study, detailed thermo-chemical kinetics with networked ideal reactor model were applied to simulate a practical combustion system -the Secondary Combustion Chamber (SCC) of� (more)
Bass, Jr., Charles A.
HVAC&R Equipment Environmental Chambers
... with relative humidity controlled within �2 %. Small Appliance and Refrigerator Chamber. This chamber is used to test small ...
Operation of an apparatus for analysis of solutions by the Lundegardh flame technique was greatiy facilituted by the modification of a spray chamber. Samples can be introduced and removed from the modified spray chamber without extinguishing the flame or dismantling the assembly. (auth)
Palin, P.C.
LRL 25-inch Bubble Chamber
DOE R&D Accomplishments (OSTI)
The recently completed 25-inch hydrogen bubble chamber combines excellent picture quality with a fast operating cycle. The chamber has a unique optical system and is designed to take several pictures each Bevatron pulse, in conjunction with the Bevatron rapid beam ejection system.
Alvarez, L. W.; Gow, J. D.; Barrera, F.; Eckman, G.; Shand, J.; Watt, R.; Norgren, D.; Hernandez, H. P.
National Ignition Facility Target Chamber
DOE Green Energy (OSTI)
On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This was necessary to achieve the overall schedule. Plans had to be developed for the precise location and alignment of laser beam ports. Upon completion of the fabrication of the aluminum target chamber in a temporary structure the 130 ton sphere was moved from the temporary construction enclosure to its final location in the target building. Prior to the installation of a concrete shield and after completion of the welding of the chamber penetrations vacuum leak checking was performed to insure the vacuum integrity of target chamber. The entire spherical chamber external surface supports a 40 cm thick reinforced concrete shield after installation in the target building. The final task is a total survey of the laser ports and the contour machining of spacer plates so that laser devices attached to these ports meet the alignment criteria.
Wavrik, R W; Cox, J R; Fleming, P J
Application of Ice Nucleation Kinetics in Orographic Clouds
Ice nucleation by silver iodide-sodium iodide aerosol particles has been characterized in the Colorado State University isothermal cloud chamber using the techniques of chemical kinetics. Two separate mechanisms of condensation-freezing ice ...
Rochelle R. Blumenstein; Robert M. Rauber; Lewis O. Grant; William G. Finnegan
Humidity effects in ionization chambers
Capacitance variations due to humidity alterations have been suggested as the cause of ionization chamber current variations. The validity of the arguments is seriously questioned on several points. (auth)
Bengtsson, L.G.
Light diffusing fiber optic chamber
A light diffusion system for transmitting light to a target area. The light is transmitted in a direction from a proximal end to a distal end by an optical fiber. A diffusing chamber is operatively connected to the optical fiber for transmitting the light from the proximal end to the distal end and transmitting said light to said target area. A plug is operatively connected to the diffusing chamber for increasing the light that is transmitted to the target area.
Maitland, Duncan J. (Lafayette, CA)
Plasma chemistry in wire chambers
The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an {sup 55}Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed.
Wise, J.
The TESLA Time Projection Chamber
A large Time Projection Chamber is proposed as part of the tracking system for a detector at the TESLA electron positron linear collider. Different ongoing R&D studies are reviewed, stressing progress made on a new type readout technique based on Micro-Pattern Gas Detectors.
Nabil Ghodbane
Mass independent kinetic energy reducing inlet system for vacuum environment
A particle inlet system comprises a first chamber having a limiting orifice for an incoming gas stream and a micrometer controlled expansion slit. Lateral components of the momentum of the particles are substantially cancelled due to symmetry of the configuration once the laminar flow converges at the expansion slit. The particles and flow into a second chamber, which is maintained at a lower pressure than the first chamber, and then moves into a third chamber including multipole guides for electromagnetically confining the particle. The vertical momentum of the particles descending through the center of the third chamber is minimized as an upward stream of gases reduces the downward momentum of the particles. The translational kinetic energy of the particles is near-zero irrespective of the mass of the particles at an exit opening of the third chamber, which may be advantageously employed to provide enhanced mass resolution in mass spectrometry.
Reilly, Peter T. A. [Knoxville, TN
The determination of the amount of contamination remaining on a garment after it has been washed is an important part of hot laundry operations. In the past garments were monitored by measuring the contamination concentrated in the crotch with a GM tube probe. This type of spot check does not detect any isolated hot spots on other pants of the garment. To monitor the entire garment with a GM tube instrument is excessively time consuming for a large number of garments. To overcome these difficulties a sensitive, large-volume ionization chamber was constructed. It is rectangular in shape, 5 ft high by 2 1/2 ft wide by 4 in. deep. The center electrode is of a grid type and is mounted halfway between the front window and the back of the chamber. In a 0.5-mr/hr field, 180 v is sufficient to saturate toe chamber. In order to insure beta sensitivity, the front window has an equivalent thickness of approximately 7 mg/cm/sup 2/. The measuring device is a line-operated electrometer circuit equipped with an alarm that may be set at the rejection limit for the type of garment being monitored. A fullscale deflection on the most sensitive range is given by 2 to 3 mu C of liquid mixed fission products deposited on a garment. Since the chamber monitors the entire garment, the results are independent of the location of the contarnination. In practice, garments may be monitored at the rate of 7 per min, while only 3 per min may be completely checked with a GM tube probs. Field tests indicate that this instrument is stable and trouble free. Background causes a meter deflection of about 20 divisions, which is low enough to give reliable accuracy for monitoring garments. (auth)
Chester, J.D.; Handloser, J.S.
Chamber Comments on Cybersecurity Green Paper Final
... Using security disclosure as an incentive,� its authors ... The Chamber noted that incentives would prove more productive than regulation. ...
Noise Analysis of Statham Temperature Chamber
A procedure is described to subdue the noise made by the LN2 control valve on a Statham Temperature Chamber.
Mielke, R. L.
Kinetic Economies
We study a minimalist kinetic model for economies. A system of agents with local trading rules display emergent demand behaviour. We examine the resulting wealth distribution to look for non-thermal behaviour. We compare and contrast this model with other similar models.
Abdullah, Wan Ahmad Tajuddin Wan
Nonlinear effects in kinetic resolutions
The impact of nonlinear effects in the asymmetric catalysis of kinetic resolutions is analyzed. It is found with minimal assumptions that the kinetics of homocompetitive reactions should apply generally to kinetic resolutions involving partially resolved catalysts, and this is supported by experimental observations with the Jacobsen hydrolytic kinetic resolution (HKR) of epoxides. The criterion for a nonlinear effect in asymmetric catalysis--a nonlinear correlation between the enantiomeric excess in a choral ligand and the product enantiomeric excess obtained from a reaction--is examined. The nonlinear effect idea is found to be generalizable to kinetic resolutions and other reactions by replacing consideration of the product enantiomeric excess with the quantity (k[]/k[]-1)/(k[]/k[]+1), a differential kinetic enantiomeric enhancement (DKEE). A nonlinear effect may then be defined by a nonlinear correlation between the DKEE and the chiral ligand enantiomeric excess. The application of these ideas to previously reported kinetic resolutions of sulfoxides and to nonlinear effects in the Jacobsen HKR is described. Relatively small nonlinear effects in kinetic resolutions are sufficient to obtain large asymmetric amplifications. A catalyst modification in the Jacobsen HKR also allows for the development of a novel recyclable system for the iterative enhancement of optical activity.
Johnson, Derrell W.
Georges Charpak, Particle Detectors, and Multiwire Chambers
Georges Charpak, Particle Detectors, and Multiwire Chambers Georges Charpak, Particle Detectors, and Multiwire Chambers Resources with Additional Information · Patents Georges Charpak Courtesy of CERN Nobel laureate Georges Charpak [was] a pioneer in the art and science of particle detection ... . [He] developed a host of particle detectors used throughout experimental particle physics. In 1968, he invented and developed the first multiwire proportional chamber, for which he won the [Physics] Nobel Prize in 1992 ... . The multiwire chamber differed from earlier detectors in the speed with which it could record particle tracks from a collision-millions per second, rather than one or two per second for bubble chambers. The speed of the multiwire chamber and its successor technologies, along with their extraordinary precision, led to a revolution in particle physics ... . The technology that Charpak pioneered also finds applications in medicine and industry.
Fluidized wall for protecting fusion chamber walls
Apparatus for protecting the inner wall of a fusion chamber from microexplosion debris, x-rays, neutrons, etc. produced by deuterium-tritium (DT) targets imploded within the fusion chamber. The apparatus utilizes a fluidized wall similar to a waterfall comprising liquid lithium or solid pellets of lithium-ceramic, the waterfall forming a blanket to prevent damage of the structural materials of the chamber.
Maniscalco, James A. (Danville, CA); Meier, Wayne R. (Livermore, CA)
Insitu Oxygen Conduction Into Internal Combustion Chamber
Insitu Oxygen Conduction Into Internal Combustion Chamber Note: The technology described above is an early stage opportunity. Licensing rights to this ...
The Mark II Vertex Drift Chamber
We have completed constructing and begun operating the Mark II Drift Chamber Vertex Detector. The chamber, based on a modified jet cell design, achieves 30 {mu}m spatial resolution and <1000 {mu}m track-pair resolution in pressurized CO{sub 2} gas mixtures. Special emphasis has been placed on controlling systematic errors including the use of novel construction techniques which permit accurate wire placement. Chamber performance has been studied with cosmic ray tracks collected with the chamber located both inside and outside the Mark II. Results on spatial resolution, average pulse shape, and some properties of CO{sub 2} mixtures are presented. 10 refs., 12 figs., 1 tab.
Alexander, J.P.; Baggs, R.; Fujino, D.; Hayes, K.; Hoard, C.; Hower, N.; Hutchinson, D.; Jaros, J.A.; Koetke, D.; Kowalski, L.A.
On the property of measurements with the PTW microLion chamber in continuous beams
Purpose: The performance of liquid ionization chambers, which may prove to be useful tools in the field of radiation dosimetry, is based on several chamber and liquid specific characteristics. The present work investigates the performance of the PTW microLion liquid ionization chamber with respect to recombination losses and perturbations from ambient electric fields at various dose rates in continuous beams. Methods: In the investigation, experiments were performed using two microLion chambers, containing isooctane (C{sub 8}H{sub 18}) and tetramethylsilane [Si(CH{sub 3}){sub 4}] as the sensitive media, and a NACP-02 monitor chamber. An initial activity of approximately 250 GBq {sup 18}F was employed as the radiation source in the experiments. The initial dose rate in each measurement series was estimated to 1.0 Gy min{sup -1} by Monte Carlo simulations and the measurements were carried out during the decay of the radioactive source. In the investigation of general recombination losses, employing the two-dose-rate method for continuous beams, the liquid ionization chambers were operated at polarizing voltages 25, 50, 100, 150, 200, and 300 V. Furthermore, measurements were also performed at 500 V polarizing voltage in the investigation of the sensitivity of the microLion chamber to ambient electric fields. Results: The measurement results from the liquid ionization chambers, corrected for general recombination losses according to the two-dose-rate method for continuous beams, had a good agreement with the signal to dose linearity from the NACP-02 monitor chamber for general collection efficiencies above 70%. The results also displayed an agreement with the theoretical collection efficiencies according to the Greening theory, except for the liquid ionization chamber containing isooctane operated at 25 V. At lower dose rates, perturbations from ambient electric fields were found in the microLion chamber measurement results. Due to the perturbations, measurement results below an estimated dose rate of 0.2 Gy min{sup -1} were excluded from the present investigation of the general collection efficiency. The perturbations were found to be more pronounced when the chamber polarizing voltage was increased. Conclusions: By using the two-dose-rate method for continuous beams, comparable corrected ionization currents from experiments in low and medium energy photon beams can be achieved. However, the valid range of general collection efficiencies has been found to vary in a comparison between experiments performed in continuous beams of 120 kVp x ray, and the present investigation of 511 keV annihilation photons. At very high dose rates in continuous beams, there are presently no methods that can be used to correct for general recombination losses and at low dose rates the microLion chamber may be perturbed by ambient electric fields. Increasing the chamber polarizing voltage, which diminishes the general recombination effect, was found to increase the microLion chamber sensitivity to ambient electric fields. Prudence is thus advised when employing the microLion chamber in radiation dosimetry, as ambient electric fields of the strength observed in the present work may be found in many common situations. Due to uncertainties in the theoretical basis for recombination losses in liquids, further studies on the underlying theories for the initial and general recombination effect are needed if liquid ionization chambers are to become a viable option in high precision radiation dosimetry.
Andersson, Jonas; Johansson, Erik; Toelli, Heikki [Department of Radiation Sciences, Radiation Physics, Umea University, SE-901 85 Umea (Sweden); Swedish Defense Research Agency, FOI CBRN Defense and Security, SE-901 82 Umea (Sweden); Department of Radiation Sciences, Radiation Physics, Umea University, SE-901 85 Umea (Sweden)
IFE Chamber Technology Testing Program In NIF and Chamber Development Test Plan Mohamed A. Abdou
IFE Chamber Technology Testing Program In NIF and Chamber Development Test Plan Mohamed A. Abdou chamber technology testing program in NIF involoving: criteria for evaluation prior to NIF testing were addressed in this paper. In order to maximize the benefits of testing program
Abdou, Mohamed
Ionization-chamber smoke detector system
This invention relates to an improved smoke-detection system of the ionization-chamber type. In the preferred embodiment, the system utilizes a conventional detector head comprising a measuring ionization chamber, a reference ionization chamber, and a normally non-conductive gas triode for discharging when a threshold concentration of airborne particulates is present in the measuring chamber. The improved system is designed to reduce false alarms caused by fluctuations in ambient temperature. Means are provided for periodically firing the gas discharge triode and each time recording the triggering voltage required. A computer compares each triggering voltage with its predecessor. The computer is programmed to energize an alarm if the difference between the two compared voltages is a relatively large value indicative of particulates in the measuring chamber and to disregard smaller differences typically resulting from changes in ambient temperature.
Roe, Robert F. (Jackson, OH)
High Accuracy, Two-Dimensional Read-Out in Multiwire Proportional Chambers
In most applications of proportional chambers, especially in high-energy physics, separate chambers are used for measuring different coordinates. In general one coordinate is obtained by recording the pulses from the anode wires around which avalanches have grown. Several methods have been imagined for obtaining the position of an avalanche along a wire. In this article a method is proposed which leads to the same range of accuracies and may be preferred in some cases. The problem of accurate measurements for large-size chamber is also discussed.
Charpak, G.; Sauli, F.
This invention relates to a portable radiation monitor containing two concentric ionization chambers which permit the use of standard charging and reading devices. It is particularly adapted as a personnel x-ray dosimeter and to this end comprises a small thin walled, cylindrical conductor forming an inner energy dependent chamber, a small thin walled, cylindrical conductor forming an outer energy independent chamber, and polymeric insulation means which insulates said chambers from each other and holds the chambers together with exposed connections in a simple, trouble-free, and compact assembly substantially without variation in directional response. (AEC)
Braestrup, C.B.; Mooney, R.T.
Commissioning of SLAC SLD 45-Degree Chambers
The SLD experiment at the Stanford Linear Accelerator Center had a significant gap in its muon tracking coverage, provided by the Warm Iron Calorimeter. Supplemental planes of limited streamer tube chambers were added to improve the coverage in the vicinity of the gap at 0.65 commissioning of the forty-five degree chamber region of the SLAC SLD Warm Iron Calorimeter is presented. This task involved the completion of the forty-five degree chamber region geometry for the Warm Iron Calorimeter's fitter and swimmer and the changing of the way multiple scattering effects are treated in the fitter algorithm.
V. O. Eschenburg
R. Nygren, "The Time Projection Chamber", Physics Today, pp.out System for the Time Projection Chamber", IEEE Trans.on Nuclear Science A TIME PROJECTION CHAMBER DIGITIZER TEST
Nunnally, Curtis
Plasma Kinetic Theory
Kinetic Theory / Proceedings of the Ninth Carolus Magnus Summer School on Plasma and Fusion Energy Physics
B. Weyssow
Searches for charmed particles using bubble chambers
Searches for charm particle production using bubble chambers are summarized. These searches depend on the detection of neutral strange particles. Upper limits are given for the different charmed mass regions and methods of search. (auth)
Harris, R.
Very high intensity reaction chamber design
The problem of achieving very high intensity irradiation by light in minimal regions was studied. Three types of irradiation chamber are suggested: the common laser-reaction chamber, the folded concentric or near-concentric resonator, and the asymmetric confocal resonator. In all designs the ratio of high-intensity illuminated volume to other volume is highly dependent (to the $sup 3$/$sub 2$ power) on the power and fluence tolerances of optical elements, primarily mirrors. Optimization of energy coupling is discussed for the common cavity. For the concentric cavities, optimization for both coherent and incoherent beams is treated. Formulae and numerical examples give the size of chambers, aspect ratios, maximum pass number, image sizes, fluences, and the like. Similarly for the asymmetric confocal chamber, formulae and numerical examples for fluences, dimensions, losses, and totally contained pass numbers are given. (auth)
Devaney, J.J.
Automated Soil Gas Monitoring Chamber - Oak Ridge National ...
Automated Soil Gas Monitoring Chamber ... A chamber for trapping soil gases as they evolve from the soil without disturbance to the soil and to the natural
Chemical Kinetic Modeling of Advanced Transportation Fuels
Development of detailed chemical kinetic models for advanced petroleum-based and nonpetroleum based fuels is a difficult challenge because of the hundreds to thousands of different components in these fuels and because some of these fuels contain components that have not been considered in the past. It is important to develop detailed chemical kinetic models for these fuels since the models can be put into engine simulation codes used for optimizing engine design for maximum efficiency and minimal pollutant emissions. For example, these chemistry-enabled engine codes can be used to optimize combustion chamber shape and fuel injection timing. They also allow insight into how the composition of advanced petroleum-based and non-petroleum based fuels affect engine performance characteristics. Additionally, chemical kinetic models can be used separately to interpret important in-cylinder experimental data and gain insight into advanced engine combustion processes such as HCCI and lean burn engines. The objectives are: (1) Develop detailed chemical kinetic reaction models for components of advanced petroleum-based and non-petroleum based fuels. These fuels models include components from vegetable-oil-derived biodiesel, oil-sand derived fuel, alcohol fuels and other advanced bio-based and alternative fuels. (2) Develop detailed chemical kinetic reaction models for mixtures of non-petroleum and petroleum-based components to represent real fuels and lead to efficient reduced combustion models needed for engine modeling codes. (3) Characterize the role of fuel composition on efficiency and pollutant emissions from practical automotive engines.
PItz, W J; Westbrook, C K; Herbinet, O
The BaBar Drift Chamber
The central drift chamber for the BaBar detector at the PEP-II B-factory at SLAC is a cylindrical chamber with a length of 280 cm and outer radius of 81 cm. It consists of 40 layers of small hexagonal cells arranged in 10 axial and stereo super-layers. In order to minimize multiple scattering, light materials are used for the mechanical structure, and the gas mixture is Helium based. The pulse-height and timing electronics are mounted directly on the chamber rear end-plate. A full length prototype of the BaBar drift chamber has been built. The analysis of cosmic ray events measures the spatial resolution averaged in the cell to be 130 m and the dE/dx resolution to be 6.8%, meeting the performance goals for the BaBar central tracker. The mechanical assembly and stringing of the chamber was completed in December 1997 and the detector will be integrated into BaBar during summer 1998. 1
G. Sciolla
Computational Thermodynamics and Kinetics
Jul 31, 2011 ... About this Symposium. Meeting, 2012 TMS Annual Meeting & Exhibition. Symposium, Computational Thermodynamics and Kinetics.
Basic and Kinetic Theory / Proceedings of the Tenth Carolus Magnus Summer School on Plasma and Fusion Energy Physics
Chapter 13. Chemical Kinetics
of chemical reactions. · Only gases, for which the kinetic theory of Chapter 4 is applicable, are consideredChapter 13. Chemical Kinetics #12;· Why do some chemical reactions proceed with lighting speed when the way in which molecules combine to form products? · All of these questions involve chemical kinetics
Ihee, Hyotcherl
Kinetic Energy and the Equivalence Principle
According to the general theory of relativity, kinetic energy contributes to gravitational mass. Surprisingly, the observational evidence for this prediction does not seem to be discussed in the literature. I reanalyze existing experimental data to test the equivalence principle for the kinetic energy of atomic electrons, and show that fairly strong limits on possible violations can be obtained. I discuss the relationship of this result to the occasional claim that ``light falls with twice the acceleration of ordinary matter.''
S. Carlip
Amplifier Design for Proportional Ionization Chambers
This paper presents the requirements of a nuclear amplifier of short resolving time, designed to accept pulses of widely varying amplitudes. Data are given which show that a proportional ionization chamber loaded with a 1,000-ohm resistor develops pulses of 0.5 microsecond duration and several volts amplitude. Results indicate that seven basic requirements are imposed on the amplifier when counting soft beta and gamma radiation in the presence of alpha particles, without absorbers. It should, (1) have a fast recovery time, (2) have a relatively good low frequency response, (3) accept pulses of widely varying heights without developing spurious pulsed, (4) have a limiting output stage, (5) preserve the inherently short rise time of the chamber, (6) minimize pulse integration, and (7) have sufficient gain to detect the weak pulses well below the chamber voltage at which continuous discharge takes place. The results obtained with an amplifier which meets these requirements is described. A formula is derived which indicates that redesign of the proportional ionization chamber might eliminate the need for an amplifier. This may be possible if the radioactive particles are collimated parallel to the collecting electrode.
Baker, W. H.
Modeling and Simulation of 1025t/h CFBB Combustion Chamber
This paper takes CFBB as simulating object, which has characters of DG1025/17.4-II1 two legs furnace and with external heat exchanger. Combined with thermal process and combustion chamber working characteristics of practical unit, a general dynamic model ... Keywords: CFB, combustion, modeling, simulation
Chang-liang Liu; Yuan-liang Ma; Lin Chen
Development of bakelite based Resistive Plate Chambers
A Comparative study has been performed on Resistive Plate Chambers made of different grades of bakelite paper laminates, produced and commercially available in India. The chambers, operated in the streamer mode using argon : tetrafluroethane : isobutane in 34:59:7 mixing ratio, are tested with cosmic rays for the efficiency and the stability with cosmic rays. A particular grade of bakelite (P-120, NEMA LI-1989 Grade XXX), used for high voltage insulation in humid conditions, was found to give satisfactory performance with stable efficiency of > 96% continuously for more than 110 days. A silicone treatment of the inner surfaces of the bakelite RPC is found to be necessary for operation of the detector.
S. Biswas; S. Bhattacharya; S. Bose; S. Chattopadhyay; S. Saha; M. K. Sharan; Y. P. Viyogi
A cylindrical condensing system whose geometry allows light to be collected along the length of narrow tubular sources and to pass through a restricted port area is used. The quantity of light collected is many times that possible to obtain with axially symmetric lenses. The optical arrangement is described. Other unique features include the use of plano reilectors to extend optically the flash tube and condenser lengths and the provision of a spot plate to eliminate surface reflections from the chamber window. (auth)
Rosin, S.
A Comprehensive Investigation of Low Angle Grain Boundary Mobility in Pure Al ... A New Treatment for the Kinetics of Isothermal Oxidation of Zinc Powders.
Structure and Kinetics
Mar 4, 2013 ... Materials Science in Reduced Gravity: Structure and Kinetics ... Bias fields comprise weak interface energy sources that result from the vector�...
Vacuum chamber with a supersonic flow aerodynamic window
A supersonic flow aerodynamic window, whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.
Hanson, Clark L. (Livermore, CA)
Vacuum chamber with a supersonic-flow aerodynamic window
A supersonic flow aerodynamic window is disclosed whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.
Hanson, C.L.
Vacuum chamber for containing particle beams
A vacuum chamber for containing a charged particle beam in a rapidly changing magnetic environment comprises a ceramic pipe with conducting strips oriented along the longitudinal axis of the pipe and with circumferential conducting bands oriented perpendicular to the longitudinal axis but joined with a single longitudinal electrical connection. When both strips and bands are on the outside of the ceramic pipe, insulated from each other, a high-resistance conductive layer such as nickel can be coated on the inside of the pipe.
Harvey, A.
Sources of Eddy Kinetic Energy in the Labrador Sea
Experiments with a suite of North Atlantic general circulation models are used to examine the sources of eddy kinetic energy (EKE) in the Labrador Sea. A high-resolution model version (112�) quantitatively reproduces the observed signature. A ...
Carsten Eden; Claus B�ning
Thermodynamic and Kinetic Modeling
Oct 11, 2012... capability of the coating and thus the achievable engine efficiency. ... Aluminide coating of steels enables more efficient power generation through ... and kinetic modeling in order to build a time and temperature dependent�...
Thermodynamic & Kinetic Data for Sustainable Energy
Thermodynamic & Kinetic Data for Sustainable Energy. Summary: Industry needs thermodynamic and kinetic data for the ...
A unified moving grid gas-kinetic method in Eulerian space for viscous flow computation
Under a generalized coordinate transformation with arbitrary grid velocity, the gas-kinetic BGK equation is reformulated in a moving frame of reference. Then, a unified conservative gas-kinetic scheme is developed for the viscous flow computation in ... Keywords: 65M06, 76P05, 76T05, Gas-kinetic scheme, Moving grid, Navier-Stokes equations, Unified coordinate system
Changqiu Jin; Kun Xu
General Recycling
Indium Recovery from Discarded Light Emitting Diode (LED) Liquid Cristal Display (LCD) TVs: Influence of Leaching Reagents � Kinetic Study of Acid Copper�...
Kinetic and hydrodynamic models of chemotactic aggregation
We derive general kinetic and hydrodynamic models of chemotactic aggregation that describe certain features of the morphogenesis of biological colonies (like bacteria, amoebae, endothelial cells or social insects). Starting from a stochastic model defined in terms of N coupled Langevin equations, we derive a nonlinear mean field Fokker-Planck equation governing the evolution of the distribution function of the system in phase space. By taking the successive moments of this kinetic equation and using a local thermodynamic equilibrium condition, we derive a set of hydrodynamic equations involving a damping term. In the limit of small frictions, we obtain a hyperbolic model describing the formation of network patterns (filaments) and in the limit of strong frictions we obtain a parabolic model which is a generalization of the standard Keller-Segel model describing the formation of clusters (clumps). Our approach connects and generalizes several models introduced in the chemotactic literature. We discuss the anal...
Chavanis, Pierre-Henri
The hydrogen bubble chamber and the strange resonances
The author's recollections of his experience in the use of bubble chambers and the discoveries of strange resonances are given. (LEW)
Alvarez, L.W.
Luis Alvarez, the Hydrogen Bubble Chamber, Tritium, and Dinosaurs
Office of Scientific and Technical Information (OSTI)
Luis Alvarez, the Hydrogen Bubble Chamber, Tritium, and Dinosaurs Resources with Additional Information Patents Luis Alvarez Courtesy Lawrence Berkeley National Laboratory 'Luis...
China New Energy Chamber of Commerce CNECC | Open Energy Information
Open Energy Info (EERE)
China Zip 100052 Product A Chinese non-profit membership organization specializing in new energy industry, which is supervised by Chinese National Chamber of Commerce. References...
NIF Target Chamber Dedicated | National Nuclear Security Administratio...
National Nuclear Security Administration (NNSA)
NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > About Us > Our History > NNSA Timeline > NIF Target Chamber Dedicated NIF Target...
C. -K. Yen ENGINEERING AND INSTRUMENTATION C. Dols D. NelsonLaboratory DOSIMETRY, INSTRUMENTATION AND EXPOSURE CHAMBERSLBL-9554 DOSIMETRY, INSTRUMENTATION AND EXPOSURE CHAMBERS
Tenforde, T.S.
Dielectric liquid ionization chambers for detecting fast neutrons
Three ionization chambers with different geometries have been constructed and filled with dielectric liquids for detection of fast neutrons. The three dielectric liquids studied were Tetramethylsilane (TMS), Tetramethylpentane ...
Boyd, Erin M
Chemical kinetic modelling of hydrocarbon ignition
Chemical kinetic modeling of hydrocarbon ignition is discussed with reference to a range of experimental configurations, including shock tubes, detonations, pulse combustors, static reactors, stirred reactors and internal combustion engines. Important conditions of temperature, pressure or other factors are examined to determine the main chemical reaction sequences responsible for chain branching and ignition, and kinetic factors which can alter the rate of ignition are identified. Hydrocarbon ignition usually involves complex interactions between physical and chemical factors, and it therefore is a suitable and often productive subject for computer simulations. In most of the studies to be discussed below, the focus of the attention is placed on the chemical features of the system. The other physical parts of each application are generally included in the form of initial or boundary conditions to the chemical kinetic parts of the problem, as appropriate for each type of application being addressed.
Westbrook, C.K.; Pitz, W.J.; Curran, H.J.; Gaffuri, P.; Marinov, N.M.
Erbium hydride decomposition kinetics.
Thermal desorption spectroscopy (TDS) is used to study the decomposition kinetics of erbium hydride thin films. The TDS results presented in this report are analyzed quantitatively using Redhead's method to yield kinetic parameters (E{sub A} {approx} 54.2 kcal/mol), which are then utilized to predict hydrogen outgassing in vacuum for a variety of thermal treatments. Interestingly, it was found that the activation energy for desorption can vary by more than 7 kcal/mol (0.30 eV) for seemingly similar samples. In addition, small amounts of less-stable hydrogen were observed for all erbium dihydride films. A detailed explanation of several approaches for analyzing thermal desorption spectra to obtain kinetic information is included as an appendix.
Ferrizz, Robert Matthew
Numerical Simulation on Forced Swirl Combustion Chamber in Diesel Engine
A concept of forced swirl combustion chamber in diesel engine is proposed in this paper. It can be used to enhance the intensity of swirl flow in the cylinder and accelerate the rate of air-fuel mixture process by designing the special structure in the ... Keywords: diesel engine, forced swirl, combustion chamber, simulation
Shang Yong; Liu Fu-shui; Li Xiang-rong
Yong Shang; Fu-shui Liu; Xiang-rong Li
Jet engine's speed controller with constant pressure chamber
The paper deals with an automatic system meant to control a jet engine's rotation speed, through the fuel injection's control, based on a constant pressure chamber controller. One has established the non-linear mathematical model (based on the motion ... Keywords: actuator, control, fuel injection, fuel pump, jet-engine, pressure chamber
Alexandru Nicolae Tudosie
NIF Target Chamber Dedicated | National Nuclear Security Administration
NIF Target Chamber Dedicated | National Nuclear Security Administration NIF Target Chamber Dedicated | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > About Us > Our History > NNSA Timeline > NIF Target Chamber Dedicated NIF Target Chamber Dedicated June 11, 1999 Livermore, CA NIF Target Chamber Dedicated Secretary Richardson dedicates the National Ignition Facility target
Improving the performance and fuel consumption of dual chamber stratified charge spark ignition engines
A combined experimental and theoretical investigation of the nature of the combustion processes in a dual chamber stratified charge spark ignition engine is described. This work concentrated on understanding the mixing process in the main chamber gases. A specially constructed single cylinder engine was used to both conduct experiments to study mixing effects and to obtain experimental data for the validation of the computer model which was constructed in the theoretical portion of the study. The test procedures are described. Studies were conducted on the effect of fuel injection timing on performance and emissions using the combination of orifice size and prechamber to main chamber flow rate ratio which gave the best overall compromise between emissions and performance. In general, fuel injection gave slightly higher oxides of nitrogen, but considerably lower hydrocarbon and carbon monoxide emissions than the carbureted form of the engine. Experiments with engine intake port redesign to promote swirl mixing indicated a substantial increase in the power output from the engine and, that an equivalent power levels, the nitric oxide emissions are approximately 30% lower with swirl in the main chamber than without swirl. The development of a computer simulation of the combustion process showed that a one-dimensional combustion model can be used to accurately predict trends in engine operation conditions and nitric oxide emissions even though the actual flame in the engine is not completely one-dimensional, and that a simple model for mixing of the main chamber and prechamber intake gases at the start of compression proved adequate to explain the effects of swirl, ignition timing, overall fuel air ratio, volumetric efficiency, and variations in prechamber air fuel ratio and fuel rate percentage on engine power and nitric oxide emissions. (LCL)
Sorenson, S.C.; Pan, S.S.; Bruckbauer, J.J.; Gehrke, G.R.
Chemistry of radiation damage to wire chambers
Proportional counters are used to study aspects of radiation damage to wire chambers (wire aging). Principles of low-pressure, rf plasma chemistry are used to predict the plasma chemistry in electron avalanches (1 atm, dc). (1) Aging is studied in CF{sub 4}/iC{sub 4}H{sub 10} gas mixtures. Wire deposits are analyzed by Auger electron spectroscopy. An apparent cathode aging process resulting in loss of gain rather than in a self-sustained current is observed in CF{sub 4}-rich gases. A four-part model considering plasma polymerization of the hydrocarbon, etching of wire deposits by CF{sub 4}, acceleration of deposition processes in strongly etching environments, and reactivity of the wire surface is developed to understand anode wire aging in CF{sub 4}/iC{sub 4}H{sub 10} gases. Practical guidelines suggested by the model are discussed. (2) Data are presented to suggest that trace amounts of Freons do not affect aging rates in either dimethyl ether or Ar/C{sub 2}H{sub 6}. Apparent loss of gain is explained by attachment of primary electrons to a continuously increasing concentration of Freon 11 (CCl{sub 3}F) in the counter gas. An increase in the concentration of Freon 11 in dimethyl ether is caused by a distillation process in the gas supply bottle and is a natural consequence of the unequal volatilities of the two compounds.
Chemical kinetics models for semiconductor processing
Chemical reactions in the gas-phase and on surfaces are important in the deposition and etching of materials for microelectronic applications. A general software framework for describing homogeneous and heterogeneous reaction kinetics utilizing the Chemkin suite of codes is presented. Experimental, theoretical and modeling approaches to developing chemical reaction mechanisms are discussed. A number of TCAD application modules for simulating the chemically reacting flow in deposition and etching reactors have been developed and are also described.
Coltrin, M.E.; Creighton, J.R. [Sandia National Labs., Albuquerque, NM (United States); Meeks, E.; Grcar, J.F.; Houf, W.G. [Sandia National Labs., Livermore, CA (United States); Kee, R.J. [Colorado School of Mines, Golden, CO (United States)
LLNL Chemical Kinetics Modeling Group
The LLNL chemical kinetics modeling group has been responsible for much progress in the development of chemical kinetic models for practical fuels. The group began its work in the early 1970s, developing chemical kinetic models for methane, ethane, ethanol and halogenated inhibitors. Most recently, it has been developing chemical kinetic models for large n-alkanes, cycloalkanes, hexenes, and large methyl esters. These component models are needed to represent gasoline, diesel, jet, and oil-sand-derived fuels.
Pitz, W J; Westbrook, C K; Mehl, M; Herbinet, O; Curran, H J; Silke, E J
Kinetic Theory of Plasma Waves
Kinetic Wave Theory / Proceedings of the Tenth Carolus Magnus Summer School on Plasma and Fusion Energy Physics
D. Van Eester; E. Lerche
An Application of Chemical Kinetic Theory and Methodology to Characterize the Ice Nucleating Properties of Aerosols Used for Weather Modification
Chemical kinetic theory and methodology is applied to examine the ice nucleating properties of silver iodide (AgI) and silver iodide-silver chloride (AgI-AgCl) aerosols in a large cloud chamber held at water saturation. This approach uses ...
Paul J. DeMott; William G. Finnegan; Lewis O. Grant
Kinetic effects on ballooning modes in mirror machines
A general procedure for examining the influence of kinetic effects on the stability of magnetohydrodynamic ballooning modes in mirror machines is presented. In particular, the basic kinetic ballooning mode equation for a nonaxisymmetric, arbitrary beta system with anisotropic pressure is derived. Considering a long-thin equilibrium typical of the tandem mirror, it is shown that this governing eigenmode equation reduces to a simple form independent of wave-particle resonant effects.
Tang, W.M.; Catto, P.J.
Reaction kinetics for remodeling oil shale retorting
Results from recent laboratory kinetic studies at the Lawrence Livermore Laboratory (LLL) on gasification, pyrolysis, and mineral reactions in oil shale are presented. The specific pyrolysis reactions investigated include the decomposition of kerogen, the evolution of oil, hydrogen and C/sub 2/ plus C/sub 3/ hydrocarbons and the formation of a carbonaceous residue. Data describing the evolution of H/sub 2/ and CH/sub 4/ during secondary pyrolysis of the carbonaceous residue are also presented. The mineral reaction kinetics discussed include the decomposition and/or reaction (with silica or silicates) of calcite, dolomite, dawsonite and nahcolite. Rate equations describing the effects of CO/sub 2/ and steam on the reactions of calcite and dolomite are presented. Finally, kinetics describing gasification of the carbonaceous residue by CO/sub 2/ and H/sub 2/O are examined. The above kinetic data are summarized in a set of rate expressions that can be used in numerical modeling of oil shale retorting. The rate equations are general enough for modeling both in-situ and surface retorting processes.
Campbell, J.H.; Burnham, A.K.
General Information
Environment Feature Stories Public Reading Room: Environmental Documents, Reports LANL Home Phonebook Calendar Video Business Small Business General Information General...
BSA 08-14: A Multi-Anode Ionization Chamber
BSA 08-14: A Multi-Anode Ionization Chamber. BNL Reference Number: BSA 08-14. Patent Status: U.S. Patent Number 7,858,949 was issued on December 28, 2010
Single chamber fuel cells: Flow geometry, rate and composition considerations
the key technical hurdles in SOFC development. Furthermore,bellow those of dual chamber SOFC, and increase even moresmaller than that of other SOFC, but the heat generated by
Stefan, Ionel C.; Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.
Modeling chamber transport for heavy-ion fusion
representation of the molten-salt jets. Acknowledgments Thisto the target. Since molten-salt jets are planned to protectshielding, two meters of molten-salt jets inside the chamber
A New Horizontal Gradient, Continuous Flow, Ice Thermal Diffusion Chamber
A continuous-flow, horizontal gradient, ice thermal diffusion chamber has been developed and tested for heterogeneous ice nucleation of aerosol particles under accurately controlled supersaturations and supercooling in the absence of a substrate. ...
E. M. Tomlinson; N. Fukuta
temperature environmental chamber. The tests were all run at 25 C, 50% relative humidity (RH) and with an area-specific ventilation rate of 1.5 cubic meters per square meter...
A self-triggered readout for a time projection chamber
A self-triggering readout for a time projection chamber (TPC) is presented, with applications to novel forms of data acquisition for high energy physics application. The construction and initial testing of the readout ...
Werner, Andrew Thompson, 1981-
How to Build a Cosmic-Ray Cloud Chamber How to Build a Cosmic-Ray Cloud Chamber October 2008, Version 1.4 * QuarkNet version. Fermi National Accelerator Laboratory. * Instructions written by Jeremy Paschke, York High School and Anne Mary Teichert, Fermilab. * Model initially designed and built by Robert Peterson, Fermilab. If you have further questions, or improvements of your own you would like to share with the QuarkNet group, please contact: Jeremy Paschke, York High School Physics Instructor (email@example.com), or Bob Peterson, Fermilab Education Specialist, (firstname.lastname@example.com). Justification: Showing your class a working cloud chamber is one of the best ways to generate student interest in modern physics. The cloud chamber described below will display natural background radiation (muons generated by
Aging in the large CDF axial drift chamber
The Central Outer Tracker (COT) is a large axial drift chamber in the Collider Detector at Fermilab operating with a gas mixture that is 50/50 argon/ethane with an admixture of 1.7% isopropanol. In its first two years of operation the COT showed unexpected aging with the worst parts of the chamber experiencing a gain loss of {approx}50% for an accumulated charge of {approx}35 mC/cm. By monitoring the pulse height of hits on good tracks, it was possible to determine the gain as a function of time and location in the chamber. In addition, the currents of the high voltage supplies gave another monitor of chamber gain and its dependence on the charge deposition rate. The aging was worse on the exhaust end of the chamber consistent with polymer buildup as the gas flows through the chamber. The distribution in azimuth suggests that aging is enhanced at lower temperatures, but other factors such as gas flow patterns may be involved. Elemental and molecular analysis of the sense wires found a coating that is mostly carbon and hydrogen with a small amount of oxygen; no silicon or other contaminants were identified. High resolution electron microscope pictures of the wire surface show that the coating is smooth with small sub-micron nodules. In the course of working with the chamber gas system, we discovered a small amount of O{sub 2} is enough to reverse the aging. Operating the chamber with {approx}100 ppm of O{sub 2} reversed almost two years of gain loss in less than 10 days while accumulating {le} 2 mC/cm.
Allspach, D.; Ambrose, D.; Binkley, M.; /Fermilab; Bromberg, C.; /Michigan State U.; Burkett, K.; Kephart, R.; Madrak, R.; Miao, T.; Mukherjee, A.; Roser, R.; Wagner, R.L. /Fermilab
Broadband impedance calculations of the TAN vacuum chamber for the Large Hadron Collider (LHC)
CHAMBER FOR THE LARGE HADRON COLLIDER (LHC) ? D. Li � , G.chamber for the Large Hadron Collider (LHC). The TAN is the
Li, D.; Lambertson, G.; Turner, W.
Dark matter limits froma 15 kg windowless bubble chamber
The COUPP collaboration has successfully used bubble chambers, a technology previously applied only to high-energy physics experiments, as direct dark matter detectors. It has produced the world's most stringent spin-dependent WIMP limits, and increasingly competitive spin-independent limits. These limits were achieved by capitalizing on an intrinsic rejection of the gamma background that all other direct detection experiments must address through high-density shielding and empirically-determined data cuts. The history of COUPP, including its earliest prototypes and latest results, is briefly discussed in this thesis. The feasibility of a new, windowless bubble chamber concept simpler and more inexpensive in design is discussed here as well. The dark matter limits achieved with a 15 kg windowless chamber, larger than any previous COUPP chamber (2 kg, 4 kg), are presented. Evidence of the greater radiopurity of synthetic quartz compared to natural is presented using the data from this 15 kg device, the first chamber to be made from synthetic quartz. The effective reconstruction of the three-dimensional positions of bubbles in a highly distorted optical field, with ninety-degree bottom lighting similar to cloud chamber lighting, is demonstrated. Another innovation described in this thesis is the use of the sound produced by bubbles recorded by an array of piezoelectric sensors as the primary means of bubble detection. In other COUPP chambers, cameras have been used as the primary trigger. Previous work on bubble acoustic signature differentiation using piezos is built upon in order to further demonstrate the ability to discriminate between alpha- and neutron-induced events.
Szydagis, Matthew Mark; /Chicago U.
Kinetics of coal pyrolysis
This report contains results of a coordinated, multi-laboratory investigation of coal devolatilization. Data is reported pertaining to the devolatilization for bituminous coals over three orders of magnitude in apparent heating rate (100 to 100,000 + {degree}C/sec), over two orders of magnitude in particle size (20 to 700 microns), final particle temperatures from 400 to 1600{degree}C, heat transfer modes ranging from convection to radiative, ambient pressure ranging from near vacuum to one atmosphere pressure. The heat transfer characteristics of the reactors are reported in detail. It is assumed the experimental results are to form the basis of a devolatilization data base. Empirical rate expressions are developed for each phase of devolatilization which, when coupled to an awareness of the heat transfer rate potential of a particular devolatilization reactor, indicate the kinetics emphasized by a particular system reactor plus coal sample. The analysis indicates the particular phase of devolatilization that will be emphasized by a particular reactor type and, thereby, the kinetic expressions appropriate to that devolatilization system. Engineering rate expressions are developed from the empirical rate expressions in the context of a fundamental understanding of coal devolatilization developed in the course of the investigation. 164 refs., 223 figs., 44 tabs.
Seery, D.J.; Freihaut, J.D.; Proscia, W.M. (United Technologies Research Center, East Hartford, CT (USA)); Howard, J.B.; Peters, W.; Hsu, J.; Hajaligol, M.; Sarofim, A. (Massachusetts Inst. of Tech., Cambridge, MA (USA)); Jenkins, R.; Mallin, J.; Espindola-Merin, B. (Pennsylvania State Univ., University Park, PA (USA)); Essenhigh, R.; Misra, M.K. (Ohio State Univ., Columbus, OH (USA))
Amber Kinetics | Open Energy Information
search Name Amber Kinetics Product Start-up company developing a novel flywheel energy storage system with the Lawrence Livermore National Laboratory. References Amber...
Development of Novel Density Functionals for Thermochemical Kinetics
A new density functional theory (DFT) exchange-correlation functional for the exploration of reaction mechanisms is proposed. This new functional, denoted BMK (Boese-Martin for Kinetics), has an accuracy in the 2 kcal/mol range for transition state barriers but, unlike previous attempts at such a functional, this improved accuracy does not come at the expense of equilibrium properties. This makes it a general-purpose functional whose domain of applicability has been extended to transition states, rather than a specialized functional for kinetics. The improvement in BMK rests on the inclusion of the kinetic energy density together with a large value of the exact exchange mixing coefficient. For this functional, the kinetic energy density appears to correct `back' the excess exact exchange mixing for ground-state properties, possibly simulating variable exchange.
Boese, A D; Martin, Jan M. L.
Method to calibrate fission chambers in Campbelling mode
Fission chambers are neutron detectors which are widely used to instrument experimental reactors such as material testing reactors or zero power reactors. In the presence of a high level mixed gamma and neutron flux, fission chambers can be operated in Campbelling mode (also known as 'fluctuation mode' or 'mean square voltage mode') to provide reliable and precise neutron related measurements. Fission chamber calibration in Campbelling mode (in terms of neutron flux) is usually done empirically using a calibrated reference detector. A major drawback of this method is that calibration measurements have to be performed in a neutron environment very similar to the one in which the calibrated detector will be used afterwards. What we propose here is a different approach based on characterizing the fission chamber response in terms of fission rate. This way, the detector calibration coefficient is independent from the neutron spectrum and can be determined prior to the experiment. The fissile deposit response to the neutron spectrum can then be assessed independently by other means (experimental or numerical). In this paper, the response of CEA made miniature fission chambers in Campbelling mode is studied. We use a theoretical model of the signal to calculate the calibration coefficient. Input parameters of the model come from statistical distribution of individual pulses. Supporting measurements have been made in the CEA Cadarache zero power reactor MINERVE. Results are compared to an empirical Campbelling mode calibration.
Benoit Geslot; Troy C. Unruh; Philippe Filliatre; Christian Jammes; Jacques Di Salvo; St�phane Br�aud; Jean-Fran�ois Villard
Investigation of Argon Gas as a Potential Shock Attenuator in Z-IFE Chambers Using ALEGRA
Technical Paper / The Technology of Fusion Energy - Inertial Fusion Technology: Targets and Chambers
Sal B. Rodriguez; Jason Cook
A Continuous, In-Chamber Target Tracking and Engagement Approach for Laser Fusion
Ron Petzoldt; Neil Alexander; Lane Carlson; Graham Flint; Dan Goodin; Jon Spalding; Mark Tillack
Challenge Met as APS Sends Final Chambers to LCLS
A Marriage of Hardware and Hard Work A Marriage of Hardware and Hard Work Shaken but Not Stirred 2008 Rosalind Franklin Young Investigator Award The 2008 3-Way Meeting In R&D, Super X-rays Mark Many Spots APS News Archives: 2012 | 2011 | 2010 | 2009 2008 | 2007 | 2006 | 2005 2004 | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed Challenge Met as APS Sends Final Chambers to LCLS MAY 21, 2008 Bookmark and Share The final five (of 40) extruded aluminum vacuum chambers for the Linac Coherent Light Source (LCLS) undulator system have been shipped from Argonne National Laboratory - where the chambers were designed and assembled - to the Stanford Linear Accelerator Center, where the LCLS "will be the world's first x-ray free electron laser when it becomes operational in 2009. Pulses of x-ray laser light from LCLS will be many
Chamber Design for the Laser Inertial Fusion Energy (LIFE) Engine
The Laser Inertial Fusion Energy (LIFE) concept is being designed to operate as either a pure fusion or hybrid fusion-fission system. The present work focuses on the pure fusion option. A key component of a LIFE engine is the fusion chamber subsystem. It must absorb the fusion energy, produce fusion fuel to replace that burned in previous targets, and enable both target and laser beam transport to the ignition point. The chamber system also must mitigate target emissions, including ions, x-rays and neutrons and reset itself to enable operation at 10-15 Hz. Finally, the chamber must offer a high level of availability, which implies both a reasonable lifetime and the ability to rapidly replace damaged components. An integrated design that meets all of these requirements is described herein.
Latkowski, J F; Abbott, R P; Aceves, S; Anklam, T; Badders, D; Cook, A W; DeMuth, J; Divol, L; El-Dasher, B; Farmer, J C; Flowers, D; Fratoni, M; ONeil, R G; Heltemes, T; Kane, J; Kramer, K J; Kramer, R; Lafuente, A; Loosmore, G A; Morris, K R; Moses, G A; Olson, B; Pantano, C; Reyes, S; Rhodes, M; Roe, K; Sawicki, R; Scott, H; Spaeth, M; Tabak, M; Wilks, S
Electromagnetic pulse generation within a petawatt laser target chamber
Recent work has been undertaken to characterize the electromagnatic pulse (EMP) generated by the high temperature high density plasma produced by a petawatt laser. This was to evaluate the susceptibility to malfunction and damage of equipment and diagnostics for the new Orion laser. EMP measurement were made using moebius loop antennas fitted inside the target chamber of the Vulcan petawatt laser at the Rutherford Appleton Laboratory. These show the EMP as a 63 MHz transient which decays from a peak magnetic field of around 4.3 A/m. A theoretical model presented assumes the EMP is produced by an impulse of 10{sup 12} electron emanating from the target, which charge the chamber wall causing it to ring at natural frequency. The theoretical model provides an estimate of the EMP measured in the Vulcan petawatt target chamber and will be used for the design of the Orion laser.
Mead, M.J.; Neely, D.; Gauoin, J.; Heathcote, R.; Patel, P. [Atomic Weapons Establishment, Aldermaston, Reading, RG7 4PR (United Kingdom); CLRC Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX (United Kingdom); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
Federation of Indian Chambers of Commerce & Industry (FICCI) | Department
Energy.gov (U.S. Department of Energy (DOE)) Indexed Site
Federation of Indian Chambers of Commerce & Industry (FICCI) Federation of Indian Chambers of Commerce & Industry (FICCI) Federation of Indian Chambers of Commerce & Industry (FICCI) March 20, 2007 - 11:37am Addthis Thank you Geoff (Pyatt) for that introduction. I'd like to thank FICCI for hosting this event and thank its leadership for their kind words. I'm very pleased to be here in India - and to be with all of you today. Since his very first days in office, President Bush has considered growing and strengthening the United States' bilateral relationship with India to be a top priority. The shared commitment of President Bush and Prime Minister Singh to building our relationship was evidenced by the historic strategic partnership initiatives announced during the President's visit here in March of last year.
5, 86898714, 2005 The Kinetic
Technical Note: Simulating chemical systems in Fortran90 and Matlab with the Kinetic PreProcessor KPP-2.1 A estimation techniques, and variational chemical data assimilation applications require the development of ef- ficient tools for the computational simulation of chemical kinetics systems. From a numerical point
Paris-Sud XI, Université de
Inertial range turbulence in kinetic plasmas
The transfer of turbulent energy through an inertial range from the driving scale to dissipative scales in a kinetic plasma followed by the conversion of this energy into heat is a fundamental plasma physics process. A theoretical foundation for the study of this process is constructed, but the details of the kinetic cascade are not well understood. Several important properties are identified: (a) the conservation of a generalized energy by the cascade; (b) the need for collisions to increase entropy and realize irreversible plasma heating; and (c) the key role played by the entropy cascade--a dual cascade of energy to small scales in both physical and velocity space--to convert ultimately the turbulent energy into heat. A strategy for nonlinear numerical simulations of kinetic turbulence is outlined. Initial numerical results are consistent with the operation of the entropy cascade. Inertial range turbulence arises in a broad range of space and astrophysical plasmas and may play an important role in the ther...
Howes, G G
The transfer of turbulent energy through an inertial range from the driving scale to dissipative scales in a kinetic plasma followed by the conversion of this energy into heat is a fundamental plasma physics process. A theoretical foundation for the study of this process is constructed, but the details of the kinetic cascade are not well understood. Several important properties are identified: (a) the conservation of a generalized energy by the cascade; (b) the need for collisions to increase entropy and realize irreversible plasma heating; and (c) the key role played by the entropy cascade--a dual cascade of energy to small scales in both physical and velocity space--to convert ultimately the turbulent energy into heat. A strategy for nonlinear numerical simulations of kinetic turbulence is outlined. Initial numerical results are consistent with the operation of the entropy cascade. Inertial range turbulence arises in a broad range of space and astrophysical plasmas and may play an important role in the thermalization of fusion energy in burning plasmas.
G. G. Howes
Fuel subassembly leak test chamber for a nuclear reactor
A container with a valve at one end is inserted into a nuclear reactor coolant pool. Once in the pool, the valve is opened by a mechanical linkage. An individual fuel subassembly is lifted into the container by a gripper; the valve is then closed providing an isolated chamber for the subassembly. A vacuum is drawn on the chamber to encourage gaseous fission product leakage through any defects in the cladding of the fuel rods comprising the subassembly; this leakage may be detected by instrumentation, and the need for replacement of the assembly ascertained.
Divona, Charles J. (Santa Ana, CA)
Four different single chamber fuel cell designs were compared using propane-air gas mixtures. Gas flow around the electrodes has a significant influence on the open circuit voltage and the power density of the cell. The strong influence of flow geometry is likely due to its effect on gas composition, particularly on the oxygen chemical potential at the two electrodes as a result of gas mixing. The chamber design which exposes the cathode first to the inlet gas was found to yield the best performance at lower flow rates, while the open tube design with the electrodes equally exposed to the inlet gas worked best at higher flow rates.
The Laser Calibration System of the ALICE Time Projection Chamber
Collider (LHC) dedicated to the study of heavy ion collisions. The Time Projection Chamber (TPC) is the main tracking detector covering the pseudo rapidity range |? | laser system is to simulate ionizing tracks at predifined positions throughout the drift volume in order to monitor the TPC response to a known source. In particular, the alignment of the read-out chambers will be performed, and variations of the drift velocity due to drift field imperfections can be measured and used as calibration data in the physics data analysis. In this paper we present the design of the pulsed UV laser and optical system, together with the control and monitoring systems.
G. Renault; B. S. Nielsen; J. Westergaard; J. J. Gaardh�je For The
April 10, 2002 A. R. Raffray, et al., Dynamic Chamber Armor Behavior in IFE and MFE 1 Dynamic Chamber Armor Behavior in IFE and MFE
April 10, 2002 A. R. Raffray, et al., Dynamic Chamber Armor Behavior in IFE and MFE 1 Dynamic Chamber Armor Behavior in IFE and MFE A. R. Raffray1, G. Federici2, A. Hassanein3, D. Haynes4 1University Diego April 10, 2002 #12;April 10, 2002 A. R. Raffray, et al., Dynamic Chamber Armor Behavior in IFE
Raffray, A. René
Di usive Kinetic Explicit Schemes for Nonlinear Degenerate Parabolic Systems
Di#11;usive Kinetic Explicit Schemes for Nonlinear Degenerate Parabolic Systems #3; D. Aregba parabolic systems. These schemes are based on discrete BGK models where both characteristic velocities. Evje and K.H. Karlsen [15] and of M. Espedal and K.H. Karlsen [14]. For the theory of general parabolic
Right/left assignment in drift chambers and proportional multiwire chambers (PWC's) using induced signals
Improved multiwire chamber having means for resolving the left/right ambiguity in the location of an ionizing event. The chamber includes a plurality of spaced parallel anode wires positioned between spaced planar cathodes. Associated with each of the anode wires are a pair of localizing wires, one positioned on either side of the anode wire. The localizing wires are connected to a differential amplifier whose output polarity is determined by whether the ionizing event occurs to the right or left of the anode wire.
Walenta, Albert H. (Upton, NY)
Computation of azimuthal combustion instabilities in an helicopter combustion chamber
Computation of azimuthal combustion instabilities in an helicopter combustion chamber C. Sensiau to compute azimuthal combustion instabilities is presented. It requires a thermoacoustic model using a n - formulation for the coupling between acoutics and combustion. The parameters n and are computed from a LES
Nicoud, Franck
Modeling Chamber Transport for Heavy-Ion Fusion
In a typical thick-liquid-wall scenario for heavy-ion fusion (HIF), between seventy and two hundred high-current beams enter the target chamber through ports and propagate about three meters to the target. Since molten-salt jets are planned to protect the chamber wall, the beams move through vapor from the jets, and collisions between beam ions and this background gas both strip the ions and ionize the gas molecules. Radiation from the preheated target causes further beam stripping and gas ionization. Due to this stripping, beams for heavy-ion fusion are expected to require substantial neutralization in a target chamber. Much recent research has, therefore, focused on beam neutralization by electron sources that were neglected in earlier simulations, including emission from walls and the target, photoionization by the target radiation, and pre-neutralization by a plasma generated along the beam path. When these effects are included in simulations with practicable beam and chamber parameters, the resulting focal spot is approximately the size required by a distributed radiator target.
Sharp, W M; Niller, D A C; Tabak, M; Yu, S S; Peterson, P F; Welch, D R; Rose, D V; Olson, C L
ARIES INERTIAL FUSION CHAMBER ASSESSMENT M. S. Tillack, F. Najmabadi
Washington, DC 20375 L. M. Waganer Boeing Company P.O. Box 516 St Louis, MO 63166-0516 and the ARIES Team to define design windows and explore in detail the tradeoffs for various chamber concepts. The work to better understand fundamental tradeoffs, characterize design windows and offer additional guidance to R
California at San Diego, University of
Thermodynamics and Kinetics Information at NIST
... Staff (06/28/2013). Thermodynamic & Kinetic Data for Sustainable Energy (10/05/2012). Thermodynamics and Kinetics Group (07/06/2013 ...
Modification of {Delta}{sup Prime} by magnetic feedback and kinetic effects
Two possible ways of modifying the linear tearing mode index, by active magnetic feedback and by drift kinetic effects of deeply trapped particles, are analytically investigated. Magnetic feedback schemes, studied in this work, are found generally stabilizing for {Delta}{sup Prime }. The drift kinetic effects from both thermal particles and hot ions tend to reduce the power of the large solution from the outer region. This generally leads to a destabilization of {Delta} Prime for the toroidal analytic equilibria considered here.
Liu Yueqiang; Hastie, R. J.; Hender, T. C. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)
Metal reduction kinetics in Shewanella
Motivation: Metal reduction kinetics have been studied in cultures of dissimilatory metal reducing bacteria which include the Shewanella oneidensis strain MR-1. Estimation of system parameters from time-series data faces obstructions in ...
Raman Lall; Julie Mitchell
Theoretical Studies in Chemical Kinetics
Theoretical Studies in Chemical Kinetics ^ ^ iCi| Theoretical Studies in Chemical Kinetics ^ ^ iCi| under AEC Contract A T (30-1)-3780 " ■ ' Annual Report (1970) Principal In-vestigator: Martin Karpins Institution: Harvard University The research performed under this contract can best be sunmarized under several headings. (a) Alkali-Halideg Alkali-Halide (MX^ M*X*) Exchange Reactions. This project is being continued. A careful study of certain
Combustion in Homogeneous Charge Compression Ignition Engines: Experiments and Detailed Chemical Kinetic Simulations
Homogeneous charge compression ignition (HCCI) engines are being considered as an alternative to diesel engines. The HCCI concept involves premixing fuel and air prior to induction into the cylinder (as is done in current spark-ignition engine) then igniting the fuel-air mixture through the compression process (as is done in current diesel engines). The combustion occurring in an HCCI engine is fundamentally different from a spark-ignition or Diesel engine in that the heat release occurs as a global autoignition process, as opposed to the turbulent flame propagation or mixing controlled combustion used in current engines. The advantage of this global autoignition is that the temperatures within the cylinder are uniformly low, yielding very low emissions of oxides of nitrogen (NO{sub x}, the chief precursors to photochemical smog). The inherent features of HCCI combustion allows for design of engines with efficiency comparable to, or potentially higher than, diesel engines. While HCCI engines have great potential, several technical barriers exist which currently prevent widespread commercialization of this technology. The most significant challenge is that the combustion timing cannot be controlled by typical in-cylinder means. Means of controlling combustion have been demonstrated, but a robust control methodology that is applicable to the entire range of operation has yet to be developed. This research focuses on understanding basic characteristics of controlling and operating HCCI engines. Experiments and detailed chemical kinetic simulations have been applied to the characterize some of the fundamental operational and design characteristics of HCCI engines. Experiments have been conducted on single and multi-cylinder engines to investigate general features of how combustion timing affects the performance and emissions of HCCI engines. Single-zone modeling has been used to characterize and compare the implementation of different control strategies. Multi-zone modeling has been applied to investigate combustion chamber design with respect to increasing efficiency and reducing emissions in HCCI engines.
Flowers, D L
General Engineers
U.S. Energy Information Administration (EIA) Indexed Site
General Engineers General Engineers The U.S. Energy Information Administration (EIA) within the Department of Energy has forged a world-class information program that stresses quality, teamwork, and employee growth. In support of our program, we offer a variety of profes- sional positions, including the General Engineer, whose work is associated with analytical studies and evaluation projects pertaining to the operations of the energy industry. Responsibilities: General Engineers perform or participate in one or more of the following important functions: * Design modeling systems to represent energy markets and the physical properties of energy industries * Conceive, initiate, monitor and/or conduct planning and evaluation projects and studies of continuing and future
Investigation of Micro Porosity Sintered wick in Vapor Chamber for Fan Less Design
Micro Porosity Sintered wick is made from metal injection molding processes, which provides a wick density with micro scale. It can keep more than 53 % working fluid inside the wick structure, and presents good pumping ability on working fluid transmission by fine infiltrated effect. Capillary pumping ability is the important factor in heat pipe design, and those general applications on wick structure are manufactured with groove type or screen type. Gravity affects capillary of these two types more than a sintered wick structure does, and mass heat transfer through vaporized working fluid determines the thermal performance of a vapor chamber. First of all, high density of porous wick supports high transmission ability of working fluid. The wick porosity is sintered in micro scale, which limits the bubble size while working fluid vaporizing on vapor section. Maximum heat transfer capacity increases dramatically as thermal resistance of wick decreases. This study on permeability design of wick structure is 0.5 - 0.7, especially permeability (R) = 0.5 can have the best performance, and its heat conductivity is 20 times to a heat pipe with diameter (Phi) = 10mm. Test data of this vapor chamber shows thermal performance increases over 33 %.
C. S. Yu; W. C. Wei; S. W. Kang
Combustion chamber and thermal vapor stream producing apparatus and method
A new and improved method and apparatus for burning a hydrocarbon fuel for producing a high pressure thermal vapor stream comprising steam and combustion gases for injecting into a subterranean formation for the recovery of liquefiable minerals therefrom, wherein a high pressure combustion chamber having multiple refractory lined combustion zones of varying diameters is provided for burning a hydrocarbon fuel and pressurized air in predetermined ratios injected into the chamber for producing hot combustion gases essentially free of oxidizing components and solid carbonaceous particles. The combustion zones are formed by zones of increasing diameters up a final zone of decreasing diameter to provide expansion zones which cause turbulence through controlled thorough mixing of the air and fuel to facilitate complete combustion. The high pressure air and fuel is injected into the first of the multiple zones where ignition occurs with a portion of the air injected at or near the point of ignition to further provide turbulence and more complete combustion.
Sperry, John S. (Houston, TX); Krajicek, Richard W. (Sugar Land, TX); Cradeur, Robert R. (Spring, TX)
Destruction of nuclear graphite using closed chamber incineration
Closed chamber incineration (CCI) is a novel technique by which irradiated nuclear graphite may be destroyed without the risk of radioactive cation release into the environment. The process utilizes an enclosed combustion chamber coupled with molten carbonate fuel cells (MCFCs). The transport of cations is intrinsically suppressed by the MCFCs, such that only the combustion gases are conducted through for release to the environment. An example CCI design was developed which had as its goal the destruction of graphite fuel elements from the Fort St. Vrain reactor (FSVR). By employing CCI, the volume of high level waste from the FSVR will be reduced by approximately 87 percent. Additionally, the incineration process will convert the SiC coating on the FSVR fuel particles to SiO{sub 2}, thus creating a form potentially suitable for direct incorporation in a vitrification process stream. The design is compact, efficient, and makes use of currently available technology.
Senor, D.J.; Hollenberg, G.W.; Morgan, W.C. [Pacific Northwest Lab., Richland, WA (United States); Marianowski, L.G. [Institute of Gas Technology, Chicago, IL (United States)
Study of the response of low pressure ionization chambers
The Beam Loss Monitoring System (BLM) of the Large Hadron Collider (LHC) is based on parallel plate Ionization Chambers (IC) with active volume 1.5l and a nitrogen filling gas at 0.1 bar overpressure. At the largest loss locations, the ICs generate signals large enough to saturate the read-out electronics. A reduction of the active volume and filling pressure in the ICs would decrease the amount of charge collected in the electrodes, and so provide a higher saturation limit using the same electronics. This makes Little Ionization Chambers (LIC) with both reduced pressure and small active volume a good candidate for these high radiation areas. In this contribution we present measurements performed with several LIC monitors with reduced active volume and various filling pressures. These detectors were tested under various conditions with different beam setups, with standard LHC ICs used for calibration purposes
Nebot Del Busto, E; Effinger, E; Grishin, V; Herranz Alvarez, J
Tobacco smoke aging in the presence of ozone: a room-sized chamber...
Tobacco smoke aging in the presence of ozone: a room-sized chamber study Title Tobacco smoke aging in the presence of ozone: a room-sized chamber study Publication Type Journal...
A Continuous-Flow Diffusion Chamber for Airborne Measurements of Ice Nuclei
A continuous-flow thermal gradient diffusion chamber was developed for operating in an aircraft and detecting ice nucleating aerosol particles in real time. The chamber volume is the annular space between two vertically oriented concentric ...
David C. Rogers; Paul J. DeMott; Sonia M. Kreidenweis; Yalei Chen
Aging Chamber Report Tool (ACRT) Version 5.0
The 230kV Accelerated Aging Chamber is a multi-year test of more than 50 polymer and fiberglass components.� Photographic inspections occur twice a year.� Thousands of photographs accumulate making conventional reports difficult to read.� This reporting tool enables the reader to jump from component to component and inspection to inspection.� The reader can easily compare components at different levels of aging.� This tool will make reviewing the important results of this ...
Aging Chamber Report Tool (ACRT) v6.0
High Rate Resistive Plate Chamber for LHC detector upgrades
The limitation of the detection rate of standard bakelite resistive plate chambers (RPC) used as muon detectors in the LHC experiments has prevented the use of such detectors in the high rate regions in both CMS and ATLAS detectors. One alternative to these detectors are RPCs made with low resistivity glass plates ($10^{10} {\\rm \\Omega .cm}$), a beam test at DESY has shown that such detectors can operate at few thousand Hz/cm$^2$ with high efficiency(> 90%)
Y. Haddad; G. Grenier; I. Laktineh; N. Lumb; S. Cauwenbergh
Using sputter coated glass to stabilize microstrip gas chambers
By sputter coating a thin-layer of low-resistive, electronically-conductive glass on various substrates (including quartz and ceramics, thin-film Pestov glass), microstrip gas chambers (MSGC) of high gain stability, low leakage current, and a high rate capability can be fabricated. This design can make the choice of substrate less important, save the cost of ion-implantation, and use less glass material.
Gong, Wen G. (Albany, CA)
The purpose of this analysis is to establish size requirements and approximate locations of Exploratory Studies Facility (ESF) test and operations alcoves, including refuge chambers during construction of the Topopah Spring (TS) loop. Preliminary conceptual layouts for non-deferred test alcoves will be developed to examine construction feasibility based on current test plans and available equipment. The final location and configuration layout for alcoves will be developed when in-situ rock conditions can be visually determined. This will be after the TBM has excavated beyond the alcove location and the rock has been exposed. The analysis will examine the need for construction of walkways and electrical alcoves in the ramps and main drift. Niches that may be required to accommodate conveyor booster drives and alignments are not included in this analysis. The analysis will develop design criteria for refuge chambers to meet MSHA requirements and will examine the strategic location of refuge chambers based on their potential use in various ESF fire scenarios. This document supersedes DI:BABE00000-01717-0200-00003 Rev 01, ''TS North Ramp Alcove and Stubout Location Analysis'' in its entirety (Reference 5-6).
John Beesley and Romeo S. Jurani
Test with cosmic rays of the GEM chambers for the LHCb muon system produced in Cagliari
The inner region of the first LHCb muon station will be equipped with twelve Gas Electron Multiplier chambers. The seven chambers produced in Cagliari were studied for several days each using cosmic rays. We measured the efficiency, timing resolution, and uniformity, cluster-size and out-of-time multiplicity. We find all seven chambers perform well.
Bonivento, W; Oldeman, R G C
The Hydriding Kinetics of Organic Hydrogen Getters
The aging of hermetically sealed systems is often accompanied by the gradual production of hydrogen gas that is a result of the decay of environmental gases and the degradation of organic materials. In particular, the oxygen, water, hydrogen ''equilibrium'' is affected by the removal of oxygen due the oxidation of metals and organic materials. This shift of the above ''equilibrium'' towards the formation of hydrogen gas, particularly in crevices, may eventually reach an explosive level of hydrogen gas or degrade metals by hydriding them. The latter process is generally delayed until the oxidizing species are significantly reduced. Organic hydrogen getters introduced by Allied Signal Aerospace Company, Kansas City Division have proven to be a very effective means of preventing hydrogen gas accumulation in sealed containers. These getters are relatively unaffected by air and environmental gases. They can be packaged in a variety of ways to fit particular needs such as porous pellets, fine or coarse [gravel] powder, or loaded into silicone rubber. The hydrogen gettering reactions are extremely irreversible since the hydrogen gas is converted into an organic hydrocarbon. These getters are based on the palladium-catalyzed hydrogenation of triple bonds to double and then single bonds in aromatic aryl compounds. DEB (1,4 bis (phenyl ethynyl) benzene) typically mixed with 25% by weight carbon with palladium (1% by weight of carbon) is one of the newest and best of these organic hydrogen getters. The reaction mechanisms are complex involving solid state reaction with a heterogeneous catalyst leading to the many intermediates, including mixed alkyl and aryl hydrocarbons with the possibilities of many isomers. The reaction kinetics mechanisms are also strongly influenced by the form in which they are packaged. For example, the hydriding rates for pellets and gravel have a strong dependence on reaction extent (i.e., DEB reduction) and a kinetic order in pressure of 0.76. Silicone rubber based DEB getters hydride at a much lower rate, have little dependence on reaction extent, have a higher kinetic order in pressure (0.87), and have a lower activation energy. The kinetics of the reaction as a function of hydrogen pressure, stoichiometry, and temperature for hydrogen and deuterium near ambient temperature (0 to 75 C) for pressures near or below 100 Pa over a wide range (in some cases, the complete) hydrogenation range are presented along with multi-dimensional rate models.
Powell, G. L.
Observations of Secondary Organic Aerosol Production and Soot Aging under Atmospheric Conditions Using a Novel Environmental Aerosol Chamber
Secondary organic aerosols (SOA) comprise a substantial fraction of the total global aerosol budget. While laboratory studies involving smog chambers have advanced our understanding of the formation mechanisms responsible for SOA, our knowledge of the processes leading to SOA production under ambient gaseous and particulate concentrations as well as the impact these aerosol types have on climate is poorly understood. Although the majority of atmospheric aerosols scatter radiation either directly or indirectly by serving as cloud condensation nuclei, soot is thought to have a significant warming effect through absorption. Like inorganic salts, soot may undergo atmospheric transformation through the vapor condensation of non-volatile gaseous species which will alter both its chemical and physical properties. Typical smog chamber studies investigating the formation and growth of SOA as well as the soot aging process are temporally limited by the initial gaseous concentrations injected into the chamber environment. Furthermore, data interpretation from such experiments is generally restricted to the singular gaseous species under investigation. This dissertation discusses the use of a new aerosol chamber designed to study the formation and growth of SOA and soot aging under atmospherically relevant conditions. The Ambient Aerosol Chamber for Evolution Studies (AACES) was deployed at three field sites where size and hygroscopic growth factor (HGF) of ammonium sulfate seed particles was monitored over time to examine the formation and growth of SOA. Similar studies investigating the soot aging process were also conducted in Houston, TX. It is shown that during the ambient growth of ammonium sulfate seed particles, as particle size increases, hygroscopic growth factors decrease considerably resulting in a significant organic mass fraction in the particle phase concluding an experiment. Observations of soot aging show an increase in measured size, HGF, mass and single scattering albedo. Ambient growth rate comparisons with chamber growth yielded similar trends verifying the use of AACES to study aerosol aging. Based on the results from this study, it is recommended that AACES be employed in future studies involving the production and growth of SOA and soot aging under ambient conditions in order to bridge the gaps in our current scientific knowledge.
Glen, Crystal
Detailed Kinetic Modeling of Gasoline Surrogate Mixtures
Real fuels are complex mixtures of thousands of hydrocarbon compounds including linear and branched paraffins, naphthenes, olefins and aromatics. It is generally agreed that their behavior can be effectively reproduced by simpler fuel surrogates containing a limited number of components. In this work, a recently revised version of the kinetic model by the authors is used to analyze the combustion behavior of several components relevant to gasoline surrogate formulation. Particular attention is devoted to linear and branched saturated hydrocarbons (PRF mixtures), olefins (1-hexene) and aromatics (toluene). Model predictions for pure components, binary mixtures and multi-component gasoline surrogates are compared with recent experimental information collected in rapid compression machine, shock tube and jet stirred reactors covering a wide range of conditions pertinent to internal combustion engines. Simulation results are discussed focusing attention on the mixing effects of the fuel components.
Mehl, M; Curran, H J; Pitz, W J; Westbrook, C K
Los Alamos honored by Española Valley Chamber of Commerce
LANL Honored By Española Valley Chamber of Commerce LANL Honored By Española Valley Chamber of Commerce Community Connections: Our link to Northern New Mexico Communities Latest Issue:Dec. 2013 - Jan. 2014 All Issues » submit Los Alamos honored by Española Valley Chamber of Commerce The Espanola Valley Chamber of Commerce recognized the Lab for its support to the chamber and the entire Espanola Valley with a President's Choice Award. February 1, 2013 dummy image Read our archives. Contacts Editor Linda Anderman Email Community Programs Office Kurt Steinhaus Email The Lab received the award for efforts in a variety of areas. In late January, the Espanola Valley Chamber of Commerce recognized the Lab for its support to the chamber and the entire Espanola Valley with a President's Choice Award. Kurt Steinhaus with the Lab's Community
Long ion chamber systems for the SLC (Stanford Linear Collider)
A Panofsky Long Ion Chamber (PLIC) is essentially a gas-filled coaxial cable, and has been used to protect the Stanford Linear Accelerator from damage caused by its electron beam, and as a sensitive diagnostic tool. This old technology has been updated and has found renewed use in the SLC. PLIC systems have been installed as beam steering aids in most parts of the SLC and are a part of the system that protects the SLC from damage by errant beams in several places. 5 refs., 3 figs., 1 tab.
Rolfe, J.; Gearhart, R.; Jacobsen, R.; Jenkins, T.; McComick, D.; Nelson, R.; Reagan, D.; Ross, M.
The Time Projection Chamber for the ALICE Experiment
The Time Projection Chamber of the ALICE Experiment has been installed in the experimental setup in the underground area at the Large Hadron Collider at CERN in Geneva. The Alice TPC ReadOut (ALTRO) chip implements intelligent signal processing on the Front-End-Electronics. During the years of 2007 and 2008 commissioning and calibration of the TPC have been carried out with cosmic rays, radioactive Krypton isotopes and with tracks produced by a UV laser system. In addition to these in this publication we present first results on energy loss measurements and on the momentum resolution.
C. Lippmann; the ALICE TPC collaboration
Money Exchange Model and a general Outlook
The Kinetic Gas Theory like two-agent money exchange models, recently introduced in the Econophysics of Wealth distributions, are revisited. The emergence of Boltzmann-Gibbs like distribution of individual money to Pareto's law in the tail of the distribution is examined in terms of 2x2 Transition matrix with a general and simple oulook. Some additional interesting results are also reported.
Gupta, A K
Accuracy of EGSnrc calculations at {sup 60}Co energies for the response of ion chambers configured with various wall materials and cavity dimensions
In this investigation, five experimental data sets are used to evaluate the ability of the EGSnrc Monte Carlo code to calculate the change in chamber response associated with changes in wall material and cavity dimension at {sup 60}Co energies. Calculations of the ratios of response per unit mass of air as a function of cavity volume for walls ranging from polystyrene to lead are generally within 1%-3% of experiments. A few exceptions, which are discussed, include 20%-30% discrepancies with experiments involving lead-walled chambers used by Attix et al. [J. Res. Natl. Bur. Stand. 60, 235-243 (1958)] and Cormack and Johns [Radiat. Res. 1, 133-157 (1954)], and 5% discrepancies for the graphite chamber of Attix et al. (relative to data for other wall materials). Simulations of the experiment by Whyte [Radiat. Res. 6, 371-379 (1957)], which varied cavity air pressure in a large cylindrical chamber, are generally within 0.5% (wall/electrode materials ranging from beryllium to copper). In all cases, the agreement between measurements and EGSnrc calculations is much better when the response as a function of cavity height or air pressure is considered for each wall material individually. High-precision measurements [Burns et al., Phys. Med. Biol. 52, 7125-7135 (2007)] of the response per unit mass as a function of cavity height for a graphite chamber are also accurately reproduced, and validate previous tests of the transport mechanics of EGSnrc. Based on the general agreement found in this work between corresponding experimental results and EGSnrc calculations it can be concluded that EGSnrc can reliably be used to calculate changes in response with changes in various wall materials and cavity dimensions at {sup 60}Co energies within a accuracy of a few percent or less.
La Russa, Daniel J.; Rogers, D. W. O. [Carleton Laboratory for Radiotherapy Physics, Ottawa Carleton Institute of Physics, Carleton University Campus, Ottawa, Ontario K1S 5B6 (Canada)
ASD General Information ASD General Information APS Resources & Information A list of useful links for APS staff and users. APS Technical Publications Links to APS technical publications. APS Publications Database The official and comprehensive source of references for APS-related journal articles, conference papers, book chapters, dissertations, abstracts, awards, invited talks, etc. Image Library A collection of APS images. Responsibilities & Interfaces for APS Technical Systems Descriptions of the responsibilities of APS technical groups and how they interface with one another. APS Procedures Operational procedures for the APS. APS Specifications Specifications and approvals for upgrades or changes to existing APS hardware and software. APS Radiation Safety Policy & Procedures Committee Minutes
Dynamic stability of spindles controlled by molecular motor kinetics
We analyze the role of the force-dependent kinetics of motor proteins in the stability of antiparallel arrays of polar filaments, such as those in the mitotic spindle. We determine the possible stable structures and show that there exists an instability associated to the collective behavior of motors that leads to the collapse of the spindle. Our analysis provides a general framework to understand several experimental observations in eukaryotic cell division.
Otger Campas; Jaume Casademunt; Ignacio Pagonabarraga
Kinetic Wave Power | Open Energy Information
Kinetic Wave Power Jump to: navigation, search Name Kinetic Wave Power Address 2861 N Tupelo St Place Midland Zip 48642 Sector Marine and Hydrokinetic Phone number 989-839-9757...
Wire-chamber radiation detector with discharge control
A wire chamber; radiation detector has spaced apart parallel electrodes and grids defining an ignition region in which charged particles or other ionizing radiations initiate brief localized avalanche discharges and defining an adjacent memory region in which sustained glow discharges are initiated by the primary discharges. Conductors of the grids at each side of the memory section extend in orthogonal directions enabling readout of the X-Y coordinates of locations at which charged particles were detected by sequentially transmitting pulses to the conductors of one grid while detecting transmissions of the pulses to the orthogonal conductors of the other grid through glow discharges. One of the grids bounding the memory region is defined by an array of conductive elements each of which is connected to the associated readout conductor through a separate resistance. The wire chamber avoids ambiguities and imprecisions in the readout of coordinates when large numbers of simultaneous or; near simultaneous charged particles have been detected. Down time between detection periods and the generation of radio frequency noise are also reduced.
Perez-Mendez, V.; Mulera, T.A.
Anechoic Chamber of the National Research Council of Canada
The anechoic chamber built recently by the National Research Council (approximately 24�17�17 ft) incorporates a number of design features which reduce substantially the cost of the structure with no sacrifice in performance. An appreciable part of the saving was achieved by a simplification in the preparation and mounting of the wedges. (The cost of treatment was $3.53 per square foot.) The wedges were sprayed with three coats of lacquer to improve the binding of the Fiberglas and thus facilitate handling and avoid shedding. The only appreciable effect on the absorption coefficient for normal incidence was to lower the cutoff frequency from 85 cps to 80 cps. The wedges were wrapped in cheese cloth which was then �stitched� by means of hot paraffin. Instead of pre?mounting the wedges on a base individual holders were stamped out of sheet metal and stapled to the furring strips. The wedges could then be mounted in about 8 sec each. The inner room is of frame construction with a removable catwalk hung from the ceiling. The performance of the completed chamber was measured by the standard inverse square law method.
N. Olson; G. J. Thiessen; E. A. G. Shaw; T. F. W. Embleton
Slag monitoring system for combustion chambers of steam boilers
The computer-based boiler performance system presented in this article has been developed to provide a direct and quantitative assessment of furnace and convective surface cleanliness. Temperature, pressure, and flow measurements and gas analysis data are used to perform heat transfer analysis in the boiler furnace and evaporator. Power boiler efficiency is calculated using an indirect method. The on-line calculation of the exit flue gas temperature in a combustion chamber allows for an on-line heat flow rate determination, which is transferred to the boiler evaporator. Based on the energy balance for the boiler evaporator, the superheated steam mass flow rate is calculated taking into the account water flow rate in attemperators. Comparing the calculated and the measured superheated steam mass flow rate, the effectiveness of the combustion chamber water walls is determined in an on-line mode. Soot-blower sequencing can be optimized based on actual cleaning requirements rather than on fixed time cycles contributing to lowering of the medium usage in soot blowers and increasing of the water-wall lifetime.
Taler, J.; Taler, D. [Cracow University of Technology, Krakow (Poland)
Oxidation Kinetics Modeling Applying Phase Field Approach
Presentation Title, Oxidation Kinetics Modeling Applying Phase Field Approach ... chemical reaction rates will increase exponentially and environmental attack�...
Modeling & Characterization of Harvestable Kinetic Energy for ...
... gov 301.975-5479. Modeling & Characterization of Harvestable Kinetic Energy for Wearable Medical Sensors. RF-enabled ...
Kinetics of Nano Ti Carbides Precipitation
About this Abstract. Meeting, Materials Science & Technology 2011. Symposium, Steel Product Metallurgy and Applications. Presentation Title, Kinetics of Nano�...
Time-dependent corrections to effective rate and event statistics in Michaelis-Menten kinetics
We generalize the concept of the geometric phase in stochastic kinetics to a noncyclic evolution. Its application is demonstrated on kinetics of the Michaelis-Menten reaction. It is shown that the nonperiodic geometric phase is responsible for the correction to the Michaelis-Menten law when parameters, such as a substrate concentration, are changing with time. We apply these ideas to a model of chemical reactions in a bacterial culture of a growing size, where the geometric correction qualitatively changes the outcome of the reaction kinetics.
Sinitsyn, N A
SEY and Surface Analysis Measurements on FNAL Main Injector Ring S/S Beam Chamber Material
Material was provided by Dr. Weiren Chou, FNAL. Both mildly-activated used, and new sections of stainless steel (type 316L) beam chamber were measured. Centimeter-sized coupons were cleanly dry-cut from the large flat surface (called ''flat side'' in the plots) and from the ID end (inside diameter of the ring, in the case of the used material) and narrow end (in the case of the new material). The unused material was ultra-soniced in acetone (to remove storage residue), then rinsed with ethanol and blown dry with filtered N{sub 2}-gas, to simulate new chamber installation final rinse. Used material was installed, as cut. Surface chemistry was measured using x-ray photoelectron spectroscopy (sometimes called ''ESCA''). With this technique, soft x-rays (1486 eV) illuminate the sample, penetrating into the surface ten microns. Photoelectrons are generated from energy levels of the constituent compounds/elements present. Those electrons, within 5 nm or so of the surface, escape without energy loss and preserve valence information about the atomic levels from which they were generated. An electron energy analyzer, of good energy resolution, measures the photoelectron energy, thereby yielding both valence (chemical) information and relative atomic abundances in the top 5 nm of surface. Using appropriate sensitivity factors, these intensities are converted to a semi-quantitative (surface atom %) concentration in the analyzed layer. As a benchmark, the limit for carbon contamination on vacuum components for UHV use at SLAC is 50 at%. That corresponds to about 8-10 monolayers of elemental carbon. XPS does not detect hydrogen because it has no electrons after bonding. Generally, hydrides do not show evidence of ''chemical shift'' of the binding energy of the metal lines.
Kirby, Robert E.; /SLAC
Barotropic Impacts of Surface Friction on Eddy Kinetic Energy and Momentum Fluxes: An Alternative to the Barotropic Governor
As the surface drag is increased in a comprehensive general circulation model (GCM), the upper-level zonal winds decrease and eddy momentum flux convergence into the jet core increases. Globally averaged eddy kinetic energy decreases, a response ...
Elizabeth A. Barnes; Chaim I. Garfinkel
The Horizontal Kinetic Energy Spectrum and Spectral Budget Simulated by a High-Resolution Troposphere�Stratosphere�Mesosphere GCM
Horizontal kinetic energy spectra simulated by high-resolution versions of the Geophysical Fluid Dynamics Laboratory SKYHI middle-atmosphere general circulation model are examined. The model versions considered resolve heights between the ground ...
John N. Koshyk; Kevin Hamilton
BIO-BAG � Type Cfj Environmental Chamber DESCRIPTION
BIO-BAG Type Cfj is a disposable, individual environmental chamber and a gas generator, consisting of one tablet of potassium borohydride-sodium bicarbonate and an ampule of hydrochloric acid, which when activated in the sealed BIO-BAG chamber provides a microaerophilic atmosphere. INTENDED USE BIO-BAG Type Cfj is designed to provide a microaerophilic environment suitable for the isolation of Campylobacter jejuni, formerly known as C. fetus subsp. jejuni (Cfj), from clinical specimens or subcultures from selective media. When used as directed, BIO-BAG Type Cfj will provide an atmosphere that has been shown to provide optimum growth of C. jejuni. 1,2 SUMMARY AND EXPLANATION Campylobacter jejuni has been recognized as a common enteric pathogen. 2,4,7,8 This organism is a true microaerophile and a capnophilic atmosphere has been shown to enhance growth. 5 Use of a selective medium containing 5 % sheep blood and a combination of antimicrobial agents and incubation at 42�C provides conditions favorable for the selective isolation of C. jejuni from intestinal flora. 3,6 Under ideal conditions, characteristic colonies may be observed in 24 to 48 h, 1,2,5 Each BIO-BAG Type Cfj system allows cultures to be set up and observed for growth individually, so that appropriate atmospheric conditions are not interrupted. Exposure to atmospheric oxygen may interfere with the growth of more oxygen-sensitive strains. 5 PRINCIPLE OF THE PROCEDURE A microaerophilic-capnophilic atmosphere is provided in each sealed BIO-BAG Type Cfj system. A self-contained generator consists of an ampule of a weak hydrochloric acid solution and a gas generator tablet. When the ampule is crushed, the tablet is then activated. A portion of atmospheric oxygen in the chamber is utilized in the reaction. The resulting atmosphere is conducive to the isolation and cultivation of C. jejuni. 1,2 Each BIO-BAG Type Cfj system is disposable and designed to be used only once.
unknown authors
On fast reactor kinetics studies
The results and the program of fast reactor core time and space kinetics experiments performed and planned to be performed at the IPPE critical facility is presented. The TIMER code was taken as computation support of the experimental work, which allows transient equations to be solved in 3-D geometry with multi-group diffusion approximation. The number of delayed neutron groups varies from 6 to 8. The code implements the solution of both transient neutron transfer problems: a direct one, where neutron flux density and its derivatives, such as reactor power, etc, are determined at each time step, and an inverse one for the point kinetics equation form, where such a parameter as reactivity is determined with a well-known reactor power time variation function. (authors)
Seleznev, E. F.; Belov, A. A. [Nuclear Safety Inst. of the Russian Academy of Sciences IBRAE (Russian Federation); Matveenko, I. P.; Zhukov, A. M.; Raskach, K. F. [Inst. for Physics and Power Engineering IPPE (Russian Federation)
From continuum Fokker-Planck models to discrete kinetic models
ABSTRACT Two theoretical formalisms are widely used in modeling mechanochemical systems such as protein motors: continuum Fokker-Planck models and discrete kinetic models. Both have advantages and disadvantages. Here we present a ��finite volume� � procedure to solve Fokker-Planck equations. The procedure relates the continuum equations to a discrete mechanochemical kinetic model while retaining many of the features of the continuum formulation. The resulting numerical algorithm is a generalization of the algorithm developed previously by Fricks, Wang, and Elston through relaxing the local linearization approximation of the potential functions, and a more accurate treatment of chemical transitions. The new algorithm dramatically reduces the number of numerical cells required for a prescribed accuracy. The kinetic models constructed in this fashion retain some features of the continuum potentials, so that the algorithm provides a systematic and consistent treatment of mechanical-chemical responses such as load-velocity relations, which are difficult to capture with a priori kinetic models. Several numerical examples are given to illustrate the performance of the method.
Jianhua Xing; Hongyun Wang; George Oster
Kinetically Dominated FRII Radio Sources
The existence of FR II objects that are kinetically dominated, the jet kinetic luminosity, $Q$, is larger than the total thermal luminosity (IR to X-ray) of the accretion flow, $L_{bol}$, is of profound theoretical interest. Such objects are not expected in most theoretical models of the central engine of radio loud AGN. Thus, establishing such a class of objects is an important diagnostic for filtering through the myriad of theoretical possibilities. This paper attempts to establish a class of quasars that have existed in a state of kinetic dominance, $R(t)\\equiv Q(t)/L_{bol}(t)>1$, at some epoch, $t$. It is argued that the 10 quasars in this article with a long term time average $Q(t)$, $\\bar{Q}$, that exceed $L_{Edd}$ are likely to have satisfied the condition $R(t)>1$ either presently or in the past based on the rarity of $L_{bol}>L_{Edd}$ quasars. Finally, the existence of these sources is discussed in the context of the theory of the central engine.
Brian Punsly
Radiation damage control in the BNL hypernuclear spectrometer drift chamber system
A high rate drift chamber system has been in use at the BNL hypernuclear spectrometer system for the past three years. Some of the chambers have accumulated charge doses up to about 0.2 C/cm-wire without showing external signs of aging. The system design and performance will be discussed as well as the results of some laboratory drift chamber aging tests. 5 refs., 9 figs.
Pile, P.H.
Charge-Focusing Readout of Time Projection Chambers
Time projection chambers (TPCs) have found a wide range of applications in particle physics, nuclear physics, and homeland security. For TPCs with high-resolution readout, the readout electronics often dominate the price of the final detector. We have developed a novel method which could be used to build large-scale detectors while limiting the necessary readout area. By focusing the drift charge with static electric fields, we would allow a small area of electronics to be sensitive to particle detection for a much larger detector volume. The resulting cost reduction could be important in areas of research which demand large-scale detectors, including dark matter searches and detection of special nuclear material. We present simulations made using the software package Garfield of a focusing structure to be used with a prototype TPC with pixel readout. This design should enable significant focusing while retaining directional sensitivity to incoming particles. We also present first experimental results and compare them with simulation.
S. J. Ross; M. T. Hedges; I. Jaegle; M. D. Rosen; I. S. Seong; T. N. Thorpe; S. E. Vahsen; J. Yamaoka
Time projection chambers (TPCs) have found a wide range of applications in particle physics, nuclear physics, and homeland security. For TPCs with high-resolution readout, the readout electronics often dominate the price of the final detector. We have developed a novel method which could be used to build large-scale detectors while limiting the necessary readout area. By focusing the drift charge with static electric fields, we would allow a small area of electronics to be sensitive to particle detection for a much larger detector volume. The resulting cost reduction could be important in areas of research which demand large-scale detectors, including dark matter searches and detection of special nuclear material. We present simulations made using the software package Garfield of a focusing structure to be used with a prototype TPC with pixel readout. This design should enable significant focusing while retaining directional sensitivity to incoming particles. We also present first experimental results and com...
Ross, S J; Jaegle, I; Rosen, M D; Seong, I S; Thorpe, T N; Vahsen, S E; Yamaoka, J
Inspector General
Office of the Under Secretary for Nuclear Security Edward B. Held (Acting) Under Secretary for Nuclear Security DEPARTMENT OF ENERGY Office of the Under Secretary for Management & Performance Vacant Under Secretary for Management and Performance Office of the Under Secretary for Science & Energy Vacant Under Secretary for Science and Energy Southwestern Power Administration Bonneville Power Administration Western Area Power Administration Southeastern Power Administration U.S. Energy Information Administration Loan Programs Office Advanced Research Projects Agency - Energy General Counsel Assistant Secretary for Congressional & Intergovernmental Affairs Chief Human Capital Officer
Modeling, Kinetics, and Energy Consumption
About this Abstract. Meeting, 2011 TMS Annual Meeting & Exhibition. Symposium , General Abstracts: Materials Processing and Manufacturing Division.
Quantum instanton evaluation of the kinetic isotope effects
A general quantum-mechanical method for computing kinetic isotope effects is presented. The method is based on the quantum instanton approximation for the rate constant and on the path integral Metropolis Monte-Carlo evaluation of the Boltzmann operator matrix elements. It computes the kinetic isotope effect directly, using a thermodynamic integration with respect to the mass of the isotope, thus avoiding the more computationally expensive process of computing the individual rate constants. The method is more accurate than variational transition-state theories or the semiclassical instanton method since it does not assume a single reaction path and does not use a semiclassical approximation of the Boltzmann operator. While the general Monte-Carlo implementation makes the method accessible to systems with a large number of atoms, we present numerical results for the Eckart barrier and for the collinear and full three-dimensional isotope variants of the hydrogen exchange reaction H+H{sub 2} {yields} H{sub 2}+H. In all seven test cases, for temperatures between 250 K and 600 K, the error of the quantum instanton approximation for the kinetic isotope effects is less than {approx}10%.
Vanicek, Jiri; Miller, William H.; Castillo, Jesus F.; Aoiz, F.Javier
General Category
Sunrise and Sunset Visual Differences Sunrise and Sunset Visual Differences Name: Joey Status: other Grade: other Country: Canada Date: Spring 2012 Question: It seems that sunrise and sunset don't look symmetric. I mean that sunsets tend to have much redder skies and sunrise is usually a bit gloomier. If you see a picture, many times you can tell if its sunrise or sunset, even though I would think they should like identical, except that the sun is either going up or going down. Why do they not appear the same but in reverse? Replies: Funny you should ask as a paper just arrived which is sure to have the answer and I will read it now....... OK, the morning sky, and the sky in general, is blue due to Rayleigh scattering [which affects short wavelengths the most] of the sun light by air molecules and other microscopic particles.
ESS 2012 Peer Review - Amber Kinetics Flywheel Energy Storage Demo - Ed Chiao, Amber Kinetics
amber_kinetics amber_kinetics DOE Peer Review September 2012 Ed Chiao, CEO amber_kinetics Amber Kinetics: Our Flywheel History Start-up launched in 2009, Stanford University Cleantech Entrepreneurship class Established a technology licensing & flywheel development partnership with LLNL; Amber Kinetics identified new material & lower-cost rotor designs for commercialization Awarded a Smart Grid Energy Storage Demonstration grant award for flywheels Awarded a matching grant for development & demonstration of flywheel technology Stanford University Lawrence Livermore National Laboratory U.S. Department of Energy California Energy Commission World-class institutions | innovative, deep flywheel technology owned by Amber Amber Kinetics, Inc. - Confidential and Proprietary, All Rights Reserved
Hydro-kinetic approach to relativistic heavy ion collisions
We develop a combined hydro-kinetic approach which incorporates hydrodynamical expansion of the systems formed in \\textit{A}+\\textit{A} collisions and their dynamical decoupling described by escape probabilities. The method corresponds to a generalized relaxation time ($\\tau_{\\text{rel}}$) approximation for Boltzmann equation applied to inhomogeneous expanding systems; at small $\\tau_{\\text{rel}}$ it also allows one to catch the viscous effects in hadronic component - hadron-resonance gas. We demonstrate how the approximation of sudden freeze-out can be obtained within this dynamical picture of continuous emission and find that hypersurfaces, corresponding to sharp freeze-out limit, are momentum dependent. The pion $m_{T}$ spectra are computed in the developed hydro-kinetic model, and compared with those obtained from ideal hydrodynamics with the Cooper-Frye isothermal prescription. Our results indicate that there does not exist a universal freeze-out temperature for pions with different momenta, and support ...
Akkelin, S V; Karpenko, Iu A; Sinyukov, Yu M
Unified Fractional Kinetic Equation and a Fractional Diffusion Equation
In earlier papers Saxena et al. (2002, 2003) derived the solutions of a number of fractional kinetic equations in terms of generalized Mittag-Leffler functions which extended the work of Haubold and Mathai (2000). The object of the present paper is to investigate the solution of a unified form of fractional kinetic equation in which the free term contains any integrable function f(t), which provides the unification and extension of the results given earlier recently by Saxena et al. (2002, 2003). The solution has been developed in terms of the Wright function in a closed form by the method of Laplace transform. Further we derive a closed-form solution of a fractional diffusion equation. The asymptotic expansion of the derived solution with respect to the space variable is also discussed. The results obtained are in a form suitable for numerical computation.
R. K. Saxena; A. M. Mathai; H. J. Haubold
Kinetic Modeling of Microbiological Processes
Kinetic description of microbiological processes is vital for the design and control of microbe-based biotechnologies such as waste water treatment, petroleum oil recovery, and contaminant attenuation and remediation. Various models have been proposed to describe microbiological processes. This editorial article discusses the advantages and limiation of these modeling approaches in cluding tranditional, Monod-type models and derivatives, and recently developed constraint-based approaches. The article also offers the future direction of modeling researches that best suit for petroleum and environmental biotechnologies.
Liu, Chongxuan; Fang, Yilin
Shale oil cracking. 1. Kinetics
Experiments were conducted to determine kinetics for thermal cracking of shale oil vapor over shale. Cracking temperatures of 504 to 610/sup 0/C and residence times of 2 to 11 seconds were used. A first-order Arrhenius rate expression and stoichiometry were obtained. Also observed were changes in the oil quality. Cracking decreased the H/C ratio, increased the nitrogen content, and decreased the pour point of the oil. Gas-phase oil cracking is contrasted to liquid-phase oil coking as a loss mechanism in oil-shale retorting.
Burnham, A.K.; Taylor, J.R.
Microreactor for fast chemical kinetics
The chemical reaction process in a T-shaped microchannel is studied experimentally through the reaction of Ca++ with a fluorescent tracer, Calcium-green. For thin channels (10 um), diffusion of species is found to behave in a way independent of the thickness direction. In such a situation, simulations of a two-dimensional reaction-diffusion model agree remarkably well with the experimental measurements. The comparison of experiments and simulations is used to measure the chemical kinetic constant, which we find to be k=3.2 x 10^5 dm^3/(mol s). Applications of the analysis to faster reactions and to micro-titration are also discussed.
Baroud, C N; Menetrier, L; Tabeling, P; Baroud, Charles N.; Okkels, Fridolin; Menetrier, Laure; Tabeling, Patrick
Combustion in Meso-scale Vortex Chambers Ming-hsun Wu*
1 Combustion in Meso-scale Vortex Chambers Ming-hsun Wu* , Yanxing Wang, Vigor Yang and Richard A) #12;2 COMBUSTION IN MESO-SCALE VORTEX CHAMBERS Ming-hsun Wu, Yanxing Wang, Vigor Yang and Richard A with the chemical energy varying from 25 to 174W. For the largest combustion volume, hydrogen and hydrocarbons
Yang, Vigor
Ionization statistics and diffusion: analytical estimate of their contribution to spatial resolution of drift chambers
The spatial resolution of a drift chamber often is the foremost design parameter. The calculation described here - a design tool - permits us to estimate the contributions of ionization statistics and diffusion to the spatial resolution when actually sampling the drift pulse waveform. Useful formulae are derived for the cylindrical and jet-chamber cell geometries.
Tarnopolsky, G.J.
Dynamic chamber armor behavior in IFE and MFE A.R. Raffray a,
Dynamic chamber armor behavior in IFE and MFE A.R. Raffray a, 1, G. Federici b , A. Hassanein c , D., Madison, WI 53706-1687, USA Abstract The chamber wall armor is subject to demanding conditions in both the requirements on armor imposed by the operating conditions in IFE and MFE, including energy deposition density
OPERATIONAL WINDOWS FOR DRY-WALL AND WETTED-WALL IFE CHAMBERS F. NAJMABADI* University the trade- offs, to develop operational windows for chamber con- cepts, and to identify high the injection process; (d) for relatively low yield targets ( 250 MJ), an operational window with no buffer gas
Commissioning an animal preference chamber for behavioral studies with laying hens exposed to atmospheric ammonia
An environmental preference chamber (EPC) with four double-tiered compartments (C1-C4), each capable of being controlled to distinct ammonia (NH"3) concentrations and temperature, was designed, fabricated and commissioned. Preference chambers are commonly ... Keywords: Ambient conditions, Animal welfare, Automatic control, Cross-contamination
G. T. Sales, A. R. Green, R. S. Gates
MHK Technologies/Multi Resonant Chambers MRC 1000 | Open Energy Information
Resonant Chambers MRC 1000 Resonant Chambers MRC 1000 < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Multi Resonant Chambers MRC 1000.jpg Technology Profile Primary Organization ORECon Technology Resource Click here Wave Technology Type Click here Oscillating Water Column Technology Readiness Level Click here TRL 5 6 System Integration and Technology Laboratory Demonstration Technology Description A 1 5MW Multi Resonant Chamber MRC using Oscillating Water Column OWC principles Consists of 3 x 500kW independent chambers each with a Dresser Rand HydroAir turbine driving an induction generator Full power conversion system delivers grid compliant power 1 5MW 33kV 60Hz to shore Device is tension moored to maximise power capture and minimise footprint All maintenance is done on board No moving parts in the water Turbines are low speed 300rpm high efficiency 75 and low noise
Integrated Chamber Design for the Laser Inertial Fusion Energy (LIFE) Engine
The Laser Inertial Fusion Energy (LIFE) concept is being designed to operate as either a pure fusion or hybrid fusion-fission system. A key component of a LIFE engine is the fusion chamber subsystem. The present work details the chamber design for the pure fusion option. The fusion chamber consists of the first wall and blanket. This integrated system must absorb the fusion energy, produce fusion fuel to replace that burned in previous targets, and enable both target and laser beam transport to the ignition point. The chamber system also must mitigate target emissions, including ions, x-rays and neutrons and reset itself to enable operation at 10-15 Hz. Finally, the chamber must offer a high level of availability, which implies both a reasonable lifetime and the ability to rapidly replace damaged components. An integrated LIFE design that meets all of these requirements is described herein.
Latkowski, J F; Kramer, K J; Abbott, R P; Morris, K R; DeMuth, J; Divol, L; El-Dasher, B; Lafuente, A; Loosmore, G; Reyes, S; Moses, G A; Fratoni, M; Flowers, D; Aceves, S; Rhodes, M; Kane, J; Scott, H; Kramer, R; Pantano, C; Scullard, C; Sawicki, R; Wilks, S; Mehl, M
The American Chamber of Commerce of Trinidad & Tobago | Department of
The American Chamber of Commerce of Trinidad & Tobago The American Chamber of Commerce of Trinidad & Tobago The American Chamber of Commerce of Trinidad & Tobago May 13, 2008 - 12:00pm Addthis Remarks As Prepared for Delivery by Secretary Bodman Thank you, Raymond. I appreciate the Chamber organizing this gathering this morning. The American Chamber here on Trinidad and Tobago is an important regional voice in support of the free market, so I want to commend you for hosting the Business Future of the Americas conference next month. Having spent most of my career in the private sector, it is always rewarding to be among colleagues from the business community. I'm also quite pleased to be back in Trinidad & Tobago, having done business here during my time at Cabot Corporation. I've always been impressed with this nation's government, its people and
U.S. Chamber of Commerce Biofuels Dialogue Series: Outlook for an Emerging
Chamber of Commerce Biofuels Dialogue Series: Outlook for an Chamber of Commerce Biofuels Dialogue Series: Outlook for an Emerging Global Biofuels Market U.S. Chamber of Commerce Biofuels Dialogue Series: Outlook for an Emerging Global Biofuels Market January 29, 2008 - 10:53am Addthis Remarks as Prepared For Delivery by Secretary Bodman Thank you very much, Bruce, for that kind introduction. My thanks also to Tom Donahue and the leadership of the Chamber for inviting me to be with you today. I was quite pleased to hear that the Chamber was sponsoring this event. As anyone who knows me - or has heard me speak recently - can tell you, the biofuels industry is a favorite topic of mine. In my view, advanced biofuels offer tremendous promise for helping our nation to bring about a new energy future-one that is cleaner, more sustainable, more affordable,
Aluminium Dissolution Kinetics in Caustic Media
� �uti?, V. and Stumm, W. (1984) Effect of organic acids and fluoride on the dissolution kinetics of hydrous alumina. A model study using the rotating disk
Nanocrystallization Reactions and Kinetics, Chemical Partitioning ...
Primary nanocrystallization reactions and kinetics will be discussed for selected FeCo-based ... Search of Half-Metallic Heusler Alloys and their Applications to�...
Thermodynamic and Kinetic Simulation and Experimental Results ...
Through the use of thermodynamic and kinetic modeling software, NETL has designed a systematic method that has been successfully developed to design an�...
Investigating Grain Boundary Structure-Kinetic Property ...
Abstract Scope, Grain boundary energy landscapes contain all the information that is required to describe the kinetic behavior of grain boundaries (GBs).
Atlas chamber, power flow channel, and diagnostic interface design
The Atlas pulsed-power machine, presently being designed at Los Alamos, will deliver a pulse of {approximately} 45 MA, in 4--5 {micro}sec, with energies of up to 6 MJ (from a bank of 36 MJ maximum) to a load assembly, located in vacuum. Design considerations for the vacuum vessel, power flow channel from the vessel inward, are presented. In contrast to Sandia`s PBFA II-Z, where 20 MA currents and 2--2.5 MJ of energy are delivered to ({approximately} 15 mg) loads in {approximately} 100 nsec, the Atlas structures will have to be designed for longer timescales and higher energies to drive heavy lines ({approximately} 70 g). Design issues for the chamber include materials stresses, formation of (and protection from) debris and molten jets, impulse loading, and survivability and ease of replacement of internal structures. For the power flow channel designs, issues are minimizing inductance, preventing movement of conductors during and after firing, damage mitigation, reducing the cost of materials and installation, and electrical insulation. A key issue for damage mitigation is the radius within which total destruction of material objects occurs. Choices of vessel size, insulator materials, cost and ease of manufacturing, and mechanical stability issues are presently in the conceptual design phase. Typical access requirements for diagnostics (including radial and axial X-ray backlighting, flux loops, spectroscopy, interferometry, bolometry, etc.) are provided for in the design.
Wurden, G.A.; Davis, H.A.; Taylor, A.; Bowman, D.; Ballard, E.; Ney, S.; Scudder, D.; Trainor, J.
Geologic evidence for a magma chamber beneath Newberry Volcano, Oregon
At Newberry Volcano, central Oregon, more than 0.5 m.y. of magmatic activity, including caldera collapse and renewed caldera-filling volcanism, has created a structural and thermal chimney that channels magma ascent. Holocene rhyolitic eruptions (1) have been confined mainly within the caldera in an area 5 km in diameter, (2) have been very similar in chemical composition, phenocryst mineralogy, and eruptive style, and (3) have occurred as recently as 1300 years ago, with repose periods of 2000--3000 years between eruptions. Holocene basaltic andesite eruptions are widespread on the flanks but are excluded from the area of rhyolitic volcanism. Basaltic andesite in fissures at the edge of the rhyolite area has silicic inclusions and shows mixed basalt-rhyolite magma relations. These geologic relations and the high geothermal gradient that characterizes the lower part of a drill hole in the caldera (U.S. Geological Survey Newberry 2) indicate that a rhyolitic magma chamber has existed beneath the caldera throughout the Holocene. Its longevity probably is a result of intermittent underplating by basaltic magma.
Macleod, N.S.; Sherrod, D.R.
Chemical kinetics and oil shale process design
Oil shale processes are reviewed with the goal of showing how chemical kinetics influences the design and operation of different processes for different types of oil shale. Reaction kinetics are presented for organic pyrolysis, carbon combustion, carbonate decomposition, and sulfur and nitrogen reactions.
Burnham, A.K.
ERNSTMORITZARNDTUNIVERSITAT Absolute number density and kinetic analysis
plasma-chemical reactions. Therefore, from the analysis of their kinetics, one can learn more about of the technical applications, many plasmachemical processes within the discharges as well as mechanisms determines all electron induced plasma-chemical processes and hence influences the kinetics of species
Greifswald, Ernst-Moritz-Arndt-Universität
Kinetics of Enzymatic Depolymerization of Guar Galactomannan
is used as a rheology modifier in many of its applications, previous kinetic studies have been limitedKinetics of Enzymatic Depolymerization of Guar Galactomannan Shamsheer Mahammad, Robert K. Prud'homme, George W. Roberts,*, and Saad A. Khan*, Department of Chemical and Biomolecular Engineering, North
Khan, Saad A.
Characterization of a multi-axis ion chamber array
Purpose: The aim of this work was to characterize a multi-axis ion chamber array (IC PROFILER; Sun Nuclear Corporation, Melbourne, FL USA) that has the potential to simplify the acquisition of LINAC beam data. Methods: The IC PROFILER (or panel) measurement response was characterized with respect to radiation beam properties, including dose, dose per pulse, pulse rate frequency (PRF), and energy. Panel properties were also studied, including detector-calibration stability, power-on time, backscatter dependence, and the panel's agreement with water tank measurements [profiles, fractional depth dose (FDD), and output factors]. Results: The panel's relative deviation was typically within ({+-}) 1% of an independent (or nominal) response for all properties that were tested. Notable results were (a) a detectable relative field shape change of {approx}1% with linear accelerator PRF changes; (b) a large range in backscatter thickness had a minimal effect on the measured dose distribution (typically less than 1%); (c) the error spread in profile comparison between the panel and scanning water tank (Blue Phantom, CC13; IBA Schwarzenbruck, DE) was approximately ({+-}) 0.75%. Conclusions: The ability of the panel to accurately reproduce water tank profiles, FDDs, and output factors is an indication of its abilities as a dosimetry system. The benefits of using the panel versus a scanning water tank are less setup time and less error susceptibility. The same measurements (including device setup and breakdown) for both systems took 180 min with the water tank versus 30 min with the panel. The time-savings increase as the measurement load is increased.
Simon, Thomas A.; Kozelka, Jakub; Simon, William E.; Kahler, Darren; Li, Jonathan; Liu, Chihray [Department of Nuclear and Radiological Engineering, University of Florida, 202 Nuclear Science Building, Gainesville, Florida 32611-8300 (United States); Department of Radiation Oncology, Health Science Center, University of Florida, P.O. Box 100385, Gainesville, Florida 32610-0385 (United States) and Sun Nuclear Corporation, 425-A Pineda Court, Melbourne, Florida 32940 (United States); Sun Nuclear Corporation, 425-A Pineda Court, Melbourne, Florida 32940 (United States); Department of Radiation Oncology, Health Science Center, University of Florida, P.O. Box 100385, Gainesville, Florida 32610-0385 (United States)
Kinetic theory of the interdiffusion coefficient in dense plasmas
Naive applications of Spitzer's theory to very dense plasmas can lead to negative diffusion coefficients. The interdiffusion coefficients in Binary Ionic Mixtures (two species of point ions in a uniform neutralizing background) have been calculated recently using molecular dynamics techniques. These calculations can provide useful benchmarks for theoretical evaluations of the diffusion coefficient in dense plasma mixtures. This paper gives a brief description of a kinetic theoretic approximation to the diffusion coefficient which generalizes Spitzer to high density and is in excellent agreement with the computer simulations. 15 refs., 1 fig., 2 tabs.
Boercker, D.B.
Split kinetic energy method for quantum systems with competing potentials
For quantum systems with competing potentials, the conventional perturbation theory often yields an asymptotic series and the subsequent numerical outcome becomes uncertain. To tackle such a kind of problems, we develop a general solution scheme based on a new energy dissection idea. Instead of dividing the potential energy into 'unperturbed' and 'perturbed' terms, a partition of the kinetic energy is performed. By distributing the kinetic energy term in part into each individual potential, the Hamiltonian can be expressed as the sum of the subsystem Hamiltonians with respective competing potentials. The total wavefunction is expanded by using a linear combination of the basis sets of respective subsystem Hamiltonians. We first illustrate the solution procedure using a simple system consisting of a particle under the action of double {delta}-function potentials. Next, this method is applied to the prototype systems of a charged harmonic oscillator in strong magnetic field and the hydrogen molecule ion. Compared with the usual perturbation approach, this new scheme converges much faster to the exact solutions for both eigenvalues and eigenfunctions. When properly extended, this new solution scheme can be very useful for dealing with strongly coupling quantum systems. - Highlights: Black-Right-Pointing-Pointer A new basis set expansion method is proposed. Black-Right-Pointing-Pointer Split kinetic energy method is proposed to solve quantum eigenvalue problems. Black-Right-Pointing-Pointer Significant improvement has been obtained in converging to exact results. Black-Right-Pointing-Pointer Extension of such methods is promising and discussed.
Mineo, H.; Chao, Sheng D., E-mail: email@example.com
Kinetic advantage of controlled intermediate nuclear fusion
The dominated process of controlled fusion is to let nuclei gain enough kinetic energy to overcome Coulomb barrier. As a result, a fusion scheme can consider two factors in its design: to increase kinetic energy of nuclei and to alter the Coulomb barrier. Cold Fusion and Hot fusion are all one-factor schemes while Intermediate Fusion is a twofactors scheme. This made CINF kinetically superior. Cold Fusion reduces deuteron-deuteron distance, addressing Coulomb barrier, and Hot Fusion heat up plasma into extreme high temperature, addressing kinetic energy. Without enough kinetic energy made Cold Fusion skeptical. Extreme high temperature made Hot Fusion very difficult to engineer. Because CIFN addresses both factors, CIFN is a more promising technique to be industrialized.
Guo Xiaoming [Physics and Computer Science Department, Wilfrid Laurier University, Waterloo, Ontario, N2L 3C5 (Canada)
Resistive wall heating due to image current on the beam chamber for a superconducting undulator.
The image-current heating on the resistive beam chamber of a superconducting undulator (SCU) was calculated based on the normal and anomalous skin effects. Using the bulk resistivity of copper for the beam chamber, the heat loads were calculated for the residual resistivity ratios (RRRs) of unity at room temperature to 100 K at a cryogenic temperature as the reference. Then, using the resistivity of the specific aluminum alloy 6053-T5, which will be used for the SCU beam chamber, the heat loads were calculated. An electron beam stored in a storage ring induces an image current on the inner conducting wall, mainly within a skin depth, of the beam chamber. The image current, with opposite charge to the electron beam, travels along the chamber wall in the same direction as the electron beam. The average current in the storage ring consists of a number of bunches. When the pattern of the bunched beam is repeated according to the rf frequency, the beam current may be expressed in terms of a Fourier series. The time structure of the image current is assumed to be the same as that of the beam current. For a given resistivity of the chamber inner wall, the application ofthe normal or anomalous skin effect will depend on the harmonic numbers of the Fourier series of the beam current and the temperature of the chamber. For a round beam chamber with a ratius r, much larger than the beam size, one can assume that the image current density as well as the density square, may be uniform around the perimeter 2{pi}r. For the SCU beam chamber, which has a relatively narrow vertical gap compared to the width, the effective perimeter was estimated since the heat load should be proportional to the inverse of the perimeter.
Kim, S. H. (Accelerator Systems Division (APS))
Four-Button BPM Coefficients in Cylindrical and Elliptic Beam Chambers
Beam position monitor (BPM) coefficients are calculated from induced charges on four-button BPMs in circular and elliptic beam chambers for ?>> 1. Since the beam chamber cross-section for the APS storage ring is different from an exact elliptic geometry, numerical values of the BPM coefficients and their inversions are computed from two-dimensional electrostatic field distributions inside an exact geometry of the beam chamber. Utilizing Green�s reciprocation theorem, a potential value is applied to the buttons rather than changing the beam position, and potential distributions corresponding to the beam positions are then computed. 1. Cylindrical Chamber A charged particle beam of short bunches induces charges on the beam chamber wall. Due to the Lorentz contraction, for ?>> 1, where ? is the relativistic factor, these charges have the same longitudinal intensity modulation as the beam. The electromagnetic fields associated with the beam are obtained by the Lorentz transformation from the fixed lab frame F to a moving reference frame F', where the charged beam is at rest [1, 2]. The field distribution inside the beam chamber becomes an electrostatic problem in the moving reference frame. Here we assume that the buttons are installed flush with the inner surface of the beam chamber, with the chamber having constant crosssection and the chamber wall at a uniform potential. For the charge density of a filament beam located at (xo,yo) in the transverse plane of the Cartesian coordinates and moving with a wave number k in the longitudinal direction z in the lab frame F, ? = ? ( x, y) cos k( z ? vt); (1) k
S. H. Kim
Four-button BPM coefficients in cylindrical and elliptic beam chambers.
Beam position monitor (BPM) coefficients are calculated from induced charges on four-button BPMs in circular and elliptic beam chambers for {gamma} >>1. Since the beam chamber cross-section for the APS storage ring is different from an exact elliptic geometry, numerical values of the BPM coefficients and their inversions are computed from two-dimensional electrostatic field distributions inside an exact geometry of the beam chamber. Utilizing Green's reciprocation theorem, a potential value is applied to the buttons rather than changing the beam position, and potential distributions corresponding to the beam positions are then computed.
Kim, S.H.
Enclosed Chambers for Humidity Control And Sample Containment in Fiber Diffraction
A chamber and stretch frame for making fibers for diffraction is described. The chamber is made from a simple plastic cuvette with silicon nitride windows. It is suitable for maintaining constant humidity during fiber drying and data collection, and allows stretching of the fiber and exposure to magnetic fields during sample preparation. If necessary, it provides primary containment for toxic and infectious biological materials. The chamber has been used in fiber diffraction experiments with filamentous plant viruses and a yeast prion protein, and is shown to produce excellent orientation and to maintain hydration and order at the molecular level.
McDonald, M.; Kendall, A.; Tanaka, M.; Weissman, J.S.; Stubbs, G.
Development of Detailed Kinetic Models for Fischer-Tropsch Fuels
Fischer-Tropsch (FT) fuels can be synthesized from a syngas stream generated by the gasification of biomass. As such they have the potential to be a renewable hydrocarbon fuel with many desirable properties. However, both the chemical and physical properties are somewhat different from the petroleum-based hydrocarbons that they might replace, and it is important to account for such differences when considering using them as replacements for conventional fuels in devices such as diesel engines and gas turbines. FT fuels generally contain iso-alkanes with one or two substituted methyl groups to meet the pour-point specifications. Although models have been developed for smaller branched alkanes such as isooctane, additional efforts are required to properly capture the kinetics of the larger branched alkanes. Recently, Westbrook et al. developed a chemical kinetic model that can be used to represent the entire series of n-alkanes from C{sub 1} to C{sub 16} (Figure 1). In the current work, the model is extended to treat 2,2,4,4,6,8,8-heptamethylnonane (HMN), a large iso-alkane. The same reaction rate rules used in the iso-octane mechanism were incorporated in the HMN mechanism. Both high and low temperature chemistry was included so that the chemical kinetic model would be applicable to advanced internal combustion engines using low temperature combustion strategies. The chemical kinetic model consists of 1114 species and 4468 reactions. Concurrently with this effort, work is underway to improve the details of specific reaction classes in the mechanism, guided by high-level electronic structure calculations. Attention is focused upon development of accurate rate rules for abstraction of the tertiary hydrogens present in branched alkanes and properly accounting for the pressure dependence of the ?-scission, isomerization, and R + O{sub 2} reactions.
Westbrook, C K; Pitz, W J; Carstensen, H; Dean, A M
T T A T E OF CONNECTICUT E X E C U T I V E CHAMBERS M . JODI R E L L GOVERNOR The Honorable Steven Chu, Secretary United States Department of Energy 1000 Independence Avenue, S. W. Washington, D.C. 20585 March 23,2009 Dear Secretary Chu: Re: State Energy Program Assurances In accordance with Section 41 0 of the American Recovery and Reinvestment Act of 2009,I hereby notify you that I have obtained necessary assurances that each of the following will occur: (1) The applicable State regulatory authority will seek to implement, in appropriate proceedings for each electric and gas utility, with respect to which the State regulatory authority has ratemaking authority, a general policy that ensures that utility financial incentives are aligned with helping their customers use energy more efficiently and that provide timely cost recovery
Global optimization algorithms for semi-infinite and generalized semi-infinite programs
The goals of this thesis are the development of global optimization algorithms for semi-infinite and generalized semi-infinite programs and the application of these algorithms to kinetic model reduction. The outstanding ...
Lemonidis, Panayiotis
Kinetic description of rotating Tokamak plasmas with anisotropic temperatures in the collisionless regime
A largely unsolved theoretical issue in controlled fusion research is the consistent kinetic treatment of slowly-time varying plasma states occurring in collisionless and magnetized axisymmetric plasmas. The phenomenology may include finite pressure anisotropies as well as strong toroidal and poloidal differential rotation, characteristic of Tokamak plasmas. Despite the fact that physical phenomena occurring in fusion plasmas depend fundamentally on the microscopic particle phase-space dynamics, their consistent kinetic treatment remains still essentially unchallenged to date. The goal of this paper is to address the problem within the framework of Vlasov-Maxwell description. The gyrokinetic treatment of charged particles dynamics is adopted for the construction of asymptotic solutions for the quasi-stationary species kinetic distribution functions. These are expressed in terms of the particle exact and adiabatic invariants. The theory relies on a perturbative approach, which permits to construct asymptotic analytical solutions of the Vlasov-Maxwell system. In this way, both diamagnetic and energy corrections are included consistently into the theory. In particular, by imposing suitable kinetic constraints, the existence of generalized bi-Maxwellian asymptotic kinetic equilibria is pointed out. The theory applies for toroidal rotation velocity of the order of the ion thermal speed. These solutions satisfy identically also the constraints imposed by the Maxwell equations, i.e., quasi-neutrality and Ampere's law. As a result, it is shown that, in the presence of nonuniform fluid and EM fields, these kinetic equilibria can sustain simultaneously toroidal differential rotation, quasi-stationary finite poloidal flows and temperature anisotropy.
Cremaschini, Claudio [International School for Advanced Studies (SISSA) and INFN, Trieste (Italy); Tessarotto, Massimo [Department of Mathematics and Informatics, University of Trieste (Italy)
Model simplification of chemical kinetic systems under uncertainty
This thesis investigates the impact of uncertainty on the reduction and simplification of chemical kinetics mechanisms. Chemical kinetics simulations of complex fuels are very computationally expensive, especially when ...
Coles, Thomas Michael Kyte
A Rapid-Circulation Evaporation Chamber for Measuring Bulk Stomatal Resistance
A relatively simple method is described for determining evaporation of short vegetation at any moment of time. The method is based on the measurement of bulk stomatal resistance of the crop with an evaporation chamber. Once this quantity is known,...
W. Kohsiek
Method of correcting eddy current magnetic fields in particle accelerator vacuum chambers
A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations in the particle beam.
Danby, Gordon T. (Wading River, NY); Jackson, John W. (Shoreham, NY)
A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations (dB/dt) in the particle beam.
Danby, G.T.; Jackson, J.W.
Potential applications of the natural design of internal explosion chambers in the bombardier beetle (Carabidae, Brachinus)
The Bombardier Beetle (Carabidae, Brachinus) has a unique form of defense mechanism which involves the explosive mixing of hydroquinones and hydrogen peroxide in its internal explosion chambers and using the resultant high ...
Lai, Changquan
Condensation Coefficient Measurement for Water in the UMR Cloud Simulation Chamber
A systematic series of condensation coefficient measurements of water have been made using the University of Missouri�Rolla cooled-wall expansion chamber which simulates the thermodynamics of cloud. This coefficient is seen to decrease from a ...
D. E. Hagen; J. Schmitt; M. Trueblood; J. Carstens; D. R. White; D. J. Alofs
Space Chamber Reaches Cold Target at Unprecedented Efficiency | U.S. DOE
Space Chamber Reaches Cold Target at Unprecedented Efficiency Space Chamber Reaches Cold Target at Unprecedented Efficiency Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: email@example.com More Information » October 2012 Space Chamber Reaches Cold Target at Unprecedented Efficiency Thomas Jefferson Laboratory lends expertise in cryogenics developments. Print Text Size: A A A Subscribe FeedbackShare Page Click to enlarge photo. Enlarge Photo Image courtesy of NASA NASA's Space Environment Simulation Lab Chamber A, which is used by the
Neutron And Gamma Detector Using An Ionization Chamber With An Integrated
Neutron And Gamma Detector Using An Ionization Chamber Neutron And Gamma Detector Using An Ionization Chamber Neutron And Gamma Detector Using An Ionization Chamber With An Integrated Body And Moderator A detector for detecting neutrons and gamma radiation includes a cathode that defines an interior surface and an interior volume. Available for thumbnail of Feynman Center (505) 665-9090 Email Neutron And Gamma Detector Using An Ionization Chamber With An Integrated Body And Moderator A detector for detecting neutrons and gamma radiation includes a cathode that defines an interior surface and an interior volume. A conductive neutron-capturing layer is disposed on the interior surface of the cathode and a plastic housing surrounds the cathode. A plastic lid is attached to the housing and encloses the interior volume of the cathode forming an
Modeling of Reactor Kinetics and Dynamics
In order to model a full fuel cycle in a nuclear reactor, it is necessary to simulate the short time-scale kinetic behavior of the reactor as well as the long time-scale dynamics that occur with fuel burnup. The former is modeled using the point kinetics equations, while the latter is modeled by coupling fuel burnup equations with the kinetics equations. When the equations are solved simultaneously with a nonlinear equation solver, the end result is a code with the unique capability of modeling transients at any time during a fuel cycle.
Matthew Johnson; Scott Lucas; Pavel Tsvetkov
Dual-chamber plasma deposition of A-Si:H solar cells at high rates using disilane
The use of a separated chamber deposition system for the fabrication of a-Si:H solar cells from disilane at high deposition rates results in a substantial improvement in short circuit current compared to that obtained from a single-chamber system. The spectral responses of cells fabricated in the dual-chamber mode are compared to those made in the single-chamber mode. The results are interpreted by assuming that the rate of removal of boron contaminants from the chamber is independent of deposition rate.
Rajeswaran, G.; Vanier, P.E.; Corderman, R.R.; Kampas, F.J.
Directional Detection of Fast Neutrons Using a Time Projection Chamber
Spontaneous fission in Special Nuclear Material (SNM) such as plutonium and highly enriched uranium (HEU) results in the emission of neutrons with energies in the MeV range (hereafter 'fast neutrons'). These fast neutrons are largely unaffected by the few centimeters of intervening high-Z material that would suffice for attenuating most emitted gamma rays, while tens of centimeters of hydrogenous materials are required to achieve substantial attenuation of neutron fluxes from SNM. Neutron detectors are therefore an important complement to gamma-ray detectors in SNM search and monitoring applications. The rate at which SNM emits fast neutrons varies from about 2 per kilogram per second for typical HEU to some 60,000 per kilogram per second for metallic weapons grade plutonium. These rates can be compared with typical sea-level (cosmogenic) neutron backgrounds of roughly 5 per second per square meter per steradian in the relevant energy range [1]. The fact that the backgrounds are largely isotropic makes directional neutron detection especially attractive for SNM detection. The ability to detect, localize, and ultimately identify fast neutron sources at standoff will ultimately be limited by this background rate. Fast neutrons are particularly well suited to standoff detection and localization of SNM or other fast neutrons sources. Fast neutrons have attenuation lengths of about 60 meters in air, and retain considerable information about their source direction even after one or two scatters. Knowledge of the incoming direction of a fast neutron, from SNM or otherwise, has the potential to significantly improve signal to background in a variety of applications, since the background arriving from any one direction is a small fraction of the total background. Imaging or directional information therefore allows for source detection at a larger standoff distance or with shorter dwell times compared to nondirectional detectors, provided high detection efficiency can be maintained. Directional detection of neutrons has been previously considered for applications such as controlled fusion neutron imaging [2], nuclear fuel safety research [3], imaging of solar neutrons and SNM [4], and in nuclear science [5]. The use of scintillating crystals and fibers has been proposed for directional neutron detection [6]. Recently, a neutron scatter camera has been designed, constructed, and tested for imaging of fast neutrons, characteristic for SNM material fission [7]. The neutron scatter camera relies on the measurement of the proton recoil angle and proton energy by time of flight between two segmented solid-state detectors. A single-measurement result from the neutron scatter camera is a ring containing the possible incident neutron direction. Here we describe the development and commissioning of a directional neutron detection system based on a time projection chamber (TPC) detector. The TPC, which has been widely used in particle and nuclear physics research for several decades, provides a convenient means of measuring the full 3D trajectory, specific ionization (i.e particle type) and energy of charged particles. For this application, we observe recoil protons produced by fast neutron scatters on protons in hydrogen or methane gas. Gas pressures of a few ATM provide reasonable neutron interaction/scattering rates.
Bowden, N; Heffner, M; Carosi, G; Carter, D; Foxe, M; Jovanovic, I
Rainfall Kinetic Energy in Eastern Australia
Rainfall kinetic energy is a commonly used climatic parameter for the prediction of soil erosion by water. Such a parameter is difficult to measure and is usually estimated from relationships established between rainfall energy and rainfall ...
Colin John Rosewell
Kinetic Energy LLC | Open Energy Information
Name Kinetic Energy LLC Place Texas Utility Id 56210 Utility Location Yes Ownership R NERC ERCOT Yes ISO Ercot Yes Activity Retail Marketing Yes References EIA Form EIA-861...
AER NY Kinetics LLC | Open Energy Information
Database. This company is involved in the following MHK Projects: Ogdensburg Kinetic Energy Project This article is a stub. You can help OpenEI by expanding it. Retrieved...
The Multiplexed Chemical Kinetic Photoionization Mass Spectrometer: A New Approach To Isomer-resolved Chemical Kinetics
instruments applied to analysis of complex chemical mixturesrelies on chemical separation (by chromatography) into pureThe multiplexed chemical kinetic photoionization mass
Osborne, David L.
Kinetic Theory of Plasma Waves - Part III: Inhomogeneous Plasma
P. U. Lamalle
Kinetic Theory of Plasma Waves - Part I: Introduction
Kinetic instability of drift-Alfven waves in solar corona and stochastic heating
The solar atmosphere is structured and inhomogeneous both horizontally and vertically. The omnipresence of coronal magnetic loops implies gradients of the equilibrium plasma quantities like the density, magnetic field and temperature. These gradients are responsible for the excitation of drift waves that grow both within the two-component fluid description (in the presence of collisions and without it) and within the two-component kinetic descriptions (due to purely kinetic effects). In the present work the effects of the density gradient in the direction perpendicular to the magnetic field vector are investigated within the kinetic theory, in both electrostatic and electromagnetic regimes. The electromagnetic regime implies the coupling of the gradient-driven drift wave with the Alfven wave. The growth rates for the two cases are calculated and compared. It is found that, in general, the electrostatic regime is characterized by stronger growth rates, as compared with the electromagnetic perturbations. Also d...
Vranjes, J
Vacuum chamber of the injector synchrotron for the Advanced Photon Source
The 40 chambers of the 368 m, 7-GeV injector synchrotron of the Advanced Photon Source are made from 1 mm-thick, 316LN stainless steel tubing. Tubes are cold-drawn to an elliptical shape with inside major and minor axes of 6 cm and 3.7 cm, respectively. This results in a thin metallic chamber without corrugations, which allows maximum beam space in the magnets and withstands atmospheric pressure. Sections of the chamber are bent to match the radius of curvature (33.3 m) of the beam over the entire effective length of the dipole magnets. A modified orbital welder is used to join sections of tubing. The chambers and the pumping system required to achieve a pressure of 10{sup {minus}9} Torr are described. A straight section of chamber tubing was tested under external pressure up to 60 psig. At 15 psig, the resulting deflection at the minor half axis was 0.2mm and a maximum compressive stress of 13,500 psi was measured. Tube deformation remained in the elastic region up to {approximately}38 psig. 4 refs., 2 figs.
Benaroya, R.; Dortwegt, R.
Single Particle Laser Mass Spectrometry Applied to Differential Ice Nucleation Experiments at the AIDA Chamber
Experiments conducted at the Aerosol Interactions and Dynamics in the Atmosphere (AIDA) chamber located in Karlsruhe, Germany permit investigation of particle properties that affect the nucleation of ice at temperature and water vapor conditions relevant to cloud microphysics and climate issues. Ice clouds were generated by heterogeneous nucleation of Arizona test dust (ATD), illite, and hematite and homogeneous nucleation of sulfuric acid. Ice crystals formed in the chamber were inertially separated from unactivated, or �interstitial� aerosol particles with a pumped counterflow virtual impactor (PCVI), then evaporated. The ice residue (i.e., the aerosol which initiated ice nucleation plus any material which was scavenged from the gas- and/or particle-phase), was chemically characterized at the single particle level using a laser ionization mass spectrometer. In this manner the species that first nucleated ice could be identified out of a mixed aerosol population in the chamber. Bare mineral dust particles were more effective ice nuclei (IN) than similar particles with a coating. Metallic particles from contamination in the chamber initiated ice nucleation before other species but there were few enough that they did not compromise the experiments. Nitrate, sulfate, and organics were often detected on particles and ice residue, evidently from scavenging of trace gas-phase species in the chamber. Hematite was a more effective ice nucleus than illite. Ice residue was frequently larger than unactivated test aerosol due to the formation of aggregates due to scavenging, condensation of contaminant gases, and the predominance of larger aerosol in nucleation.
Gallavardin, S. J.; Froyd, Karl D.; Lohmann, U.; Moehler, Ottmar; Murphy, Daniel M.; Cziczo, Dan
Photon stimulated desorption measurement of an extruded aluminum beam chamber for the Advanced Photon Source
The Advanced Photon Source (APS), presently being commisioned, will produce X-ray s of unprecedented brightness. The high energy ring of the APS is a 7 GeV positron storage ring, 1104 meters in circumference designed to operate at less than 10{sup {minus}9} Torr with 300 ma of beam and a greater than 10 hour lifetime. The storage ring vacuum chamber is constructed from an extruded 6063 aluminum alloy. During the construction phase, a 2.34 m long section of the APS extruded aluminum chamber was set up on National Synchrotron Light Source (NSLS) X-ray Beamlline X28A and Photon Stimulated Desorption (PSD) was measured. Cleaning and preparation of the chamber was identical to that of the APS construction. In addition to the chamber, small samples of M, Be, and Cu were also exposed to white light having a critical energy of 5 keV. In addition to PSD, measurements were made of specular and diffuse scattering of photons. The chamber and samples were each exposed to a dose greater than 10{sup 23} photons per meter. Desorption yields for H{sub 2}, CO, CO{sub 2}, CH{sub 4} and H{sub 2}0 are reported as a function of accumulated flux, critical energy, incidence angle, and preparation. These results are compared with previous results for aluminum on NSLS Beamlline U1OB and PSD results of other laboratories published for aluminum.
Foerster, C.L.; Lanni, C. [Brookhaven National Lab., Upton, NY (United States); Noonan, J.R.; Rosenberg, R.A. [Argonne National Lab., IL (United States)
Kinetics of PBX9404 Aging
PBX 9404 is an early formulation of HMX from which we can learn about the effects of aging in the weapons stockpile. Of particular interest is the presence of 3% nitrocellulose in PBX 9404 as an energetic binder. Nitrocellulose is used pervasively in smokeless gunpowders and was formerly used extensively in the film and art preservation industries. It is well known that nitrocellulose decomposes autocatalytically, and stabilizers, such as the diphenylamine used in PBX 9404, are used to retard its decomposition. Even so, its lifetime is still limited, and the reactions eventually leading to catastrophic autocatalysis are still not understood well despite years of work. In addition to reducing the available energy in the explosive, degradation of nitrocellulose affects the mechanical properties of the pressed PBX 9404 parts by the associated reduction in molecular weight, which reduces the strength of the binder. A structural formula for a monomer of the nitrocellulose used in PBX 9404 is shown. The initial nitration level is 2.3 of 3.0 possible sites, and they have different reactivities. Degradation of nitrocellulose affects many properties. As an aid in examining historical chemical analysis data, several measures of degradation are given for the simple replacement of a nitro group with a hydrogen. The weight percent of nitrocellulose remaining for an initial concentration of 3% as used in PBX 9404 is also given. Of course, the real degradation reaction is more complicated, including chain scission and crosslinking reactions giving other gas species. During the course of this work, we spent considerable time addressing the question, ''Why is PBX 9404 blue?'' There was actually considerable controversy in the color evolution with aging, and the situation was clarified by Ben Richardson at Pantex. Workers there assured us that PBX 9404 starts with an ivory color. Drying the prill prior to pressing turns it a mottled blue, and well-preserved prill samples retain a blue color decades after formulation. Subsequently, heat and light both send it through a progression of colors from grayish blue, blue-green, green, brown, dirty yellow, mottled tan, and eventually pale tan. The progression is accelerated by oxygen and possibly moisture, as has been shown in several accelerated aging studies. The precise compounds causing the color evolution are uncertain, but they are undoubtedly a progression of quinoidal, nitroso, and nitrated DPA compounds. For example, paranitroso DPA is deep blue. Unfortunately, the location of various nitrated DPAs, which ranged from yellow to orange to red to brown and which were used by Pantex as analytical standards in the 1970s, is not currently known. While the color change is indicative of aging, it is by no means a quantitative measure of the extent of nitrocellulose degradation. Inspection of the literature yielded a variety of kinetic models, and the activation energy typically ranges from 25-35 kcal/mol for T<100 C. This literature qualitatively predicts times for 30% decomposition ranging from a few days at 100 C to 1-2 years at 50 C to 50 years at room temperature. To develop a quantitative model, we used the data of Leider and Seaton, which were collected at conditions most closely matching stockpile conditions for any data set we had available. They used PBX 9404 heated as pressed pellets in closed vessels at temperatures ranging from 50 to 100 C for times up to three years, and they report mass loss, gas yield and composition, and chemical analysis of the residual solid by methods used in stockpile surveillance. Initial kinetic analysis of the weight of remaining nitrocellulose as measured by liquid chromatography and the loss of nitrate esters by a colorimetric technique gave an activation energy of 27 kcal/mol. However, the reaction is complex due to the different stability of the three nitroester positions, and this complexity required either parallel first-order reactions or an nth-order reaction (n=3.6), which is mathematically equivalent to a Gamma distribution of frequency factors
Burnham, A K; Fried, L E
Multiple temperature kinetic model and gas-kinetic method for hypersonic non-equilibrium flow computations
It is well known that for increasingly rarefied flowfields, the predictions from continuum formulation, such as the Navier-Stokes equations lose accuracy. For the high speed diatomic molecular flow in the transitional regime, the inaccuracies are partially ... Keywords: Gas-kinetic method, Hypersonic and rarefied flows, Multiple temperature kinetic model
Kun Xu; Xin He; Chunpei Cai
Commerce Biofuels Dialogue Series: Outlook for an Commerce Biofuels Dialogue Series: Outlook for an Emerging Global Biofuels Market U.S. Chamber of Commerce Biofuels Dialogue Series: Outlook for an Emerging Global Biofuels Market January 29, 2008 - 10:53am Addthis Remarks as Prepared For Delivery by Secretary Bodman Thank you very much, Bruce, for that kind introduction. My thanks also to Tom Donahue and the leadership of the Chamber for inviting me to be with you today. I was quite pleased to hear that the Chamber was sponsoring this event. As anyone who knows me - or has heard me speak recently - can tell you, the biofuels industry is a favorite topic of mine. In my view, advanced biofuels offer tremendous promise for helping our nation to bring about a new energy future-one that is cleaner, more sustainable, more affordable,
Stability of A-150 plastic ionization chamber response over a ~30 year period
At the NIU Institute for Neutron Therapy at Fermilab, the clinical tissue-equivalent ionization chamber response is measured every treatment day using a cesium source that was configured to match readings obtained at the National Bureau of Standards. Daily measurements are performed in air using the air-to-tissue dose conversion factors given in AAPM Report no. 7. The measured exposure calibration factors have been tabulated and graphed as a function of time from 1978 to present. For A-150 plastic ionization chambers, these factors exhibit a sinusoidal variation with a period of approximately one year and amplitude of {+-} 1%. This variation, attributable to the hygroscopic nature of A-150 plastic, is correlated with the relative humidity of the facility, and is greater than the humidity corrections for gas described in the literature. Our data suggest that chamber calibration should be performed at least weekly to accommodate these variations.
Kroc, Thomas K.; Lennox, Arlene J.; /Fermilab
OSTIblog Posts by Kathy Chambers | OSTI, US Dept of Energy, Office of
Kathy Chambers Kathy Chambers Kathy Chambers's picture Senior STI Specialist, Information International Associates, Inc. Enjoy the benefits of LED lighting Source: http://www.flickr.com/photos/uscapitol/6309229615/in/photostream/ Published on Dec 30, 2013 Every day we are bombarded with advertisements in every form and format telling us that our lives will be improved if we buy a particular product because it will save us money, reduce our work effort, save us energy, or benefit the environment. We are justifiably skeptical because we know from experience that if something sounds too good to be true, usually it is. Light-emitting diode (LED) lighting is one of the exceptions. LEDs benefits are so powerful that they seem too good to be true; however, they actually do save us money, reduce our work effort, save us energy and benefit our environment.
Surface-dependent Coagulation Enzymes: Flow Kinetics of Factor Xa Generation on Live Membranes
The initial surface reactions of the extrinsic coagulation pathway on live cell membranes were examined under flow conditions. Generation of fXa (activated coagulation factor X) was measured on spherical monolayers of epithelial cells with a total surface area of 41-47 cm$^{2}$ expressing TF(tissue factor) at $>25$ fmol/cm$^{2}$. Concentrations of reactants and product were monitored as a function of time with radiolabeled proteins and a chromogenic substrate at resolutions of 2-8 s. At physiological concentrations of fVIIa and fX, the reaction rate was $3.05 \\pm 0.75$ fmol fXa/s/cm$^{2}$, independent of flux, and 10 times slower than that expected for collision-limited reactions. Rates were also independent of surface fVIIa concentrations within the range 0.6-25 fmol/cm$^{2}$. The transit time of fX activated on the reaction chamber was prolonged relative to transit times of nonreacting tracers or preformed fXa. Membrane reactions were modeled using a set of nonlinear kinetic equations and a lagged normal density curve to track the expected surface concentration of reactants for various hypothetical reaction mechanisms. The experimental results were theoretically predicted only when the models used a slow intermediate reaction step, consistent with surface diffusion. These results provide evidence that the transfer of substrate within the membrane is rate-limiting in the kinetic mechanisms leading to initiation of blood coagulation by the tissue factor pathway.
Maria P. McGee; Tom Chou
Physicochemical phenomena of electro-kinetic extraction of inorganic contaminants from kaolinite
Experiments investigating the use of electro-kinetics for removal of inorganic chemicals from kaolinite clay were performed. Kaolinite was homogeneously saturated with a NaCl solution and consolidated to the desired void ratio. Fluid reservoir chambers, a power supply and data acquisition instrument were connected to the consolidated sample. A voltage difference was applied to electrodes at each end of the sample to induce electro-osmotic fluid flow and ionic migration of NaCl. After electro-kinetic treatment the sample was disconnected from the reservoirs, power supply and data acquisition system, then sectioned to allow water content, sodium and chloride concentration, and pH analyses of each section. The data obtained was reduced and prepared in graph form for analysis of results. Energy for electrolysis, total energy expended, and removal efficiency were calculated and graphed for selected experiments. It was concluded that the voltage gradient became non-linear during experimentation, contaminant distribution was dependent on initial concentration, and zones of altered pH and ion removal did correspond in some experiments. Also, the removal efficiency decreased with time during experimentation and increased with intial contaminant concentration. Comparisons to a predictive model suggested that ionic mobility and dissusivity values varied between experiments and the model.
Scott, Travis Brooks
We develop a combined hydro-kinetic approach which incorporates a hydrodynamical expansion of the systems formed in \\textit{A}+\\textit{A} collisions and their dynamical decoupling described by escape probabilities. The method corresponds to a generalized relaxation time ($\\tau_{\\text{rel}}$) approximation for the Boltzmann equation applied to inhomogeneous expanding systems; at small $\\tau_{\\text{rel}}$ it also allows one to catch the viscous effects in hadronic component - hadron-resonance gas. We demonstrate how the approximation of sudden freeze-out can be obtained within this dynamical picture of continuous emission and find that hypersurfaces, corresponding to a sharp freeze-out limit, are momentum dependent. The pion $m_{T}$ spectra are computed in the developed hydro-kinetic model, and compared with those obtained from ideal hydrodynamics with the Cooper-Frye isothermal prescription. Our results indicate that there does not exist a universal freeze-out temperature for pions with different momenta, and support an earlier decoupling of higher $p_{T}$ particles. By performing numerical simulations for various initial conditions and equations of state we identify several characteristic features of the bulk QCD matter evolution preferred in view of the current analysis of heavy ion collisions at RHIC energies.
S. V. Akkelin; Y. Hama; Iu. A. Karpenko; Yu. M. Sinyukov
Small-Chamber Measurements of Chemical-Specific Emission Factors for
Small-Chamber Measurements of Chemical-Specific Emission Factors for Small-Chamber Measurements of Chemical-Specific Emission Factors for Drywall Title Small-Chamber Measurements of Chemical-Specific Emission Factors for Drywall Publication Type Report Year of Publication 2010 Authors Maddalena, Randy L., Marion L. Russell, Moya Melody, and Michael G. Apte Publisher Lawrence Berkeley National Laboratory City Berkeley Abstract Imported drywall installed in U.S. homes is suspected of being a source of odorous and potentially corrosive indoor pollutants. To support an investigation of those building materials by the Consumer Products Safety Commission (CPSC), Lawrence Berkeley National Laboratory (LBNL) measured chemical-specific emission factors for 30 samples of drywall materials. Emission factors are reported for 75 chemicals and 30 different drywall samples encompassing both domestic and imported stock and incorporating natural, synthetic, or mixed gypsum core material. CPSC supplied all drywall materials. First the drywall samples were isolated and conditioned in dedicated chambers, then they were transferred to small chambers where emission testing was performed. Four sampling and analysis methods were utilized to assess (1) volatile organic compounds, (2) low molecular weight carbonyls, (3) volatile sulfur compounds, and (4) reactive sulfur gases. LBNL developed a new method that combines the use of solid phase microextraction (SPME) with small emission chambers to measure the reactive sulfur gases, then extended that technique to measure the full suite of volatile sulfur compounds. The testing procedure and analysis methods are described in detail herein. Emission factors were measured under a single set of controlled environmental conditions. The results are compared graphically for each method and in detailed tables for use in estimating indoor exposure concentrations
Draft General Conformity Determination
I I Draft General Conformity Determination U.S. Department of the Interior Minerals Management Service MMS Cape Wind Energy Project January 2009 Final EIS Appendix I Draft General Conformity Determination Draft General Conformity Determination Cape Wind Energy Project Prepared by Minerals Management Service Herndon, VA November 2008 i TABLE OF CONTENTS 1.0 INTRODUCTION TO THE PROPOSED ACTION............................................................... 1 2.0 GENERAL CONFORMITY REGULATORY BACKGROUND .......................................... 2 2.1 GENERAL CONFORMITY REQUIREMENTS.................................................................... 2 2.2 GENERAL CONFORMITY APPLICABILITY.....................................................................
Philips Color Kinetics | Open Energy Information
Color Kinetics Color Kinetics Jump to: navigation, search Name Philips Color Kinetics Address 3 Burlington Woods Drive, 4th Floor Place Burlington, Massachusetts Zip 01803 Sector Efficiency Product LED lighting systems Website http://www.colorkinetics.com/ Coordinates 42.5005723°, -71.2042619° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.5005723,"lon":-71.2042619,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
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Numerical Simulation of Earth Pressure on Head Chamber of Shield Machine with FEM
Model parameters of conditioned soils in head chamber of shield machine are determined based on tree-axial compression tests in laboratory. The loads acting on tunneling face are estimated according to static earth pressure principle. Based on Duncan-Chang nonlinear elastic constitutive model, the earth pressures on head chamber of shield machine are simulated in different aperture ratio cases for rotating cutterhead of shield machine. Relationship between pressure transportation factor and aperture ratio of shield machine is proposed by using aggression analysis.
Li Shouju; Kang Chengang [State Key Laboratory of structural analysis for industrial equipment, Dalian University of Technology, Dalian 116023 (China); Sun, Wei [School of Mechanical Engineering, Dalian University of Technology, Dalian 116023 (China); Shangguan Zichang [School of Civil and Hydraulic Engineering, Dalian University of Technology, Dalian 116023 (China); Institute of Civil Engineering, Dalian Fishery University, Dalian 116023 (China)
Calibration and performance of a secondary emission chamber as a beam intensity monitor
We report on a study of the behavior of a secondary emission chamber (SEC). We show the dependence of the SEC signal on the charge and velocity of the primary beam for beams of protons, and heavy ions including Helium, Neon, Chlorine and Iron. We fill the SEC with a selection of different gases including Hydrogen, Helium, Nitrogen, Argon, and air, studying the SEC response when it is acting as an ion chamber. We also investigate the behavior of the SEC at intermediate pressures between 10{sup -8} torr and atmospheric pressure. The SEC uses thin conducting foils as the source and collector of electrons in a vacuum chamber. When charged particles traverse the vacuum chamber, they pass through a series of thin conducting foils, alternating anode and cathode. Ionization produced in the cathode foils travels across the intervening gap due to an applied high voltage and is collected on the anode foils. Electron production is very inefficient because most of the ionization in the foils remains trapped within the foil due to the short range of most delta-rays and the work function of the foil. It is this inefficiency that allows the SEC to operate at high dose rates and short pulse duration where the standard ion chambers cannot function reliably. The SEC was placed in the NSRL ion beam to receive a variety of heavy ion beams under different beam conditions. We used these ion beams to study the response of the SEC to different species of heavy ion, comparing with proton beams. We studied the response to beam of different energies, and as a function of different counting rate. We compared the behaviour of the SEC when operating under positive and negative high voltage. The SEC can operate as an ion chamber if it is filled with gas. We measured the response of the SEC when filled with a variety of gases, from Hydrogen to Helium, Nitrogen, Argon and air. The performance of the SEC as an ion chamber is compared with the standard NSRL ion chamber, QC3. By evacuating the SEC and filling it with Nitrogen through an adjustable leak valve, we were able to measure the response of the SEC to beam as a function of gas pressure. Many interesting features of the SEC were revealed in these tests.
Sivertz, M.; Chiang, I-H,; Rusek, A.
Investigation of long drift chambers for a nucleon-decay detector
The use of long drift chambers for a nucleon-decay detector is discussed as a means of achieving a detector with very fine tracking, but with a modest number of readout channels. Strategies for reducing the attenuation of drifting electrons are considered, particularly the necessity of shaping the electric field to reduce the effects of diffusion and of nearby grounded conductors. Measured results are presented for a chamber with 1 cm drift gap and 50 cm maximum drift distance. The measured attenuation is 12%.
Price, L.E.; Dawson, J.; Ayres, D.; Denis, R.S.
Dynamics of neutralizing electrons during the focusing of intense heavy ions beams inside a heavy fusion reactor chamber
beams inside a heavy ion fusion reactor chamber * Agustin F.efficiency of a Heavy Ion Fusion reactor heavily depends on
Lifschitz, Agustin F.; Maynard, Gilles; Vay, Jean-Luc; Lenglet, Andrian
beams inside a heavy ion fusion reactor chamber * Agustin F.of a Heavy Ion Fusion reactor heavily depends on the maximum
??The trumpet has always maintained a central role in the jazz genre. However, throughout the history of chamber music the trumpet was overlooked until the� (more)
Harrison, Kathleen Elizabeth
Model Independent Bounds on Kinetic Mixing
New Abelian vector bosons can kinetically mix with the hypercharge gauge boson of the Standard Model. This letter computes the model independent limits on vector bosons with masses from 1 GeV to 1 TeV. The limits arise from the numerous e{sup +}e{sup -} experiments that have been performed in this energy range and bound the kinetic mixing by {epsilon} {approx}< 0.03 for most of the mass range studied, regardless of any additional interactions that the new vector boson may have.
Hook, Anson; Izaguirre, Eder; Wacker, Jay G.; /SLAC
Consistent description of kinetic equation with triangle anomaly
We provide a consistent description of the kinetic equation with a triangle anomaly which is compatible with the entropy principle of the second law of thermodynamics and the charge/energy-momentum conservation equations. In general an anomalous source term is necessary to ensure that the equations for the charge and energy-momentum conservation are satisfied and that the correction terms of distribution functions are compatible to these equations. The constraining equations from the entropy principle are derived for the anomaly-induced leading order corrections to the particle distribution functions. The correction terms can be determined for the minimum number of unknown coefficients in one charge and two charge cases by solving the constraining equations.
Pu Shi; Gao Jianhua; Wang Qun [Interdisciplinary Center for Theoretical Study and Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China)
A Detailed Chemical Kinetic Analysis of Low Temperature Non-Sooting Diesel Combustion
We have developed a model of the diesel fuel injection process for application to analysis of low temperature non-sooting combustion. The model uses a simplified mixing correlation and detailed chemical kinetics, and analyzes a parcel of fuel as it moves along the fuel jet, from injection into evaporation and ignition. The model predicts chemical composition and soot precursors, and is applied at conditions that result in low temperature non-sooting combustion. Production of soot precursors is the first step toward production of soot, and modeling precursor production is expected to give insight into the overall evolution of soot inside the engine. The results of the analysis show that the model has been successful in describing many of the observed characteristics of low temperature combustion. The model predicts results that are qualitatively similar to those obtained for soot formation experiments at conditions in which the EGR rate is increased from zero to very high values as the fueling rate is kept constant. The model also describes the two paths to achieve non-sooting combustion. The first is smokeless rich combustion and the second is modulated kinetics (MK). The importance of the temperature after ignition and the equivalence ratio at the time of ignition is demonstrated, as these parameters can be used to collapse onto a single line all the results for soot precursors for multiple fueling rates. A parametric analysis indicates that precursor formation increases considerably as the gas temperature in the combustion chamber and the characteristic mixing time are increased. The model provides a chemical kinetic description of low temperature diesel combustion that improves the understanding of this clean and efficient regime of operation.
Aceves, S M; Flowers, D L
Uncertain generalized aggregation operators
The aim of this paper is to extend the generalized ordered weighted averaging operator and provide a new class of operators called the uncertain generalized ordered weighted averaging (UGOWA) operator. It provides a very general formulation that includes ... Keywords: Aggregation, Decision making, Generalized mean, OWA operator, Operator weights
Li-Gang Zhou; Hua-You Chen; Jos� M. Merig�; Anna M. Gil-Lafuente
Ocean Circulation Kinetic Energy: Reservoirs, Sources,
. The coupling of the generation of different energy forms in the dynamics (in either balanced or wave motions are almost nonexistent in the ocean. www.annualreviews.org · Ocean Circulation Kinetic Energy 255 Annu.Rev.Fluid processes? Are the seemingly different dynamical ranges coupled? 2. THE OCEANIC ENERGY BUDGET We begin
Ferrari, Raffaele
Thermodynamics and Kinetics of a Brownian Motor
Thermodynamics and Kinetics of a Brownian Motor R. Dean Astumian Nonequilibrium fluctuations particle separation and the design of molecular motors and pumps. A small particle in a liquid is subject in conjunction with an- isotropy to drive a motor in the context of a "ratchet and pawl" device shrunk to micro
Linke, Heiner
KINETICS, STABILITY, AND CONTROL. A Selected Bibliography
References to 529 articles on nuclear reactor control, kinetics, and stability published before autumn 1962 are included. Emphasis is on calculations and theory since the references serve as an aid in analyzing the dynamic behavior of SNAP reactor systems. (D.C.W.)
Johnson, R.L.
Radiation from Kinetic Poynting Flux Acceleration
We derive analytic formulas for the power output and critical frequency of radiation by electrons accelerated by relativistic kinetic Poynting flux, and validate these results with Particle-In-Cell plasma simulations. We find that the in-situ radiation power output and critical frequency are much below those predicted by the classical synchrotron formulae. We discuss potential astrophysical applications of these results.
Edison Liang; Koichi Noguchi
In situ reduction and evaluation of anode supported single chamber solid oxide fuel cells
cracking (reaction VII) CH4 + H2O CO + 3H2 steam reforming (reaction VIII) CH4 + CO2 2CO + 2H2 dry.05.118 #12;Abstract Single chamber anode-supported fuel cells are investigated under several methane analyses of anode reduction are performed at 700°C. Carbon deposition is observed under diluted methane
Combustion chamber for gas turbines and the like having a fluidized burner bed
A combustion chamber with a fluidized burner bed preferably for gas turbines is described. It contains means for controlling the supply of fuel, combustion air and a cooling medium for the fluidized bed to maintain a predetermined proportional relationship between combustion air and cooling air under varying load conditions.
Harboe, H.
Nested reactor chamber and operation for Hg-196 isotope separation process
The present invention is directed to an apparatus for use in .sup.196 Hg separation and its method of operation. Specifically, the present invention is directed to a nested reactor chamber useful for .sup.196 Hg isotope separation reactions avoiding the photon starved condition commonly encountered in coaxial reactor systems.
Grossman, Mark W. (Belmont, MA)
Neutronics Assessment of Blanket Options for the HAPL Laser Inertial Fusion Energy Chamber
on lasers, direct drive targets and a dry wall chamber [1]. A primary focus is the development of a tungsten-armored-explosion. Only a thin region of the armor (10-100 µm) will experience the highly cyclic x-ray and ion energy deposition transients. The FW structure behind the armor as well as the blanket will operate under quasi
Report on Fission Time Projection Chamber M3FT-12IN0210052
The Time Projection Chamber is a collaborative effort to implement an innovative approach and deliver unprecedented fission measurements to DOE programs. This 4?-detector system will provide unrivaled 3-D data about the fission process. Shown here is a half populated TPC (2?) at the LLNL TPC laboratory as it undergoes testing before being shipped to LANSCE for beam experiments.
James K. Jewell
LASER IFE DIRECT DRIVE CHAMBER CONCEPTS WITH MAGNETIC INTERVENTION A. R. Raffray1
, Washington, DC 20375, firstname.lastname@example.com 3 Naval Research Laboratory, Washington, DC 20375, john, Washington, D.C. REFERENCES 1. J. SETHIAN, et al., "An Overview of the Development of the First Wall. RAFFRAY and the HAPL Team, "Threats, Design Limits and Design Windows for Laser IFE Dry Wall Chambers," J
Pulse mode readout techniques for use with non-gridded industrial ionization chambers
Highly sensitive readout technique for precision long-term radiation measurements has been developed and tested in the Radiation Control Department at Jefferson Lab. The new electronics design is used to retrieve ionization data in a pulse mode. The dedicated data acquisition system works with M=Audio Audiophile 192 High-Definition 24-bit/192 kHz audio cards, taking data in continuous waveform recording mode. The on-line data processing algorithms extract signals of the ionization events from the data flow and measure the ionization value for each event. Two different ion chambers are evaluated. The first is a Reuter-Stokes Argon-filled (at 25 atm) High Pressure Ionization Chamber (HPIC), commonly used as a detector part in many GE Reuter-Stokes instruments of the RSS series. The second is a VacuTec Model 70181, 5 atm Xenon-filled ionization chamber. Results for both chambers indicate that the techniques allow using industrial ICs for high sensitivity and precision long-term radiation measurements, while at the same time providing information about spectral characteristics of the radiation fields.
Popov, Vladimir E. [JLAB; Degtiarenko, Pavel V. [JLAB
A Diffusion Cloud Chamber Study of Very Slow Mesons. II. Beta Decay of the Muon
The spectrum of electrons arising from the decay of the negative mu meson has been determined. The muons are arrested in the gas of a high pressure hydrogen filled diffusion cloud chamber. The momenta of the decay electrons are determined from their curvature in a magnetic field of 7750 gauss. The spectrum of 415 electrons has been analyzed according to the theory of Michel.
Lederman, L. M.; Sargent, C. P.; Rinehart, M.; Rogers, K.
Fault Detection and Isolation of a Cryogenic Rocket Engine Combustion Chamber Using a Parity Space Approach
his paper presents a parity space (PS) approach for fault detection and isolation (FDI) of a cryogenic rocket engine combustion chamber. Nominal and non-nominal simulation data for three engine set points have been provided. The PS approach uses three ... Keywords: Fault Detection, Fault Isolation, Fault Diagnosis, Parity Space, Rocket Engine
Paul van Gelder; Andr� Bos
Thermodynamics and Kinetics of a Go Proteinlike Heteropolymer Model with Two-State Folding Characteristics
We present results of Monte Carlo computer simulations of a coarse-grained hydrophobic-polar Go-like heteropolymer model and discuss thermodynamic properties and kinetics of an exemplified heteropolymer, exhibiting two-state folding behavior. It turns out that general, characteristic folding features of realistic proteins with a single free-energy barrier can also be observed in this simplified model, where the folding transition is primarily driven by the hydrophobic force.
Anna Kallias; Michael Bachmann; Wolfhard Janke
Analytical solution of the kinetic equation for a uniform plasma in a magnetic field
The kinetic equation for a single-component uniform plasma in a magnetic field is analytically solved by the moment method. The linear system of ordinary differential equations for the moments is decomposed into subsystems of lower dimensions by a geometric method. The eigensystem of each subsystem shows that parallel moments decay monotonically, but perpendicular lth harmonic moments decay while oscillating with the l,l-2,...,-th harmonics of gyrofrequency. A generalization to a multicomponent plasma is discussed.
Ji, Jeong-Young; Held, Eric D. [Department of Physics, Utah State University, Logan, Utah 84322 (United States)
Chemical Kinetic Modeling of Hydrogen Combustion Limits
A detailed chemical kinetic model is used to explore the flammability and detonability of hydrogen mixtures. In the case of flammability, a detailed chemical kinetic mechanism for hydrogen is coupled to the CHEMKIN Premix code to compute premixed, laminar flame speeds. The detailed chemical kinetic model reproduces flame speeds in the literature over a range of equivalence ratios, pressures and reactant temperatures. A series of calculation were performed to assess the key parameters determining the flammability of hydrogen mixtures. Increased reactant temperature was found to greatly increase the flame speed and the flammability of the mixture. The effect of added diluents was assessed. Addition of water and carbon dioxide were found to reduce the flame speed and thus the flammability of a hydrogen mixture approximately equally well and much more than the addition of nitrogen. The detailed chemical kinetic model was used to explore the detonability of hydrogen mixtures. A Zeldovich-von Neumann-Doring (ZND) detonation model coupled with detailed chemical kinetics was used to model the detonation. The effectiveness on different diluents was assessed in reducing the detonability of a hydrogen mixture. Carbon dioxide was found to be most effective in reducing the detonability followed by water and nitrogen. The chemical action of chemical inhibitors on reducing the flammability of hydrogen mixtures is discussed. Bromine and organophosphorus inhibitors act through catalytic cycles that recombine H and OH radicals in the flame. The reduction in H and OH radicals reduces chain branching in the flame through the H + O{sub 2} = OH + O chain branching reaction. The reduction in chain branching and radical production reduces the flame speed and thus the flammability of the hydrogen mixture.
Pitz, W J; Westbrook, C K
Isothermal Ice Crystallization Kinetics in the Gas-Diffusion...
Isothermal Ice Crystallization Kinetics in the Gas-Diffusion Layer of a Proton-Exchange-Membrane Fuel Cell Title Isothermal Ice Crystallization Kinetics in the Gas-Diffusion Layer...
The Vertical Partition of Oceanic Horizontal Kinetic Energy
To produce an interpretation of the surface kinetic energy as measured by altimeters, a survey is made of the vertical structure of kinetic energy profiles in a large number of globally distributed long current meter records. Although the data ...
Carl Wunsch
Evaluating Mesoscale NWP Models Using Kinetic Energy Spectra
Kinetic energy spectra derived from observations in the free atmosphere possess a wavenumber dependence of k?3 for large scales, characteristic of 2D turbulence, and transition to a k?5/3 dependence in the mesoscale. Kinetic energy spectra ...
William C. Skamarock
Fabrication of The Multi-PCR Chamber With Inner Heat-Sink Materials Using a Micro-Blaster Etching Technique
In this paper, we propose a new design for a PCR (Polymerase Chain Reaction) chamber with a temperature sensor under a top glass wafer and heaters on the bottom glass wafer. These chamber sensors are thermally isolated from the heater. The multi PCR ...
Hyoung-Jin Park; Duk-Soo Eun; Dae-Young Kong; Seong-Jin Kong; Seong-Ho Kong; Jong-Hyun Lee
LS-266 LS-266 OPTIMIZATION OF FOUR-BUTTON BEAM POSITION MONITOR CONFIGURATION FOR SMALL-GAP VACUUM CHAMBERS S. H. Kim March 27, 1998 Summary - Induced charges on a four-button beam position monitor (BPM) system attached on a beam chamber of narrow rectangular cross sections are calculated as a 2-D electrostatic problem of image charges. The calculation shows that for a narrow chamber of width/height (2w/2h) >> 1, over 90% of the induced charges are distributed within a distance of 2h from the charged beam position in the direction of the chamber width. Therefore, a four-button system with a button diameter of (2 ~ 2.5)h and no button offset from the beam position is the most efficient configuration. The four-button BPMs used for 8-mm and 5-mm chambers in the APS have relatively low sensitivities because the button locations are outside
Kinetic Controls on Cu and Pb Sorption by Ferrihydrite
nd ed.; Cambridge University Press: New York, 1993. (51) Sparks, D. L. Kinetics of Soil Chemical Processes; Academic Press: New York, 1989. (52) Espenson, J. H. Chemical Kinetics and Reaction Mechanisms, 2Kinetic Controls on Cu and Pb Sorption by Ferrihydrite A N D R E A S C . S C H E I N O
Sparks, Donald L.
Kinetic and stationary point-set embeddability for plane graphs
We investigate a kinetic version of point-set embeddability. Given a plane graph G(V,E) where |V|=n, and a set P of n moving points where the trajectory of each point is an algebraic function of constant ... Keywords: kinetic algorithm, kinetic graph drawing, plane graph, point-set embeddability
Zahed Rahmati; Sue H. Whitesides; Valerie King
Asphalt Oxidation Kinetics and Pavement Oxidation Modeling
Most paved roads in the United States are surfaced with asphalt. These asphalt pavements suffer from fatigue cracking and thermal cracking, aggravated by the oxidation and hardening of asphalt. This negative impact of asphalt oxidation on pavement performance has not been considered adequately in pavement design. Part of the reason is that the process of asphalt oxidation in pavement is not well understood. This work focused on understanding the asphalt oxidation kinetics and on developing pavement oxidation model that predicts asphalt oxidation and hardening in pavement under environmental conditions. A number of asphalts were studied in laboratory condition. Based on kinetics data, a fast-rate ? constant-rate asphalt oxidation kinetics model was developed to describe the early nonlinear fast-rate aging period and the later constant-rate period of asphalt oxidation. Furthermore, reaction kinetics parameters for the fast-rate and constant-rate reactions were empirically correlated, leading to a simplified model. And the experimental effort and time to obtain these kinetics parameters were significantly reduced. Furthermore, to investigate the mechanism of asphalt oxidation, two antioxidants were studied on their effectiveness. Asphalt oxidation was not significantly affected. It was found that evaluation of antioxidant effectiveness based on viscosity only is not reliable. The asphalt oxidation kinetics model was incorporated into the pavement oxidation model that predicts asphalt oxidation in pavement. The pavement oxidation model mimics the oxidation process of asphalt in real mixture at pavement temperatures. A new parameter, diffusion depth, defined the oxygen diffusion region in the mastic. A field calibration factor accounted for the factors not considered in the model such as the effect of small aggregate particles on oxygen diffusion. Carbonyl area and viscosity of binders recovered from field cores of three pavements in Texas were measured and were used for model calibration and validation. Results demonstrated that the proposed model estimates carbonyl growth over time in pavement, layer-by-layer, quite well. Finally, this work can be useful for incorporating asphalt oxidation into a pavement design method that can predict pavement performance with time and for making strategic decisions such as optimal time for maintenance treatments.
Jin, Xin
Neutrino--deuterium reactions in the 7-foot bubble chamber. [Strangeness, CVC theory, V-A theory
Recent results are reported from the analysis of 569,000 ..nu.. pictures taken in the BNL 7-ft bubble chamber filled with D/sub 2/ (and an additional 204,000 pictures in H/sub 2/). The statistics of current analysis include 648 quasielastic ..nu../sub ..mu../ d ..-->.. ..mu../sup -/pp/sub s/ events and 25 events with visible strangeness present. Using the quasielastic events in the framework of the conventional V-A theory, the values M/sub V/ = 0.87 +- 0.09 GeV and M/sub A/ = 1.03 +- 0.19 GeV are found. The value is in good agreement with the CVC prediction of M/sub V/ = 0.84 GeV. With the fixed value of M/sub V/ = 0.84 GeV, a one-parameter fit yields M/sub A/ = 1.08 +- 0.08 GeV. Also 8 events are found in the exclusive channel ..nu..n ..-->.. ..mu../sup -/K/sup +/..lambda.. in agreement with a theoretical calculation using the generalized Born approximation. 30 references.
Cnops, A M; Connolly, P L; Kahn, S A; Kirk, H G; Murtagh, M J; Palmer, R B; Samios, N P; Tanaka, M
General Dynamics, Electric Boat
General Dynamics, Electric Boat. NVLAP Lab Code: 100560-0. Address and Contact Information: 75 Eastern Point Road ...
Analysis on kinetic chemotaxis models using a functional analytic approach Analysis on kinetic chemotaxis models using a
that are applicable at the molecular level. Copyright # 2004 John Wiley & Sons, Ltd. KEYWORDS: kinetic stability of that system are undergoing constant change. This chemical example of replicator kinetic stability is akin in circumstance may dramatically affect the kinetic stability of physical, chemical and biological, systems. So
Hille, Sander
React. Kinet.Catal.Lett., Vol.9, No. 4,377-381 (1978) WHAT IS ESSENTIAL TO EXOTIC KINETIC BEHAVIOR?
6= 10'. I = 1 I=I 378 #12;TOTH: EXOTIC KINETIC BEHAVIOR? COROLLARIES Immediate application). REFERENCES 1. M. Feinberg: Mathamatical Aspects of Mass Action Kinetics. Chapter 1 of Chemical Reactor Theory-London-New York 1972. 3. J. T6th, P. ~rdi: Models, Problems and Applications of Formal Reaction Kinetics (in
Tóth, János
Auxiliary power supply with kinetic energy storage
Alternating current is supplied to an auxiliary load on a from a power supply comprised of a dc-energized inverter and a synchronous machine coupled to the inverter. The inverter supplies the alternating current requirements of the load up to the normal steady state load current magnitude. The synchronous machine stores kinetic energy when the load current load does not exceed its normal steady state magnitude, and converts kinetic energy into electrical energy to supply the load current requirements in excess of its normal steady-state load magnitude and to supply load current whenever the dc source inverter connection is interrupted. Frequency and amplitude of load voltage are regulated by operator commands through control apparatus coupled to the inverter and the synchronous machine.
Plunkett, A.B.; Turnbull, F.G.
ET Kinetics of Bifunctional Redox Protein Maquettes
Kinetics of Bifunctional Redox Protein Maquettes Kinetics of Bifunctional Redox Protein Maquettes Mitchell W. Mutz, James F. Wishart and George L. McLendon Adv. Chem Ser. 254, Ch. 10, pp. 145-159 Abstract: We prepared three bifunctional redox protein maquettes based on 12-, 16-, and 20-mer three-helix bundles. In each case, the helix was capped with a Co(III) tris-bipyridyl electron acceptor and also functionalized with a C-terminal viologen (1-ethyl-1'-ethyl-4,4'-bipyridinium) donor. Electron transfer (ET) was initiated by pulse radiolysis and flash photolysis and followed spectrometrically to determined average, concentration-independent, first-order rates for the 16-mer and 20-mer maquettes. For the 16-mer bundle, the alpha-helical content was adjusted by the addition of urea or trifluoroethanol to solutions containing the metalloprotein. This
A new class of accelerated kinetic Monte Carlo algorithms
Kinetic (aka dynamic) Monte Carlo (KMC) is a powerful method for numerical simulations of time dependent evolution applied in a wide range of contexts including biology, chemistry, physics, nuclear sciences, financial engineering, etc. Generally, in a KMC the time evolution takes place one event at a time, where the sequence of events and the time intervals between them are selected (or sampled) using random numbers. While details of the method implementation vary depending on the model and context, there exist certain common issues that limit KMC applicability in almost all applications. Among such is the notorious 'flicker problem' where the same states of the systems are repeatedly visited but otherwise no essential evolution is observed. In its simplest form the flicker problem arises when two states are connected to each other by transitions whose rates far exceed the rates of all other transitions out of the same two states. In such cases, the model will endlessly hop between the two states otherwise producing no meaningful evolution. In most situation of practical interest, the trapping cluster includes more than two states making the flicker somewhat more difficult to detect and to deal with. Several methods have been proposed to overcome or mitigate the flicker problem, exactly [1-3] or approximately [4,5]. Of the exact methods, the one proposed by Novotny [1] is perhaps most relevant to our research. Novotny formulates the problem of escaping from a trapping cluster as a Markov system with absorbing states. Given an initial state inside the cluster, it is in principle possible to solve the Master Equation for the time dependent probabilities to find the walker in a given state (transient or absorbing) of the cluster at any time in the future. Novotny then proceeds to demonstrate implementation of his general method to trapping clusters containing the initial state plus one or two transient states and all of their absorbing states. Similar methods have been subsequently proposed in [refs] but applied in a different context. The most serious deficiency of the earlier methods is that size of the trapping cluster size is fixed and often too small to bring substantial simulation speedup. Furthermore, the overhead associated with solving for the probability distribution on the trapping cluster sometimes makes such simulations less efficient than the standard KMC. Here we report on a general and exact accelerated kinetic Monte Carlo algorithm generally applicable to arbitrary Markov models1. Two different implementations are attempted both based on incremental expansion of trapping sub-set of Markov states: (1) numerical solution of the Master Equation with absorbing states and (2) incremental graph reduction followed by randomization. Of the two implementations, the 2nd one performs better allowing, for the first time, to overcome trapping basins spanning several million Markov states. The new method is used for simulations of anomalous diffusion on a 2D substrate and of the kinetics of diffusive 1st order phase transformations in binary alloys. Depending on temperature and (alloy) super-saturation conditions, speedups of 3 to 7 orders of magnitude are demonstrated, with no compromise of simulation accuracy.
Bulatov, V V; Oppelstrup, T; Athenes, M
An analysis of errors in measurement yields new insight into the penetration of quantum particles into classically forbidden regions. In addition to �physical� values, realistic measurements yield �unphysical � values which, we show, can form a consistent pattern. An experiment to isolate a particle in a classically forbidden region obtains negative values for its kinetic energy. These values realize the concept of a weak value, discussed in previous works. 0
Yakir Aharonov; Sandu Popescu; Daniel Rohrlich; Lev Vaidman
Rhodopsin kinetics in the cat retina
The bleaching and regeneration of rhodopsin in the living cat retina was studied by means of fundus reflectometry. Bleaching was effected by continuous light exposures of 1 min or 20 min, and the changes in retinal absorbance were measured at 29 wavelengths. For all of the conditions studied (fractional bleaches of from 65 to 100%), the regeneration of rhodopsin to its prebleach levels required greater than 60 min in darkness. After the 1-min exposures, the difference spectra recorded during the first 10 min of dark adaptation were dominated by photoproduct absorption, and rhodopsin regeneration kinetics were obscured by these intermediate processes. Extending the bleaching duration to 20 min gave the products of photolysis an opportunity to dissipate, and it was possible to follow the regenerative process over its full time-course. It was not possible, however, to fit these data with the simple exponential function predicted by first-order reaction kinetics. Other possible mechanisms were considered and are presented in the text. Nevertheless, the kinetics of regeneration compared favorably with the temporal changes in log sensitivity determined electrophysiologically by other investigators. Based on the bleaching curve for cat rhodopsin, the photosensitivity was determined and found to approximate closely the value obtained for human rhodopsin; i.e., the energy Ec required to bleach 1-e-1 of the available rhodopsin was 7.09 log scotopic troland-seconds (corrected for the optics of the cat eye), as compared with approximately 7.0 in man.
Ripps, H.; Mehaffey, L.; Siegel, I.M.
DNA hybridization kinetics: zippering, internal displacement and sequence dependence
While the thermodynamics of DNA hybridization is well understood, much less is known about the kinetics of this classic system. Filling this gap in our understanding has new urgency because DNA nanotechnology often depends critically on binding rates. Here we use a coarse-grained model to explore the hybridization kinetics of DNA oligomers, finding that strand association proceeds through a complex set of intermediate states. Successful binding events start with the formation of a few metastable base-pairing interactions, followed by zippering of the remaining bonds. However, despite reasonably strong interstrand interactions, initial contacts frequently fail to lead to zippering because the typical configurations in which they form differ from typical states of similar enthalpy in the double-stranded equilibrium ensemble. Therefore, if the association process is analyzed on the base-pair (secondary structure) level, it shows non-Markovian behavior. Initial contacts must be stabilized by two or three base pairs before full zippering is likely, resulting in negative effective activation enthalpies. Non-Arrhenius behavior is observed as the number of base pairs in the effective transition state increases with temperature. In addition, we find that alternative pathways involving misbonds can increase association rates. For repetitive sequences, misaligned duplexes frequently rearrange to form fully paired duplexes by two distinct processes which we label `pseudoknot' and `inchworm' internal displacement. We show how the above processes can explain why experimentally observed association rates of GC-rich oligomers are higher than rates of AT-rich equivalents. More generally, we argue that association rates can be modulated by sequence choice.
Thomas E. Ouldridge; Petr �ulc; Flavio Romano; Jonathan P. K. Doye; Ard A. Louis
Gas Kinetic Study of Magnetic Field Effects on Plasma Plumes
Plasma flow physics in magnetic nozzles must be clearly understood for optimal design of plasma propulsion devices. Toward that end, in this thesis we: i) perform an extensive literature survey of magnetic nozzle physics, ii) assess the validity of magnetohydrodynamics for studying magnetic nozzle physics, and iii) illustrate the effects of the Hall term in simple flows as well as in magnetic nozzle configurations through numerical experiments with the Magneto-Gas Kinetic Method (MGKM). The crucial steps necessary for thrust generation in magnetic nozzles are energy conversion, plasma detachment, and momentum transfer. These three physical phenomena must be understood to optimize magnetic nozzle design. The operating dimensionless parameter ranges of six prominent experiments are considered and the corresponding mechanisms are discussed. An order of magnitude analysis of the governing equations reveal: i) most magnetic nozzles under consideration operate at the edge of the continuum regime rendering continuum-based description and computation valid; ii) in the context of MHD framework, the generalized Ohm�s law must be used to capture all of the relevant physics. This work also continues the development of the Magneto Gas Kinetic Method (MGKM) computational tool. Validation of the solver is performed in shock-tube and Hartmann channel flows in the Hall physics regime. Comparison with theory and available data is made whenever possible. Novel numerical experiments of magnetic nozzle plasma jets in the Hall regime are performed, confirming the theoretically predicted azimuthal rotation of the plasma jet due to Hall physics. The primary conclusion from this work is that the addition of the Hall effect generates helical structures in magnetic nozzle plasma flows. Preliminary results are encouraging for future magnetic nozzle studies and further challenges are identified.
Ebersohn, Frans 1987-
Model of High Current Breakdown from Cathode Field Emission in Aged Wire Chambers
Observing single electron pulses provides insight into the mechanism that leads to sudden high current jumps (breakdown) in aged wire chambers. This single electron activity is found to be consistent with the Fowler-Nordheim equation for field emission of electrons from a cathode surface in a high electric field. The high electric field arises from the positive ion buildup on a very thin insulating layer on the cathode surface. A model is presented to explain the transient behavior of single electron pulses in response to abrupt changes in chamber ionization, as well as the steady state rate during a long term aging run. The model is based on properties of the insulating layer (dielectric constant, conductivity, and hole-mobility) as well as the Fowler-Nordheim equation.
Boyarski, A
Processing of O.F.E. copper beam chambers for PEP-II high energy ring
Using laboratory scale and full size PEP-II vacuum chambers, chemical cleaning, glow discharge and thermal process effects were evaluated using surface analysis by x-ray photoelectron spectroscopy (XPS). These processes were optimized to reduce surface carbon and thereby minimize photodesorption gas loads. The relation of surface carbon to ion dose was investigated and compared for pure argon, 5% oxygen in argon, and pure hydrogen plasmas. Argon incorporation was noted only when the copper was oxidized in the mixed gas. Surfaces, stable in ambient atmosphere, were obtained having surface carbon values less than 10%. These optimized recipes will be used in processing copper vacuum chambers for the PEP-II B-Factory.
Hoyt, E.; Hoyt, M.; Kirby, R.; Perkins, C.; Wright, D.; Farvid, A.
The stainless steel vacuum chambers of the 248m accumulator ring of Spallation Neutron Source (SNS) are coated with {approx} 100 nm of titanium nitride (TiN) to reduce the secondary electron yield. The coating is produced by DC magnetron sputtering using a long cathode imbedded with permanent magnets. The outgassing rates of several SNS half-cell chambers were measured with and without TiN coating, and before and after in-situ bake. One potential benefit of a TiN coating is to serve as hydrogen permeation barrier that reduces the ultimate outgassing rate. By varying the coating parameters, films of different surface roughness were produced and analyzed by Auger electron spectroscopy, scanning electron microscopy and atomic force microscopy to illustrate the dependence of the outgassing on the film structure.
Apparatus for monitoring tritium in tritium-contaminating environments using a modified Kanne chamber
A conventional Kanne tritium monitor has been redesigned to reduce its sensitivity to such contaminants as tritiated water vapor and tritiated oil. The high voltage electrode has been replaced by a wire cylinder and the collector electrode has been reduced in diameter. The area sensitive to contamination has thereby been reduced by about a factor of forty while the overall apparatus sensitivity and operation has not been affected. The design allows for in situ decontamination of the chambers, if necessary.
Anderson, D.F.
Challenges Surrounding the Injection and Arrival of Targets at LIFE Fusion Chamber Center
IFE target designers must consider several engineering requirements in addition to the physics requirements for successful target implosion. These considerations include low target cost, high manufacturing throughput, the ability of the target to survive the injection into the fusion chamber and arrive in a condition and physical position consistent with proper laser-target interaction and ease of post-implosion debris removal. This article briefly describes these considerations for the Laser Inertial Fusion-based Energy (LIFE) targets currently being designed.
Miles, R; Spaeth, M; Manes, K; Amendt, P; Tabak, M; Bond, T; Kucheyev, S; Latkowski, J; Loosmore, G; Bliss, E; Baker, K; Bhandarkar, S; Petzoldt, R; Alexander, N; Tillack, M; Holdener, D
Fusion Engineering and Design 42 (1998) 537548 Chamber technology concepts for inertial fusion energy--three
to 650°C and has a low enough vapor pressure. Li and Li17Pb83 would also work but must be 1.5 m thick and increased pumping power features required by use of Li or Li17Pb83 suggest Flibe might be the lowest cost to a large variety of chamber design concepts for inertial fusion energy (IFE). Refs. [18] provide
Apparatus for monitoring tritium in tritium contaminating environments using a modified Kanne chamber
Anderson, David F. (Los Alamos, NM)
PRE-SW Aging Chamber Report Tool (ACRT) Version 6.0, Beta
Performance of Glass Resistive Plate Chambers for a high granularity semi-digital calorimeter
A new design of highly granular hadronic calorimeter using Glass Resistive Plate Chambers (GRPCs) with embedded electronics has been proposed for the future International Linear Collider (ILC) experiments. It features a 2-bit threshold semi-digital read-out. Several GRPC prototypes with their electronics have been successfully built and tested in pion beams. The design of these detectors is presented along with the test results on efficiency, pad multiplicity, stability and reproducibility.
Bedjidian, M; Boudry, V; Combaret, C; Decotigny, D; Gil, E Cortina; de la Taille, C; Dellanegra, R; Gapienko, V A; Grenier, G; Jauffret, C; Kieffer, R; Fouz, M -C; Han, R; Laktineh, I; Lumb, N; Manai, K; Mannai, S; Mathez, H; Mirabito, L; Pelayo, J Puerta; Ruan, M; Schirra, F; Seguin-Moreau, N; Tromeur, W; Tytgat, M; Donckt, M Vander; Zaganidis, N
Inertial confinement fusion reaction chamber and power conversion system study. Final report
This report summarizes the results of the second year of a two-year study on the design and evaluation of the Cascade concept as a commercial inertial confinement fusion (ICF) reactor. We developed a reactor design based on the Cascade reaction chamber concept that would be competitive in terms of both capital and operating costs, safe and environmentally acceptable in terms of hazard to the public, occupational exposure and radioactive waste production, and highly efficient. The Cascade reaction chamber is a double-cone-shaped rotating drum. The granulated solid blanket materials inside the rotating chamber are held against the walls by centrifugal force. The fusion energy is captured in a blanket of solid carbon, BeO, and LiAlO/sub 2/ granules. These granules are circulated to the primary side of a ceramic heat exchanger. Primary-side granule temperatures range from 1285 K at the LiAlO/sub 2/ granule heat exchanger outlet to 1600 K at the carbon granule heat exchanger inlet. The secondary side consists of a closed-cycle gas turbine power conversion system with helium working fluid, operating at 1300 K peak outlet temperature and achieving a thermal power conversion efficiency of 55%. The net plant efficiency is 49%. The reference design is a plant producing 1500 MW of D-T fusion power and delivering 815 MW of electrical power for sale to the utility grid. 88 refs., 44 figs., 47 tabs.
Maya, I.; Schultz, K.R.; Bourque, R.F.; Cheng, E.T.; Creedon, R.L.; Norman, J.H.; Price, R.J.; Porter, J.; Schuster, H.L.; Simnad, M.J.
Interpretation of Secondary Organic Aerosol Formation from Diesel Exhaust Photooxidation in an Environmental Chamber
Secondary organic aerosol (SOA) formation from diesel exhaust in a smog chamber was investigated. Particle volume measurement based on mobility diameter is shown to underestimate SOA formation from diesel exhaust due to the external void space of agglomerate particles, in which case mass-based measurement technique is necessary. Rapid determination of particle effective density as a function of particle mass was performed by an Aerosol Particle Mass analyzer � Scanning Mobility Particle Sizer (APM-SMPS) to obtain particle mass concentration and fractal dimension. Continuous aging of aerosol was observed in terms of atomic ratio (O/C), from 0.05 to 0.25 in 12 hours, underscoring the importance of multi-generational oxidation of low-volatile organic vapors emitted from diesel engine as the significant source of oxygenated SOA. Experimental conditions possibly have strong impacts on physical evolution of diesel particulates in a smog chamber. Higher particle effective densities were observed when raw exhaust was injected into a full bag as opposed to filling a bag with diluted exhaust using an ejector diluter. When longer transfer line was used for injecting diesel exhaust into the smog chamber, rapid particle coagulation was observed, leading to increasing particle volume concentration in dark while its mass concentration is decreasing.
Nakao, Shunsuke; Shrivastava, ManishKumar B.; Nguyen, Anh; Jung, Hee-Jung; Cocker, David R.
Pedestal Fueling Simulations with a Coupled Kinetic-kinetic Plasma-neutral Transport Code
A Monte Carlo neutral transport routine, based on DEGAS2, has been coupled to the guiding center ion-electron-neutral neoclassical PIC code XGC0 to provide a realistic treatment of neutral atoms and molecules in the tokamak edge plasma. The DEGAS2 routine allows detailed atomic physics and plasma-material interaction processes to be incorporated into these simulations. The spatial pro le of the neutral particle source used in the DEGAS2 routine is determined from the uxes of XGC0 ions to the material surfaces. The kinetic-kinetic plasma-neutral transport capability is demonstrated with example pedestal fueling simulations.
D.P. Stotler, C.S. Chang, S.H. Ku, J. Lang and G.Y. Park
Energy Conservation Tests of a Coupled Kinetic-kinetic Plasma-neutral Transport Code
D.P. Stotler, C.S. Chang, S.H. Ku, J. Lang and G. Park
DOE General Competencies
Energy.gov (U.S. Department of Energy (DOE))
The DOE General Competencies are the personal and professional attributes that are critical to successful performance.� A competency model is a collection of competencies that together define...
General Employee Radiological Training
DOE HANDBOOK GENERAL EMPLOYEE RADIOLOGICAL TRAINING U.S. Department of Energy AREA TRNG Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution...
1998 EMC: General Information
For information regarding the DRC, please contact Emmanuel Crabb�, DRC General Meeting Chair, IBM SRDC, MS-E40, Building 630, 1580 Route 52,�...
Photon Generalized Parton Distributions
We present a calculation of the generalized parton distributions of the photon using overlaps of photon light-front wave functions.
Asmita Mukherjee; Sreeraj Nair
Mukherjee, Asmita
Effect of Grain Size on Uranium(VI) Surface Complexation Kinetics and Adsorption Additivity
Laboratory experiments were performed to investigate the contribution of variable grain sizes to uranium adsorption/desorption in a sediment collected from the US DOE Hanford site. The sediment was wet-sieved into four size fractions: coarse sand (1-2 mm), medium sand (0.2-1 mm), fine sand (0.05-0.2 mm), and clay/silt fraction (< 0.05mm). For each size fraction and their composite (sediment), batch experiments were performed to determine uranium adsorption isotherms, and stirred flow-cell experiments were conducted to derive kinetic data of uranium adsorption and subsequent desorption. The results showed that uranium adsorption isotherms and adsorption/desorption kinetics were size-specific, reflecting the effects of size-specific adsorption site concentration and kinetic rate constants. The larger-size fraction had a larger mass percentage in the sediment, but with a smaller adsorption site concentration and generally a slower uranium adsorption/desorption rate. The same equilibrium surface complexation reaction and reaction constant could describe uranium adsorption isotherms for all size fractions and the composite after accounting for the effect of adsorption site concentration. Mass-weighted, linear additivity was observed for both uranium adsorption isotherms and adsorption/desorption kinetics in the composite. Our analysis also showed that uranium adsorption site concentration estimated from the adsorption isotherms was 3 orders of magnitude less than a site concentration estimated from sediment surface area and generic site density. One important implication of this study is that grain size distribution may be used to estimate uranium adsorption site, and adsorption/desorption kinetic rates in heterogeneous sediments from a common location.
Shang, Jianying; Liu, Chongxuan; Wang, Zheming; Zachara, John M.
Inflation by purely kinetic coupled gravity
We study a purely kinetic coupled scalar-tensor gravity. We use FRW metric and obtain the modified Friedmann equations subject to an effective perfect fluid including energy density $\\rho_{\\phi}=\\rho_{g}+\\rho_{_G}$ and pressure $p_{\\phi}=p_{g}+p_{_G}$, where $(\\rho_{g}, p_{g})$ and $(\\rho_{_G}, p_{_G})$ define the perfect fluids corresponding to the coupling of scalar field dynamics with metric and Einstein tensors, respectively. We find that the inflation can occur in this model provided that $p_{_G}=-\\rho_{_G}$. We define Hubble slow-role parameters and find that the Hubble slow-role regime means $\\rho_{_{g}}\\ll\\rho_{_{G}}$. It turns out that the energy is not conserved for the scalar field and its kinetic energy is growing exponentially during inflation. It is proposed that this energy may be supplied by the quantum fluctuations of vacuum. This rapid transfer of energy density from vacuum to the scalar field may solve the cosmological constant problem. When $\\rho_{_{g}}$ becomes sufficiently large, the Hubble parameter starts decreasing and $\\rho_{_{g}}$ becomes comparable with $\\rho_{_{G}}$, hence the slow-role approximation is violated, and the inflation is ended. The large energy density of the scalar field may be transformed, partly into the matter, and partly into the radiation, and the universe experiences a reheating phase. At late times, the kinetic energy of the scalar field decreases as $a^{-6}$ and the remnant energy density of the scalar field may become a source of dark matter. Also, we study the cosmological perturbations during the inflation and obtain the behaviors of perturbations inside and outside the horizon. These results are in agreement with those obtained in common inflationary scenarios.
F. Darabi; A. Parsiya
Kinetics of Anionic Surfactant Anoxic Degradation
The biodegradation kinetics of Geropon TC-42 (trademark) by an acclimated culture was investigated in anoxic batch reactors to determine biokinetic coefficients to be implemented in two biofilm mathematical models. Geropon TC-42 (trademark) is the surfactant commonly used in space habitation. The two biofilm models differ in that one assumes a constant biofilm density and the other allows biofilm density changes based on space occupancy theory. Extant kinetic analysis of a mixed microbial culture using Geropon TC-42 (trademark) as sole carbon source was used to determine cell yield, specific growth rate, and the half-saturation constant for S0/X0 ratios of 4, 12.5, and 34.5. To estimate cell yield, linear regression analysis was performed on data obtained from three sets of simultaneous batch experiments for three S0/X0 ratios. The regressions showed non-zero intercepts, suggesting that cell multiplication is not possible at low substrate concentrations. Non-linear least-squares analysis of the integrated equation was used to estimate the specific growth rate and the half-saturation constant. Net specific growth rate dependence on substrate concentration indicates a self-inhibitory effect of Geropon TC-42 (trademark). The flow rate and the ratio of the concentrations of surfactant to nitrate were the factors that most affected the simulations. Higher flow rates resulted in a shorter hydraulic retention time, shorter startup periods, and faster approach to a steady-state biofilm. At steady-state, higher flow resulted in lower surfactant removal. Higher influent surfactant/nitrate concentration ratios caused a longer startup period, supported more surfactant utilization, and biofilm growth. Both models correlate to the empirical data. A model assuming constant biofilm density is computationally simpler and easier to implement. Therefore, a suitable anoxic packed bed reactor for the removal of the surfactant Geropon TC-42 (trademark) can be designed by using the estimated kinetic values and a model assuming constant biofilm density.
Camacho, Julianna G.
Detecting Ice Nuclei with a Continuous�Flow Diffusion Chamber-Some Exploratory Tests of Instrument Response
A few basic experiments were performed with artificial cloud condensation nuclei and ice-nucleating aerosols in a continuous-flow thermal gradient diffusion chamber to investigate the instrument's response. Brief pulses of ice nuclei were input ...
David C. Rogers
A numerical study of strong kinetic-Alfven turbulence at scales smaller than the ion gyroscale is presented, and a phenomenological model is proposed that argues that magnetic and density fluctuations are concentrated mostly in two-dimensional structures, which leads to their Fourier energy spectra E(k ){proportional_to}k {sup -8/3} , where k is the wavevector component normal to the strong background magnetic field. The results may provide an explanation for recent observations of magnetic and density fluctuations in the solar wind at sub-proton scales.
Boldyrev, Stanislav; Perez, Jean Carlos [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)
Generalized Region Connection Calculus
The Region Connection Calculus (RCC) is one of the most widely referenced system of high-level (qualitative) spatial reasoning. RCC assumes a continuous representation of space. This contrasts sharply with the fact that spatial information obtained from ... Keywords: (Generalized) Boolean connection algebra, (Generalized) Region Connection Calculus, Continuous space, Discrete space, Mereology, Mereotopology, Qualitative spatial reasoning
Sanjiang Li; Mingsheng Ying
NUFinancials General Ledger
NUFinancials General Ledger Reference TroubleshootingGuide Last Updated 11/24/2012 mac © 2010 Northwestern University FMS711 Corrections, Sales, and Transfers Page 1 of 5 Troubleshooting Actuals Journals;NUFinancials General Ledger Reference TroubleshootingGuide Last Updated 11/24/2012 mac © 2010 Northwestern
Shull, Kenneth R.
Measurement of the propagation velocity of single plasma channels in a spark chamber for particle track detection
The velocity of growth of single tracks in a spark chamber is described. It is shown thai in the pressure range 300 < p < 760 torr the tracks propagate with the same velocity to the anode and cathode provided that E/p remains below an experimentally determined value. A rise of this value causes an asymmetry, which makes the chamber no longer suited for the track localization of ionizing particles. (GE)
Timm, U.
APP-005 APP-005 Planning for and Measuring Office of Inspector General Results FY 2002 Annual Performance Report and FY 2003 Annual Performance Plan Office of Inspector General U.S. Department of Energy Inspector General's Message We are pleased to present the Office of Inspector General's (OIG) consolidated Fiscal Year 2002 Annual Performance Report and Fiscal Year 2003 Annual Performance Plan. This document evaluates our actual Fiscal Year (FY) 2002 performance and establishes the performance goals and strategies we will pursue in FY 2003 to fulfill our mission. As mandated by the Inspector General Act, the OIG promotes the effective, efficient, and economical operation of the Department of Energy's programs and operations, including the National Nuclear Security Administration (NNSA).
Spatial redistribution of turbulent and mean kinetic energy
The turbulent spatial redistribution of turbulent and mean kinetic energy and its exchange is investigated in the framework of an K-{epsilon} model in a magnetized plasma column. The kinetic energy is transferred from the turbulence into the zonal flow around the shear layer. The Reynolds stress profile adjusts to the shear layer, which results in a transport of mean kinetic energy from the region around the shear layer into the shear layer.
Manz, P.; Xu, M.; Fedorczak, N.; Thakur, S. C.; Tynan, G. R. [Center for Momentum Transport and Flow Organization,University of California at San Diego, San Diego, California 92093 (United States); Center for Energy Research, University of California at San Diego, San Diego, California 92093 (United States)
Kinetics of zeolite dealumination in steam
Zeolite dealumination is a well known phenomenon that contributes to the deactivation or activation of catalysts in several different applications. The most obvious effect is in acid catalysis where dealumination under reaction conditions removes the Broensted sites, thus deactivating the catalyst. The authors are interested in the use of cation exchanged zeolites as selective reduction catalysts for removal of NO{sub x} from exhaust streams, particularly from automotive exhaust. In this case, copper exchanged ZSM-5 has been shown to be an effective catalyst for the generic reaction of NO{sub x} with hydrocarbons. However, high temperature and steam in combustion exhaust causes dealumination and consequent migration of copper out of the zeolite structure resulting in rapid deactivation of the catalyst. Dealumination of zeolites has been reported by many authors in uncountable papers and cannot be reviewed here. However, to the authors` knowledge there are no reports on the kinetics of dealumination under varying conditions of temperature and steam. By measuring the kinetics of dealumination with different zeolites and exchange cations they expect to develop working models of the dealumination process that will allow control of zeolite deactivation. This manuscript is a description of the basic techniques used and a progress report on the very beginning of this study.
Hughes, C.D.; Labouriau, A.; Crawford, S.N.; Romero, R.; Quirin, J.; Earl, W.L.
PBXN-9 Ignition Kinetics and Deflagration Rates
The ignition kinetics and deflagration rates of PBXN-9 were measured using specially designed instruments at LLNL and compared with previous work on similar HMX based materials. Ignition kinetics were measured based on the One Dimensional Time-to-Explosion combined with ALE3D modeling. Results of these experiments indicate that PBXN-9 behaves much like other HMX based materials (i.e. LX-04, LX-07, LX-10 and PBX-9501) and the dominant factor in these experiments is the type of explosive, not the type of binder/plasticizer. In contrast, the deflagration behavior of PBXN-9 is quite different from similar high weight percent HMX based materials (i.e LX-10, LX-07 and PBX-9501). PBXN-9 burns in a laminar manner over the full pressure range studied (0-310 MPa) unlike LX-10, LX-07, and PBX-9501. The difference in deflagration behavior is attributed to the nature of the binder/plasticizer alone or in conjunction with the volume of binder present in PBXN-9.
Glascoe, E; Maienschein, J; Burnham, A; Koerner, J; Hsu, P; Wemhoff, A
Direct Kinetic Measurements of a Criegee Intermediate
Direct Kinetic Measurements of a Criegee Intermediate Print Direct Kinetic Measurements of a Criegee Intermediate Print In the earth's troposphere, which blankets the planet surface where we live and breathe, dust particles, gas molecules, water vapor, and sunlight provide the ingredients for a multitude of chemical reactions that can generate effects ranging from clouds and smog to acid rain and climate change. In 1949, chemist Rudolf Criegee proposed a novel chemical pathway for one such reaction, known as ozonolysis: the destruction of alkenes (a type of hydrocarbon), via reaction with ozone, a key pollutant in the troposphere. Although there has been much indirect evidence supporting Criegee's mechanism, breakthrough research done at the ALS by chemists from Sandia National Laboratories, the University of Manchester, and Bristol University has for the first time directly measured reaction rates for so-called "Criegee intermediates," elusive molecules formed at intermediate stages of ozonolysis. The surprising results may have important implications for subjects ranging from advanced engine design to air quality and climate modeling.
The Thermodynamics and Kinetics of Dissolution of Coarse Particles ...
A model of the kinetics of dissolution of Nb-rich and Nb2C particles in .... The Influence of Specimen Fabrication Method on the Measured Tensile�...
Chemical Dynamics, Molecular Energetics, and Kinetics at the Synchrotron
novel�measurements�of�chemical�dynamics�for�clusters,�Chemical Dynamics, Molecular Energetics, and Kinetics at theUniversity of California Chemical Sciences Division,
Leone, Stephen R.
Dissolution Kinetics of Steelmaking Slag and Its Promotion for the ...
Presentation Title, Dissolution Kinetics of Steelmaking Slag and Its Promotion for the Growth of Algae. Author(s), Chunfang Zi, Kai Huang, Lianyun Liu, Xiaohui�...
Thermo -Dynamic & -Kinetic Modeling to Quantify the Evolution of ...
The thermo-kinetic model is applied on various chemical compositions of type ... Application of the Phase-Field Model to Four-Phase Reactions in Ternary Alloys.
Kinetic Simulations of Fusion Energy Dynamics at the Extreme...
Kinetic Simulations of Fusion Energy Dynamics at the Extreme Scale PI Name: William Tang PI Email: firstname.lastname@example.com Institution: Princeton Plasma Physics Laboratory Allocation...
Kinetics, Transport, and Structure in Hard and Soft Materials - TMS
Jul 25, 2007 ... REVIEWED BY: Stephen Rankin, associate professor, University of Kentucky. In his book Kinetics, Transport, and Structure in Hard and Soft�...
Oxygen Exchange Kinetics on SOFC Cathode Materials: Importance ...
Presentation Title, Oxygen Exchange Kinetics on SOFC Cathode Materials: Importance of Ionic and Electronic Carriers. Author(s), Rotraut Merkle, Lei Wang,
Kinetic Modeling of Esterification of Ethylene Glycol with Acetic Acid
The reaction kinetics of the esterification of ethylene glycol with acetic acid in the presence of cation exchange resin has been studied and kinetic models based on empirical and Langmuir approach has been developed. The Langmuir based model involving eight kinetic parameters fits experimental data much better compared to empirical model involving four kinetic parameters. The effect of temperature and catalyst loading on the reaction system has been analyzed. Further, the activation energy and frequency factor of the rate constants for Langmuir based model has been estimated.
Yadav, Vishnu P.; Maity, Sunil K. [Department of Chemical Engineering, Indian Institute of Technology, Hyderabad, Ordnance Factory Estate, Yeddumailiram-502205, Andhra Pradesh (India); Mukherjee, Rudra Palash [Department of Chemical Engineering, National Institute of Technology, Durgapur, Mahatma Gandhi Avenue, Durgapur-713209, West Bengal (India); Bantraj, Kandi [Department of Chemical Engineering, National Institute of Technology, Rourkela-769008, Orissa (India)
3.205 Thermodynamics and Kinetics of Materials, Fall 2003
Laws of thermodynamics applied to materials and materials processes. Solution theory. Equilibrium diagrams. Overview of fluid transport processes. Kinetics of processes that occur in materials, including diffusion, phase ...
Allen, Samuel M.
Defect Chemistry and Kinetics of Electrons in Ion Conducting Materials
Presentation Title, Defect Chemistry and Kinetics of Electrons in Ion Conducting Materials � Recent Results and Applications. Author(s), Hans D. Wiemh�fer.
Particle Size Distribution Model for Leaching Kinetics of Alumina
Presentation Title, Particle Size Distribution Model for Leaching Kinetics of Alumina. Author(s), Li Bao, Ting-an Zhang, Weimin Long, Anh V Nguyen, Guozhi Lv,�...
A Kinetic Monte Carlo Model for Material Aging: Simulations of ...
In this paper, we develop a kinetic Monte Carlo framework aiming at ... A Controlled Stress Energy Minimization Method for Coarse-grained Atomistic Simulation.
Thermal Stabilization of Nanocrystalline Grain Size by Kinetic and ...
This talk will review both kinetic and thermodynamic mechanisms and ... Basic Criteria for Formation of Growth Twins in High Stacking Fault Energy Metals.
An Integrated CALPHAD Tool for Modeling Precipitation Kinetics ...
Presentation Title, An Integrated CALPHAD Tool for Modeling Precipitation Kinetics and Accelerating Materials Design. Author(s), Qing Chen, Herng-Jeng Jou,�...
Kinetics of Supercritical Water Reformation of Ethanol to H
Sep 16, 2007 ... Description Kinetics of the supercritical water reformation of ethanol was experimentally studied in a tubular reactor made of Inconel 625 alloy.
Kinetic characterization of enhanced lipase activity on oil bodies
reaction kinetics of oil bodies versus oil emulsions as sub- strates for lipolytic ... of hydrolysis for the oil body system was comparatively very low due to a brief�...
Filling the vacuum chamber of a technological system with homogeneous plasma using a stationary glow discharge
Experimental study of a glow discharge with electrostatic confinement of electrons is carried out in the vacuum chamber volume V {approx} 0.12 m{sup 3} of a technological system 'Bulat-6' in argon pressure range 0.005-5 Pa. The chamber is used as a hollow cathode of the discharge with the inner surface area S {approx} 1.5 m{sup 2}. It is equipped with two feedthroughs, which make it possible to immerse in the discharge plasma interchangeable anodes with surface area S{sub a} ranging from {approx}0.001 to {approx}0.1 m{sup 2}, as well as floating electrodes isolated from both the chamber and the anode. Dependences of the cathode fall U{sub c} = 0.4-3 kV on the pressure p at a constant discharge current in the range I = 0.2-2 A proved that aperture of the electron escape out of the electrostatic trap is equal to the sum S{sub o} = S{sub a} + S{sub f} of the anode surface S{sub a} and the floating electrode surface S{sub f}. The sum S{sub o} defines the lower limit p{sub o} of the pressure range, in which U{sub c} is independent of p. At p fall U{sub c} grows up dramatically, when the pressure decreases, and the pressure p tends to the limit p{sup ex}, which is in fact the discharge extinction pressure. At p {approx} p{sup ex} electrons emitted by the cathode and the first generation of fast electrons produced in the cathode sheath spend almost all their energy up to 3 keV on heating the anode and the floating electrode up to 600-800{sup o}C and higher. In this case the gas in the chamber is being ionized by the next generations of electrons produced in the cathode sheath, their energy being one order of magnitude lower. When S{sub a} fall of potential U{sub a} up to 0.5 kV.
Metel, A. S., E-mail: email@example.com; Grigoriev, S. N.; Melnik, Yu. A.; Panin, V. V. [Moscow State University of Technology 'Stankin' (Russian Federation)
Direct measurement of the impulse in a magnetic thrust chamber system for laser fusion rocket
An experiment is conducted to measure an impulse for demonstrating a magnetic thrust chamber system for laser fusion rocket. The impulse is produced by the interaction between plasma and magnetic field. In the experiment, the system consists of plasma and neodymium permanent magnets. The plasma is created by a single-beam laser aiming at a polystyrene spherical target. The impulse is 1.5 to 2.2 {mu}Ns by means of a pendulum thrust stand, when the laser energy is 0.7 J. Without magnetic field, the measured impulse is found to be zero. These results indicate that the system for generating impulse is working.
Maeno, Akihiro; Yamamoto, Naoji; Nakashima, Hideki [Interdisciplinary Graduate School of Engineering Science, Kyushu University, 6-1 Kasuga-kouen, Kasuga, Fukuoka 816-8580 (Japan); Fujioka, Shinsuke; Johzaki, Tomoyuki [Institute of Laser Engineering, Osaka University, Suita, Osaka 565-087 (Japan); Mori, Yoshitaka [Graduate School for the Creation of New Photonics Industries, Hamamatsu, Shizuoka 431-1202 (Japan); Sunahara, Atsushi [Institute for Laser Technology, Suita, Osaka 565-087 (Japan)
Analysis of Combustion Chamber Deposits by ESI-TOF-MS and MALDI-TOF-MS
Combustion chamber deposits (CCDs) in internal combustion engines have been studied by various techniques to understand the relationship of performance degradation with deposit quantity and structure. XPS, XAS, NMR, and elemental analysis have offered insight into the bulk structure of C, H, N, O and metal components [1]. MS has offered some information about compound structure, but results are limited due to the insolubility and complexity of the materials. Recent advances in MS have opened new possibilities for analysis of CCDs. Here we report initial findings on the carbon structure of these deposits determined by ESI-TOF-MS and MADLI-TOF-MS.
Reynolds, J G; Shields, S J; Roos, J W
Voltage Pulse Profile Characteristics with Space Charge of a Loaded Pulsed Ionization Chamber
An analytical model describing the voltage pulse profile of a pulsed ionization chamber and its relationship to the electron density in a field drift dominated plasma is formulated. The differential equation derived from the equations of motion and conservation of electron density combined with Poisson's equation for the electric space?charge field in the system is solved analytically for the cylindrical?electrode geometry with an external RC circuit. The numerical analysis for the given initial and boundary conditions yields the anode voltage?signal pulse profiles for the period of electron collection as a function of the initial electron density
S.H. Kim; W.H. Ellis
Stochastic cooling of bunched beams from fluctuation and kinetic theory
A theoretical formalism for stochastic phase-space cooling of bunched beams in storage rings is developed on the dual basis of classical fluctuation theory and kinetic theory of many-body systems in phase-space. The physics is that of a collection of three-dimensional oscillators coupled via retarded nonconservative interactions determined by an electronic feedback loop. At the heart of the formulation is the existence of several disparate time-scales characterizing the cooling process. Both theoretical approaches describe the cooling process in the form of a Fokker-Planck transport equation in phase-space valid up to second order in the strength and first order in the auto-correlation of the cooling signal. With neglect of the collective correlations induced by the feedback loop, identical expressions are obtained in both cases for the coherent damping and Schottky noise diffusion coefficients. These are expressed in terms of Fourier coefficients in a harmonic decomposition in angle of the generalized nonconservative cooling force written in canonical action-angle variables of the particles in six-dimensional phase-space. Comparison of analytic results to a numerical simulation study with 90 pseudo-particles in a model cooling system is presented.
Chattopadhyay, S.
Thermodynamics and Kinetics of Carbon Dioxide Binding to Two Stereoisomers
Binding to Stereoisomers of a Cobalt(I) Macrocycle Binding to Stereoisomers of a Cobalt(I) Macrocycle Carol Creutz, Harold A. Schwarz, James F. Wishart, Etsuko Fujita and Norman Sutin J. Am. Chem. Soc. 113, 3361-3371 (1991) Abstract: The thermodynamics and kinetics of binding of CO2, CO, and H+ to N-racemic and N-meso stereoisomers of the cobalt(I) macrocycle CoL+ (L=5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) have been determined in aqueous media with use of the pulse radiolysis technique and transient ultraviolet-visible spectroscopy. N-rac or N-meso-CoL+ was produced by the hydrated electron reduction of N-rac or N-meso-CoL2+, with tert-butyl alcohol generally added to scavenge hydroxyl radicals. Reactions of both N-rac- and N-meso CoL+ are readily followed by the disappearance of intense ([epsilon] 1 x 104 M-1 cm-1) absorption bands
General Search at HERA A General Search for
1 / 18 General Search at HERA G. Brandt A General Search for New Phenomena at HERA Gerhard Brandt Analysis Presented Paper: Phys. Lett. B 674 (2009), 257 [arxiv:0901.0507] #12;2 / 18 General Search at HERA General Search at HERA G. Brandt The H1 General Search General Search for Physics beyond the Standard
Office of Legacy Management (LM)
from the U.S. Department of Energy (DOE). Discussions between DOE and General Atomics led to an agreed cost-sharing and no-fee arrangement for the decontamination and site...
Anomaly General Circulation Models
Anomally models based on a spectral general circulation model (GCM) are formulated and applied to study of low-frequency atmospheric variability in the extratropics, and long-range forecasting research. A steady linear version of the anomaly ...
A. Navarra; K. Miyakoda
General Laser Measurements
General Measurements for Laser Meters. ... 90 to 0 dBm. 0 to 30 dBm. AO 2005, Igor Vayshenker. Laser Dose, 193 nm, SP250-56, David Livigni. ...
2011 IAEA General Conference
2011 IAEA General Conference 2011 IAEA General Conference Remarks as Prepared for Delivery Secretary Steven Chu Monday, September 19, 2011 Thank you, Ambassador Feruta. Congratulations on your election as President of this Conference. I also want to thank Director General Amano for his outstanding leadership. I am honored to represent the United States today, and I want to share a message from President Barack Obama: "On behalf of the United States, please accept my best wishes for a successful International Atomic Energy Agency General Conference. This year's meeting takes place against the backdrop of the severe earthquake and tsunami that struck Japan in March and the devastating accident at the Fukushima Daiichi Nuclear Power Station that followed. Along with
former General former General Atomics Hot Cell Facility was constructed in 1959 and operated until 1991. The site encompassed approximately 7,400 square feet of laboratory and remote operations cells. Licensed operations at the facility included receipt, handling, and shipment of radioactive materials; remote handling, examination, and storage of previously irradiated nuclear fuel materials; pilot-scale tritium extraction operations; and development, fabrication, and inspection of uranium oxide-beryllium oxide fuel materials. General Atomics performed most of the work for the federal government. The General Atomics Hot Cell Facility was located in a 60-acre complex 13 miles northwest of downtown San Diego, 1 mile inland from the Pacific Ocean, and approximately 300 feet above sea level.
former former General Atomics Hot Cell Facility was constructed in 1959 and operated until 1991. The site encompassed approximately 7,400 square feet of laboratory and remote operations cells. Licensed operations at the facility included receipt, handling, and shipment of radioactive materials; remote handling, examination, and storage of previously irradiated nuclear fuel materials; pilot-scale tritium extraction operations; and development, fabrication, and inspection of uranium oxide-beryllium oxide fuel materials. General Atomics performed most of the work for the federal government. The General Atomics Hot Cell Facility was located in a 60-acre complex 13 miles northwest of downtown San Diego, 1 mile inland from the Pacific Ocean, and approximately 300 feet above sea level. The General Atomics site is in the center of Torrey Mesa Science Center, a 304-acre industrial
Dual generalized Bernstein basis
The generalized Bernstein basis in the space @P"n of polynomials of degree at most n, being an extension of the q-Bernstein basis introduced by Philips [Bernstein polynomials based on the q-integers, Ann. Numer. Math. 4 (1997) 511-518], is given by the ... Keywords: Bernstein basis, Big q-Jacobi polynomials, Discrete Bernstein basis, Dual basis, Generalized Bernstein basis, Little q-Jacobi polynomials, Shifted Jacobi polynomials, q -Bernstein basis
Stanis?aw Lewanowicz; Pawe? Wo?ny
, whereas for replicating chemical systems selection is effectively kinetic. Building on an extension. Keywords: biological complexification, chemical evolution, kinetic stability, kinetic state of matter that are kinetically more stable. So though all chemical reactions are governed by a combination of kinetic
Pross, Addy
Development and validation of compressible mixture viscous fluid algorithm applied to predict the evolution of inertial fusion energy chamber gas and the impact of gas on direct-drive target survival
conversion be- tween kinetic (green) and thermal energy (energy lost through ra- diation (red), kinetic (green), andenergy lost through radiation (red), kinetic (green), and
Martin, Robert Scott
Argonne TDC: Intermagnetics General Corporation
Record-setting joint research spurs growth of superconductor market for Argonne partner. Intermagnetics General Corporation Latham, NY. Intermagnetics General ...
Design and optimization of 6li neutron-capture pulse mode ion chamber
The purpose of this research is to design and optimize the performance of a unique, inexpensive 6Li neutron-capture pulse-mode ion chamber (LiPMIC) for neutron detection that overcomes the fill-gas contamination stemming from outgas of detector components. This research also provides a demonstration of performance of LiPMICs. Simulations performed with GARFIELD, a drift-chamber simulation package for ion transport in an electrostatic field, have shown that argon-methane mixtures of fill-gas allow maintenance of electron drift velocity through a surprisingly wide range of fill-gas content. During the design stage of LiPMIC development, the thicknesses of lithium metallization layer, the neutron energy conversion site of the detector, and the thickness of neutron moderator, the high-density polyethylene body, are optimized through analytical and MCNPX calculations. Also, a methodology of obtaining the suitable combination of electric field strength, electron drift velocity, and fill-gas mixtures has been tested and simulated using argon-methane gas mixtures. The LiPMIC is shown to have comparable efficiency to 3He proportional counters at a fraction of cost. Six-month long baseline measurements of overall detector performance shows there is a 3% reduction in total counts for 252Cf sources, which provides a good indicator for the longevity of the detector.
Chung, Kiwhan
A new visible spectroscopy diagnostic for the JET ITER-like wall main chamber
In preparation for ITER, JET has been upgraded with a new ITER-like wall (ILW), whereby the main plasma facing components, previously of carbon, have been replaced by mainly Be in the main chamber and W in the divertor. As part of the many diagnostic enhancements, a new, survey, visible spectroscopy diagnostic has been installed for the characterization of the ILW. An array of eight lines-of-sight (LOS) view radially one of the two JET neutral beam shine through areas (W coated carbon fibre composite tiles) at the inner wall. In addition, one vertical LOS views the solid W tile at the outer divertor. The light emitted from the plasma is coupled to a series of compact overview spectrometers, with overall wavelength range of 380-960 nm and to one high resolution Echelle overview spectrometer covering the wavelength range 365-720 nm. The new survey diagnostic has been absolutely calibrated in situ by means of a radiometric light source placed inside the JET vessel in front of the whole optical path and operated by remote handling. The diagnostic is operated in every JET discharge, routinely monitoring photon fluxes from intrinsic and extrinsic impurities (e.g., Be, C, W, N, and Ne), molecules (e.g., BeD, D{sub 2}, ND) and main chamber and divertor recycling (typically D{alpha}, D{beta}, and D{gamma}). The paper presents a technical description of the diagnostic and first measurements during JET discharges.
Maggi, C. F. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Brezinsek, S. [Forschungszentrum Juelich GmbH, EURATOM Association, D-52425 Juelich (Germany); Stamp, M. F.; Griph, S.; Heesterman, P.; Hogben, C.; Horton, A.; Meigs, A.; Studholme, W.; Zastrow, K.-D. [EURATOM/CCFE, Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Morlock, C. [EFDA-CSU Garching, Boltzmannstrasse 2, 85748 Garching (Germany); Collaboration: JET-EFDA Contributors
CMS reconstruction improvement for the muon tracking by the RPC chambers
The contribution of Resistive Plate Chamber (RPC) to muon reconstruction in CMS has been studied on a sample of muons collected in proton-proton collisions at sqrt(s) = 7 TeV at the LHC in 2011. Muon reconstruction is performed using the all-silicon inner tracker and with up to four stations of gas-ionization muon detectors. Drift Tubes and Cathode Strip Chambers detect muons in the barrel and endcap regions, respectively, and are complemented by the RPC system. Measured distributions of reconstructed hits in the RPCs crossed by muons from Z decays with a transverse momentum pT above 20 GeV/c are well reproduced by the Monte Carlo simulation. From the samples of J/psi and Z events, the efficiencies for muons with and without the inclusion of the RPC hits in the muon track reconstruction are measured and compared with the simulation. Using RPC information in track reconstruction improves up to about 3% of offline reconstruction efficiency for the muons in the region of pT above 7 GeV/c, in good agreement with simulation.
Min Suk Kim on behalf of the CMS Collaboration
Kinetic Energy Systems | Open Energy Information
Systems Systems Jump to: navigation, search Name Kinetic Energy Systems Place Ocala, Florida Zip 34476 Sector Hydro Product Designs and develops tidal generators. Has notably patented the KESC Tidal Generator which is based on free flow hydrodynamics. Coordinates 29.187525°, -82.140394° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":29.187525,"lon":-82.140394,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
A Chemical Kinetic Model of Transcriptional Elongation
A chemical kinetic model of the elongation dynamics of RNA polymerase along a DNA sequence is introduced. The proposed model governs the discrete movement of the RNA polymerase along a DNA template, with no consideration given to elastic effects. The model's novel concept is a ``look-ahead'' feature, in which nucleotides bind reversibly to the DNA prior to being incorporated covalently into the nascent RNA chain. Results are presented for specific DNA sequences that have been used in single-molecule experiments of the random walk of RNA polymerase along DNA. By replicating the data analysis algorithm from the experimental procedure, the model produces velocity histograms, enabling direct comparison with these published results.
Yujiro Richard Yamada; Charles S. Peskin
Kinetics driving high-density chlorine plasmas
A simple fluid model was developed in order to investigate the driving kinetics of neutral and charged species in high-density chlorine plasmas. It was found that the dissociation degree of Cl{sub 2} molecules is directly linked to the power balance of the discharge which controls the electron density. The model was also used to identify those reactions that could be neglected in the particle balance of charged species and those that must be included. Our results further indicate that diffusion losses need to be considered up to a pressure that depends on magnetic-field intensity and reactor aspect ratio. Finally, it is shown that the dominant charged carriers are linked to the dissociation level of Cl{sub 2} molecules.
Stafford, L.; Margot, J.; Vidal, F.; Chaker, M.; Giroux, K.; Poirier, J.-S.; Quintal-Leonard, A.; Saussac, J. [Department de physique, Universite de Montreal, Montreal, Quebec (Canada); INRS-Energie, Materiaux et Telecommunications, Varennes, Quebec (Canada); Department de physique, Universite de Montreal, Montreal, Quebec (Canada)
Spectroscopy, Kinetics, and Dynamics of Combustion Radicals
Spectroscopy, kinetics and dynamics of jet cooled hydrocarbon transients relevant to the DOE combustion mission have been explored, exploiting i) high resolution IR lasers, ii) slit discharge sources for formation of jet cooled radicals, and iii) high sensitivity detection with direct laser absorption methods and near the quantum shot noise limit. What makes this combination powerful is that such transients can be made under high concentrations and pressures characteristic of actual combustion conditions, and yet with the resulting species rapidly cooled (T ?10-15K) in the slit supersonic expansion. Combined with the power of IR laser absorption methods, this provides novel access to spectral detection and study of many critical combustion species.
Nesbitt, David J. [Research/Professor
Towards cleaner combustion engines through groundbreaking detailed chemical kinetic models
Towards cleaner combustion engines through groundbreaking detailed chemical kinetic models of more predictive and more accurate detailed chemical kinetic models for the combustion of fuels that the combustion of liquid fuels will remain the main source of energy for transportation for the next 50 years.1
Pyrolysis kinetics for western and eastern oil shale
Oil yield and kinetic results are reviewed for Western (Colorado Mahogany zone) and Eastern (Sunbury and Ohio (Cleveland member)) oil shales for conditions ranging from those encountered in in-situ processing to those in fluidized-bed retorting. The authors briefly summarize kinetic models for the pyrolysis reactions. Oil yields from Eastern shale are much more sensitive to pyrolysis conditions than Western shale.
Burnham, A.K.; Coburn, T.T.; Richardson, J.H.
Extracting biochemical reaction kinetics from time series data
Abstract. We consider the problem of inferring kinetic mechanisms for biochemical reactions from time series data. Using a priori knowledge about the structure of chemical reaction kinetics we develop global nonlinear models which use elementary reactions as a basis set, and discuss model construction using top-down and bottom-up approaches. 1
Edmund J. Crampin; Patrick E. Mcsharry; Santiago Schnell
Computing realizations of reaction kinetic networks with given properties
engineeringchemical kinetics, chemical thermodynamics, and fluid mechanicsare developed in the second CHEME 3900 Chemical Kinetics and Reactor Design CHEME 4320 Chemical Engineering Laboratory CHEME 4620UndergradUate degree Program as a chemical engineer you'll work with chemical change and chemical
Gorban, Alexander N.
Reconciling competing models: a case study of wine fermentation kinetics
Mathematical models of wine fermentation kinetics promise early diagnosis of stuck or sluggish winemaking processes as well as better matching of industrial yeast strains to specific vineyards. The economic impact of these challenges is significant: ... Keywords: combined and refined model, fermentation problems, mechanistic kinetic models, statistical comparison with experimental data, wine fermentation
Rodrigo Assar; Felipe A. Vargas; David J. Sherman
Solubilty and growth kinetics of silver nitrate in ethanol
The solubility of silver nitrate in ethanol was determined at various temperatures. The growth kinetics of silver nitrate in ethanol were then determined using initial derivaties of temperature and desupersaturation in a mixed-batch crystallizer. For ... Keywords: ethanol, growth kinetics, initial derivatives, silver nitrate, solubility
M. Manteghian; A. Ebrahimi
Nonlinear adaptive control for bioreactors with unknown kinetics
We consider a control problem for a single bioreaction occurring in a continuous and well-mixed bioreactor, assuming that the bioreaction's kinetics is not represented by a validated model. We develop a nonlinear controller and prove the global asymptotic ... Keywords: Continuous bioprocesses, Nonlinear adaptive control, Unknown kinetics, Wastewater treatment
Ludovic Mailleret; Olivier Bernard; Jean-Philippe Steyer
Kinetics of Diuron Adsorption onto Activated Carbon Fiber
A study was conducted on the adsorption kinetics of diuron from aqueous solutions onto activated carbon fiber. The results showed that the formation of hydrogen bonds between diuron and water, and temperature variations may possibly affect the adsorption ... Keywords: activated carbon fiber, diuron adsorption, kinetic models, hydrogen bonds
Jianhua Xu; Yabing Sun; Zhenyu Li; Jingwei Feng
Kinetic electrocaloric effect and giant net cooling of lead-free ferroelectric refrigerants
The electrocaloric effect of BaTiO{sub 3} multilayer thick film structure was investigated by direct measurement using differential scanning calorimeter. The samples show a giant electrocaloric effect of 0.89 J/g under E=176 kV/cm, which also depends on the varying rate of applied field, following a general power-law relation. Based on the large net-cooling (0.37 J/g) resulting from the difference in the varying rates of rising and falling fields, the kinetic electrocaloric effect provides a solution for the design of refrigeration cycle in ferroelectric microrefrigerator.
Bai Yang [Department of Mechanical Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Key Laboratory of Environmental Fracture, University of Science and Technology Beijing, Ministry of Education, Beijing 100083 (China); Zheng Guangping; Shi Sanqiang [Department of Mechanical Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)
Metal Oxidation Kinetics and the Transition from Thin to Thick Films
We report an investigation of growth kinetics and transition from thin to thick films during metal oxidation. In the thin film limit (< 20 nm), Cabrera and Mott�s theory is usually adopted by explicitly considering ionic drift through the oxide in response to electric fields, where the growth kinetics follow an inverse logarithmic law . It is generally accepted that Wagner�s theory, involving self-diffusion, is valid only in the limit of thick film regime (>1?m) and leads to parabolic growth kinetics , where l is the oxide film thickness. Theory presented here unifies the two models and provides a complete description of oxidation including the transition from thin to thick film. The range of validity of Cabrera and Mott�s theory and Wagner�s theory can be well defined in terms of the Debye-H�ckel screening length. The transition from drift-dominated ionic transport for thin film to diffusion-dominated transport for thick film is found to strictly follow the direct logarithmic law that is frequently observed in many experiments.
Xu, Zhijie; Rosso, Kevin M.; Bruemmer, Stephen M.
Chemical kinetic study of the oxidation of toluene and related cyclic compounds
Chemical kinetic models of hydrocarbons found in transportation fuels are needed to simulate combustion in engines and to improve engine performance. The study of the combustion of practical fuels, however, has to deal with their complex compositions, which generally involve hundreds of compounds. To provide a simplified approach for practical fuels, surrogate fuels including few relevant components are used instead of including all components. Among those components, toluene, the simplest of the alkyl benzenes, is one of the most prevalent aromatic compounds in gasoline in the U.S. (up to 30%) and is a promising candidate for formulating gasoline surrogates. Unfortunately, even though the combustion of aromatics been studied for a long time, the oxidation processes relevant to this class of compounds are still matter of discussion. In this work, the combustion of toluene is systematically approached through the analysis of the kinetics of some important intermediates contained in its kinetic submechanism. After discussing the combustion chemistry of cyclopentadiene, benzene, phenol and, finally, of toluene, the model is validated against literature experimental data over a wide range of operating conditions.
Mehl, M; Frassoldati, A; Fietzek, R; Faravelli, T; Pitz, W; Ranzi, E
General User Proposal Scores
General User Proposal Scores General User Proposal Scores General User Proposal Scores Print Tuesday, 01 June 2010 10:34 Scoring Proposals are scored on a scale of 1 to 5, with 1 being the best score and 5 the worst. Reviewers are requested to use the following ranking schema: Must do High Priority Medium Priority Low priority Don't do Beam time is assigned based on each proposal's score in relation to all other proposals for a given beamline. For beamlines where beamtime requests exceed available beamtime, a cutoff score is assigned after which no beam time is allocated. proposal scores Beam Time Cutoff Scores for the Current Cycle The table below lists the percent of beam time shifts allocated/requested for each beamline, and the cutoff scores, below which no beam time was assigned.
_______ _______ Change Notice 1 June 2009 DOE HANDBOOK GENERAL EMPLOYEE RADIOLOGICAL TRAINING U.S. Department of Energy AREA TRNG Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Not Measurement Sensitive This document is available on the Department of Energy Technical Standards Program Web Site at http://www.hss.energy.gov/nuclearsafety/techstds/ Change 1 DOE-HDBK-1131-2007 Original Change Part 2 page 5 The average annual radiation dose to a member of the general population is about 360 millirem/year. The average annual radiation dose to a member of the general population is about 620 millirem/year. Part 2 page 5 Natural background radiation is by far the
NEWTON's General Science References
General Science References General Science References Do you have a great general science reference link? Please click our Ideas page. Featured Reference Links: First.gov Science and Technology First.gov Science and Technology This site, sponsered by the US Government provides reference links to topics on science, telecommunications, computers, research agencies, and news. NASA Science NASA Science NASA Science, is a website sponsered by NASA, that supplies resources for understanding our world and the world above. Topics include earth science, heliophysics, the planets, astrophysics and much more. There is also an educator page! Nobel Laueate Listings and Stories Nobel Laueate Listings and Stories See the official site for the Nobel Prize, and read biographies about all of the Nobel Laureates, and there life changing discoveries and accomplishments.
Not Measurement Not Measurement Sensitive DOE-HDBK-1131-2007 December 2007_______ Change Notice 1 Reaffirmed 2013 DOE HANDBOOK GENERAL EMPLOYEE RADIOLOGICAL TRAINING U.S. Department of Energy AREA TRNG Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. This document is available on the Department of Energy Technical Standards Program Web Site at http://www.hss.energy.gov/nuclearsafety/techstds/ Change 1 DOE-HDBK-1131-2007 Original Change Part 2 page 5 The average annual radiation dose to a member of the general population is about 360 millirem/year. The average annual radiation dose to a member of the general population is about 620 millirem/year. Part 2 page 5 Natural background radiation is by far the
Extraction of depth-dependent perturbation factors for parallel-plate chambers in electron beams using a plastic scintillation detector
Purpose: This work presents the experimental extraction of the overall perturbation factor P{sub Q} in megavoltage electron beams for NACP-02 and Roos parallel-plate ionization chambers using a plastic scintillation detector (PSD). Methods: The authors used a single scanning PSD mounted on a high-precision scanning tank to measure depth-dose curves in 6, 12, and 18 MeV clinical electron beams. The authors also measured depth-dose curves using the NACP-02 and PTW Roos chambers. Results: The authors found that the perturbation factors for the NACP-02 and Roos chambers increased substantially with depth, especially for low-energy electron beams. The experimental results were in good agreement with the results of Monte Carlo simulations reported by other investigators. The authors also found that using an effective point of measurement (EPOM) placed inside the air cavity reduced the variation of perturbation factors with depth and that the optimal EPOM appears to be energy dependent. Conclusions: A PSD can be used to experimentally extract perturbation factors for ionization chambers. The dosimetry protocol recommendations indicating that the point of measurement be placed on the inside face of the front window appear to be incorrect for parallel-plate chambers and result in errors in the R{sub 50} of approximately 0.4 mm at 6 MeV, 1.0 mm at 12 MeV, and 1.2 mm at 18 MeV.
Lacroix, Frederic; Guillot, Mathieu; McEwen, Malcolm; Cojocaru, Claudiu; Gingras, Luc; Beddar, A. Sam; Beaulieu, Luc [Departement de Radio-Oncologie, Centre hospitalier de l'Universite de Montreal (CHUM), 1560 Sherbrooke Est, Montreal, Quebec H2L 4M1 (Canada) and Departement de Physique, Universite de Montreal, Pavillon Roger-Gaudry (D-428), 2900 Boul. Edouard-Montpetit, Montreal, Quebec H3T 1J4 (Canada); Departement de Physique, de Genie Physique et d'Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada) and Departement de Radio-Oncologie, Ho circumflex tel-Dieu de Quebec, Centre hospitalier Universitaire de Quebec (CHUQ), Quebec, Quebec G1R 2J6 (Canada); Ionizing Radiation Standards, Institute for National Measurement Standards, National Research Council (NRC), Ottawa, Ontario K1A 0R6 (Canada); Departement de Physique, de Genie Physique et d'Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada) and Departement de Radio-Oncologie, Ho circumflex tel-Dieu de Quebec, Centre hospitalier Universitaire de Quebec (CHUQ), Quebec, Quebec G1R 2J6 (Canada); Department of Radiation Physics, Unit 94, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States); Departement de Physique, de Genie Physique et d'Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada) and Departement de Radio-Oncologie, Hotel-Dieu de Quebec, Centre hospitalier Universitaire de Quebec (CHUQ), Quebec, Quebec G1R 2J6 (Canada)
A Novel Approach to Experimental Studies of Mineral Dissolution Kinetics
Currently, DOE is conducting pilot CO{sub 2} injection tests to evaluate the concept of geological sequestration. The injected CO{sub 2} is expected to react with the host rocks and these reactions can potentially alter the porosity, permeability, and mechanical properties of the host or cap rocks. Reactions can also result in precipitation of carbonate-containing minerals that favorably and permanently trap CO{sub 2} underground. Many numerical models have been used to predict these reactions for the carbon sequestration program. However, a firm experimental basis for predicting silicate reaction kinetics in CO{sub 2} injected geological formations is urgently needed to assure the reliability of the geochemical models used for the assessments of carbon sequestration strategies. The funded experimental and theoretical study attempts to resolve this outstanding scientific issue by novel experimental design and theoretical interpretation of silicate dissolution rates at conditions pertinent to geological carbon sequestration. In this four year research grant (three years plus a one year no cost extension), seven (7) laboratory experiments of CO{sub 2}-rock-water interactions were carried out. An experimental design allowed the collection of water samples during experiments in situ and thus prevented back reactions. Analysis of the in situ samples delineated the temporal evolution of aqueous chemistry because of CO{sub 2}-rock-water interactions. The solid products of the experiments were retrieved at the end of the experimental run, and analyzed with a suite of advanced analytical and electron microscopic techniques (i.e., atomic resolution transmission electron microscopy (TEM), scanning electron microscopy (SEM), electron microprobe, X-ray diffraction, X-ray photoelectron spectroscopy (XPS)). As a result, the research project probably has produced one of the best data sets for CO{sub 2}-rock-water interactions in terms of both aqueous solution chemistry and solid characterization. Three experiments were performed using the Navajo sandstone. Navajo sandstone is geologically equivalent to the Nugget sandstone, which is a target formation for a regional partnership injection project. Our experiments provided the experimental data on the potential CO{sub 2}-rock-water interactions that are likely to occur in the aquifer. Geochemical modeling was performed to interpret the experimental results. Our single mineral (feldspar) experiments addressed a basic research need. i.e., the coupled nature of dissolution and precipitation reactions, which has universal implication to the reaction kinetics as it applied to CO{sub 2} sequestration. Our whole rock experiments (Navajo sandstone) addressed the applied research component, e.g., reacting Navajo sandstone with brine and CO{sub 2} has direct relevance on the activities of a number of regional partnerships. The following are the major findings from this project: (1) The project generated a large amount of experimental data that is central to evaluating CO{sub 2}-water-rock interactions and providing ground truth to predictive models, which have been used and will inevitably be increasingly more used in carbon sequestration. (2) Results from the feldspar experiments demonstrated stronger coupling between dissolution and precipitation reactions. We show that the partial equilibrium assumption did not hold in the feldspar hydrolysis experiments (Zhu and Lu, submitted, Appendix A-2). The precipitation of clay minerals influenced dissolution of primary silicate in a much stronger way as previously envisioned. Therefore, our experimental data indicated a much more complex chemical kinetics as it has been applied to carbon sequestration program in terms of preliminary predictive models of CO{sub 2}-rock-water interactions. Adopting this complexity (strong coupling) may influence estimates of mineral trapping and porosity/permeability for geological carbon sequestration. In general, our knowledge of the coupling of different reactions is poor, and we must consider the uncertainties resultin
Chen Zhu
A new approach to the application of the classic methods of physicochemical kinetics in the analysis of the efficiency of plasma technology of coal gasification
This work is devoted to the problem of improving the efficiency of new plasma technologies of coal combustion that have minimum negative environmental impact. In particular, the authors consider a general method of formulating and solving the inverse kinetic problem to elucidate advantages of plasma gasification.
Karpenko, E.I.; Devyatov, B.N. [Kutateladze Inst. of Thermal Physics, Novosibirsk (Russian Federation)
Generalized Lorentz Transformations
Generalized Lorentz transformations with modified velocity parameter are considered. Lorentz transformations depending on the mass of the observer are suggested.The modified formula for the addition of velocities remarkably preserves the constancy of the velocity of light for all observers. The Doppler red shift is affected and can provide a test of such generalisations.
Virendra Gupta
As part of the U.S. Department of Energy (DoE) initiative to improve the efficiency of coal-fired power plants and reduce the pollution generated by these facilities, DOE has funded the High-Pressure Coal Combustion Kinetics (HPCCK) Projects. A series of laboratory experiments were conducted on selected pulverized coals at elevated pressures with the specific goals to provide new data for pressurized coal combustion that will help extend to high pressure and validate models for burnout, pollutant formation, and generate samples of solid combustion products for analyses to fill crucial gaps in knowledge of char morphology and fly ash formation. Two series of high-pressure coal combustion experiments were performed using SRI's pressurized radiant coal flow reactor. The first series of tests characterized the near burner flame zone (NBFZ). Three coals were tested, two high volatile bituminous (Pittsburgh No.8 and Illinois No.6), and one sub-bituminous (Powder River Basin), at pressures of 1, 2, and 3 MPa (10, 20, and 30 atm). The second series of experiments, which covered high-pressure burnout (HPBO) conditions, utilized a range of substantially longer combustion residence times to produce char burnout levels from 50% to 100%. The same three coals were tested at 1, 2, and 3 MPa, as well as at 0.2 MPa. Tests were also conducted on Pittsburgh No.8 coal in CO2 entrainment gas at 0.2, 1, and 2 MPa to begin establishing a database of experiments relevant to carbon sequestration techniques. The HPBO test series included use of an impactor-type particle sampler to measure the particle size distribution of fly ash produced under complete burnout conditions. The collected data have been interpreted with the help of CFD and detailed kinetics simulation to extend and validate devolatilization, char combustion and pollutant model at elevated pressure. A global NOX production sub-model has been proposed. The submodel reproduces the performance of the detailed chemical reaction mechanism for the NBFZ tests.
Stefano Orsino
Chamber Surface Roughness and Electron Cloud for the Advanced Photon Source Superconducting Undulator
The electron cloud is a possible heat source in the superconducting undulator (SCU) designed for the Advanced Photon Source (APS), a 7-GeV electron synchrotron radiation source at Argonne National Laboratory. In electron cloud generation extensive research has been done, and is continuing, to understand the secondary electron component. However, little work has been done to understand the parameters of photoemission in the accelerator environment. To better understand the primary electron generation in the APS; a beamline at the Australian Light Source synchrotron was used to characterize two samples of the Al APS vacuum chamber. The total photoelectron yield and the photoemission spectra were measured. Four parameters were varied: surface roughness, sample temperature, incident photon energy, and incident photon angle, with their results presented here.
Boon, Laura
Length and Straightness of the Tubes for the BOS Prototype Chamber
We have measured length and straightness of 50 tubes of 3.8~m length, after cleaning, wiring and testing from a batch that was used in the construction of the BOS prototype chamber. The specifi ed length (aluminum tube only, without endplug) was 3800~mm with a tolerance of $\\pm$1~mm. We found a mean value of (3805$\\pm$2)~mm with a standard deviation of (0.3$\\pm$0.1)~mm. The measureme nts of the straightness of the 50 BOS MDT tubes gave a mean of the maximum deviation of 150~$\\mu$m for 10 measured points along the tubes at 0$^{\\circ}$, 90$^{\\circ}$, 180$^{\\circ}$ and 270$^{\\circ }$ around the tube diameter and a mean value of all deviations of 20~$\\mu$m with a measuring accuracy of 10~$\\mu$m.
Lagouri, T
Combustion chamber deposits (CCD) in internal combustion engines have been studied by various techniques to understand the relationship of performance degradation with deposit quantity and structure. XPS, XAS, NMR, and elemental analysis have offered insight into the bulk structure of C, H, N, O and metal components. MS has offered some information about compound structure, but results are limited due to the insolubility and complexity of the materials. Recently, we have reported on the metal structure by XPS and XAS of several deposits from a GM 3800 engine generated using a standard fuel and one that contains low levels of the gasoline anti-knock additive, MMT. Here we report the initial findings on the carbon structure of these deposits determined by ESI-TOF-MS and MADLI-TOF-MS.
Measurement of electrical properties of electrode materials for the bakelite Resistive Plate Chambers
Single gap (gas gap 2 mm) bakelite Resistive Plate Chamber (RPC) modules of various sizes from 10 cm \\times 10 cm to 1 m \\times 1 m have been fabricated, characterized and optimized for efficiency and time resolution. Thin layers of different grades of silicone compound are applied to the inner electrode surfaces to make them smooth and also to reduce the surface resistivity. In the silicone coated RPCs an efficiency > 90% and time resolution \\sim 2 ns (FWHM) have been obtained for both the streamer and the avalanche mode of operation. Before fabrication of detectors the electrical properties such as bulk resistivity and surface resistivity of the electrode materials are measured carefully. Effectiveness of different silicone coating in modifying the surface resistivity was evaluated by an instrument developed for monitoring the I-V curve of a high resistive surface. The results indicate definite correlation of the detector efficiency for the atmospheric muons and the RPC noise rates with the surface resistiv...
Meghna, K K; Biswas, S; Bhattacharya, S; Bose, S; Chattopadhyay, S; Das, G; Marick, C; Saha, S; Viyogi, Y P
Formation of metal nanoparticles by short-distance sputter deposition in a reactive ion etching chamber
A new method is reported to form metal nanoparticles by sputter deposition inside a reactive ion etching chamber with a very short target-substrate distance. The distribution and morphology of nanoparticles are found to be affected by the distance, the ion concentration, and the sputtering time. Densely distributed nanoparticles of various compositions were fabricated on the substrates that were kept at a distance of 130 mum or smaller from the target. When the distance was increased to 510 mum, island structures were formed, indicating the tendency to form continuous thin film with longer distance. The observed trend for nanoparticle formation is opposite to the previously reported mechanism for the formation of nanoparticles by sputtering. A new mechanism based on the seeding effect of the substrate is proposed to interpret the experimental results.
Nie Min; Meng, Dennis Desheng [Department of Mechanical Engineering and Engineering Mechanics, Michigan Technological University, Houghton, Michigan 49931 (United States); Sun Kai [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)
U.S. Chamber of Commerce's 4th Annual North America Forum | Department of
Commerce's 4th Annual North America Forum Commerce's 4th Annual North America Forum U.S. Chamber of Commerce's 4th Annual North America Forum June 16, 2008 - 1:30pm Addthis Remarks As Prepared for Delivery for Secretary Bodman Thank you very much, Ron, for that kind introduction and for the critically important work that you and your colleagues do at Lawrence Livermore. I also want to thank my good friend Secretary George Shultz - along with his esteemed co-chairs for this event, Peter Lougheed and Pedro Aspe, for inviting me to be with you. It's a pleasure to be here. The way I see it, this event could not come at a better time. With its focus on enhancing cooperation among the United States, Canada and Mexico - and on bringing together representatives of our governments and the private sector - you are helping to develop and achieve real and lasting solutions
Usiing NovoCOS cleaning equipment in repairing the furnace-chamber lining in coke batteries 4 & 5 at OAO Koks
Experience with a new surface-preparation technology for the ceramic resurfacing of the refractory furnace-chamber lining in coke batteries is described.
S.G. Protasov; R. Linden; A. Gross [OAO Koks, Kemerovo (Russian Federation)
Kinetics of the reactions of hydrogen fluoride with calcium oxide
This paper studies the kinetics of interaction of gaseous hydrogen fluoride with calcium oxide at temperatures 300-700 degrees. The experiments were conducted in a laboratory adsorption apparatus modified and adapted for work with corrosive hydrogen fluoride. Calcium oxide samples in granulated form and deposited on gamma-alumina were used in the experiments. Kinetic curves representing variations of the degree of conversion of the solid samples with time are shown. The influence of retardation dure to diffusion was observed in the experiments. The influence of diffusion control on the reaction rate was also observed in a study of the reaction kinetics on supported layers of calcium oxide.
Kossaya, A.M.; Belyakov, B.P.; Kuchma, Z.V.; Sandrozd, M.K.; Vasil'eva, V.G.
Evidence of critical balance in kinetic Alfven wave turbulence simulations
A numerical simulation of kinetic plasma turbulence is performed to assess the applicability of critical balance to kinetic, dissipation scale turbulence. The analysis is performed in the frequency domain to obviate complications inherent in performing a local analysis of turbulence. A theoretical model of dissipation scale critical balance is constructed and compared to simulation results, and excellent agreement is found. This result constitutes the first evidence of critical balance in a kinetic turbulence simulation and provides evidence of an anisotropic turbulence cascade extending into the dissipation range. We also perform an Eulerian frequency analysis of the simulation data and compare it to the results of a previous study of magnetohydrodynamic turbulence simulations.
TenBarge, J. M.; Howes, G. G. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)
Warped General Gauge Mediation
We develop the formalism of "General gauge mediation" for five dimensional theories in a slice of AdS space. A set of current correlators encodes the effect of a supersymmetry breaking hidden sector localised on the IR brane. These current correlators provide a tree-level gaugino mass and loop-level sfermion masses on the UV brane. We also use this formalism to calculate the Casimir energy and masses for bulk hyperscalars. To illustrate this general construction we consider a perturbative hidden sector of generalised messengers coupled to a spurion. For models with large warping, we find that when the AdS warp factor $k$ is less than the characteristc mass scale $M$ of the hidden sector, the whole Kaluza-Klein tower of vector superfields propagate supersymmetry breaking effects to the UV brane. When $M$ is less than $k$, the zero modes dominate.
Moritz McGarrie; Daniel C. Thompson
Tests of General Relativity
The last years have seen continuing activities in the exploration of our understanding of gravity, motivated by results from precision cosmology and new precision astrophysical experiments. At the centre of attention lies the question as to whether general relativity is the correct theory of gravity. In answering this question, we work not only towards correctly interpreting the phenomenon of 'dark energy' but also towards the goal of achieving a quantum theory of gravity. In these efforts, the observations of pulsars, especially those in binary systems, play an important role. Pulsars do not only provide the only evidence for the existence of gravitational waves so far, but they also provide precision tests of general relativity and alternative theories of gravity. This talk summarizes the current state-of-art in these experiments and looks into the future.
Kramer, Michael [MPI fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Jodrell Bank Centre for Astrophysics, University of Manchester, Manchester M13 9PL (United Kingdom)
Generalized Inverse Seesaws
The seesaw mechanism can be generalized to a Type-III variant and a quintuplet variant. We present two models that provide analogous generalizations of the inverse seesaw mechanism. The first model employs a fermion triplet F ~ (1,3,0) and requires no additional multiplets or parameters relative to the standard inverse seesaw. We argue that, from a bottom-up perspective, there appears to be no particular reason to preference the usual scenario over this variant. The second model employs a fermion quintuplet F ~ (1,5,0) and requires an additional scalar S ~ (1,4,1). We also show that minimal inverse seesaws with even larger fermionic representations are not expected to realize naturally small neutrino masses.
Law, Sandy S C
Sandy S. C. Law; Kristian L. McDonald
Office of Inspector General
Inspector General Inspector General Office of Audits and Inspections Work Plan for FY 2013 Audits Central Audits Division Ecotality Funding Overlap Follow-up on Smart Grid Investment Grant DOE's Loan Program Office's Portfolio Management Office of Fossil Energy's Regional Carbon Sequestration Partnerships Advanced Manufacturing Office's Combined Heat and Power Systems DOE's Management of Contaminated Non-EM Facilities Unneeded Real Estate Review of For-Profit Grantees for selected DOE programs Commercialization Efforts at National Laboratories Research Misconduct at Office of Science Public Dissemination of Research Results BPA's Management of Borrowing Authority Construction Controls Over PMA's Use of Hedging Instruments
EMSL: News: General Stories
General News General News Battery development may extend range of electric cars Battery development may extend range of electric cars New anode quadruples life of lithium-sulfur battery, could also help store renewable energy more cheaply Released: January 09, 2014 Scientists used EMSL capabilities and expertise to help develop and test a new anode design for lithium-sulfur batteries. The "hybrid" anode significantly extends the life of lithium-sulfur batteries, bringing them closer to commercial use. Read the PNNL news release. Batteries as they are meant to be seen Batteries as they are meant to be seen The search for long-lasting, inexpensive rechargeable batteries Released: December 27, 2013 Researchers working at EMSL study how a battery works under wet conditions
Determination of cohesive and normal stresses and simulation of fluidization using kinetic theory
The general objective of this study is focused on the solid stresses involved in gas-solid flow. These stresses are generally included in the momentum conservation equations, essentially for stability and to prevent particles from collapsing to unreasonably low values of gas volume fraction. The first half of this work undertakes the measurement of the stresses in various powders by direct means, while the second part uses a newly developed kinetic theory constitutive equation for stress to predict the flow and also the solids viscosity in a CFB. The cohesive or tensile stress found to exist in some classes of powders is measured using a Cohetester, based on which a cohesive force model is derived, which is sensitive to the characteristic properties of the powder material. The normal stress is measured using a Consolidometer, and the powder solids modulus is obtained as a function of the volume fraction. The solids modulus is seen to vary with particle size and particle type, with the smaller size particles being more compressible. The simulation of flow in the CFB using Gidaspow's (1991) extension of Ding's (1990) kinetic theory model to dilute phase flow, predicts realistic values of solids viscosity that are comparable to viscosities obtained experimentally by Miller (1991). However, to obtain a match between the two the value of the restitution coefficient has to be close to unity. The flow behavior showed periodic oscillations of flow (turbulence) as seen in a real system. 26 refs., 51 figs., 1 tab.
Bezbaruah, R.
Kinetics of spin relaxation in quantum wires and channels: Boundary spin echo and formation of a persistent spin helix
In this paper we use a spin kinetic equation to study spin-polarization dynamics in one-dimensional (1D) wires and 2D channels. The spin kinetic equation is valid in both diffusive and ballistic spin transport regimes and therefore is more general than the usual spin drift-diffusion equations. In particular, we demonstrate that in infinite 1D wires with Rashba spin-orbit interaction the exponential spin-relaxation decay can be modulated by an oscillating function. In the case of spin relaxation in finite length 1D wires, it is shown that an initially homogeneous spin polarization spontaneously transforms into a persistent spin helix. We find that a propagating spin-polarization profile reflects from a system boundary and returns back to its initial position similarly to the reflectance of sound waves from an obstacle. The Green's function of the spin kinetic equation is derived for both finite and infinite 1D systems. Moreover, we demonstrate explicitly that the spin relaxation in specifically oriented 2D channels with Rashba and Dresselhaus spin-orbit interactions of equal strength occurs similarly to that in 1D wires of finite length. Finally, a simple transformation mapping 1D spin kinetic equation into the Klein-Gordon equation with an imaginary mass is found thus establishing an interesting connection between semiconductor spintronics and relativistic quantum mechanics.
Slipko, Valeriy A. [Department of Physics and Astronomy and USC Nanocenter, University of South Carolina, Columbia, South Carolina 29208 (United States); Department of Physics and Technology, V. N. Karazin Kharkov National University, Kharkov 61077 (Ukraine); Pershin, Yuriy V. [Department of Physics and Astronomy and USC Nanocenter, University of South Carolina, Columbia, South Carolina 29208 (United States)
ROLES OF THE KINETIC AND DYNAMIC MECHANISMS IN THE L{sub p} -E{sub p} RELATION
The L{sub p} -E{sub p} relation is a well-known relation in gamma-ray bursts (GRBs). Its implication remains unclear. We propose to investigate the underlying mechanisms of this relation by considering the corresponding kinetic and dynamic mechanisms separately. In this way, one can tell how much the kinetic or dynamic mechanism contributes to the index of the relationship. Our analysis gives rise to several conclusions. (1) The index of the kinetic effect in the L{sub p} -E{sub p} relation can simply be derived from the theory of special relativity, which is generally larger than 2, depending on the situation concerned. (2) The index of the dynamic effect in the relation can be deduced from observation once a model of jets is adopted. According to current GRB data, we find that the dynamic effect alone tends to give rise to an anti-correlation between L{sub p} and E{sub p} ; in terms of statistics, the dynamic effect is obviously smaller than the kinetic effect; in the situation of jets with moving discrete radio clouds that move directly toward the observer, the index of the dynamic effect is currently constrained within (- 1.6, -1), while in other situations of jets, the constraints are different; both internal and external shocks can account for the current data.
Qin, Yi-Ping; Chen, Zhi-Fu, E-mail: email@example.com [Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China)] [Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China)
General Employee Radiological Training (GERT)
General Employee Radiological Training (GERT) Radiological Training for NSLS Access has been replaced with BNL General Employee Radiological Training (GERT). Please read the...
An Improved Equilibrium-Kinetics Speciation Algorithm For Redox Reactions
Improved Equilibrium-Kinetics Speciation Algorithm For Redox Reactions Improved Equilibrium-Kinetics Speciation Algorithm For Redox Reactions In Variably Saturated Subsurface Flow Systems Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: An Improved Equilibrium-Kinetics Speciation Algorithm For Redox Reactions In Variably Saturated Subsurface Flow Systems Details Activities (0) Areas (0) Regions (0) Abstract: Reactive chemical transport occurs in a variety of geochemical environments, and over a broad range of space and time scales. Efficiency of the chemical speciation and water-rock-gas interaction calculations is important for modeling field-scale multidimensional reactive transport problems. An improved efficient model, REACT, for simulating water-rock-gas interaction under equilibrium and kinetic conditions, has been developed.
Automated generation of kinetic chemical mechanisms using rewriting
Several software systems have been developed recently for the automated generation of combustion reactions kinetic mechanisms using different representations of species and reactions and different generation algorithms. In parallel, several software ...
Olivier Bournez; Guy-Marie C�me; Val�rie Conraud; H�l�ne Kirchner; Liliana Ib?nescu
Evaluation of the Turbulent Kinetic Energy Dissipation Rate Inside ...
Abstract Inferring the vertical variation of the mean turbulent kinetic energy ..... the times at which a threshold-crossings occurs are defined by the indicator function .... of noise infection and noise intensity, introducing a threshold Tc significantly�...
The Mesoscale Kinetic Energy Spectrum of a Baroclinic Life Cycle
The atmospheric mesoscale kinetic energy spectrum is investigated through numerical simulations of an idealized baroclinic wave life cycle, from linear instability to mature nonlinear evolution and with high horizontal and vertical resolution (?x ...
Michael L. Waite; Chris Snyder
ESS 2012 Peer Review - Amber Kinetics Flywheel Energy Storage...
7700 RPM - Spin testing accelerates rotor to: 530 ms and 11,000 RPM - Rotor stores 10 kWh of kinetic energy @ 11,000 RPM (2x more than design speed) - All testing conducted in...
Fundamental kinetic modeling of the catalytic reforming process
In this work, a fundamental kinetic model for the catalytic reforming process has been developed. The complex network of elementary steps and molecular reactions occurring in catalytic reforming has been generated through a computer algorithm characterizing ...
Rogelio Sotelo-Boyas / Gilbert F. Froment; Rayford G. Anthony
Estimates of Kinetic Energy Dissipation under Breaking Waves
The dissipation of kinetic energy at the surface of natural water bodies has important consequences for many Physical and biochemical processes including wave dynamics, gas transfer, mixing of nutrients and pollutants, and photosynthetic ...
E.A. Terray; M.A. Donelan; Y.C. Agrawal; W.M. Drennan; K.K. Kahma; A.J. Williams; P.A. Hwang; S.A. Kitaigorodskii
The Track Integrated Kinetic Energy of Atlantic Tropical Cyclones
In this paper the concept of track integrated kinetic energy (TIKE) is introduced as a measure of seasonal Atlantic tropical cyclone activity and applied to seasonal variability in the Atlantic. It is similar in concept to the more commonly used ...
V. Misra; S. DiNapoli; M. Powell
Kinetic model reduction using integer and semi-infinite programming
In this work an optimization-based approach to kinetic model reduction was studied with a view to generating reduced-model libaries for reacting-flow simulations. A linear integer formulation of the reaction elimination ...
Bhattacharjee, Binita, 1976-
Turbulence Kinetic Energy Budget Profiles Derived from Doppler Sodar Measurements
Doppler sodar wind measurements made in light wind conditions in September 1979 near a power plant in Turbigo, Italy, are used to derive terms in the turbulence kinetic energy (TKE) budget. Measurements on five days are grouped into two classes: ...
Gary K. Greenhut; Giangiuseppe Mastrantonio
Reversibility and Non-reversibility in Stochastic Chemical Kinetics
Mathematical problems with mean field and local type interaction related to stochastic chemical kinetics,are considered. Our main concern various definitions of reversibility, their corollaries (Boltzmann type equations, fluctuations, Onsager relations, etc.) and emergence of irreversibility.
Malyshev, V A
Determining Turbulent Kinetic Energy Dissipation from Batchelor Curve Fitting
An algorithm is presented for obtaining the rate of turbulent kinetic energy dissipation by fitting the theoretical Batchelor spectrum to the temperature gradient spectrum at high wavenumbers. The algorithm is relatively robust in selecting the ...
David A. Luketina; J�rg Imberger
Solar wind plasma : kinetic properties and micro-instabilities
The kinetic properties of ions in the solar wind plasma are studied. Observations of solar wind +H and +2He by the Faraday Cup instrument component of the Solar Wind Experiment on the Wind spacecraft show that these ions ...
Kasper, Justin Christophe, 1977-
Kinetic Energy Transfer between Internal Gravity Waves and Turbulence
We describe a reliable method for distinguishing the mean, wave and turbulence fields when internal waves with changing amplitude perturb the turbulent boundary layer. By integrating the component wave and turbulence kinetic energy budgets ...
J. J. Finnigan
Ducted kinetic Alfven waves in plasma with steep density gradients
Given their high plasma density (n {approx} 10{sup 13} cm{sup -3}), it is theoretically possible to excite Alfven waves in a conventional, moderate length (L {approx} 2 m) helicon plasma source. However, helicon plasmas are decidedly inhomogeneous, having a steep radial density gradient, and typically have a significant background neutral pressure. The inhomogeneity introduces regions of kinetic and inertial Alfven wave propagation. Ion-neutral and electron-neutral collisions alter the Alfven wave dispersion characteristics. Here, we present the measurements of propagating kinetic Alfven waves in helium helicon plasma. The measured wave dispersion is well fit with a kinetic model that includes the effects of ion-neutral damping and that assumes the high density plasma core defines the radial extent of the wave propagation region. The measured wave amplitude versus plasma radius is consistent with the pile up of wave magnetic energy at the boundary between the kinetic and inertial regime regions.
Houshmandyar, Saeid [Solar Observatory Department, Prairie View A and M University, Prairie View, Texas 77446 (United States); Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Scime, Earl E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)
Momentum and Kinetic Energy Budgets of Simulated Supercell Thunderstorms
The results of numerical simulations of severe thunderstorms with rotating updrafts and supercell characteristics are analyzed to determine their sources, sinks, and transports of momentum and kinetic energy. Two simulations are used, one ...
Douglas K. Lilly; Brian F. Jewett
Kinetic Monte Carlo simulations of nanocrystalline film deposition
A full diffusion kinetic Monte Carlo algorithm is used to model nanocrystalline film deposition, and study the mechanisms of grain nucleation and microstructure formation in such films. The major finding of this work is ...
Ruan, Shiyun
Kinetic modeling and automated optimization in microreactor systems
The optimization, kinetic investigation, or scale-up of a reaction often requires significant time and materials. Silicon microreactor systems have been shown advantageous for studying chemical reactions due to their small ...
Moore, Jason Stuart
Kinetics, Mechanics and Microstructure Changes in Storage Media
Program Review Crystal Gateway Marriott, Crystal City, VA May 18, 2006 Kinetics, Mechanics and Microstructure Changes in Storage Media Anter El-Azab Tel: 850-410-6655, E-mail...
LLNL researchers develop first kinetic model of plasma focus...
13013device 01302013 LLNL researchers develop first kinetic model of plasma focus device Anne M Stark, LLNL, (925) 422-9799, email@example.com Printer-friendly Deuterium ion...
Topobo : a 3-D constructive assembly system with kinetic memory
We introduce Topobo, a 3-D constructive assembly system em- bedded with kinetic memory, the ability to record and playback physical motion. Unique among modeling systems is Topobo's coincident physical input and output ...
Raffle, Hayes Solos, 1974-
mNAL PERFORMANCE REPORT mNAL PERFORMANCE REPORT for INFRARED ABSORPTION SPECTROSCOPY AND CHEMICAL KINETICS OF FREE RADICALS DE-FG05-85ER13439 1-AUG-1985 to 31-JUL-1994 Robert F. Curl and Graham P. Glass Principal Investigators Introduction This research was directed at the detection, monitoring, and study (by infrared absorption spectroscopy) of the chemical kinetic behavior of small free radical species thought to be important intermediates in combustion. The work typically progressed from the detection and analysis of the infrared spectrum of combustion radical to the utilization of the infrared spectrum thus obtained in the investigation of chemical kinetics of the radical species. The methodology employed was infrared kinetic spectroscopy. In this technique the radical is produced by UV flash photolysis using an excimer laser and then
HCCI in a CFR engine: experiments and detailed kinetic modeling
Single cylinder engine experiments and chemical kinetic modeling have been performed to study the effect of variations in fuel, equivalence ratio, and intake charge temperature on the start of combustion and the heat release rate. Neat propane and a fuel blend of 15% dimethyl-ether in methane have been studied. The results demonstrate the role of these parameters on the start of combustion, efficiency, imep, and emissions. Single zone kinetic modeling results show the trends consistent with the experimental results.
Flowers, D; Aceves, S; Smith, R; Torres, J; Girard, J; Dibble, R
Defect aggregation kinetics in calcium fluoride
Defects in solid materials are responsible for many of their most interesting and critical properties. The authors have developed a site-selective laser technique that allows us to monitor the aggregation of rare earth ion defects in solids on the microscopic scale. This excitation absorption laser method enables us to derive kinetic rate information and thermodynamic parameters for the distribution of defects in solids. For doped materials, various types of defects arise when the dopant ions have ionic charges that differ from the charges of host crystal ions. In model systems such as alkaline earth fluorides doped with trivalent rare earth ions, some defect sites consist of a single dopant ion, while others consist of clusters of dopant cations and interstitial anions. Heat treatment of doped samples leads to a distribution of the various types of defect sites that is characteristic of the temperature and length of heat treatment and the total dopant ion concentration. The results from a study of the formation of trivalent europium ion defect aggregates in calcium fluoride indicate that our method successfully monitors changes in individual site concentrations resulting from heat treatment. The results of this study are consistent with the formation of negatively charged dimer and trimer defects in Eu{sup 3+}:CaF{sub 2} crystals from isolated europium ion and (Eu:F{sub i}) single pair defects. In addition, he presents evidence for rapid equilibrium between the isolated ion and the single pair. Other work presented in this thesis includes the development of a high-temperature fluorine oxidation apparatus that was used to convert divalent europium ions to the trivalent state in calcium fluoride single crystals. This apparatus was also used to increase the superconducting {Tc}'s of YBa{sub 2}Cu{sub 3}O{sub 7-x} through modification of copper-oxygen oxidation states.
Cirillo, K.M.
We evaluate the proposed NpO{sub 2}{sup +}(aq)-NpO{sub 2}(cr) reduction-precipitation system at elevated temperatures to obtain primary information on the effects of temperature, ionic strength, O{sub 2} and CO{sub 2}. Experiments conducted on unfiltered solutions at 10{sup -4} M NpO{sub 2}{sup +}(aq), neutral pH, and 200 C indicated that solution colloids strongly affect precipitation kinetics. Subsequent experiments on filtered solutions at 200, 212, and 225 C showed consistent and distinctive temperature-dependent behavior at reaction times {le} 800 hours. At longer times, the 200 C experiments showed unexpected dissolution of neptunium solids, but experiments at 212 C and 225 C demonstrated quasi steady-state neptunium concentrations of 3 x 10{sup -6} M and 6 x 10{sup -6} M, respectively. Solids from a representative experiment analyzed by X-ray diffraction were consistent with NpO{sub 2}(cr). A 200 C experiment with a NaCl concentration of 0.05 M showed a dramatic increase in the rate of neptunium loss. A 200 C experiment in an argon atmosphere resulted in nearly complete loss of aqueous neptunium. Previously proposed NpO{sub 2}{sup +}(aq)-NpO{sub 2}(cr) reduction-precipitation mechanisms in the literature specified a 1:1 ratio of neptunium loss and H{sup +} production in solution over time. However, all experiments demonstrated ratios of approximately 0.4 to 0.5. Carbonate equilibria can account for only about 40% of this discrepancy, leaving an unexpected deficit in H+ production that suggests that additional chemical processes are occurring.
Johnsen, A M; Roberts, K E; Prussin, S G
A Study of Homogeneous Condensation-Freezing Nucleation of Small Water Droplets in an Expansion Cloud Chamber
Observations of the homogeneous nucleation of water vapor in an expansion cloud chamber have been carried out for the temperature range ?50 to +17�C in the carrier gases argon and helium. We have found that the onset of the ice phase in freshly ...
Rodney J. Anderson; Ronald C. Miller; James L. Kassner Jr.; Donald E. Hagen
Tests of Micro-Pattern Gaseous Detectors for Active1 Target Time Projection Chambers in nuclear physics2
Tests of Micro-Pattern Gaseous Detectors for Active1 Target Time Projection Chambers in nuclear the gas used as the detection medium10 is also a target for nuclear reactions, have been used for a wide variety of11 nuclear physics applications since the eighties. Improvements in MPGD (Mi-12 cro Pattern
Recanati, Catherine
Large-eddy simulations of air flow and turbulence within and around low aspect ratio cylindrical open-top chambers
The flow around cylindrical open-top chambers (OTCs) with aspect ratios (i.e., height-to-diameter ratios) much less than unity is investigated using a large-eddy simulation (LES) model. The solid structures are represented using the immersed ...
Philip Cunningham; Rodman R. Linn; Eunmo Koo; Cathy J. Wilson
General Services Administration
The Federal Energy Management Improvement Act of 1988 requires all federal agencies, including the General Services Administration (GSA), to reduce building energy usage by 10 percent from 1985 levels by 1995. While GSA has been actively pursuing energy conservation, it faces a formidable challenge in achieving the required 10-percent building energy reduction by 1995, and it is too early to tell whether GSA's efforts will be successful. Because GSA has developed a comprehensive strategy to reduce building energy usage, has begun funding a variety of specific energy conservation initiatives, and is actively exploring other energy-saving opportunities, this paper makes no recommendations to GSA.
One-dimensional kinetics modifications for BWR reload methods
Yankee Atomic Electric Company (YAEC) currently uses RETRAN-02 to analyze limiting transients and establish operating minimum critical power ratio (MCPR) limits for Vermont Yankee (VY) boiling water reactor (BWR) reload analysis. The US Nuclear Regulatory Commission-approved analysis methods, used in previous cycles, use the point-kinetics modeling option in RETRAN-02 to represent transient-induced neutronic feedback. RETRAN-02 also contains a one-dimensional (1-D) kinetics neutronic feedback model option that provides a more accurate transient power prediction than the point-kinetics model. In the past few fuel cycles, the thermal or MCPR operating margin at VY has eroded due to increases in fuel cycle length. To offset this decrease, YAEC has developed the capability to use the more accurate 1-D kinetics RETRAN option. This paper reviews the qualification effort for the YAEC BWR methods. This paper also presents a comparison between RETRAN-02 predictions using 1-D and point kinetics for the limiting transient, and demonstrates the typical gain in thermal margin from 1-D kinetics.
Chandola, V.; Robichaud, J.D.
Soliton Kinetic Equations with Non-Kolmogorovian Structure: A New Tool for Biological Modeling?
is nonlinear kinetics of a chemical type). Another application is a simple two-qubit system whose evolution-Kolmogorovian aspects of chemical kinetics. Next, we briefly discuss the links between kinetic equations and their Lax equations becomes then especially clear. NON-KOLMOGOROVIAN ASPECTS OF CHEMICAL KINETICS Consider
Aerts, Diederik
Visualizing Chemical Compositions and Kinetics of Sol-Gel by Near-Infrared Multispectral Imaging
Visualizing Chemical Compositions and Kinetics of Sol-Gel by Near-Infrared Multispectral Imaging in order to determine the presence of any chemical and kinetic inhomogeneity. Unfortunately, to date, NIR to determine the chemical and kinetic inho- mogeneity of sol-gel. Preliminary results on the kinetics of sol
Reid, Scott A.
Phase-field Model for Interstitial Loop Growth Kinetics and Thermodynamic and Kinetic Models of Irradiated Fe-Cr Alloys
Microstructure evolution kinetics in irradiated materials has strongly spatial correlation. For example, void and second phases prefer to nucleate and grow at pre-existing defects such as dislocations, grain boundaries, and cracks. Inhomogeneous microstructure evolution results in inhomogeneity of microstructure and thermo-mechanical properties. Therefore, the simulation capability for predicting three dimensional (3-D) microstructure evolution kinetics and its subsequent impact on material properties and performance is crucial for scientific design of advanced nuclear materials and optimal operation conditions in order to reduce uncertainty in operational and safety margins. Very recently the meso-scale phase-field (PF) method has been used to predict gas bubble evolution, void swelling, void lattice formation and void migration in irradiated materials,. Although most results of phase-field simulations are qualitative due to the lake of accurate thermodynamic and kinetic properties of defects, possible missing of important kinetic properties and processes, and the capability of current codes and computers for large time and length scale modeling, the simulations demonstrate that PF method is a promising simulation tool for predicting 3-D heterogeneous microstructure and property evolution, and providing microstructure evolution kinetics for higher scale level simulations of microstructure and property evolution such as mean field methods. This report consists of two parts. In part I, we will present a new phase-field model for predicting interstitial loop growth kinetics in irradiated materials. The effect of defect (vacancy/interstitial) generation, diffusion and recombination, sink strength, long-range elastic interaction, inhomogeneous and anisotropic mobility on microstructure evolution kinetics is taken into account in the model. The model is used to study the effect of elastic interaction on interstitial loop growth kinetics, the interstitial flux, and sink strength of interstitial loop for interstitials. In part II, we present a generic phase field model and discuss the thermodynamic and kinetic properties in phase-field models including the reaction kinetics of radiation defects and local free energy of irradiated materials. In particular, a two-sublattice thermodynamic model is suggested to describe the local free energy of alloys with irradiated defects. Fe-Cr alloy is taken as an example to explain the required thermodynamic and kinetic properties for quantitative phase-field modeling. Finally the great challenges in phase-field modeling will be discussed.
Li, Yulan; Hu, Shenyang Y.; Sun, Xin; Khaleel, Mohammad A.
The Effect of Oxygen to Methane Ratio on the Methane-wet Air Autothermal Reforming and Carbon Deposition in the Micro-chamber
Considering the problems of catalyst carbon deposition and reforming endothermic reaction in micro-reforming chamber, coupled methane catalyst partial oxidation and steam methane reforming can make the micro-reforming system auto-supply heat and inhibit ... Keywords: micro-chamber, autothermal reforming, carbon deposition, oxygen to methane ratio
Ran Jingyu; Tu Weifeng
The Impact of Alternative Fuels on Combustion Kinetics
The research targets the development of detailed kinetic models to quantitatively characterize the impact of alternative fuels on the performance of Navy turbines and diesel engines. Such impacts include kinetic properties such as cetane number, flame speed, and emissions as well as physical properties such as the impact of boiling point distributions on fuel vaporization and mixing. The primary focus will be Fischer-Tropsch liquids made from natural gas, coal or biomass. The models will include both the effects of operation with these alternative fuels as well as blends of these fuels with conventional petroleum-based fuels. The team will develop the requisite kinetic rules for specific reaction types and incorporate these into detailed kinetic mechanisms to predict the combustion performance of neat alternative fuels as well as blends of these fuels with conventional fuels. Reduced kinetic models will be then developed to allow solution of the coupled kinetics/transport problems. This is a collaboration between the Colorado School of Mines (CSM) and the Lawrence Livermore National Laboratory (LLNL). The CSM/LLNL team plans to build on the substantial progress made in recent years in developing accurate detailed chemical mechanisms for the oxidation and pyrolysis of conventional fuels. Particular emphasis will be placed upon reactions of the isoalkanes and the daughter radicals, especially tertiary radicals, formed by abstraction from the isoalkanes. The various components of the program are described. We have been developing the kinetic models for two iso-dodecane molecules, using the same kinetic modeling formalisms that were developed for the gasoline and diesel primary reference fuels. These mechanisms, and the thermochemical and transport coefficient submodels for them, are very close to completion at the time of this report, and we expect them to be available for kinetic simulations early in the coming year. They will provide a basis for prediction and selection of desirable F-T molecules for use in jet engine simulations, where we should be able to predict the ignition, combustion and emissions characteristics of proposed fuel components. These mechanisms include the reactions and chemical species needed to describe high temperature phenomena such as shock tube ignition and flammability behavior, and they will also include low temperature kinetics to describe other ignition phenomena such as compression ignition and knocking. During the past years, our hydrocarbon kinetics modeling group at LLNL has focused a great deal on fuels typical of gasoline and diesel fuel. About 10 years ago, we developed kinetic models for the fuel octane primary reference fuels, n-heptane [1] and iso-octane [2], which have 7 and 8 carbon atoms and are therefore representative of typical gasoline fuels. N-heptane represents the low limit of knock resistance with an octane number of 0, while iso-octane is very knock resistant with an octane number of 100. High knock resistance in iso-octane was attributed largely to the large fraction of primary C-H bonds in the molecule, including 15 of the 18 C-H bonds, and the high bond energy of these primary bonds plays a large role in this knock resistance. In contrast, in the much more ignitable n-heptane, 10 of its 16 C-H bonds are much less strongly bound secondary C-H bonds, leading to its very low octane number. All of these factors, as well as a similarly complex kinetic description of the equally important role of the transition state rings that transfer H atoms within the reacting fuel molecules, were quantified and collected into large kinetic reaction mechanisms that are used by many researchers in the fuel chemistry world.
Ocean General Circulation Models
1. Definition of Subject The purpose of this text is to provide an introduction to aspects of oceanic general circulation models (OGCMs), an important component of Climate System or Earth System Model (ESM). The role of the ocean in ESMs is described in Chapter XX (EDITOR: PLEASE FIND THE COUPLED CLIMATE or EARTH SYSTEM MODELING CHAPTERS). The emerging need for understanding the Earth�s climate system and especially projecting its future evolution has encouraged scientists to explore the dynamical, physical, and biogeochemical processes in the ocean. Understanding the role of these processes in the climate system is an interesting and challenging scientific subject. For example, a research question how much extra heat or CO2 generated by anthropogenic activities can be stored in the deep ocean is not only scientifically interesting but also important in projecting future climate of the earth. Thus, OGCMs have been developed and applied to investigate the various oceanic processes and their role in the climate system.
Yoon, Jin-Ho; Ma, Po-Lun
Generalized Stochastic Gradient Learning
#1;#2;#3;#2;#4;#5;#6;#7;#8;#2; #11;#12; #14;#15;#5;#16;#12;#7;#14; #1;#4;#5; #7;#2;#3;#12; #17;#2;#5;#4;#3;#7;#3;#18; George W. Evans, Seppo Honkapohja and Noah Willams #19;#14;#12; #20;#2;#4; #21;#22;#22;#23; #24;#25;#26;#27; #22;#23;#28;#23; #1... ;#2;#3;#4;#3;#2;#4;#5;#6;#4;#7;#8;#2;#3;#6; #4; #11;#3;#12;#2;#8;#3;#4; #6;#14;#15;#11;#16;#16;#11;#2;#17; Generalized Stochastic Gradient Learning? George W. Evans University of Oregon Seppo Honkapohja University of Cambridge Noah Williams Princeton...
Evans, George W; Honkapohja, Seppo; Williams, Noah
Since last year�s GTC Conference, a considerable number of significant events have occurred in the gasification technology marketplace. New IGCC projects have come on stream with commercial operation, other new IGCC projects have been announced and started in development, environmental issues have gained emphasis, and energy prices, notably natural gas, have escalated dramatically. Directionally, all of these events appear to have created a more favorable atmosphere for IGCC projects. Related to an ongoing IGCC project currently in development, a joint analysis has been performed by Global Energy, General Electric Power Systems, and Praxair to evaluate technical and economic elements for the performance of BGL Gasification Technology based on solid hydrocarbon fuel feed to an IGCC for power generation. Results of the analysis provide a picture of the relative economics in today�s environment for electrical power generation by conventional natural gas fired combined cycle power systems compared to using BGL Gasification Technology in an IGCC configuration. 2
Igcc Power Generation; Richard A. Olliver; John M. Wainwright; Raymond F. Drnevich Abstract
United States Attorney General
93, 5 U.S. Op. Off. Legal Counsel 1, 1981 WL 30865 (U.S.A.G.) 93, 5 U.S. Op. Off. Legal Counsel 1, 1981 WL 30865 (U.S.A.G.) United States Attorney General ***1 *293 January 16, 1981 **1 The President The White House Washington, D.C. 20500 MY DEAR MR. PRESIDENT: You have asked my opinion concerning the scope of currently existing legal and constitutional authorities for the continuance of government functions during a temporary lapse in appropriations, such as the Government sustained on October 1, 1980. As you know, some initial determination concerning the extent of these authorities had to be made in the waning hours of the last fiscal year in order to avoid extreme administrative confusion that might have arisen from Congress' failure timely to enact 11 of the 13 anticipated regular appropriations bills, FN;B1[FN1]FN;F1 or a
DOE HANDBOOK GENERAL EMPLOYEE RADIOLOGICAL TRAINING U.S. Department of Energy AREA TRNG Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Not Measurement Sensitive This document is available on the Department of Energy Technical Standards Program Web Site at http://www.hss.energy.gov/nuclearsafety/techstds/ DOE-HDBK-1131-2007 iii Foreword This Handbook describes an implementation process for core training as recommended in chapter 14, Radiation Safety Training, of Implementation Guide G44.1B, Radiation Protection Programs Guide, and as outlined in the DOE Radiological Control Standard [RCS - DOE-STD-1098-99, Ch. 1]. The Handbook is meant to assist those individuals
Teacher and General Resources
Argonne Argonne Science Project Ideas! Our Teacher and General Resources section provides you with online aids for learning about science, such as a tutorial of science equipment, as well as guides for the metric system. Please select any item below that interests you. Also, if you have an idea for a great teacher resource that we could share, please click our Ideas page. We would love to hear from you! Science Equipment Resources: Online Basic Laboratory Equipment Information An Introduction to Basic Laboratory Equipment All students need to know and understand the function of the equipment that they will be using in the science classroom. This exercise is to help students know a beaker from a bunsen burner! TSwift MB 3200 Microscope Online Tutorial Online Microscope Tutorial
Interpretation of ES, CS, and IOS approximations within a translational-internal coupling scheme. II. Application to atom--diatom kinetic cross sections
ES, CS, and IOS approximations to atom--diatom kinetic cross sections are derived. In doing so, reduced S-matrices in a translational-internal coupling scheme are stressed. This entails the insertion of recently obtained approximate reduced S-matrices in the translational-internal coupling scheme into previously derived general expressions for the kinetic cross sections. Of special interest is the structure (rotational j quantum number dependence) of the kinetic cross sections associated with the Senftleben Beenakker effects and of pure internal state relaxation phenomena. The viscomagnetic effect is used as an illustrative example. It is found in particular that there is a great similarity of structure between the energy sudden (and IOS) approximation and the previously derived distorted wave Born results.
Coombe, D.A.; Snider, R.F.
Advanced radiation techniques for inspection of diesel engine combustion chamber materials components. Final report
Heavy duty truck engines must meet stringent life cycle cost and regulatory requirements. Meeting these requirements has resulted in convergence on 4-stroke 6-in-line, turbocharged, and after-cooled engines with direct-injection combustion systems. These engines provide much higher efficiencies (42%, fuel consumption 200 g/kW-hr) than automotive engines (31%, fuel consumption 270 g/kW-hr), but at higher initial cost. Significant near-term diesel engine improvements are necessary and are spurred by continuing competitive, Middle - East oil problems and Congressional legislation. As a result of these trends and pressures, Caterpillar has been actively pursuing a low-fuel consumption engine research program with emphasis on product quality through process control and product inspection. The goal of this project is to combine the nondestructive evaluation and computational resources and expertise available at LLNL with the diesel engine and manufacturing expertise of the Caterpillar Corporation to develop in-process monitoring and inspection techniques for diesel engine combustion chamber components and materials. Early development of these techniques will assure the optimization of the manufacturing process by design/inspection interface. The transition from the development stage to the manufacturing stage requires a both a thorough understanding of the processes and a way of verifying conformance to process standards. NDE is one of the essential tools in accomplishing both elements and in this project will be integrated with Caterpillar`s technological and manufacturing expertise to accomplish the project goals.
Performance of a Drift Chamber Candidate for a Cosmic Muon Tomography System
In the last decade, many groups around the world have been exploring different ways to probe transport containers which may contain illicit Special Nuclear Materials such as uranium. The muon tomography technique has been proposed as a cost effective system with an acceptable accuracy. A group of Canadian institutions (see above), funded by Defence Research and Development Canada, is testing different technologies to track the cosmic muons. One candidate is the single wire Drift Chamber. With the capability of a 2D impact position measurement, two detectors will be placed above and two below the object to be probed. In order to achieve a good 3D image quality of the cargo content, a good angular resolution is required. The simulation showed that 1mrad was required implying the spatial resolution of the trackers must be in the range of 1 to 2 mm for 1 m separation. A tracking system using three prototypes has been built and tested. The spatial resolution obtained is 1.7 mm perpendicular to the wire and 3 mm along the wire.
Anghel, V.; Jewett, C.; Jonkmans, G.; Thompson, M. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Armitage, J.; Botte, J.; Boudjemline, K.; Erlandson, A.; Oakham, G. [Ottawa-Carleton Institute for Physics, Department of Physics, Carleton University, Ottawa, Ontario (Canada); Bueno, J.; Bryman, D.; Liu, Z. [Advanced Applied Physics Solutions, Vancouver, British Columbia (Canada); Charles, E.; Gallant, G. [Canada Border Services Agency, Ottawa, Ontario (Canada); Cousins, T.; Noel, S. [International Safety Research, Ottawa, Ontario (Canada); Drouin, P.-L.; Waller, D. [Defence Research and Development Canada, Ottawa, Ontario (Canada); Stocki, T. J. [Health Canada, Ottawa, Ontario (Canada)
Kinetic and Prediction of Hydrogen Outgassing from Lithium Hydride
In most industrial or device applications, LiH is placed in either an initially dry or a vacuum environment with other materials that may release moisture slowly over many months, years, or even decades. In such instances, the rate of hydrogen outgassing from the reaction of LiH with H{sub 2}O can be reasonably approximated by the rate at which H{sub 2}O is released from the moisture containing materials. In a vacuum or dry environment, LiOH decomposes slowly with time into Li{sub 2}O even at room temperature according to: 2LiOH(s) {yields} Li{sub 2}O(s) + H{sub 2}O(g) (1). The kinetics of the decomposition of LiOH depends on the dryness/vacuum level and temperature. It was discovered by different workers that vacuum thermal decomposition of bulk LiOH powder (grain sizes on the order of tens to hundreds of micrometers) into Li{sub 2}O follows a reaction front moving from the surface inward. Due to stress at the LiOH/vacuum interface and defective and missing crystalline bonding at surface sites, lattice vibrations at the surfaces/interfaces of most materials are at frequencies different than those in the bulk, a phenomenon observed in most solids. The chemical reactivity and electronic properties at surfaces and interfaces of materials are also different than those in the bulk. It is, therefore, expected that the amount of energy required to break bonds at the LiOH/vacuum interface is not as large as in the bulk. In addition, in an environment where there is a moisture sink or in the case of a continuously pumped vacuum chamber, H{sub 2}O vapor is continuously removed and LiOH decomposes into Li{sub 2}O from the LiOH/vacuum interface (where it is thermally less stable) inward according to reaction (1) in an effort to maintain the equilibrium H{sub 2}O vapor pressure at the sample/vacuum interface. In a closed system containing both LiH and LiOH, the H{sub 2}O released from the decomposition of LiOH reacts with LiH to form hydrogen gas according to the following reaction: 2LiH(s) + H{sub 2}O(g) {yields} Li{sub 2}O(s) +2H{sub 2}(g) + heat (2). Such is the case of vacuum thermal decomposition of a corrosion layer previously grown on top of a LiH substrate. Here, the huge H{sub 2}O concentration gradient across the Li{sub 2}O buffer layer in between the hydrophilic LiH substrate and LiOH, coupled with the defective nature of LiOH at surfaces/interfaces as discussed above, effectively lowers the energy barrier for LiOH decomposition here in comparison with bulk LiOH and turns the LiH substrate into an effective moisture pump. As a result, in the case of vacuum thermal decomposition of LiOH on top of a LiH substrate, the LiOH decomposition front starts at the LiH/Li{sub 2}O/LiOH interface. As a function of increasing time and temperature, the Li{sub 2}O layer in between LiH and LiOH gets thicker, causing the energy barrier for the LiOH decomposition at the LiOH/Li{sub 2}O/LiH interface to increase, and eventually LiOH at the LiOH/vacuum interface also starts to decompose into Li{sub 2}O for reasons described in the previous paragraph. Thereafter, the Li{sub 2}O fronts keep moving inward from all directions until all the LiOH is gone. This vacuum thermal decomposition process of LiOH previously grown on top of a LiH substrate is illustrated in the cartoon of figure 1.
Dinh, L N; Schildbach, M A; Smith, R A; Balazs, B; McLean II, W
Determination of kinetic coefficients for the simultaneous reduction of sulfate and uranium by Desulfovibrio desulfuricans bacteria
Uranium contamination of groundwaters and surface waters near abandoned mill tailings piles is a serious concern in many areas of the western United States. Uranium usually exists in either the U(IV) or the U(VI) oxidation state. U(VI) is soluble in water and, as a result, is very mobile in the environment. U(IV), however, is generally insoluble in water and, therefore, is not subject to aqueous transport. In recent years, researchers have discovered that certain anaerobic microorganisms, such as the sulfate-reducing bacteria Desulfovibrio desulfuricans, can mediate the reduction of U(VI) to U(IV). Although the ability of this microorganism to reduce U(VI) has been studied in some detail by previous researchers, the kinetics of the reactions have not been characterized. The purpose of this research was to perform kinetic studies on Desulfovibrio desulficans bacteria during simultaneous reduction of sulfate and uranium and to determine the phase in which uranium exists after it has been reduced and precipitated from solution. The studies were conducted in a laboratory-scale chemostat under substrate-limited growth conditions with pyruvate as the substrate. Kinetic coefficients for substrate utilization and cell growth were calculated using the Monod equation. The maximum rate of substrate utilization (k) was determined to be 4.70 days{sup {minus}1} while the half-velocity constant (K{sub s}) was 140 mg/l COD. The yield coefficient (Y) was determined to be 0.17 mg cells/mg COD while the endogenous decay coefficient (k{sub d}) was calculated as 0.072 days{sup {minus}1}. After reduction, U(IV) Precipitated from solution in the uraninite (UO{sub 2}) phase. Uranium removal efficiency as high as 90% was achieved in the chemostat.
Tucker, M.D.
Kinetic dispersion of Langmuir waves. I. The Langmuir decay instability
We derive a fully kinetic, three-dimensional dispersion relation for Langmuir waves with a focus on the Langmuir decay instability (LDI). The kinetic dispersion is compared to the standard fluid dispersion found with an equation of state (EOS) closure. The EOS closure fails to capture the intricacies of the nonlinear pressure when high frequency electron plasma waves (EPWs) couple to low frequency ion acoustic waves (IAWs). In particular, we find discrepancies in the k{lambda}{sub d} scaling of the LDI growth rate, where k is the wavenumber of the incident EPW and {lambda}{sub d} is the Debye length. As a result, the kinetic dispersion relation for LDI results in instability thresholds that can be in excess of twice those predicted by the fluid theory. Both the fluid and kinetic dispersion relations predict a nonlinear frequency shift due to the beating of the pump and scattered EPWs, but again the k{lambda}{sub d} scaling of these frequency shifts differ. In addition, the kinetic dispersion predicts a nonlinear reduction in the IAW damping from the three-wave interaction.
Palastro, J. P.; Williams, E. A.; Hinkel, D. E.; Divol, L.; Strozzi, D. J. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)
PKS 1018-42: A Powerful Kinetically Dominated Quasar
We have identified PKS 1018-42 as a radio galaxy with extraordinarily powerful jets, over twice as powerful as any 3CR source of equal or lesser redshift except for one (3C196). It is perhaps the most intrinsically powerful extragalactic radio source in the, still poorly explored, Southern Hemisphere. PKS 1018-42 belongs to the class of FR II objects that are kinetically dominated, the jet kinetic luminosity, $Q \\sim 6.5 \\times 10^{46}\\mathrm{ergs/s}$ (calculated at 151 MHz), is 3.4 times larger than the total thermal luminosity (IR to X-ray) of the accretion flow, $L_{bol} \\sim 1.9 \\times 10^{46}\\mathrm{ergs/s}$. It is the fourth most kinetically dominated quasar that we could verify from existing radio data. From a review of the literature, we find that kinetically dominated sources such as PKS 1018-42 are rare, and list the 5 most kinetically dominated sources found from our review. Our results for PKS 1018-42 are based on new observations from the Australia Telescope Compact Array.
Brian Punsly; Steven Tingay
Kinetic extruder - a dry pulverized solid material pump
Method and apparatus are shown for the continuous feeding of pulverized material to a high pressure container. A rotor is located within the high pressure container. The pulverized material is fed from a feed hopper through a stationary feed pipe to a vented spin-up chamber to a plurality of two-stage sprues mounted in the rotor. Control nozzles downstream from the sprues meter the flow of coal through the sprues.
Meyer, John W. (Palo Alto, CA); Bonin, John H. (Sunnyvale, CA); Daniel, Jr., Arnold D. (Pleasanton, CA)
Method and apparatus are shown for the continuous feeding of pulverized material to a high pressure container. A rotor is located within the high pressure container. The pulverized material is fed from a feed hopper through a stationary feed pipe to a vented spin-up chamber to a plurality of two-stage sprues mounted in the rotor. Control nozzles downstream from the sprues meter the flow of coal through the sprues. 19 figs.
Meyer, J.W.; Bonin, J.H.; Daniel, A.D. Jr.
Isobutane ignition delay time measurements at high pressure and detailed chemical kinetic simulations
Rapid compression machine and shock-tube ignition experiments were performed for real fuel/air isobutane mixtures at equivalence ratios of 0.3, 0.5, 1, and 2. The wide range of experimental conditions included temperatures from 590 to 1567 K at pressures of approximately 1, 10, 20, and 30 atm. These data represent the most comprehensive set of experiments currently available for isobutane oxidation and further accentuate the complementary attributes of the two techniques toward high-pressure oxidation experiments over a wide range of temperatures. The experimental results were used to validate a detailed chemical kinetic model composed of 1328 reactions involving 230 species. This mechanism has been successfully used to simulate previously published ignition delay times as well. A thorough sensitivity analysis was performed to gain further insight to the chemical processes occurring at various conditions. Additionally, useful ignition delay time correlations were developed for temperatures greater than 1025 K. Comparisons are also made with available isobutane data from the literature, as well as with 100% n-butane and 50-50% n-butane-isobutane mixtures in air that were presented by the authors in recent studies. In general, the kinetic model shows excellent agreement with the data over the wide range of conditions of the present study. (author)
Healy, D.; Curran, H.J. [Combustion Chemistry Centre, School of Chemistry, NUI Galway (Ireland); Donato, N.S.; Aul, C.J.; Petersen, E.L. [Department of Mechanical Engineering, Texas A and M University, College Station, TX (United States); Zinner, C.M. [Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL (United States); Bourque, G. [Rolls-Royce Canada Limited, 9500 Cote de Liesse, Lachine, Quebec (Canada)
Kinetics of Mismatch Formation opposite Lesions by the Replicative DNA Polymerase from Bacteriophage RB69
The fidelity of DNA replication is under constant threat from the formation of lesions within the genome. Oxidation of DNA bases leads to the formation of altered DNA bases such as 8-oxo-7,8-dihydroguanine, commonly called 8-oxoG, and 2-hydroxyadenenine, or 2-OHA. In this work we have examined the incorporation kinetics opposite these two oxidatively derived lesions as well as an abasic site analogue by the replicative DNA polymerase from bacteriophage RB69. We compared the kinetic parameters for both wild type and the low fidelity L561A variant. While nucleotide incorporation rates (k{sub pol}) were generally higher for the variant, the presence of a lesion in the templating position reduced the ability of both the wild-type and variant DNA polymerases to form ternary enzyme-DNA-dNTP complexes. Thus, the L561A substitution does not significantly affect the ability of the RB69 DNA polymerase to recognize damaged DNA; instead, the mutation increases the probability that nucleotide incorporation will occur. We have also solved the crystal structure of the L561A variant forming an 8-oxoG {center_dot} dATP mispair and show that the propensity for forming this mispair depends on an enlarged polymerase active site.
Hogg, Matthew; Rudnicki, Jean; Midkiff, John; Reha-Krantz, Linda; Doubli, Sylvie; Wallace, Susan S. (Alberta); (Vermont)
Deuterium isotope effects during HMX combustion: Chemical kinetic burn-rate control mechanism verified
The appearance of a significant deuterium isotope effect during the combustion of the solid HMX compound verifies that the chemical reaction kinetics is a major contributor in determining the experimentally observed or global burn rate. Burn rate comparison of HMX and its deuterium labeled HMX-d(8) analogue reveals a primary kinetic deuterium isotope effect (1 deg. KDIE) at 500 psig (3.55 MPa) and 1000 psig (6.99 MPa) pressure and selectively identifies covalent carbon-hydrogen bond rupture as the mechanistic step which ultimately controls the further HMX burn rate under the static combustion conditions of this experiment. The 1 deg. KDIE value further suggests the rate-limiting C-H bond rupture occurs during the solid state HMX decomposition/deflagration portion of the overall combustion event and is supported by other independently published studies. A possible anomalous KDIE result at 1500 psig (10.4 MPa) is addressed. This condensed phase KDIE approach illustrates a direct link between lower temperature/pressure thermal decomposition and deflagration processes and their potential applicability to the combustion regime. Most importantly, a new general method is demonstrated for mechanistic combustion investigations which selectively permits an in-situ identification of the compound's burn rate-controlling step.
Shackelford, S.A.; Goshgarian, B.B.; Chapman, R.D.; Askins, R.E.; Flanigan, D.A.
Kinetics of heterogeneous nucleation in supersaturated vapor: Fundamental limits to neutral particle detection revisited
We examine the nucleated (with barrier) activation of perfectly wetting (zero contact angle) particles ranging from essentially bulk size down to approximately 1-nm mass diameter. While similar studies trace back to the pioneering work of Fletcher, we present here a novel approach to the analysis based on general area constructions that enable key thermodynamic properties, including surface and bulk contributions to nucleation work, to be interpreted geometrically with reference to the Kelvin curve. The kinetics of activation are described in more detail in terms of the mean first passage time (MFPT) for barrier crossing. MFPT theory and benchmark calculations are used to develop and test a new approximate-but-simpler-to-use analytic expression for the barrier crossing rate. The present study is motivated by recent condensation particle counter (CPC) studies that appear to finally establish the long-predicted detection of 'sub-Kelvin' particles in the nano-size regime. Corresponding states thermodynamic and kinetic scaling approaches are used to facilitate the correlation and selection of optimal CPC working fluids and operating conditions based on a new metric for heterogeneous nucleation, the signal-to-noise ratio, and physical and chemical properties.
McGraw R.; Wang, J.; Kuang, C.
Forward Drift Chamber for the GlueX Experiment at the 12 GeV CEBAF Machine
The GlueX experiment will search for exotic mesons produced by 9 GeV linearly polarized photons from the upgraded CEBAF machine. It is critical to detect and measure the four-momenta of all the charged particles and photons resulting from the decays of the mesons. The solenoid-based detector system includes tracking detectors and calorimeters. The Forward Drift Chamber, FDC, consists of 24 circular planar drift chambers of 1m diameter. Additional cathode readout is required to achieve efficient pattern recognition. The detection of photons by the electromagnetic calorimeters imposes constraints on the amount of material used in the FDC. The specific features of the detector and the readout electronics will be described. Results from the tests of the full scale prototype will be presented, as well.
Pentchev, Lubomir; Zihlmann, Benedikt [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA 23606 (United States)
Forward Drift Chamber for the GlueX experiment at the 12 GeV CEBAF machine
The GlueX experiment will search for exotic mesons produced by 9 GeV linearly polarized photons from the upgraded CEBAF machine. It is critical to detect and measure the four-momenta of all the charged particles and photons resulting from the decays of the mesons. The solenoid-based detector system includes tracking detectors and calorimeters. The Forward Drift Chamber, FDC, consists of 24 circular planar drift chambers of 1m diameter. Additional cathode readout is required to achieve efficient pattern recognition. The detection of low energy photons by the electromagnetic calorimeters imposes constraints on the amount of material used in the FDC. The specific features of the detector and the readout electronics will be described. Results from the tests of the full scale prototype will be presented, as well.
Lubomir Pentchev, Benedikt Zihlmann
A Measurement of the holographic minimum observable beam branching ratio in the Fermilab 15-foot bubble chamber
Holography has been used successfully in combination with conventional optics for the first time in a large cryogenic bubble chamber, the 15-Foot Bubble Chamber at Fermilab, during a physics run. The innovative system combined the reference beam with the object beam, illuminating a conical volume of {approx} 1.4 m{sup 3}. Bubble tracks from neutrino interactions with a width of {approx} 120 {micro}m have been recorded with good contrast. The ratio of intensities of the object light to the reference light striking the film is called the Beam Branching Ratio. We obtained in our experiment an exceedingly small minimum-observable ratio of (0.54 {+-} 0.21) x 10{sup -7}. The technology has the potential for a wide range of applications.
Aderholz, M.; Aggarwal, M.M.; Akbari, H.; Allport, P.P.; Badyal, S.K.; Ballagh, H.C.; Barth, M.; Baton, J.P.; Bingham, H.H.; Bjelkhagen, H.; Brucker, E.B.; Burnstein, R.A.; Campbell, J.R.; Cence, R.J.; Chatterjee, T.K.; Clayton, E.F.; Corrigan, G.; Coutures, C.; DeProspo, D.; Devanand,; De Wolf, E.A.; /UC, Berkeley /Birmingham U. /Brussels U., IIHE /CERN /Punjab U. /Fermilab /Hawaii U. /Imperial Coll., London /IIT, Chicago /Jammu U. /Munich, Max Planck Inst. /Oxford U. /Rutgers U., Piscataway /Rutherford /DAPNIA, Saclay /Stevens Tech. /Tufts U.
Hydrocarbon-fuel/combustion-chamber-liner materials compatibility. Interim final report, 7 November 1986-31 October 1989
Results of material compatibility experiments using hydrocarbon fuels in contact with copper-based combustion chamber liner materials are presented. Mil-Spec RP-1, n- dodecane, propane, and methane fuels were tested in contact with OFHC, NASA-Z, and ZrCu coppers. Two distinct test methods were employed. Static tests, in which copper coupons were exposed to fuel for long durations at constant temperature and pressure, provided compatibility data in a precisely controlled environment. Dynamic tests, using the Aerojet Carbothermal Test Facility, provided fuel and copper compatibility data under realistic booster engine service conditions. Tests were conducted using very pure grades of each fuel and fuels to which a contaminant, e.g., ethylene or methyl mercaptan, was added to define the role played by fuel impurities. Conclusions are reached as to degradation mechanisms and effects, methods for the elimination of these mechanisms, selection of copper alloy combustion chamber liners, and hydrocarbon fuel purchase specifications.
Gage, M.L.
NETL: Mercury Emissions Control Technologies - Bench Scale Kinetics of
Bench Scale Kinetics of Mercury Reactions in FGD Liquors Bench Scale Kinetics of Mercury Reactions in FGD Liquors When research into the measurement and control of Hg emissions from coal-fired power plants began in earnest in the early 1990s, it was observed that oxidized mercury can be scrubbed at high efficiency in wet FGD systems, while elemental mercury can not. In many cases, elemental mercury concentrations were observed to increase slightly across wet FGD systems, but this was typically regarded as within the variability of the measurement methods. However, later measurements have shown substantial re-emissions from some FGD systems. The goal of this project is to develop a fundamental understanding of the aqueous chemistry of mercury (Hg) absorbed by wet flue gas desulfurization (FGD) scrubbing liquors. Specifically, the project will determine the chemical reactions that oxidized mercury undergoes once absorbed, the byproducts of those reactions, and reaction kinetics.
Amber Kinetics, Inc. Smart Grid Demonstration Project | Open Energy
Kinetics, Inc. Smart Grid Demonstration Project Kinetics, Inc. Smart Grid Demonstration Project Jump to: navigation, search Project Lead Amber Kinetics, Inc. Country United States Headquarters Location Fremont, California Recovery Act Funding $4,000,000.00 Total Project Value $10,000,000.00 Coordinates 37.5482697°, -121.9885719° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[]}
On kinetic description of electromagnetic processes in a quantum plasma
A nonlinear kinetic equation for nonrelativistic quantum plasma with electromagnetic interaction of particles is obtained in the Hartree's mean-field approximation. It is cast in a convenient form of Vlasov-Boltzmann-type equation with "quantum interference integral", that allows for relatively straightforward modification of existing classical Vlasov codes to incorporate quantum effects (quantum statistics and quantum interference of overlapping particles wave functions), without changing the bulk of the codes. Such modification (upgrade) of existing Vlasov codes may provide a direct and effective path to numerical simulations of nonlinear electrostatic and electromagnetic phenomena in quantum plasmas, especially of processes where kinetic effects are important (e.g., modulational interactions and stimulated scattering phenomena involving plasma modes at short wavelengths or high-order kinetic modes, dynamical screening and interaction of charges in quantum plasma, etc.) Moreover, numerical approaches involv...
Tyshetskiy, Y O; Kompaneets, R
Chemical Kinetic Models for HCCI and Diesel Combustion
Predictive engine simulation models are needed to make rapid progress towards DOE's goals of increasing combustion engine efficiency and reducing pollutant emissions. These engine simulation models require chemical kinetic submodels to allow the prediction of the effect of fuel composition on engine performance and emissions. Chemical kinetic models for conventional and next-generation transportation fuels need to be developed so that engine simulation tools can predict fuel effects. The objectives are to: (1) Develop detailed chemical kinetic models for fuel components used in surrogate fuels for diesel and HCCI engines; (2) Develop surrogate fuel models to represent real fuels and model low temperature combustion strategies in HCCI and diesel engines that lead to low emissions and high efficiency; and (3) Characterize the role of fuel composition on low temperature combustion modes of advanced combustion engines.
Pitz, W J; Westbrook, C K; Mehl, M; Sarathy, S M
Kinetic Alfven double layer formed by electron viscosity
The effect of the electron viscosity on the kinetic Alfven solitary wave is investigated. It is found that small electron viscosity changes the electron motion along the magnetic field producing a boundary layer, and thus that in a low beta electron-ion plasma({beta} Much-Less-Than m{sub e}/m{sub i}), an obliquely propagating kinetic solitary Alfven wave can become a double layer. This double layer can exist in the sub-Alfvenic and super-Alfvenic regimes. The length scale of density drop for this double layer is on the order of that of the conventional kinetic solitary Alfven wave, and thus this double layer can accelerate electrons on a very short length scale.
Woo, M. H.; Ryu, C.-M. [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Choi, C. R. [Department of Physics, Korea Advanced Institute of Science and Technology, Taejon 305-701 (Korea, Republic of)
Faculty of Science General Science
Faculty of Science General Science The General Science program gives you maximum flexibility to explore the sciences, plus the core requirements you need for on-going, specialized studies. www.uwindsor.ca/science Rigorous, Enriching Programs The BSc General Science program is a great way to explore your many interests
Scintillation counter and wire chamber front end modules for high energy physics experiments
This document describes two front-end modules developed for the proposed MIPP upgrade (P-960) experiment at Fermilab. The scintillation counter module was developed for the Plastic Ball detector time and charge measurements. The module has eight LEMO 00 input connectors terminated with 50 ohms and accepts negative photomultiplier signals in the range 0.25...1000 pC with the maximum input voltage of 4.0 V. Each input has a passive splitter with integration and differentiation times of {approx}20 ns. The integrated portion of the signal is digitized at 26.55 MHz by Analog Devices AD9229 12-bit pipelined 4-channel ADC. The differentiated signal is discriminated for time measurement and sent to one of the four TMC304 inputs. The 4-channel TMC304 chip allows high precision time measurement of rising and falling edges with {approx}100 ps resolution and has internal digital pipeline. The ADC data is also pipelined which allows deadtime-less operation with trigger decision times of {approx}4 {micro}s. The wire chamber module was developed for MIPP EMCal detector charge measurements. The 32-channel digitizer accepts differential analog signals from four 8-channel integrating wire amplifiers. The connection between wire amplifier and digitizer is provided via 26-wire twist-n-flat cable. The wire amplifier integrates input wire current and has sensitivity of 275 mV/pC and the noise level of {approx}0.013 pC. The digitizer uses the same 12-bit AD9229 ADC chip as the scintillator counter module. The wire amplifier has a built-in test pulser with a mask register to provide testing of the individual channels. Both modules are implemented as a 6Ux220 mm VME size board with 48-pin power connector. A custom europack (VME) 21-slot crate is developed for housing these front-end modules.
Baldin, Boris; DalMonte, Lou; /Fermilab
During the acceleration cycle of the AGS synchrotron, eddy currents are generated within the walls of the vacuum chambers of the AGS main magnets. The vacuum chambers have elliptical cross section, are made of inconel material with a wall thickness of 2 mm and are placed within the gap of the combined-function main magnets of the AGS synchrotron. The generation of the eddy currents in the walls of the vacuum chambers, creates various magnetic multipoles, which affect the optics of the AGS machine. In this report these magnetic multipoles are calculated for various time interval starting at the acceleration cycle, where the magnetic field of the main magnet is {approx}0.1 T, and ending before the beam extraction process, where the magnetic field of the main magnet is almost constant at {approx}1.1 T. The calculations show that the magnetic multipoles generated by the eddy-currents affect the optics of the AGS synchrotron during the acceleration cycle and in particular at low magnetic fields of the main magnet. Their effect is too weak to affect the optics of the AGS machine during beam extraction at the nominal energies.
Chemical and kinetic equilibrations via radiative parton transport
A hot and dense partonic system can be produced in the early stage of a relativistic heavy ion collision. How it equilibrates is important for the extraction of Quark-Gluon Plasma properties. We study the chemical and kinetic equilibrations of the Quark-Gluon Plasma using a radiative transport model. Thermal and Color-Glass-Condensate motivated initial conditions are used. We observe that screened parton interactions always lead to partial pressure isotropization. Different initial pressure anisotropies result in the same asymptotic evolution. Comparison of evolutions with and without radiative processes shows that chemical equilibration interacts with kinetic equilibration and radiative processes can contribute significantly to pressure isotropization.
Bin Zhang; Warner A. Wortman
Detailed chemical kinetic modeling of diesel combustion with oxygenated fuels
The influence of oxygenated hydrocarbons as additives to diesel fuels on ignition, NOx emissions and soot production has been examined using a detailed chemical kinetic reaction mechanism. N-heptane was used as a representative diesel fuel, and methanol, ethanol, dimethyl ether and dimethoxymethane were used as oxygenated fuel additives. It was found that addition of oxygenated hydrocarbons reduced NOx levels and reduced the production of soot precursors. When the overall oxygen content in the fuel reached approximately 25% by mass, production of soot precursors fell effectively to zero, in agreement with experimental studies. The kinetic factors responsible for these observations are discussed.
Pitz, W J; Curran, H J; Fisher, E; Glaude, P A; Marinov, N M; Westbrook, C K
Kinetic description of electron plasma waves with orbital angular momentum
We describe the kinetic theory of electron plasma waves with orbital angular momentum or twisted plasmons. The conditions for a twisted Landau resonance to exist are established, and this concept is introduced for the first time. Expressions for the kinetic dispersion relation and for the electron Landau damping are derived. The particular case of a Maxwellian plasma is examined in detail. The new contributions to wave dispersion and damping due the orbital angular momentum are discussed. It is shown that twisted plasmons can be excited by rotating electron beams.
Mendonca, J. T. [IPFN, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal)
Plasma outflow from a corrugated trap in the kinetic regime
The problem of stationary plasma outflow from an open corrugated trap in the kinetic regime is considered with allowance for pair collisions in the framework of a kinetic equation with the Landau collision integral. The distribution function is studied in the limit of small-scale corrugation and a large mirror ratio. In considering a single corrugation cell, a correction for the distribution function is calculated analytically. An equation describing variations of the distribution function along the system is derived and used to study the problem of plasma outflow into vacuum.
Skovorodin, D. I.; Beklemishev, A. D. [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)
Kinetic energy principle and neoclassical toroidal torque in tokamaks
It is shown that when tokamaks are perturbed, the kinetic energy principle is closely related to the neoclassical toroidal torque by the action invariance of particles. Especially when tokamaks are perturbed from scalar pressure equilibria, the imaginary part of the potential energy in the kinetic energy principle is equivalent to the toroidal torque by the neoclassical toroidal viscosity. A unified description therefore should be made for both physics. It is also shown in this case that the potential energy operator can be self-adjoint and thus the stability calculation can be simplified by minimizing the potential energy.
Park, Jong-Kyu [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)
Kinetic Energy Principle And Neoclassical Toroidal Torque In Tokamaks
It is shown that when tokamaks are perturbed the kinetic energy principle is closely related to the neoclassical toroidal torque by the action invariance of particles. Especially when tokamaks are perturbed from scalar pressure equilibria, the imaginary part of the potential energy in the kinetic energy principle is equivalent to the toroidal torque by the Neoclassical Toroidal Viscosity (NTV). A unified description therefore should be made for both physics. It is also shown in this case that the potential energy operator can be self-adjoint and thus the stability calculation can be simplified by minimizing the potential energy
Jong-Kyu Park
Fragmentation of water by ion impact: Kinetic energy release spectra
The fragmentation of isolated water molecules on collision with 450-keV Ar{sup 9+} has been studied using time-of-flight mass spectrometry employing multihit detection. The kinetic energy release spectrum for the dissociation of [H{sub 2}O]{sup 2+ White-Star} into (H{sup White-Star },H{sup +},O{sup +}) fragments has been measured where H{sup White-Star} is a neutral Rydberg hydrogen atom. Ab initio calculations are carried out for the lowest states of [H{sub 2}O]{sup q+} with q=2 and 3 to help interpret the kinetic energy release spectra.
Rajput, Jyoti; Safvan, C. P. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)
Recent advances in the kinetics of oxygen reduction
Oxygen reduction is considered an important electrocatalytic reaction; the most notable need remains improvement of the catalytic activity of existing metal electrocatalysts and development of new ones. A review is given of new advances in the understanding of reaction kinetics and improvements of the electrocatalytic properties of some surfaces, with focus on recent studies of relationship of the surface properties to its activity and reaction kinetics. The urgent need is to improve catalytic activity of Pt and synthesize new, possibly non- noble metal catalysts. New experimental techniques for obtaining new level of information include various {ital in situ} spectroscopies and scanning probes, some involving synchrotron radiation. 138 refs, 18 figs, 2 tabs.
Adzic, R.
Inspector General Activities and Procedures
o Clarifies the role of all inspectors general in conducting inspections of government-owned quarters and housing facilities for recovering Servicemembers (para 1-4b(3)(b)). o Provides guidance on inspector general office space (para 1-6k). o Provides guidance on the responsibilities of former inspectors general, and authorizes assistant inspectors general to lead inspections (paras 1-12g(5) and 2-2d(1)). o Expands guidance on curtailments and removal from inspector general duty (para 2-5b). o Updates inspector general duty restrictions (para 2-7). o Updates guidance on submitting Freedom of Information Act requests to the Department of the Army�s Records Release Office (para 3-4c(4)). o Adds guidance on releasing inspector general information to the Army staff
Quantitative perturbative study of convergence to equilibrium for collisional kinetic models in the torus
For a general class of linear collisional kinetic models in the torus, including in particular the linearized Boltzmann equation for hard spheres, the linearized Landau equation with hard and moderately soft potentials and the semi-classical linearized fermionic and bosonic relaxation models, we prove explicit coercivity estimates on the associated integro-differential operator for some modified Sobolev norms. We deduce existence of classical solutions near equilibrium for the full non-linear models associated, with explicit regularity bounds, and we obtain explicit estimates on the rate of exponential convergence towards equilibrium in this perturbative setting. The proof are based on a linear energy method which combines the coercivity property of the collision operator in the velocity space with transport effects, in order to deduce coercivity estimates in the whole phase space.
Cl�ment Mouhot; Lukas Neumann
Time-resolved broadband cavity-enhanced absorption spectroscopy for chemical kinetics.
Experimental measurements of elementary reaction rate coefficients and product branching ratios are essential to our understanding of many fundamentally important processes in Combustion Chemistry. However, such measurements are often impossible because of a lack of adequate detection techniques. Some of the largest gaps in our knowledge concern some of the most important radical species, because their short lifetimes and low steady-state concentrations make them particularly difficult to detect. To address this challenge, we propose a novel general detection method for gas-phase chemical kinetics: time-resolved broadband cavity-enhanced absorption spectroscopy (TR-BB-CEAS). This all-optical, non-intrusive, multiplexed method enables sensitive direct probing of transient reaction intermediates in a simple, inexpensive, and robust experimental package.
Sheps, Leonid; Chandler, David W.
Kinetic resonance damping rate of the toroidal ion temperature gradient mode
The linear damping rates of the toroidal ion temperature gradient ({eta}{sub i}) mode due to the toroidal resonance are calculated in the local kinetic limit. The well-known Landau contour method is generalized to treat the analytic continuation problem of the guiding center dispersion function in the toroidal resonance system where the resonance occurs from both the magnetic {Delta}B-curvature drift and the parallel ion transit drift. A detailed numerical analysis is presented for the dependence of the damping rate of the toroidal {eta}{sub i} mode on various parameters such as {var_epsilon}{sub n}, {kappa}{sub y}, and the trapped electron fraction. In addition, a consideration is presented on the decay problem of the ballistic response by the phase mixing in the toroidal system, which is directly related to the present damping problem of the wave normal modes by the toroidal resonance.
Kim, J.Y.; Kishimoto, Y.; Horton, W.; Tajima, T.
Airfoil sampling of a pulsed Laval beam with tunable vacuum ultraviolet (VUV) synchrotron ionization quadrupole mass spectrometry: Application to low--temperature kinetics and product detection
flows suitable for kinetic studies of chemical reactions infor a chemical reaction in the available kinetic window ofa complex kinetic behavior. The rate of chemical reactions
Soorkia, Satchin
Blood meal host preferences of Culex salinarius Coquillett (Diptera : culicidae) in Chambers County, Texas
Bloodmeal host preferences were assessed for Culex salinarius populations occurring along the upper Gulf Coast region of East Texas. Over a one-year period beginning in September 1991, blood-engorged female Cx. salinarius specimens were collected on a monthly basis from three field sites in Chambers County, TX. The source of blood contained in each specimen was determined using a modified precipitin test. The results were used to calculate seasonal foraging ratios for mosquito populations sampled at each site. No noticeable changes in bloodmeal host preferences occurred for Cx. salinarius populations sampled at the coastal marsh site during the study period. Mammals were the primary sources of bloodmeals for these populations, with most mosquitoes collected having fed on cattle. There was an increase in specimens testing positive for avian blood during winter (Dec.-Feb.) commensurate with the arrival of migratory goose populations in the vicinity. The overall foraging ratio, however, did not change. Culex salinarius populations sampled at the upper marsh site also demonstrated a preference for mammalian blood throughout the year. However, forage ratios indicated these populations varied in the mammals upon which they fed, with a number of specimens having fed on armadillos. Cx. salinarius populations sampled at the up-county site demonstrated greater tendency to select birds as bloodmeal sources. Mosquito specimens at this site tested positive for either passeriiform or ciconiiform birds, with a few specimens testing positive for rabbits and cattle. A preference was shown for ciconiiform birds during the spring (March-May). During the rest of the year, passeriiform birds served more as a source of bloodmeals for Cx. salinarius populations. Forage ratios indicated the use of passeriiform birds was not a function of preference, but rather a result of these birds being abundant at the up-county site. Results of this study substantiate earlier findings that Cx. salinarius females will use both mammals and birds as sources of bloodmeals. Females of this species are generalistic feeders and will utilize hosts that are in greatest abundance or which require the least amount of energy on the part of the mosquito to acquire.
Grieco, John Paul
Viscous Dissipation of Turbulence Kinetic Energy in Storms
In this note the magnitude of the viscous dissipation of turbulence kinetic energy in the surface layer of storms is investigated. It is shown that the layer-integrated dissipative heating is a cubic function of the wind speed. The magnitude of ...
Steven Businger; Joost A. Businger
Kinetic analysis of anaerobic fermentation of dry beef cattle manure
Influent total solids levels of 10, 20, 30 and 40% were tested for biogas production at 35/sup 0/C and C/N ratios of 11 and 25. Organic loading rates ranging from 5.0 to 10.6 kg VS m/sup -3/ d/sup -1/ were used and the Contois kinetic model was used to evaluate the data.
Schult, D.D.; Luis, V.
Seasonal Kinetic Energy Variability of Near-Inertial Motions
Seasonal variability of near-inertial horizontal kinetic energy is examined using observations from a series of McLane Moored Profiler moorings located at 39�N, 69�W in the western North Atlantic Ocean in combination with a one-dimensional, depth-...
Katherine E. Silverthorne; John M. Toole
Kinetic Isotope Effects from Hybrid Classical and Quantum
-order perturbation (KP2) is sufficiently accurate for chemical applications.7 We describe an automated, numerical in chemical applications to determine KIEs for chemical reactions, and because of its fast convergenceCHAPTER 5 Kinetic Isotope Effects from Hybrid Classical and Quantum Path Integral Computations
Minnesota, University of
Stepping and crowding: statistical kinetics from an exclusion process perspective
Motor enzymes are remarkable molecular machines that use the energy derived from the hydrolysis of a nucleoside triphosphate to generate mechanical movement, achieved through different steps that constitute their kinetic cycle. These macromolecules, nowadays investigated with advanced experimental techniques to unveil their molecular mechanisms and the properties of their kinetic cycles, are implicated in many biological processes, ranging from biopolymerisation (RNA polymerases, ribosomes,...) to intracellular transport (motor proteins such as kinesins or dyneins). Although the kinetics of individual motors is well studied on both theoretical and experimental grounds, the repercussions of their stepping cycle on the collective dynamics is still to be understood. Advances in this direction will improve our comprehension of transport process in the natural intracellular medium, where processive motor enzymes might operate in crowded conditions. In this work, we therefore extend the current statistical kinetic analysis to study collective transport phenomena of motors in terms of lattice gas models belonging to the exclusion process class. Via numerical simulations, we show how to interpret and use the randomness calculated from single particle trajectories in crowded conditions. Importantly, we also show that time fluctuations and non-Poissonian behavior are intrinsically related to spatial correlations and the emergence of large, but finite, clusters of co-moving motors. The properties unveiled by our analysis have important biological implications on the collective transport characteristics of processive motor enzymes in crowded conditions.
Luca Ciandrini; M. Carmen Romano; A. Parmeggiani
Kinetics of Oxygen Reduction in LSM and LSCF
1.00E-05 1.00E-04 1.00E-03 1.00E-02 1.00E-01 1.00E+00 -30 -25 -20 -15 -10 -5 0 5 LogpO2atm VA''' VB''' VO** MnB* MnBx MnB' Kinetic Measurements Using Polycrystalline...
Detailed chemical kinetic oxidation mechanism for a biodiesel surrogate
A detailed chemical kinetic mechanism has been developed and used to study the oxidation of methyl decanoate, a surrogate for biodiesel fuels. This model has been built by following the rules established by Curran et al. for the oxidation of n-heptane and it includes