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Advancing Reactive Tracer Methods for Measuring Thermal Evolution...
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History Facebook icon Twitter icon Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2- and Water-Based Geothermal Reservoirs Geothermal Lab Call Project...
Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2-
Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2- Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2- and Water-Based Geothermal Reservoirs Geothermal Lab Call Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2- and Water-Based Geothermal Reservoirs Project Type / Topic 1 Laboratory Call for Submission of Applications for Research, Development and Analysis of Geothermal Technologies Project Type / Topic 2 Tracers and Tracer Interpretation Project Description The concepts and theory behind the use of heat-sensitive tracers to study the thermal evolution of geothermal reservoirs was developed in the late 1980's under the Hot Dry Rock Project. Those studies described-conceptually and mathematically-the application of reactive tracers to tracking thermal fronts and to reservoir sizing. Later mathematical treatments focused on application of a single reactive tracer test to recover the temperature profile of a single streamtube. Previous tracer work has mainly focused on identifying conservative tracers. In these studies, chemicals that degraded at reservoir temperatures were discarded. Benzoic acids and dicarboxylic acids, which were found by Adams to degrade, may be useful as reactive tracers. Organic esters and amide tracers that undergo hydrolysis have been investigated and their use as reactive tracers appears feasible over a temperature range of 100ºC to 275ºC. However their reaction rates are pH dependent and sorption reactions have not been evaluated. While reactive tracer parameters have been measured in the lab, reactive tracers have not been extensively tested in the field. Thus, while reactive tracers appear to be a promising means of monitoring the thermal evolution of a geothermal reservoir, the concept has yet to be tested at the scale necessary for successful implementation, and tools for analyzing results of such tracer tests under the non-ideal conditions of an actual geothermal system have yet to be developed.
Science Conference Proceedings (OSTI)
Reactive tracers have long been considered a possible means of measuring thermal drawdown in a geothermal system, before significant cooling occurs at the extraction well. Here, we examine the sensitivity of the proposed method to evaluate reservoir cooling and demonstrate that while the sensitivity of the method as generally proposed is low, it may be practical under certain conditions.
Mitchell A. Plummer; Carl D. Palmer; Earl D. Mattson; George D. Redden; Laurence C. Hull
Advancing Reactive Tracer Methods for Measurement of Thermal Evolution in Geothermal Reservoirs: Final Report
DOE Green Energy (OSTI)
The injection of cold fluids into engineered geothermal system (EGS) and conventional geothermal reservoirs may be done to help extract heat from the subsurface or to maintain pressures within the reservoir (e.g., Rose et al., 2001). As these injected fluids move along fractures, they acquire heat from the rock matrix and remove it from the reservoir as they are extracted to the surface. A consequence of such injection is the migration of a cold-fluid front through the reservoir (Figure 1) that could eventually reach the production well and result in the lowering of the temperature of the produced fluids (thermal breakthrough). Efficient operation of an EGS as well as conventional geothermal systems involving cold-fluid injection requires accurate and timely information about thermal depletion of the reservoir in response to operation. In particular, accurate predictions of the time to thermal breakthrough and subsequent rate of thermal drawdown are necessary for reservoir management, design of fracture stimulation and well drilling programs, and forecasting of economic return. A potential method for estimating migration of a cold front between an injection well and a production well is through application of reactive tracer tests, using chemical whose rate of degradation is dependent on the reservoir temperature between the two wells (e.g., Robinson 1985). With repeated tests, the rate of migration of the thermal front can be determined, and the time to thermal breakthrough calculated. While the basic theory behind the concept of thermal tracers has been understood for some time, effective application of the method has yet to be demonstrated. This report describes results of a study that used several methods to investigate application of reactive tracers to monitoring the thermal evolution of a geothermal reservoir. These methods included (1) mathematical investigation of the sensitivity of known and hypothetical reactive tracers, (2) laboratory testing of novel tracers that would improve method sensitivity, (3) development of a software tool for design and interpretation of reactive tracer tests and (4) field testing of the reactive tracer temperature monitoring concept.
Mitchell A. Plummer; Carl D. Palmer; Earl D. Mattson; Laurence C. Hull; George D. Redden
Biological tracer method
DOE Patents (OSTI)
The present invention is a biological tracer method for characterizing the movement of a material through a medium, comprising the steps of: introducing a biological tracer comprising a microorganism having ice nucleating activity into a medium; collecting at least one sample of the medium from a point removed from the introduction point; and analyzing the sample for the presence of the biological tracer. The present invention is also a method for using a biological tracer as a label for material identification by introducing a biological tracer having ice nucleating activity into a material, collecting a sample of a portion of the labelled material and analyzing the sample for the presence of the biological tracer. 2 figs.
Strong-Gunderson, J.M.; Palumbo, A.V.
The present invention is a biological tracer method for characterizing the movement of a material through a medium, comprising the steps of: introducing a biological tracer comprising a microorganism having ice nucleating activity into a medium; collecting at least one sample of the medium from a point removed from the introduction point; and analyzing the sample for the presence of the biological tracer. The present invention is also a method for using a biological tracer as a label for material identification by introducing a biological tracer having ice nucleating activity into a material, collecting a sample of a portion of the labelled material and analyzing the sample for the presence of the biological tracer.
Strong-Gunderson, Janet M. (Ten Mile, TN); Palumbo, Anthony V. (Oak Ridge, TN)
Gas tracer composition and method
SciTech Connect
The invention provides a method for tagging methane by adding thereto one or more of the tracer compounds sulfur hexafluoride and chloropentafluoroethane. The methane being tagged is normally being stored in underground storage fields to provide identity and proof of ownership of the gas. The two tracer compounds are readily detectable at very low concentrations by electron capture gas chromatography apparatus which can be made portable and thus suitable for use in the field.
Malcosky, N. D.; Koziar, G.
Tracking thermal fronts with temperature-sensitive, chemically reactive tracers
Los Alamos is developing tracer techniques using reactive chemicals to track thermal fronts in fractured geothermal reservoirs. If a nonadsorbing tracer flowing from the injection to production well chemically reacts, its reaction rate will be a strong function of temperature. Thus the extent of chemical reaction will be greatest early in the lifetime of the system, and less as the thermal front progresses from the injection to production well. Early laboratory experiments identified tracers with chemical kinetics suitable for reservoirs in the temperature range of 75 to 100/sup 0/C. Recent kinetics studies have focused on the kinetics of hydrolysis of derivatives of bromobenzene. This class of reactions can be used in reservoirs ranging in temperature from 150 to 275/sup 0/C, which is of greater interest to the geothermal industry. Future studies will include laboratory adsorption experiments to identify possibly unwanted adsorption on granite, development of sensitive analytical techniques, and a field demonstration of the reactive tracer concept.
Robinson, B.A.; Birdsell, S.A.
Tracers and Tracer Testing: Design, Implementation, Tracer Selection, and Interpretation Methods
Conducting a successful tracer test requires adhering to a set of steps. The steps include identifying appropriate and achievable test goals, identifying tracers with the appropriate properties, and implementing the test as designed. When these steps are taken correctly, a host of tracer test analysis methods are available to the practitioner. This report discusses the individual steps required for a successful tracer test and presents methods for analysis. The report is an overview of tracer technology; the Suggested Reading section offers references to the specifics of test design and interpretation.
G. Michael Shook; Shannon L.; Allan Wylie
Experiments to Evaluate and Implement Passive Tracer Gas Methods...
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Experiments to Evaluate and Implement Passive Tracer Gas Methods to Measure Ventilation Rates in Homes Title Experiments to Evaluate and Implement Passive Tracer Gas Methods to...
A Method of Evaluating Atmospheric Models Using Tracer Measurements
The authors have developed a method that uses tracer measurements as the basis for comparing and evaluating wind fields. An important advantage of the method is that the wind fields are evaluated from the tracer measurements without introducing ...
Darko Kora?in; James Frye; Vlad Isakov
Passive Tracer Gas Methods to Measure
Experiments to Evaluate and Implement Experiments to Evaluate and Implement Passive Tracer Gas Methods to Measure Ventilation Rates in Homes Melissa Lunden, David Faulkner, Elizabeth Heredia, Sebastian Cohn, Darryl Dickerhoff, Federico Noris, Jennifer Logue, Toshifumi Hotchi, Brett Singer and Max H. Sherman Environmental Energy Technologies Division October 2012 LBNL-5984E 2 Disclaimer: This document was prepared as an account of work sponsored by the United States
Diagnostic Implications of the Reactivity of Fluorescence Tracers
Measurements of fuel concentration distributions with planar laser induced fluorescence of tracer molecules that are added to a base fuel are commonly used in combustion research and development. It usually is assumed that the tracer concentration follows the parent fuel concentration if physical properties such as those determining evaporation are matched. As an example to address this general issue a computational study of combustion of biacetyl/iso-octane mixtures was performed to investigate how well the concentration of biacetyl represents the concentration of iso-octane. For premixed mixture conditions with flame propagation the spatial concentration profiles of the two species in the flame front are separated by 110 {micro}m at 1 bar and by 11 {micro}m at 10 bar. For practical applications this spatial separation is insignificantly small. However, for conditions that mimic ignition and combustion in diesel and HCCI-like operation the differences in tracer and fuel concentration can be significant, exceeding hundreds of percent. At low initial temperature biacetyl was found to be more stable whereas at higher temperature (>1000K) iso-octane is more stable. Similar findings were obtained for a multi-component fuel comprised of iso-octane, n-heptane, methylcyclohexane, and toluene. It may be assumed that similar differences can exist for other tracer/fuel combinations. Caution has therefore to be applied when interpreting PLIF measurements in homogeneous reaction conditions such as in HCCI engine studies.
Sick, V; Westbrook, C
Preferred methods of analysis for chemical tracers in moderate...
Preferred methods of analysis for chemical tracers in moderate- and high-temperature geothermal environments Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report:...
Tracer Test Interpretation Methods for Reservior Properties
The purpose of this project is to develop tools that can be used to interpret tracer tests and obtain estimates of reservoir and operational parameters. These tools (mostly in the form of spreadsheet applications) can be used to optimize geothermal resource management.
Shook, George Michael
Preferred methods of analysis for chemical tracers in moderate- and
Preferred methods of analysis for chemical tracers in moderate- and Preferred methods of analysis for chemical tracers in moderate- and high-temperature geothermal environments Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Preferred methods of analysis for chemical tracers in moderate- and high-temperature geothermal environments Details Activities (2) Areas (2) Regions (0) Abstract: This report describes the sampling and analytical techniques used for tracer analysis in the Raft River and East Mesa field tests. The collection procedures and sample preservation techniques, analytical methods and possible sources of contamination or error are discussed in detail. Author(s): Kroneman, R. L.; Yorgason, K. R.; Moore, J. N. Published: DOE Information Bridge, 12/1/1984 Document Number: Unavailable DOI: 10.2172/5121460
Recent studies demonstrate the impact of fugitive emissions of reactive alkenes on the atmospheric chemistry of the Houston Texas metropolitan area (1). Petrochemical plants located in and around the Houston area emit atmospheric alkenes, such as ethene, propene and 1,3-butadiene. The magnitude of emissions is a major uncertainty in assessing their effects. Even though the petrochemical industry reports that fugitive emissions of alkenes have been reduced to less than 0.1% of daily production, recent measurement data, obtained during the TexAQS 2000 experiment indicates that emissions are perhaps a factor of ten larger than estimated values. Industry figures for fugitive emissions are based on adding up estimated emission factors for every component in the plant to give a total estimated emission from the entire facility. The dramatic difference between estimated and measured rates indicates either that calculating emission fluxes by summing estimates for individual components is seriously flawed, possibly due to individual components leaking well beyond their estimated tolerances, that not all sources of emissions for a facility are being considered in emissions estimates, or that there are known sources of emissions that are not being reported. This experiment was designed to confirm estimates of reactive alkene emissions derived from analysis of the TexAQS 2000 data by releasing perfluorocarbon tracers (PFTs) at a known flux from a petrochemical plant and sampling both the perfluorocarbon tracer and reactive alkenes downwind using the Piper-Aztec research aircraft operated by Baylor University. PFTs have been extensively used to determine leaks in pipelines, air infiltration in buildings, and to characterize the transport and dispersion of air parcels in the atmosphere. Over 20 years of development by the Tracer Technology Center (TTC) has produced a range of analysis instruments, field samplers and PFT release equipment that have been successfully deployed in a large variety of experiments. PFTs are inert, nontoxic, noncombustible and nonreactive. Up to seven unique PFTs can be simultaneously released, sampled and analyzed and the technology is well suited for determining emission fluxes from large petrochemical facilities. The PFT experiment described here was designed to quantitate alkene emissions from a single petrochemical facility, but such experiments could be applied to other industrial sources or groups of sources in the Houston area.
Single well tracer method to evaluate enhanced recovery
Data useful to evaluate the effectiveness of or to design an enhanced recovery process (the recovery process involving mobilizing and moving hydrocarbons through a hydrocarbon-bearing subterranean formation from an injection well to a production well by injecting a mobilizing fluid into the injection well) are obtained by a process which comprises sequentially: determining hydrocarbon saturation in the formation in a volume in the formation near a well bore penetrating the formation, injecting sufficient of the mobilizing fluid to mobilize and move hydrocarbons from a volume in the formation near the well bore penetrating the formation, and determining by the single well tracer method a hydrocarbon saturation profile in a volume from which hydrocarbons are moved. The single well tracer method employed is disclosed by U.S. Pat. No. 3,623,842. The process is useful to evaluate surfactant floods, water floods, polymer floods, CO.sub.2 floods, caustic floods, micellar floods, and the like in the reservoir in much less time at greatly reduced costs, compared to conventional multi-well pilot test.
Sheely, Jr., Clyde Q. (Ponca City, OK); Baldwin, Jr., David E. (Ponca City, OK)
A Tracer-Contour Inverse Method for Estimating Ocean Circulation and Mixing
A method is developed for estimating the along-isopycnal and vertical mixing coefficients (K and D) and the absolute velocity from time-averaged hydrographic data. The method focuses directly on transports down tracer gradients on isopycnals. ...
Jan D. Zika; Trevor J. McDougall; Bernadette M. Sloyan
The Urban Dispersion Program March 2005 Field Study tracer releases, sampling, and analytical methods are described in detail. There were two days where tracer releases and sampling were conducted. A total of 16.0 g of six tracers were released during the first test day or Intensive Observation Period (IOP) 1 and 15.7 g during IOP 2. Three types of sampling instruments were used in this study. Sequential air samplers, or SAS, collected six-minute samples, while Brookhaven atmospheric tracer samplers (BATS) and personal air samplers (PAS) collected thirty-minute samples. There were a total of 1300 samples resulting from the two IOPs. Confidence limits in the sampling and analysis method were 20% as determined from 100 duplicate samples. The sample recovery rate was 84%. The integrally averaged 6-minute samples were compared to the 30-minute samples. The agreement was found to be good in most cases. The validity of using a background tracer to calculate sample volumes was examined and also found to have a confidence level of 20%. Methods for improving sampling and analysis are discussed. The data described in this report are available as Excel files. An additional Excel file of quality assured tracer data for use in model validation efforts is also available. The file consists of extensively quality assured BATS tracer data with background concentrations subtracted.
Using chemically reactive tracers to determine temperature characteristics of geothermal reservoirs
The rates of most chemical reactions are very sensitive to temperature, and this property can be used to measure temperature patterns in geothermal reservoirs. Two approaches are considered: reverse-flush and flow-through. Both of these can indicate thermal drawdown faster than the measurement of produced-fluid temperature. The reverse-flush approach is more difficult to carry out and interferes more with normal operation, but it gives the earlier indication of thermal drawdown and yields more information when using a single reaction. In both approaches, injecting a suite of reactants can yield bivariate time-temperature distributions which give temperature distributions as functions of fluid residence time. Applications to Hot Dry Rock systems are considered throughout the paper. Results of early kinetics studies of candidate tracer reactions also are reported.
Robinson, B.A.; Tester, J.W.; Brown, L.F.
Single well surfactant test to evaluate surfactant floods using multi tracer method
Data useful for evaluating the effectiveness of or designing an enhanced recovery process said process involving mobilizing and moving hydrocarbons through a hydrocarbon bearing subterranean formation from an injection well to a production well by injecting a mobilizing fluid into the injection well, comprising (a) determining hydrocarbon saturation in a volume in the formation near a well bore penetrating formation, (b) injecting sufficient mobilizing fluid to mobilize and move hydrocarbons from a volume in the formation near the well bore, and (c) determining the hydrocarbon saturation in a volume including at least a part of the volume of (b) by an improved single well surfactant method comprising injecting 2 or more slugs of water containing the primary tracer separated by water slugs containing no primary tracer. Alternatively, the plurality of ester tracers can be injected in a single slug said tracers penetrating varying distances into the formation wherein the esters have different partition coefficients and essentially equal reaction times. The single well tracer method employed is disclosed in U.S. Pat. No. 3,623,842. This method designated the single well surfactant test (SWST) is useful for evaluating the effect of surfactant floods, polymer floods, carbon dioxide floods, micellar floods, caustic floods and the like in subterranean formations in much less time and at much reduced cost compared to conventional multiwell pilot tests.
Sheely, Clyde Q. (Ponca City, OK)
Single-well tracer methods for hydrogeologic evaluation of target aquifers
Designing an efficient well field for an aquifer thermal energy storage (ATES) project requires measuring local groundwater flow parameters as well as estimating horizontal and vertical inhomogeneity. Effective porosity determines the volume of aquifer needed to store a given volume of heated or chilled water. Ground-water flow velocity governs the migration of the thermal plume, and dispersion and heat exchange along the flow path reduces the thermal intensity of the recovered plume. Stratigraphic variations in the aquifer will affect plume dispersion, may bias the apparent rate of migration of the plume, and can prevent efficient hydraulic communication between wells. Single-well tracer methods using a conservative flow tracer such as bromide, along with pumping tests and water-level measurements, provide a rapid and cost-effective means for estimating flow parameters. A drift-and-pumpback tracer test yields effective porosity and flow velocity. Point-dilution tracer testing, using new instrumentation for downhole tracer measurement and a new method for calibrating the point-dilution test itself, yields depth-discrete hydraulic conductivity as it is affected by stratigraphy, and can be used to estimate well transmissivity. Experience in conducting both drift-and-pumpback and point-dilution tests at three different test sites has yielded important information that highlights both the power and the limitations of the single-well tracer methods. These sites are the University of Alabama Student Recreation Center (UASRC) ATES well field and the VA Medical Center (VA) ATES well field, both located in Tuscaloosa, Alabama, and the Hanford bioremediation test site north of Richland, Washington.
Hall, S.H.
Preferred methods of analysis for chemical tracers in moderate- and high-temperature geothermal environments
This report describes the sampling and analytical techniques used for tracer analysis in the Raft River and East Mesa field tests. The collection procedures and sample preservation techniques, analytical methods and possible sources of contamination or error are discussed in detail. 6 refs.
Kroneman, R.L.; Yorgason, K.R.; Moore, J.N.
SF6-3He Tracer Release Experiment: A New Method of
E-Print Network (OSTI)
. Gas Transfer Velocities. In addition to the longitudinal dispersion coefficient, gas transferSF6-3He Tracer Release Experiment: A New Method of Determining Longitudinal Dispersion Coefficients, Columbia University, Palisades, New York 10964 Longitudinal dispersion coefficients have been determined
Clark, Jordan
Perfluorocarbon tracer method for air-infiltration measurements
A method of measuring air infiltration rates suitable for use in rooms of homes and buildings comprises the steps of emitting perfluorocarbons in the room to be measured, sampling the air containing the emitted perfluorocarbons over a period of time, and analyzing the samples at a laboratory or other facility.
Dietz, R.N.
Method for generating a highly reactive plasma for exhaust gas after treatment and enhanced catalyst reactivity
This patent application describes a method and apparatus of exhaust gas remediation that enhance the reactivity of the material catalysts found within catalytic converters of cars, trucks, and power stations.
Whealton, John H.; Hanson, Gregory R.; Storey, John M.; Raridon, Richard J.; Armfield, Jeffrey S.; Bigelow, Timothy S.; Graves, Ronald L.
Method and apparatus for measuring reactivity of fissile material
Given are a method and apparatus for measuring nondestructively and noninvasively (i.e., using no internal probing) the burnup, reactivity, or fissile content of any material which emits neutrons and which has fissionable components. The assay is accomplished by altering the return flux of neutrons into the fuel assembly by means of changing the reflecting material. The existing passive neutron emissions in the material being assayed are used as the source of interrogating neutrons. Two measurements of either emitted neutron or emitted gamma-ray count rates are made and are then correlated to either reactivity, burnup, or fissionable content of the material being assayed, thus providing a measurement of either reactivity, burnup, or fissionable content of the material being assayed. Spent fuel which has been freshly discharged from a reactor can be assayed using this method and apparatus. Precisions of 1000 MWd/tU appear to be feasible.
Lee, D.M.; Lindquist, L.O.
Given are a method and apparatus for measuring nondestructively and non-invasively (i.e., using no internal probing) the burnup, reactivity, or fissile content of any material which emits neutrons and which has fissionable components. No external neutron-emitting interrogation source or fissile material is used and no scanning is required, although if a profile is desired scanning can be used. As in active assays, here both reactivity and content of fissionable material can be measured. The assay is accomplished by altering the return flux of neutrons into the fuel assembly. The return flux is altered by changing the reflecting material. The existing passive neutron emissions in the material being assayed are used as the source of interrogating neutrons. Two measurements of either emitted neutron or emitted gamma-ray count rates are made and are then correlated to either reactivity, burnup, or fissionable content of the material being assayed, thus providing a measurement of either reactivity, burnup, or fissionable content of the material being assayed. Spent fuel which has been freshly discharged from a reactor can be assayed using this method and apparatus. Precisions of 1000 MWd/tU appear to be feasible.
Lee, David M. (Los Alamos, NM); Lindquist, Lloyd O. (Santa Fe, NM)
Method for generating a highly reactive plasma for exhaust gas aftertreatment and enhanced catalyst reactivity
A method for non-thermal plasma aftertreatment of exhaust gases the method comprising the steps of providing short risetime, high frequency, high power bursts of low-duty factor microwaves sufficient to generate a plasma discharge and passing a gas to be treated through the discharge so as to cause dissociative reduction of the exhaust gases and enhanced catalyst reactivity through application of the pulsed microwave fields directly to the catalyst material sufficient to cause a polarizability catastrophe and enhanced heating of the metal crystallite particles of the catalyst, and in the presence or absence of the plasma. The invention also includes a reactor for aftertreatment of exhaust gases.
Whealton, John H. (Oak Ridge, TN); Hanson, Gregory R. (Clinton, TN); Storey, John M. (Oak Ridge, TN); Raridon, Richard J. (Oak Ridge, TN); Armfield, Jeffrey S. (Ypsilanti, MI); Bigelow, Timothy S. (Knoxville, TN); Graves, Ronald L. (Knoxville, TN)
Advanced hydraulic fracturing methods to create in situ reactive barriers
This article describes the use of hydraulic fracturing to increase permeability in geologic formations where in-situ remedial action of contaminant plumes will be performed. Several in-situ treatment strategies are discussed including the use of hydraulic fracturing to create in situ redox zones for treatment of organics and inorganics. Hydraulic fracturing methods offer a mechanism for the in-situ treatment of gently dipping layers of reactive compounds. Specialized methods using real-time monitoring and a high-energy jet during fracturing allow the form of the fracture to be influenced, such as creation of assymmetric fractures beneath potential sources (i.e. tanks, pits, buildings) that should not be penetrated by boring. Some examples of field applications of this technique such as creating fractures filled with zero-valent iron to reductively dechlorinate halogenated hydrocarbons, and the use of granular activated carbon to adsorb compounds are discussed.
Murdoch, L. [FRX Inc., Cincinnati, OH (United States)]|[Clemson Univ., SC (United States). Dept. of Geological Sciences; Siegrist, B.; Meiggs, T. [Oak Ridge National Lab., TN (United States)] [and others
Inert and Reacting Tracers for Reservoir Sizing in Fractured, Hot Dry Rock Systems
Flow characterization and volumetric sizing techniques using tracers in fractured hot dry rock reservoirs are discussed. Statistical methods for analyzing the residence time distribution (RTD) are presented. Tracer modal volumes and RTD shape are correlated with reservoir performance parameters such as active heat transfer area and dispersion levels. Chemically reactive tracers are proposed for mapping advance rates of cooled regions in HDR reservoirs, providing early warning of thermal drawdown. Important reaction rate parameters are identified for screening potential tracers. Current laboratory research and field work is reviewed.
Tester, J.W.; Robinson, B.A.; Ferguson, J.H.
Definition: Tracer Testing | Open Energy Information
Jump to: navigation, search Dictionary.png Tracer Testing A method based on injecting chemical tracers into the reservoir and monitoring how long it takes and where those tracers...
Tracer Testing | Open Energy Information
Tracer Testing Tracer Testing Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Tracer Testing Details Activities (9) Areas (5) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Testing Techniques Parent Exploration Technique: Well Testing Techniques Information Provided by Technique Lithology: Stratigraphic/Structural: Fracture zones and formation permeability Hydrological: Flow rates, flow direction, hydrologic connections, storativity Thermal: Dictionary.png Tracer Testing: A method based on injecting chemical tracers into the reservoir and monitoring how long it takes and where those tracers travel. The purpose is to model subsurface hydrothermal flow characteristics.
Tracers and Tracer Interpretation | Open Energy Information
Tracers and Tracer Interpretation Tracers and Tracer Interpretation Jump to: navigation, search Contents 1 Geothermal Lab Call Projects for Tracers and Tracer Interpretation 2 Geothermal ARRA Funded Projects for Tracers and Tracer Interpretation Geothermal Lab Call Projects for Tracers and Tracer Interpretation Loading map... {"format":"googlemaps3","type":"ROADMAP","types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"limit":200,"offset":0,"link":"all","sort":[""],"order":[],"headers":"show","mainlabel":"","intro":"","outro":"","searchlabel":"\u2026
A method for non-thermal plasma aftertreatment of exhaust gases the method comprising the steps of providing short risetime (about 40 ps), high frequency (about 5G hz), high power bursts of low-duty factor microwaves sufficient to generate a dielectric barrier discharge and passing a gas to treated through the discharge so as to cause dissociative reduction of the exhaust gases. The invention also includes a reactor for generating the non-thermal plasma.
Whealton, John H. (Oak Ridge, TN); Hanson, Gregory R. (Clinton, TN); Storey, John M. (Oak Ridge, TN); Raridon, Richard J. (Oak Ridge, TN); Armfield, Jeffrey S. (Upsilanti, MI); Bigelow, Timothy S. (Knoxville, TN); Graves, Ronald L. (Knoxville, TN)
Tracer Conservation with an Explicit Free Surface Method for z-Coordinate Ocean Models
This paper details a free surface method using an explicit time stepping scheme for use in z-coordinate ocean models. One key property that makes the method especially suitable for climate simulations is its very stable numerical time stepping ...
Stephen M. Griffies; Ronald C. Pacanowski; Martin Schmidt; V. Balaji
Combining Formal Methods for the Development of Reactive Systems
This article deals with the use of two verification approaches: theorem proving and model checking. We focus on the Event-B method by using its associated theorem proving tool (Click_n_Prove), and on the language TLA+ by using its model checker ... Keywords: Event-B method, Language TLA+, model-checking, predicate diagrams, theorem-proving
Olfa Mosbahi
Can Paleoceanographic Tracers Constrain Meridional Circulation Rates?
The ability of paleoceanographic tracers to constrain rates of transport is examined using an inverse method to combine idealized observations with a geostrophic model. Considered are the spatial distribution, accuracy, and types of tracers ...
Peter Huybers; Geoffrey Gebbie; Olivier Marchal
Combining formal methods for the development of reactive systems
This paper deals with the use of two verification approaches: theorem proving and model checking. We focus on the Event-B method by using its associated theorem proving tool (Click_n_Prove), and on the language TLA
Olfa Mosbahi; Mohamed Khalgui
BNL | Tracer Technology Group | BNL
Tracer Technology Group Tracer Technology Group Tracer Technology Image The Tracer Technology Group (TTG) developed the use of perfluorocarbon tracers (PFTs) as tools for studying long range atmospheric transport and dispersion in the early 1980s.We are world leaders in the use of PFTs for solving diverse research and engineering problems in the atmospheric sciences, the energy production and utility industries, and building characterization. The unique capabilities of the TTG are derived from our analytical expertise, infrastructure, and experience. We have developed PFT analytical methods that have detection limits at the femtogram level. We can measure global background levels of PFTS at the parts per quadrillion levels. Our scientists and technical staff have extensive experience in
Probing Material Reactivity Using X-ray Pair Distribution Function Methods
Material Reactivity Using X-ray Pair Distribution Material Reactivity Using X-ray Pair Distribution Function Methods Karena W. Chapman X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA Understanding how advanced functional materials react and transform, at an atomic scale, is a characterization challenge with many diverse phenomena possible; components with varying particle size, morphology, and microstructure can evolve from multi-atom clusters to multi-million atom crystals. The pair distribution function (PDF) method shows great promise for providing quantitative insight such reactions. Recent advances in experimental methods, have improved the efficiency of X-ray PDF measurements, to allow time-resolved experiments with sufficient resolution to study reactions in solid
Method of extruding and packaging a thin sample of reactive material including forming the extrusion die
This invention teaches a method of cutting a narrow slot in an extrusion die with an electrical discharge machine by first drilling spaced holes at the ends of where the slot will be, whereby the oil can flow through the holes and slot to flush the material eroded away as the slot is being cut. The invention further teaches a method of extruding a very thin ribbon of solid highly reactive material such as lithium or sodium through the die in an inert atmosphere of nitrogen, argon or the like as in a glovebox. The invention further teaches a method of stamping out sample discs from the ribbon and of packaging each disc by sandwiching it between two aluminum sheets and cold welding the sheets together along an annular seam beyond the outer periphery of the disc. This provides a sample of high purity reactive material that can have a long shelf life.
Lewandowski, Edward F. (Westmont, IL); Peterson, Leroy L. (Joliet, IL)
Method of extruding and packaging a thin sample of reactive material, including forming the extrusion die
This invention teaches a method of cutting a narrow slot in an extrusion die with an electrical discharge machine by first drilling spaced holes at the ends of where the slot will be, whereby the oil can flow through the holes and slot to flush the material eroded away as the slot is being cut. The invention further teaches a method of extruding a very thin ribbon of solid highly reactive material such as lithium or sodium through the die in an inert atmosphere of nitrogen, argon, or the like as in a glovebox. The invention further teaches a method of stamping out sample discs from the ribbon and of packaging each disc by sandwiching it between two aluminum sheets and cold welding the sheets together along an annular seam beyond the outer periphery of the disc. This provides a sample of high purity reactive material that can have a long shelf life.
Lewandowski, E.F.; Peterson, L.L.
Tracer airflow measurement system (TRAMS)
A method and apparatus for measuring fluid flow in a duct is disclosed. The invention uses a novel high velocity tracer injector system, an optional insertable folding mixing fan for homogenizing the tracer within the duct bulk fluid flow, and a perforated hose sampling system. A preferred embodiment uses CO.sub.2 as a tracer gas for measuring air flow in commercial and/or residential ducts. In extant commercial buildings, ducts not readily accessible by hanging ceilings may be drilled with readily plugged small diameter holes to allow for injection, optional mixing where desired using a novel insertable foldable mixing fan, and sampling hose.
Wang, Duo (Albany, CA)
Three-Dimensional Bayesian Geostatistical Aquifer Characterization at the Hanford 300 Area using Tracer Test Data
Tracer testing under natural or forced gradient flow holds the potential to provide useful information for characterizing subsurface properties, through monitoring, modeling and interpretation of the tracer plume migration in an aquifer. Non-reactive tracer experiments were conducted at the Hanford 300 Area, along with constant-rate injection tests and electromagnetic borehole flowmeter (EBF) profiling. A Bayesian data assimilation technique, the method of anchored distributions (MAD) [Rubin et al., 2010], was applied to assimilate the experimental tracer test data with the other types of data and to infer the three-dimensional heterogeneous structure of the hydraulic conductivity in the saturated zone of the Hanford formation. In this study, the Bayesian prior information on the underlying random hydraulic conductivity field was obtained from previous field characterization efforts using the constant-rate injection tests and the EBF data. The posterior distribution of the conductivity field was obtained by further conditioning the field on the temporal moments of tracer breakthrough curves at various observation wells. MAD was implemented with the massively-parallel three-dimensional flow and transport code PFLOTRAN to cope with the highly transient flow boundary conditions at the site and to meet the computational demands of MAD. A synthetic study proved that the proposed method could effectively invert tracer test data to capture the essential spatial heterogeneity of the three-dimensional hydraulic conductivity field. Application of MAD to actual field data shows that the hydrogeological model, when conditioned on the tracer test data, can reproduce the tracer transport behavior better than the field characterized without the tracer test data. This study successfully demonstrates that MAD can sequentially assimilate multi-scale multi-type field data through a consistent Bayesian framework.
Chen, Xingyuan; Murakami, Haruko; Hahn, Melanie S.; Hammond, Glenn E.; Rockhold, Mark L.; Zachara, John M.; Rubin, Yoram
Apparatus and method for atmospheric pressure reactive atom plasma processing for shaping of damage free surfaces
Fabrication apparatus and methods are disclosed for shaping and finishing difficult materials with no subsurface damage. The apparatus and methods use an atmospheric pressure mixed gas plasma discharge as a sub-aperture polisher of, for example, fused silica and single crystal silicon, silicon carbide and other materials. In one example, workpiece material is removed at the atomic level through reaction with fluorine atoms. In this example, these reactive species are produced by a noble gas plasma from trace constituent fluorocarbons or other fluorine containing gases added to the host argon matrix. The products of the reaction are gas phase compounds that flow from the surface of the workpiece, exposing fresh material to the etchant without condensation and redeposition on the newly created surface. The discharge provides a stable and predictable distribution of reactive species permitting the generation of a predetermined surface by translating the plasma across the workpiece along a calculated path.
Carr; Jeffrey W. (Livermore, CA)
Catalytic and reactive polypeptides and methods for their preparation and use
Catalytic and reactive polypeptides include a binding site specific for a reactant or reactive intermediate involved in a chemical reaction of interest. The polypeptides further include at least one active functionality proximate the binding site, where the active functionality is capable of catalyzing or chemically participating in the chemical reaction in such a way that the reaction rate is enhanced. Methods for preparing the catalytic peptides include chemical synthesis, site-directed mutagenesis of antibody and enzyme genes, covalent attachment of the functionalities through particular amino acid side chains, and the like. This invention was made with Government support under Grant Contract No. AI-24695, awarded by the Department of health and Human Services, and under Grant Contract No. N 00014-87-K-0256, awarded by the Office of Naval Research. The Government has certain rights in this invention.
Schultz, Peter (Oakland, CA)
Systems and methods for reactive distillation with recirculation of light components
Systems and methods for producing gas-to-liquids products using reactive distillation are provided. The method for producing gas-to-liquids products can include reacting a feedstock in a column having a distillation zone and a reaction zone to provide a bottoms stream and an overhead stream. A first portion of the overhead stream can be recycled to the column at the top of the reaction zone and second portion of the overhead stream can be recycled to the column at the bottom of the reaction zone.
Stickney, Michael J. (Nassau Bay, TX); Jones, Jr., Edward M. (Friendswood, TX)
GUINEVERE experiment: Kinetic analysis of some reactivity measurement methods by deterministic and Monte Carlo codes
The GUINEVERE experiment (Generation of Uninterrupted Intense Neutrons at the lead Venus Reactor) is an experimental program in support of the ADS technology presently carried out at SCK-CEN in Mol (Belgium). In the experiment a modified lay-out of the original thermal VENUS critical facility is coupled to an accelerator, built by the French body CNRS in Grenoble, working in both continuous and pulsed mode and delivering 14 MeV neutrons by bombardment of deuterons on a tritium-target. The modified lay-out of the facility consists of a fast subcritical core made of 30% U-235 enriched metallic Uranium in a lead matrix. Several off-line and on-line reactivity measurement techniques will be investigated during the experimental campaign. This report is focused on the simulation by deterministic (ERANOS French code) and Monte Carlo (MCNPX US code) calculations of three reactivity measurement techniques, Slope ({alpha}-fitting), Area-ratio and Source-jerk, applied to a GUINEVERE subcritical configuration (namely SC1). The inferred reactivity, in dollar units, by the Area-ratio method shows an overall agreement between the two deterministic and Monte Carlo computational approaches, whereas the MCNPX Source-jerk results are affected by large uncertainties and allow only partial conclusions about the comparison. Finally, no particular spatial dependence of the results is observed in the case of the GUINEVERE SC1 subcritical configuration. (authors)
Bianchini, G.; Burgio, N.; Carta, M. [ENEA C.R. CASACCIA, via Anguillarese, 301, 00123 S. Maria di Galeria Roma (Italy); Peluso, V. [ENEA C.R. BOLOGNA, Via Martiri di Monte Sole, 4, 40129 Bologna (Italy); Fabrizio, V.; Ricci, L. [Univ. of Rome La Sapienza, C/o ENEA C.R. CASACCIA, via Anguillarese, 301, 00123 S. Maria di Galeria Roma (Italy)
Catalytic and reactive polypeptides include a binding site specific for a reactant or reactive intermediate involved in a chemical reaction of interest. The polypeptides further include at least one active functionality proximate the bi.
Method for cracking hydrocarbon compositions using a submerged reactive plasma system
A method for cracking a liquid hydrocarbon composition (e.g. crude oil) to produce a cracked hydrocarbon product. A liquid hydrocarbon composition is initially provided. An electrical arc is generated directly within the hydrocarbon composition so that the arc is entirely submerged in the composition. Arc generation is preferably accomplished using a primary and secondary electrode each having a first end submerged in the composition. The first ends of the electrodes are separated from each other to form a gap therebetween. An electrical potential is then applied to the electrodes to generate the arc within the gap. A reactive gas is thereafter delivered to the arc which forms a bubble around the arc. Gas delivery may be accomplished by providing a passageway through each electrode and delivering the gas through the passageways. The arc and gas cooperate to produce a plasma which efficiently cracks the hydrocarbon composition.
Kong, Peter C. (Idaho Falls, ID)
A method is described for cracking a liquid hydrocarbon composition (e.g. crude oil) to produce a cracked hydrocarbon product. A liquid hydrocarbon composition is initially provided. An electrical arc is generated directly within the hydrocarbon composition so that the arc is entirely submerged in the composition. Arc generation is preferably accomplished using a primary and secondary electrode each having a first end submerged in the composition. The first ends of the electrodes are separated from each other to form a gap there between. An electrical potential is then applied to the electrodes to generate the arc within the gap. A reactive gas is thereafter delivered to the arc which forms a bubble around the arc. Gas delivery may be accomplished by providing a passageway through each electrode and delivering the gas through the passageways. The arc and gas cooperate to produce a plasma which efficiently cracks the hydrocarbon composition. 6 figs.
Kong, P.C.
Microseismic Tracer Particles for Hydraulic Fracturing
Microseismic Tracer Particles for Hydraulic Fracturing Microseismic Tracer Particles for Hydraulic Fracturing Microseismic Tracer Particles for Hydraulic Fracturing Scientists at Los Alamos National Laboratory have developed a method by which microseismic events can be discriminated/detected that correspond to only the portion of the hydraulic fracture that contains the proppant material and can be expected to be conductive to the flow of oil and gas. July 3, 2013 Microseismic Tracer Particles for Hydraulic Fracturing Figure 1: A graph of ionic conductivity as a function of temperature for the anti-perovskite Li3OCl. Available for thumbnail of Feynman Center (505) 665-9090 Email Microseismic Tracer Particles for Hydraulic Fracturing Applications: Oil and gas production Geophysical exploration Benefits: Tracks the disposition of material in a hydraulic fracturing
Using Thermally Degrading, Partitioning and Nonreactive Tracers...
Type Topic 2 Tracers and Tracer Interpretation Project Description The goal of this project is to provide integrated tracer and tracer interpretation tools to facilitate this...
Long-Term Tracer Study at Los Alamos, New Mexico. Part II: Evaluation and Comparison of Several Methods to Determine Dispersion Coefficients
A long-term tracer study was conducted to evaluate dispersion in complex terrain in support of air quality and emergency response initiatives. An array of monitors continuously measured external radiation levels at different directions and ...
Brent M. Bowen
Tracer Testing At Raft River Geothermal Area (1984) | Open Energy...
L.; Yorgason, K. R.; Moore, J. N. (1 December 1984) Preferred methods of analysis for chemical tracers in moderate- and high-temperature geothermal environments Retrieved from...
Tracer Testing At East Mesa Geothermal Area (1984) | Open Energy...
Comparative study for EAF's reactive energy compensation methods and power factor improvement
In this paper is analyzing the current operating conditions of one electric arc furnace (EAF) in order to evaluate the best option to solve the energy consumption problem. Experimental results show that EAFs represent a substantial source of electric ... Keywords: electric arc furnace, flicker, harmonic analysis, improvement, power factor, reactive compensator
Deaconu Sorin Ioan; Popa Gabriel Nicolae; Tihomir Latinovic
Sensitivity analysis of reactivity responses using one-dimensional discrete ordinates and three-dimensional Monte Carlo methods
The TSUNAMI computational sequences currently in the SCALE 5 code system provide an automated approach to performing sensitivity and uncertainty analysis for eigenvalue responses, using either one-dimensional discrete ordinates or three-dimensional Monte Carlo methods. This capability has recently been expanded to address eigenvalue-difference responses such as reactivity changes. This paper describes the methodology and presents results obtained for an example advanced CANDU reactor design. (authors)
Williams, M. L.; Gehin, J. C.; Clarno, K. T. [Oak Ridge National Laboratory, Bldg. 5700, P.O. Box 2008, Oak Ridge, TN 37831-6170 (United States)
Gas tracer composition and method. [Process to determine whether any porous underground methane storage site is in fluid communication with a gas producing well
A process is described for determining whether any porous underground gaseous methane storage sites is in fluid communication with a gas producing well, and if there is fluid communication, determining which site is in the fluid communication comprising injecting a different gaseous tracer mixture into each of the sites at some location in each of the site in an amount such that the presence of the tracer mixture will be detectable in the gaseous methane stored therein, each of the mixture having the properties of (1) not occurring in natural supplies of methane, (2) diffusing through any underground methane storage site in a manner very similar in rate to methane, and (3) being substantially insoluble in petroleum distillates, after a period of time sufficient for each of the tracer mixtures to diffuse through the underground site from its injection location to the well, withdrawing a sample gaseous product from the well, testing the sample gaseous product for the presence of each of the tracer mixtures.
Malcosky, N.D.; Koziar, G.
Effective Eddy Diffusivities Inferred from a Point Release Tracer in an Eddy-Resolving Ocean Model
This study uses tracer experiments in a global eddy-resolving ocean model to examine two diagnostic methods for inferring effective eddy isopycnic diffusivity from point release tracers. The first method is based on the growth rate of the area ...
Mei-Man Lee; A. J. George Nurser; Andrew C. Coward; Beverly A. de Cuevas
An Integrated Approach to Characterizing Bypassed Oil in Heterogeneous and Fractured Reservoirs Using Partitioning Tracers
We explore the use of efficient streamline-based simulation approaches for modeling partitioning interwell tracer tests in hydrocarbon reservoirs. Specifically, we utilize the unique features of streamline models to develop an efficient approach for interpretation and history matching of field tracer response. A critical aspect here is the underdetermined and highly ill-posed nature of the associated inverse problems. We have investigated the relative merits of the traditional history matching ('amplitude inversion') and a novel travel time inversion in terms of robustness of the method and convergence behavior of the solution. We show that the traditional amplitude inversion is orders of magnitude more non-linear and the solution here is likely to get trapped in local minimum, leading to inadequate history match. The proposed travel time inversion is shown to be extremely efficient and robust for practical field applications. The streamline approach is generalized to model water injection in naturally fractured reservoirs through the use of a dual media approach. The fractures and matrix are treated as separate continua that are connected through a transfer function, as in conventional finite difference simulators for modeling fractured systems. A detailed comparison with a commercial finite difference simulator shows very good agreement. Furthermore, an examination of the scaling behavior of the computation time indicates that the streamline approach is likely to result in significant savings for large-scale field applications. We also propose a novel approach to history matching finite-difference models that combines the advantage of the streamline models with the versatility of finite-difference simulation. In our approach, we utilize the streamline-derived sensitivities to facilitate history matching during finite-difference simulation. The use of finite-difference model allows us to account for detailed process physics and compressibility effects. The approach is very fast and avoids much of the subjective judgments and time-consuming trial-and-errors associated with manual history matching. We demonstrate the power and utility of our approach using a synthetic example and two field examples. We have also explored the use of a finite difference reservoir simulator, UTCHEM, for field-scale design and optimization of partitioning interwell tracer tests. The finite-difference model allows us to include detailed physics associated with reactive tracer transport, particularly those related with transverse and cross-streamline mechanisms. We have investigated the potential use of downhole tracer samplers and also the use of natural tracers for the design of partitioning tracer tests. Finally, we discuss several alternative ways of using partitioning interwell tracer tests (PITTs) in oil fields for the calculation of oil saturation, swept pore volume and sweep efficiency, and assess the accuracy of such tests under a variety of reservoir conditions.
Akhil Datta-Gupta
Obtaining Velocities from Tracer Distributions
A simple advective-diffusive system with uniform, horizontal flow in a channel and fixed boundary concentrations of two tracers is analyzed for the tracer concentrations in the interior. The deduced concentrations are then treated as given ...
Manuel E. Fiadeiro; George Veronis
Tracer Verification of Trajectory Models
Perfluorocarbon tracer data collected during the Cross Appalachian Tracer Experiment (CAPTEX '83) are used to determine the accuracy of three trajectory models: an isentropic, an isobaric, and a dimensional sigma model. The root-mean-square ...
Philip L. Haagenson; Ying-Hwa Kuo; Marina Syumanich; Nelson L. Seaman
Tracer Testing At Coso Geothermal Area (1993) | Open Energy Information
Tracer Testing At Coso Geothermal Area (1993) Tracer Testing At Coso Geothermal Area (1993) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Tracer Testing At Coso Geothermal Area (1993) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Tracer Testing Activity Date 1993 Usefulness useful DOE-funding Unknown Exploration Basis To determine the steam and water mass flow rate Notes The method involves precisely metered injection of liquid and vapor phase tracers into the two-phase production pipeline and concurrent sampling of each phase downstream of the injection point. Subsequent chemical analysis of the steam and water samples for tracer content enables the calculation of mass flowrate for each phase given the known mass injection rates of
System for reactivating catalysts
A method of reactivating a catalyst, such as a solid catalyst or a liquid catalyst is provided. The method comprises providing a catalyst that is at least partially deactivated by fouling agents. The catalyst is contacted with a fluid reactivating agent that is at or above a critical point of the fluid reactivating agent and is of sufficient density to dissolve impurities. The fluid reactivating agent reacts with at least one fouling agent, releasing the at least one fouling agent from the catalyst. The at least one fouling agent becomes dissolved in the fluid reactivating agent and is subsequently separated or removed from the fluid reactivating agent so that the fluid reactivating agent may be reused. A system for reactivating a catalyst is also disclosed.
Ginosar, Daniel M. (Idaho Falls, ID); Thompson, David N. (Idaho Falls, ID); Anderson, Raymond P. (Idaho Falls, ID)
Methods for modeling impact-induced reactivity changes in small reactors.
This paper describes techniques for determining impact deformation and the subsequent reactivity change for a space reactor impacting the ground following a potential launch accident or for large fuel bundles in a shipping container following an accident. This technique could be used to determine the margin of subcriticality for such potential accidents. Specifically, the approach couples a finite element continuum mechanics model (Pronto3D or Presto) with a neutronics code (MCNP). DAGMC, developed at the University of Wisconsin-Madison, is used to enable MCNP geometric queries to be performed using Pronto3D output. This paper summarizes what has been done historically for reactor launch analysis, describes the impact criticality analysis methodology, and presents preliminary results using representative reactor designs.
Tallman, Tyler N.; Radel, Tracy E.; Smith, Jeffrey A.; Villa, Daniel L.; Smith, Brandon M. (U. of Wisconsin, Madison, WI); Radel, Ross F.; Lipinski, Ronald J.; Wilson, Paul Philip Hood (U. of Wisconsin, Madison, WI)
Measurements of waste tank passive ventilation rates using tracer gases
This report presents the results of ventilation rate studies of eight passively ventilated high-level radioactive waste tanks using tracer gases. Head space ventilation rates were determined for Tanks A-101, AX-102, AX-103, BY-105, C-107, S-102, U-103, and U-105 using sulfur hexafluoride (SF{sub 6}) and/or helium (He) as tracer gases. Passive ventilation rates are needed for the resolution of several key safety issues. These safety issues are associated with the rates of flammable gas production and ventilation, the rates at which organic salt-nitrate salt mixtures dry out, and the estimation of organic solvent waste surface areas. This tracer gas study involves injecting a tracer gas into the tank headspace and measuring its concentration at different times to establish the rate at which the tracer is removed by ventilation. Tracer gas injection and sample collection were performed by SGN Eurisys Service Corporation and/or Lockheed Martin Hanford Corporation, Characterization Project Operations. Headspace samples were analyzed for He and SF{sub 6} by Pacific Northwest National Laboratory (PNNL). The tracer gas method was first demonstrated on Tank S-102. Tests were conducted on Tank S-102 to verify that the tracer gas was uniformly distributed throughout the tank headspace before baseline samples were collected, and that mixing was sufficiently vigorous to maintain an approximately uniform distribution of tracer gas in the headspace during the course of the study. Headspace samples, collected from a location about 4 in away from the injection point and 15, 30, and 60 minutes after the injection of He and SF{sub 6}, indicated that both tracer gases were rapidly mixed. The samples were found to have the same concentration of tracer gases after 1 hour as after 24 hours, suggesting that mixing of the tracer gas was essentially complete within 1 hour.
Huckaby, J.L.; Olsen, K.B.; Sklarew, D.S.; Evans, J.C.; Remund, K.M.
Enhanced Oil Recovery: Aqueous Flow Tracer Measurement
A low detection limit analytical method was developed to measure a suite of benzoic acid and fluorinated benzoic acid compounds intended for use as tracers for enhanced oil recovery operations. Although the new high performance liquid chromatography separation successfully measured the tracers in an aqueous matrix at low part per billion levels, the low detection limits could not be achieved in oil field water due to interference problems with the hydrocarbon-saturated water using the system's UV detector. Commercial instrument vendors were contacted in an effort to determine if mass spectrometry could be used as an alternate detection technique. The results of their work demonstrate that low part per billion analysis of the tracer compounds in oil field water could be achieved using ultra performance liquid chromatography mass spectrometry.
Joseph Rovani; John Schabron
Microsoft PowerPoint - Tracer plume detection-LANL(Fessenden).ppt
Tracer Testing of Plume Movement Tracer Testing of Plume Movement Julianna Fessenden and Paul Reimus, Los Alamos National Laboratory Plume modeling (atmosphere, reservoir, groundwater) Purpose of Tracing Plumes Monitor species of interest within reservoir Monitor species of interest outside reservoir Monitor Flow paths Capture zones Monitor Breaches Extent of movement Desirable Tracer Characteristics (1) Inexpensive (measurement, analytical) (2) Low detection limits, no analytical interferences (3) Quick, easy to sample and measure (4) Non toxic, readily permitted (5) Both sorbing/non-sorbing tracer use Perflorocarbon Tracer deployment NETL facilities Classes of Tracers (1) Gas Phase (2) Liquid Phase (3) Organic, inorganic, aqueous (4) Conservative/nonreacting (5) Reactive with mineral surfaces or soluble in non-carrier phase
Experimental evaluation of an instrumented synthesis method for the real-time estimation of reactivity. Master's thesis
This research is part of an investigation into the feasibility of using reactor-generated signals in an instrumented synthesis method for the real-time estimation, of reactivity. The method utilizes in-core neutron detectors to evaluate local core power distributions for eventual use in an on-line controller. Although numerical evaluation of the synthesis method has proven successful, this experimental work was conducted to determine if the signals provided by actual in-core sensors in an operating reactor could be used with this technique. For this study, an instrumentation system was designed and built to obtain neutron flux data from three fission chamber neutron detectors. This instrumentation system was installed in the 5 Mw(thermal) research reactor at the Massachusetts Institute of Technology (MITR-II). The flux data resulting from the experiments was used to determine the optimal locations for additional detectors to be used in future experiments and to show the limitations and difficulties of this method. Recommendations are presented for correcting these short-comings in the research and for future areas of study.
Selby, L.C.
Experimental evaluation of an instrumented synthesis method for the real-time estimation of reactivity
This report concerns the first and second quarters supported under this grant. The period covered is 1 July 1992--31 December 1992. Progress is reported for tasks involving: Theoretical characterization of flux shapes; experimental determination of flux shapes; experimental evaluation of instrumented synthesis method; and controller design.
Not Available
Development of Models to Simulate Tracer Tests for Characterization of Enhanced Geothermal Systems
A recent report found that power and heat produced from enhanced (or engineered) geothermal systems (EGSs) could have a major impact on the U.S energy production capability while having a minimal impact on the environment. EGS resources differ from high-grade hydrothermal resources in that they lack sufficient temperature distribution, permeability/porosity, fluid saturation, or recharge of reservoir fluids. Therefore, quantitative characterization of temperature distributions and the surface area available for heat transfer in EGS is necessary for the design and commercial development of the geothermal energy of a potential EGS site. The goal of this project is to provide integrated tracer and tracer interpretation tools to facilitate this characterization. This project was initially focused on tracer development with the application of perfluorinated tracer (PFT) compounds, non-reactive tracers used in numerous applications from atmospheric transport to underground leak detection, to geothermal systems, and evaluation of encapsulated PFTs that would release tracers at targeted reservoir temperatures. After the 2011 midyear review and subsequent discussions with the U.S. Department of Energy Geothermal Technology Program (GTP), emphasis was shifted to interpretive tool development, testing, and validation. Subsurface modeling capabilities are an important component of this project for both the design of suitable tracers and the interpretation of data from in situ tracer tests, be they single- or multi-well tests. The purpose of this report is to describe the results of the tracer and model development for simulating and conducting tracer tests for characterizing EGS parameters.
Williams, Mark D.; Reimus, Paul; Vermeul, Vincent R.; Rose, Peter; Dean, Cynthia A.; Watson, Tom B.; Newell, D.; Leecaster, Kevin; Brauser, Eric
Tracer Diffusion Databases for ICME
... of a large repository of stable isotopes that can be utilized for tracer diffusion .... Lattice Dynamics and Thermodynamics of Lithium Battery Materials LiMPO4�...
An experimental evaluation of the instrumented flux synthesis method for the real-time estimation of reactivity. Final report
One method of determining the flux density is flux synthesis which approximates the flux in the core by linear combinations of precomputed shape functions. In traditional flux synthesis, the unknown mixing coefficients are determined using a weighted residual method of solving the diffusion equation. In the instrumented synthesis method, the mixing coefficients are determined using count rates from neutron detectors in the core. In this way the mixing coefficients are linked to conditions in the reactor. Using the synthesized flux, kinetics parameters, notably reactivity, can be calculated in real time. An experimental evaluation has been performed in the Massachusetts Institute of Technology Reactor, MITR-II. Detector measurements have been collected using fission chambers placed at the periphery of the core. The reactor was put into a number of various conditions, both static and transient, and data were collected using a digital acquisition system for later combination with shape functions. Transients included increasing power, decreasing power, and a reactor scram. The shape functions were generated using Version 3.0 of the QUARTZ code, a quadratic nodal diffusion theory code in triangular-Z geometry. Supernodal analysis algorithms have been added to the original program, along with subroutines to guarantee diagonal dominance of the leakage matrix in the finite difference or quadratic current approximations in the coarse mesh. The agreement between coarse mesh and fine mesh in all cases is excellent, with finite difference coarse mesh solutions generally slightly better. The synthesis method has been shown to accurately reflect the changes from an initial condition by combining representative flux shapes. It can be concluded that, with proper calibration of the measurement system and inclusion of representative flux shapes, the instrumented synthesis method will properly predict the flux in the core under a number of conditions.
Hughes, J.C.; Henry, A.F.; Lanning, D.D.; Bernard, J.A.
We explore the use of efficient streamline-based simulation approaches for modeling partitioning interwell tracer tests in hydrocarbon reservoirs. Specifically, we utilize the unique features of streamline models to develop an efficient approach for interpretation and history matching of field tracer response. A critical aspect here is the underdetermined and highly ill-posed nature of the associated inverse problems. We have adopted an integrated approach whereby we combine data from multiple sources to minimize the uncertainty and non-uniqueness in the interpreted results. For partitioning interwell tracer tests, these are primarily the distribution of reservoir permeability and oil saturation distribution. A novel approach to multiscale data integration using Markov Random Fields (MRF) has been developed to integrate static data sources from the reservoir such as core, well log and 3-D seismic data. We have also explored the use of a finite difference reservoir simulator, UTCHEM, for field-scale design and optimization of partitioning interwell tracer tests. The finite-difference model allows us to include detailed physics associated with reactive tracer transport, particularly those related with transverse and cross-streamline mechanisms. We have investigated the potential use of downhole tracer samplers and also the use of natural tracers for the design of partitioning tracer tests. Finally, the behavior of partitioning tracer tests in fractured reservoirs is investigated using a dual-porosity finite-difference model.
Tracer dating and ocean ventilation
The interpretation of transient tracer observations depends on dif�cult to obtain information on the evolution in time of the tracer boundary conditions and interior distributions. Recent studies have attempted to circumvent this problem by making use of a derived quantity, age, based on the simultaneous distribution of two complementary tracers, such as tritium and its daughter, helium 3. The age is defined with reference to the surface such that the boundary condition takes on a constant value of zero. We use a two-dimensional model to explore the circumstances under which such a combination of conservation equations for two complementary tracers can lead to a cancellation of the time derivative terms. An interesting aspect of this approach is that mixing can serve as a source or sink of tracer based age. We define an idealized "ventilation age tracer " that is conservative with respect to mixing, and we explore how its behavior compares with that of the tracer-based ages over a range of advective and diffusive parameters. 1.
G. Thiele; J. L. Sarmiento
Innovative techniques for the description of reservoir heterogeneity using tracers. Final report, October 1992--December 1993
This is the final report of a three year research project on the use of tracers for reservoir characterization. The objective of this research was to develop advanced, innovative techniques for the description of reservoir characteristics using both single-well backflow and interwell tracer tests. (1) The authors implemented and validated tracer modeling features in a compositional simulator (UTCOMP). (2) They developed and applied a new single well tracer test for estimating reservoir heterogeneity. (3) They developed and applied a new single well tracer test for estimating reservoir wettability in-situ. (4) They developed a new, simple and efficient method to analyze two well tracer tests based upon type curve matching and illustrated its use with actual field tracer data. (5) They developed a new method for deriving an integrated reservoir description based upon combinatorial optimization schemes. (6) They developed a new, interwell tracer test for reservoir heterogeneity called vertical tracer profiling (VTP) and demonstrated its advantages over conventional interwell tracer testing. (7) They developed a simple and easy analytical method to estimate swept pore volume from interwell tracer data and showed both the theoretical basis for this method and its practical utility. (8) They made numerous enhancements to our compositional reservoir simulator such as including the full permeability tensor, adding faster solvers, improving its speed and robustness and making it easier to use (better I/0) for tracer simulation problems. (9) They applied the enhanced version of UTCOMP to the analysis of interwell tracer data using perfluorocarbons at Elks Hill Naval Petroleum Reserve. All of these accomplishments taken together have significantly improved the state of reservoir tracer technology and have demonstrated that it is a far more powerful and useful tool for quantitative reservoir characterization than previously realized or practiced by the industry.
Pope, G.A.; Sepehrnoori, K.; Delshad, M.; Ferreira, L.; Gupta, A.; Maroongroge, V.
An adaptive sparse-grid high-order stochastic collocation method for Bayesian inference in groundwater reactive transport modeling
Although Bayesian analysis has become vital to the quantification of prediction uncertainty in groundwater modeling, its application has been hindered due to the computational cost associated with numerous model executions needed for exploring the posterior probability density function (PPDF) of model parameters. This is particularly the case when the PPDF is estimated using Markov Chain Monte Carlo (MCMC) sampling. In this study, we develop a new approach that improves computational efficiency of Bayesian inference by constructing a surrogate system based on an adaptive sparse-grid high-order stochastic collocation (aSG-hSC) method. Unlike previous works using first-order hierarchical basis, we utilize a compactly supported higher-order hierar- chical basis to construct the surrogate system, resulting in a significant reduction in the number of computational simulations required. In addition, we use hierarchical surplus as an error indi- cator to determine adaptive sparse grids. This allows local refinement in the uncertain domain and/or anisotropic detection with respect to the random model parameters, which further improves computational efficiency. Finally, we incorporate a global optimization technique and propose an iterative algorithm for building the surrogate system for the PPDF with multiple significant modes. Once the surrogate system is determined, the PPDF can be evaluated by sampling the surrogate system directly with very little computational cost. The developed method is evaluated first using a simple analytical density function with multiple modes and then using two synthetic groundwater reactive transport models. The groundwater models represent different levels of complexity; the first example involves coupled linear reactions and the second example simulates nonlinear ura- nium surface complexation. The results show that the aSG-hSC is an effective and efficient tool for Bayesian inference in groundwater modeling in comparison with conventional MCMC sim- ulations. The computational efficiency is expected to be more beneficial to more computational expensive groundwater problems.
Zhang, Guannan [ORNL; Webster, Clayton G [ORNL; Gunzburger, Max D [ORNL
Reactivity monitoring using the area method for the subcritic al VENUS-F core within the framework of the FREYA Project
Accelerator-Driven Systems (ADS) could be employed to incinerate minor actinides and so partly contribute to answer the problem of nuclear waste management. An ADS consists of the coupling of a subcritical fast reactor to a particle accelerator via a heavy material spallation target. The on-line reactivity monitoring of such an ADS is a serious issue regarding its safety. In order to study the methodology of this monitoring, zero-power experimentswere undertaken at the GUINEVERE facility within the framework of the FP6-IP-EUROTRANS programme. Such experiments have been under completion within the FREYA FP7 project. The GUINEVERE facility is hosted at the SCK-CEN site in Mol (Belgium). It couples the VENUS-F subcritical fast core with the GENEPI-3C accelerator. The latter delivers a beam of deuterons, which are converted into 14-MeV neutrons via fusion reactions on a tritiated target. This paper presents one of the investigated methods for ADS on-line reactivity monitoring which has to be validated in the program of the FREYA project. It describes the results obtained when Pulsed Neutron Source experiments are analysed using the so called Area Method, in order to estimate the reactivity of a few sub-critical configurations of the VENUS-F reactor, around keff= 0.96. First the GUINEVERE facility is described. Then, following general considerations on the Area method, the results of its application to the neutron population time decrease spectra measured after a pulse by several fission chambers spread out over the whole reactor are discussed. Finally the reactivity values extracted are compared to the static reactivity values obtained using the Modified Source Multiplication (MSM) method.
N. Marie; G. Lehaut; J. L. Lecouey; A. Billebaud; S. Chabod; X. Doligez; F. R. Lecolley; A. Kochetkov; W. Uyttenhove; G. Vittiglio; J. Wagemans; F. Mellier; G. Ban; H. E. Thy�bault; D. Villamarin
A Tracer Test Using Ethanol as a Two-Phase Tracer and 2-Naphthalene
Tracer Test Using Ethanol as a Two-Phase Tracer and 2-Naphthalene Tracer Test Using Ethanol as a Two-Phase Tracer and 2-Naphthalene Sulfonate as a Liquid-Phase Tracer at the Coso Geothermal Field Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: A Tracer Test Using Ethanol as a Two-Phase Tracer and 2-Naphthalene Sulfonate as a Liquid-Phase Tracer at the Coso Geothermal Field Details Activities (1) Areas (1) Regions (0) Abstract: A tracer test was conducted at the Coso geothermal field in order to characterize the flow patterns of fluid injected into well 68-20RD. A conservative liquid phase tracer, 2-naphthalene sulfonate, and a two-phase tracer, ethanol, were injected into well 68-20RD. Surrounding production wells were sampled over the subsequent 125 days and analyzed for the two tracers. The liquid-phase tracer showed negligible returns, whereas the
Quantitative interpretation of tracer test data | Open Energy Information
Quantitative interpretation of tracer test data Quantitative interpretation of tracer test data Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Quantitative interpretation of tracer test data Abstract Geothermal reinjection is an important part of sustainable management of geothermal resources. Reinjection started out as a method of waste-water disposal, but is now also being used to counteract pressure draw-down and to extract more thermal energy from reservoir rocks. The possible cooling of production wells, or thermal breakthrough, is one of the main disadvantages associated with injection. To minimize this danger while maintaining the benefit from reinjection requires careful testing and research. Tracer testing, which is used to study flow-paths and quantify fluid-flow in hydrological systems, is probably the most important tool for
A Tracer Test Using Ethanol as a Two-Phase Tracer and 2-Naphthalene...
Tracer Test Using Ethanol as a Two-Phase Tracer and 2-Naphthalene Sulfonate as a Liquid-Phase Tracer at the Coso Geothermal Field Jump to: navigation, search GEOTHERMAL...
Gas Bubbles as Oceanographic Tracers
Air bubbles can be used as oceanographic tracers that indicate the strength of a downwelling current by which they are subducted. In a tidal front in the Fraser Estuary, British Columbia, Canada, vertical currents of up to 0.70 m s?1 subduct ...
Burkard Baschek; David M. Farmer
A hypercube Ray-tracer
We describe a hypercube ray-tracing program for rendering computer graphics. For small models, which fit in the memory of a single processor, the ray-tracer uses a scattered decomposition of pixels to balance the load, and achieves a very high efficiency. ...
J. Salmon; J. Goldsmith
Tracer dispersion in the turbulent convective layer
Experimental results for passive tracer dispersion in the turbulent surface layer under convective conditions are presented. In this case, the dispersion of tracer particles is determined by the interplay of two mechanisms: buoyancy and advection. ...
Alex Skvortsov; Milan Jamriska; Timothy C. DuBois
Meteorological Tracer Techniques for Parameterizing Atmospheric Dispersion
Although tracer materials have been used in atmospheric dispersion studies for decades, basic information about meteorological tracer techniques is scattered among a number of different sources. This paper attempts to pull together this ...
Warren B. Johnson
Propagation of Tracer Signals in Boundary Currents
The propagation of a range of tracer signals in a simple model of the deep western boundary current is examined. Analytical expressions are derived in certain limits for the transit-time distributions and the propagation times (tracer ages) of ...
Darryn W. Waugh; Timothy M. Hall
Groundwater prospecting for sandstone-type uranium deposits: the merits of mineral-solution equilibria versus single element tracer methods. Volume II
This report presents the results of further research on the groundwater geochemistry of 96 well waters in two uraniferous aquifers in Texas and Wyoming, and is a continuation of the work presented by Chatham et al. (1981). In this study variations in concentrations of U, As, Mo, Se and V were compared with the saturation state of the groundwater with respect to mineral phases of these elements known or expected to occur in each area. The non-radiogenic trace elements exhibited strong redox dependence consistent with thermodynamic predictions, but their variations did not pinpoint existing uranium ore bodies, because of a shift in groundwater flow patterns since the time of ore emplacement. Saturation levels of trace element minerals such as realgar, native Se, and molybdenite showed broad anomalies around the ore-bearing areas, similar to patterns found for U minerals by Langmuir and Chatham (1980), and Chatham et al. (1981). The radiogenic elements Ra and Rn showed significant anomalies directly within the ore zones. Helium anomalies were displaced in the direction of groundwater flow, but by their magnitude and areal extent provided strong evidence for the existence of nearby uranium accumulations. Uranium isotope ratios showed no systematic variations within the two aquifers studied. Saturation maps for kaolinite, illite, montmorillonite and the zeolites analcime and clinoptilolite provided 1 to 2 km anomalies around the ore at the Texas site. Saturation values for the gangue minerals pyrite and calcite defined the redox interface and often suggested the position of probable uranium mineralization. When properly used, the groundwater geochemical concepts for exploration can accurately pinpoint uranium mineralization at a fraction of the cost of conventional methods that involve test drilling and geophysical and core logging.
Wanty, R.B.; Langmuir, D.; Chatham, J.R.
Brush potential curve tracer
A device for analyzing commutating characteristics of a motor or generator includes a holder for supporting a plurality of probes adjacent a brush of the motor or generator. Measurements of electrical current characteristics in each of the probes provides information useful in analyzing operation of the machine. Methods for employing a device in accordance with the invention are also disclosed.
Finch, Hilvan A. (Schenectady, NY)
A device for analyzing commutating characteristics of a motor or generator includes a holder for supporting a plurality of probes adjacent a brush of the motor or generator. Measurements of electrical current characteristics of the probes provides information useful in analyzing operation of the machine. Methods for employing a device in accordance with the invention are also disclosed.
Finch, H.A.
High-performance high-resolution semi-Lagrangian tracer transport on a sphere
Current climate models have a limited ability to increase spatial resolution because numerical stability requires the time step to decrease. We describe a semi-Lagrangian method for tracer transport that is stable for arbitrary Courant numbers, and we ... Keywords: Cubed sphere, High resolution, High-performance computing, Semi-Lagrangian, Spherical geometry, Tracer transport
J. B. White, III; J. J. Dongarra
Multiple-tracer gas analyzer
A multi-gas tracer system has been designed, built, and used on an explosively fractured oil shale rubble bed. This paper deals exclusively with the hardware, software, and overall operation of the tracer system. This system is a field portable, self-contained unit, which utilizes a mass spectrometer for gas analysis. The unit has a 20 channel sample port capability and is controlled by a desk top computer. The system is configured to provide a dynamic sensitivity range of up to six orders of magnitude. A roots blower is manifolded to the unit to provide continuous flow in all sample lines. The continuous flow process allows representative samples as well as decreasing the time between each measurement. Typical multiplex cycle time to evaluate four unique gases is approximately 12 seconds.
Uhl, J.E.
Novel Application of Single-Well Tracer Tests to Evaluate Hydraulic Stimulation Effectiveness
This paper presents a graphical method by which one can identify the number of fractures and their permeability distribution in the near-well region from single-well tracer tests. The method is an extension of tracer analysis methods developed previously to estimate flow geometry and relies on caluclating the relative fluid velocity from F-__ plots. A number of numerical examples show that high flow zones (fractures) are readily identified from the derivatives of an F-___ curve. The method can be used in evaluating well stimulation efforts by conducting a tracer test before and after the stimulation and comparing the velocity distributions.
G. M. Shook; Gopi Nalla
Three-dimensional visualization of reactive flows in complex geometries
The visualization of fluid flows has become more challenging, as recent advancements in computational methods have increased the complexity and size of simulations. Our objective is to develop a flexible flow visualization tool for fluid simulations that include the full physics and geometrical complexities found in modeling practical combustion systems, such as internal combustion engines. The challenges to flow visualization come from: (1) the large simulation output, especially when using massively parallel computers; (2) the increasingly complex geometries that include moving surfaces such as pistons and valves; (3) the complex physical phenomena in realistic problems of fuel injection, combustion fronts, boundary flows, and large scale turbulence; and (4) the numerical complexity of indirect addressing of computational elements, variable mesh connectivity, distorted elements, and moving meshes. We have developed a visualization program that addresses these complexities. The program was developed as a post-processor to the KIVA family of codes for reactive flow simulations. Because of the complexity of the KIVA codes, the visualization program is very versatile and applicable to any code with meshes of arbitrary hexahedrons. No comparable commercial visualization package could be found. To visualize the fluid flow, we use mass-less tracer particles that follow the movement of the fluid as determined from output files from the simulation. The movement of the tracer particles is based on a second-order spatial and temporal interpolation of the fluid velocities from successive simulation output files. The visualization program runs on a Silicon Graphics IRIS GTX workstation.
Fairfield, M.S.
Reactive power compensator
A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.
El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Woodinville, WA); Chen, Mingliang (Kirkland, WA); Andexler, George (Everett, WA); Huang, Tony (Seattle, WA)
Reactive Power Compensator.
A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation. 26 figs.
El-Sharkawi, M.A.; Venkata, S.S.; Chen, M.; Andexler, G.; Huang, T.
Accelerator-Driven Systems (ADS) could be employed to incinerate minor actinides and so partly contribute to answer the problem of nuclear waste management. An ADS consists of the coupling of a subcritical fast reactor to a particle accelerator via a heavy material spallation target. The on-line reactivity monitoring of such an ADS is a serious issue regarding its safety. In order to study the methodology of this monitoring, zero-power experimentswere undertaken at the GUINEVERE facility within the framework of the FP6-IP-EUROTRANS programme. Such experiments have been under completion within the FREYA FP7 project. The GUINEVERE facility is hosted at the SCK-CEN site in Mol (Belgium). It couples the VENUS-F subcritical fast core with the GENEPI-3C accelerator. The latter delivers a beam of deuterons, which are converted into 14-MeV neutrons via fusion reactions on a tritiated target. This paper presents one of the investigated methods for ADS on-line reactivity monitoring which has to be validated in the prog...
Marie, N; Lecouey, J L; Billebaud, A; Chabod, S; Doligez, X; Lecolley, F R; Kochetkov, A; Uyttenhove, W; Vittiglio, G; Wagemans, J; Mellier, F; Ban, G; Thy�bault, H E; Villamarin, D
Petroleum characterization by perfluorocarbon tracers
Perfluorocarbon tracers (PFTs), a class of six compounds, were used to help characterize the Shallow Oil Zone (SOZ) reservoir at the Naval Petroleum Reserve in California (NPRC) at Elk Hills. The SOZ reservoir is undergoing a pilot gas injection program to assess the technical feasibility and economic viability of injecting gas into the SOZ for improved oil recovery. PFTs were utilized in the pilot gas injection to qualitatively assess the extent of the pilot gas injection so as to determine the degree of gas containment within the SOZ reservoir.
Senum, G.I.; Fajer, R.W. (Brookhaven National Lab., Upton, NY (United States)); Harris, B.R. Jr. (USDOE Naval Petroleum Reserves in California, Tupman, CA (United States)); DeRose, W.E. (Bechtel Petroleum Operations, Inc., Tupman, CA (United States)); Ottaviani, W.L. (Chevron U.S.A., Inc., Bakersfield, CA (United States))
Doublet Tracer Testing in Klamath Falls, Oregon
A tracer test was carried out in a geothermal doublet system to study the injection behavior of a developed reservoir known to be fractured. The doublet produces about 320 gpm of 160 F water that is used for space heating and then injected; the wells are spaced 250 ft apart. Tracer breakthrough was observed in 2 hours and 45 minutes in the production well, indicating fracture flow. However, the tracer concentrations were low and indicated porous media flow; the tracers mixed with a reservoir volume much larger than a fracture.
Gudmundsson, J.S.; Johnson, S.E.; Horne, R.N.; Jackson, P.B.; Culver, G.G.
Truncation Effects on Estimated Parameters of Tracer Distributions Sampled on Finite Domains
Methods are presented and demonstrated for compensating for the apparent effect of truncation of the sampled crosswind distribution of a tracer, at either or both boundaries of a surface sampling grid downwind from the point of release. Errors ...
J. Z. Holland
Predictive value of tracer studies for /sup 131/I treatment in hyperthyroid cats
In 76 cats with hyperthyroidism, peak thyroidal radioiodine (/sup 131/I) uptakes and effective half-lives were determined after administration of tracer and therapeutic activities of /sup 131/I. In 6 additional hyperthyroid cats, only peak thyroidal uptakes after administration of tracer and therapeutic activities of /sup 131/I were determined. Good correlation was found between peak thyroidal uptakes of tracer and therapeutic /sup 131/I; however, only fair correlation was observed between effective half-lives. In 79% of the cats, the effective half-life for therapeutic /sup 131/I was longer than that for tracer /sup 131/I. After administration of therapeutic activity of /sup 131/I, monoexponential and biphasic decay curves were observed in 51 and 16 cats, respectively. Using therapeutic kinetic data, radiation doses to the thyroid gland were calculated retrospectively on the basis of 2 methods for determining the activity of /sup 131/I administered: (1) actual administration of tracer-compensated activity and (2) hypothetic administration of uniform activity (3 mCi). Because of the good predictive ability of tracer kinetic data for the therapeutic kinetic data, the tracer-compensated radiation doses came significantly (P = 0.008) closer to the therapeutic goal than did the uniform-activity doses. In addition, the use of tracer kinetic information reduced the extent of the tendency for consistently high uniform-activity doses. A manual method for acquiring tracer kinetic data was developed and was an acceptable alternative to computerized techniques. Adoption of this method gives individuals and institutions with limited finances the opportunity to characterize the iodine kinetics in cats before proceeding with administration of therapeutic activities of /sup 131/I.
Broome, M.R.; Turrel, J.M.; Hays, M.T.
Microsoft PowerPoint - Tracer plume detection-LANL(Fessenden...
Artificially introduced or naturally present All tracers will partition into liquid and gas phases -T,P, Depth Dependent Information Gathered from Tracers (1)Reservoir volume...
Experimental Determination of Tracer Dispersivity in Fractures
Reinjection of waste hot water is commonly practiced in most geothermal fields, primarily as a means of disposal. Surface discharge of these waste waters is usually unacceptable due to the resulting thermal and chemical pollution. Although reinjection can help to main reservoir pressure and fluid volume, in some cases a decrease in reservoir productivity has been observed. This is caused by rapid flow of the reinjected water through fractures connecting the injector and producers. As a result, the water is not sufficiently heated by the reservoir rock, and a reduction in enthalpy of the produced fluids is seen. Tracer tests have proven to be valuable to reservoir engineers for the design of a successful reinjection program. By injecting a slug of tracer and studying the discharge of surrounding producing wells, an understanding of the fracture network within a reservoir can be provided. In order to quantify the results of a tracer test, a model that accurately describes the mechanisms of tracer transport is necessary. One such mechanism, dispersion, is like a smearing out of a tracer concentration due to the velocity gradients over the cross section of flow. If a dispersion coefficient can be determined from tracer test data, the fracture width can be estimated. The purpose of this project was to design and construct an apparatus to study the dispersion of a chemical tracer in flow through a fracture.
Gilardi, J.; Horns, R.N.
Tracer Developments: Results of Experimental Studies
Tracers can be used to monitor the movement of groundwaters and geothermal fluids and they can be used as a reference to quantify changes in fluid chemistry as a result of injection. Despite their potential importance to the geothermal operator, very few tracers are presently available and of those that are, little is known about their stability or behavior at the elevated temperatures that typify resources capable of electric power generation. During the past two years the University of Utah Research Institute has been involved in tracer research and testing, largely through the DOE Injection Research Program. The purpose of this paper is to summarize the results of these laboratory and field investigations.
Adams, M.C.; Ahn, J.H.; Bentley, H.; Moore, J.N.; Veggeberg, S.
Effect of room air recirculation delay on the decay rate of tracer gas
Effect of room air recirculation delay on the decay rate of tracer gas Effect of room air recirculation delay on the decay rate of tracer gas concentration Title Effect of room air recirculation delay on the decay rate of tracer gas concentration Publication Type Journal Article Year of Publication 2007 Authors Lorenzetti, David M., Astrid H. Kristoffersen, and Ashok J. Gadgil Journal Indoor Air Pagination 7 Keywords recirculating ventilation, tracer decay rate Abstract Tracer gas measurements are used to estimate the flow rate of fresh air into a room or building. These methods commonly account for the decay of tracer gas concentration as the result of ventilation air supply and infiltration, using a well-mixed model of the space. Some researchers also have considered the effect of leakage in the ventilation ductwork. This paper considers the effect of recirculation through ventilation ducts on the calculated fresh air supply rate. Transport delay in the ducts can significantly alter the time evolution of tracer concentration, and hence alter the estimated air change rate.
Effect of room air recirculation delay on the decay rate of tracer gas Effect of room air recirculation delay on the decay rate of tracer gas Title Effect of room air recirculation delay on the decay rate of tracer gas Publication Type Conference Proceedings Year of Publication 2004 Authors Kristoffersen, Astrid H., Ashok J. Gadgil, and David M. Lorenzetti Conference Name 9th International Conference on Air Distribution in Rooms - RoomVent 2004, Pagination pp 6 Date Published September 5-8, 2 Conference Location Coimbra, Portugal Abstract Tracer gas measurements are commonly used to estimate the fresh air exchange rate in a room or building. Published tracer decay methods account for fresh air supply, infiltration, and leaks in ductwork. However, the time delay associated with a ventilation system recirculating tracer back to the room also affects the decay rate. We present an analytical study of tracer gas decay in a well-mixed, mechanically-ventilated room with recirculation. The analysis shows that failing to account for delays can lead to under- or over-estimates of the fresh air supply, depending on whether the decay rate calculation includes the duct volume
Reactive Air Aluminization
Ferritic stainless steels and other alloys are of great interest to SOFC developers for applications such as interconnects, cell frames, and balance of plant components. While these alloys offer significant advantages (e.g., low material and manufacturing cost, high thermal conductivity, and high temperature oxidation resistance), there are challenges which can hinder their utilization in SOFC systems; these challenges include Cr volatility and reactivity with glass seals. To overcome these challenges, protective coatings and surface treatments for the alloys are under development. In particular, aluminization of alloy surfaces offers the potential for mitigating both evaporation of Cr from the alloy surface and reaction of alloy constituents with glass seals. Commercial aluminization processes are available to SOFC developers, but they tend to be costly due to their use of exotic raw materials and/or processing conditions. As an alternative, PNNL has developed Reactive Air Aluminization (RAA), which offers a low-cost, simpler alternative to conventional aluminization methods.
Choi, Jung-Pyung; Chou, Y. S.; Stevenson, Jeffry W.
Determining Velocities and Mixing Coefficients from Tracers
The effort to determine oceanic velocities from tracer distributions relies on a knowledge of the effects of mixing. However, the macroscopic diffusion coefficient, K, is generally not known and must be calculated along with the velocity. The ...
Jae Hak Lee; George Veronis
Tracer Leakage from Modeled Agulhas Rings
In a numerical, isopycnal, ocean model the mixing is investigated with the environment of two idealized Agulhas rings, one that splits, and one that remains coherent. The evolution of a passive tracer, initially contained within the rings, shows ...
L. de Steur; P. J. van Leeuwen; S. S. Drijfhout
When Are Eddy Tracer Fluxes Directed Downgradient?
The mechanisms controlling the direction of eddy tracer fluxes are examined using eddy-resolving isopycnic experiments for a cyclic zonal channel. Eddy fluxes are directed downgradient on average when either (i) there is a Lagrangian increase in ...
Chris Wilson; Richard G. Williams
Tracers and Potential Vorticities in Ocean Dynamics
The Ertel potential vorticity theorem for stratified viscous fluids in a rotating system is analyzed herein. A set of �tracers,� that is, materially conserved scalar quantities, and the corresponding Ertel potential vorticities are used to obtain ...
Michael V. Kurgansky; Giorgio Budillon; Ettore Salusti
Photoacoustic infrared spectroscopy for conducting gas tracer tests and measuring water saturations in landfills
Highlights: Black-Right-Pointing-Pointer Photoacoustic infrared spectroscopy tested for measuring tracer gas in landfills. Black-Right-Pointing-Pointer Measurement errors for tracer gases were 1-3% in landfill gas. Black-Right-Pointing-Pointer Background signals from landfill gas result in elevated limits of detection. Black-Right-Pointing-Pointer Technique is much less expensive and easier to use than GC. - Abstract: Gas tracer tests can be used to determine gas flow patterns within landfills, quantify volatile contaminant residence time, and measure water within refuse. While gas chromatography (GC) has been traditionally used to analyze gas tracers in refuse, photoacoustic spectroscopy (PAS) might allow real-time measurements with reduced personnel costs and greater mobility and ease of use. Laboratory and field experiments were conducted to evaluate the efficacy of PAS for conducting gas tracer tests in landfills. Two tracer gases, difluoromethane (DFM) and sulfur hexafluoride (SF{sub 6}), were measured with a commercial PAS instrument. Relative measurement errors were invariant with tracer concentration but influenced by background gas: errors were 1-3% in landfill gas but 4-5% in air. Two partitioning gas tracer tests were conducted in an aerobic landfill, and limits of detection (LODs) were 3-4 times larger for DFM with PAS versus GC due to temporal changes in background signals. While higher LODs can be compensated by injecting larger tracer mass, changes in background signals increased the uncertainty in measured water saturations by up to 25% over comparable GC methods. PAS has distinct advantages over GC with respect to personnel costs and ease of use, although for field applications GC analyses of select samples are recommended to quantify instrument interferences.
Jung, Yoojin; Han, Byunghyun; Mostafid, M. Erfan; Chiu, Pei [Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716 (United States); Yazdani, Ramin [Yolo County Planning and Public Works Department, Division of Integrated Waste Management, Yolo County, 44090 County Rd. 28H, Woodland, CA 95776 (United States); Imhoff, Paul T., E-mail: email@example.com [Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716 (United States)
Using Biofuel Tracers to Study Alternative Combustion Regimes
Section B (NIMB) Using Biofuel Tracers to Study Alternativeinjection. We investigate biofuel HCCI combustion, and use
Mack, John Hunter; Flowers, Daniel L.; Buchholz, Bruce A.; Dibble, Robert W.
Analysis of tracer and thermal transients during reinjection
This work studied tracer and thermal transients during reinjection in geothermal reserviors and developed a new technique which combines the results from interwell tracer tests and thermal injection-backflow tests to estimate the thermal breakthrough times. Tracer tests are essential to determine the degree of connectivity between the injection wells and the producing wells. To analyze the tracer return profiles quantitatively, we employed three mathematical models namely, the convection-dispersion (CD) model, matrix diffusion (MD) model, and the Avodnin (AD) model, which were developed to study tracer and heat transport in a single vertical fracture. We considered three types of tracer tests namely, interwell tracer tests without recirculation, interwell tracer tests with recirculation, and injection-backflow tracer tests. To estimate the model parameters, we used a nonlinear regression program to match tracer return profiles to the solutions.
Kocabas, I.
Benchmarks for Quantifying Fuel Reactivity Depletion Uncertainty
Analytical methods, described in this report, are used to systematically determine experimental fuel sub-batch reactivities as a function of burnup. Fuel sub-batch reactivities are inferred using more than 600 in-core pressurized water reactor (PWR) flux maps taken during 44 cycles of operation at the Catawba and McGuire nuclear power plants. The analytical methods systematically search for fuel sub-batch reactivities that minimize differences between measured and computed reaction rates, using Studsvik ...
Graphical Analysis of PET Data Applied to Reversible and Irreversible Tracers
Graphical analysis refers to the transformation of multiple time measurements of plasma and tissue uptake data into a linear plot, the slope of which is related to the number of available tracer binding sites. This type of analysis allows easy comparisons among experiments. No particular model structure is assumed, however it is assumed that the tracer is given by bolus injection and that both tissue uptake and the plasma concentration of unchanged tracer are monitored following tracer injection. The requirement of plasma measurements can be eliminated in some cases when a reference region is available. There are two categories of graphical methods which apply to two general types of ligands--those which bind reversibly during the scanning procedure and those which are irreversible or trapped during the time of the scanning procedure.
Logan, Jean
Thermal Stability of Chelated Indium Activable Tracers
The thermal stability of indium tracer chelated with organic ligands ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) was measured for reservoir temperatures of 150, 200, and 240 C. Measurements of the soluble indium concentration was made as a function of time by neutron activation analysis. From the data, approximate thermal decomposition rates were estimated. At 150 C, both chelated tracers were stable over the experimental period of 20 days. At 200 C, the InEDTA concentration remained constant for 16 days, after which the thermal decomposition occurred at a measured rate constant of k = 0.09 d{sup -1}. The thermal decomposition of InNTA at 200 C showed a first order reaction with a measured rate constant of k = 0.16 d{sup -1}. At 240 C, both indium chelated tracers showed rapid decomposition with rate constants greater than 1.8 d{sup -1}. The data indicate that for geothermal reservoir with temperatures up to about 200 C, indium chelated tracers can be used effectively for transit times of at least 20 days. These experiments were run without reservoir rock media, and do not account for concomitant loss of indium tracer by adsorption processes.
Chrysikopoulos, Costas; Kruger, Paul
Geologic flow characterization using tracer techniques
A new tracer flow-test system has been developed for in situ characterization of geologic formations. This report describes two sets of test equipment: one portable and one for testing in deep formations. Equations are derived for in situ detector calibration, raw data reduction, and flow logging. Data analysis techniques are presented for computing porosity and permeability in unconfined isotropic media, and porosity, permeability and fracture characteristics in media with confined or unconfined two-dimensional flow. The effects of tracer pulse spreading due to divergence, dispersion, and porous formations are also included.
Klett, R. D.; Tyner, C. E.; Hertel, Jr., E. S.
A 3-D hydrodynamic dispersion model for modeling tracer transport in Geothermal Reservoirs
diffusion of a tracer or a radionuclide. This new module ofsimulate processes of tracer/radionuclide transport using ana) a tracer or a radionuclide is present and transported
Wu, Yu-Shu; Pruess, Karsten
Eulerian Simulation of Tracer Distribution during CAPTEX
We compared observed and model-simulated surface concentration on a spatial wale of 1100 km and a temporal scale of 36 h. The Eulerian tracer model calculated advection by the mean winds and gradient transport for subgrid-scale turbulent ...
Richard A. Brost; Philip L. Haagenson; Ying-Hwa Kuo
Tracer Testing At Coso Geothermal Area (2006) | Open Energy Information
Tracer Testing At Coso Geothermal Area (2006) Tracer Testing At Coso Geothermal Area (2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Tracer Testing At Coso Geothermal Area (2006) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Tracer Testing Activity Date 2006 Usefulness useful DOE-funding Unknown Exploration Basis To characterize the flow patterns of fluid injected into well 68-20RD. Notes A conservative liquid phase tracer, 2-naphthalene sulfonate, and a two-phase tracer, ethanol, were injected into well 68-20RD. Surrounding production wells were sampled over the subsequent 125 days and analyzed for the two tracers. The results demonstrate the efficacy of the simultaneous use of liquid-phase and two-phase tracers in fluid-depleted geothermal
Constraining North Atlantic circulation with transient tracer observations
The capability of transient tracers to constrain the ocean circulation in the North Atlantic is explored. Study of an idealized tracer shows that inferences of circulation properties from transient state distributions are ...
Li, Xingwen, 1968-
A Continuous Fast-Response Dual-Tracer Analyzer for Halogenated Atmospheric Tracer Studies
An apparatus for the simultaneous measurement of two tracers, sulfur hexafluoride (SF6) and a perfluorocarbon compound, is introduced. The new instrument is a modification of a commercially available fast-response, continuous analyzer for single ...
James P. Rydock; Brian K. Lamb
Proceedings: Fossil Plant Layup and Reactivation Conference
In recent years, the layup and reactivation of fossil-fired power plants has become more important as increasing numbers of utilities develop a need for retaining capacity not currently needed. A 1992 EPRI conference highlighted key technical issues, focusing on proven layup procedures, descriptions of layup equipment and preservation methods, layup and reactivation case studies, and summaries of regulatory issues.
A method is given for production-line determination of the specific neutronic reactivity of such objects as individual nuclear fuel or neutron absorber elements and is notable for rapidity and apparatus simplicity. The object is incorporated in a slightly sub-critical chain fission reactive assembly having a discrete neutron source, thereby establishing a K/sub eff/ within the crucial range of 0.95 to 0.995. The range was found to afford, uniquely, flux- transient damped response in a niatter of seconds simultaneously with acceptable analytical sensitivity. The resulting neutron flux measured at a situs spaced from both object and source within the assembly serves as a calibrable indication of said reactivity.
Dessauer, G.
Enthalpy and mass flowrate measurements for two-phase geothermal production by Tracer dilution techniques
A new technique has been developed for the measurement of steam mass flowrate, water mass flowrate and total enthalpy of two-phase fluids produced from geothermal wells. The method involves precisely metered injection of liquid and vapor phase tracers into the two-phase production pipeline and concurrent sampling of each phase downstream of the injection point. Subsequent chemical analysis of the steam and water samples for tracer content enables the calculation of mass flowrate for each phase given the known mass injection rates of tracer. This technique has now been used extensively at the Coso geothermal project, owned and operated by California Energy Company. Initial validation of the method was performed at the Roosevelt Hot Springs geothermal project on wells producing to individual production separators equipped with orificeplate flowmeters for each phase.
Hirtz, Paul; Lovekin, Jim; Copp, John; Buck, Cliff; Adams, Mike
Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain site characterization study. Final report
Extensive tracer testing is expected to take place at the C-well complex in the Nevada Test Site as part of the Yucca Mountain Site Characterization Project. The C-well complex consists of one pumping well, C3, and two injection wells, C1 and C2 into which tracer will be introduced. The goal of this research was to provide USGS with numerous tracers to completed these tests. Several classes of fluorinated organic acids have been evaluated. These include numerous isomers of fluorinated benzoic acids, cinnamic acids, and salicylic acids. Also several derivatives of 2-hydroxy nicotinic acid (pyridone) have been tested. The stability of these compounds was determined using batch and column tests. Ames testing (mutagenicity/carcinogenicity) was conducted on the fluorinated benzoic acids and a literature review of toxicity of the fluorobenzoates and three perfluoro aliphatic acids was prepared. Solubilities were measured and method development work was performed to optimize the detection of these compounds. A Quality Assurance (QA) Program was developed under existing DOE and USGS guidelines. The program includes QA procedures and technical standard operating procedures. A tracer test, using sodium iodide, was performed at the C-well complex. HRC chemists performed analyses on site, to provide real time data for the USGS hydrologists and in the laboratories at UNLV. Over 2,500 analyses were performed. This report provides the results of the laboratory experiments and literature reviews used to evaluate the potential tracers and reports on the results of the iodide C-well tracer test.
Stetzenbach, K.; Farnham, I.
Systematic approach for chemical reactivity evaluation
Under certain conditions, reactive chemicals may proceed into uncontrolled chemical reaction pathways with rapid and significant increases in temperature, pressure, and/or gas evolution. Reactive chemicals have been involved in many industrial incidents, and have harmed people, property, and the environment. Evaluation of reactive chemical hazards is critical to design and operate safer chemical plant processes. Much effort is needed for experimental techniques, mainly calorimetric analysis, to measure thermal reactivity of chemical systems. Studying all the various reaction pathways experimentally however is very expensive and time consuming. Therefore, it is essential to employ simplified screening tools and other methods to reduce the number of experiments and to identify the most energetic pathways. A systematic approach is presented for the evaluation of reactive chemical hazards. This approach is based on a combination of computational methods, correlations, and experimental thermal analysis techniques. The presented approach will help to focus the experimental work to the most hazardous reaction scenarios with a better understanding of the reactive system chemistry. Computational methods are used to predict reaction stoichiometries, thermodynamics, and kinetics, which then are used to exclude thermodynamically infeasible and non-hazardous reaction pathways. Computational methods included: (1) molecular group contribution methods, (2) computational quantum chemistry methods, and (3) correlations based on thermodynamic-energy relationships. The experimental techniques are used to evaluate the most energetic systems for more accurate thermodynamic and kinetics parameters, or to replace inadequate numerical methods. The Reactive System Screening Tool (RSST) and the Automatic Pressure Tracking Adiabatic Calorimeter (APTAC) were employed to evaluate the reactive systems experimentally. The RSST detected exothermic behavior and measured the overall liberated energy. The APTAC simulated near-adiabatic runaway scenarios for more accurate thermodynamic and kinetic parameters. The validity of this approach was investigated through the evaluation of potentially hazardous reactive systems, including decomposition of di-tert-butyl peroxide, copolymerization of styrene-acrylonitrile, and polymerization of 1,3-butadiene.
Aldeeb, Abdulrehman Ahmed
Tracer Testing at Dixie Valley, Nevada, Using Pyrene Tetrasulfonate Amino
Tracer Testing at Dixie Valley, Nevada, Using Pyrene Tetrasulfonate Amino Tracer Testing at Dixie Valley, Nevada, Using Pyrene Tetrasulfonate Amino G, and Fluorescein Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Tracer Testing at Dixie Valley, Nevada, Using Pyrene Tetrasulfonate Amino G, and Fluorescein Abstract A series of four tracer tests was recently conducted at the Dixie Valley, Nevada, geothermal reservoir in order to determine fluid-flow processes and to evaluate candidate tracers for use in hydrothermal systems. These tests have resulted in the first successful use of the compounds amino G and pyrenetetrasulfonate as tracers in a geothermal reservoir. The tracer candidates were subjected to simulated hydrothermal conditions in laboratory reactors at temperatures as high as 300°C in order to determine
Theoretical and Experimental Evaluation of Chemical Reactivity
Reactive chemicals are presented widely in the chemical and petrochemical process industry. Their chemical reactivity hazards have posed a significant challenge to the industries of manufacturing, storage and transportation. The accidents due to reactive chemicals have caused tremendous loss of properties and lives, and damages to the environment. In this research, three classes of reactive chemicals (unsaturated hydrocarbons, self-reacting chemicals, energetic materials) were evaluated through theoretical and experimental methods. Methylcyclopentadiene (MCP) and Hydroxylamine (HA) are selected as representatives of unsaturated hydrocarbons and self-reacting chemicals, respectively. Chemical reactivity of MCP, including isomerization, dimerization, and oxidation, is investigated by computational chemistry methods and empirical thermodynamic�energy correlation. Density functional and ab initio methods are used to search the initial thermal decomposition steps of HA, including unimolecular and bimolecular pathways. In addition, solvent effects are also examined using water cluster methods and Polarizable Continuum Models (PCM) for aqueous solution of HA. The thermal stability of a basic energetic material, Nitroethane, is investigated through both theoretical and experimental methods. Density functional methods are employed to explore the initial decomposition pathways, followed by developing detailed reaction networks. Experiments with a batch reactor and in situ GC are designed to analyze the distribution of reaction products and verify reaction mechanisms. Overall kinetic model is also built from calorimetric experiments using an Automated Pressure Tracking Adiabatic Calorimeter (APTAC). Finally, a general evaluation approach is developed for a wide range of reactive chemicals. An index of thermal risk is proposed as a preliminary risk assessment to screen reactive chemicals. Correlations are also developed between reactivity parameters, such as onset temperature, activation energy, and adiabatic time to maximum rate based on a limited number, 37 sets, of Differential Scanning Calorimeter (DSC) data. The research shows broad applications in developing reaction mechanisms at the molecular level. The methodology of reaction modeling in combination with molecular modeling can also be used to study other reactive chemical systems.
Wang, Qingsheng
Groundwater well with reactive filter pack
A method and apparatus for the remediation of contaminated soil and ground water wherein a reactive pack material is added to the annular fill material utilized in standard well construction techniques.
Gilmore, Tyler J. (Pasco, WA); Holdren, Jr., George R. (Kennewick, WA); Kaplan, Daniel I. (Richland, WA)
Catalysis and Reactivity
understanding of basic principles of surface reactivity and its control by surface modification, on identification of active sites and full characterization of their electronic...
Multiple Steady States in Azeotropic and Reactive Distillation
Introduction . Motivation Overview on the Contributions MSS in Reactive Distillation Conclusions Outline Multiple Steady States (MSS) Overview on the Contributions . The Starting Point . Consolidation . Industrial Applications . Incorporating Reactions MSS in Reactive Distillation Conclusions Outline Multiple Steady States (MSS) Overview on the Contributions MSS in Reactive Distillation . Prediction Method . MTBE Process Conclusions Outline Multiple Steady States (MSS) Overview on the Contributions MSS in Reactive Distillation Conclusions Distillation Overview . Ideal binary / multicomponent distillation . Homogeneous azeotropic distillation -- Heavy entrainer (extractive distillation) -- Intermediate entrainer -- "Boundary scheme" (ligh
Thomas E. G�ttinger
Method of uranium reclamation from aqueous systems by reactive ion exchange. [US DOE patent application; anion exchange resin of copolymerized divinyl-benzene and styrene having quarternary ammonium groups and bicarbonate ligands
A reactive ion exchange method for separation and recovery of values of uranium, neptunium, plutonium, or americium from substantially neutral aqueous systems of said metals comprises contacting said system with an effective amount of a basic anion exchange resin of copolymerized divinyl-benzene and styrene having quarternary ammonium groups and bicarbonate ligands to achieve nearly 100% sorption of said actinyl ion onto said resin and an aqueous system practically free of said actinyl ions. The method is operational over an extensive range of concentrations from about 10/sup -6/ M to 1.0 M actinyl ion and a pH range of about 4 to 7. The method has particulr application to treatment of waste streams from Purex-type nuclear fuel reprocessing facilities and hydrometallurgical processes involving U, Np, P, or Am.
Maya, L.
Hydrogeology of the Blautopf spring - Tracer tests in Blauhohle cave |
Hydrogeology of the Blautopf spring - Tracer tests in Blauhohle cave Hydrogeology of the Blautopf spring - Tracer tests in Blauhohle cave Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Hydrogeology of the Blautopf spring - Tracer tests in Blauhohle cave Author Andreas Kucha Published Publisher Not Provided, 2012 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for Hydrogeology of the Blautopf spring - Tracer tests in Blauhohle cave Citation Andreas Kucha. Hydrogeology of the Blautopf spring - Tracer tests in Blauhohle cave [Internet]. 2012. [cited 2013/10/17]. Available from: http://www.agw.kit.edu/english/blauhoele_cave.php Retrieved from "http://en.openei.org/w/index.php?title=Hydrogeology_of_the_Blautopf_spring_-_Tracer_tests_in_Blauhohle_cave&oldid=688895"
Tracer populations in the local group
, in good agreement with previous work. I go on to develop a set of tracer mass estimators that build on previous work which make use of actual (and not projected) distance and proper motion data, reflecting the amount and quality of data now available to us... ages range from 1-10 Gyr; the scale height of the population increases with age from 200 kpc to around 700 kpc and the metallicity decreases with age to around 20% solar. The typical content of this disk population are A stars, planetary nebulae...
Watkins, Laura Louise
Theoretical Investigation of Hydrogen Adsorption and dissociation on Iron and Iron Carbide Surfaces Using the ReaxFF Reactive Force Field Method
We have developed a ReaxFF reactive force field to describe hydrogen adsorption and dissociation on iron and iron carbide surfaces relevant for simulation of Fischer�Tropsch (FT) synthesis on iron catalysts. This force field enables large system (>>1000 atoms) simulations of hydrogen related reactions with iron. The ReaxFF force field parameters are trained against a substantial amount of structural and energetic data including the equations of state and heats of formation of iron and iron carbide related materials, as well as hydrogen interaction with iron surfaces and different phases of bulk iron. We have validated the accuracy and applicability of ReaxFF force field by carrying out molecular dynamics simulations of hydrogen adsorption, dissociation and recombination on iron and iron carbide surfaces. The barriers and reaction energies for molecular dissociation on these two types of surfaces have been compared and the effect of subsurface carbon on hydrogen interaction with iron surface is evaluated. We found that existence of carbon atoms at subsurface iron sites tends to increase the hydrogen dissociation energy barrier on the surface, and also makes the corresponding hydrogen dissociative state relatively more stable compared to that on bare iron. These properties of iron carbide will affect the dissociation rate of H{sub 2} and will retain more surface hydride species, thus influencing the dynamics of the FT synthesis process.
Zou, Chenyu; van Duin, Adri C.T.; Sorescu, Dan C.
Hydrogeology of the Blautopf spring - Tracer tests in Blauhohle...
2012 DOI Not Provided Check for DOI availability: http:crossref.org Online Internet link for Hydrogeology of the Blautopf spring - Tracer tests in Blauhohle cave...
Development of a Set of Inherent Particulate and Gas Tracers...
of results to the number and quality of tracer elements and if new (interfering) sources are detected. * Determine primary and secondary PM 2.5 contributions from power...
Energy.gov (U.S. Department of Energy (DOE)) Indexed Site
TRACER DETECTION TECHNOLOGY CORP. PRODUCTS AND SERVICES FOR CORPORATE AND GOVERNMENT SECURITY 3463 MAGIC DRIVE, SUITE T-19 SAN ANTONIO, TX 78229 March 29, 2009 Office of the...
A formal approach for the development of reactive systems
Context: This paper deals with the development and verification of liveness properties on reactive systems using the Event-B method. By considering the limitation of the Event-B method to invariance properties, we propose to apply the language TLA^+ ... Keywords: Event-B method, Language TLA+, Liveness properties, Reactive systems, Refinement, Verification
Olfa Mosbahi; Leila Jemni Ben Ayed; Mohamed Khalgui
A description of some of the methods used in neuroreceptor imaging to distinguish changes in receptor availability has been presented in this chapter. It is necessary to look beyond regional uptake of the tracer since uptake generally is affected by factors other than the number of receptors for which the tracer has affinity. An exception is the infusion method producing an equilibrium state. The techniques vary in complexity some requiring arterial blood measurements of unmetabolized tracer and multiple time uptake data. Others require only a few plasma and uptake measurements and those based on a reference region require no plasma measurements. We have outlined some of the limitations of the different methods. Laruelle (1999) has pointed out that test/retest studies to which various methods can be applied are crucial in determining the optimal method for a particular study. The choice of method will also depend upon the application. In a clinical setting, methods not involving arterial blood sampling are generally preferred. In the future techniques for externally measuring arterial plasma radioactivity with only a few blood samples for metabolite correction will extend the modeling options of clinical PET. Also since parametric images can provide information beyond that of ROI analysis, improved techniques for generating such images will be important, particularly for ligands requiring more than a one-compartment model. Techniques such as the wavelet transform proposed by Turkheimer et al. (2000) may prove to be important in reducing noise and improving quantitation.
Logan, J.
National Biomedical Tracer Facility. Project definition study
We request a $25 million government-guaranteed, interest-free loan to be repaid over a 30-year period for construction and initial operations of a cyclotron-based National Biomedical Tracer Facility (NBTF) in North Central Texas. The NBTF will be co-located with a linear accelerator-based commercial radioisotope production facility, funded by the private sector at approximately $28 million. In addition, research radioisotope production by the NBTF will be coordinated through an association with an existing U.S. nuclear reactor center that will produce research and commercial radioisotopes through neutron reactions. The combined facilities will provide the full range of technology for radioisotope production and research: fast neutrons, thermal neutrons, and particle beams (H{sup -}, H{sup +}, and D{sup +}). The proposed NBTF facility includes an 80 MeV, 1 mA H{sup -} cyclotron that will produce proton-induced (neutron deficient) research isotopes.
Schafer, R.
Tracer Testing At East Mesa Geothermal Area (1983) | Open Energy
Tracer Testing At East Mesa Geothermal Area (1983) Tracer Testing At East Mesa Geothermal Area (1983) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Tracer Testing At East Mesa Geothermal Area (1983) Exploration Activity Details Location East Mesa Geothermal Area Exploration Technique Tracer Testing Activity Date 1983 Usefulness not indicated DOE-funding Unknown Notes Two field experiments were conducted to develop chemical tracer procedures for use with injection-backflow testing, one on the fracture-permeability Raft River reservoir and the other on the matrix-permeability East Mesa reservoir. Results from tests conducted with incremental increases in the injection volume at both East Mesa and Raft River suggests that, for both reservoirs, permeability remained uniform with increasing distance from the
Apparatus and method for downhole injection of radioactive tracer
The disclosure relates to downhole injection of radioactive .sup.82 Br and monitoring its progress through fractured structure to determine the nature thereof. An ampule containing granular .sup.82 Br is remotely crushed and water is repeatedly flushed through it to cleanse the instrument as well as inject the .sup.82 Br into surrounding fractured strata. A sensor in a remote borehole reads progress of the radioactive material through fractured structure.
Potter, Robert M. (Los Alamos, NM); Archuleta, Jacobo R. (Espanola, NM); Fink, Conrad F. (Los Alamos, NM)
Analysis of Passive Tracer Transport as Modeled by an Atmospheric General Circulation Model
Tracers without feedback on the atmosphere are used to probe tropospheric transport. Such passive tracers are considered for two important anthropogenic sources, Europe and eastern North America. The linearity of passive tracer continuity allows ...
Mark Holzer
Experimental evaluation of an instrumented synthesis method for the real-time estimation of reactivity. Progress report, 1 July 1992--31 December 1992
Locating of leaks in water-cooled generator stator bars using perfluorocarbon tracers
Water cooled stator bars in power plant generators often fail during the maintenance cycle due to water leakage. After the hydrogen pressure in the generator shell has been released water can leak through cracks in the copper and through the insulation. Leaking bars, but not the leaks themselves, are detected with so-called ``hi-pot`` (high potential) tests where direct electrical current is applied to the stator bar windings. A study initiated by ConEd and Brookhaven`s Tracer Technology Center to explore the cause of these leakage problems to determine if the failures originate in the manufacturing process or are created in service by phase related torque stresses. To this purpose bars that had failed the hi-pot test were investigated first with the insulation in place and then stripped to the bare copper. The bars were pressurized with gases containing perfluorocarbon tracers and the magnitude and location of the leaks was detected by using tracers technology principles and instruments such as the ``double source`` method and the Dual Trap Analyzer. In the second part of the project the windings within a generator were tested in-situ for leaks during an outage using tracer principles. Recommendations are given suggesting the shut down of stator bar cooling water before hydrogen bleeding during outages and a revision of the current vent flow rate. The new standard should establish a reasonable leak rate for the stator bar windings proper and exclude leakage of pump seals and connections. Testing during the maintenance cycle in generators should include routine tracer leak detection following the hi-pot test.
Loss, W.M.; Dietz, R.N.
Water cooled stator bars in power plant generators often fail during the maintenance cycle due to water leakage. After the hydrogen pressure in the generator shell has been released water can leak through cracks in the copper and through the insulation. Leaking bars, but not the leaks themselves, are detected with so-called hi-pot'' (high potential) tests where direct electrical current is applied to the stator bar windings. A study initiated by ConEd and Brookhaven's Tracer Technology Center to explore the cause of these leakage problems to determine if the failures originate in the manufacturing process or are created in service by phase related torque stresses. To this purpose bars that had failed the hi-pot test were investigated first with the insulation in place and then stripped to the bare copper. The bars were pressurized with gases containing perfluorocarbon tracers and the magnitude and location of the leaks was detected by using tracers technology principles and instruments such as the double source'' method and the Dual Trap Analyzer. In the second part of the project the windings within a generator were tested in-situ for leaks during an outage using tracer principles. Recommendations are given suggesting the shut down of stator bar cooling water before hydrogen bleeding during outages and a revision of the current vent flow rate. The new standard should establish a reasonable leak rate for the stator bar windings proper and exclude leakage of pump seals and connections. Testing during the maintenance cycle in generators should include routine tracer leak detection following the hi-pot test.
Tracer Testing At Jemez Pueblo Area (DOE GTP) | Open Energy Informatio...
Tracer Testing At Jemez Pueblo Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Tracer Testing At Jemez Pueblo Area (DOE GTP)...
Field and numerical studies of tracer gas transport and surface gas tranfer in laterally uniform, partially stratified estuaries
Techniques for determination of reaeration rates in natural waterbodies are reviewed. The tracer gas technique for reaeration rate determination offers many advantages over other existing methods and is widely used in rivers and streams. The tracer gas method seems to be the most promising of available techniques for estuarine reaeration rate determination. The two-dimensional late-rally averaged equations describing flow and transport in estuaries are derived and discussed. A laterally averaged numerical model of estaurine hydrodynamics and transport is modified so that tracer gas releases may be simulated. Field studies conducted as a part of the study are described. Two dye releases were made in the upper Houston Ship Channel; two dye tracer gas releases were later made in the same region. The data from these studies are presented and analyzed. Mechanical mixing by shipping traffic proved to be the predominant mixing mechanism and a hindrance to further studies at that site. An intensive field study was conducted in the Colorado River estuary. Field data included velocities, salinity profiles, water surface elevations, and dye concentration data from three dye releases. The data from this study are used to calibrate and test the numerical model of estuarine tracer gas transport.
Bales, J.D.
Oxyferryl Heme Reactivity
Oxyferryl Heme Reactivity Using both Radiation and Photochemical Oxyferryl Heme Reactivity Using both Radiation and Photochemical Techniques A. M. English, T. Fox, G. Tsaprailis, C. W. Fenwick, J. F. Wishart, J. T. Hazzard, and G. Tollin Adv. Chem. Ser. 254, Ch. 6, pp. 81-98 Abstract: Flash photolysis and pulse radiolysis were used to generate reductants in situ to study the electron-transfer (ET) reactivity of the FeIV=O heme centers in myoglobin and cytochrome c peroxidase. Reduction of a5RuIII groups covalently bound to surface histidines allowed intramolecular RuII --> FeIV=O ET rates to be measured. Protonation of the oxene ligand was found to be largely rate determining in myoglobin, consistent with the lack of proton donors in its heme pocket. The large distance (21-23 Å) between surface histidines and the heme in wild-type
Reactivity of Acid Generators
Reactivity of Acid Generators for Chemically Amplified Resists with Reactivity of Acid Generators for Chemically Amplified Resists with Low-Energy Electrons Atsuro Nakano, Takahiro Kozawa, Seiichi Tagawa, Tomasz Szreder, James F. Wishart, Toshiyuki Kai and Tsutomu Shimokawa Jpn. J. Appl. Phys., 45, L197-L200 (2006). [Find paper at the Japanese Journal of Applied Physics] Abstract: In chemically amplified resists for ionizing radiations such as electron beams and extreme ultraviolet (EUV), low-energy electrons play an important role in the pattern formation processes. The reactivity of acid generators with low-energy electrons was evaluated using solvated electrons in tetrahydrofuran, which were generated by a pulsed electron beam. The rate constants of acid generators with the solvated electrons ranged from 0.6 to 1.9 x 1011 M-1s-1
Tracer Gas Transport under Mixed Convection Conditions in an Experimental
Tracer Gas Transport under Mixed Convection Conditions in an Experimental Tracer Gas Transport under Mixed Convection Conditions in an Experimental Atrium: Comparison Between Experiments and CFD Predictions Title Tracer Gas Transport under Mixed Convection Conditions in an Experimental Atrium: Comparison Between Experiments and CFD Predictions Publication Type Journal Article Year of Publication 2006 Authors Jayaraman, Buvaneswari, Elizabeth U. Finlayson, Michael D. Sohn, Tracy L. Thatcher, Phillip N. Price, Emily E. Wood, Richard G. Sextro, and Ashok J. Gadgil Journal Atmospheric Environment Volume 40 Start Page Chapter Pagination 5236-5250 Keywords airflow and pollutant transport group, atria, indoor airflow and pollutant transport, indoor environment department, indoor pollutant dispersion, mixed convection, turbulence model
Some design considerations for the proposed Dixie Valley tracer test
A tracer test for the Dixie Valley, Nevada, geothermal resource is planned for the summer of 1988, in order to study the fluid flow paths that will develop under typical operating conditions. During the test six production wells will provide the power plant with steam sufficient for generation of 60 MWe, requiring fluid production at a rate of approximately 600 kg/sec. Up to 75% by mass of the extracted fluid will be reinjected into the reservoir, using four injection wells. Tracer will be added to the injected fluid for a twenty-minute period, and subsequently the produced fluid will be monitored for the tracer. 5 refs., 9 figs., 5 tabs.
Doughty, C.; Bodvarsson, G.S.
Reactive power compensating system
The reactive power of an induction machine is compensated by providing fixed capacitors on each phase line for the minimum compensation required, sensing the current on one line at the time its voltage crosses zero to determine the actual compensation required for each phase, and selecting switched capacitors on each line to provide the balance of the compensation required.
Williams, Timothy J. (Redondo Beach, CA); El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Seattle, WA)
Reactive Power Compensating System.
The circuit was designed for the specific application of wind-driven induction generators. It has great potential for application in any situation where a varying reactive power load is present, such as with induction motors or generators, or for transmission network compensation.
Williams, Timothy J.; El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.
National Biomedical Tracer Facility: Project definition study
The Los Alamos National Laboratory is an ideal institution and New Mexico is an ideal location for siting the National Biomedical Tracer Facility (NBTF). The essence of the Los Alamos proposal is the development of two complementary irradiation facilities that combined with our existing radiochemical processing hot cell facilities and waste handling and disposal facilities provide a low cost alternative to other proposals that seek to satisfy the objectives of the NBTF. We propose the construction of a 30 MeV cyclotron facility at the site of the radiochemical facilities, and the construction of a 100 MeV target station at LAMPF to satisfy the requirements and objectives of the NBTF. We do not require any modifications to our existing radiochemical processing hot cell facilities or our waste treatment and disposal facilities to accomplish the objectives of the NBTF. The total capital cost for the facility defined by the project definition study is $15.2 M. This cost estimate includes $9.9 M for the cyclotron and associated facility, $2.0 M for the 100 MeV target station at LAMPF, and $3.3 M for design.
Heaton, R.; Peterson, E. [Los Alamos National Lab., NM (United States); Smith, P. [Smith (P.A.) Concepts and Designs (United States)
Geographic Information Systems- Tools For Geotherm Exploration, Tracers
Systems- Tools For Geotherm Exploration, Tracers Systems- Tools For Geotherm Exploration, Tracers Data Analysis, And Enhanced Data Distribution, Visualization, And Management Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Geographic Information Systems- Tools For Geotherm Exploration, Tracers Data Analysis, And Enhanced Data Distribution, Visualization, And Management Details Activities (4) Areas (3) Regions (0) Abstract: Geographic information systems (GIS) are an underused resource that can help the geothermal industry in exploration, tracer analysis, infrastructure management, and the general distribution and use of data. GIS systems are highly customizable to specific user needs and can use entire corporate data sets through a visual interface. This paper briefly documents the use of GIS in specific examples of geothermal research at the
The Dispersion of Atmospheric Tracers in Nocturnal Drainage Flows
This paper summarizes the results of a series of perfluorocarbon tracer experiments that were carried out in the Brush Creek Valley in western Colorado under the auspices of the Atmospheric Studies in Complex Terrain (ASCOT) program. The results ...
Paul H. Gudiksen; Donald L. Shearer
Tracer Advection Using Dynamic Grid Adaptation and MM5
A dynamic grid adaptation (DGA) technique is used to numerically simulate tracer transport at meso- and regional scales. A gridpoint redistribution scheme is designed to maximize heuristic characteristics of a �good� grid. The advective solver ...
John P. Iselin; William J. Gutowski; Joseph M. Prusa
A Study of Tracer Distribution Parameter Estimation from Sparse Samples
How do design parameters such as the spacing of sampling stations affect the quality of information obtained from atmospheric dispersion experiments? In large-scale experiments such as the Cross-Appalachian Tracer Experiment (CAPTEX) and the ...
Diagnosis of Subtropical Humidity Dynamics Using Tracers of Last Saturation
A technique for diagnosing the mechanisms that control the humidity in a general circulation model (GCM) or observationally derived meteorological analysis dataset is presented. The technique involves defining a large number of tracers, each of ...
Joseph Galewsky; Adam Sobel; Isaac Held
Atmospheric Dispersion and Tracer Ventilation in a Deep Mountain Valley
During September and October 1984, a major meteorological and tracer study was conducted in Colorado's Brush Creek valley. The characteristics of atmospheric dispersion during the nighttime and morning transition periods are discussed in this ...
K. Jerry Allwine
An Automated Sequential Syringe Sampler for Atmospheric Tracer Studies
The design of an improved sampler for the automatic collection of air samples during atmospheric halogenated tracer experiments is described. In this approach, each sample is collected in a small volume (20 to 150 ml) syringe using a rack and ...
Joseph P. Krasnec; David E. Demaray; Brian Lamb; Richard Benner
Can a Tracer Field Be Inverted for Velocity?
Determining flow fields and mixing rates from chemical tracer distributions is a challenging and important oceanographic problem. Thus the conclusion, that solutions obtained for underdetermined systems were �devoid of physical content�, drawn by ...
Carl Wunsch
Morning Transition Tracer Experiments in a Deep Narrow Valley
Three sulfur hexafluoride atmospheric tracer experiments were conducted during the post-sunrise temperature inversion breakup period in the deep, narrow Brush Creek Valley of Colorado. Experiments were conducted under clear, undisturbed weather ...
C. David Whiteman
Lagrangian Transport Calculations Using UARS Data. Part I. Passive Tracers
The transport of passive tracers observed by the Upper Atmosphere Research Satellite is simulated using computed three-dimensional trajectories of ? 100 000 air parcels initialized on a stratosphere grid, with horizontal winds provided by the ...
G.L. Manney; R.W. Zurek; W.A. Lahoz; R.S. Harwood; J.C. Gille; J.B. Kumer; J.L. Mergenthaler; A.E. Roche; A. O'Neill; R. Swinbank; J.W. Waters
Ventilation Rates Estimated from Tracers in the Presence of Mixing
The intimate relationship among ventilation, transit-time distributions, and transient tracer budgets is analyzed. To characterize the advective�diffusive transport from the mixed layer to the interior ocean in terms of flux we employ a ...
Timothy M. Hall; Thomas W. N. Haine; Darryn W. Waugh; Mark Holzer; Francesca Terenzi; Deborah A. LeBel
Transport of Passive Tracers in Baroclinic Wave Life Cycles
The transport of passive tracers in idealized baroclinic wave life cycles is studied using output from the National Center for Atmospheric Research Community Climate Model (CCM2). Two life cycles, LCn and LCs, are simulated, starting with ...
Elizabeth M. Stone; William J. Randel; John L. Stanford
Results of Repeat Tracer Tests at Ohaaki, NZ
During 20 years of tracer testing at Ohaaki a number of wells have been used more than once as tracer injection sites. In studying the various responses obtained it has been necessary to consider variations in the experimental test conditions before making comparisons which relate to field conditions. Some very significant changes have occurred in the field hydrology in recent years and water flow speeds as high as those encountered at Wairakei have been demonstrated.
McCabe, W.J.; Clotworthy, A.W.; Morris, C.
Thermal single-well injection-withdrawal tracer tests for determining fracture-matrix heat transfer area
Single-well injection-withdrawal (SWIW) tracer tests involve injection of traced fluid and subsequent tracer recovery from the same well, usually with some quiescent time between the injection and withdrawal periods. SWIW are insensitive to variations in advective processes that arise from formation heterogeneities, because upon withdrawal, fluid parcels tend to retrace the paths taken during injection. However, SWIW are sensitive to diffusive processes, such as diffusive exchange of conservative or reactive solutes between fractures and rock matrix. This paper focuses on SWIW tests in which temperature itself is used as a tracer. Numerical simulations demonstrate the sensitivity of temperature returns to fracture-matrix interaction. We consider thermal SWIW response to the two primary reservoir improvements targeted with stimulation, (1) making additional fractures accessible to injected fluids, and (2) increasing the aperture and permeability of pre-existing fractures. It is found that temperature returns in SWIW tests are insensitive to (2), while providing a strong signal of more rapid temperature recovery during the withdrawal phase for (1).
Pruess, K.; Doughty, C.
Grid Shunt Reactive Power Compensation
This report provides essential information on transmission grid shunt reactive power compensation, with particular focus on controllable reactive power sources such as the static var controller (SVC). Applying the information presented in this report can help electric utilities planning grid shunt reactive power compensation strategies or operating shunt reactive power compensation equipment to increase grid reliability, improve grid performance and prevent costly cascading outages. The report is intende...
The goal of this specific research task is to develop proxy tracers that mimic contaminant movement to better understand and predict contaminant fate and transport in karst aquifers. Hydrogel tracer beads are transported as a separate phase than water and can used as a proxy tracer to mimic the transport of non-aqueous phase liquids (NAPL). They can be constructed with different densities, sizes & chemical attributes. This poster describes the creation and optimization of the beads and the field testing of buoyant beads, including sampling, tracer analysis, and quantitative analysis. The buoyant beads are transported ahead of the dissolved solutes, suggesting that light NAPL (LNAPL) transport in karst may occur faster than predicted from traditional tracing techniques. The hydrogel beads were successful in illustrating this enhanced transport.
Amanda Laskoskie, Harry M. Edenborn, and Dorothy J. Vesper
Reactive Maintenance | Department of Energy
Reactive Maintenance Reactive Maintenance Reactive Maintenance October 7, 2013 - 9:40am Addthis Reactive maintenance follows a run-it-until-it-breaks strategy where no actions or efforts are taken to maintain equipment as intended by the manufacturer. Studies indicate this is still the predominant mode of maintenance for Federal facilities. Advantages Reactive maintenance advantages are a double-edged sword. Federal agencies following a purely reactive maintenance strategy can expect little expenditures for manpower or system upkeep until something breaks. However, systems do break. With new equipment, Federal agencies can expect minimal incidents of failure. However, older equipment often experiences higher failure incidents and costlier repairs. Other advantages of reactive maintenance are:
TRACER: an EXCEL workbook to calculate mean residence time in groundwater by use of tracers CFC-11, CFC-12 and tritium
An EXCEL workbook is presented for calculating the mean residence time of groundwater based on the environmental tracers, tritium, CFC-11 and CFC-12. The program TRACER is written in Visual Basic for Application language and uses piston, exponential, ... Keywords: environmental tracer, exit-age distribution, exponential model, piston flow, turnover time
Serdar Bayari
Wear Measurement of Highly Cross-linked UHMWPE using a 7Be Tracer Implantation Technique
The very low wear rates achieved with the current highly cross-linked ultrahigh molecular weight polyethylenes (UHMWPE) used in joint prostheses have proven to be difficult to measure accurately by gravimetry. Tracer methods are there- fore being explored. The purpose of this study was to perform a proof-of-concept experiment on the use of the radioactive tracer beryllium-7 (7Be) for the determination of in vitro wear in a highly cross-linked orthopedic UHMWPE. Three cross-linked and four conventional UHMWPE pins made from compression- molded GUR 1050, were activated with 109 to 1010 7Be nuclei using a new implantation setup that produced a homogenous distribution of implanted nuclei up to 8.5 lm below the surface. The pins were tested for wear in a six-station pin-on-flat appara- tus for up to 7.1 million cycles (178 km). A Germanium gamma detector was employed to determine activity loss of the UHMWPE pins at preset intervals during the wear test. The wear of the cross-linked UHMWPE pins was readily detected and esti- mated to be 17 6 3 lg per million cycles. The conventional-to- cross-linked ratio of the wear rates was 13.1 6 0.8, in the expected range for these materials. Oxidative degradation dam- age from implantation was negligible; however, a weak depend- ence of wear on implantation dose was observed limiting the number of radioactive tracer atoms that can be introduced. Future applications of this tracer technology may include the analysis of location-specific wear, such as loss of material in the post or backside of a tibial insert.
Wimmer, Markus A. [Rush Uniiv. Medical Center; Laurent, Michael P. [Rush Univ. Medical Center; Dwivedi, Yasha [Rush Univ. Medical Center; Gallardo, Luis A. [Rush Univ. Medical Center; Chipps, K. [Colorado School of Mines, Golden; Blackmon, Jeffery C [Louisiana State University; Kozub, R. L. [Tennessee Technological University; Bardayan, Daniel W [ORNL; Gross, Carl J [ORNL; Stracener, Daniel W [ORNL; Smith, Michael Scott [ORNL; Nesaraja, Caroline D [ORNL; Erikson, Luke [Colorado School of Mines, Golden; Patel, Nidhi [Colorado School of Mines, Golden; Rehm, Karl E. [Argonne National Laboratory (ANL); Ahmad, Irshad [Argonne National Laboratory (ANL); Greene, John P. [Argonne National Laboratory (ANL); Greife, Uwe [Colorado School of Mines, Golden
Natural organic compounds as tracers for biomass combustion in aerosols
Biomass combustion is an important primary source of carbonaceous particles in the global atmosphere. Although various molecular markers have already been proposed for this process, additional specific organic tracers need to be characterized. The injection of natural product organic tracers to smoke occurs primarily by direct volatilization/steam stripping and by thermal alteration based on combustion temperature. The degree of alteration increases as the burn temperature rises and the moisture content of the fuel decreases. Although the molecular composition of organic matter in smoke particles is highly variable, the molecular structures of the tracers are generally source specific. The homologous compound series and biomarkers present in smoke particles are derived directly from plant wax, gum and resin by volatilization and secondarily from pyrolysis of biopolymers, wax, gum and resin. The complexity of the organic components of smoke aerosol is illustrated with examples from controlled burns of temperate and tropical biomass fuels. Burning of biomass from temperate regions (i.e., conifers) yields characteristic tracers from diterpenoids as well as phenolics and other oxygenated species, which are recognizable in urban airsheds. The major organic components of smoke particles from tropical biomass are straight-chain, aliphatic and oxygenated compounds and triterpenoids. The precursor-to-product approach of organic geochemistry can be applied successfully to provide tracers for studying smoke plume chemistry and dispersion.
Simoneit, B.R.T. [Brookhaven National Lab., Upton, NY (United States)]|[Oregon State Univ., Corvallis, OR (United States). Coll. of Oceanic and Atmospheric Sciences; Abas, M.R. bin [Brookhaven National Lab., Upton, NY (United States)]|[Univ. of Malaya, Kuala Lumpur (Malaysia); Cass, G.R. [Brookhaven National Lab., Upton, NY (United States)]|[California Inst. of Tech., Pasadena, CA (United States). Environmental Engineering Science Dept.; Rogge, W.F. [Brookhaven National Lab., Upton, NY (United States)]|[Florida International Univ., University Park, FL (United States). Dept. of Civil and Environmental Engineering; Mazurek, M.A. [Brookhaven National Lab., Upton, NY (United States); Standley, L.J. [Academy of Natural Sciences, Avondale, PA (United States). Stroud Water Research Center; Hildemann, L.M. [Stanford Univ., CA (United States). Dept. of Civil Engineering
Method of Detecting Leakage from Geologic Formations Used to...
of carbon dioxide. PFTs had been successfully used to locate and quantify leaks within nuclear power plant generators. The method pumps the PFT tracers into the reservoirs along...
Thermal stabilities of aromatic acids as geothermal tracers
This paper reports that thirty-nine aromatic acids were tested for their suitability as geothermal tracers. The parameters of the experiments included temperatures up to 300[degrees]C for periods of up to one month in fluids of various salinities, the presence of absence of rocks, and atmospheric levels of molecular oxygen. Of the compounds tested, at least 24 are suitable as tracers in a moderate-temperature geothermal environment while 5 may be used at temperatures as high as 300[degrees]C. The compounds displayed no adsorption on the rocks used in the tests. Some of the compounds were used successfully in a major tracer test at the Dixie Valley, Nevada geothermal system.
Adams, M.C.; Moore, J.N.; Fabry, L.G.; Ahn, J.H. (Utah Univ. Research Inst., Salt Lake City, UT (United States))
Tracer Testing At Raft River Geothermal Area (1983) | Open Energy
3) 3) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Tracer Testing Activity Date 1983 Usefulness not indicated DOE-funding Unknown Exploration Basis To develop chemical tracing procedures for geothermal areas. Notes Two field experiments were conducted to develop chemical tracer procedures for use with injection-backflow testing, one on the fracture-permeability Raft River reservoir and the other on the matrix-permeability East Mesa reservoir. Results from tests conducted with incremental increases in the injection volume at both East Mesa and Raft River suggests that, for both reservoirs, permeability remained uniform with increasing distance from the well bore. Increased mixing during quiescent periods, between injection and
Interwell tracer analyses of a hydraulically fractured granitic geothermal reservoir
Field experiments using fluorescent dye and radioactive tracers (Br{sup 82} and I{sup 131}) have been employed to characterize a hot, low-matrix permeability, hydraulically-fractured granitic reservoir at depths of 2440 to 2960 m (8000 to 9700 ft). Tracer profiles and residence time distributions have been used to delineate changes in the fracture system, particularly in diagnosing pathological flow patterns and in identifying new injection and production zones. The effectiveness of one- and two-dimensional theoretical dispersion models utilizing single and multiple porous, fractured zones with velocity and formation dependent effects are discussed with respect to actual field data.
Tester, J.W.; Potter, R.M.; Bivins, R.L.
Preliminary assessment of halogenated alkanes as vapor-phase tracers
New tracers are needed to evaluate the efficiency of injection strategies in vapor-dominated environments. One group of compounds that seems to meet the requirements for vapor-phase tracing are the halogenated alkanes (HCFCs). HCFCs are generally nontoxic, and extrapolation of tabulated thermodynamic data indicate that they will be thermally stable and nonreactive in a geothermal environment. The solubilities and stabilities of these compounds, which form several homologous series, vary according to the substituent ratios of fluorine, chlorine, and hydrogen. Laboratory and field tests that will further define the suitability of HCFCs as vapor-phase tracers are under way.
Adams, Michael C.; Moore, Joseph N.; Hirtz, Paul
Complements existing methods Summary: The trend toward production of hydrocarbons from unconventional reservoirs (tight gas, shale oilgas) has caused a large increase in the...
Effects from influent boundary conditions on tracer migration and spatial variability features in intermediate-scale experiments
In previous unsaturated transport studies at Los Alamos dispersion coefficients were estimated to be higher close to the tracer source than at greater distances from the source. Injection of tracers through discrete influent outlets could have accounted for those higher dispersions. Also, a lack of conservation of mass of the tracers was observed and suspected to be due to spatial variability in transport. In the present study experiments were performed under uniform influent (ponded) conditions in which breakthrough of tracers was monitored at four locations at each of four depths. All other conditions were similar to those of the unsaturated transport experiments. A comparison of results from these two sets of experiments indicates differences in the parameter estimates. Estimates were made for the dispersion coefficient and the retardation factor by the one-dimensional steady flow computer code, CFITIM. Estimates were also made for mass and for velocity and the dispersion coefficient by the method of moments. The dispersion coefficient decreased with depth under discrete influent application and increased with depth under ponded influent application. Retardation was predicted better under the discrete influent application than under ponded influent application. Differences in breakthroughs and in estimated parameters among locations at the same depth were observed under ponded influent application. Those differences indicate that there is a lack of conservation of mass as well as significant spatial variability across the experimental domain. 14 refs., 9 figs., 8 tabs.
Fuentes, H.R.; Polzer, W.L.; Springer, E.P.
Using a combination of two models in tracer simulations
The use of a combination of two models, a Lagrangian meso-scale model and a long-range transport Eulerian model, in a model for studying the air pollution caused by a single but strong emission source is discussed. It is explained why it is worthwhile ... Keywords: Accidental releases, Advection, Animation, Chernobyl, Diffusion, ETEX, Tracer models, Visualization
J. Brandt; T. Mikkelsen; S. Thykier-Nielsen; Z. Zlatev
Tracer testing at Soultz-sous-Forts (France) using naphthalene
: · EPS1 fully cored exploration · GPK-1 preliminary injection tests · GPK-3 injection well · GPK-2 and future GPK-4 production wells 3.6 km continuous logs: Caliper, Spectral GR, UBI (5100m) #12;EHDRA-2 (July 2000) > Water injection · 26,800 m3 of fresh water and 1,000 m3 of heavy brine > Tracer
Reactive rules on the web
Reactive rules are used for programming rule-based, reactive systems, which have the ability to detect events and respond to them automatically in a timely manner. Such systems are needed on the Web for bridging the gap between the existing, passive ...
Bruno Berstel; Philippe Bonnard; Fran�ois Bry; Michael Eckert; Paula-Lavinia P?tr�njan
Solving Underdetermined Tracer Inverse Problems by Spatial Smoothing and Cross Validation
Tracer conservation equations may be inverted to determine the flow field and macroscopic diffusion coefficients from known tracer distributions. An underdetermined system leads to an infinite number of possible solutions. The solution that is ...
Peter C. McIntosh; George Veronis
Dispersion of Perfluorocarbon Tracers within the Salt Lake Valley during VTMX 2000
Six perfluorocarbon tracer experiments were conducted in Salt Lake City, Utah, during October 2000 as part of the Vertical Transport and Mixing (VTMX) field campaign. Four tracers were released at different sites to obtain information on ...
Jerome D. Fast; K. Jerry Allwine; Russell N. Dietz; Kirk L. Clawson; Joel C. Torcolini
Relationships between Tracer Ages and Potential Vorticity in Unsteady Wind-Driven Circulations
The relationships between different tracer ages and between tracer age and potential vorticity are examined by simulating barotropic double-gyre circulations. The unsteady model flow crudely represents aspects of the midlatitude, middepth ocean ...
Hong Zhang; Thomas W. N. Haine; Darryn W. Waugh
The Roles of Langmuir Circulations in the Dispersion of Surface Tracers
A hierarchy of theoretical and numerical models for the dispersion of discrete floating tracers on lakes and oceans is presented. Central to these models is the role of Langmuir circulations, which concentrate tracers into narrow windrows this ...
Alan J. Faller; Stephen J. Auer
Numerical Simulations of Airflows and Tracer Transport in the Southwestern United States
Project MOHAVE (Measurement of Haze and Visual Effects) produced a unique set of tracer data over the southwestern United States. During the summer of 1992, a perfluorocarbon tracer gas was released from the Mohave Power Project (MPP), a large ...
Tetsuji Yamada
Federal Energy Management Program: Reactive Maintenance
Reactive Reactive Maintenance to someone by E-mail Share Federal Energy Management Program: Reactive Maintenance on Facebook Tweet about Federal Energy Management Program: Reactive Maintenance on Twitter Bookmark Federal Energy Management Program: Reactive Maintenance on Google Bookmark Federal Energy Management Program: Reactive Maintenance on Delicious Rank Federal Energy Management Program: Reactive Maintenance on Digg Find More places to share Federal Energy Management Program: Reactive Maintenance on AddThis.com... Sustainable Buildings & Campuses Operations & Maintenance Federal Requirements Program Management Commissioning Metering Computerized Maintenance Management Systems Maintenance Types Reactive Preventive Predictive Reliability-Centered Major Equipment Types
A Tariff for Reactive Power
Two kinds of power are required to operate an electric power system: real power, measured in watts, and reactive power, measured in volt-amperes reactive or VARs. Reactive power supply is one of a class of power system reliability services collectively known as ancillary services, and is essential for the reliable operation of the bulk power system. Reactive power flows when current leads or lags behind voltage. Typically, the current in a distribution system lags behind voltage because of inductive loads such as motors. Reactive power flow wastes energy and capacity and causes voltage droop. To correct lagging power flow, leading reactive power (current leading voltage) is supplied to bring the current into phase with voltage. When the current is in phase with voltage, there is a reduction in system losses, an increase in system capacity, and a rise in voltage. Reactive power can be supplied from either static or dynamic VAR sources. Static sources are typically transmission and distribution equipment, such as capacitors at substations, and their cost has historically been included in the revenue requirement of the transmission operator (TO), and recovered through cost-of-service rates. By contrast, dynamic sources are typically generators capable of producing variable levels of reactive power by automatically controlling the generator to regulate voltage. Transmission system devices such as synchronous condensers can also provide dynamic reactive power. A class of solid state devices (called flexible AC transmission system devices or FACTs) can provide dynamic reactive power. One specific device has the unfortunate name of static VAR compensator (SVC), where 'static' refers to the solid state nature of the device (it does not include rotating equipment) and not to the production of static reactive power. Dynamic sources at the distribution level, while more costly would be very useful in helping to regulate local voltage. Local voltage regulation would reduce system losses, increase circuit capacity, increase reliability, and improve efficiency. Reactive power is theoretically available from any inverter-based equipment such as photovoltaic (PV) systems, fuel cells, microturbines, and adjustable-speed drives. However, the installation is usually only economical if reactive power supply is considered during the design and construction phase. In this report, we find that if the inverters of PV systems or the generators of combined heat and power (CHP) systems were designed with capability to supply dynamic reactive power, they could do this quite economically. In fact, on an annualized basis, these inverters and generators may be able to supply dynamic reactive power for about $5 or $6 per kVAR. The savings from the local supply of dynamic reactive power would be in reduced losses, increased capacity, and decreased transmission congestion. The net savings are estimated to be about $7 per kVAR on an annualized basis for a hypothetical circuit. Thus the distribution company could economically purchase a dynamic reactive power service from customers for perhaps $6/kVAR. This practice would provide for better voltage regulation in the distribution system and would provide an alternate revenue source to help amortize the cost of PV and CHP installations. As distribution and transmission systems are operated under rising levels of stress, the value of local dynamic reactive supply is expected to grow. Also, large power inverters, in the range of 500 kW to 1 MW, are expected to decrease in cost as they become mass produced. This report provides one data point which shows that the local supply of dynamic reactive power is marginally profitable at present for a hypothetical circuit. We expect that the trends of growing power flow on the existing system and mass production of inverters for distributed energy devices will make the dynamic supply of reactive power from customers an integral component of economical and reliable system operation in the future.
Kueck, John D [ORNL; Kirby, Brendan J [ORNL; Li, Fangxing [ORNL; Tufon, Christopher [Pacific Gas and Electric Company; Isemonger, Alan [California Independent System Operator
Chemical tracer test at the Dixie Valley geothermal field, Nevada. Geothermal Reservoir Technology research program
In the injection test described, chemical tracers established the fluid flow between one injection well and one production well. Measured tracer concentrations, calculated flow rates, sampling schedules, and the daily events of the tracer test are documented. This experiment was designed to test the application of organic tracers, to further refine the predictive capability of the reservoir model, and to improve the effectiveness of Oxbow`s injection strategy.
Adams, M.C.; Moore, J.N. [Utah Univ. Research Inst., Salt Lake City, UT (United States); Benoit, W.R. [Oxbow Geothermal Corp., Reno, NV (United States); Doughty, C.; Bodvarsson, G.S. [Lawrence Berkeley Lab., CA (United States)
Prognostic Prediction of Tracer Dispersion for the Diablo Canyon Experiments on August 31, September 2, and September 4, 1986
COAMPS/LODI simulations of the tracer experiments at Diablo Canyon on August 31, September 2, and September 4, 1986 had mixed results. Simulated tracer concentrations on August 31 differed significantly from the measured concentrations. The model transported SF{sub 6} too far south and did not predict transport of SF{sub 6} north along highway 101 or into See Canyon. Early in the day the model rapidly transported SF{sub 6} away from the release point while observations suggested the tracer stayed close to Diablo Canyon for 1-2 hours. For September 2, simulations agreed very well with the measurements. The model accurately predicted the change of wind direction from north northwest to east northeast at the release point. It also predicted the advection of tracer over Mot-r-0 Bay and through the Los Osos Valley toward San Luis Obispo in excellent agreement with the observations. On September 4, the calculated transport of SF{sub 6} from Diablo Canyon had defects similar to those on August 31, a trajectory too far south and limited intrusion of tracer north along highway 101. Conversely, simulations of the Freon release from Los Osos Cemetery on September 4 corresponded well with observations. Since the simulations used only global meteorological data and no local winds for input, even the limited success of COAMPS/LODI is a favorable result. COAMPS's inability to generate southerly winds through the highway 101 corridor on August 31 and September 4 is a symptom of its underestimate of the sea breeze. The weak sea breeze correlates with a small diurnal range of air temperature possibly associated with underestimates of surface solar heating and/or overestimates of surface wetness. Improvement of COAMPS/LODI simulations requires development of new data assimilation techniques to use the local surface and low altitude wind and temperature measurements. Also, quantitative methods are needed to assess the accuracy of the models.
Molenkamp, C.R.
A toolkit for groundwater mean residence time interpretation with gaseous tracers
An analytical Excel-based toolkit called Gas-Tracer-Interpretation (GTI) was developed for determining mean residence time (MRT) of groundwater samples and for validating conceptual model assumptions. This novel data interpretation toolkit improves data ... Keywords: Environmental tracer, Environmental tracers concentrations in water, Groundwater dating, Lumped-parameter modeling, Water age
Pablo Fernando D�vila, Christoph K�lls, Markus Weiler
Modeling of CBM production, CO{sub 2} injection, and tracer movement at a field CO{sub 2} sequestration site
Sequestration of carbon dioxide in unmineable coal seams is a potential technology mainly because of the potential for simultaneous enhanced coalbed methane production (ECBM). Several pilot tests have been performed around the globe leading to mixed results. Numerous modeling efforts have been carried out successfully to model methane production and carbon dioxide (CO{sub 2}) injection. Sensitivity analyses and history matching along with several optimization tools were used to estimate reservoir properties and to investigate reservoir performance. Geological and geophysical techniques have also been used to characterize field sequestration sites and to inspect reservoir heterogeneity. The fate and movement of injected CO{sub 2} can be determined by using several monitoring techniques. Monitoring of perfluorocarbon (PFC) tracers is one of these monitoring technologies. As a part of this monitoring technique, a small fraction of a traceable fluid is added to the injection wellhead along with the CO{sub 2} stream at different times to monitor the timing and location of the breakthrough in nearby monitoring wells or offset production wells. A reservoir modeling study was performed to simulate a pilot sequestration site located in the San Juan coal basin of northern New Mexico. Several unknown reservoir properties at the field site were estimated by modeling the coal seam as a dual porosity formation and by history matching the methane production and CO{sub 2} injection. In addition to reservoir modeling of methane production and CO{sub 2} injection, tracer injection was modeled. Tracers serve as a surrogate for determining potential leakage of CO{sub 2}. The tracer was modeled as a non-reactive gas and was injected into the reservoir as a mixture along with CO{sub 2}. Geologic and geometric details of the field site, numerical modeling details of methane production, CO{sub 2} injection, and tracer injection are presented in this paper. Moreover, the numerical predictions of the tracer arrival times were compared with the measured field data. Results show that tracer modeling is useful in investigating movement of injected CO{sub 2} into the coal seam at the field site. Also, such new modeling techniques can be utilized to determine potential leakage pathways, and to investigate reservoir anisotropy and heterogeneity.
Siriwardane, Hema J.; Bowes, Benjamin D.; Bromhal, Grant S.; Gondle, Raj K.; Wells, Arthur W.; Strazisar, Brian R.
Reactivity of heat treated chars
Reactivities of a number of chars produced from American coals varying in rank from lignite to anthracite have been measured in air, CO/sub 2/, steam and H/sub 2/. The variables chosen for the study were: rank of the parent coal, inorganic matter content, particle size, reaction temperature and pressure as well as heat treatment conditions used during char preparation. In all gasification atmospheres studied, reactivity plots for different chars are essentially of the same general shape and have three distinct regions. The reaction rate first increases slowly with time. The plot then goes through a maximum in slope, followed by a lengthy region of decreasing slope as burn-off approaches 100 percent. The shape of the burn-off curves can be explained on the basis of what is known about the development of porosity and surface area in microporous chars as they undergo gasification. Using an adjustable time parameter, equations have been developed which successfully correlate the reactivity data. Char reactivity decreases, in general, with increase in rank of the parent coal. Reactivities of chars in air, CO/sub 2/ and steam increase over 150-fold in going from a low volatile bituminous to a lignite parent coal; the spread in char reactivities in H/sub 2/ is only 30-fold. Removal of inorganic matter from coal precursors prior to their charring or from chars produced from the raw coals has a marked effect on char reactivity and surface area. Removal of inorganic matter (by acid washing) decreases, in general, reactivity of chars produced from lower rank coals, whereas reactivities of chars derived from higher rank coals increase.
Mahajan, O. P.; Walker, Jr., P. L.
Method for reactivating catalysts and a method for recycling ...
Patent Number: 7,407,905: Issued: August 5, 2008: Official Filing: View the Complete Patent at the US Patent & Trademark Office: Lab: Idaho ...
A Spreadsheet Program for Two-Well Tracer Test Data Analysis
Two-well tracer tests are often conducted to investigate subsurface solute transport in the field. Analyzing breakthrough curves in extraction and monitoring wells using numerical methods is nontrivial due to highly nonuniform flow conditions. We extended approximate analytical solutions for the advection-dispersion equation for an injection-extraction well doublet in a homogeneous confined aquifer under steady-state flow conditions for equal injection and extraction rates with no transverse dispersion and negligible ambient flow, and implemented the solutions in Microsoft Excel using Visual Basic for Application (VBA). Functions were implemented to calculate concentrations in extraction and monitoring wells at any location due to a step or pulse injection. Type curves for a step injection were compared with those calculated by numerically integrating the solution for a pulse injection. The results from the two approaches are similar when the dispersivity is small. As the dispersivity increases, the latter was found to be more accurate but requires more computing time. The code was verified by comparing the results with published-type curves and applied to analyze data from the literature. The method can be used as a first approximation for two-well tracer test design and data analysis, and to check accuracy of numerical solutions. The code and example files are publicly available.
Tang, Guoping [ORNL; Watson, David [ORNL; Parker, Jack C. [University of Tennessee, Knoxville (UTK); Brooks, Scott C [ORNL
Microfluidic Investigation of Tracer Dye Diffusion in Alumina Nanofluids
Nanofluids, a new class of fluids engineered by suspending nanometer-sized particles in a host liquid, are offered as a new strategy in order to improve heat and mass transfer efficiency. My research was motivated by previous exciting studies on enhanced mass diffusion and the possibility of tailoring mass transport by direct manipulation of molecular diffusion. Therefore, a microfluidic approach capable of directly probing tracer diffusion between nanoparticle-laden fluid streams was developed. Under conditions matching previously reported studies, strong complexation interactions between the dye and nanoparticles at the interface between fluid streams was observed. When the tracer dye and surfactant were carefully chosen to minimize the collective effects of the interactions, no significant change in tracer dye diffusivity was observed in the presence of nanoparticles. Next, adapting tracer dyes for studies involving colloidal nanomaterials was explored. Addition of these charged tracers poses a myriad of challenges because of their propensity to disrupt the delicate balance among physicochemical interactions governing suspension stability. Here it was shown how important it is to select the compatible combinations of dye, nanoparticle, and stabilizing surfactant to overcome these limitations in low volume fraction (< 1 vol%) aqueous suspensions of Al2O3 nanoparticles. A microfluidic system was applied as a stability probe that unexpectedly revealed how rapid aggregation could be readily triggered in the presence of local chemical gradients. Suspension stability was also assessed in conjunction with coordinated measurements of zeta potential, steady shear viscosity and bulk thermal conductivity. These studies also guided our efforts to prepare new refrigerant formulations containing dispersed nanomaterials, including graphene nanosheets, carbon nanotubes and metal oxide and nitride. The influence of key parameters such as particle type, size and volume fraction on the suspension's thermal conductivity was investigated using a standard protocol. Our findings showed that thermal conductivity values of carbon nanotube and graphene nanosheet suspensions were higher than TiO2 nanoparticles, despite some nanoparticles with large particle sizes provided noticeable thermal conductivity enhancements. Significantly, the graphene containing suspensions uniquely matched the thermal conductivity enhancements attained in nanotube suspensions without accompanying viscosity, thus making them an attractive new coolant for demanding applications such as electronics and reactor cooling.
Ozturk, Serdar 1979-
A flux-form version of the conservative semi-Lagrangian multi-tracer transport scheme (CSLAM) on the cubed sphere grid
A conservative semi-Lagrangian cell-integrated transport scheme (CSLAM) was recently introduced, which ensures global mass conservation and allows long timesteps, multi-tracer efficiency, and shape preservation through the use of reconstruction filtering. ... Keywords: Advection, Conservation, Cubed-sphere, Flux-form, Monotonicity, Piecewise parabolic method, Semi-Lagrangian
Lucas M. Harris; Peter H. Lauritzen; Rashmi Mittal
Variational Assimilation of GOME Total-Column Ozone Satellite Data in a 2D Latitude�Longitude Tracer-Transport Model
A four-dimensional data-assimilation method is described to derive synoptic ozone fields from total-column ozone satellite measurements. The ozone columns are advected by a 2D tracer-transport model, using ECMWF wind fields at a single pressure ...
H. J. Eskes; A. J. M. Piters; P. F. Levelt; M. A. F. Allaart; H. M. Kelder
A Microsoft Excel Program for Two-Well Tracer Test Data Analysis
Two-well tracer tests are often conducted to investigate subsurface solute transport in the field. Analyzing breakthrough curves in the extraction and monitoring wells using numerical methods is nontrivial due to highly nonuniform flow conditions. We extended, and implemented analytical solutions for the convection-dispersion equation for an injection-extraction well-duplet in a homogeneous confined aquifer under steady state conditions. Functions were provided to calculate the concentrations in the extraction and monitoring wells at any location due to a step or pulse injection. Type curves for a step injection were compared with those calculated by numerically integrating the solution for a pulse injection. The results from the two approaches are similar when the dispersivity is small. As the dispersivity increases, the latter was found to be more accurate but requires more computing time. The code was verified by comparing the results with published type curves and applied to analyze data from the literature. It can be used as a first approximation for two-well tracer test data analysis, and to check accuracy of numerical solutions. The code and example files are publically-available.
Tang, Guoping [ORNL; Watson, David B [ORNL; Parker, Jack C. [University of Tennessee, Knoxville (UTK); Brooks, Scott C [ORNL
Abstract: The biodegradabilities of poly(butylene succinate) (PBS) powders in a controlled compost at 58 �C have been studied using a Microbial Oxidative Degradation Analyzer (MODA) based on the ISO 14855-2 method, entitled �Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions�Method by analysis of evolved carbon dioxide�Part 2: Gravimetric measurement of carbon dioxide evolved in a laboratory-scale test�. The evolved CO2 was trapped by an additional aqueous Ba(OH)2 solution. The trapped BaCO3 was transformed into graphite via a serial vaporization and reduction reaction using a gas-tight tube and vacuum manifold system. This graphite was analyzed by accelerated mass spectrometry (AMS) to determine the percent modern carbon [pMC (sample)] based on the 14 C radiocarbon concentration. By using the theory that pMC (sample) was the sum of the pMC (compost) (109.87%) and pMC (PBS) (0%) as the respective ratio in the determined period, the CO2 (respiration) was calculated from only one reaction vessel. It was found that the biodegradabilities determined by the CO2 amount from PBS in the sample vessel were about 30 % lower than those based on the ISO method. These differences between the
Masao Kunioka; Fumi Ninomiya; Masahiro Funabashi
Interpretation of Colloid-Homologue Tracer Test 10-03, Including Comparisons to Test 10-01
This presentation covers the interpretations of colloid-homologue tracer test 10-03 conducted at the Grimsel Test Site, Switzerland, in 2010. It also provides a comparison of the interpreted test results with those of tracer test 10-01, which was conducted in the same fracture flow system and using the same tracers than test 10-03, but at a higher extraction flow rate. A method of correcting for apparent uranine degradation in test 10-03 is presented. Conclusions are: (1) Uranine degradation occurred in test 10-03, but not in 10-01; (2) Uranine correction based on apparent degradation rate in injection loop in test 11-02 seems reasonable when applied to data from test 10-03; (3) Colloid breakthrough curves quite similar in the two tests with similar recoveries relative to uranine (after correction); and (4) Much slower apparent desorption of homologues in test 10-03 than in 10-01 (any effect of residual homologues from test 10-01 in test 10-03?).
Reimus, Paul W. [Los Alamos National Laboratory
Tracer Recovery and Mixing from Two Geothermal Injection-Backflow Studies |
Tracer Recovery and Mixing from Two Geothermal Injection-Backflow Studies Tracer Recovery and Mixing from Two Geothermal Injection-Backflow Studies Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Tracer Recovery and Mixing from Two Geothermal Injection-Backflow Studies Details Activities (2) Areas (2) Regions (0) Abstract: Injection-backflow tracer testing on a single well is not a commonly used procedure for geothermal reservoir evaluation, and, consequently, there is little published information on the character or interpretation of tracer recovery curves. Two field experiments were conducted to develop chemical tracer procedures for use with injection-backflow testing, one on the fracture-permeability Raft River reservoir and the other on the matrix-permeability East Mesa reservoir. Results from tests conducted with incremental increases in the injection
Three conservative tracer tests have been conducted through the Bridge Fault fracture zone at the Raft River Geothermal (RRG) site. All three tests were conducted between injection well RRG-5 and production wells RRG-1 (790 m distance) and RRG-4 (740 m distance). The injection well is used during the summer months to provide pressure support to the production wells. The first test was conducted in 2008 using 136 kg of fluorescein tracer. Two additional tracers were injected in 2010. The first 2010 tracer injected was 100 kg fluorescein disodium hydrate salt on June, 21. The second tracer (100 kg 2,6-naphthalene disulfonic acid sodium salt) was injected one month later on July 21. Sampling of the two productions wells is still being performed to obtain the tail end of the second 2010 tracer test. Tracer concentrations were measured using HPLC with a fluorescence detector. Results for the 2008 test, suggest 80% tracer recover at the two production wells. Of the tracer recovered, 85% of tracer mass was recovered in well RRG-4 indicating a greater flow pathway connection between injection well and RRG-4 than RRG-1. Fluorescein tracer results appear to be similar between the 2008 and 2010 tests for well RRG-4 with peak concentrations arriving approximately 20 days after injection despite the differences between the injection rates for the two tests (~950 gpm to 475 gpm) between the 2008 and 2010. The two 2010 tracer tests will be compared to determine if the results support the hypothesis that rock contraction along the flow pathway due to the 55 oC cooler water injection alters the flow through the ~140 oC reservoir.
Earl D Mattson; Mitchell Plummer; Carl Palmer; Larry Hull; Samantha Miller; Randy Nye
Testing of perfluorocarbon gas tracers (PFT) on a subsurface barrier with known flaws was conducted at the Waldo Test Site operated by Science and Engineering Associates, Inc (SEA). The tests involved the use of five unique PFTs with a different tracer injected along the interior of each wall of the barrier. A fifth tracer was injected exterior to the barrier to examine the validity of diffusion controlled transport of the PFTs. The PFTs were injected for three days at a nominal flow rate of 15 cm{sup 3}/min and concentrations in the range of a few hundred ppm. Approximately 65 liters of air laced with tracer was injected for each tracer. The tracers were able to accurately detect the presence of the engineered flaws. Two flaws were detected on the north and east walls, and one flaw was detected on the south and west walls. In addition, one non-engineered flaw at the seam between the north and east walls was also detected. The use of multiple tracers provided independent confirmation of the flaws and permitted a distinction between tracers arriving at a monitoring port after being released from a nearby flaw and non-engineered flaws. The PFTs detected the smallest flaw, 0.5 inches in diameter. Visual inspection of the data showed excellent agreement with the known flaw locations and the relative size of the flaws was accurately estimated. Simultaneous with the PFT tests, SEA conducted tests with another gas tracer sulfur hexafluoride (SF{sub 6}).
USE OF NATURALLY-OCCURRING TRACERS TO MONITOR TWO-PHASE CONDITIONS IN THE COSO EGS PROJECT Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: USE...
Rapid measurements and mapping of tracer gas concentrations in a large indoor space
Measurements of tracer gas dispersion are useful as a meansvisualization measurements of gas dispersion in large indoorcharacteristics of the gas dispersion. Figure 4 shows the
Fischer, M.L.
Treating water-reactive wastes
Some compounds and elements, such as lithium hydride, magnesium, sodium, and calcium react violently with water to generate much heat and produce hydrogen. The hydrogen can ignite or even form an explosive mixture with air. Other metals may react rapidly only if they are finely divided. Some of the waste produced at Los Alamos National Laboratory includes these metals that are contaminated with radioactivity. By far the greatest volume of water-reactive waste is lithium hydride contaminated with depleted uranium. Reactivity of the water-reactive wastes is neutralized with an atmosphere of humid nitrogen, which prevents the formation of an explosive mixture of hydrogen and air. When we adjust the temperature of the nitrogen and the humidifier, the nitrogen can be more or less humid, and the rate of reaction can be adjusted and controlled. Los Alamos has investigated the rates of reaction of lithium hydride as a function of the temperature and humidity, and, as anticipated, they in with in temperature and humidity. Los Alamos will investigate other variables. For example, the nitrogen flow will be optimized to conserve nitrogen and yet keep the reaction rates high. Reaction rates will be determined for various forms of lithium waste, from small chips to powder. Bench work will lead to the design of a skid-mounted process for treating wastes. Other water-reactive wastes will also be investigated.
Lussiez, G.W.
Estimation of tracer diffusion coefficients of ions in aqueous solution
Equations are given for estimating tracer diffusion coefficients D/sub i//sup 0/ of ions at infinite dilution in terms of limiting ionic conductances ..lambda../sub i//sup 0/. Also given are generalized Nernst-Hartley equations for binary and multicomponent diffusion coefficients D/sup 0/ and D/sub ij//sup 0/, respectively, at infinite dilution. Data, estimates, and correlations for ..lambda../sub i//sup 0/ at 25/sup 0/C and other temperatures are discussed. Estimated values of ..lambda../sub i//sup 0/ are tabulated from 0-300/sup 0/C for ions of waste isolation interest and for ions of economic interest in geothermal brines. Estimates of their tracer diffusion coefficients at infinite dilution are tabulated. A rule of thumb, good to a factor of 2, is presented. Very limited data (available only at 25/sup 0/C) indicate that D/sub i//D/sub i//sup 0/ generally declines as the concentration of salt or supporting electrolyte increases. 6 figures, 2 tables.
Miller, D.G.
We explore the use of efficient streamline-based simulation approaches for modeling and analysis partitioning interwell tracer tests in heterogeneous and fractured hydrocarbon reservoirs. We compare the streamline-based history matching techniques developed during the first two years of the project with the industry standard assisted history matching. We enhance the widely used assisted history matching in two important aspects that can significantly improve its efficiency and effectiveness. First, we utilize streamline-derived analytic sensitivities to relate the changes in reservoir properties to the production response. These sensitivities can be computed analytically and contain much more information than that used in the assisted history matching. Second, we utilize the sensitivities in an optimization procedure to determine the spatial distribution and magnitude of the changes in reservoir parameters needed to improve the history-match. By intervening at each iteration during the optimization process, we can retain control over the history matching process as in assisted history matching. This allows us to accept, reject, or modify changes during the automatic history matching process. We demonstrate the power of our method using two field examples with model sizes ranging from 10{sup 5} to 10{sup 6} grid blocks and with over one hundred wells. We have also extended the streamline-based production data integration technique to naturally fractured reservoirs using the dual porosity approach. The principal features of our method are the extension of streamline-derived analytic sensitivities to account for matrix-fracture interactions and the use of our previously proposed generalized travel time inversion for history matching. Our proposed workflow has been demonstrated by using both a dual porosity streamline simulator and a commercial finite difference simulator. Our approach is computationally efficient and well suited for large scale field applications in naturally fractured reservoirs with changing field conditions. This considerably broadens the applicability of the streamline-based analysis of tracer data and field production history for characterization of heterogeneous and fractured reservoirs.
Environmental Management, Inc. It has been subject to the Agency�s peer and administrative review, and it has been approved for publication as an EPA document. The opinions, findings, and conclusions expressed herein are those of the contractor and not necessarily those of the EPA or other cooperating agencies. Mention of company or product names is not to be construed as an endorsement by the agency. Foreword The U.S. Environmental Protection Agency is charged by Congress with protecting the Nation�s land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to formulate and implement actions leading to a compatible balance between human activities and the ability of natural systems to support and nurture life. To meet this mandate, EPA�s research program is providing data and technical support for solving environmental problems today and building a science knowledge base necessary to manage our ecological resources wisely, understand how pollutants affect our health, and prevent or reduce environmental risks in the future. The National Risk Management Research Laboratory is the Agency�s center for investigation of technological and management approaches for reducing risks from threats to human health and the environment. The focus of the Laboratory�s research program is on methods for the prevention and control of pollution to air, land, water and subsurface resources; protection of water quality in public water systems; remediation of contaminated sites and ground water; and prevention and control of indoor air pollution. The goal of this research effort is to catalyze development and implementation of innovative, cost-effective environmental technologies;
unknown authors
Definition: Reactive Power | Open Energy Information
Reactive Power Reactive Power Jump to: navigation, search Dictionary.png Reactive Power The portion of electricity that establishes and sustains the electric and magnetic fields of alternating-current equipment. Reactive power must be supplied to most types of magnetic equipment, such as motors and transformers. It also must supply the reactive losses on transmission facilities. Reactive power is provided by generators, synchronous condensers, or electrostatic equipment such as capacitors and directly influences electric system voltage. It is usually expressed in kilovars (kvar) or megavars (Mvar).[1] View on Wikipedia Wikipedia Definition In electric power transmission and distribution, volt-ampere reactive (var) is a unit used to measure reactive power in an AC electric
Particle Swarm Optimization Based Reactive Power Optimization
Reactive power plays an important role in supporting the real power transfer by maintaining voltage stability and system reliability. It is a critical element for a transmission operator to ensure the reliability of an electric system while minimizing the cost associated with it. The traditional objectives of reactive power dispatch are focused on the technical side of reactive support such as minimization of transmission losses. Reactive power cost compensation to a generator is based on the incurred cost of its reactive power contribution less the cost of its obligation to support the active power delivery. In this paper an efficient Particle Swarm Optimization (PSO) based reactive power optimization approach is presented. The optimal reactive power dispatch problem is a nonlinear optimization problem with several constraints. The objective of the proposed PSO is to minimize the total support cost from generators and reactive compensators. It is achieved by maintaining the whole system power loss as minimum...
Sujin, P R; Linda, M Mary
Engine combustion control via fuel reactivity stratification
A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter. By appropriately choose the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot).
Reitz, Rolf Deneys; Hanson, Reed M; Splitter, Derek A; Kokjohn, Sage L
Directional Reactive Power Ground Plane Transmission
Directional Reactive Power Ground Plane Transmission Technology Summary ... The invention can transmit electrical power through the surface of the ...
Reactive and Catalytic Air Purification Materials - Energy ...
Biomass and Biofuels; Building Energy Efficiency; Electricity Transmission; ... Target selectivity can be controlled through selection of reactive components.
Partnering Today: Technology Transfer Highlights Reactive ...
THE LLNL TECHNOLOGY COMPANY PRODUCT Partnering Today: Technology Transfer Highlights Reactive NanoTechnologies Inc.: Temperature-controlled Precision Bonding
Gamma Survey of a Permeable Reactive Barrier at Monticello, Utah...
Gamma Survey of a Permeable Reactive Barrier at Monticello, Utah Gamma Survey of a Permeable Reactive Barrier at Monticello, Utah Gamma Survey of a Permeable Reactive Barrier at...
Nuclear methods in environmental and energy research
The topics considered in the seven sessions were nuclear methods in atmospheric research; nuclear and atomic methodology; nuclear methods in tracer applications; energy exploration, production, and utilization; nuclear methods in environmental monitoring; nuclear methods in water research; and nuclear methods in biological research. Individual abstracts were prepared for each paper. (JSR)
Vogt, J.R. (ed.)
High-power I-V curve tracer employing a capacitive load
A portable, photovoltaic voltage versus current curve tracer is discussed. The curve tracer employs a capacitive load to provide automatic sweeping of the array voltage. The unit is capable of measuring arrays up to 10 kW, but is similar and lighter than a conventional 2.5-kW dissipative load.
Warner, T.H.; Cox, C.H. III
Saline tracer visualized with three-dimensional electrical resistivity tomography: Field-scale spatial moment analysis
) was used to monitor the migration of a saline tracer in a two-well pumping-injection experiment conducted of the bulk media changes as the tracer migrates from the pumping to the injection well. The local Figure 2 as in (c) a photograph of the site (not aligned to schematics). ERT wells are labeled A-D. Injection
Singha, Kamini
Baroclinic Flow and Transient-Tracer Fields in the Canary�Cape Verde Basin
Simulated transient-tracer distributions (tritium, 3H3, freons) on the isopycnal horizons ?0=26.5 and 26.8 kg m?3 are presented for the East Atlantic, 10� ?40�N. Tracer transport is modeled by employing a baroclinic flow field based on empirical ...
Gerhard Thiele; Wolfgang Roether; Peter Schlosser; Reinhard Kuntz; Gerold Siedler; Lothar Stramma
Feasibility of perfluorocarbon tracers (PFTs) in atmospheric source-receptor experiments
A brief description of the perfluorocarbon tracer (PFT) system, which includes the tracers and the release equipment, the air samplers and the analyzers, is presented along with details on the research needs to provide a viable system for MATEX-scenario experiments. The present family of 2 viable PFTs needs to be increased to 5 to 6. Given the present precision of the analysis system, a one year long tracer experiment consisting of 4 hour releases every 60 hours from 5 different sites would require nearly 150 metric tons of PFTs at a cost of $15,000,000. Shortcomings in the programmable sampler include the pump, the sampling sequence control flexibility, data storage and retrieval, and the lack of remote communication capability; sampler adsorbent studies are also needed. The analytical system, including the catalyst processing bed, the chromatography column resolution, and the linearity of the detector, is in need of significant improvement. A higher resolution analysis system could significantly reduce analysis time but, more importantly, reduce tracer requirements more than 10-fold, for a cost savings potential of more than $13,000,000. A model is presented to demonstrate the feasibility of tracer material balances. Assessment of earlier long-range tracer experiments indicates the need for possibly 400 ground sampling sites requiring $8 to $14 million worth of samplers for a one-year tracer experiment. As many as six aircraft would be needed to conduct airborne model validation and material balance studies for each tracer plume.
Dietz, R.N.; Senum, G.I.
The Advection of High-Resolution Tracers by Low-Resolution Winds
The usefulness of any simulation of atmospheric tracers using low-resolution winds relies on both the dominance of large spatial scales in the strain and time dependence that results in a cascade in tracer scales. Here, a quantitative study on ...
John Methven; Brian Hoskins
Highly enriched multiply-labeled stable isotopic compounds as atmospheric tracers
Compounds multiply-labeled with stable isotopes and highly enriched in these isotopes are readily capable of detection in tracer experiments involving high dilutions. Thus, for example, /sup 13/C/sup 18/O/sub 2/ provides a useful tracer for following atmospheric pol lution produced as a result of fossil fuel burning. (Official Gazette)
Goldblatt, M.; McInteer, B.B.
Rates and Mechanisms of Water Mass Transformation in the Labrador Sea as Inferred from Tracer Observations
Time series of hydrographic and transient tracer (3H and 3He) observations from the central Labrador Sea collected between 1991 and 1996 are presented to document the complex changes in the tracer fields as a result of variations in convective ...
Samar Khatiwala; Peter Schlosser; Martin Visbeck
Tracer Testing At Coso Geothermal Area (2004) | Open Energy Information
Coso Geothermal Area (2004) Coso Geothermal Area (2004) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Tracer Testing Activity Date 2004 Usefulness not indicated DOE-funding Unknown Exploration Basis To determine the EGS potential of the Coso Geothermal Field Notes A dramatic decrease in the ratio of chloride to boron was observed in the liquid discharge of a well proposed for EGS development. The decrease appears to be related to the transformation of some feed zones in the well from liquid-dominated to vapor-dominated. High concentrations of boron are transported to the wellbore in the steam, where it fractionates to the liquid phase flowing in from liquid-dominated feed zones. The high-boron steam is created when the reservoir liquid in some of the feed zones boils
Tracer Testing at Dixie Valley, Nevada, Using 2-Naphthalene Sulfonate and
Tracer Testing at Dixie Valley, Nevada, Using 2-Naphthalene Sulfonate and Tracer Testing at Dixie Valley, Nevada, Using 2-Naphthalene Sulfonate and 2,7-Naphthalene Disulfonate Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Tracer Testing at Dixie Valley, Nevada, Using 2-Naphthalene Sulfonate and 2,7-Naphthalene Disulfonate Abstract The decay kinetics of the candidate tracers 2-naphthalene sulfonate and 2,7-naphthalenedisulfonate was studied under laboratory conditionsthat simulate a hydrothermal environment, withneither compound exhibiting any decay after oneweek at 330�C. These data indicate that thesecompounds are more thermally stable than any of thepreviously studied polyaromatic sulfonates. Both ofthe tracer candidates were successfully tested in afield study at the Dixie Valley, Nevada, geothermalreservoir. In addition to
Enhanced durability and reactivity for zinc ferrite desulfurization sorbent
AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.
Jha, M.C.; Berggren, M.H.
Optimal Allocation of Reactive Power Source in Wind Farms Using Sensitivity Analysis and Tabu Algorithm
Considering wind farms real operation characteristics, a novel method using sensitivity analysis and Tabu algorithm for reactive power compensation allocations is proposed. In this paper, the sensitivity coefficient is defined as partial derivative of ... Keywords: Wind farm, Sensitivity analysis, Reactive power compensation, SVC, Tabu algorithm
Ping Zhang; XiangJun Zeng; Ling Li
Interest in the use of alternative fuels and combustion regimes is increasing as the price of petroleum climbs. The inherently higher efficiency of Diesel engines has led to increased adoption of Diesels in Europe, capturing approximately 40% of the new passenger car market. Unfortunately, lower CO{sub 2} emissions are countered with higher nitrogen oxides (NOx) and particulate matter (PM) emissions, and higher noise. Noise and PM have traditionally been the obstacles toward consumer acceptance of Diesel passenger cars in North America, while NOx (a key component in photochemical smog) has been more of an engineering challenge. Diesels are lean burning (combustion with excess oxygen) and reducing NOx to N2 in an oxygen rich environment is difficult. Adding oxygenated compounds to the fuel helps reduce PM emissions, but relying on fuel alone to reduce PM is unrealistic. Keeping peak combustion temperature below 1700 K prevents NOx formation. Altering the combustion regime to burn at temperatures below the NOx threshold and accept a wide variety of fuels seems like a promising alternative for future engines. Homogeneous Charge Compression Ignition (HCCI) is a possible solution. Fuel and air are well mixed prior to intake into a cylinder (homogeneous charge) and ignition occurs by compression of the fuel-air mixture by the piston. HCCI is rapid and relatively cool, producing little NOx and PM. Unfortunately, it is hard to control since HCCI is initiated by temperature and pressure instead of a spark or direct fuel injection. We investigate biofuel HCCI combustion, and use intrinsically labeled biofuels as tracers of HCCI combustion. Data from tracer experiments are used to validate combustion modeling.
Mack, J H; Flowers, D L; Buchholz, B A; Dibble, R W
Permeable Reactive Barriers | Department of Energy
Permeable Reactive Barriers Permeable Reactive Barriers Permeable Reactive Barriers Permeable Reactive Barrier Field Projects Durango, Colorado DOE installed a PRB in October 1995 to treat ground water from a uranium mill tailings disposal site at Durango, Colorado Read more Cañon City, Colorado ESL personnel conduct tests and help evaluate performance at other PRB sites, such as Cotter Corporation's Cañon City site in Colorado. Read more Monticello, Utah Installation of a PRB hydraulically downgradient of the Monticello, Utah, millsite was completed June 30, 1999, as an Interim Remedial Action. Read more A permeable reactive barrier (PRB) is a zone of reactive material placed underground to intercept and react with a contaminant plume in ground water. Typically, PRBs are emplaced by replacing soils with reactive
Analysis of an interwell tracer test in a depleted heavy oilreservoir
This paper presents field data and analyses of an interwell tracer test conducted in the Niitsu oil field which is a fully depleted heavy oil reservoir of unconsolidated sand formation. The purpose of the tracer test is to diagnose reservoir heterogeneity at a location where a micellar/ polymer field test is planned. Water containing a chemical tracer was injected at a constant rate into an injector surrounded by three production wells. Effluent analyses showed very early breakthrough of injected water at two of the producing wells, no tracer, however, was detected at the third producer thoughout the test period. In addition, tracer production profiles at two wells after breakthrough differed much from each other. These test results suggest a strong areal heterogeneity of the tested formation. An appropriate analytical model was used to obtain a preliminary interpretation of the results. A modified three-dimensional black oil model developed to simulate polymer flood process was then utilized for analyzing the data in more detail. The model treats tracer solution as a fourth component, and can also account for adsorption of tracer.
Ohno, K.; Horne, R.N.; Nanba, T.
Greatly Enhanced Detectability of Geothermal Tracers Through Laser-Induced Fluorescence
WE have successfully completed a four-year R and D project to greatly reduce the detection limit of fluorescent tracers through the use of emerging laser-excitation, optical fiber, and CCD-spectroscopy technologies. Whereas the efforts over the first two years were directed at demonstrating a reduction in the detection limit of fluorescent compounds by a factor of 100 and at identifying several new fluorescein-derived tracer candidates, our recent efforts were focused primarily on the field demonstration of new tracers having detection limits in the low parts-per-quadrillion range. During the summer of 2001, we initiated field tests at the Dixie Valley, Nevada and at the Beowawe, Nevada geothermal fields using very small quantities of the fluorescein-derivative 6-carboxyfluorescein. Subsequently, we succeeded in measuring sub-part-per-trillion quantities of that candidate tracer at both the Beowawe and Dixie Valley geothermal reservoirs-using approximately 530 g of tracer at each setting. Our studies indicate that we could have observed a breakthrough using only 0.53 g of 6-carboxyfluorescein. This represents a reduction by a factor of 170,000 below the mass of tracer used in a previous tracer test at Beowawe.
Peter Rose; Joel Harris; Phaedra Kilbourn; James Kleimeyer; Troy Carter
The NPE gas tracer test and the development of on-site inspection techniques
Tracer gases emplaced in or near the detonation cavity of the 1-kiloton NonProliferation Event required 1.5 and 13.5 months for sulfur hexaflouride and helium-3, respectively, to reach the surface of Rainier Mesa from an emplacement depth of 400 meters. The sites that first produced tracer gases are those located in known faults and fractures. Numerical modeling suggests that transport to the surface is accomplished within this time frame through atmospheric pumping along high permeability pathways such as fractures. The difference in travel time between the two tracers is due to differences in gas diffusivity and can also be explained by our numerical modeling.
Carrigan, C.; Heinle, R.; Zucca, J.J.
Nitrate Removal in NITREXTM Permeable Reactive Barriers
was originally the injection site for our tracer solution, but instead it became our lone up-gradient well) and ~48 hours (low tide) after injection. At every time point, samples were collected from all wells and nitrate concentrations were estimated from samples taken from the injection well right before the solution
Vallino, Joseph J.
Planck cold clumps are among the most promising objects to investigate the initial conditions of the evolution of molecular clouds. In this work, by combing the dust emission data from the survey of the Planck satellite with the molecular data of {sup 12}CO/{sup 13}CO/C{sup 18}O (1-0) lines from observations with the Purple Mountain Observatory 13.7 m telescope, we investigate the CO abundance, CO depletion, and CO-to-H{sub 2} conversion factor of 674 clumps in the early cold cores sample. The median and mean values of the CO abundance are 0.89 Multiplication-Sign 10{sup -4} and 1.28 Multiplication-Sign 10{sup -4}, respectively. The mean and median of CO depletion factor are 1.7 and 0.9, respectively. The median value of X{sub CO-to-H{sub 2}} for the whole sample is 2.8 Multiplication-Sign 10{sup 20} cm{sup -2} K{sup -1} km{sup -1} s. The CO abundance, CO depletion factor, and CO-to-H{sub 2} conversion factor are strongly (anti-)correlated to other physical parameters (e.g., dust temperature, dust emissivity spectral index, column density, volume density, and luminosity-to-mass ratio). To conclude, the gaseous CO abundance can be used as an evolutionary tracer for molecular clouds.
Liu Tie; Wu Yuefang; Zhang Huawei, E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com [Department of Astronomy, Peking University, Beijing 100871 (China)
Alternative High-z Cosmic Tracers and the Dark Energy Equation of State
We propose to use alternative cosmic tracers to measure the dark energy equation of state and the matter content of the Universe [w(z) & \\Omega_m]. Our proposed method consists of two components: (a) tracing the Hubble relation using HII-like starburst galaxies, as an alternative to SNIa, which can be detected up to very large redshifts, z~4, and (b) measuring the clustering pattern of X-ray selected AGN at a median redshift of ~1. Each component of the method can in itself provide interesting constraints on the cosmological parameters, especially under our anticipation that we will reduce the corresponding random and systematic errors significantly. However, by joining their likelihood functions we will be able to put stringent cosmological constraints and break the known degeneracies between the dark energy equation of state (whether it is constant or variable) and the matter content of the universe and provide a powerful and alternative rute to measure the contribution to the global dynamics, and the e...
Plionis, M; Basilakos, S; Bresolin, F; Terlevich, E; Melnick, J; Georgantopoulos, I
Constraining the Dark Energy Equation of State using Alternative High-z Cosmic Tracers
We propose to use alternative cosmic tracers to measure the dark energy equation of state and the matter content of the Universe [w(z) & Omega_m]. Our proposed method consists of two components: (a) tracing the Hubble relation using HII galaxies which can be detected up to very large redshifts, z~4, as an alternative to supernovae type Ia, and (b) measuring the clustering pattern of X-ray selected AGN at a median redshift of z~1. Each component of the method can in itself provide interesting constraints on the cosmological parameters, especially under our anticipation that we will reduce the corresponding random and systematic errors significantly. However, by joining their likelihood functions we will be able to put stringent cosmological constraints and break the known degeneracies between the dark energy equation of state (whether it is constant or variable) and the matter content of the universe and provide a powerful and alternative route to measure the contribution to the global dynamics and the equ...
Plionis, M; Basilakos, S; Bressolin, F; Terlevich, E; Melnick, J; Chavez, R
Identification of the Permeability Field of Porous Medium from the Injection of Passive Tracer
In this paper, a method was proposed which focused on the question, namely on how to invert data on arrival times at various (and numerous) points in the porous medium to map the permeability field. The method, elements of which were briefly described in (9), is based on a direct inversion of the data, as will be described below , rather than on the optimization of initial random (or partly constrained) guesses of the permeability field, to match the available data, as typically done in the analogous problem of pressure transients. The direct inversion is based on two conditions, that Darcy's law for single-phase flow in porous media is valid, and that dispersion of the concentration of the injected tracer is negligible. While the former is a well-accepted premise, the latter depends on injection and field conditions, and may not necessarily apply in all cases. Based on these conditions, we formulate a nonlinear boundary value problem, the coefficients of which depend on the experimental arrival time data.
Zhan, Lang; Yortsos, Y.C.
Rejuvenating Permeable Reactive Barriers by Chemical Flushing
Energy.gov (U.S. Department of Energy (DOE))
Final Report:Rejuvenating Permeable Reactive Barriers by Chemical Flushing,U.S. Environmental Protection Agency, Region 8 Support.August 2004
A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a ...
Electrochemistry of Enargite: Reactivity in Alkaline Solutions
The reactivity of enargite samples from Montana, US and Quiruvilca, Peru were studied under alkaline conditions, pH range of 8-13, using a cyclic voltammetry�...
Reactive Air Aluminizing - Energy Innovation Portal
Reactive Air Aluminizing is a process for applying a protective coating on steel components in solid oxide fuel cells and other high temperature electrochemical devices.
Reactive Air Aluminizing is a process for applying a protective coating on steel components in solid oxide fuel ... Building Energy Efficiency; ...
Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain Site characterization study; Progress report, April 1, 1993--June 30, 1993
This report is in two parts one for the fluorinated benzoic acids and one for the fluorinated aliphatic acids. The assumptions made in the report regarding the amount of tracer that will be used, dilution of the tracer during the test and the length of exposure (if any) to individuals drinking the water were made by the authors. These assumptions must really come from the USGS hydrologists in charge of the c-well tracer testing program. Accurate estimates of dilution of the tracer during the test are also important because of solubility limitations of some of the tracers. Three of the difluorobenzoic acids have relatively low solubilities and may not be usable if the dilution estimates are large. The toxicologist that reviewed the document agreed with our conclusion that the fluorinated benzoic and toluic acids do not represent a health hazard if used under the conditions as outlined in the report. We are currently testing 15 of these compounds, and if even if three difluorobenzoic acids cannot be used because of solubility limitations we will still have 12 tracers. The toxicologist felt that the aliphatic fluorinated acids potentially present more of a health risk than the aromatic. This assessment was based on the fact of a known allergic response to halothane anesthetic. This risk, although minimal, is known and he felt that was enough reason to recommend against their use. The authors feel that the toxicologists interpretation of this risk was overly conservative, however, we will not go against his recommendation at this time for the following reasons. First, without the aliphatic compounds we still have 12 to 15 fluorinated aromatic acids which, should be enough for the c-well tests. Second, to get a permit to use aliphatic compounds would undoubtedly require a hearing which could be quite lengthy.
Dombrowski, T.; Stetzenbach, K.
A Modified Tracer Selection and Tracking Procedure to Derive Winds Using Water Vapor Imagers
The remotely sensed upper-tropospheric water vapor wind information has been of increasing interest for operational meteorology. A new tracer selection based on a local image anomaly and tracking procedure, itself based on Nash�Sutcliffe model ...
S. K. Deb; C. M. Kishtawal; P. K. Pal; P. C. Joshi
Evaluation of Lagrangian Particle Dispersion Models with Measurements from Controlled Tracer Releases
Three widely used Lagrangian Particle Dispersion Models (LPDMs), HYSPLIT, STILT and FLEXPART are evaluated with measurements from the controlled tracer release experiments CAPTEX and ANATEX. The LPDMs are run forward in time driven by identical ...
Jennifer Hegarty; Roland R. Draxler; Ariel F. Stein; Jerome Brioude; Marikate Mountain; Janusz Eluszkiewicz; Thomas Nehrkorn; Fong Ngan; Arlyn Andrews
The Bolus Velocity in the Stochastic Theory of Ocean Turbulent Tracer Transport
A stochastic theory of tracer transport in compressible turbulence has recently been developed and then applied to the ocean case because stratified flow in isopycnal coordinates is analogous to compressible flow with the isopycnal layer ...
John K. Dukowicz; Richard J. Greatbatch
The use of tracers to analyze the effects of reinjection into fractured geothermal reservoirs
This paper discusses the use of tracers as a reservoir engineering tool in fractured geothermal reservoirs. The principle concern in injecting cooler spent fluids into a fractured reservoir is that the fluids may move through high permeability channels and return to the production wells after contacting a relatively small volume of rock. As a consequence of this rapid transport, the fluids will be only partially reheated and after a short period time will effectively mine the heat from the limited volume of rock. The production wells will then experience a rapid and premature reduction in thermal output. Tracers can be used to infer the existence of high mobility conduits between injection and production wells and to monitor chemical changes of an injected fluid. Since tracer arrival precedes thermal breakthrough, tracer tests are a very useful forecasting tool.
Horne, R.N.; Johns, R.A.; Adams, M.C.; Moore, J.N.; Stiger, S.G.
Adjoint-Based Estimation of Eddy-Induced Tracer Mixing Parameters in the Global Ocean
Using the German Estimating the Circulation and Climate of the Ocean (GECCO) synthesis framework, four separate eddy tracer mixing coefficients are adjusted jointly with external forcing fields, such as to reduce a global misfit between the model ...
Chuanyu Liu; Armin K�hl; Detlef Stammer
Sensitivity of the Global Ocean Circulation to Parameterizations of Mesoscale Tracer Transports
The isopycnal transport parameterization of Gent and Mc Williams has been implemented in the GFDL ocean general circulation model, replacing the physically unjustifiable horizontal mixing of tracers. The effects of this parameterization are ...
Gokhan Danabasoglu; James C. Mc Williams
The Influence of Eddies on Tracer Transport in the Abyssal Ocean
Tracer transport mechanisms in a deep western boundary current (DWBC) are explored using a three-layer, eddy-resolving quasigeostrophic model. The model is forced with a steady, sinusoidal wind stress. The effects of the wind stress, coupled with ...
Carol Ladd; Lu Anne Thompson
Transport of a Power Plant Tracer Plume over Grand Canyon National Park
Meteorological and air-quality data, as well as surface tracer concentration values, were collected during 1990 to assess the impacts of Navajo Generating Station (NGS) emissions on Grand Canyon National Park (GCNP) air quality. These data have ...
Jun Chen; Robert Bornstein; Charles G. Lindsey
Interpretation of Measured Tracer Concentration Fluctuations Using a Sinusoidal Meandering Plume Model
Simultaneous instantaneous concentration and wind velocity fluctuations were measured 100 to 752 m downwind of a point source release of SF6 tracer during two field studies conducted amid rolling wheat fields and at a flat desert site in eastern ...
Holly Peterson; Brian Lamb; David Stock
Simulation of Tracer Concentration Data in the Brush Creek Drainage Flow Using an Integrated Puff Model
During the 1984 ASCOT field study in Brush Creek Valley, two perfluorocarbon tracers were released into the nocturnal drainage flow at two different heights. The resulting surface concentrations were sampled at 90 sites, and vertical ...
K. Shankar Rao; Richard M. Eckman; Rayford P. Hosker Jr.
Development of Models to Simulate Tracer Behavior in Enhanced Geothermal Systems
A recent report found that power and heat produced from engineered (or enhanced) geothermal systems (EGSs) could have a major impact on the United States while incurring minimal environmental impacts. EGS resources differ from high-grade hydrothermal resources in that they lack sufficient temperature distributions, permeability/porosity, fluid saturation, or recharge of reservoir fluids. Therefore, quantitative characterization of temperature distributions and the surface area available for heat transfer in EGS is necessary for commercial development of geothermal energy. The goal of this project is to provide integrated tracer and tracer interpretation tools to facilitate this characterization. Modeling capabilities are being developed as part of this project to support laboratory and field testing to characterize engineered geothermal systems in single- and multi-well tests using tracers. The objective of this report is to describe the simulation plan and the status of model development for simulating tracer tests for characterizing EGS.
Williams, Mark D.; Vermeul, Vincent R.; Reimus, P. W.; Newell, D.; Watson, Tom B.
High-Resolution Stratospheric Tracer Fields Reconstructed with Lagrangian Techniques: A Comparative Analysis of Predictive Skill
Numerical experiments and statistical analyses are conducted to determine the skill of different Lagrangian techniques for the construction of tracer distributions. High-resolution potential vorticity (PV) maps are calculated from simulations of ...
R. Dragani; G. Redaelli; G. Visconti; A. Mariotti; V. Rudakov; A. R. MacKenzie; L. Stefanutti
The Adjoint of the Semi-Lagrangian Treatment of the Passive Tracer Equation
A semi-Lagrangian treatment of the 1D passive tracer equation using prescribed piecewise-continuous interpolating functions is considered. Whether the process of localizing the upstream position affects the adjoint counterpart of the associated ...
M. Tanguay; S. Polavarapu
Atmospheric Dispersion from Elevated Sources in an Urban Area: Comparison between Tracer Experiments and Model Calculations
Atmospheric dispersion experiments were carried out in the Copenhagen area under neutral and unstable conditions. The tracer sulphurhexafluoride was released without buoyancy from a tower at a height of 115 m and then collected at ground-level ...
Sven-Erik Gryning; Erik Lyck
Analysis of Tracer Data Collected during the SCCCAMP 1985 Intensive Measurement Periods
This paper contains an analysis of data obtained from measurements of the concentration of tracer gases released during the four intensive measurement periods of the 1985 South-Central Coast Cooperative Air Monitoring Program (SCCCAMP). These ...
David G. Strimaitis; Gary E. Moore; Sharon G. Douglas
Lagrangian Particle Simulation of Tracer Dispersion in the Lee of a Schematic Two-Dimensional Hill
Spray, a 3D Lagrangian particle model for the simulation of complex flow dispersion, is presented. Its performance is tested against the Environmental Protection Agency wind tunnel concentration distribution of passive tracer released from ...
G. Tinarelli; D. Anfossi; G. Brusasca; E. Ferrero; U. Giostra; M. G. Morselli; J. Moussafir; F. Trombetti; F. Tampieri
Tracer Transport in Deep Convective Updrafts: Plume Ensemble versus Bulk Formulations
Two widely used approaches for parameterizing tracer transport based on convective mass fluxes are the plume ensemble formulation (PEF) and the bulk formulation (BF). Here the behavior of these two is contrasted for the specific case in which the ...
Mark G. Lawrence; Philip J. Rasch
Vertical Tracer Concentration Profiles Measured during the Joint Urban 2003 Dispersion Study
An atmospheric tracer dispersion study known as Joint Urban 2003 was conducted in Oklahoma City, Oklahoma, during July of 2003. As part of this field program, vertical concentration profiles were measured at approximately 1 km from the downtown ...
Julia E. Flaherty; Brian Lamb; K. Jerry Allwine; Eugene Allwine
Wintertime Dispersion in a Mountainous Basin at Roanoke, Virginia: Tracer Study
During January 1989, five nighttime SF6 tracer experiments were conducted in Roanoke, Virginia. The experiments were designed to help identify and understand the dispersion characteristics of a basin atmosphere during winter stagnation ...
K. Jerry Allwine; Brian K. Lamb; Robert Eskridge
Use of a Large Crane for Wind and Tracer Profiles in an Urban Setting
Although measured vertical profiles of wind, turbulence, and tracer concentrations are critical for understanding the urban boundary layer, it is problematic to field a sounding system or a tall structure to support anemometers in a densely ...
Frank J. Gouveia; Martin J. Leach; Joseph H. Shinn; William E. Ralph
Eddy Resolution versus Eddy Diffusion in a Double Gyre GCM. Part II: Mixing of Passive Tracers
The parameterization of the effect of the unresolved scales of motion on a passive tracer field in large-scale numerical ocean models is analyzed through a combination of Lagrangian and Eulerian velocities. The primitive equation isopycnal model ...
Horacio A. Figueroa
Dispersion of a Passive Tracer in Buoyancy- and Shear-Driven Boundary Layers
By means of finescale modeling [large-eddy simulation (LES)], the combined effect of thermal and mechanical forcing on the dispersion of a plume in a convective boundary layer is investigated. Dispersion of a passive tracer is studied in various ...
Alessandro Dosio; Jordi Vil�-Guerau de Arellano; Albert A. M. Holtslag; Peter J. H. Builtjes
The Advection�Diffusion Problem for Stratospheric Flow. Part II: Probability Distribution Function of Tracer Gradients
This paper is a continuation of the study of the advection�diffusion problem for stratospheric flow, and deals with the probability distribution function (PDF) of gradients of a freely decaying passive tracer. Theoretical arguments are reviewed ...
Yongyun Hu; Raymond T. Pierrehumbert
Design and Validation of an Offline Oceanic Tracer Transport Model for a Carbon Cycle Study
An offline passive tracer transport model with self-operating diagnostic-mode vertical mixing and horizontal diffusion parameterizations is used with assimilated ocean currents to find the chlorofluorocarbon (CFC-11) cycle in oceans. This model ...
Vinu Valsala; Shamil Maksyutov; Ikeda Motoyoshi
Sensitivity of the Ventilation Process in the North Pacific to Eddy-Induced Tracer Transport
A coarse-resolution isopycnal model coupled with a bulk mixed layer model is used to examine the effect of isopycnal thickness diffusion, which parameterizes the subgrid-scale eddy-induced tracer transport, on ventilation of the North Pacific ...
Takahiro Endoh; Yanli Jia; Kelvin J. Richards
On Ocean Transport Diagnostics: The Idealized Age Tracer and the Age Spectrum
The idealized age tracer is commonly used to diagnose transport in ocean models and to help interpret ocean measurements. In most studies only the steady-state distribution, the result of many centuries of model integration, has been presented ...
Timothy M. Hall; Thomas W. N. Haine
Collection of Water Samples from an Autonomous Underwater Vehicle for Tracer Analysis
A compact water sampler rated to full ocean depth has been deployed from an autonomous underwater vehicle (AUV) to enable oceanographic tracer measurements. Techniques developed to allow the instrument to collect up to 49 samples of sufficient ...
Paul A. Dodd; Martin R. Price; Karen J. Heywood; Miles Pebody
Dynamic Reactive Power Control of Isolated Power Systems
This dissertation presents dynamic reactive power control of isolated power systems. Isolated systems include MicroGrids in islanded mode, shipboard power systems operating offshore, or any other power system operating in islanded mode intentionally or due to a fault. Isolated power systems experience fast transients due to lack of an infinite bus capable of dictating the voltage and frequency reference. This dissertation only focuses on reactive control of islanded MicroGrids and AC/DC shipboard power systems. The problem is tackled using a Model Predictive Control (MPC) method, which uses a simplified model of the system to predict the voltage behavior of the system in future. The MPC method minimizes the voltage deviation of the predicted bus voltage; therefore, it is inherently robust and stable. In other words, this method can easily predict the behavior of the system and take necessary control actions to avoid instability. Further, this method is capable of reaching a smooth voltage profile and rejecting possible disturbances in the system. The studied MicroGrids in this dissertation integrate intermittent distributed energy resources such as wind and solar generators. These non-dispatchable sources add to the uncertainty of the system and make voltage and reactive control more challenging. The model predictive controller uses the capability of these sources and coordinates them dynamically to achieve the voltage goals of the controller. The MPC controller is implemented online in a closed control loop, which means it is self-correcting with the feedback it receives from the system.
Falahi, Milad
Analytic solutions of tracer transport in fractured rock associated with precipitation-dissolution reactions
Precipitation-dissolution reactions are important for a number of applications such as isotopic tracer transport in the subsurface. Analytical solutions have been developed for tracer transport in both single-fracture and multiple-fracture systems associated with these reactions under transient and steady-state transport conditions. These solutions also take into account advective transport in fractures and molecular diffusion in the rock matrix. For studying distributions of disturbed tracer concentration (the difference between actual concentration and its equilibrium value), effects of precipitation-dissolution reactions are mathematically equivalent to a 'decay' process with a decay constant proportional to the corresponding bulk reaction rate. This important feature significantly simplifies the derivation procedure by taking advantage of the existence of analytical solutions for tracer transport associated with radioactive decay in fractured rock. It is also useful for interpreting tracer breakthrough curves, because the impact of a decay process is relatively easy to analyze. Several illustrative examples are presented, which show that the results are sensitive to fracture spacing, matrix diffusion coefficient (fracture surface area), and bulk reaction rate (or 'decay' constant), indicating that the relevant flow and transport parameters may be estimated by analyzing tracer signals.
Liu, H.H.; Mukhopadhyay, S.; Spycher, N.; Kennedy, B.
Analysis of an interwell tracer test in a depleted heavy-oil reservoir
This paper presents field data and analyses of an interwell tracer test conducted in the Niitsu oil field, which is a fully depleted heavy-oil reservoir of unconsolidated sand formation. Water containing a chemical tracer was injected at a constant rate into an injector surrounded by three production wells. Effluent analyses showed very early breakthrough of injected water at two of the producing wells. The test results suggest a strong areal heterogeneity of the tested formation. An appropriate analytic model was used to obtain a preliminary interpretation of the results. A modified three-dimensional (3D) black-oil model developed to simulate th polymer flood process was then used for analyzing the data in more detail. The model treats tracer solution as a fourth component and can also account for adsorption of tracer. Simulation efforts were concentrated on matching the breakthrough times and tracer profiles after breakthrough. Through both the analytic and the simulation work, the reservoir is characterized by a highly heterogeneous distribution of horizontal permeability, a thin layer of high permeability, and a natural waterdrive that cause a preferential flow trend in a direction toward one producer. The authors conclude that the interwell tracer test is an effective tool for evaluating reservoir heterogeneities and a quantitative analysis of test data is done with the polymer option of a black-oil simulator.
Ohno, K.; Nanba, T.; Horne, R.N.
L�vy Fluctuations and Tracer Diffusion in Dilute Suspensions of Algae and Bacteria
Swimming microorganisms rely on effective mixing strategies to achieve efficient nutrient influx. Recent experiments, probing the mixing capability of unicellular biflagellates, revealed that passive tracer particles exhibit anomalous non-Gaussian diffusion when immersed in a dilute suspension of self-motile Chlamydomonas reinhardtii algae. Qualitatively, this observation can be explained by the fact that the algae induce a fluid flow that may occasionally accelerate the colloidal tracers to relatively large velocities. A satisfactory quantitative theory of enhanced mixing in dilute active suspensions, however, is lacking at present. In particular, it is unclear how non-Gaussian signatures in the tracers' position distribution are linked to the self-propulsion mechanism of a microorganism. Here, we develop a systematic theoretical description of anomalous tracer diffusion in active suspensions, based on a simplified tracer-swimmer interaction model that captures the typical distance scaling of a microswimmer's flow field. We show that the experimentally observed non-Gaussian tails are generic and arise due to a combination of truncated L\\'evy statistics for the velocity field and algebraically decaying time correlations in the fluid. Our analytical considerations are illustrated through extensive simulations, implemented on graphics processing units to achieve the large sample sizes required for analyzing the tails of the tracer distributions.
Irwin M. Zaid; J�rn Dunkel; Julia M. Yeomans
Interpretations of Tracer Tests Performed in the Culebra Dolomite at the Waste Isolation Pilot Plant Site
This report provides (1) an overview of all tracer testing conducted in the Culebra Dolomite Member of the Rustler Formation at the Waste Isolation Pilot Plant (WPP) site, (2) a detailed description of the important information about the 1995-96 tracer tests and the current interpretations of the data, and (3) a summary of the knowledge gained to date through tracer testing in the Culebra. Tracer tests have been used to identify transport processes occurring within the Culebra and quantify relevant parameters for use in performance assessment of the WIPP. The data, especially those from the tests performed in 1995-96, provide valuable insight into transport processes within the Culebra. Interpretations of the tracer tests in combination with geologic information, hydraulic-test information, and laboratory studies have resulted in a greatly improved conceptual model of transport processes within the Culebra. At locations where the transmissivity of the Culebra is low ( 4 x 10{sup -6} m{sup 2}/s), we conceptualize the Culebra as a heterogeneous, layered, fractured medium in which advection occurs largely through fractures and solutes diffuse between fractures and matrix at multiple rates. The variations in diffusion rate can be attributed to both variations in fracture spacing (or the spacing of advective pathways) and matrix heterogeneity. Flow and transport appear to be concentrated in the lower Culebra. At all locations, diffusion is the dominant transport process in the portions of the matrix that tracer does not access by flow.
Utility of Bromide and Heat Tracers for Aquifer Characterization Affected by Highly Transient Flow Conditions
A tracer test using both bromide and heat tracers conducted at the Integrated Field Research Challenge site in Hanford 300 Area (300A), Washington, provided an instrument for evaluating the utility of bromide and heat tracers for aquifer characterization. The bromide tracer data were critical to improving the calibration of the flow model complicated by the highly dynamic nature of the flow field. However, most bromide concentrations were obtained from fully screened observation wells, lacking depth-specific resolution for vertical characterization. On the other hand, depth-specific temperature data were relatively simple and inexpensive to acquire. However, temperature-driven fluid density effects influenced heat plume movement. Moreover, the temperature data contained �noise� caused by heating during fluid injection and sampling events. Using the hydraulic conductivity distribution obtained from the calibration of the bromide transport model, the temperature depth profiles and arrival times of temperature peaks simulated by the heat transport model were in reasonable agreement with observations. This suggested that heat can be used as a cost-effective proxy for solute tracers for calibration of the hydraulic conductivity distribution, especially in the vertical direction. However, a heat tracer test must be carefully designed and executed to minimize fluid density effects and sources of noise in temperature data. A sensitivity analysis also revealed that heat transport was most sensitive to hydraulic conductivity and porosity, less sensitive to thermal distribution factor, and least sensitive to thermal dispersion and heat conduction. This indicated that the hydraulic conductivity remains the primary calibration parameter for heat transport.
Ma, Rui; Zheng, Chunmiao; Zachara, John M.; Tonkin, Matthew J.
Urban Dispersion Program MSG05 Field Study: Summary of Tracer and Meteorological Measurements
The Urban Dispersion Program is a multi-year project, funded by the U.S. Department of Homeland Security, to better understand the flow and dispersion of airborne contaminants through and around the deep street canyons of New York City. The first tracer and meteorological field study was a limited study conducted during March 2005 near the Madison Square Garden in midtown Manhattan. Six safe, inert, gaseous perfluorocarbon tracers were released simultaneously at five street-level locations during two experimental days. In addition to collecting tracer data, meteorological data were also collected. Brookhaven National Laboratory conducted the bulk of the tracer and meteorological field efforts with Pacific Northwest National Laboratory and Stevens Institute of Technology assisting by measuring the vertical profile of winds. The Environmental Protection Agency worked with Brookhaven National Laboratory in accomplishing the personal exposure component of the study. This report presents some results from this analysis. In general, different release locations showed vastly different plume footprints for tracer materials, and the situation was made very complex with upwind and/or crosswind transport of tracer near street-level for the different release locations. Overall wind speeds and directions upwind and over the city were generally constant throughout each of the two experimental periods.
Allwine, K Jerry; Flaherty, Julia E.
Tracer test analysis of the Klamath Falls geothermal resource: a comparison of models
Two tracer tests on doublet systems in a fractured geothermal system were carried out in Klamath Falls, Oregon. The purpose of the tests were to obtain data which would lead to information about the reservoir and to test the applicability of current tracer flow models. The results show rapid breakthrough times and indicate fracture flow with vigorous mixing of injector fluid before production of same. This leads to the idea that thermal breakthrough is not directly related to tracer breakthrough in the Klamath Union doublet system. There has been no long-term enthalpy loss from exploiting the resource for 40 years. In order to reduce the data, models were developed to analyze the results. Along with a porous media flow model two mathematical models developed to analyze fractured geothermal systems are used to help decipher the various tracer return curves. The flow of tracers in doublet systems was investigated. A mathematical description is used for tracer flow through fractures as a function of time and various nonlinear parameters which can be found using a curve fitting technique. This allows the reservoir to be qualitatively defined. These models fit the data well, but point to the fact that future improvement needs to be considered for a clearer and more quantitative understanding of fractured geothermal systems. 22 refs., 32 figs., 11 tabs.
Johnson, S.E.
A transport based one-dimensional perturbation code for reactivity calculations in metal systems
A one-dimensional reactivity calculation code is developed using first order perturbation theory. The reactivity equation is based on the multi-group transport equation using the discrete ordinates method for angular dependence. In addition to the first order perturbation approximations, the reactivity code uses only the isotropic scattering data, but cross section libraries with higher order scattering data can still be used with this code. The reactivity code obtains all the flux, cross section, and geometry data from the standard interface files created by ONEDANT, a discrete ordinates transport code. Comparisons between calculated and experimental reactivities were done with the central reactivity worth data for Lady Godiva, a bare uranium metal assembly. Good agreement is found for isotopes that do not violate the assumptions in the first order approximation. In general for cases where there are large discrepancies, the discretized cross section data is not accurately representing certain resonance regions that coincide with dominant flux groups in the Godiva assembly. Comparing reactivities calculated with first order perturbation theory and a straight {Delta}k/k calculation shows agreement within 10% indicating the perturbation of the calculated fluxes is small enough for first order perturbation theory to be applicable in the modeled system. Computation time comparisons between reactivities calculated with first order perturbation theory and straight {Delta}k/k calculations indicate considerable time can be saved performing a calculation with a perturbation code particularly as the complexity of the modeled problems increase.
Wenz, T.R.
Reactive Power Management to Address Short-Term Voltage Stability Using Optimal Reactive Power Allocation Method
Voltage stability has attracted attention recently because power systems are increasingly operated under heavy loads and subjected to high levels of dynamic fast acting loads. Voltage instability under these conditions can be manifested as depressed voltage profiles, delayed voltage recovery at load buses following a major disturbance, and even fast voltage collapse. Single-phase, low-inertia induction motors can have adverse effect on voltage stability as they decelerate in the event of voltage ...
Geometric Offsets Across Spiral Arms in M51: Nature of Gas and Star Formation Tracers
We report measurements of geometric offsets between gas spiral arms and associated star forming regions in the grand-design spiral galaxy M51. These offsets are a suggested measure of the star formation timescale after the compression of gas at spiral arm entry. A surprising discrepancy, by an order of magnitude, has been reported in recent offset measurements in nearby spiral galaxies. Measurements using CO and H-alpha emission find large and ordered offsets in M51. On the contrary, small or non-ordered offsets have been found using the HI 21cm and 24 micron emissions, possible evidence against gas flow through spiral arms, and thus against the conventional density-wave theory with a stationary spiral pattern. The goal of this paper is to understand the cause of this discrepancy. We investigate potential causes by repeating those previous measurements using equivalent data, methods, and parameters. We find offsets consistent with the previous measurements and conclude that the difference of gas tracers, i.e....
Louie, M; Egusa, F
AMAX Research Development Center (AMAX R D) investigated methods for enhancing the reactivity and durability of zinc ferrite desulfurization sorbents. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For this program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such as size, strength, and specific surface area during 10 cycles of sulfidation and oxidation. Two base case sorbents, a spherical pellet and a cylindrical extrude used in related METC-sponsored projects, were used to provide a basis for the aimed enhancement in durability and reactivity. Sorbent performance was judged on the basis of physical properties, single particle kinetic studies based on thermogravimetric (TGA) techniques, and multicycle bench-scale testing of sorbents. A sorbent grading system was utilized to quantify the characteristics of the new sorbents prepared during the program. Significant enhancements in both reactivity and durability were achieved for the spherical pellet shape over the base case formulation. Overall improvements to reactivity and durability were also made to the cylindrical extrude shape. The primary variables which were investigated during the program included iron oxide type, zinc oxide:iron oxide ratio, inorganic binder concentration, organic binder concentration, and induration conditions. The effects of some variables were small or inconclusive. Based on TGA studies and bench-scale tests, induration conditions were found to be very significant.
Berggren, M.H.; Jha, M.C.
Simulations of highly reactive fluids
We report density functional molecular dynamics simulations to determine the early chemical events of hot (T = 3000 K) and dense (1.97 g/cm{sup 3}, V/V{sub 0} = 0.68) nitromethane (CH{sub 3}NO{sub 2}). The first step in the decomposition process is an intermolecular proton abstraction mechanism that leads to the formation of CH{sub 3}NO{sub 2}H and the aci ion H{sub 2}CNO{sub 2}{sup -}, in support of evidence from static high-pressure and shock experiments. An intramolecular hydrogen transfer that transforms nitromethane into the aci acid form, CH{sub 2}NO{sub 2}H, accompanies this event. This is the first confirmation of chemical reactivity with bond selectivity for an energetic material near the condition of fully reacted specimen. We also report the decomposition mechanism followed up to the formation of H{sub 2}O as the first stable product.
Fried, L E; Manaa, M R; Reed, E J
Reactive Power Measurement Using the Wavelet Transform
Abstract�This paper provides the theoretical basis for the measurement of reactive and distortion powers from the wavelet transforms. The measurement of reactive power relies on the use of broad-band phase-shift networks to create concurrent in-phase currents and quadrature voltages. The wavelet real power computation resulting from these 90 phase-shift networks yields the reactive power associated with each wavelet frequency level or subband. The distortion power at each wavelet subband is then derived from the real, reactive and apparent powers of the subband, where the apparent power is the product of the v; i element pair's subband rms voltage and current. The advantage of viewing the real and reactive powers in the wavelet domain is that the domain preserves both the frequency and time relationship of these powers. In addition, the reactive power associated with each wavelet subband is a signed quantity and thus has a direction associated with it. This permits tracking the reactive power flow in each subband through the power system. Index Terms�Digital signal processing, phase shift networks, measurement, power, RMS, subband, wavelets. I.
Weon-ki Yoon; Michael J. Devaney
Comparison of biomass and coal char reactivities
Char combustion is typically the rate limiting step during the combustion of solid fuels. The magnitude and variation of char reactivity during combustion are, therefore, of primary concern when comparing solid fuels such as coal and biomass. In an effort to evaluate biomass` potential as a sustainable and renewable energy source, the reactivities of both biomass and coal chars were compared using Sandia`s Captive Particle Imaging (CPI) apparatus. This paper summarizes the experimental approach used to determine biomass and coal reactivities and presents results from CPT experiments. The reactivity of six types of char particles, two high-rank coal chars, two low-rank coal chars, and two biomass chars, were investigated using the CPT apparatus. Results indicate that both of the high-rank coal chars have relatively low reactivities when compared with the higher reactivities measured for the low-rank coal and the biomass chars. In addition, extinction behavior of the chars support related investigations that suggest carbonaceous structural ordering is an important consideration in understanding particle reactivity as a function of extent of burnout. High-rank coal chars were found to have highly ordered carbon structures, where as, both low-rank coal and biomass chars were found to have highly disordered carbon structures.
Huey, S.P. [Sandia National Labs., Livermore, CA (United States); Davis, K.A. [Reaction Engineering International, Salt Lake City, UT (United States); Hurt, R.H. [Brown Univ., Providence, RI (United States). Div. of Engineering
Improved generation of large-scale atomistic representations and pyrolysis/combustion simulations of Illinois coal and coal char using the Reaxff reactive force field.
??A highly automated molecular generation approach was implemented and coupled with reactive force field methods to create a new computational capability that enabled the investigation� (more)
Castro Marcano, Fidel
Analysis of Reactivity Induced Accident for Control Rods Ejection with Loss of Cooling
Understanding of the time-dependent behavior of the neutron population in nuclear reactor in response to either a planned or unplanned change in the reactor conditions, is a great importance to the safe and reliable operation of the reactor. In the present work, the point kinetics equations are solved numerically using stiffness confinement method (SCM). The solution is applied to the kinetics equations in the presence of different types of reactivities and is compared with different analytical solutions. This method is also used to analyze reactivity induced accidents in two reactors. The first reactor is fueled by uranium and the second is fueled by plutonium. This analysis presents the effect of negative temperature feedback with the addition positive reactivity of control rods to overcome the occurrence of control rod ejection accident and damaging of the reactor. Both power and temperature pulse following the reactivity- initiated accidents are calculated. The results are compared with previous works and...
Saad, Hend Mohammed El Sayed; Wahab, Moustafa Aziz Abd El
Understanding of the time-dependent behavior of the neutron population in nuclear reactor in response to either a planned or unplanned change in the reactor conditions, is a great importance to the safe and reliable operation of the reactor. In the present work, the point kinetics equations are solved numerically using stiffness confinement method (SCM). The solution is applied to the kinetics equations in the presence of different types of reactivities and is compared with different analytical solutions. This method is also used to analyze reactivity induced accidents in two reactors. The first reactor is fueled by uranium and the second is fueled by plutonium. This analysis presents the effect of negative temperature feedback with the addition positive reactivity of control rods to overcome the occurrence of control rod ejection accident and damaging of the reactor. Both power and temperature pulse following the reactivity- initiated accidents are calculated. The results are compared with previous works and satisfactory agreement is found.
Hend Mohammed El Sayed Saad; Hesham Mohammed Mohammed Mansour; Moustafa Aziz Abd El Wahab
Union Fenosa's La Robla I Power Station is a 270-MW Foster Wheeler arch-fired system. The unit is located at the mine that provides a portion of the semianthracitic coal. The remaining coals used are from South Africa, Russia, Australia, and China. The challenges at the La Robla I Station stem from the various fuels used, the characteristics of which differ from the design coal. The University of North Dakota Energy & Environmental Research Center (EERC) and the Lehigh University Energy Research Center (LUERC) undertook a program to assess problematic slagging and unburned carbon issues occurring at the plant. Full-scale combustion tests were performed under baseline conditions, with elevated oxygen level and with redistribution of air during a site visit at the plant. During these tests, operating information, observations and temperature measurements, and coal, slag deposit, and fly ash samples were obtained to assess slagging and unburned carbon. The slagging in almost all cases appeared due to elevated temperatures rather than fuel chemistry. The most severe slagging occurred when the temperature at the sampling port was in excess of 1500 C, with problematic slagging where first-observed temperatures exceeded 1350 C. The presence of anorthite crystals in the bulk of the deposits analyzed indicates that the temperatures were in excess of 1350 C, consistent with temperature measurements during the sampling period. Elevated temperatures and ''hot spots'' are probably the result of poor mill performance, and a poor distribution of the coal from the mills to the specific burners causes elevated temperatures in the regions where the slag samples were extracted. A contributing cause appeared to be poor combustion air mixing and heating, resulting in oxygen stratification and increased temperatures in certain areas. Air preheater plugging was observed and reduces the temperature of the air in the windbox, which leads to poor combustion conditions, resulting in unburned carbon as well as slagging. A second phase of the project involved advanced analysis of the baseline coal along with an Australian coal fired at the plant. These analysis results were used in equilibrium thermodynamic modeling along with a coal quality model developed by the EERC to assess slagging, fouling, and opacity for the coals. Bench-scale carbon conversion testing was performed in a drop-tube furnace to assess the reactivity of the coals. The Australian coal had a higher mineral content with significantly more clay minerals present than the baseline coal. The presence of these clay minerals, which tend to melt at relatively low temperatures, indicated a higher potential for problematic slagging than the baseline coal. However, the pyritic minerals, comprising over 25% of the baseline mineral content, may form sticky iron sulfides, leading to severe slagging in the burner region if local areas with reducing conditions exist. Modeling results indicated that neither would present significant fouling problems. The Australian coal was expected to show slagging behavior much more severe than the baseline coal except at very high furnace temperatures. However, the baseline coal was predicted to exhibit opacity problems, as well as have a higher potential for problematic calcium sulfate-based low-temperature fouling. The baseline coal had a somewhat higher reactivity than the Australian coal, which was consistent with both the lower average activation energy for the baseline coal and the greater carbon conversion at a given temperature and residence time. The activation energy of the baseline coal showed some effect of oxygen on the activation energy, with E{sub a} increasing at the lower oxygen concentration, but may be due to the scatter in the baseline coal kinetic values at the higher oxygen level tested.
Donald P. McCollor; Kurt E. Eylands; Jason D. Laumb
Laboratory testing and modeling to evaluate perfluorocarbon compounds as tracers in geothermal systems
The thermal stability and adsorption characteristics of three perfluorinated hydrocarbon compounds were evaluated under geothermal conditions to determine the potential to use these compounds as conservative or thermally-degrading tracers in Engineered (or Enhanced) Geothermal Systems (EGS). The three compounds tested were perfluorodimethyl-cyclobutane (PDCB), perfluoromethylcyclohexane (PMCH), and perfluorotrimethylcyclohexane (PTCH), which are collectively referred to as perfluorinated tracers, or PFTs. Two sets of duplicate tests were conducted in batch mode in gold-bag reactors, with one pair of reactors charged with a synthetic geothermal brine containing the PFTs and a second pair was charged with the brine-PFT mixture plus a mineral assemblage chosen to be representative of activated fractures in an EGS reservoir. A fifth reactor was charged with deionized water containing the three PFTs. The experiments were conducted at {approx}100 bar, with temperatures ranging from 230 C to 300 C. Semi-analytical and numerical modeling was also conducted to show how the PFTs could be used in conjunction with other tracers to interrogate surface area to volume ratios and temperature profiles in EGS reservoirs. Both single-well and cross-hole tracer tests are simulated to illustrate how different suites of tracers could be used to accomplish these objectives. The single-well tests are especially attractive for EGS applications because they allow the effectiveness of a stimulation to be evaluated without drilling a second well.
Reimus, Paul W [Los Alamos National Laboratory
Lidar Sensing of Plume Dispersion: Analysis Methods and Product Quality for Light-Scattering Tracer Particles
Analysis procedures are described for retrieving accurate plume information from lidar data on light-scattering particles during atmospheric dispersion experiments. Interactive computer graphics aided in the solution of the lidar equation for ...
W. L. Eberhard; G. T. McNice; S. W. Troxel
A radiocarbon method and multi-tracer approach to quantifying groundwater discharge to coastal waters
Groundwater discharge into estuaries and the coastal ocean is an important mechanism for the transport of dissolved chemical species to coastal waters. Because many dissolved species are present in groundwater in concentrations ...
Gramling, Carolyn M
Identification of Critical Voltage Control Areas and Determination of Required Reactive Power Reserves
The objective of this research project is to investigate and devise a methodology for identifying areas in power systems that are prone to voltage instability under particular operating conditions and contingencies. These areas, which are prone to instability due to their lack of reactive power reserves, are referred to as critical voltage control areas (VCAs). Once VCAs are identified, methods of determining their adequate reactive power reserve requirements to ensure secure system operation under all c...
GE Energy Coupled Microgirid Project -University of Notre Dame -April 7, 2011 Distributive Reactive Control in Coupled Microgrids
Reactive Control in Coupled Microgrids Task Objectives and Approach simPower Model of MV Network CERTS Microgrid Models Reactive Control of Voltage Rise Deliverables Schedule Distributed Event-Triggered Control of Coupled Microgrids #12;Task Objectives and Approach Task will develop distributed methods to maximize
Lemmon, Michael
Final Report Phase II: Performance Evaluation of Permeable Reactive
Final Report Phase II: Performance Evaluation of Permeable Reactive Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing More Documents & Publications Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Rejuvenating Permeable Reactive Barriers by Chemical Flushing Final Report - Rejuvenating Permeable Reactive Barriers by Chemical
Hydraulic Conductivity of the Monticello Permeable Reactive Barrier
Hydraulic Conductivity of the Monticello Permeable Reactive Barrier Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update More Documents & Publications Variation in Hydraulic Conductivity Over Time at the Monticello Permeable Reactive Barrier Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium Mill Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium
Efficient and Reliable Reactive Power Supply and Consumption...
Efficient and Reliable Reactive Power Supply and Consumption - Insights from an Integrated Program of Engineering and Economics Research Title Efficient and Reliable Reactive Power...
Olefin production via reactive distillation based Olefin metathesis.
??Reactive distillation is a combination of a traditional multi-stage distillation column with a chemical reaction. The primary benefits of a reactive distillation process are reduced� (more)
Morrison, Ryan Frederick
A Parametric Reactive Distillation Study: Economic Feasibility and Design Heuristics.
??The integration of reaction and distillation into a single column is called reactive distillation or catalytic distillation. Reactive distillation provides many benefits such as reduced� (more)
Hoyme, Craig Alan
Observations on the Coke Air Reactivity Test - Programmaster.org
Coke air reactivities are strongly dependent on coke calcination levels and it is possible to drive air reactivities lower by increasing calcining temperatures.
Heat as a Tracer to Examine Hydraulic Conductance Near the Russian River Bank Filtration Facility, Sonoma County, CA
to examine streambed hydraulic conductance near the Russianas a tracer to determine the hydraulic conductance of themodel requires that key hydraulic parameters be identified,
Constantz, Jim; Su, Grace; Hatch, Christine
Reactive Air Brazing: A Novel Method of Sealing SOFCs and ...
We demonstrate that the seal is hermetic and resistant to thermal aging, can be thermally cycled under rapid heating rates with no measurable loss in ...
Reactive Air Brazing: Method of Joining Ceramic and Metal ...
Computers & Electronics; Consumer Products; Energy & Utilities; Manufacturing & Warehousing; Publication(s) Brazing as a means of sealing ...
A method of reactive zoom control from uncertainty in tracking
The tuning of a constant velocity Kalman filter, used for tracking by a camera fitted with a variable focal-length lens, is shown to be preserved under a scale change in process noise if accompanied by an inverse scaling in the focal length, provided ... Keywords: Active vision, Visual tracking, Zoom control
B. J. Tordoff; D. W. Murray
Reactive multilayer synthesis of hard ceramic foils and films
Disclosed is method for synthesizing hard ceramic materials such as carbides, borides and aluminides, particularly in the form of coatings provided on another material so as to improve the wear and abrasion performance of machine tools, for example. Method involves the sputter deposition of alternating layers of reactive metals with layers of carbon, boron, or aluminum and the subsequent reaction of the multilayered structure to produce a dense crystalline ceramic. The material can be coated on a substrate or formed as a foil which can be coiled as a tape for later use.
Makowiecki, D.M.; Holt, J.B.
Reactivity control assembly for nuclear reactor
Reactivity control assembly for nuclear reactor comprises supports stacked above reactor core for holding control rods. Couplers associated with the supports and a vertically movable drive shaft have lugs at their lower ends for engagement with the supports.
Bollinger, Lawrence R. (Schenectady, NY)
A Tariff for Reactive Power - IEEE
This paper describes a suggested tariff or payment for the local supply of reactive power from distributed energy resources. The authors consider four sample customers, and estimate the cost of supply of reactive power for each customer. The power system savings from the local supply of reactive power are also estimated for a hypothetical circuit. It is found that reactive power for local voltage regulation could be supplied to the distribution system economically by customers when new inverters are installed. The inverter would be supplied with a power factor of 0.8, and would be capable of local voltage regulation to a schedule supplied by the utility. Inverters are now installed with photovoltaic systems, fuel cells and microturbines, and adjustable-speed motor drives.
Kueck, John D [ORNL; Tufon, Christopher [Pacific Gas and Electric Company; Isemonger, Alan [California Independent System Operator; Kirby, Brendan J [ORNL
Mild coal pretreatment to improve liquefaction reactivity
This report describes work completed during the fourth quarter of a three year project to study the effects of mild chemical pretreatment on coal dissolution reactivity during low severity liquefaction or coal/oil coprocessing. The overall objective of this research is to elucidate changes in the chemical and physical structure of coal by pretreating with methanol or other simple organic solvent and a trace amount of hydrochloric acid and measure the influence of these changes on coal dissolution reactivity. This work is part of a larger effort to develop a new coal liquefaction or coal/oil coprocessing scheme consisting of three main process steps: (1) mile pretreatment of the feed coal to enhance dissolution reactivity and dry the coal, (2) low severity thermal dissolution of the pretreated coal to obtain a very reactive coal-derived residual material amenable to upgrading, and (3) catalytic upgrading of the residual products to distillate liquids.
Miller, R.L.
Fossil plant layup and reactivation conference: Proceedings
The Fossil Plant Layup and Reactivation Conference was held in New Orleans, Louisiana on April 14--15, 1992. The Conference was sponsored by EPRI and hosted by Entergy Services, Inc. to bring together representatives from utilities, consulting firms, manufacturers and architectural engineers. Eighteen papers were presented in three sessions. These sessions were devoted to layup procedures and practices, and reactivation case studies. A panel discussion was held on the second day to interactively discuss layup and reactivation issues. More than 80 people attended the Conference. This report contains technical papers and a summary of the panel discussion. Of the eighteen papers, three are related to general, one is related to regulatory issues, three are related to specific equipment, four are related to layup procedures and practices, and seven are layup and reactivation case studies.
Oxidation Resistance of Reactive Atoms in Graphene
We have found that reactive elements that are normally oxidized at room temperature are present as individual atoms or clusters on and in graphene. Oxygen is present in these samples but it is only detected in the thicker amorphous carbon layers present in the graphene specimens we have examined. However, we have seen no evidence that oxygen reacts with the impurity atoms and small clusters of these normally reactive elements when they are incorporated in the graphene layers. First principles calculations suggest that the oxidation resistance is due to kinetic effects such as preferential bonding of oxygen to nonincorporated atoms and H passivation. The observed oxidation resistance of reactive atoms in graphene may allow the use of these incorporated metals in catalytic applications. It also opens the possibility of designing and producing electronic, opto-electronic, and magnetic devices based on these normally reactive atoms.
Chisholm, Matthew F [ORNL; Duscher, Gerd [University of Tennessee, Knoxville (UTK); Windl, Wolfgang [Ohio State University
Radiative Forcing Due to Reactive Gas Emissions
Reactive gas emissions (CO, NOx, VOC) have indirect radiative forcing effects through their influences on tropospheric ozone and on the lifetimes of methane and hydrogenated halocarbons. These effects are quantified here for the full set of ...
T. M. L. Wigley; S. J. Smith; M. J. Prather
NATURALLY-OCCURRING TRACERS TO MONITOR TWO-PHASE CONDITIONS IN THE NATURALLY-OCCURRING TRACERS TO MONITOR TWO-PHASE CONDITIONS IN THE COSO EGS PROJECT Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: USE OF NATURALLY-OCCURRING TRACERS TO MONITOR TWO-PHASE CONDITIONS IN THE COSO EGS PROJECT Details Activities (1) Areas (1) Regions (0) Abstract: A dramatic decrease in the ratio of chloride to boron was observed in the liquid discharge of a well proposed for EGS development in the Coso geothermal field. The decrease appears to be related to the transformation of some feed zones in the well from liquid-dominated to vapor-dominated. High concentrations of boron are transported to the wellbore in the steam, where it fractionates to the liquid phase flowing in from liquid-dominated feed zones. The high-boron steam is created when the
The use of air as a natural tracer infractured hydrothermal systems, Los Azufres, Mexico, case study
Injection of atmospheric air mixed with cold water has been occurring since 1982 at the Los Azufres geothermal field. Several chemical and thermodynamical evidences show that air injection into this fractured hydrothermal system could be considered as a long term natural tracer test. Nitrogen and Argon separated from the air mixture migrate, under the action of the induced injection-extraction gradient, from reinjection sectors to production zones following preferential paths closely related to high permeability conduits. A coarse numerical estimation of the average permeability tensor existing at Tejamaniles, the southern sector, explains the unsuccessful recovery of the artificial tracer tests performed in past years: the anisotropic nature of the fractured volcanic rock would demand considerably quantities of tracer in order to be detected at the producing wells, especially when fluid extraction was low. At the same time concentrations of calcium, cesium, chloride, potassium, rubidium and sodium, are increasing in the liquid produced by the oldest wells of this field's sector.
Mario Cesar Sudrez Arriaga; Hector Gutierrez Puente, Josefina Moreno Ochoa
Kinetics of fluorescein decay and its application as a geothermal tracer
This paper reports on fluorescent which is a dye used to trace the path of injected fluids through geothermal reservoirs. The authors have measured its thermal stability at temperatures up to 300{degrees} C in hydrothermal autoclaves at various fluid compositions, pHs, and oxygen concentrations. The results of these experiments indicate that fluorescein will decay less than 10% during a one month tracer test in geothermal reservoirs with temperatures below 210{degrees} C. For tracer test involving longer times and/or higher temperatures, the activation parameters presented in this study can be used to correct for thermal decay. These parameters were applied to a tracer test conducted at the Dixie Valley, Nevada geothermal system to correct for the thermal decay of fluorescein and to deduce the effective temperature of the injection-production flow path.
Adams, M.C.; Davis, J. (Univ. of Utah Research Inst., Salt Lake City, UT (US))
Enhanced Oxidative Reactivity for Anthracite Coal via a Reactive Ball Milling Pretreatment Step
Reactive ball milling in a cyclohexene solvent significantly increases the oxidative reactivity of an anthracite coal, due to the combined effects of particle size reduction, metal introduction, introduction of volatile matter, and changes in carbon structure. Metals introduced during milling can be easily removed via a subsequent demineralization process, and the increased reactivity is retained. Solvent addition alters the morphological changes that occur during pyrolysis and leads to a char with significantly increased reactivity. When the solvent is omitted, similar effects are seen for the milled product, but a significant fraction of the char is resistant to oxidation. 33 refs., 3 figs., 1 tab.
Angela D. Lueking; Apurba Sakti; Dania Alvarez-Fonseca; Nichole Wonderling [Pennsylvania State University, PA (United States). Department of Energy and Mineral Engineering
This report provides (1) an overview of all tracer testing conducted in the Culebra Dolomite Member of the Rustler Formation at the Waste Isolation Pilot Plant (WPP) site, (2) a detailed description of the important information about the 1995-96 tracer tests and the current interpretations of the data, and (3) a summary of the knowledge gained to date through tracer testing in the Culebra. Tracer tests have been used to identify transport processes occurring within the Culebra and quantify relevant parameters for use in performance assessment of the WIPP. The data, especially those from the tests performed in 1995-96, provide valuable insight into transport processes within the Culebra. Interpretations of the tracer tests in combination with geologic information, hydraulic-test information, and laboratory studies have resulted in a greatly improved conceptual model of transport processes within the Culebra. At locations where the transmissivity of the Culebra is low (< 4 x 10{sup -6} m{sup 2}/s), we conceptualize the Culebra as a single-porosity medium in which advection occurs largely through the primary porosity of the dolomite matrix. At locations where the transmissivity of the Culebra is high (> 4 x 10{sup -6} m{sup 2}/s), we conceptualize the Culebra as a heterogeneous, layered, fractured medium in which advection occurs largely through fractures and solutes diffuse between fractures and matrix at multiple rates. The variations in diffusion rate can be attributed to both variations in fracture spacing (or the spacing of advective pathways) and matrix heterogeneity. Flow and transport appear to be concentrated in the lower Culebra. At all locations, diffusion is the dominant transport process in the portions of the matrix that tracer does not access by flow.
Reactive Distillation for Esterification of Bio-based Organic Acids
The following is the final report of the three year research program to convert organic acids to their ethyl esters using reactive distillation. This report details the complete technical activities of research completed at Michigan State University for the period of October 1, 2003 to September 30, 2006, covering both reactive distillation research and development and the underlying thermodynamic and kinetic data required for successful and rigorous design of reactive distillation esterification processes. Specifically, this project has led to the development of economical, technically viable processes for ethyl lactate, triethyl citrate and diethyl succinate production, and on a larger scale has added to the overall body of knowledge on applying fermentation based organic acids as platform chemicals in the emerging biorefinery. Organic acid esters constitute an attractive class of biorenewable chemicals that are made from corn or other renewable biomass carbohydrate feedstocks and replace analogous petroleum-based compounds, thus lessening U.S. dependence on foreign petroleum and enhancing overall biorefinery viability through production of value-added chemicals in parallel with biofuels production. Further, many of these ester products are candidates for fuel (particularly biodiesel) components, and thus will serve dual roles as both industrial chemicals and fuel enhancers in the emerging bioeconomy. The technical report from MSU is organized around the ethyl esters of four important biorenewables-based acids: lactic acid, citric acid, succinic acid, and propionic acid. Literature background on esterification and reactive distillation has been provided in Section One. Work on lactic acid is covered in Sections Two through Five, citric acid esterification in Sections Six and Seven, succinic acid in Section Eight, and propionic acid in Section Nine. Section Ten covers modeling of ester and organic acid vapor pressure properties using the SPEAD (Step Potential Equilibrium and Dynamics) method.
Fields, Nathan; Miller, Dennis J.; Asthana, Navinchandra S.; Kolah, Aspi K.; Vu, Dung; Lira, Carl T.
review of extraction, processing, properties & applications of reactive ...
REVIEW OF EXTRACTION,. PROCESSING, PROPERTIES. & APPLICATIONS OF. REACTIVE METALS. Edited by. Brajendra Mishra�...
The Dispersion of Tracer Plumes in Mountainous Regions in Central Arizona: Comparisons between Observations and Modeling Results
A three-dimensional, time-dependent, nested-grid model is used to calculate the targeting of tracer or Seeding material over complex terrain in northern Arizona. Good agreement with measurements of SF6 tracer is reported in three case studies. ...
Roelof T. Bruintjes; Terry L. Clark; William D. Hall
Tracer Conservation for Three-Dimensional, Finite-Element, Free-Surface, Ocean Modeling on Moving Prismatic Meshes
Large-scale free-surface ocean models designed to run over climatic time scales are required to globally conserve the volume and any tracer up to machine precision. In addition, local consistency is critical and requires that the discrete tracer ...
Laurent White; Vincent Legat; Eric Deleersnijder
Southeast Geyers Cooperative Tracer Evaluation and Testing Program for the Purpose of Estimating The Efficiency of Injection
The Southeast Geysers Cooperative Tracer Evaluation Program has been a joint project located in the SE part of the Geysers geothermal field, in Lake and Sonoma Counties, California. A new generation of environmentally benign vapor-phase tracers has been used to estimate the varying degrees to which injectate is being recovered following the significant increase of injected volumes within the Southeast Geysers.
J.L. (Bill) Smith
Phase II: Performance Evaluation of Permeable Reactive Barriers and
Phase II: Performance Evaluation of Permeable Reactive Barriers and Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing U. S. Environmental Protection Agency Region 8 Support January 2004 Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing More Documents & Publications Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Rejuvenating Permeable Reactive Barriers by Chemical Flushing
Hydraulic Conductivity of the Monticello Permeable Reactive Barrier Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update More Documents & Publications Variation in Hydraulic Conductivity Over Time at the Monticello Permeable Reactive Barrier Ground-Water Table and Chemical Changes in an Alluvial Aquifer During Sustained Pumping at the Monticello, Utah, Zero-Valent Iron Treatment Cells Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium
Final Report Phase II: Performance Evaluation of Permeable Reactive Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing More Documents & Publications Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report - Rejuvenating Permeable Reactive Barriers by Chemical Flushing, U.S. Environmental Protection Agency Region 8 Support
Transport Modeling of Reactive and Non-Reactive Constituents from Summitville,
Survey (USGS) began water- quality investigations at Summitville, Terrace #12;Figure 2. Aerial photographTransport Modeling of Reactive and Non- Reactive Constituents from Summitville, Colorado in the Wightman Fork/Alamosa River system downstream of the Summitville Mine, south-central Colorado, were
Hydrological parameter estimations from a conservative tracer test with variable-density effects at the Boise Hydrogeophysical Research Site
Reliable predictions of groundwater flow and solute transport require an estimation of the detailed distribution of the parameters (e.g., hydraulic conductivity, effective porosity) controlling these processes. However, such parameters are difficult to estimate because of the inaccessibility and complexity of the subsurface. In this regard, developments in parameter estimation techniques and investigations of field experiments are still challenging and necessary to improve our understanding and the prediction of hydrological processes. Here we analyze a conservative tracer test conducted at the Boise Hydrogeophysical Research Site in 2001 in a heterogeneous unconfined fluvial aquifer. Some relevant characteristics of this test include: variable-density (sinking) effects because of the injection concentration of the bromide tracer, the relatively small size of the experiment, and the availability of various sources of geophysical and hydrological information. The information contained in this experiment is evaluated through several parameter estimation approaches, including a grid-search-based strategy, stochastic simulation of hydrological property distributions, and deterministic inversion using regularization and pilot-point techniques. Doing this allows us to investigate hydraulic conductivity and effective porosity distributions and to compare the effects of assumptions from several methods and parameterizations. Our results provide new insights into the understanding of variabledensity transport processes and the hydrological relevance of incorporating various sources of information in parameter estimation approaches. Among others, the variable-density effect and the effective porosity distribution, as well as their coupling with the hydraulic conductivity structure, are seen to be significant in the transport process. The results also show that assumed prior information can strongly influence the estimated distributions of hydrological properties.
Dafflon, Baptisite; Barrash, Warren; Cardiff, Michael A.; Johnson, Timothy C.
Generalized chloride mass balance: Forward and inverse solutions for one-dimensional tracer convection under transient flux
Forward and inverse solutions are provided for analysis of inert tracer profiles resulting from one-dimensional convective transport under fluxes which vary with time and space separately. The developments are displayed as an extension of conventional chloride mass balance (CMB) techniques to account for transient as well as space-dependent water fluxes. The conventional chloride mass balance has been used over two decades to estimate recharge over large time scales in arid environments. In this mass balance approach, the chloride concentration in the pore water, originating from atmospheric fallout, is inversely proportional to the flux of water through the sediments. The CMB method is especially applicable to arid and semi-arid regions where evapotranspirative enrichment of the pore water produces a distinct chloride profile in the unsaturated zone. The solutions presented allow incorporation of transient fluxes and boundary conditions in CMB analysis, and allow analysis of tracer profile data which is not constant with depth below extraction zone in terms of a rational water transport model. A closed-form inverse solution is derived which shows uniqueness of model parameter and boundary condition (including paleoprecipitation) estimation, for the specified flow model. Recent expressions of the conventional chloride mass balance technique are derived from the general model presented here; the conventional CMB is shown to be fully compatible with this transient flow model and it requires the steady-state assumption on chloride mass deposition only (and not on water fluxes or boundary conditions). The solutions and results are demonstrated on chloride profile data from west central New Mexico.
Ginn, T.R.; Murphy, E.M.
Tracer Equivalent Latitude: A Diagnostic Tool for Isentropic Transport Studies
Area equivalent latitude based on potential vorticity (PV) is a widely used diagnostic for isentropic transport in the stratosphere and upper troposphere. Here, an alternate method for calculating equivalent latitude is explored, namely, a ...
Douglas R. Allen; Noboru Nakamura
A Preliminary Analysis of the Economics of Using Distributed Energy as a Source of Reactive Power Supply
A major blackout affecting 50 million people in the Northeast United States, where insufficient reactive power supply was an issue, and an increased number of filings made to the Federal Energy Regulatory Commission by generators for reactive power has led to a closer look at reactive power supply and compensation. The Northeastern Massachusetts region is one such area where there is an insufficiency in reactive power compensation. Distributed energy due to its close proximity to loads seems to be a viable option for solving any present or future reactive power shortage problems. Industry experts believe that supplying reactive power from synchronized distributed energy sources can be 2 to 3 times more effective than providing reactive support in bulk from longer distances at the transmission or generation level. Several technology options are available to supply reactive power from distributed energy sources such as small generators, synchronous condensers, fuel cells or microturbines. In addition, simple payback analysis indicates that investments in DG to provide reactive power can be recouped in less than 5 years when capacity payments for providing reactive power are larger than $5,000/kVAR and the DG capital and installation costs are lower than $30/kVAR. However, the current institutional arrangements for reactive power compensation present a significant barrier to wider adoption of distributed energy as a source of reactive power. Furthermore, there is a significant difference between how generators and transmission owners/providers are compensated for reactive power supplied. The situation for distributed energy sources is even more difficult, as there are no arrangements to compensate independent DE owners interested in supplying reactive power to the grid other than those for very large IPPs. There are comparable functionality barriers as well, as these smaller devices do not have the control and communications requirements necessary for automatic operation in response to local or system operators. There are no known distributed energy asset owners currently receiving compensation for reactive power supply or capability. However, there are some cases where small generators on the generation and transmission side of electricity supply have been tested and have installed the capability to be dispatched for reactive power support. Several concerns need to be met for distributed energy to become widely integrated as a reactive power resource. The overall costs of retrofitting distributed energy devices to absorb or produce reactive power need to be reduced. There needs to be a mechanism in place for ISOs/RTOs to procure reactive power from the customer side of the meter where distributed energy resides. Novel compensation methods should be introduced to encourage the dispatch of dynamic resources close to areas with critical voltage issues. The next phase of this research will investigate in detail how different options of reactive power producing DE can compare both economically and functionally with shunt capacitor banks. Shunt capacitor banks, which are typically used for compensating reactive power consumption of loads on distribution systems, are very commonly used because they are very cost effective in terms of capital costs. However, capacitor banks can require extensive maintenance especially due to their exposure to lightning at the top of utility poles. Also, it can be problematic to find failed capacitor banks and their maintenance can be expensive, requiring crews and bucket trucks which often requires total replacement. Another shortcoming of capacitor banks is the fact that they usually have one size at a location (typically sized as 300, 600, 900 or 1200kVAr) and thus don't have variable range as do reactive power producing DE, and cannot respond to dynamic reactive power needs. Additional future work is to find a detailed methodology to identify the hidden benefit of DE for providing reactive power and the best way to allocate the benefit among customers, utilities, transmission companies or RTOs.
Li, Fangxing [ORNL; Kueck, John D [ORNL; Rizy, D Tom [ORNL; King, Thomas F [ORNL
Three-Dimensional Tracer Structure and Behavior as Simulated in Two Ozone Precursor Experiments
The GFDL 11-level general circulation/tracer model is used for two experiments designed to prepare the way for a self-consistent model of atmospheric ozone. The first experiment invokes a very simple condition at the top model level, an ...
J. D. Mahlman; H. Levy; W. J. Moxim
The Obduction of Equatorial 13�C Water in the Pacific Identified by a Simulated Passive Tracer
The obduction of equatorial 13�C Water in the Pacific is investigated using a simulated passive tracer of the Consortium for Estimating the Circulation and Climate of the Ocean (ECCO). The result shows that the 13�C Water initialized in the ...
Tangdong Qu; Shan Gao; Ichiro Fukumori; Rana A. Fine; Eric J. Lindstrom
Assimilation of Stratospheric Chemical Tracer Observations Using a Kalman Filter. Part I: Formulation
The first part of this two-part article describes the formulation of a Kalman filter system for assimilating limb-sounding observations of stratospheric chemical constituents into a tracer transport model. The system is based on a two-dimensional ...
Richard M�nard; Stephen E. Cohn; Lang-Ping Chang; Peter M. Lyster
A Wavelet-Based Reduced Rank Kalman Filter for Assimilation of Stratospheric Chemical Tracer Observations
A suboptimal Kalman filter system that evolves error covariances in terms of a truncated set of wavelet coefficients has been developed for the assimilation of chemical tracer observations of CH4. The truncation is carried out in such a way that ...
Ludovic Auger; Andrew V. Tangborn
On parameterization of the inverse problem for estimating aquifer properties using tracer data
for estimating aquifer properties using tracer data, Water Resour. Res., 48, W06535, doi:10.1029/2011WR011203. 1. However, the calibration of distributed ground- water models based on limited measurements is generally or smoothing in the property of interest, to make underdetermined inverse problems well posed [Yeh, 1986
Hubbard, Susan
Hydrogeophysical tracking of three-dimensional tracer migration: The concept and application of apparent
conductivity and water content [e.g., Binley et al., 2002; Yeh et al., 2002], and has been successfully used, Water Resour. Res., 42, W06422, doi:10.1029/2005WR004568. 1. Introduction [2] We use cross the geophysical parameter values measured in the field to properties such as water content or tracer concentration
Using chemical tracers in hillslope soils to estimate the importance of chemical denudation under
Using chemical tracers in hillslope soils to estimate the importance of chemical denudation under mass. The model includes both sediment transport and chemical denudation. A simplified two-phase model is developed; the two phases are a chemically immobile phase, which has far lower solubility than the bulk soil
Lagrangian and Tracer Evolution in the Vicinity of an Unstable Jet
The dynamics of Lagrangian particles and tracers in the vicinity of a baroclinically unstable zonal jet are investigated in a simple two-layer model with an initially quiescent lower layer. The presence of a growing wave induces a particle drift ...
Emmanuel Boss; Lu Anne Thompson
Use of Passive Tracers as a Diagnostic Tool in Coupled Model Simulations�Northern Hemisphere
This study focuses on the uptake of a passive idealized tracer in the Northern Hemisphere oceans from two coupled ocean�atmosphere simulations: a standard horizontal diffusion case and the second case including the Gent and McWilliams (GM) eddy ...
Siobhan P. O'Farrell
Quantification of the Lateral Boundary Forcing of a Regional Climate Model Using an Aging Tracer
The present work introduces a new and useful tool to quantify the lateral boundary forcing of a regional climate model (RCM). This tool, an aging tracer, computes the time the air parcels spend inside the limited-area domain of an RCM. The aging ...
Philippe Lucas-Picher; Daniel Caya; S�bastien Biner; Ren� Laprise
Total Matrix Intercomparison: A Method for Determining the Geometry of Water-Mass Pathways
Ocean tracer distributions have long been used to decompose the deep ocean into constituent water masses, but previous inverse methods have generally been limited to just a few water masses that have been defined by a subjective choice of static ...
Geoffrey Gebbie; Peter Huybers
Nuclear engine flow reactivity shim control
A nuclear engine control system is provided which automatically compensates for reactor reactivity uncertainties at the start of life and reactivity losses due to core corrosion during the reactor life in gas-cooled reactors. The coolant gas flow is varied automatically by means of specially provided control apparatus so that the reactor control drums maintain a predetermined steady state position throughout the reactor life. This permits the reactor to be designed for a constant drum position and results in a desirable, relatively flat temperature profile across the core. (Official Gazette)
Walsh, J.M.
Radon as an In Situ Tracer in Geothermal Reservoirs
By measuring trace amounts of radon in geothermal steam, utilities can estimate changes in the properties of the fluid produced from a reservoir. These measurements provide a method to monitor the transition from a liquid-dominated reservoir to a boiling reservoir.
Applications of Ensemble-based Data Assimilation Techniques for Aquifer Characterization using Tracer Data at Hanford 300 Area
Subsurface aquifer characterization often involves high parameter dimensionality and requires tremendous computational resources if employing a full Bayesian approach. Ensemble-based data assimilation techniques, including filtering and smoothing, are computationally efficient alternatives. Despite the increasing number of applications of ensemble-based methods in assimilating flow and transport related data for subsurface aquifer charaterization, most are limited to either synthetic studies or two-dimensional problems. In this study, we applied ensemble-based techniques for assimilating field tracer experimental data obtained from the Integrated Field Research Challenge (IFRC) site at the Hanford 300 Area. The forward problem was simulated using the massively-parallel three-dimensional flow and transport code PFLOTRAN to effectively deal with the highly transient flow boundary conditions at the site and to meet the computational demands of ensemble-based methods. This study demonstrates the effectiveness of ensemble-based methods for characterizing a heterogeneous aquifer by sequentially assimilating multiple types of data. The necessity of employing high performance computing is shown to enable increasingly mechanistic non-linear forward simulations to be performed within the data assimilation framework for a complex system with reasonable turnaround time.
Chen, Xingyuan; Hammond, Glenn E.; Murray, Christopher J.; Rockhold, Mark L.; Vermeul, Vincent R.; Zachara, John M.
Neutron Radiography Reactor Reactivity -- Focused Lessons Learned
As part of the Global Threat Reduction Initiative, the Neutron Radiography Reactor (NRAD) at the Idaho National Laboratory (INL) was converted from using highly enriched uranium (HEU) to low enriched uranium (LEU) fuel. After the conversion, NRAD resumed operations and is meeting operational requirements. Radiography image quality and the number of images that can be produced in a given time frame match pre-conversion capabilities. However, following the conversion, NRAD�s excess reactivity with the LEU fuel was less than it had been with the HEU fuel. Although some differences between model predictions and actual performance are to be expected, the lack of flexibility in NRAD�s safety documentation prevented adjusting the reactivity by adding more fuel, until the safety documentation could be modified. To aid future reactor conversions, a reactivity-focused Lessons Learned meeting was held. This report summarizes the findings of the lessons learned meeting and addresses specific questions posed by DOE regarding NRAD�s conversion and reactivity.
Eric Woolstenhulme; Randal Damiana; Kenneth Schreck; Ann Marie Phillips; Dana Hewit
LES algorithm for turbulent reactive flows simulation
The paper presents the development and implementation of a Large Eddy Simulation numerical algorithm for simulating turbulent reactive flows. The numerical algorithm is based on a 5 step modified Runge - Kutta numerical scheme with a dual time stepping ... Keywords: Runge - Kutta numerical scheme, large eddy simulation, linear eddy model
Ionut Porumbel; Cristian C�rl?nescu; Florin Gabriel Florean; Constantin Eusebiu Hritcu
Reactive burn models and ignition & growth concept
Plastic-bonded explosives are heterogeneous materials. Experimentally, shock initiation is sensitive to small amounts of porosity, due to the formation of hot spots (small localized regions of high temperature). This leads to the Ignition and Growth concept, introduced by Lee and Tarver in 1980, as the basis for reactive burn models. A homogeneized burn rate needs to account for three mesoscale physical effects (i) the density of burnt hot spots, which depends on the lead shock strength; (ii) the growth of the burn fronts triggered by hot spots, which depends on the local deflagration speed; (iii) a geometric factor that accounts for the overlap of deflagration wavelets from adjacent hot spots. These effects can be combined and the burn model defined by specifying the reaction progress variable {lambda}(t) as a function of a dimensionless reaction length {tau}{sub hs}(t)/{ell}{sub hs}, rather than by xpecifying an explicit burn rate. The length scale {ell}{sub hs} is the average distance between hot spots, which is proportional to [N{sub hs}(P{sub s})]{sup -1/3}, where N{sub hs} is the number density of hot spots activated by the lead shock. The reaction length {tau}{sub hs}(t) = {line_integral}{sub 0}{sup t} D(P(t'))dt' is the distance the burn front propagates from a single hot spot, where D is the deflagration speed and t is the time since the shock arrival. A key implementation issue is how to determine the lead shock strength in conjunction with a shock capturing scheme. They have developed a robust algorithm for this purpose based on the Hugoniot jump condition for the energy. The algorithm utilizes the time dependence of density, pressure and energy within each cell. The method is independent of the numerical dissipation used for shock capturing. It is local and can be used in one or more space dimensions. The burn model has a small number of parameters which can be calibrated to fit velocity gauge data from shock initiation experiments.
Menikoff, Ralph S [Los Alamos National Laboratory; Shaw, Milton S [Los Alamos National Laboratory
The stabilities of several tracers were tested under geothermal conditions while injection-backflow tests were conducted at East Mesa. The tracers I and Br were injected continuously while SCN (thiocyanate), B, and disodium fluorescein were each injected as a point source (slug). The tracers were shown to be stable, except where the high concentrations used during slug injection induced adsorption of the slug tracers. However, adsorption of the slug tracers appeared to ''armor'' the formation against adsorption during subsequent tests. Precipitation behavior of calcite and silica as well as Na/K shifts during injection are also discussed.
Adams, M.C.
TRACER DETECTION TECHNOLOGY CORP. TRACER DETECTION TECHNOLOGY CORP. PRODUCTS AND SERVICES FOR CORPORATE AND GOVERNMENT SECURITY 3463 MAGIC DRIVE, SUITE T-19 SAN ANTONIO, TX 78229 March 29, 2009 Office of the Assistant General Counsel for Technology Transfer and Intellectual Property U.S. Department of Energy 1000 Independence Ave., SW. Washington, DC 20585. email@example.com ATTN: TECHNOLOGY TRANSFER QUESTIONS. Response to Request for Information - Federal Register "The Costs and Benefits of Dealing with Federal Laboratories" This "white paper" is intended to deal constructively with issues relating to technology transfer and interaction of small businesses with federal laboratories, and should be considered a response to #6 (other). As a small businessman and entrepreneur engaged in the
Evaluation of Tracers for Use in the International Field Experiment on CO2 Ocean Sequestration
Tracers for Use in the International Field Experiment Tracers for Use in the International Field Experiment on CO 2 Ocean Sequestration E. Eric Adams (email@example.com; 617-253-6595) Dept. of Civil and Environmental Engineering Massachusetts Institute of Technology Cambridge, MA 02139 USA Introduction An international field experiment is scheduled to take place off of the west coast of the big island of Hawaii during the second half of 2001 (Adams, et al., 1999; Herzog, et al., 2000). Scientists representing some dozen institutions in five countries on four continents are expected to participate. The experiment will involve several sub-experiments in which CO 2 will be released at a depth of 800 m as a buoyant liquid at rates of 0.1 to 1.0 kg/s. The releases will each be made for a duration of about one hour using nozzles with differing diameters and numbers of ports.
In searching for high gravimetric and volumetric density hydrogen storage systems, it is inevitable that higher energy density materials will be used. In order to make safe and commercially acceptable condensed phase hydrogen storage systems, it is important to understand quantitatively the risks involved in using and handling these materials and to develop appropriate mitigation strategies to handle potential material exposure events. A crucial aspect of the development of risk identification and mitigation strategies is the development of rigorous environmental reactivity testing standards and procedures. This will allow for the identification of potential risks and implementation of risk mitigation strategies. Modified testing procedures for shipping air and/or water sensitive materials, as codified by the United Nations, have been used to evaluate two potential hydrogen storage materials, 2LiBH{sub 4} {center_dot} MgH{sub 2} and NH{sub 3}BH{sub 3}. The modified U.N. procedures include identification of self-reactive substances, pyrophoric substances, and gas-emitting substances with water contact. The results of these tests for air and water contact sensitivity will be compared to the pure material components where appropriate (e.g. LiBH{sub 4} and MgH{sub 2}). The water contact tests are divided into two scenarios dependent on the hydride to water mole ratio and heat transport characteristics. Air contact tests were run to determine whether a substance will spontaneously react with air in a packed or dispersed form. In the case of the 2LiBH{sub 4} {center_dot} MgH{sub 2} material, the results from the hydride mixture compared to the pure materials results showed the MgH{sub 2} to be the least reactive component and LiBH{sub 4} the more reactive. The combined 2LiBH{sub 4} {center_dot} MgH{sub 2} resulted in a material having environmental reactivity between these two materials. Relative to 2LiBH{sub 4} {center_dot} MgH{sub 2}, the chemical hydride NH{sub 3}BH{sub 3} was observed to be less environmentally reactive.
Gray, J; Donald Anton, D
Ongoing Phase 2-3 work comprises the final development and field-testing of two complementary real-time reservoir technologies; a stimulation process and a tracer fracturing diagnostic system. Initial DE-FC26-99FT40129 project work included research, development, and testing of the patented gamma tracer fracturing diagnostic system. This process was field-proven to be technically useful in providing tracer measurement of fracture height while fracturing; however, technical licensing restrictions blocked Realtimezone from fully field-testing this real-time gamma diagnostic system, as originally planned. Said restrictions were encountered during Phase 2 field test work as result of licensing limitations and potential conflicts between service companies participating in project work, as related to their gamma tracer logging tool technology. Phase 3 work principally demonstrated field-testing of Realtimezone (RTZ) and NETL's Downhole-mixed Reservoir Stimulation process. Early on, the simplicity of and success of downhole-mixing was evident from well tests, which were made commercially productive. A downhole-mixed acid stimulation process was tested successfully and is currently commercially used in Canada. The fourth well test was aborted due to well bore conditions, and an alternate test project is scheduled April, 2004. Realtimezone continues to effectuate ongoing patent protection in the United States and foreign markets. In 2002, Realtimezone and the NETL licensed their United States patent to Halliburton Energy Services (HES). Additional licensing arrangements with other industry companies are anticipated in 2004-2005. Ongoing Phase 2 and Phase 3 field-testing continues to confirm applications of both real-time technologies. Technical data transfer to industry is ongoing via Internet tech-transfer and various industry presentations and publications including Society of Petroleum Engineers. These real-time enhanced stimulation procedures should significantly increase future petroleum well recoveries in the United States, onshore and offshore, and in vertical and horizontal wells.
George Scott III
Behavior of Laminate Reactive Materials under Dynamic Loading ...
Presentation Title, Behavior of Laminate Reactive Materials under Dynamic Loading ... Atomistically-Informed Dislocation Dynamics Simulations of High Rate �...
SIC Manufature via Reactive Infiltration - Programmaster.org
About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Ceramic Matrix Composites. Presentation Title, SIC Manufature via Reactive�...
Retention of Tracer Gas from Instantaneous Releases of SF6 in an Urban Environment
Data from a series of instantaneous releases of SF6 tracer during the Joint Urban 2003 study in Oklahoma City have been analyzed to determine characteristic retention times for puffs in an urban environment. Results from nine real-time tracer detectors with a time response of 0.5 seconds were used in the analysis. Distances from the source ranged from less than 200 m to over 1 km. For each individual intensive operating period (IOP), the detector locations were adjusted so that, given the expected wind directions during the releases, the detectors would lie generally downwind of the release point. As a result, building characteristics upwind of the detectors varied from one IOP to the next. Animations of the tracer concentrations show clear evidence of channeling along street canyons approximately parallel to the prevailing wind directions, trapping in street canyons perpendicular to the flow, and other complex circulation patterns. Retention times for individual puffs ranged from a few minutes to over 20 minutes, with a strong mode in the distribution around 11 minutes. There was surprisingly little correlation with wind speed or direction. Comparisons with simple puff models are presented.
Doran, J. C.; Allwine, K Jerry; Clawson, Kirk L.; Carter, Roger G.
Subduction of South Pacific Tropical Water and Its Equatorward Pathways as Shown by a Simulated Passive Tracer
This study investigates the subduction of South Pacific Tropical Water (SPTW) and its equatorward pathways using a simulated passive tracer of the consortium Estimating the Circulation & Climate of the Ocean (ECCO). The results show that ...
Tangdong Qu; Shan Gao; Rana A. Fine
Origin and Pathway of Equatorial 13�C Water in the Pacific Identified by a Simulated Passive Tracer and Its Adjoint
The origin and pathway of the thermostad water in the eastern equatorial Pacific Ocean, often referred to as the equatorial 13�C Water, are investigated using a simulated passive tracer and its adjoint, based on circulation estimates of a global ...
Nocturnal Low-Level Jet in a Mountain Basin Complex. Part II: Transport and Diffusion of Tracer under Stable Conditions
Differences in nighttime transport and diffusion of sulfur hexafluoride (SF6) tracer in an urban complex-terrain setting (Salt Lake City, Utah) are investigated using surface and Doppler lidar wind data and large-scale surface pressure ...
Lisa S. Darby; K. Jerry Allwine; Robert M. Banta
Nuclear reactivity control using laser induced polarization
A control element for reactivity control of a fission source provides an atomic density of .sup.3 He in a control volume which is effective to control criticality as the .sup.3 He is spin-polarized. Spin-polarization of the .sup.3 He affects the cross section of the control volume for fission neutrons and hence, the reactivity. An irradiation source is directed within the .sup.3 He for spin-polarizing the .sup.3 He. An alkali-metal vapor may be included with the .sup.3 He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with .sup.3 He to spin-polarize the .sup.3 He atoms.
Bowman, Charles D. (Los Alamos, NM)
A control element for reactivity control of a fission source provides an atomic density of .sup.3 He in a control volume which is effective to control criticality as the .sup.3 He is spin-polarized. Spin-polarization of the .sup.3 He affects the cross section of the control volume for fission neturons and hence, the reactivity. An irradiation source is directed within the .sup.3 He for spin-polarizing the .sup.3 He. An alkali-metal vapor may be included with the .sup.3 He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with .sup.3 He to spin-polarize the .sup.3 He atoms.
Reactivity control assembly for nuclear reactor. [LMFBR
This invention, which resulted from a contact with the United States Department of Energy, relates to a control mechanism for a nuclear reactor and, more particularly, to an assembly for selectively shifting different numbers of reactivity modifying rods into and out of the core of a nuclear reactor. It has been proposed heretofore to control the reactivity of a breeder reactor by varying the depth of insertion of control rods (e.g., rods containing a fertile material such as ThO/sub 2/) in the core of the reactor, thereby varying the amount of neutron-thermalizing coolant and the amount of neutron-capturing material in the core. This invention relates to a mechanism which can advantageously be used in this type of reactor control system.
Bollinger, L.R.
Treatment of Radioactive Reactive Mixed Waste
PacificEcoSolutions, Inc. (PEcoS) has installed a plasma gasification system that was recently modified and used to destroy a trimethyl-aluminum mixed waste stream from Los Alamos National Laboratory (LANL.) The unique challenge in handling reactive wastes like trimethyl-aluminum is their propensity to flame instantly on contact with air and to react violently with water. To safely address this issue, PacificEcoSolutions has developed a new feed system to ensure the safe containment of these radioactive reactive wastes during transfer to the gasification unit. The plasma gasification system safely processed the radioactively contaminated trimethyl-metal compounds into metal oxides. The waste stream came from LANL research operations, and had been in storage for seven years, pending treatment options. (authors)
Colby, S.; Turner, Z.; Utley, D. [Pacific EcoSolutions, Inc., 2025 Battelle Boulevard, Richland, Washington 99354 (United States); Duy, C. [Los Alamos National Laboratory - LA-UR-05-8410, Post Office Box 1663 MS J595, Los Alamos, New Mexico 97545 (United States)
A control element for reactivity control of a fission source provides an atomic density of {sup 3}He in a control volume which is effective to control criticality as the {sup 3}He is spin-polarized. Spin-polarization of the {sup 3}He affects the cross section of the control volume for fission neutrons and hence, the reactivity. An irradiation source is directed within the {sup 3}He for spin-polarizing the {sup 3}He. An alkali-metal vapor may be included with the {sup 3}He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with {sup 3}He to spin-polarize the {sup 3}He atoms. 5 figs.
Bowman, C.D.
Real time reactive programming in lucid enriched with contexts
We present a synchronous approach to real-time reactive programming in Lucid enriched with contexts as first class objects. The declarative intensional approach allows real-time reactive programs to manipulate both events and state-based representations ... Keywords: contexts, formal verification, intensional programming, real-time reactive programming
Kaiyu Wan; Vasu Alagar; Joey Paquet
The Reactive Light Yellow Dye Wastewater Treatment by Sewage Sludge-Based Activated Carbon
The paper is aim to discuss the dye wastewater treatment by sewage sludge-based adsorbent. The adsorbent derived from sewage sludge, which produced through phosphoric acid-microwave method, and commercia activated carbon (ACC) were tested in the process ... Keywords: Sewage Sludge-based Activated Carbon (ACSS), the Reactive Light Yellow, Dye Wastewater, Adsorption
Yang Lijun; Dai Qunwei
Gas chromatograph-mass spectrometer (GC/MS) system for quantitative analysis of reactive chemical compounds
Described is a new gas chromatograph-mass spectrometer (GC/MS) system and method for quantitative analysis of reactive chemical compounds. All components of such a GC/MS system external to the oven of the gas chromatograph are programmably temperature controlled to operate at a volatilization temperature specific to the compound(s) sought to be separated and measured.
Grindstaff, Quirinus G. (Oak Ridge, TN)
Quantification of multiple methane emission sources at landfills using a double tracer technique
Research highlights: > Precise and reliable measurements of emissions from landfills are needed. > A tracer technique involving simultaneous release of two tracers was proven successful. > Measurements to be performed at times with low changing trends in barometric pressure. - Abstract: A double tracer technique was used successfully to quantify whole-site methane (CH{sub 4}) emissions from Fakse Landfill. Emissions from different sections of the landfill were quantified by using two different tracers. A scaled-down version of the tracer technique measuring close-by to localized sources having limited areal extent was also used to quantify emissions from on-site sources at the landfill facility, including a composting area and a sewage sludge storage pit. Three field campaigns were performed. At all three field campaigns an overall leak search showed that the CH{sub 4} emissions from the old landfill section were localized to the leachate collection wells and slope areas. The average CH{sub 4} emissions from the old landfill section were quantified to be 32.6 {+-} 7.4 kg CH{sub 4} h{sup -1}, whereas the source at the new section was quantified to be 10.3 {+-} 5.3 kg CH{sub 4} h{sup -1}. The CH{sub 4} emission from the compost area was 0.5 {+-} 0.25 kg CH{sub 4} h{sup -1}, whereas the carbon dioxide (CO{sub 2}) and nitrous oxide (N{sub 2}O) flux was quantified to be in the order of 332 {+-} 166 kg CO{sub 2} h{sup -1} and 0.06 {+-} 0.03 kg N{sub 2}O h{sup -1}, respectively. The sludge pit located west of the compost material was quantified to have an emission of 2.4 {+-} 0.63 kg h{sup -1} CH{sub 4}, and 0.03 {+-} 0.01 kg h{sup -1} N{sub 2}O.
Scheutz, C., E-mail: email@example.com [Department of Environmental Engineering, Technical University of Denmark, Miljovej, Building 113, 2800 Kongens Lyngby (Denmark); Samuelsson, J., E-mail: firstname.lastname@example.com [Chalmers University of Technology/FluxSense AB, SE-412 96 Goeteborg (Sweden); Fredenslund, A.M., E-mail: firstname.lastname@example.com [Department of Environmental Engineering, Technical University of Denmark, Miljovej, Building 113, 2800 Kongens Lyngby (Denmark); Kjeldsen, P., E-mail: email@example.com [Department of Environmental Engineering, Technical University of Denmark, Miljovej, Building 113, 2800 Kongens Lyngby (Denmark)
Cold Reactive Collisions between Laser-Cooled Ions and Velocity-Selected Neutral Molecules
We report a new experimental method to study reactive ion-molecule collisions at very low temperatures. A source of laser-cooled ions in a linear Paul trap has been combined with a quadrupole-guide velocity selector to investigate the reaction of Ca{sup +} with CH{sub 3}F at collision energies E{sub coll}/k{sub B}{>=}1 K with single-particle sensitivity. The technique represents a general approach to study reactive collisions between ions and polar molecules over a wide temperature range down to the cold regime.
Willitsch, Stefan; Bell, Martin T.; Gingell, Alexander D.; Procter, Simon R.; Softley, Timothy P. [Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA (United Kingdom)
A semi-analytical model for heat and mass transfer in geothermal reservoirs to estimate fracture surface-are-to-volume ratios and thermal breakthrough using thermally-decaying and diffusing tracers
A semi-analytical model was developed to conduct rapid scoping calculations of responses of thermally degrading and diffusing tracers in multi-well tracer tests in enhanced geothermal systems (EGS). The model is based on an existing Laplace transform inversion model for solute transport in dual-porosity media. The heat- and mass-transfer calculations are decoupled and conducted sequentially, taking advantage of the fact that heat transfer between fractures and the rock matrix is much more rapid than mass transfer and therefore mass transfer will effectively occur in a locally isothermal system (although the system will be nonisothermal along fracture flow pathways, which is accounted for by discretizing the flow pathways into multiple segments that have different temperature histories). The model takes advantage of the analogies between heat and mass transfer, solving the same governing equations with k{sub m}/({rho}C{sub p}){sub w} being substituted for {phi}D{sub m} in the equation for fracture transport and k{sub m}/({rho}C{sub p}){sub m} being subsituted for D{sub m} in the equation for matrix transport; where k = thermal conductivity (cal/cm-s-K), {rho} = density (g/cm{sup 3}), C{sub p} = heat capacity (at constant pressure) (cal/g-K), {phi} = matrix porosity, and D = tracer diffusion coefficient (cm{sup 2}/s), with the subscripts w and m referring to water and matrix, respectively. A significant advantage of the model is that it executes in a fraction of second on a single-CPU personal computer, making it very amenable for parameter estimation algorithms that involve repeated runs to find global minima. The combined thermal-mass transport model was used to evaluate the ability to estimate when thermal breakthrough would occur in a multi-well EGS configuration using thermally degrading tracers. Calculations were conducted to evaluate the range of values of Arrhenius parameters, A and E{sub {alpha}} (pre-exponential factor, 1/s, and activation energy, cal/mol) required to obtain interpretable responses of thermally-degrading tracers that decay according to the rate constant k{sub d} = Ae{sup -E{sub {alpha}}/RT}, where k{sub d} = decay rate constant (1/s), R = ideal gas constant (1.987 cal/mol-K), and T = absolute temperature (K). It is shown that there are relatively narrow ranges of A and E{sub {alpha}} that will result in readily interpretable tracer responses for any given combination of ambient reservoir temperature and working fluid residence time in a reservoir. The combined model was also used to simulate the responses of conservative tracers with different diffusion coefficients as a way of estimating fracture surface-area-to-volume ratios (SA/V) in multi-well EGS systems. This method takes advantage of the fact that the differences in breakthrough curves of tracers with different matrix diffusion coefficients are a function of SA/V. The model accounts for differences in diffusion coefficients as a function of temperature so that tracer responses obtained at different times can be used to obtain consistent estimates of SA/V as the reservoir cools down. Some single-well applications of this approach are simulated with a numerical model to demonstrate the potential to evaluate the effectiveness of EGS stimulations before a second well is drilled.
Uranium-233 (t{sub 1/2} {approx} 1.59E5 years) is an artificial, fissile isotope of uranium that has significant importance in nuclear forensics. The isotope provides a unique signature in determining the origin and provenance of uranium-bearing materials and is valuable as a mass spectrometric tracer. Alpha spectrometry was employed in the critical evaluation of a {sup 233}U standard reference material (SRM-995) as a dual tracer system based on the in-growth of {sup 229}Th (t{sub 1/2} {approx} 7.34E3 years) for {approx}35 years following radiochemical purification. Preliminary investigations focused on the isotopic analysis of standards and unmodified fractions of SRM-995; all samples were separated and purified using a multi-column anion-exchange scheme. The {sup 229}Th/{sup 233}U atom ratio for SRM-995 was found to be 1.598E-4 ({+-} 4.50%) using recovery-corrected radiochemical methods. Using the Bateman equations and relevant half-lives, this ratio reflects a material that was purified {approx} 36.8 years prior to this analysis. The calculated age is discussed in contrast with both the date of certification and the recorded date of last purification.
Beals, D.
Prediction of thermal front breakthrough due to fluid reinjection in geothermal reservoirs
Chemically reactive tracers can be used to measure reservoir temperature distributions because of their extreme sensitivity to temperature. If a reactive tracer flows through a reservoir from an injection well to a production well, then early in the production history the tracer will contact mostly high temperatures and experience a high percentage of decomposition. As more energy is extracted from the reservoir, subsequent reactive tracer tests will show less decomposition. Tracers must be chosen which have reaction kinetics appropriate to the temperature patterns expected in the reservoir under consideration. If kinetics are too slow, no significant reaction occurs. If kinetics are too fast, essentially all of the tracer will react. In neither case can useful information be obtained. Seventeen chemically reactive tracers have been identified which are appropriate for geothermal reservoirs in the 70 to 275/sup 0/C range. Of the 17 tracer reactions investigated, 5 are hydrolysis of esters, 3 are hydrolysis of amines, and 9 are hydrolysis of aryl halides. A method for choice of the appropriate reactive tracer for a given reservoir is also presented. The method requires measurement of the residence time distribution (from a conservative tracer test), an estimate of reservoir temperature, and some simple geochemistry measurements and calculations. Several examples of choosing reactive tracers for existing geothermal reservoirs are given.
Birdsell, S.A.; Robinson, B.A.
A HPLC method for the quantification of butyramide and acetamide at ppb levels in hydrogeothermal waters
A quantitative analytical method to determine butyramide and acetamide concentrations at the low ppb levels in geothermal waters has been developed. The analytes are concentrated in a preparation step by evaporation and analyzed using HPLC-UV. Chromatographic separation is achieved isocratically with a RP C-18 column using a 30 mM phosphate buffer solution with 5 mM heptane sulfonic acid and methanol (98:2 ratio) as the mobile phase. Absorbance is measured at 200 nm. The limit of detection (LOD) for BA and AA were 2.0 {mu}g L{sup -1} and 2.5 {mu}g L{sup -1}, respectively. The limit of quantification (LOQ) for BA and AA were 5.7 {mu}g L{sup -1} and 7.7 {mu}g L{sup -1}, respectively, at the detection wavelength of 200 nm. Attaining these levels of quantification better allows these amides to be used as thermally reactive tracers in low-temperature hydrogeothermal systems.
Gracy Elias; Earl D. Mattson; Jessica E. Little
Anode reactive bleed and injector shift control strategy
A system and method for correcting a large fuel cell voltage spread for a split sub-stack fuel cell system. The system includes a hydrogen source that provides hydrogen to each split sub-stack and bleed valves for bleeding the anode side of the sub-stacks. The system also includes a voltage measuring device for measuring the voltage of each cell in the split sub-stacks. The system provides two levels for correcting a large stack voltage spread problem. The first level includes sending fresh hydrogen to the weak sub-stack well before a normal reactive bleed would occur, and the second level includes sending fresh hydrogen to the weak sub-stack and opening the bleed valve of the other sub-stack when the cell voltage spread is close to stack failure.
Cai, Jun [Rochester, NY; Chowdhury, Akbar [Pittsford, NY; Lerner, Seth E [Honeoye Falls, NY; Marley, William S [Rush, NY; Savage, David R [Rochester, NY; Leary, James K [Rochester, NY
Reactive gas atomization processing for Fe-based ODS alloys
Gas atomization reaction synthesis was employed as a simplified method for processing oxide dispersion forming precursor Fe-based powders (e.g., Fe-Cr-Y-Hf). During this process a reactive atomization gas (i.e., Ar-O{sub 2}) was used to oxidize the powder surfaces during primary break-up and rapid solidification of the molten alloy. This resulted in envelopment of the powders by an ultra-thin (t dispersion strengthened microstructures were engineered from different powder particle size ranges, illustrating microstructural control as a function of particle solidification rate. Additionally, preliminary thermal-mechanical processing was used to develop a fine scale dislocation substructure for ultimate strengthening of the alloy.
Rieken, J.R.; Anderson, I.E.; Kramer, M.J.; Odette, G.R.; Stergarc, E.; Haney, E.
FirstEnergy Uses EPRI Interregional Reactive Power Management Framework to Help Improve Transmission Voltage Stability
FirstEnergy teamed with EPRI and Powertech Labs to develop a practical, automated method for identifying areas prone to voltage instability due to a lack of reactive power reserves. Power system designers and operational planning engineers can use the new method to evaluate the performance of various power system designs or configurations with regard to susceptibility to voltage instability, determine weak areas requiring special remediation, and maximize the efficient use of assets by determining the mi...
Preparation of reactive beta-dicalcium silicate
This invention relates to the preparation of fine particles of reactive beta-dicalcium silicate by means of a solid state process which comprises firing a mixture of calcium sulfate, silica, and a reducing additive selected from the group consisting of calcium sulfide, carbon, carbon monoxide, methane, and hydrogen, at a temperature of about 850 to 1000/sup 0/C. A carrier gas such as nitrogen or carbon dioxide may also be added, if desired. A high concentration of sulfur dioxide is a by-product of this process.
Shen, M.S.; Chen, J.M.; Yang, R.T.
This invention relates to the preparation of fine particles of reactive beta-dicalcium silicate by means of a solid state process which comprises firing a mixture of calcium sulfate, silica and a reducing additive selected from the group consisting of calcium sulfide, carbon, carbon monoxide, methane and hydrogen, at a temperature of about 850.degree.-1000.degree. C. A carrier gas such as nitrogen or carbon dioxide may also be added, if desired. A high concentration of sulfur dioxide is a by-product of this process.
Shen, Ming-Shing (Laramie, WY, NJ); Chen, James M. (Rahway, NJ); Yang, Ralph T. (Amherst, NY)
Reactive sticking coefficients of silane on silicon
Reactive sticking coefficients (RSCs) were measured for silane and disilane on polycrystalline silicon for a wide range of temperature and flux (pressure) conditions. The data were obtained from deposition rate measurements using molecular beam scattering and a very low pressure cold wall reactor. The RSCs have non-Arrhenius temperature dependences and decreases with increasing flux at low (710/sup 0/) temperatures. A simple model involving dissociative adsorption of silane is consistent with these results. The results are compared with previous studies of the SiH/sub 4//Si(s) reaction.
Buss, R.J.; Ho, P.; Breiland, W.G.; Coltrin, M.E.
Sensitivity and uncertainty analysis applied to the JHR reactivity prediction
The on-going AMMON program in EOLE reactor at CEA Cadarache (France) provides experimental results to qualify the HORUS-3D/N neutronics calculation scheme used for the design and safety studies of the new Material Testing Jules Horowitz Reactor (JHR). This paper presents the determination of technological and nuclear data uncertainties on the core reactivity and the propagation of the latter from the AMMON experiment to JHR. The technological uncertainty propagation was performed with a direct perturbation methodology using the 3D French stochastic code TRIPOLI4 and a statistical methodology using the 2D French deterministic code APOLLO2-MOC which leads to a value of 289 pcm (1{sigma}). The Nuclear Data uncertainty propagation relies on a sensitivity study on the main isotopes and the use of a retroactive marginalization method applied to the JEFF 3.1.1 {sup 27}Al evaluation in order to obtain a realistic multi-group covariance matrix associated with the considered evaluation. This nuclear data uncertainty propagation leads to a K{sub eff} uncertainty of 624 pcm for the JHR core and 684 pcm for the AMMON reference configuration core. Finally, transposition and reduction of the prior uncertainty were made using the Representativity method which demonstrates the similarity of the AMMON experiment with JHR (the representativity factor is 0.95). The final impact of JEFF 3.1.1 nuclear data on the Begin Of Life (BOL) JHR reactivity calculated by the HORUS-3D/N V4.0 is a bias of +216 pcm with an associated posterior uncertainty of 304 pcm (1{sigma}). (authors)
Leray, O.; Vaglio-Gaudard, C.; Hudelot, J. P.; Santamarina, A.; Noguere, G. [CEA, DER, SPRC, F-13108 St Paul-Lez-Durance (France); Di-Salvo, J. [CEA, DER, SPEx, F-13108 St Paul-Lez-Durance (France)
Local Dynamic Reactive Power for Correction of System Voltage Problems
Distribution systems are experiencing outages due to a phenomenon known as local voltage collapse. Local voltage collapse is occurring in part because modern air conditioner compressor motors are much more susceptible to stalling during a voltage dip than older motors. These motors can stall in less than 3 cycles (.05s) when a fault, such as on the sub-transmission system, causes voltage to sag to 70 to 60%. The reasons for this susceptibility are discussed in the report. During the local voltage collapse, voltages are depressed for a period of perhaps one or two minutes. There is a concern that these local events are interacting together over larger areas and may present a challenge to system reliability. An effective method of preventing local voltage collapse is the use of voltage regulation from Distributed Energy Resources (DER) that can supply or absorb reactive power. DER, when properly controlled, can provide a rapid correction to voltage dips and prevent motor stall. This report discusses the phenomenon and causes of local voltage collapse as well as the control methodology we have developed to counter voltage sag. The problem is growing because of the use of low inertia, high efficiency air conditioner (A/C) compressor motors and because the use of electric A/C is growing in use and becoming a larger percentage of system load. A method for local dynamic voltage regulation is discussed which uses reactive power injection or absorption from local DER. This method is independent, rapid, and will not interfere with conventional utility system voltage control. The results of simulations of this method are provided. The method has also been tested at the ORNL s Distributed Energy Communications and Control (DECC) Laboratory using our research inverter and synchronous condenser. These systems at the DECC Lab are interconnected to an actual distribution system, the ORNL distribution system, which is fed from TVA s 161kV sub-transmission backbone. The test results are also provided and discussed. The simulations and testing show that local voltage control from DER can prevent local voltage collapse. The results also show that the control can be provided so quickly, within 0.5 seconds, that is does not interfere with conventional utility methods.
Kueck, John D [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Xu, Yan [ORNL; Li, Huijuan [University of Tennessee, Knoxville (UTK); Adhikari, Sarina [ORNL; Irminger, Philip [ORNL
Trip Report for the 2005 Sino-American SF6 Tracer Experiment
The Chinese Institute for Radiation Protection (CIRP) conducted an SF6 atmospheric tracer experiment in July 2005 in the vicinity of the Qinshan Nuclear Power Company complex on the coast of the East China Sea. The experiment was partially sponsored by the US Department of Energy National Nuclear Security Administration, under the NA-23 International Emergency Management and Cooperation Program. NA-23 sent a delegation of five scientists to observe the experiment; four of the observers were from Lawrence Livermore National Laboratory (LLNL) and one was from the Japan Atomic Energy Research Institute (JAERI). CIRP's cooperation with the US-Japanese delegation was excellent, and the project was very successful from the international cooperation perspective. Although the experiment was modest in scope, it may provide one or more data sets that can be used for international dispersion model validation and intercomparison projects. Several areas for procedural improvements were noted by the US and Japanese observers, and a more concise measure of the experiment's scientific value will be available after CIRP completes and delivers the database of the experiment results by the end of the fiscal year. The consensus recommendation of the observers is that CIRP and DOE/NNSA NA-23 build on the experience and personal contacts gained during the experiment to plan and conduct an even more effective experiment in the future, perhaps as early as next year (2006). If the decision is made to conduct a follow-on experiment, we strongly recommend that the LLNL and JAERI representatives work cooperatively with CIRP throughout the entire planning phase of the experiment. As discussed in Section V, a 2006 China tracer experiment could serve as a springboard to a 2007 long-range international tracer experiment involving South Korea.
Bradley, M M; Sullivan, T J; Keating II, G A; Leach, M J
Mechanistic Reactive Burn Modeling of Solid Explosives
This report describes a computational framework for reactive burn modeling of solid explosives and the development of a test case where physical mechanisms represent RDX or RDX-based materials. The report is a sequel to LA-13794-MS, ''A Unifying Framework for Hot Spots and the Ignition of Energetic Materials,'' where we proposed a new approach to the building of a general purpose model that captures the essential features of the three primary origins of hot-spot formation: void collapse, shear banding, friction. The purpose of the present report is to describe the continuing task of coupling the unifying hot-spot model to hydrodynamic calculations to develop a mechanistic reactive burn model. The key components of the coupling include energy localization, the growth of hot spots, overall hot-spot behavior, and a phase-averaged mixture equation of state (EOS) in a Mie-Grueneisen form. The nucleation and growth of locally heated regions is modeled by a phenomenological treatment as well as a statistical model based on an exponential size distribution. The Mie-Grueneisen form of the EOS is one of many possible choices and is not a critical selection for implementing the model. In this report, model calculations are limited to proof-of-concept illustrations for shock loading. Results include (1) shock ignition and growth-to-detonation, (2) double shock ignition, and (3) quenching and reignition. A comparative study of Pop-plots is discussed based on the statistical model.
Y.Horie; Y.Hamate; D.Greening
Reactive thermal waves in energetic materials
Reactive thermal waves (RTWs) arise in several energetic material applications, including self-propagating high-temperature synthesis (SHS), high explosive cookoff, and the detonation of heterogeneous explosives. In this paper I exmaine ideal RTWs, by which I mean that (1) material motion is neglected, (2) the state dependence of reaction is Arrhenius in the temperature, and (3) the reaction rate is modulated by an arbitrary mass-fraction-based reaction progress function. Numerical simulations demonstrate that one's natural intuition, which is based mainly upon experience with inert materials and which leads one to expect diffusion processes to become relatively slow after a short time period, is invalid for high energy, state-sensitive reactive systems. Instead, theory predicts that RTWs can propagate at very high speeds. This result agrees with estimates for detonating heterogeneous explosives, which indicate that RTWs must spread from hot-spot nucleation sites at rates comparable to the detonation speed in order to produce experimentally-observed reaction zone thicknesses. Using dimensionless scaling and further invoking the high activation energy approximation, I obtain an analytic formula for the steady plane RTW speed from numerical calculations. I then compute the RTW speed for real explosives, and discuss aspects of their behavior.
Hill, Larry G [Los Alamos National Laboratory
This report describes work completed during the fifth quarter of a three year project to study the effects of mild chemical pretreatment on coal dissolution reactivity during low severity liquefaction or coal/oil coprocessing. The overall objective of this research is to elucidate changes in the chemical and physical structure of coal by pretreating with methanol or other simple organic solvent and a trace amount of hydrochloric acid and measure the influence of these changes on coal dissolution reactivity. Work this quarter focused on analytical characterization of untreated and treated Wyodak subbituminous coal and Illinois {number sign}6 bituminous coal. Mossbauer spectroscopy and x-ray diffraction techniques were used to study the effect of methanol/HCl pretreatment on the composition of each coal's inorganic phase. Results from these studies indicated that calcite is largely removed during pretreatment, but that other mineral species such as pyrite are unaffected. This finding is significant, since calcite removal appears to directly correlate with low severity liquefaction enhancement. Further work will be performed to study this phenomenon in more detail.
Knudsen Layer Reduction of Fusion Reactivity Kim Molvig and Nelson...
fusion cross section determine Gamow peak in the fusion reactivity. 2 Inertially confined fusion systems typically have plasma fuel enveloped by a cold non-reacting region or...
SP-19: Electrochemistry of Enargite: Reactivity in Alkaline Solutions
Actinide and xenon reactivity effects in ATW high flux systems
In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides.
Woosley, M.; Olson, K.; Henderson, D. L.; Sailor, W. C. [Department of Mechanical, Aerospace, and Nuclear Engineering University of Virginia, Charlottesville, Virginia 22903 (United States); Department of Nuclear Engineering and Engineering Physics University of Wisconsin, Madison, Wisconsin 53706-1687 (United States); Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
Chombo-Crunch: Advanced Simulation of Subsurface Flow and Reactive...
Chombo-Crunch: Advanced Simulation of Subsurface Flow and Reactive Transport Processes Associated with Carbon Sequestration PI Name: David Trebotich Institution: Lawrence Berkeley...
Finalized Phase 2-3 project work has field-proven two separate real-time reservoir processes that were co-developed via funding by the National Energy Technology Laboratory (NETL). Both technologies are presently patented in the United States and select foreign markets; a downhole-commingled reservoir stimulation procedure and a real-time tracer-logged fracturing diagnostic system. Phase 2 and early Phase 3 project work included the research, development and well testing of a U.S. patented gamma tracer fracturing diagnostic system. This stimulation logging process was successfully field-demonstrated; real-time tracer measurement of fracture height while fracturing was accomplished and proven technically possible. However, after the initial well tests, there were several licensing issues that developed between service providers that restricted and minimized Realtimezone's (RTZ) ability to field-test the real-time gamma diagnostic system as was originally outlined for this project. Said restrictions were encountered after when one major provider agreed to license their gamma logging tools to another. Both of these companies previously promised contributory support toward Realtimezone's DE-FC26-99FT40129 project work, however, actual support was less than desired when newly-licensed wireline gamma logging tools from one company were converted by the other from electric wireline into slickline, batter-powered ''memory'' tools for post-stimulation logging purposes. Unfortunately, the converted post-fracture measurement memory tools have no applications in experimentally monitoring real-time movement of tracers in the reservoir concurrent with the fracturing treatment. RTZ subsequently worked with other tracer gamma-logging tool companies for basic gamma logging services, but with lessened results due to lack of multiple-isotope detection capability. In addition to real-time logging system development and well testing, final Phase 2 and Phase 3 project work included the development of a real-time reservoir stimulation procedure, which was successfully field-demonstrated and is presently patented in the U.S. and select foreign countries, including Venezuela, Brazil and Canada. Said patents are co-owned by RTZ and the National Energy Technology Lab (NETL). In 2002, Realtimezone and the NETL licensed said patents to Halliburton Energy Services (HES). Additional licensing agreements (LA) are anticipated with other service industry companies in 2005. Final Phase 3 work has led to commercial applications of the real-time reservoir stimulation procedure. Four successfully downhole-mixed well tests were conducted with commercially expected production results. The most recent, fourth field test was a downhole-mixed stimulated well completed in June, 2004, which currently produces 11 BOPD with 90 barrels of water per day. Conducted Phase 2 and Phase 3 field-test work to date has resulted in the fine-tuning of a real-time enhanced stimulation system that will significantly increase future petroleum well recoveries in the United States and foreign petroleum fields, both onshore and offshore, and in vertical and horizontal wells.
George L. Scott III
Development of X-ray Tracer Diagnostics for Radiatively-Driven Copper-Doped Beryllium Ablators. NLUF FY1999 Report
This report covers the fiscal year 1999 portion of our ongoing project to develop tracer spectral diagnostics of ablator conditions in the hohlraum radiation environment. The overall goal of the experimental campaign is to measure the turn-on times of K{sub a} absorption features from tracers buried in planar witness plates. The tracers are thin and at a specific, known depth in the witness plates so that the turn-on times are indicators of the arrival of the Marshak wave at the specified depths. Ultimately, we intend to compare the delay in the turn-on times of the tracer signals between doped and undoped ablator materials, and thus study the effect of ablator dopants on the Marshak wave velocity. During FY 1999, our primary goal was to simply measure an absorption signal, matching tracer depth to drive temperature and testing the overall feasibility of our experimental scheme. In indirect-drive inertial confinement fusion (ICF) energy is deposited rapidly on the outside of a spherical capsule, ablating the outer layers of the capsule and compressing the interior. If this process is carefully controlled, then hydrogen fuel at the center of the capsule can be compressed and heated such that fusion reactions may proceed. The efficiency of the compression depends crucially on the time-dependent energy deposition onto the ablator material on the outside of the capsule. The nature of this coupling can be controlled through the use of ablator dopants, which modify the density and opacity of the ablator layer. Clearly, it is crucial to the success of indirect-drive ICF to have a means for testing the effects of ablator dopants, and more generally for having a diagnostic that is capable of determining time-dependent ablator properties. To this end, we are adapting tracer spectroscopy techniques to make time-dependent measurements of the ionization state of planar ablator materials mounted on the sides of hohlraums. Specifically, we are doing backlighter point-projection spectroscopy of K{sub a} features from tracers placed in the interiors of planar witness plates made of ablator materials. As the radiation wave, or Marshak wave, diffuses into the ablator material it drives a shock ahead of it. When the shock arrives at a given point in the witness plate it heats the tracer to roughly 20 eV. Soon after, the radiation wave arrives, heating the tracer to well above 100 eV nearly instantaneously. Thus, the ''turn-on'' of tracer absorption from high ionization states is an indicator that the radiation wave has arrived at the tracer. Furthermore, the time-dependent ionization balance in the tracer is, our simulations show, indicative of the efficiency with which the radiation field couples to the ablator material. Note that this technique holds out the possibility of making a determination of the instantaneous impact of the radiation field on the ablator physics, as opposed to something like a shock breakout measurement, in which the observed signal reflects the integrated time-history of the impact of the radiation field on the ablator.
Cohen, David H.; MacFarlane, Joseph J.; Wang, Ping; Jaanimagi, Paul A.; Oertel, John; Magelssen, Glenn; Landen, Otto L.; Back, Christina A.; Olson, Richard E.; Bailey, James E.
Two-tracer spectroscopy diagnostics of temperature profile in the conduction layer of a laser-ablated plastic foil
A technique that combines the diagnostics of electron temperature history and the measurements of ablation velocity with two-tracer x-ray spectroscopy has been developed for diagnosing the temperature profiles in the thermal conduction layers of laser-ablated plastic foils. The electron temperature in the plastic ablator was diagnosed using the isoelectronic line ratios of Al Ly{alpha} line to Mg Ly{alpha} line, emitted from a tracer layer of Al/Mg mixture buried under the ablator. The ablation velocity was inferred from the time delay between the onset time of x-ray line emissions from Al and Mg tracer layers buried at two depths in the ablator, respectively. From the measured electron temperatures and ablation velocity, the electron temperature profile in the conduction layer was inferred. The measured temperature profile was compared with the simulated one and reasonable agreement was found.
Zhang Jiyan; Yang Guohong; Hu Xin; Yang Jiamin; Ding Yaonan; Ding Yongkun; Zhang Baohan; Zheng Zhijian [Research Center of Laser Fusion, P. O. Box 919-986, Mianyang 621900 (China); Xu Yan; Yan Jun; Pei Wenbin [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)
Reactivity studies of antitumor active dirhodium compounds with DNA oligonucleotides
The study of the mechanism of action of an antitumor active drug is essential for improving the efficacy and reducing the side effects of the drug as well as for developing better alternatives. In this vein, reactions of dirhodium compounds with DNA oligonucleotides were investigated by the techniques of mass spectrometry, HPLC, and NMR spectroscopic analytical methods. The relative reactivities of three dirhodium compounds, namely Rh2(O2CCH3)4, Rh2(O2CCF3)4, and [Rh2(O2CCH3)2(CH3CN)6](BF4)2, with DNA oligonucleotides were studied and compared to the clinically used anticancer drugs cisplatin and carboplatin using both MALDI and ESI mass spectrometric methods. The compound Rh2(O2CCF3)4 exhibits the highest reactivity among the dirhodium compounds, which is comparable to cisplatin, followed by [Rh2(O2CCH3)2(CH3CN)6](BF4)2, and finally Rh2(O2CCH3)4 which is the least reactive. Various dirhodium-oligonucleotide adducts were detected with both MALDI and ESI methods, which involve substitution of different numbers of the original ligands of the given dirhodium compound. ESI MS was found to be a sufficiently soft ionization method for detecting intact metal adducts, and CID MS-MS was useful for detecting weakly bound species such as axial adducts [M+Rh2(O2CCH3)4] and for comparing the relative bond strength between ligands in the metal adduct. A combination of anion exchange HPLC purification and enzymatic digestion studies of the adducts of Rh2(O2CCH3)4 with the 5'-CCTTCAACTCTC oligonucleotide revealed that Rh2(O2CCH3)4 binds to the center or to the ends of the oligonucleotide sequence by displacement of one or two acetate groups. Kinetic products of the type [M+Rh2(O2CCH3)3] obtained from the reaction of Rh2(O2CCH3)4 with 5'-CTCTCAACTTCC were separated by employing both reverse phase and anion exchange HPLC methods. The adduct that involves binding of the dirhodium unit to the exocyclic N4 atom of C5 and the N7 of A6 was found to be most stable whereas other adducts involving binding of C3 or C12 residues are clearly less stable. Reaction of cis-[Rh2(DAP)(O2CCH3)3(CH3OH)](O2CCH3) (DAP = 1,12- diazaperylene) with 5'-CTCTCAACTTCC produced a major adduct in which DAP group intercalates between 6A and 7A in the double stranded adduct with the rhodium atom that is not coordinated to the DAP group forming a covalent bond to the N7 atom of 6A which lends stability to the adduct.
Kang, Mijeong
Instrumentation @ Catalysis: Reactivity and Structure Group | Chemistry
Instrumentation Instrumentation The Catalysis Group at BNL is leading research initiatives into the development of new tools and techniques that focus on the characterization of heterogeneous catalytic reactions and catalysts using imaging, spectroscopy and scattering techniques and integrated combinations of them under reaction conditions to unravel the morphology, chemical and structural properties, of catalysts, respectively. These efforts revolve around the use of synchrotron radiation (NSLS), electrons (CFN) and quantum tunneling tools with particular thrusts into imaging, spectroscopy and scattering. Groups Instrumentation(BNL) Three UHV chambers with diverse instrumentation for surface characterization: LEED, UPS, XPS, AES, TPD, ISS, PM-AP-IRRAS, Reactivity Cell. All the systems include ancillary instrumentation such as sputtering guns and metal evaporators. The IRRAS system was retrofitted with an ambient pressure (AP) cell on top of the UHV system. The sample can be prepared and characterized in UHV and then transfer in vacuum to the AP cell.
doi:10.1155/2011/839682 Review Article Haptenation: Chemical Reactivity and Protein Binding
Copyright � 2011 Itai Chipinda et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Low molecular weight chemical (LMW) allergens are commonly referred to as haptens. Haptens must complex with proteins to be recognized by the immune system. The majority of occupationally related haptens are reactive, electrophilic chemicals, or are metabolized to reactive metabolites that form covalent bonds with nucleophilic centers on proteins. Nonelectrophilic protein binding may occur through disulfide exchange, coordinate covalent binding onto metal ions on metalloproteins or of metal allergens, themselves, to the major histocompatibility complex. Recent chemical reactivity kinetic studies suggest that the rate of protein binding is a major determinant of allergenic potency; however, electrophilic strength does not seem to predict the ability of a hapten to skew the response between Th1 and Th2. Modern proteomic mass spectrometry methods that allow detailed delineation of potential differences in protein binding sites may be valuable in predicting if a chemical will stimulate an immediate or delayed hypersensitivity. Chemical aspects related to both reactivity and protein-specific binding are discussed. 1.
Itai Chipinda; Justin M. Hettick; Paul D. Siegel
The Post-Shock Chemical Lifetimes of Outflow Tracers and a Possible New Mechanism to Produce Water Ice Mantles
We have used a coupled time-dependent chemical and dynamical model to investigate the lifetime of the chemical legacy left in the wake of C-type shocks. We concentrate this study on the chemistry of H2O and O2, two molecules which are predicted to have abundances that are significantly affected in shock-heated gas. Two models are presented: (1) a three-stage model of pre-shock, shocked, and post-shock gas; and (2) a Monte-Carlo cloud simulation where we explore the effects of stochastic shock activity on molecular gas over a cloud lifetime. In agreement with previous studies, we find that shock velocities in excess of 10 km s^-1 are required to convert all of the oxygen not locked in CO into H2O before the gas has an opportunity to cool. For pure gas-phase models the lifetime of the high water abundances, or ``H2O legacy'', in the post-shock gas is 4 - 7 x 10^5 years. Through the Monte Carlo cloud simulation we demonstrate that the time-average abundance of H2O is a sensitive function of the frequency of shocks. Thus we predict that the abundance of H2O and other known outflow tracers can be used to trace the history of shock activity in molecular gas. For gas-grain models we find that the abundance of water-ice on grain surfaces can be quite large and is comparable to that observed in molecular clouds. This offers a possible alternative method to create water mantles without resorting to grain surface chemistry: gas heating and chemical modification due to a C-type shock and subsequent depletion of the gas-phase species onto grain mantles.
Edwin A. Bergin; Gary J. Melnick; David A. Neufeld
Artificial bee colony algorithm solution for optimal reactive power flow
Artificial bee colony (ABC) algorithm is an optimization algorithm based on the intelligent foraging behavior of honeybee swarm. Optimal reactive power flow (ORPF) based on ABC algorithm to minimize active power loss in power systems is studied in this ... Keywords: Artificial bee colony, Optimal reactive power flow, Penalty function, Power system
K�r?at Ayan; Ula? K?l?�
1 MARKETS FOR REACTIVE POWER AND RELIABILITY: A WHITE PAPER Engineering and Economics as efficient and optimal production and prices for real and reactive power. The purpose of this paper delivery of electric power. To accomplish this end, the paper opens with specification of an economic
Differential evolution approach for optimal reactive power dispatch
Differential evolution based optimal reactive power dispatch for real power loss minimization in power system is presented in this paper. The proposed methodology determines control variable settings such as generator terminal voltages, tap positions ... Keywords: Differential evolution, Loss minimization, Optimal power flow, Penalty function, Reactive power dispatch
M. Varadarajan; K. S. Swarup
Reactive Power Compensation Technologies, State-of-the-Art Review
reactors to provide or absorb the required reactive power have been developed [7], [8], [9]. Also, the use static VAR generators, using power electronic technologies have been proposed and developed [7 compensators (SVC) consist of standard reactive power shunt elements (reactors and capacitors) which
Rudnick, Hugh
Etching radical controlled gas chopped deep reactive ion etching
A method for silicon micromachining techniques based on high aspect ratio reactive ion etching with gas chopping has been developed capable of producing essentially scallop-free, smooth, sidewall surfaces. The method uses precisely controlled, alternated (or chopped) gas flow of the etching and deposition gas precursors to produce a controllable sidewall passivation capable of high anisotropy. The dynamic control of sidewall passivation is achieved by carefully controlling fluorine radical presence with moderator gasses, such as CH.sub.4 and controlling the passivation rate and stoichiometry using a CF.sub.2 source. In this manner, sidewall polymer deposition thicknesses are very well controlled, reducing sidewall ripples to very small levels. By combining inductively coupled plasmas with controlled fluorocarbon chemistry, good control of vertical structures with very low sidewall roughness may be produced. Results show silicon features with an aspect ratio of 20:1 for 10 nm features with applicability to nano-applications in the sub-50 nm regime. By comparison, previous traditional gas chopping techniques have produced rippled or scalloped sidewalls in a range of 50 to 100 nm roughness.
Olynick, Deidre; Rangelow, Ivo; Chao, Weilun
Variational reactivity estimates: new analyses and new results
A modified form of the variational estimate of the reactivity worth ofa perturbation was previously developed to extend the range of applicability of variational perturbation theory for perturbations leading to negative reactivity worths. Recent numerical results challenged the assumptions behind the modified form. In this paper, more results are obtained, leading to the conclusion that sometimes the modified form extends the range ofapplicability of variational perturbation theory for positive reactivity worths as well, and sometimes the standard variational form is more accurate for negative-reactivity perturbations. In addition, this paper proves that using the exact generalized adjoint function would lead to an inaccurate variational reactivity estimate when the error in the first-order estimate is large; the standard generalized adjoint function, an approximation to the exact one, leads to Lore accurate results. This conclusion is also demonstrated numerically. Transport calculations use the PARTISN multi group discrete ordinates code
Favorite, Jeffrey A [Los Alamos National Laboratory
Motorola's Exhaust Optimization Program: Tracer Gas Application for Gas Panel Enclosures
The Motorola Exhaust Optimization Program strives toward identifying the optimum exhaust requirements for gas panel enclosures to help conserve energy and provide future exhaust capacity for new tools. Various Motorola studies have shown that at least 20% of total fab electrical usage is attributed to make-up air fans, exhaust fans, and chilled water systems for recirculation and make-up air. This is equivalent to over 35 million kWh per a year for a typical Motorola Semiconductor Products Sector (SPS) fab. These obtained studies have prompted Motorola to focus on a broad range of energy conservation projects. This paper will focus on exhaust optimization through tracer gas testing.
Testing has resulted in exhaust and make-up air reductions of as high as 70% of manufacturer's specifications per gas enclosure. This approach leads to energy conservation and infrastructure cost avoidance for new exhaust fans, ductwork, abatement equipment, and make-up air systems.
Myart, H. R.; Camacho, R.
Nitrogen geochemistry as a tracer of fluid flow in a hydrothermal vent complex in the Karoo Basin, South Africa
Nitrogen geochemistry as a tracer of fluid flow in a hydrothermal vent complex in the Karoo Basin and hydrothermal vent complexes (HVC) in the Karoo Basin in South Africa. The HVC formed during phreatic eruptions from the lower stratigraphic units of the Karoo Basin shows that the vitrinite reflectance and d15 N
Svensen, Henrik
Environmental assessment of the use of radionuclides as tracers in the enhanced recovery of oil and gas. Final report
An environmental assessment of the use of radioisotopes as interwell tracers in field flooding for the enhanced recovery of oil and natural gas was performed. A typical operation using radioisotopes for interwell tracing was analyzed from the standpoint of three stages of operation: aboveground, subsurface, and recovery and disposal. Doses to workers who handle radioactive tracers and to members of the public were estimated for normal and accidental exposure scenarios. On the basis of estimates of the total quantity of tracer radionuclides injected in a year, the annual number of projects, the average number of injections per project, and assumed values of accident frequency, the collective dose equivalent is estimated to be 1.1 man-rem/y to workers and 15 man-rem/y to members of the public. The national radiological impact of the use of radioisotopes as interwell tracers in EOR projects is estimated to be a total collective dose equivalent of <16 man-rem/y. Accidential exposures are estimated to contribute relatively little to the total. 47 references, 8 figures, 43 tables.
Ng, Y.C.; Cederwall, R.T.; Anspaugh, L.R.
An SF6 Tracer Study of the Flow Dynamics in the Stockton Deep Water Ship Channel: Implications
by determining the net velocity, the dispersion coefficient, and gas exchange rates from changes in tracer is the dispersion coefficient, and l is the first order loss rate for processes such as gas exchange. In order to all loses such as advection, dispersion, and gas exchange (Fig. 9). This translated into a PRT of 7
Ho, David
Assessing Tracer Transport Algorithms and the Impact of Vertical Resolution in a Finite-Volume Dynamical Core
Modeling the transport of trace gases is an essential part of any atmospheric model. The tracer transport scheme in the Community Atmosphere Model finite-volume dynamical core (CAM-FV), which is part of the National Center for Atmospheric Research�...
James Kent; Christiane Jablonowski; Jared P. Whitehead; Richard B. Rood
Early maturation processes in coal. Part 2: Reactive dynamics simulations using the ReaxFF reactive force field on Morwell Brown coal structures
Early maturation processes in coal. Part 2: Reactive dynamics simulations using the ReaxFF reactive force field on Morwell Brown coal structures Elodie Salmon a , Adri C.T. van Duin b , François Lorant Brown coal using the ReaxFF reactive force field. We find that these reactive MD simulations
Goddard III, William A.
We have investigated the reaction of room-temperature silane and disilane on a hot polycrystalline silicon surface using both a collision-free molecular beam and a very low pressure CVD cell. Reactive sticking coefficients were obtained from deposition rate data over a wide range of temperatures and silane (disilane) fluxes. The RSCs are substantially less than one, ranging from 6 x 10/sup -5/ to 4 x 10/sup -2/. For silane we observed curved Arrhenius plots with slopes decreasing from approx.60 kcal mol/sup -1/ at low temperatures to approx.2 kcal mol/sup -1/ at higher temperatures. The RSCs are independent of flux (pressure) at 1040/sup 0/C, but vary as flux to the approx.-1/2 power at 710/sup 0/C. A model comprised of a dissociative adsorption mechanism with competing associative desorption and reaction was found to give reasonable agreement. For disilane, we observed RSCs that were roughly ten times higher than those for silane. We also observed a curved Arrhenius plot and a flux dependence at 710/sup 0/C for disilane. 22 refs., 5 figs.
Reactivity of coals under coprocessing conditions
In the recent years greater interest has developed for processes involving coal and petroleum fractions to produce distillate fuels. Coprocessing is especially attractive as a direct liquefaction process because it involves the use of heavy petroleum fractions, so both coal and heavy petroleum resids are upgraded simultaneously. The main distinction of coprocessing from other direct liquefaction processes is that coprocessing is more complex from a chemical standpoint than direct liquefaction processes which use traditional solvents, due to the greater variety of hydrocarbons (aromatic from the coal and aliphatics from the petroleum) present in the system. Therefore, need arises for better understanding of the chemical and physical interactions during coprocessing. The aim of the present study is to examine the influence of reaction conditions, coal and petroleum resid properties as well as the compatibility of the coal/petroleum resid pairs in terms of structural components on total coal conversion. Special focus will be given to the reactivity of coals and interaction of the coal and resid which lead to anisotropic coke.
Tomic, J.; Schobert, H.H.
Rate-limited U(VI) desorption during a small-scale tracer test in a hetereogeneous uranium contaminated aquifer
reactive transport modeling of uranium bioremediation fieldof calcium on aqueous uranium(VI) speciation and adsorptiontransport modeling of a uranium bioremediation field
Fox, P.M.
Development of reactivity feedback effect measurement techniques under sub-critical condition in fast reactors
The first-of-a-kind reactor has been licensed by a safety examination of the plant design based on the measured data in precedent mock-up experiments. The validity of the safety design can be confirmed without a mock-up experiment, if the reactor feed-back characteristics can be measured before operation, with the constructed reactor itself. The 'Synthesis Method', a systematic and sophisticated method of sub-criticality measurement, is proposed in this work to ensure the safety margin before operation. The 'Synthesis Method' is based on the modified source multiplication method (MSM) combined with the noise analysis method to measure the reference sub-criticality level for MSM. A numerical simulation for the control-rod reactivity worth and the isothermal feed-back reactivity was conducted for typical fast reactors of 100 MWe-size, 300 MWe-size, 750 MWe-size, and 1500 MWe-size to investigate the applicability of Synthesis Method. The number of neutron detectors and their positions necessary for the measurement were investigated for both methods of MSM and the noise analysis by a series of parametric survey calculations. As a result, it was suggested that a neutron detector located above the core center and three or more neutron detectors located above the radial blanket region enable the measurement of sub-criticality within 10% uncertainty from -$0.5 to -$2 and within 15% uncertainty for the deeper sub-criticality. (authors)
Kitano, A.; Nishi, H. [Japan Atomic Energy Agency, 1 1, Shiraki, Tsuruga-shi, Fukui-ken, 919-1279 (Japan); Suzuki, T. [Japan Atomic Energy Agency, 2-4, Shirakata-Shirane, Tokai-mura, Naka-gun, Ibaraki-ken, 319-1195 (Japan); Okajima, S.; Kanemoto, S. [Univ. of Aizu, Tsuruga, Ikki-machi, Aizu-Wakamatsu-shi, Fukushima-ken, 965-8580 (Japan)
Reactivity Control Schemes for Fast Spectrum Space Nuclear Reactors
Several different reactivity control schemes are considered for future space nuclear reactor power systems. Each of these control schemes uses a combination of boron carbide absorbers and/or beryllium oxide reflectors to achieve sufficient reactivity swing to keep the reactor subcritical during launch and to provide sufficient excess reactivity to operate the reactor over its expected 7�15 year lifetime. The size and shape of the control system directly impacts the size and mass of the space reactor's reflector and shadow shield
Aaron E. Craft; Jeffrey C. King
Gas atomization reaction synthesis was employed as a simplified method for processing oxide dispersion forming precursor Fe-based powders (e.g., Fe�Cr�Y�Hf). During this process a reactive atomization gas (i.e., Ar�O2) was used to oxidize the powder surfaces during primary break-up and rapid solidification of the molten alloy. This resulted in envelopment of the powders by an ultra-thin (t < 50 nm) metastable Cr-enriched oxide shell that was used as a vehicle to transport oxygen into the consolidated microstructure. Subsequent elevated temperature heat treatment promoted thermodynamically driven oxygen exchange reactions between trapped films of Cr-enriched oxide and internal (Y, Hf)-enriched intermetallic precipitates, resulting in highly stable nano-metric mixed oxide dispersoids (i.e., Y�Hf�O) that were identified with X-ray diffraction. Transmission electron microscopy and atom probe tomography results also revealed that the size and distribution of the dispersoids were found to depend strongly on the original rapidly solidified microstructure. To exploit this, several oxide dispersion strengthened microstructures were engineered from different powder particle size ranges, illustrating microstructural control as a function of particle solidification rate. Additionally, preliminary thermal�mechanical processing was used to develop a fine scale dislocation substructure for ultimate strengthening of the alloy.
Rieken, Joel R [Ames Laboratory; Anderson, Iver E [Ames Laboratory; Kramer, Matthew J [Ames Laboratory; Odette, G R [University of California; Stergar, E [University of California; Haney, E [University of California
On-line reactive power compensation schemes for unbalanced three phase four wire distribution feeders
A new reactive power compensation method is developed to reduce the negative and zero sequence components of load currents and to improve the load bus power factor of unbalanced three-phase four-wire distribution feeders. Negative and zero sequences currents may cause additional losses and damages to power systems. Load compensation at the load bus is an effective method to eliminate those undesired sequence currents. The compensation technique uses a Y-connected and a [Delta]-connected static reactive power compensators to give a different amount of reactive power compensation to each phase. The compensation formulas are very suitable for on-line control by measuring phase voltages and currents in the real time. The compensation effect can also be achieved even if one leg of the SVCs is out of service. In addition to balancing effect and power factor improvement at the load bus, the SVCs can also be used to support the load bus voltage and to maintain the substation feeder at unity powder factor. Digital simulations are made with the load data measured from an 11.4kV secondary substation feeder.
Sanyi Lee; Chijui Wu (National Taiwan Inst. of Tech., Taipei (Taiwan, Province of China). Dept. of Electrical Engineering)
cells. PRBs can be installed using several methods including trenching or through injection wells. Treatability studies are typically conducted to evaluate the performance...
Reactivity estimation and validation for the control of reactor neutronic power. Master's thesis
From July 1986 to July 1991, a joint MIT-SNL research team developed a controller capable of safely raising reactor power by approximately five orders of magnitude in a few seconds. This controller was experimentally demonstrated on the MIT Research Reactor (MITR-II) as well as on the 'Sandia National Laboratories' Annular Core Research Reactor (ACRR). This controller's intended application is for the control of spacecraft nuclear reactors. However, it also has direct application for the control of military, commercial, and research reactors. This report is concerned with a method for enhancing the controller's performance through the development of an improved model to validate estimates of the magnitude of reactivity feedback effects. The focus is on the Doppler effect but the resulting model is applicable to other types of reactivity feedback such as that associated with the thermal effects of a hydrogen coolant.
Lasota, C.S.
Enhanced durability and reactivity for zinc ferrite desulfurization sorbent. Volume 1, Bench-scale testing and analysis
AMAX Research & Development Center (AMAX R&D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.
Assessment of the Economic Potential of Microgrids for Reactive Power Supply
of Commercial Building Microgrids,� IEEE Transactions onEconomic Potential of Microgrids for Reactive Power Supplyof creating an incentive for microgrids to provide reactive
Appen, Jan von
Synthesis of Sm-Fe-N Hard Magnets by Reactive Mechanical Milling
In this study, we have performed reactive mechanical milling on Sm2Fe17 alloy under hydrogen atmosphere. After reactive mechanical milling, the Sm2Fe17�...
Method of detecting leakage from geologic formations used to sequester CO.sub.2
The invention provides methods for the measurement of carbon dioxide leakage from sequestration reservoirs. Tracer moieties are injected along with carbon dioxide into geological formations. Leakage is monitored by gas chromatographic analyses of absorbents. The invention also provides a process for the early leak detection of possible carbon dioxide leakage from sequestration reservoirs by measuring methane (CH.sub.4), ethane (C.sub.2H.sub.6), propane (C.sub.3H.sub.8), and/or radon (Rn) leakage rates from the reservoirs. The invention further provides a method for branding sequestered carbon dioxide using perfluorcarbon tracers (PFTs) to show ownership.
White, Curt (Pittsburgh, PA); Wells, Arthur (Bridgeville, PA); Diehl, J. Rodney (Pittsburgh, PA); Strazisar, Brian (Venetia, PA)
Using CO2 Lidar for Standoff Detection of a Perfluorocarbon Tracer in Air
The Tag, Track and Location System Program (TTL) is investigating the use of PFTs as tracers for tagging and tracking items of interest or fallen soldiers. In order for the tagging and tracking to be valuable there must be a location system that can detect the PFTs. This report details the development of an infrared lidar platform for standoff detection of PFTs released into the air from a tagged object or person. Furthering work performed using a table top lidar system in an indoor environment; a mobile mini lidar platform was assembled using an existing Raman lidar platform, a grating tunable CO{sub 2} IR laser, Judson HgCdTe detector and miscellaneous folding optics and electronics. The lidar achieved {approx}200 ppb-m sensitivity in laboratory and indoor testing and was then successfully demonstrated at an outdoor test. The lidar system was able to detect PFTs released into a vehicle from a distance of 100 meters. In its final, fully optimized configuration the lidar was capable of repeatedly detecting PFTs in the air released from tagged vehicles. Responses were immediate and clear. This report details the results of a proof-of-concept demonstration for standoff detection of a perfluorocarbon tracer (PFT) using infrared lidar. The project is part of the Tag, Track and Location System Program and was performed under a contract with Tracer Detection Technology Corp. with funding from the Office of Naval Research. A lidar capable of detecting PFT releases at distance was assembled by modifying an existing Raman lidar platform by incorporating a grating tunable CO{sub 2} IR laser, Judson HgCdTe detector and miscellaneous folding optics and electronics. The lidar achieved {approx}200 ppb-m sensitivity in laboratory and indoor testing and was successfully demonstrated at an outdoor test. The demonstration test (scripted by the sponsor) consisted of three parked cars, two of which were tagged with the PFT. The cars were located 70 (closest) to 100 meters (farthest) from the lidar (the lidar beam path was limited by site constraints and was {approx}100 meters). When one door of each of the cars was opened (sequentially), the lidar was clearly able to determine which vehicles had been tagged and which one was not. The lidar is probably capable of greater than 0.5 kilometer standoff distances based on the extreme amount of signal return achieved (so much that the system had to be de-tuned). The BNL lidar system, while optimized to the extent possible with available parts and budget, was not as sensitive as it could be. Steps to improve the lidar are detailed in this report and include using a better laser system (for more stable power output), dual wavelengths (to improve the sensitivity and allow common mode noise reduction and to allow the use of the lidar in a scanning configuration), heterodyning (for range resolved PFT detection) and an off-axis optical configuration (for improved near field sensitivity).
Heiser,J.H.; Smith, S.; Sedlacek, A.
Photo of the Week: Reactive Ion Etching | Department of Energy
Reactive Ion Etching Reactive Ion Etching Photo of the Week: Reactive Ion Etching October 17, 2013 - 1:26pm Addthis Have you ever heard of Laue lenses? These multilayer lenses are used to focus high-intensity x-ray beams to show the details of nano material structures. In this photo, the drop-like domes were carved through a process called reactive ion etching, which produced the striped bubbles you see in the Laue lens. The prototype in this image helped scientists perfect the process of creating lenses so precise that scientists are able to focus x-rays to within a single nanometer. | Photo courtesy of Brookhaven National Laboratory. Have you ever heard of Laue lenses? These multilayer lenses are used to focus high-intensity x-ray beams to show the details of nano material
A-26: Nanoindentation Investigation of the Reactive Pulsed Laser ...
... of the Reactive Pulsed Laser Deposited Superconducting Niobium Nitride Thin Films. Author(s) ... A-33: Modeling of a Displacive Transformation within Continuous ... Dye-Sensitized Solar Cells by Introducing a TiN Nanocrystalline Thin Film.
Pre-plated reactive diffusion-bonded battery electrode plaques
A high strength, metallic fiber battery plaque is made using reactive diffusion bonding techniques, where a substantial amount of the fibers are bonded together by an iron-nickel alloy.
Maskalick, Nicholas J. (Pittsburgh, PA)
Land Use and Reactive Nitrogen Discharge: Effects of Dietary Choices
Modern agriculture alters natural biological and geophysical processes, with magnitudes proportional to its spatial extent. Cultivation is also the main cause of artificially enhanced reactive nitrogen (Nr) availability in natural ecosystems. ...
Gidon Eshel; Pamela A. Martin; Esther E. Bowen
Radiation Chemistry of Ionic Liquids: Reactivity of Primary Species
Liquids: Reactivity of Primary Species Liquids: Reactivity of Primary Species James F. Wishart In "Ionic Liquids as Green Solvents: Progress and Prospects" Rogers, R. D. and Seddon, K. R. , Eds.; ACS Symp. Ser. 856, Ch. 31, pp. 381-395, American Chemical Society, Washington, DC, 2003. (ISBN 0-84123-856-1) [Information about the book] Abstract: An understanding of the radiation chemistry of ionic liquids is important for development of their applications in radioactive material processing and for the application of pulse radiolysis techniques to the general study of chemical reactivity in ionic liquids. The distribution of primary radiolytic species and their reactivities determine the yields of ultimate products and the radiation stability of a particular ionic liquid. This chapter introduces some principles of radiation chemistry and the
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
Modeling the reactive inorganic solute distributions in the groundwater flow systems of the Hanford Site using inverse analytical modeling techniques
Inverse analytical techniques were used to model solute distributions and determine transport parameters for two flow systems in the Yakima Basalt subgroup at the Hanford Site in Washington state. Previous studies of these flow systems used chloride as a tracer to determine the transverse dispersivities of several of the Hanford flow systems. This study analyzes three reactive solute distributions, two of which are coincident, to determine aquifer and solute reactions parameters. In addition to modeling the transport of two solutes, a chemical speciation model, MINTEQA2, was used to determine saturation indices for the sample waters in an effort to verify observed secondary mineralization. Boron and potassium were the two solute distributions modeled in this study. The analytical model results accurately reproduce the observed field conditions, comply with the assumptions of the conceptual model, and match the results of the previous chloride study. The parameters determined by the analytical model include the source size and dimension, transverse dispersivity, and reaction rate/solute velocity ratio. The reaction rate term is used to describe the first order reactions experienced by boron and potassium. This term is believed to represent the affect of both precipitation and non-equilibrium sorption reactions. Due to the nature of the problem, this ratio cannot be separated for its individual terms. However, the relative rates of reaction for the solutes are determined.
Adamski, Mark Robert
Reactive Reserve Requirements and Optimal Allocation Among Resources
Voltage stability is a major concern in power system operation, and the need to maintain it limits power transfers in the prevailing open access environment. In a power system with significant induction motor loads, voltage instability can be manifested either in the form of delayed voltage recovery or voltage collapse. Inadequate reactive supply is a major factor in causing these problems. Reactive supply is an important ingredient in maintaining healthy power system voltages and facilitating power tran...
(Electronic structure and reactivities of transition metal clusters)
The following are reported: theoretical calculations (configuration interaction, relativistic effective core potentials, polyatomics, CASSCF); proposed theoretical studies (clusters of Cu, Ag, Au, Ni, Pt, Pd, Rh, Ir, Os, Ru; transition metal cluster ions; transition metal carbide clusters; bimetallic mixed transition metal clusters); reactivity studies on transition metal clusters (reactivity with H{sub 2}, C{sub 2}H{sub 4}, hydrocarbons; NO and CO chemisorption on surfaces). Computer facilities and codes to be used, are described. 192 refs, 13 figs.
[Electronic structure and reactivities of transition metal clusters
Distributed measurements of tracer response on packed bed flows using a fiberoptic probe array. Final report
Scale-up of packed bed processes, particularly those involving chromatographic separations, is made difficult by a seemingly inevitable increase in dispersion due to packing nonuniformity. To provide a suitable characterization, the authors measured the spatial distribution of dispersion and mixing in packed beds of uniform impervious spherical glass particles by a tracer impulse technique. The key feature in this work is the use of a fiberoptic array at the exit plane to obtain a time-resolved spatially distributed response. All experiments were in the creeping flow regime. The authors used a fluorescent dye with laser excitation through the fiber terminations in the bed. The fluoresced radiation was collected through the same fibers. They analyzed the data by the use of indices of the extent of micromixing based on Danckwerts`s original degree of segregation and an additional index of structural uniformity. The computations involve a moment analysis of the individual and average probe responses. A simple model gives expressions for the indices in terms of the Peclet number and is shown to provide a useful limiting case. The computed indices are also shown to be very sensitive to adsorption of dye on the surface of the glass. However, for some of the experiments with the largest spheres using Pyrex glass, the effects of adsorption are indiscernible. This technique successfully separates the contribution of micromixed fluid to overall bed dispersion from the contribution due to the transverse variation of the flow residence time.
Jones, M.C.; Nassimbene, R.; Wolfe, J. [National Inst. of Standards and Technology, Boulder, CO (United States). Chemical Science and Technology Lab.; Frederick, N. [Rocky Mountain Electron Video, Boulder, CO (United States)
Development of a tracer test in a flooded uranium mine using Lycopodium clavatum
ABSTRACT: The polymetallic Niederschlema/Alberoda uranium deposit in the Saxonian Erzgebirge (Ore Mountains) has been flooded since 1991. The objectives of the tests were to investigate the quality and rate of flow within a large part of the flooded mine to predict the mass flow of the pollutants. Based on the results of a first tracer test with Lycopodium clavatum in mid 1992 a second one was conducted at the end of 1995. Four insertion and two sampling points were chosen and at each sampling point up to 800 g of coloured spores were inserted by using a newly developed insertion apparatus: LydiA (Lycopodium Apparatus). Beginning one day after insertion, at each sampling point two samples per weekday were taken. Out of the 15 samples an aliquot amount of material was counted and resulted in a reasonable good recovery rate of 2 %. It could be shown, that the mean speed of the mine water within the investigated part of the mine ranges between 3 and 8 m min-1 and that the different parts of the mine are hydraulically well connected with each other. Therefore it may be that the pollutants within the flooded mine are transported by convective flow resulting in an exchange from deeper parts of the mine into higher ones. 1
Christian Wolkersdorfer; Irena Trebu�ak; Nicole Feldtner
Simulations of greenhouse trace gases using the Los Alamos chemical tracer model
Through three-dimensional global model studies on atmospheric composition and transport, we are improving our quantitative understanding of the origins and behavior of trace gases that affect Earth's radiative energy balance and climate. We will focus, in this paper, on the simulations of three individual trace gases including CFC-11, methyl chloroform, and methane. We first used our chemical tracer model to study the global distribution and trend of chemically inert CFC-11 observed by the Atmospheric Lifetime Experiment. The results show that the model has the ability to reproduce the time-series of the observations. The purpose of this CFC-11 simulation was to test the transport of the model. We then used to model introduce methyl chloroform into the atmosphere according to the known emission patterns and iteratively varied OH fields so that the observed concentrations of methyl chloroform from the observations could be simulated well. The rationale behind this approach is that the reaction with OH is the dominant sink for metyl chloroform and the transport of the model has been tested in the previous CFC-11 study. Finally, using the inferred OH distributions, we conducted a steady-state simulation to reproduce the current methane distribution. The general agreement between the modeled an observed methane surface concentrations has laid a foundation for the simulation of the transient increase of methane.
Kao, C.Y.J.; Morz, E. (Los Alamos National Lab., NM (United States)); Tie, X. (Scripps Institution of Oceanography, San Diego, CA (United States))
Through three-dimensional global model studies on atmospheric composition and transport, we are improving our quantitative understanding of the origins and behavior of trace gases that affect Earth`s radiative energy balance and climate. We will focus, in this paper, on the simulations of three individual trace gases including CFC-11, methyl chloroform, and methane. We first used our chemical tracer model to study the global distribution and trend of chemically inert CFC-11 observed by the Atmospheric Lifetime Experiment. The results show that the model has the ability to reproduce the time-series of the observations. The purpose of this CFC-11 simulation was to test the transport of the model. We then used to model introduce methyl chloroform into the atmosphere according to the known emission patterns and iteratively varied OH fields so that the observed concentrations of methyl chloroform from the observations could be simulated well. The rationale behind this approach is that the reaction with OH is the dominant sink for metyl chloroform and the transport of the model has been tested in the previous CFC-11 study. Finally, using the inferred OH distributions, we conducted a steady-state simulation to reproduce the current methane distribution. The general agreement between the modeled an observed methane surface concentrations has laid a foundation for the simulation of the transient increase of methane.
Kao, C.Y.J.; Morz, E. [Los Alamos National Lab., NM (United States); Tie, X. [Scripps Institution of Oceanography, San Diego, CA (United States)
The focus of this program was the characterization of the soils beneath the main air ducts connecting the exhaust plenums with the Fan House. The air plenums experienced water intrusion during BGRR operations and after shutdown. The water intrusions were attributed to rainwater leaks into degraded parts of the system and to internal cooling water system leaks. As part of the overall characterization efforts, a state-of-the-art gaseous perfluorocarbon tracer technology was utilized to characterize leak pathways from the ducts. This in turn suggests what soil regions under or adjacent to the ductwork should be emphasized in the characterization process. Knowledge of where gaseous tracers leak from the ducts yields a conservative picture of where water transport, out of or into, the ducts might have occurred.
Preliminary Interpretation of a Radionuclide and Colloid Tracer Test in a Granodiorite Shear Zone at the Grimsel Test Site, Switzerland
In February and March 2012, a tracer test involving the injection of a radionuclide-colloid cocktail was conducted in the MI shear zone at the Grimsel Test Site, Switzerland, as part of the Colloids Formation and Migration (CFM) project. The colloids were derived from FEBEX bentonite, which is mined in Spain and is being considered as a potential waste package backfill in a Spanish nuclear waste repository. The tracer test, designated test 12-02 (second test in 2012), involved the injection of the tracer cocktail into borehole CFM 06.002i2 and extraction from the Pinkel surface packer at the main access tunnel wall approximately 6.1 m from the injection interval. The test configuration is depicted in Figure 1. This configuration has been used in several conservative tracer tests and two colloid-homologue tracer tests since 2007, and it is will be employed in an upcoming test involving the emplacement of a radionuclide-doped bentonite plug into CFM 06.002i2 to evaluate the swelling and erosion of the bentonite and the transport of bentonite colloids and radionuclides from the source to the extraction point at the tunnel wall. Interpretive analyses of several of the previous tracer tests, from 09-01 through 12-02 were provided in two previous Used Fuel Disposition Program milestone reports (Arnold et al., 2011; Kersting et al., 2012). However, only the data for the conservative tracer Amino-G Acid was previously analyzed from test 12-02 because the other tracer data from this test were not available at the time. This report documents the first attempt to quantitatively analyze the radionuclide and colloid breakthrough curves from CFM test 12-02. This report was originally intended to also include an experimental assessment of colloid-facilitated transport of uranium by bentonite colloids in the Grimsel system, but this assessment was not conducted because it was reported by German collaborators at the Karlsruhe Institute of Technology (KIT) that neither uranium nor neptunium adsorbed appreciably to FEBEX bentonite colloids in Grimsel groundwater (Huber et al., 2011). The Grimsel groundwater has a relatively high pH of {approx}9, so the lack of uranium and neptunium adsorption to clay is not surprising given the tendency for these actinides to form very stable negative or neutrally-charged uranyl- or calcium-uranyl-carbonate complexes at these pH, particularly in a water that is effectively saturated with respect to calcite. It was also observed in testing conducted at LANL earlier in 2012 that uranium did not adsorb measurably to Grimsel granodiorite in a synthetic Grimsel groundwater at pH {approx}8.5 (Kersting et al., 2012). Thus, the planned experimental work was not pursued because all the available information clearly pointed to an expected result that uranium transport would not be facilitated by clay colloids in the Grimsel system.