Sample records for non-isothermal multiphase reactive

  1. Modeling non-isothermal multiphase multi-species reactive chemical transport in geologic media

    SciTech Connect (OSTI)

    Tianfu Xu; Gerard, F.; Pruess, K.; Brimhall, G.

    1997-07-01T23:59:59.000Z

    The assessment of mineral deposits, the analysis of hydrothermal convection systems, the performance of radioactive, urban and industrial waste disposal, the study of groundwater pollution, and the understanding of natural groundwater quality patterns all require modeling tools that can consider both the transport of dissolved species as well as their interactions with solid (or other) phases in geologic media and engineered barriers. Here, a general multi-species reactive transport formulation has been developed, which is applicable to homogeneous and/or heterogeneous reactions that can proceed either subject to local equilibrium conditions or kinetic rates under non-isothermal multiphase flow conditions. Two numerical solution methods, the direct substitution approach (DSA) and sequential iteration approach (SIA) for solving the coupled complex subsurface thermo-physical-chemical processes, are described. An efficient sequential iteration approach, which solves transport of solutes and chemical reactions sequentially and iteratively, is proposed for the current reactive chemical transport computer code development. The coupled flow (water, vapor, air and heat) and solute transport equations are also solved sequentially. The existing multiphase flow code TOUGH2 and geochemical code EQ3/6 are used to implement this SIA. The flow chart of the coupled code TOUGH2-EQ3/6, required modifications of the existing codes and additional subroutines needed are presented.

  2. TOURGHREACT: A Simulation Program for Non-isothermal MultiphaseReactive Geochemical Transport in Variably Saturated GeologicMedia

    SciTech Connect (OSTI)

    Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

    2004-12-07T23:59:59.000Z

    TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media. The program was written in Fortran 77 and developed by introducing reactive geochemistry into the multiphase fluid and heat flow simulator TOUGH2. A variety of subsurface thermo-physical-chemical processes are considered under a wide range of conditions of pressure, temperature, water saturation, ionic strength, and pH and Eh. Interactions between mineral assemblages and fluids can occur under local equilibrium or kinetic rates. The gas phase can be chemically active. Precipitation and dissolution reactions can change formation porosity and permeability. The program can be applied to many geologic systems and environmental problems, including geothermal systems, diagenetic and weathering processes, subsurface waste disposal, acid mine drainage remediation, contaminant transport, and groundwater quality. Here we present two examples to illustrate applicability of the program: (1) injectivity effects of mineral scaling in a fractured geothermal reservoir and (2) CO2 disposal in a deep saline aquifer.

  3. TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions

    SciTech Connect (OSTI)

    Xu, T.; Spycher, N.; Sonnenthal, E.; Zhang, G.; Zheng, L.; Pruess, K.

    2010-08-01T23:59:59.000Z

    TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media, and was developed by introducing reactive chemistry into the multiphase fluid and heat flow simulator TOUGH2 V2. The first version of TOUGHREACT was released to the public through the U.S. Department of Energy's Energy Science and Technology Software Center (ESTSC) in August 2004. It is among the most frequently requested of ESTSC's codes. The code has been widely used for studies in CO{sub 2} geological sequestration, nuclear waste isolation, geothermal energy development, environmental remediation, and increasingly for petroleum applications. Over the past several years, many new capabilities have been developed, which were incorporated into Version 2 of TOUGHREACT. Major additions and improvements in Version 2 are discussed here, and two application examples are presented: (1) long-term fate of injected CO{sub 2} in a storage reservoir and (2) biogeochemical cycling of metals in mining-impacted lake sediments.

  4. TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive geochemical Transport in Variable Saturated Geologic Media

    SciTech Connect (OSTI)

    Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

    2004-05-24T23:59:59.000Z

    Coupled modeling of subsurface multiphase fluid and heat flow, solute transport and chemical reactions can be used for the assessment of mineral alteration in hydrothermal systems, waste disposal sites, acid mine drainage remediation, contaminant transport, and groundwater quality. A comprehensive non-isothermal multi-component reactive fluid flow and geochemical transport simulator, TOUGHREACT, has been developed. A wide range of subsurface thermo-physical-chemical processes is considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. The program can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The model can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions are considered, such as aqueous complexation, gas dissolution/exsolution, and cation exchange. Mineral dissolution/precipitation can proceed either subject to local equilibrium or kinetic conditions. Changes in porosity and permeability due to mineral dissolution and precipitation can be considered. Linear adsorption and decay can be included. For the purpose of future extensions, surface complexation by double layer model is coded in the program. Xu and Pruess (1998) developed a first version of a non-isothermal reactive geochemical transport model, TOUGHREACT, by introducing reactive geochemistry into the framework of the existing multi-phase fluid and heat flow code TOUGH2 (Pruess, 1991). Xu, Pruess, and their colleagues have applied the program to a variety of problems such as: (1) supergene copper enrichment (Xu et al, 2001), (2) caprock mineral alteration in a hydrothermal system (Xu and Pruess, 2001a), and (3) mineral trapping for CO{sub 2} disposal in deep saline aquifers (Xu et al, 2003b and 2004a). For modeling the coupled thermal, hydrological, and chemical processes during heater tests at proposed nuclear waste disposal site at Yucca Mountain (Nevada), Sonnenthal and Spycher (2000) and Spycher et al. (2003) enhanced TOUGHREACT on (1) high temperature geochemistry, (2) mineral reactive surface area calculations, and (3) porosity and permeability changes due to mineral alteration. On the other hand, Pruess et al. (1999) updated the TOUGH2 simulator to TOUGH2 V2. The present version of TOUGHREACT was developed by introducing the work of Sonnenthal and Spycher (2000) to the original work of Xu and Pruess (1998), and by replacing TOUGH2 (Pruess, 1991) by TOUGH2 V2 (Pruess et al, 1999). The TOUGHREACT program makes use of ''self-documenting'' features. It is distributed with a number of input data files for sample problems. Besides providing benchmarks for proper code installation, these can serve as self-teaching tutorial in the use of TOUGHREACT, and they provide templates to help jump-start new applications. The fluid and heat flow part of TOUGHREACT is derived from TOUGH2 V2, so in addition to the current manual, users must have manual of the TOUGH2 V2 (Pruess et al., 1999). The present version of TOUGHREACT provides the following different TOUGH2 fluid property or ''EOS'' (equation-of-state) modules: (1) EOS1 for water, or two waters with typical applications to hydrothermal problems, (2) EOS2 for multiphase mixtures of water and CO{sub 2} also with typical applications to hydrothermal problems, (3) EOS3 for multiphase mixtures of water and air with typical applications to vadose zone and nuclear waste disposal problems, (4) EOS4 that has the same capabilities as EOS3 but with vapor pressure lowering effects due to capillary pressure, (5) EOS9 for single phase water (Richards. equation) with typical applications to ambient reactive geochemical transport problems, (6) ECO2 for multiphase mixtures of water, CO{sub 2} and NaCl with typical applications to CO{sub 2} disposal in deep brine aquifers.

  5. Coupled modeling of non-isothermal multiphase flow, solutetransport and reactive chemistry in porous and fractured media: 1. ModelDevelopment and Validation

    SciTech Connect (OSTI)

    Xu, Tianfu; Pruess, Karsten

    1998-09-01T23:59:59.000Z

    Coupled modeling of subsurface multiphase fluid and heat flow, solute transport and chemical reactions can be used for the assessment of acid mine drainage remediation, mineral deposition, waste disposal sites, hydrothermal convection, contaminant transport, and groundwater quality. Here they present a numerical simulation model, TOUGHREACT, which considers non-isothermal multi-component chemical transport in both liquid and gas phases. A wide range of subsurface thermo-physical-chemical processes is considered. The model can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The model can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions is considered, such as aqueous complexation, gas dissolution/exsolution, cation exchange, and surface complexation. Mineral dissolution/precipitation can proceed either subject to local equilibrium or kinetic conditions. The coupled model employs a sequential iteration approach with reasonable computing efficiency. The development of the governing equations and numerical approach is presented along with the discussion of the model implementation and capabilities. The model is verified for a wide range of subsurface physical and chemical processes. The model is well suited for flow and reactive transport in variably saturated porous and fractured media. In the second of this two-part paper, three applications covering a variety of problems are presented to illustrate the capabilities of the model.

  6. TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media, V1.2.1

    SciTech Connect (OSTI)

    Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

    2008-09-29T23:59:59.000Z

    Coupled modeling of subsurface multiphase fluid and heat flow, solute transport, and chemical reactions can be applied to many geologic systems and environmental problems, including geothermal systems, diagenetic and weathering processes, subsurface waste disposal, acid mine drainage remediation, contaminant transport, and groundwater quality. TOUGHREACT has been developed as a comprehensive non-isothermal multi-component reactive fluid flow and geochemical transport simulator to investigate these and other problems. A number of subsurface thermo-physical-chemical processes are considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. TOUGHREACT can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The code can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions are considered, such as aqueous complexation, gas dissolution/exsolution, and cation exchange. Mineral dissolution/precipitation can take place subject to either local equilibrium or kinetic controls, with coupling to changes in porosity and permeability and capillary pressure in unsaturated systems. Chemical components can also be treated by linear adsorption and radioactive decay. The first version of the non-isothermal reactive geochemical transport code TOUGHREACT was developed (Xu and Pruess, 1998) by introducing reactive geochemistry into the framework of the existing multi-phase fluid and heat flow code TOUGH2 (Pruess, 1991). TOUGHREACT was further enhanced with the addition of (1) treatment of mineral-water-gas reactive-transport under boiling conditions, (2) an improved HKF activity model for aqueous species, (3) gas species diffusion coefficients calculated as a function of pressure, temperature, and molecular properties, (4) mineral reactive surface area formulations for fractured and porous media, and (5) porosity, permeability, and capillary pressure changes owing to mineral precipitation/dissolution (Sonnenthal et al., 1998, 2000, 2001; Spycher et al., 2003a). Subsequently, TOUGH2 V2 was released with additional EOS modules and features (Pruess et al., 1999). The present version of TOUGHREACT includes all of the previous extensions to the original version, along with the replacement of the original TOUGH2 (Pruess, 1991) by TOUGH2 V2 (Pruess et al., 1999). TOUGHREACT has been applied to a wide variety of problems, some of which are included as examples, such as: (1) Supergene copper enrichment (Xu et al., 2001); (2) Mineral alteration in hydrothermal systems (Xu and Pruess, 2001a; Xu et al., 2004b; Dobson et al., 2004); (3) Mineral trapping for CO{sub 2} disposal in deep saline aquifers (Xu et al., 2003b and 2004a); (4) Coupled thermal, hydrological, and chemical processes in boiling unsaturated tuff for the proposed nuclear waste emplacement site at Yucca Mountain, Nevada (Sonnenthal et al., 1998, 2001; Sonnenthal and Spycher, 2000; Spycher et al., 2003a, b; Xu et al., 2001); (5) Modeling of mineral precipitation/dissolution in plug-flow and fracture-flow experiments under boiling conditions (Dobson et al., 2003); (6) Calcite precipitation in the vadose zone as a function of net infiltration (Xu et al., 2003); and (7) Stable isotope fractionation in unsaturated zone pore water and vapor (Singleton et al., 2004). The TOUGHREACT program makes use of 'self-documenting' features. It is distributed with a number of input data files for sample problems. Besides providing benchmarks for proper code installation, these can serve as a self-teaching tutorial in the use of TOUGHREACT, and they provide templates to help jump-start new applications. The fluid and heat flow part of TOUGHREACT is derived from TOUGH2 V2, so in addition to the current manual, users must have the manual of the TOUGH2 V2 (Pruess et al., 1999). The present version of TOUGHREACT provides the following TOUGH2 fluid property or 'EOS' (equation-of-state) modules: (1) EOS1 for

  7. TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions

    E-Print Network [OSTI]

    Xu, T.

    2010-01-01T23:59:59.000Z

    here. 2.3. Kinetic Rate Expressions A multiple mechanismA general rate expression for intra-aqueous kinetic reactionA general rate expression for intra-aqueous kinetic reaction

  8. TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions

    E-Print Network [OSTI]

    Xu, T.

    2010-01-01T23:59:59.000Z

    S. , 2006. Metal(loid) diagenesis in mine-impacted sedimentssites, sedimentary diagenesis and CO 2 sequestration in deep

  9. TOUGHREACT: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic M

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem Not FoundInformation DOEInformation Summary Big* - 'TOUGHREACT: A Simulation

  10. T2Well/ECO2N Version 1.0: Multiphase and Non-Isothermal Model for Coupled Wellbore-Reservoir Flow of Carbon Dioxide and Variable Salinity Water

    SciTech Connect (OSTI)

    Pan, L.; Oldenburg, C.M.; Wu, Y.-S.; Pruess, K.

    2011-02-14T23:59:59.000Z

    At its most basic level, the injection of CO{sub 2} into geologic CO{sub 2} storage sites involves a system comprising the wellbore and the target reservoir. The wellbore is the only conduit available to emplace CO{sub 2} into reservoirs for long-term storage. At the same time, wellbores in general have been identified as the most likely conduit for CO{sub 2} and brine leakage from geologic carbon sequestration (GCS) sites, especially those in sedimentary basins with historical hydrocarbon production. We have developed a coupled wellbore and reservoir model for simulating the dynamics of CO{sub 2} injection and leakage through wellbores. The model describes the following processes: (1) upward or downward wellbore flow of CO{sub 2} and variable salinity water with transition from supercritical to gaseous CO{sub 2} including Joule-Thomson cooling, (2) exsolution of CO{sub 2} from the aqueous phase as pressure drops, and (3) cross flow into or interaction with layers of surrounding rock (reservoirs). We use the Drift-Flux Model and related conservation equations for describing transient two-phase non-isothermal wellbore flow of CO{sub 2}-water mixtures under different flow regimes and interacting with surrounding rock. The mass and thermal energy balance equations are solved numerically by a finite difference scheme with wellbore heat transmission to the surrounding rock handled either semi-analytically or numerically. The momentum balance equation for the flow in the wellbore is solved numerically with a semi-explicit scheme. This manual provides instructions for compilation and use of the new model, and presents some example problems to demonstrate its use.

  11. TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media, V1.2.1

    E-Print Network [OSTI]

    Xu, Tianfu

    2008-01-01T23:59:59.000Z

    using the same kinetic expression as that for dissolution.directly from kinetic expressions. For equilibrium, thesechemical system. The kinetic rate expressions for mineral

  12. Multiphase flow and multicomponent reactive transport model of the ventilation experiment in Opalinus clay

    SciTech Connect (OSTI)

    Zheng, L.; Samper, J.; Montenegro, L.; Major, J.C.

    2008-10-15T23:59:59.000Z

    During the construction and operational phases of a high-level radioactive waste (HLW) repository constructed in a clay formation, ventilation of underground drifts will cause desaturation and oxidation of the rock. The Ventilation Experiment (VE) was performed in a 1.3 m diameter unlined horizontal microtunnel on Opalinus clay at Mont Terri underground research laboratory in Switzerland to evaluate the impact of desaturation on rock properties. A multiphase flow and reactive transport model of VE is presented here. The model accounts for liquid, vapor and air flow, evaporation/condensation and multicomponent reactive solute transport with kinetic dissolution of pyrite and siderite and local-equilibrium dissolution/precipitation of calcite, ferrihydrite, dolomite, gypsum and quartz. Model results reproduce measured vapor flow, liquid pressure and hydrochemical data and capture the trends of measured relative humidities, although such data are slightly overestimated near the rock interface due to uncertainties in the turbulence factor. Rock desaturation allows oxygen to diffuse into the rock and triggers pyrite oxidation, dissolution of calcite and siderite, precipitation of ferrihydrite, dolomite and gypsum and cation exchange. pH in the unsaturated rock varies from 7.8 to 8 and is buffered by calcite. Computed changes in the porosity and the permeability of Opalinus clay in the unsaturated zone caused by oxidation and mineral dissolution/precipitation are smaller than 5%. Therefore, rock properties are not expected to be affected significantly by ventilation of underground drifts during construction and operational phases of a HLW repository in clay.

  13. Electrochimica Acta 53 (2007) 610621 Non-isothermal cold start of polymer electrolyte fuel cells

    E-Print Network [OSTI]

    2007-01-01T23:59:59.000Z

    by comparing a non-isothermal cold start with an isothermal one. It is found that more water is transported of water transport with heat transport and hence the rising cell temperature effect in non-isothermal coldElectrochimica Acta 53 (2007) 610­621 Non-isothermal cold start of polymer electrolyte fuel cells

  14. Corrosion-induced gas generation in a nuclear waste repository: Reactive geochemistry and multiphase flow effect

    E-Print Network [OSTI]

    Xu, T.

    2009-01-01T23:59:59.000Z

    Lying Repositories for Nuclear Waste, NAGRA Technical Reporthost rock formation for nuclear waste storage. EngineeringGas Generation in a Nuclear Waste Repository: Reactive

  15. Microstructure and strength modelling of AlCuMg alloys during non-isothermal

    E-Print Network [OSTI]

    -clusters Introduction Non-isothermal processes may involve very rapid temperature changes, such as in welding to test/verify the model predictions in situ and in a companion paper the model is applied to welding

  16. Corrosion-induced gas generation in a nuclear waste repository: Reactive geochemistry and multiphase flow effect

    SciTech Connect (OSTI)

    Xu, T.; Senger, R.; Finsterle, S.

    2008-10-15T23:59:59.000Z

    Corrosion of steel canisters, stored in a repository for spent fuel and high-level nuclear wastes, leads to the generation and accumulation of hydrogen gas in the backfilled emplacement tunnels, which may significantly affect long-term repository safety. Previous studies used H{sub 2} generation rates based on the volume of the waste or canister material and the stoichiometry of the corrosion reaction. However, iron corrosion and H{sub 2} generation rates vary with time, depending on factors such as amount of iron, water availability, water contact area, and aqueous and solid chemistry. To account for these factors and feedback mechanisms, we developed a chemistry model related to iron corrosion, coupled with two-phase (liquid and gas) flow phenomena that are driven by gas-pressure buildup associated with H{sub 2} generation and water consumption. Results indicate that by dynamically calculating H{sub 2} generation rates based on a simple model of corrosion chemistry, and by coupling this corrosion reaction with two-phase flow processes, the degree and extent of gas pressure buildup could be much smaller compared to a model that neglects the coupling between flow and reactive transport mechanisms. By considering the feedback of corrosion chemistry, the gas pressure increases initially at the canister, but later decreases and eventually returns to a stabilized pressure that is slightly higher than the background pressure. The current study focuses on corrosion under anaerobic conditions for which the coupled hydrogeochemical model was used to examine the role of selected physical parameters on the H{sub 2} gas generation and corresponding pressure buildup in a nuclear waste repository. The developed model can be applied to evaluate the effect of water and mineral chemistry of the buffer and host rock on the corrosion reaction for future site-specific studies.

  17. Dispersed Phase of Non-Isothermal Particles in Rotating Turbulent Flows

    E-Print Network [OSTI]

    Pandya, R V R

    2015-01-01T23:59:59.000Z

    We suggest certain effects, caused by interaction between rotation and gravitation with turbulence structure, for the cooling/heating of dispersed phase of non-isothermal particles in rotating turbulent fluid flows. These effects are obtained through the derivation of kinetic or probability density function based macroscopic equations for the particles. In doing so, for one-way temperature coupling, we also show that homogeneous, isotropic non-isothermal fluid turbulence does not influence the mean temperature (though it influences mean velocity) of the dispersed phase of particles settling due to gravitational force in the isotropic turbulence.

  18. A non-isothermal PEM fuel cell model including two water transport mechanisms in the

    E-Print Network [OSTI]

    Münster, Westfälische Wilhelms-Universität

    A non-isothermal PEM fuel cell model including two water transport mechanisms in the membrane K Freiburg Germany A dynamic two-phase flow model for proton exchange mem- brane (PEM) fuel cells and the species concentrations. In order to describe the charge transport in the fuel cell the Poisson equations

  19. A NON-ISOTHERMAL FATIGUE CRACK GROWTH LAW FOR THE A356-T7 ALUMINUM ALLOY

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 A NON-ISOTHERMAL FATIGUE CRACK GROWTH LAW FOR THE A356-T7 ALUMINUM ALLOY E. Merhy 1,2,3* , L rate, Damage tolerant design, Life time prediction, A356 cast alloy ABSTRACT Fatigue crack growth period in cylinder heads of A356-T7 casting alloy has been found to constitute an important part

  20. Lyapunov-based control of non isothermal continuous stirred tank reactors using

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Lyapunov-based control of non isothermal continuous stirred tank reactors using irreversible availability function is used as a Lyapunov function for the practical derivation of non linear control laws of the outlet flow of the CSTR. Several control laws are then derived which insure global asymptotic stability

  1. Non-isothermal preform infiltration during the vacuum-assisted resin transfer molding (VARTM) process

    E-Print Network [OSTI]

    Grujicic, Mica

    the infiltration of a rectangular carbon fiber based preform with the NBV-800 epoxy resin and to optimize the VARTMNon-isothermal preform infiltration during the vacuum-assisted resin transfer molding (VARTM-element model is developed to analyze the infiltration of a fiber preform with resin under non- isothermal

  2. Heat and mass transport in non-isothermal partially saturated oil-wax Antonio Fasano1

    E-Print Network [OSTI]

    Primicerio, Mario

    Heat and mass transport in non-isothermal partially saturated oil-wax solutions Antonio Fasano1 of deposition on a cold wall. Here we want to investigate the specific problem of diffusion-driven migration of desaturation. Our approach will be mainly focussed on the mass transport process, in the sense that the (rather

  3. Modeling for non isothermal cavitation using four-equation Eric Goncalv`es

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Modeling for non isothermal cavitation using four-equation models Eric Goncalv`es LEGI-fluid solver has been developed to investigate the behaviour of cavitation models including thermodynamic between phases are studied. Numerical simulations are firstly performed on rarefaction cavitating problems

  4. Rarefied gas flow in a rectangular enclosure induced by non-isothermal walls

    SciTech Connect (OSTI)

    Vargas, Manuel; Tatsios, Giorgos; Valougeorgis, Dimitris, E-mail: diva@mie.uth.gr [Department of Mechanical Engineering, University of Thessaly, 38334 Volos (Greece)] [Department of Mechanical Engineering, University of Thessaly, 38334 Volos (Greece); Stefanov, Stefan [Institute of Mechanics, Bulgarian Academy of Sciences, Sofia (Bulgaria)] [Institute of Mechanics, Bulgarian Academy of Sciences, Sofia (Bulgaria)

    2014-05-15T23:59:59.000Z

    The flow of a rarefied gas in a rectangular enclosure due to the non-isothermal walls with no synergetic contributions from external force fields is investigated. The top and bottom walls are maintained at constant but different temperatures and along the lateral walls a linear temperature profile is assumed. Modeling is based on the direct numerical solution of the Shakhov kinetic equation and the Direct Simulation Monte Carlo (DSMC) method. Solving the problem both deterministically and stochastically allows a systematic comparison and verification of the results as well as the exploitation of the numerical advantages of each approach in the investigation of the involved flow and heat transfer phenomena. The thermally induced flow is simulated in terms of three dimensionless parameters characterizing the problem, namely, the reference Knudsen number, the temperature ratio of the bottom over the top plates, and the enclosure aspect ratio. Their effect on the flow configuration and bulk quantities is thoroughly examined. Along the side walls, the gas flows at small Knudsen numbers from cold-to-hot, while as the Knudsen number is increased the gas flows from hot-to-cold and the thermally induced flow configuration becomes more complex. These flow patterns with the hot-to-cold flow to be extended to the whole length of the non-isothermal side walls may exist even at small temperature differences and then, they are enhanced as the temperature difference between the top and bottom plates is increased. The cavity aspect ratio also influences this flow configuration and the hot-to-cold flow is becoming more dominant as the depth compared to the width of the cavity is increased. To further analyze the flow patterns a novel solution decomposition into ballistic and collision parts is introduced. This is achieved by accordingly modifying the indexing process of the typical DSMC algorithm. The contribution of each part of the solution is separately examined and a physical interpretation of the flow configuration, including the hot-to-cold flow close to the side walls, in the whole range of the Knudsen number is provided.

  5. Glass transition and crystallization kinetics of a barium borosilicate glass by a non-isothermal method

    SciTech Connect (OSTI)

    Lopes, Andreia A. S.; Soares, Roque S.; Lima, Maria M. A.; Monteiro, Regina C. C., E-mail: rcm@fct.unl.pt [Department of Materials Science, CENIMAT/I3N, Faculty of Sciences and Technology, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2014-01-28T23:59:59.000Z

    The glass transition and crystallization kinetics of a glass with a molar composition 60BaO-30B{sub 2}O{sub 3}-10SiO{sub 2} were investigated by differential scanning calorimetry (DSC) under non-isothermal conditions. DSC curves exhibited an endothermic peak associated with the glass transition and two partially overlapped exothermic peaks associated with the crystallization of the glass. The dependence of the glass transition temperature (T{sub g}) and of the maximum crystallization temperature (T{sub p}) on the heating rate was used to determine the activation energy associated with the glass transition (E{sub g}), the activation energy for crystallization (E{sub c}), and the Avrami exponent (n). X-ray diffraction (XRD) revealed that barium borate (?-BaB{sub 2}O{sub 4}) was the first crystalline phase to be formed followed by the formation of barium silicate (Ba{sub 5}Si{sub 8}O{sub 21}). The variations of activation energy for crystallization and of Avrami exponent with the fraction of crystallization (?) were also examined. When the crystallization fraction (?) increased from 0.1 to 0.9, the value of local activation energy (E{sub c}(?)) decreased from 554 to 458?kJ/mol for the first exothermic peak and from 1104 to 831?kJ/mol for the second exothermic peak. The value determined for the Avrami exponent was near 2 indicating a similar one-dimensional crystallization mechanism for both crystalline phases. This was confirmed by the morphological studies performed by scanning electron microscopy (SEM) on glass samples heat-treated at the first and at the second crystallization temperatures.

  6. Fourier Law and Non-Isothermal Boundary in the Boltzmann Theory

    E-Print Network [OSTI]

    Raffaele Esposito; Yan Guo; Chanwoo Kim; Rossana Marra

    2012-02-13T23:59:59.000Z

    In the study of the heat transfer in the Boltzmann theory, the basic problem is to construct solutions to the steady problem for the Boltzmann equation in a general bounded domain with diffuse reflection boundary conditions corresponding to a non isothermal temperature of the wall. Denoted by \\delta the size of the temperature oscillations on the boundary, we develop a theory to characterize such a solution mathematically. We construct a unique solution F_s to the Boltzmann equation, which is dynamically asymptotically stable with exponential decay rate. Moreover, if the domain is convex and the temperature of the wall is continuous we show that F_s is continuous away from the grazing set. If the domain is non-convex, discontinuities can form and then propagate along the forward characteristics. We show that they actually form for a suitable smooth temperature profile. We remark that this solution differs from a local equilibrium Maxwellian, hence it is a genuine non equilibrium stationary solution. Our analysis is based on recent studies of the boundary value problems for the Boltzmann equation but with new constructive coercivity estimates for both steady and dynamic cases. A natural question in this setup is to determine if the general Fourier law, stating that the heat conduction vector q is proportional to the temperature gradient, is valid. As an application of our result we establish an expansion in \\delta for F_s whose first order term F_1 satisfies a linear, parameter free equation. Consequently, we discover that if the Fourier law were valid for F_s, then the temperature of F_1 must be linear in a slab. Such a necessary condition contradicts available numerical simulations, leading to the prediction of break-down of the Fourier law in the kinetic regime.

  7. The effect of non-isothermality on the gravitational collapse of spherical clouds and the evolution of protostellar accretion

    E-Print Network [OSTI]

    E. I. Vorobyov; Shantanu Basu

    2005-08-19T23:59:59.000Z

    We investigate the role of non-isothermality in gravitational collapse and protostellar accretion by explicitly including the effects of molecular radiative cooling, gas-dust energy transfer, and cosmic ray heating in models of spherical hydrodynamic collapse. Isothermal models have previously shown an initial decline in the mass accretion rate \\dot{M}, due to a gradient of infall speed that develops in the prestellar phase. Our results show that: (1) in the idealized limit of optically thin cooling, a positive temperature gradient is present in the prestellar phase which effectively cancels out the effect of the velocity gradient, producing a near constant \\dot{M} in the early accretion phase; (2) in the more realistic case including cooling saturation at higher densities, \\dot{M} may initially be either weakly increasing or weakly decreasing with time, for low (T_d ~ 6 K) and high dust temperature (T_d ~ 10 K) cases, respectively. Hence, our results show that the initial decline in \\dot{M} seen in isothermal models is definitely not enhanced by non-isothermal effects, and is often suppressed by them. In all our models, \\dot{M} does eventually decline rapidly due to the finite mass condition on our cores and a resulting inward propagating rarefaction wave. Thus, any explanation for a rapid decline of $\\dot{M}$ in the accretion phase likely needs to appeal to the global molecular cloud structure and possible envelope support, which results in a finite mass reservoir for cores.

  8. Multiphase flow calculation software

    DOE Patents [OSTI]

    Fincke, James R. (Idaho Falls, ID)

    2003-04-15T23:59:59.000Z

    Multiphase flow calculation software and computer-readable media carrying computer executable instructions for calculating liquid and gas phase mass flow rates of high void fraction multiphase flows. The multiphase flow calculation software employs various given, or experimentally determined, parameters in conjunction with a plurality of pressure differentials of a multiphase flow, preferably supplied by a differential pressure flowmeter or the like, to determine liquid and gas phase mass flow rates of the high void fraction multiphase flows. Embodiments of the multiphase flow calculation software are suitable for use in a variety of applications, including real-time management and control of an object system.

  9. Morphology and non-isothermal crystallization kinetics of CuInS{sub 2} nanocrystals synthesized by solvo-thermal method

    SciTech Connect (OSTI)

    Majeed Khan, M.A., E-mail: majeed_phys@yahoo.co.in [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia); Kumar, Sushil [Department of Physics, Chaudhary Devi Lal University, Sirsa 125055 (India); Alsalhi, M.S. [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia); Department of Physics and Astronomy, King Saud University, Riyadh 11451 (Saudi Arabia); Ahamed, Maqusood [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia); Alhoshan, Mansour [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia); Chemical Engineering Department, King Saud University, Riyadh 11451 (Saudi Arabia); Alrokayan, Salman A. [King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451 (Saudi Arabia); Ahamad, Tansir [Department of Chemistry, King Saud University, Riyadh 11451 (Saudi Arabia)

    2012-03-15T23:59:59.000Z

    Nanocrystals of copper indium disulphide (CuInS{sub 2}) were synthesized by a solvo-thermal method. The structure, morphology and non-isothermal crystallization kinetic behavior of samples were investigated using X-ray diffraction, field emission scanning electron microscopy, field emission transmission electron microscopy, thermogravimetric analysis and differential thermal analysis techniques. Non-isothermal measurements at different heating rates were carried out and the crystallization kinetics of samples were analyzed using the most reliable non-isothermal kinetic methods. The kinetic parameters such as glass transition temperature, thermal stability, activation energy, Avrami exponent etc. were evaluated. - Highlights: Black-Right-Pointing-Pointer CuInS{sub 2} nanocrystals have scientific and technological importance. Black-Right-Pointing-Pointer Samples have been prepared by solvo-thermal method. Black-Right-Pointing-Pointer Synthesized samples exhibit excellent morphology and thermal properties. Black-Right-Pointing-Pointer Investigated properties may be utilized in design and fabrication of solar cell devices.

  10. An inventory of Lattice Boltzmann models of multiphase flows

    E-Print Network [OSTI]

    Erik Aurell; Minh Do-Quang

    2001-05-18T23:59:59.000Z

    This document reports investigations of models of multiphase flows using Lattice Boltzmann methods. The emphasis is on deriving by Chapman-Enskog techniques the corresponding macroscopic equations. The singular interface (Young-Laplace-Gauss) model is described briefly, with a discussion of its limitations. The diffuse interface theory is discussed in more detail, and shown to lead to the singular interface model in the proper asymptotic limit. The Lattice Boltzmann method is presented in its simplest form appropriate for an ideal gas. Four different Lattice Boltzmann models for non-ideal (multi-phase) isothermal flows are then presented in detail, and the resulting macroscopic equations derived. Partly in contradiction with the published literature, it is found that only one of the models gives physically fully acceptable equations. The form of the equation of state for a multiphase system in the density interval above the coexistance line determines surface tension and interface thickness in the diffuse interface theory. The use of this relation for optimizing a numerical model is discussed. The extension of Lattice Boltzmann methods to the non-isothermal situation is discussed summarily.

  11. Multi-phasing CFD

    SciTech Connect (OSTI)

    Stosic, Zoran V. [Framatome ANP GmbH, P.O. Box 3220, 91050 Erlangen (Germany); Stevanovic, Vladimir D. [University of Belgrade, Kraljice Marije 16, 11000 Belgrade, Serbia and Montenegro (Yugoslavia)

    2002-07-01T23:59:59.000Z

    Computational fluid dynamics for multiphase flows is an emerging field. Due to the complexity and divergence of multiphase thermal and hydraulic problems, further development of multiphase flow modelling, closure laws and numerical methods is needed in order to achieve the general purpose and optimised CFD (Computational Fluid Dynamics) methods, which will be applicable to the wide variety of multiphase flow problems. In the paper, an original approach to the various aspects of multiphase CFD modelling is presented. It is based on the multi-fluid modelling approach, development of necessary closure laws and derivation of appropriate numerical methods for efficient governing equations solution. Velocity and pressure fields are solved with the SIMPLE (Semi-Implicit Method for Pressure-Linked Equations) type pressure-corrector method developed for the multiphase flow conditions. For the solution of scalar parameters transport equations both implicit and explicit methods are presented. The implicit method is suitable for steady state, slow transients and problems without the sharp fronts propagation. Explicit method is developed in order to predict scalar parameters fronts propagation, as well as phase interface tracking problems. The challenge towards the multiphase flow solution on both the macro and micro level is presented in order to perform multiphase CFD simulations and analyses of multiphase flows in complex geometry of nuclear power plant components, such as nuclear fuel rod bundles thermal-hydraulics. Presented methodology and obtained CFD results comprise micro-scale phenomena of phases' separation, interface tracking, heated surfaces dry-out and critical heat flux occurrence, as well as macro-scale transport and distributions of phase volumes. (authors)

  12. Multiphase Sequestration Geochemistry: Model for Mineral Carbonation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Multiphase Sequestration Geochemistry: Model for Mineral Carbonation. Multiphase Sequestration Geochemistry: Model for Mineral Carbonation. Abstract: Carbonation of formation...

  13. Non-isothermal kinetic studies of co-combustion and co-cracking of coal and plastic blends using thermogravimetric analysis

    SciTech Connect (OSTI)

    Nabeel, A.; Khan, T.A.; Sharma, D.K. [Jamia Millia Islamia, New Delhi (India). Dept. of Chemistry

    2009-07-01T23:59:59.000Z

    The kinetics of co-combustion/co-cracking of Topa coal with polystyrene, poly(vinyl chloride), and bakelite have been studied by theromogravimetric analysis at a linear heating rate of 20C/min in a stream of air for combustion and in nitrogen for cracking with a flow rate of 20 cm{sup 3}/min up to the temperature of 900C under non-isothermal conditions. The order of reaction and overall activation energy of the reactions have been calculated. These studies may help in synergistic production of value-added organic compounds and spatiality chemicals from coal and plastics.

  14. Multiphase cooling flows

    E-Print Network [OSTI]

    Peter A. Thomas

    1996-08-20T23:59:59.000Z

    I discuss the multiphase nature of the intracluster medium whose neglect can lead to overestimates of the baryon fraction of clusters by up to a factor of two. The multiphase form of the cooling flow equations are derived and reduced to a simple form for a wide class of self-similar density distributions. It is shown that steady-state cooling flows are \\emph{not} consistent with all possible emissivity profiles which can therefore be used as a test of the theory. In combination, they provide strong constraints on the mass distribution within the cooling radius.

  15. Multiphase fluid characterization system

    DOE Patents [OSTI]

    Sinha, Dipen N.

    2014-09-02T23:59:59.000Z

    A measurement system and method for permitting multiple independent measurements of several physical parameters of multiphase fluids flowing through pipes are described. Multiple acoustic transducers are placed in acoustic communication with or attached to the outside surface of a section of existing spool (metal pipe), typically less than 3 feet in length, for noninvasive measurements. Sound speed, sound attenuation, fluid density, fluid flow, container wall resonance characteristics, and Doppler measurements for gas volume fraction may be measured simultaneously by the system. Temperature measurements are made using a temperature sensor for oil-cut correction.

  16. MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER

    E-Print Network [OSTI]

    Lahey, Richard T.

    MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER "ENGINEERING APPLICATIONS OF FRACTAL AND CHAOS THEORY" RICHARD T. LAHEY, JR. Center for Multiphase Research Rensselaer Polytechnic Institute Troy and multiphase flow & heat transfer will be stressed. This paper will begin by reviewing some important concepts

  17. Multi-criteria based design approach of multiphase permanent magnet low speed synchronous machines

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    dedicated to multiphase Permanent Magnet Synchronous Machines (PMSM) supplied by Pulse Width Modulation to use PWM VSI for supplying high power propulsion machines [1]. The induction machines and the PMSM can be easily considered in this instance since the constraint on the reactive power does not apply [2]. PMSM

  18. Flow assurance and multiphase pumping

    E-Print Network [OSTI]

    Nikhar, Hemant G.

    2009-05-15T23:59:59.000Z

    the number of deepwater developments between 1994 and 2004. Number of new deepwater fields coming up continues to increase year by year. Fig. 5: Number of Deepwater Developments 6 9 The first subsea Christmas tree was installed in 1961 and it took...??????????????????????????????????????.. 12 Subsea Process?????????????????????????????????????. 12 VASPS??????????????????????????????????????????. 13 Multiphase Pumping??????????????????????????????????? 14 Inbuilt Capability of Twin-Screw Pumps to Handle Slugs???????????????? 16...

  19. Extremal structures of multiphase heat conducting composites

    E-Print Network [OSTI]

    Cherkaev, Andrej

    Extremal structures of multiphase heat conducting composites A.V. Cherkaev \\Lambda L.V. Gibiansky y April 19, 1995 Abstract In this paper we construct microstructures of multiphase composites with un be easily gen­ eralized for the three­dimensional composites with arbitrary number of phases. 1 Introduction

  20. Multiphase Flow Analysis in Hydra-TH

    SciTech Connect (OSTI)

    Christon, Mark A. [Los Alamos National Laboratory; Bakosi, Jozsef [Los Alamos National Laboratory; Francois, Marianne M. [Los Alamos National Laboratory; Lowrie, Robert B. [Los Alamos National Laboratory; Nourgaliev, Robert [Idaho National Laboratory

    2012-06-20T23:59:59.000Z

    This talk presents an overview of the multiphase flow efforts with Hydra-TH. The presentation begins with a definition of the requirements and design principles for multiphase flow relevant to CASL-centric problems. A brief survey of existing codes and their solution algorithms is presented before turning the model formulation selected for Hydra-TH. The issues of hyperbolicity and wellposedness are outlined, and a three candidate solution algorithms are discussed. The development status of Hydra-TH for multiphase flow is then presented with a brief summary and discussion of future directions for this work.

  1. Multiphase transport model for relativistic nuclear collisions 

    E-Print Network [OSTI]

    Zhang, B.; Ko, Che Ming; Li, Ba; Lin, ZW.

    2000-01-01T23:59:59.000Z

    To study heavy ion collisions at energies available from the Relativistic Heavy Ion Collider (RHIC), we have developed a multiphase transport model that includes both initial partonic and final hadronic interactions. Specifically, the Zhang's parton...

  2. Accurate solution algorithms for incompressible multiphase flows

    SciTech Connect (OSTI)

    Rider, W.J.; Kothe, D.B.; Mosso, S.J.; Cerutti, J.H. [Los Alamos National Lab., NM (United States); Hochstein, J.I. [Memphis State Univ., TN (United States). Dept. of Mechanical Engineering

    1994-10-19T23:59:59.000Z

    A number of advances in modeling multiphase incompressible flow are described. These advances include high-order Godunov projection methods, piecewise linear interface reconstruction and tracking and the continuum surface force model. Examples are given.

  3. Multiphase transport model for relativistic nuclear collisions

    E-Print Network [OSTI]

    Zhang, B.; Ko, Che Ming; Li, Ba; Lin, ZW.

    2000-01-01T23:59:59.000Z

    To study heavy ion collisions at energies available from the Relativistic Heavy Ion Collider (RHIC), we have developed a multiphase transport model that includes both initial partonic and final hadronic interactions. Specifically, the Zhang's parton...

  4. NUMERICAL MODELING FOR MULTIPHASE INCOMPRESSIBLE FLOW WITH PHASE CHANGE

    E-Print Network [OSTI]

    Abdou, Mohamed

    NUMERICAL MODELING FOR MULTIPHASE INCOMPRESSIBLE FLOW WITH PHASE CHANGE Xiao-Yong Luo, Ming-Jiu Ni for multiphase flows. A con- tinuum surface force (CSF) tension model is used in the present cases. Phase change

  5. Implications for Eulerian-Lagrangian modeling of multiphase ...

    E-Print Network [OSTI]

    Adjoint methods are particle methods: Implications for Eulerian-Lagrangian modeling of multiphase multicomponent transport Thomas F. Russell Division of

  6. Large-eddy simulation of multiphase flows in complex combustors

    E-Print Network [OSTI]

    Mahesh, Krishnan

    Large-eddy simulation of multiphase flows in complex combustors S. V. Apte1 , K. Mahesh2 , F. Ham1 to accurately predict reacting multi-phase flows in practical combustors involving complex physical phenomena-turbine combustor geometries to evaluate the predictions made for multiphase, turbulent flow. 1 Introduction

  7. Boundary Integral Methods for Multicomponent Fluids and Multiphase Materials

    E-Print Network [OSTI]

    integral methods in two dimensions to multi-component fluid flows and multi-phase problems in materials, and more recently to multi-phase problems in materials science. By multi-fluid or multi-phase we mean systems where the constituitive properties of the fluid or material change abruptly at a dividing

  8. Boundary Integral Methods for Multicomponent Fluids and Multiphase Materials

    E-Print Network [OSTI]

    integral methods in two dimensions to multi­component fluid flows and multi­phase problems in materials, and more recently to multi­phase problems in materials science. By multi­fluid or multi­phase we mean systems where the constituitive properties of the fluid or material change abruptly at a dividing

  9. A projection approach for multiphase flows Daniel Hartmann

    E-Print Network [OSTI]

    Dabiri, John O.

    A projection approach for multiphase flows Daniel Hartmann and Tim Colonius Division of Engineering of the Rayleigh-Taylor instability are presented to validate the new method. I. Introduction Multiphase flows, for which efficient numerical methods are available. In the case of a multiphase flow, however

  10. Multiphase Turbulent Flow Ken Kiger -UMCP

    E-Print Network [OSTI]

    Gruner, Daniel S.

    emulsions Multi-phase Steam bubble in H20 Ice slurry Coal particles in air Sand particle in H20 #12://www.physics.utoronto.ca/~nonlin/turbidity/turbidity.html #12;Material processing ­ generation of particles & composite materials Energy production ­ coal

  11. Multiphase autoresonant excitations in discrete nonlinear Schrdinger systems Y. Gopher and L. Friedland

    E-Print Network [OSTI]

    Friedland, Lazar

    Multiphase autoresonant excitations in discrete nonlinear Schrödinger systems Y. Gopher and L September 2005 Large amplitude, multiphase solutions of periodic discrete nonlinear Schrödinger NLS systems of an external parameter driving frequency . Numerical examples of excitation of multiphase waves and periodic

  12. Efficiency and Leakage Analysis of a Twin-Screw Multiphase Pump 

    E-Print Network [OSTI]

    Turhan, Yusuf

    2014-04-01T23:59:59.000Z

    Multiphase twin-screw pumps have become an important alternative to produce the oil and natural gas from wells. In comparison to a conventional multiphase oil production systems, a multiphase twin screw pump provides larger boost with smaller...

  13. Error handling strategies in multiphase inverse modeling

    SciTech Connect (OSTI)

    Finsterle, S.; Zhang, Y.

    2010-12-01T23:59:59.000Z

    Parameter estimation by inverse modeling involves the repeated evaluation of a function of residuals. These residuals represent both errors in the model and errors in the data. In practical applications of inverse modeling of multiphase flow and transport, the error structure of the final residuals often significantly deviates from the statistical assumptions that underlie standard maximum likelihood estimation using the least-squares method. Large random or systematic errors are likely to lead to convergence problems, biased parameter estimates, misleading uncertainty measures, or poor predictive capabilities of the calibrated model. The multiphase inverse modeling code iTOUGH2 supports strategies that identify and mitigate the impact of systematic or non-normal error structures. We discuss these approaches and provide an overview of the error handling features implemented in iTOUGH2.

  14. automated multiphasic health: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    R., M. Eng. Massachusetts Institute of Technology 2007-01-01 10 Multiphase Stirling Engines CiteSeer Summary: Analysis, design, fabrication, and experimental assessment of a...

  15. Continuous multi-phase feeding of broiler chickens

    E-Print Network [OSTI]

    Nasril

    2005-02-17T23:59:59.000Z

    , continuous multi-phase feeding of broiler chickens using corn-soy diets does not appear to be justified by either increased performance or reduced nitrogen excretion....

  16. Proton equilibration in the chloroplast modulates multiphasic kinetics of nonphotochemical quenching

    E-Print Network [OSTI]

    Proton equilibration in the chloroplast modulates multiphasic kinetics of nonphotochemical analysis demonstrates that multiphasic quenching re- laxation mainly reflects the existence of at least two

  17. Reactive Maintenance

    Broader source: Energy.gov [DOE]

    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.

  18. Global minimizers for axisymmetric multiphase membranes

    E-Print Network [OSTI]

    Rustum Choksi; Marco Morandotti; Marco Veneroni

    2012-04-30T23:59:59.000Z

    We consider a Canham-Helfrich-type variational problem defined over closed surfaces enclosing a fixed volume and having fixed surface area. The problem models the shape of multiphase biomembranes. It consists of minimizing the sum of the Canham-Helfrich energy, in which the bending rigidities and spontaneous curvatures are now phase-dependent, and a line tension penalization for the phase interfaces. By restricting attention to axisymmetric surfaces and phase distributions, we extend our previous results for a single phase (arXiv:1202.1979) and prove existence of a global minimizer.

  19. Theory and Simulation of Multiphase Polymer Systems

    E-Print Network [OSTI]

    Friederike Schmid

    2010-01-08T23:59:59.000Z

    The theory of multiphase polymer systems has a venerable tradition. The 'classical' theory of polymer demixing, the Flory-Huggins theory, was developed already in the forties of the last century. It is still the starting point for most current approaches -- be they improved theories for polymer (im)miscibility that take into account the microscopic structure of blends more accurately, or sophisticated field theories that allow to study inhomogeneous multicomponent systems of polymers with arbitrary architectures in arbitrary geometries. In contrast, simulations of multiphase polymer systems are relatively young. They are still limited by the fact that one must simulate a large number of large molecules in order to obtain meaningful results. Both powerful computers and smart modeling and simulation approaches are necessary to overcome this problem. This article gives an overview over the state-of-the art in both areas, theory and simulation. While the theory has reached a fairly mature stage by now, and many aspects of it are covered in textbooks on polymer physics, the information on simulations is much more scattered. This is why some effort has been invested into putting together a representative list of references in this area (up to the year of 2008) -- which is of course still far from complete.

  20. Reactive Gliosis Reactive Oxygen Species: Superoxide

    E-Print Network [OSTI]

    . By sensing the electric signals generated by other 3368 Reactive Gliosis #12;individuals, mormyrids are alsoReactive Gliosis Glial Scar Reactive Oxygen Species: Superoxide Anions Neuroinflammation motor output. Reafferent Control in Electric Communication Reafferent Control in Electric Communication

  1. Plasmas in Multiphase Media: Bubble Enhanced Discharges in Liquids and Plasma/Liquid Phase Boundaries

    SciTech Connect (OSTI)

    Kushner, Mark Jay [University of Michigan] [University of Michigan

    2014-07-10T23:59:59.000Z

    In this research project, the interaction of atmospheric pressure plasmas with multi-phase media was computationally investigated. Multi-phase media includes liquids, particles, complex materials and porous surfaces. Although this investigation addressed fundamental plasma transport and chemical processes, the outcomes directly and beneficially affected applications including biotechnology, medicine and environmental remediation (e.g., water purification). During this project, we made advances in our understanding of the interaction of atmospheric pressure plasmas in the form of dielectric barrier discharges and plasma jets with organic materials and liquids. We also made advances in our ability to use computer modeling to represent these complex processes. We determined the method that atmospheric pressure plasmas flow along solid and liquid surfaces, and through endoscopic like tubes, deliver optical and high energy ion activation energy to organic and liquid surfaces, and produce reactivity in thin liquid layers, as might cover a wound. We determined the mechanisms whereby plasmas can deliver activation energy to the inside of liquids by sustaining plasmas in bubbles. These findings are important to the advancement of new technology areas such as plasma medicine

  2. Gasificaton Transport: A Multiphase CFD Approach & Measurements

    SciTech Connect (OSTI)

    Dimitri Gidaspow; Veeraya Jiradilok; Mayank Kashyap; Benjapon Chalermsinsuwan

    2009-02-14T23:59:59.000Z

    The objective of this project was to develop predictive theories for the dispersion and mass transfer coefficients and to measure them in the turbulent fluidization regime, using existing facilities. A second objective was to use our multiphase CFD tools to suggest optimized gasifier designs consistent with aims of Future Gen. We have shown that the kinetic theory based CFD codes correctly compute: (1) Dispersion coefficients; and (2) Mass transfer coefficients. Hence, the kinetic theory based CFD codes can be used for fluidized bed reactor design without any such inputs. We have also suggested a new energy efficient method of gasifying coal and producing electricity using a molten carbonate fuel cell. The principal product of this new scheme is carbon dioxide which can be converted into useful products such as marble, as is done very slowly in nature. We believe this scheme is a lot better than the canceled FutureGen, since the carbon dioxide is safely sequestered.

  3. alliage polycristallin multiphase: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 21 Multiphase Stirling Engines CiteSeer Summary: Analysis, design, fabrication, and experimental assessment of a...

  4. Deuteron-nucleus collisions in a multiphase transport model 

    E-Print Network [OSTI]

    Lin, ZW; Ko, Che Ming.

    2003-01-01T23:59:59.000Z

    Using a multiphase transport model, we study pseudorapidity distributions and transverse momentum spectra in deuteron-gold collisions at RHIC. We find that final-state partonic and hadronic interactions affect the transverse momentum spectrum...

  5. Integral Model of a Multiphase Plume in Quiescent Stratification

    E-Print Network [OSTI]

    Crounse, B. C.

    The writers present a one-dimensional integral model to describe multiphase plumes discharged to quiescent stratified receiving waters. The model includes an empirical submodel for detrainment, and the capability to include ...

  6. Continuous multi-phase feeding of broiler chickens 

    E-Print Network [OSTI]

    Nasril

    2005-02-17T23:59:59.000Z

    Continuous multi-phase feeding of broiler chickens was evaluated to optimize broiler nutrition and minimize environmental impact related to excess nitrogen in poultry manure. Four experiments were conducted. Experiments 1 and 2 studied effects...

  7. Post-Project Performance Assessment of a Multi-Phase Urban Stream Restoration Project on Lower Codornices Creek

    E-Print Network [OSTI]

    Docto, Mia; Hoffman, Johanna; Walls, Scott

    2011-01-01T23:59:59.000Z

    of a Multi-Phase Urban Stream Restoration Project on Lowerof a Multi-Phase Urban Stream Restoration Project on Lowerof a Multi-Phase Urban Stream Restoration Project on Lower

  8. Technical Report on NETL's Non Newtonian Multiphase Slurry Workshop: A path forward to understanding non-Newtonian multiphase slurry flows

    SciTech Connect (OSTI)

    Edited by Guenther, Chris; Garg, Rahul

    2013-08-19T23:59:59.000Z

    The Department of Energy’s (DOE) National Energy Technology Laboratory (NETL) sponsored a workshop on non-Newtonian multiphase slurry at NETL’s Morgantown campus August 19 and 20, 2013. The objective of this special two-day meeting of 20-30 invited experts from industry, National Labs and academia was to identify and address technical issues associated with handling non-Newtonian multiphase slurries across various facilities managed by DOE. Particular emphasis during this workshop was placed on applications managed by the Office of Environmental Management (EM). The workshop was preceded by two webinars wherein personnel from ORP and NETL provided background information on the Hanford WTP project and discussed the critical design challenges facing this project. In non-Newtonian fluids, viscosity is not constant and exhibits a complex dependence on applied shear stress or deformation. Many applications under EM’s tank farm mission involve non-Newtonian slurries that are multiphase in nature; tank farm storage and handling, slurry transport, and mixing all involve multiphase flow dynamics, which require an improved understanding of the mechanisms responsible for rheological changes in non-Newtonian multiphase slurries (NNMS). To discuss the issues in predicting the behavior of NNMS, the workshop focused on two topic areas: (1) State-of-the-art in non-Newtonian Multiphase Slurry Flow, and (2) Scaling up with Confidence and Ensuring Safe and Reliable Long-Term Operation.

  9. Annual Logging Symposium, June 21-24, 2009 HISTORY MATCHING OF MULTIPHASE-FLOW FORMATION-

    E-Print Network [OSTI]

    Torres-Verdín, Carlos

    SPWLA 50th Annual Logging Symposium, June 21-24, 2009 1 HISTORY MATCHING OF MULTIPHASE-phase analytical techniques. We describe the successful application of a three- dimensional (3D) multiphase

  10. A MultiPhase Power Flow Model for Grid Analysis A. P. Sakis Meliopoulos

    E-Print Network [OSTI]

    A MultiPhase Power Flow Model for µµµµGrid Analysis A. P. Sakis Meliopoulos School of Electrical multiphase power flow analysis method that provides exact solution to the operation of the µGrid under steady

  11. International Conference on Multiphase Flow, ICMF 2010, Tampa, FL, May 30 June 4, 2010

    E-Print Network [OSTI]

    Dabiri, John O.

    7th International Conference on Multiphase Flow, ICMF 2010, Tampa, FL, May 30 ­ June 4, 2010 Shock Conference on Multiphase Flow, ICMF 2010, Tampa, FL, May 30 ­ June 4, 2010 Us Shock speed (m s-1 ) x Spatial

  12. Performance Evaluation and CFD Simulation of Multiphase Twin-Screw Pumps 

    E-Print Network [OSTI]

    Patil, Abhay

    2013-05-16T23:59:59.000Z

    Twin-screw pumps are economical alternatives to the conventional multiphase system and are increasingly used in the oil and gas industry due to their versatility in transferring the multiphase mixture with varying Gas Void Fraction (GVF). Present...

  13. National laboratories` capabilities summaries for the DOE Virtual Center for Multiphase Dynamics (VCMD)

    SciTech Connect (OSTI)

    Joyce, E.L.

    1997-03-01T23:59:59.000Z

    The Virtual Center For Multiphase Dynamics (VCMD) integrates and develops the resources of industry, government, academia, and professional societies to enable reliable analysis in multiphase computational fluid dynamics. The primary means of the VCMD focus will be by the creation, support, and validation of a computerized simulation capability for multiphase flow and multiphase flow applications. This paper briefly describes the capabilities of the National Laboratories in this effort.

  14. Multiphase electropatterning of cells and biomaterials{ Dirk R. Albrecht,{a

    E-Print Network [OSTI]

    Bhatia, Sangeeta

    Multiphase electropatterning of cells and biomaterials{ Dirk R. Albrecht,{a Gregory H. Underhill that permit efficient dielectrophoretic patterning. Here, we resolve this issue by forming multiphase tissues multiphase tissues with microscale architecture that combine high local hydrogel conductivity for enhanced

  15. Generalized Steady-state Analysis of Multiphase Interleaved Boost Converter with Coupled Inductors

    E-Print Network [OSTI]

    Lipo, Thomas

    2005-38 Generalized Steady-state Analysis of Multiphase Interleaved Boost Converter with Coupled-dong, Masan, Gyeongnam, 631-701, Republic of Korea #12;Generalised steady-state analysis of multiphase.A. Lipo Abstract: The generalised steady-state analysis of the multi-phase interleaved boost converter

  16. Computational Fluids Dynamics and its Application to Multiphase Flows (3 credits)

    E-Print Network [OSTI]

    Chen, Zheng

    Computational Fluids Dynamics and its Application to Multiphase Flows (3 credits) Instructor Eric CLIMENT, Dept. of Fluids Mechanics, INP-ENSEEIHT / IMFT (eric.climent@imft.fr) Synopsis Multiphase flows will be introduced, together with their applications to multiphase flows (dispersion, two-way coupling, modelling

  17. Digitally Controlled Distributed Multiphase DC-DC Converters Xu Zhang, Luca Corradini and Dragan Maksimovic

    E-Print Network [OSTI]

    Digitally Controlled Distributed Multiphase DC-DC Converters Xu Zhang, Luca Corradini and Dragan, corradin, maksimov}@colorado.edu Abstract -- This paper describes a distributed master-slave multiphase DC V-to-12 V input, 1.3 V, 20 A output two-phase synchronous buck converter. Index Terms-- Multiphase

  18. Excitation of multiphase waves of the nonlinear Schrdinger equation by capture into resonances L. Friedland*

    E-Print Network [OSTI]

    Friedland, Lazar

    Excitation of multiphase waves of the nonlinear Schrödinger equation by capture into resonances L; published 14 March 2005 A method for adiabatic excitation and control of multiphase N-band waves is illustrated in simulations, where the excited multiphase waves are analyzed via the spectral approach

  19. Emergence and Control of Multiphase Nonlinear Waves by Synchronization L. Friedland1

    E-Print Network [OSTI]

    Friedland, Lazar

    Emergence and Control of Multiphase Nonlinear Waves by Synchronization L. Friedland1 and A. G 2003) Large amplitude multiphase solutions of the periodic Korteweg­de Vries equation are excited multiphase self-locking of the system with eikonal-type perturbations. The synchronization of each phase

  20. Comment on "A Look at the Multiphase Mixture Model for PEM Fuel Cell Simulations"

    E-Print Network [OSTI]

    Comment on "A Look at the Multiphase Mixture Model for PEM Fuel Cell Simulations" [Electrochem received June 2, 2008. Published December 11, 2008. The article of Gurau et al.1 discusses the multiphase mixture M2 model developed by Wang and co-workers2-6 over the last 15 years for the modeling of multiphase

  1. IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 23, NO. 4, JULY 2008 2201 Scalable Digital Multiphase Modulator

    E-Print Network [OSTI]

    IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 23, NO. 4, JULY 2008 2201 Scalable Digital Multiphase, IEEE Abstract--An architecture is presented for digital multiphase modulators (MPM) that leads Terms--Converter, digital, electronics, integrated cir- cuit (IC), modulator, multiphase, power

  2. Multiphase control of a nonlinear lattice M. Khasin and L. Friedland

    E-Print Network [OSTI]

    Friedland, Lazar

    Multiphase control of a nonlinear lattice M. Khasin and L. Friedland Racah Institute of Physics Large amplitude, multiphase excitations of the periodic Toda lattice (n-gap solutions are created multiphase self-locking of the system with adiabatic wavelike perturbations. The synchronization of each

  3. Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal fluid flow

    E-Print Network [OSTI]

    Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal studies addressing the effects of multiphase flow on crustal mechanics have been attempted. Recent numerical simulations of multiphase (liquid-gas), multicomponent (H2O­CO2) hydrothermal fluid flow

  4. MSTS - Multiphase Subsurface Transport Simulator theory manual

    SciTech Connect (OSTI)

    White, M.D.; Nichols, W.E.

    1993-05-01T23:59:59.000Z

    The US Department of Energy, through the Yucca Mountain Site Characterization Project Office, has designated the Yucca Mountain site in Nevada for detailed study as the candidate US geologic repository for spent nuclear fuel and high-level radioactive waste. Site characterization will determine the suitability of the Yucca Mountain site for the potential waste repository. If the site is determined suitable, subsequent studies and characterization will be conducted to obtain authorization from the Nuclear Regulatory Commission to construct the potential waste repository. A principal component of the characterization and licensing processes involves numerically predicting the thermal and hydrologic response of the subsurface environment of the Yucca Mountain site to the potential repository over a 10,000-year period. The thermal and hydrologic response of the subsurface environment to the repository is anticipated to include complex processes of countercurrent vapor and liquid migration, multiple-phase heat transfer, multiple-phase transport, and geochemical reactions. Numerical simulators based on mathematical descriptions of these subsurface phenomena are required to make numerical predictions of the thermal and hydrologic response of the Yucca Mountain subsurface environment The engineering simulator called the Multiphase Subsurface Transport Simulator (MSTS) was developed at the request of the Yucca Mountain Site Characterization Project Office to produce numerical predictions of subsurface flow and transport phenomena at the potential Yucca Mountain site. This document delineates the design architecture and describes the specific computational algorithms that compose MSTS. Details for using MSTS and sample problems are given in the {open_quotes}User`s Guide and Reference{close_quotes} companion document.

  5. Development of Next Generation Multiphase Pipe Flow Prediction Tools

    SciTech Connect (OSTI)

    Cem Sarica; Holden Zhang

    2006-05-31T23:59:59.000Z

    The developments of oil and gas fields in deep waters (5000 ft and more) will become more common in the future. It is inevitable that production systems will operate under multiphase flow conditions (simultaneous flow of gas, oil and water possibly along with sand, hydrates, and waxes). Multiphase flow prediction tools are essential for every phase of hydrocarbon recovery from design to operation. Recovery from deep-waters poses special challenges and requires accurate multiphase flow predictive tools for several applications, including the design and diagnostics of the production systems, separation of phases in horizontal wells, and multiphase separation (topside, seabed or bottom-hole). It is crucial for any multiphase separation technique, either at topside, seabed or bottom-hole, to know inlet conditions such as flow rates, flow patterns, and volume fractions of gas, oil and water coming into the separation devices. Therefore, the development of a new generation of multiphase flow predictive tools is needed. The overall objective of the proposed study is to develop a unified model for gas-oil-water three-phase flow in wells, flow lines, and pipelines to predict flow characteristics such as flow patterns, phase distributions, and pressure gradient encountered during petroleum production at different flow conditions (pipe diameter and inclination, fluid properties and flow rates). In the current multiphase modeling approach, flow pattern and flow behavior (pressure gradient and phase fractions) prediction modeling are separated. Thus, different models based on different physics are employed, causing inaccuracies and discontinuities. Moreover, oil and water are treated as a pseudo single phase, ignoring the distinct characteristics of both oil and water, and often resulting in inaccurate design that leads to operational problems. In this study, a new model is being developed through a theoretical and experimental study employing a revolutionary approach. The basic continuity and momentum equations is established for each phase, and used for both flow pattern and flow behavior predictions. The required closure relationships are being developed, and will be verified with experimental results. Gas-oil-water experimental studies are currently underway for the horizontal pipes. Industry-driven consortia provide a cost-efficient vehicle for developing, transferring, and deploying new technologies into the private sector. The Tulsa University Fluid Flow Projects (TUFFP) is one of the earliest cooperative industry-university research consortia. TUFFP's mission is to conduct basic and applied multiphase flow research addressing the current and future needs of hydrocarbon production and transportation. TUFFP participants and The University of Tulsa are supporting this study through 55% cost sharing.

  6. Abstract--A new architecture is proposed for digital multiphase modulators that leads to a natural hardware

    E-Print Network [OSTI]

    Abstract-- A new architecture is proposed for digital multiphase modulators that leads to a natural resolution.. I. INTRODUCTION A high performance multiphase modulator (MPM) is an essential component in multi-phase an area efficient and versatile interface between a digital command and a multi-phase DC-DC converter

  7. Guidance Document Reactive Chemicals

    E-Print Network [OSTI]

    showers and chillers. Health Hazards: The reactive chemicals are grouped primarily because of the physical

  8. Groundwater Reactive Transport Models, 2012, 141-159 141 Fan Zhang, Gour-Tsyh (George) Yeh, Jack C. Parker and Xiaonan Shi (Eds)

    E-Print Network [OSTI]

    Mills, Richard

    performance computing, reactive transport, carbon sequestration, multiple realizations, multiphase flow transport at the Hanford 300 Area and CO2 sequestration in deep geologic formations. Keywords: High resources, such as CO2 sequestration in deep geologic formations, on the environment, and the efficacy

  9. Multiphase Flow Modeling of Biofuel Production Processes

    SciTech Connect (OSTI)

    D. Gaston; D. P. Guillen; J. Tester

    2011-06-01T23:59:59.000Z

    As part of the Idaho National Laboratory's (INL's) Secure Energy Initiative, the INL is performing research in areas that are vital to ensuring clean, secure energy supplies for the future. The INL Hybrid Energy Systems Testing (HYTEST) Laboratory is being established to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. HYTEST involves producing liquid fuels in a Hybrid Energy System (HES) by integrating carbon-based (i.e., bio-mass, oil-shale, etc.) with non-carbon based energy sources (i.e., wind energy, hydro, geothermal, nuclear, etc.). Advances in process development, control and modeling are the unifying vision for HES. This paper describes new modeling tools and methodologies to simulate advanced energy processes. Needs are emerging that require advanced computational modeling of multiphase reacting systems in the energy arena, driven by the 2007 Energy Independence and Security Act, which requires production of 36 billion gal/yr of biofuels by 2022, with 21 billion gal of this as advanced biofuels. Advanced biofuels derived from microalgal biomass have the potential to help achieve the 21 billion gal mandate, as well as reduce greenhouse gas emissions. Production of biofuels from microalgae is receiving considerable interest due to their potentially high oil yields (around 600 gal/acre). Microalgae have a high lipid content (up to 50%) and grow 10 to 100 times faster than terrestrial plants. The use of environmentally friendly alternatives to solvents and reagents commonly employed in reaction and phase separation processes is being explored. This is accomplished through the use of hydrothermal technologies, which are chemical and physical transformations in high-temperature (200-600 C), high-pressure (5-40 MPa) liquid or supercritical water. Figure 1 shows a simplified diagram of the production of biofuels from algae. Hydrothermal processing has significant advantages over other biomass processing methods with respect to separations. These 'green' alternatives employ a hybrid medium that, when operated supercritically, offers the prospect of tunable physicochemical properties. Solubility can be rapidly altered and phases partitioned selectively to precipitate or dissolve certain components by altering temperature or pressure in the near-critical region. The ability to tune the solvation properties of water in the highly compressible near-critical region facilitates partitioning of products or by-products into separate phases to separate and purify products. Since most challenges related to lipid extraction are associated with the industrial scale-up of integrated extraction systems, the new modeling capability offers the prospect of addressing previously untenable scaling issues.

  10. Excitation and control of multi-phase periodic waves in

    E-Print Network [OSTI]

    Fominov, Yakov

    the phase of the excited wave by the driver ("phase-locking") control the wave by varying parametersExcitation and control of multi-phase periodic waves in sine-Gordon equation Arkadiy Shagalovµcr U ()eff U ()eff Threshold condition for phase-locking: µ > µcr = 0.41 > cr = 3.28 3/2 0m 3

  11. Benchmark ExperimentalDatabase for Multiphase Combustion Model

    E-Print Network [OSTI]

    Magee, Joseph W.

    Benchmark ExperimentalDatabase for Multiphase Combustion Model Input and Validation: Baseline Doppler Interferometer 2.3. FourierTransformInfrared Spectrometer Spray CombustionReactor -Baseline Case 3 for the combustion airflowrate (56.7m3h-'). Table 5. The locations and mean values of the wall temperatures. Table 6

  12. Model Predictive Control of Variable Density Multiphase Flows Governed by

    E-Print Network [OSTI]

    Hinze, Michael

    of model predictive control (MPC) consists in steering or keeping the state of a dynamical systemModel Predictive Control of Variable Density Multiphase Flows Governed by Diffuse Interface Models appearing in the model predictive control strategy. The resulting control concept is known as instantaneous

  13. CONTINUOUSTIME FINITE ELEMENT ANALYSIS OF MULTIPHASE FLOW IN GROUNDWATER HYDROLOGY

    E-Print Network [OSTI]

    CONTINUOUS­TIME FINITE ELEMENT ANALYSIS OF MULTIPHASE FLOW IN GROUNDWATER HYDROLOGY Zhangxin Chen­water system in groundwater hydrology is given. The system is written in a fractional flow formulation, i for an air­water system in groundwater hydrology, ff = a; w [1], [11], [26]: @(OEae ff s ff ) @t +r \\Delta

  14. Multiphase modeling of tumor growth with matrix remodeling and fibrosis

    E-Print Network [OSTI]

    Andrea Tosin; Luigi Preziosi

    2009-10-26T23:59:59.000Z

    We present a multiphase mathematical model for tumor growth which incorporates the remodeling of the extracellular matrix and describes the formation of fibrotic tissue by tumor cells. We also detail a full qualitative analysis of the spatially homogeneous problem, and study the equilibria of the system in order to characterize the conditions under which fibrosis may occur.

  15. A mixed-dimensional finite volume method for multiphase flow

    E-Print Network [OSTI]

    Cirpka, Olaf Arie

    ; Numerical reservoir simulation; Fractured reser- voir; Mixed-dimensional Finite Volume Method; MultigridA mixed-dimensional finite volume method for multiphase flow in fractured porous media Volker method for the fully coupled, fully implicit discretization of two-phase flow in fractured porous media

  16. Applying uncertainty quantification to multiphase flow computational fluid dynamics

    SciTech Connect (OSTI)

    Gel, A.; Garg, R.; Tong, C.; Shahnam, M.; Guenther, C.

    2013-07-01T23:59:59.000Z

    Multiphase computational fluid dynamics plays a major role in design and optimization of fossil fuel based reactors. There is a growing interest in accounting for the influence of uncertainties associated with physical systems to increase the reliability of computational simulation based engineering analysis. The U.S. Department of Energy's National Energy Technology Laboratory (NETL) has recently undertaken an initiative to characterize uncertainties associated with computer simulation of reacting multiphase flows encountered in energy producing systems such as a coal gasifier. The current work presents the preliminary results in applying non-intrusive parametric uncertainty quantification and propagation techniques with NETL's open-source multiphase computational fluid dynamics software MFIX. For this purpose an open-source uncertainty quantification toolkit, PSUADE developed at the Lawrence Livermore National Laboratory (LLNL) has been interfaced with MFIX software. In this study, the sources of uncertainty associated with numerical approximation and model form have been neglected, and only the model input parametric uncertainty with forward propagation has been investigated by constructing a surrogate model based on data-fitted response surface for a multiphase flow demonstration problem. Monte Carlo simulation was employed for forward propagation of the aleatory type input uncertainties. Several insights gained based on the outcome of these simulations are presented such as how inadequate characterization of uncertainties can affect the reliability of the prediction results. Also a global sensitivity study using Sobol' indices was performed to better understand the contribution of input parameters to the variability observed in response variable.

  17. PAPER 2004-277 A Multiphase Flow Approach to Modelling

    E-Print Network [OSTI]

    Wan, Richard G.

    1 PAPER 2004-277 A Multiphase Flow Approach to Modelling Sand Production using Finite Elements R is to be presented at the Petroleum Society's 5th Canadian International Petroleum Conference (55th Annual Technical of the meeting. This paper and any discussion filed will be considered for publication in Petroleum Society

  18. Albany, OR * Anchorage, AK * Morgantown...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    - is developing a comprehensive reservoir simulator for modeling non-isothermal multiphase flow and transport of CO 2 in saline aquifers under varying temperature and pressure...

  19. Corrosion-induced gas generation in a nuclear waste repository: Reactive geochemistry and multiphase flow effect

    E-Print Network [OSTI]

    Xu, T.

    2009-01-01T23:59:59.000Z

    conditions. The kinetic rate expression is given in the next6 of 6 2.2. Kinetic Rate Expression Similar to dissolution

  20. Multiphase flow and multicomponent reactive transport model of the ventilation experiment in Opalinus clay

    E-Print Network [OSTI]

    Zheng, L.

    2010-01-01T23:59:59.000Z

    experiment in Opalinus Clay for the management ofconductivity of the Opalinus clay at a regional scale:1953. Adsorption studies on clay minerals. II. A formulation

  1. Numerical Modeling of Reactive Multiphase Flow for FCC and Hot Gas Desulfurization Circulating Fluidized Beds

    SciTech Connect (OSTI)

    None

    2005-07-01T23:59:59.000Z

    This work was carried out to understand the behavior of the solid and gas phases in a CFB riser. Only the riser is modeled as a straight pipe. A model with linear algebraic approximation to solids viscosity of the form, {musubs} = 5.34{epsisubs}, ({espisubs} is the solids volume fraction) with an appropriate boundary condition at the wall obtained by approximate momentum balance solution at the wall to acount for the solids recirculation is tested against experimental results. The work done was to predict the flow patterns in the CFB risers from available experimental data, including data from a 7.5-cm-ID CFB riser at the Illinois Institute of Technology and data from a 20.0-cm-ID CFB riser at the Particulate Solid Research, Inc., facility. This research aims at modeling the removal of hydrogen sulfide from hot coal gas using zinc oxide as the sorbent in a circulating fluidized bed and in the process indentifying the parameters that affect the performance of the sulfidation reactor. Two different gas-solid reaction models, the unreacted shrinking core (USC) and the grain model were applied to take into account chemical reaction resistances. Also two different approaches were used to affect the hydrodynamics of the process streams. The first model takes into account the effect of micro-scale particle clustering by adjusting the gas-particle drag law and the second one assumes a turbulent core with pseudo-steady state boundary condition at the wall. A comparison is made with experimental results.

  2. REACTIVE MULTIPHASE BEHAVIOR OF CO2 IN SALINE AQUIFERS BENEATH THE COLORADO PLATEAU

    SciTech Connect (OSTI)

    R.G. Allis; J. Moore; S. White

    2003-06-30T23:59:59.000Z

    The six coal-fired power plants located in the Colorado Plateau and southern Rocky Mountain region of the U.S. produce 100 million tons of CO{sub 2} per year. Thick sequences of collocated sedimentary rocks represent potential sites for sequestration of the CO{sub 2}. Field and laboratory investigations of naturally occurring CO{sub 2}-reservoirs are being conducted to determine the characteristics of potential seal and reservoir units and the extent of the interactions that occur between the host rocks and the CO{sub 2} charged fluids. The results are being incorporated into a series of two-dimensional numerical models that represent the major chemical and physical processes induced by injection. During reporting period covered here (March 30 to June 30, 2003), the main achievements were: Presentation of three papers at the Second Annual Conference on Carbon Sequestration (May 5-8, Alexandria, Virginia); Presentation of a poster at the American Association of Petroleum Geologists meeting; Co-PI organized and chaired a special session on Geologic Carbon Dioxide Sequestration at the American Association of Petroleum Geologists annual convention in Salt Lake City (May 12-15).

  3. Multiphase flow and multicomponent reactive transport model of the ventilation experiment in Opalinus clay

    E-Print Network [OSTI]

    Zheng, L.

    2010-01-01T23:59:59.000Z

    Samper, J. , Zheng, L. , Montenegro, L. , 2006c. CoupledSamper, J. , Zheng, L. , Montenegro, L. , Fernández, A.M. ,A.M. Fernández and L. Montenegro, 2008b, Inverse modeling of

  4. Corrosion-induced gas generation in a nuclear waste repository: Reactive geochemistry and multiphase flow effect

    E-Print Network [OSTI]

    Xu, T.

    2009-01-01T23:59:59.000Z

    L.W. 1982. Factors affecting the corrosion of metals inatmosphere, Atmospheric Corrosion, Ed. W.H. Ailov, New York.P. , Minet, Y. 2007. Iron corrosion in Callovo–Oxfordian

  5. System for reactivating catalysts

    DOE Patents [OSTI]

    Ginosar, Daniel M. (Idaho Falls, ID); Thompson, David N. (Idaho Falls, ID); Anderson, Raymond P. (Idaho Falls, ID)

    2010-03-02T23:59:59.000Z

    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.

  6. WATER RESOURCES RESEARCH, VOL. 29, NO. 11, PAGES 3727-3740, NOVEMBER 1993 Modeling of Multiphase Transport of Multicomponent Organic Contaminants

    E-Print Network [OSTI]

    Patzek, Tadeusz W.

    WATER RESOURCES RESEARCH, VOL. 29, NO. 11, PAGES 3727-3740, NOVEMBER 1993 Modeling of Multiphase, Berkeley A numerical compositionalsimulator (Multiphase Multicomponent Nonisothermal Organics Trans- portSimulator(M2NOTS))hasbeendevelopedformodelingtransient,three-dimensional,noniso- thermal, and multiphase

  7. Impact of wettability correlations on multiphase flow through porous media

    E-Print Network [OSTI]

    Marta S. de La Lama; Martin Brinkmann

    2012-05-31T23:59:59.000Z

    In the last decades, significant progress has been made in understanding the multiphase displacement through porous media with homogeneous wettability and its relation to the pore geometry. However, the role of wettability at the scale of the pore remains still little understood. In the present study the displacement of immiscible fluids through a two-dimensional porous medium is simulated by means of a mesoscopic particle approach. The substrate is described as an assembly of non-overlapping circular disks whose preferential wettability is distributed according to prescribed spatial correlations, from pore scale up to domains at system size. We analyze how this well-defined heterogeneous wettability affects the flow and try to establish a relationship among wettability-correlations and large-scale properties of the multiphase flow.

  8. Method for producing nanocrystalline multicomponent and multiphase materials

    DOE Patents [OSTI]

    Eastman, Jeffrey A. (Woodridge, IL); Rittner, Mindy N. (Des Plaines, IL); Youngdahl, Carl J. (Westmont, IL); Weertman, Julia R. (Evanston, IL)

    1998-01-01T23:59:59.000Z

    A process for producing multi-component and multiphase nanophase materials is provided wherein a plurality of elements are vaporized in a controlled atmosphere, so as to facilitate thorough mixing, and then condensing and consolidating the elements. The invention also provides for a multicomponent and multiphase nanocrystalline material of specified elemental and phase composition having component grain sizes of between approximately 1 nm and 100 nm. This material is a single element in combination with a binary compound. In more specific embodiments, the single element in this material can be a transition metal element, a non-transition metal element, a semiconductor, or a semi-metal, and the binary compound in this material can be an intermetallic, an oxide, a nitride, a hydride, a chloride, or other compound.

  9. System for measuring multiphase flow using multiple pressure differentials

    DOE Patents [OSTI]

    Fincke, James R. (Idaho Falls, ID)

    2003-01-01T23:59:59.000Z

    An improved method and system for measuring a multi-phase flow in a pressure flow meter. An extended throat venturi is used and pressure of the multi-phase flow is measured at three or more positions in the venturi, which define two or more pressure differentials in the flow conduit. The differential pressures are then used to calculate the mass flow of the gas phase, the total mass flow, and the liquid phase. The system for determining the mass flow of the high void fraction fluid flow and the gas flow includes taking into account a pressure drop experienced by the gas phase due to work performed by the gas phase in accelerating the liquid phase.

  10. Method for producing nanocrystalline multicomponent and multiphase materials

    DOE Patents [OSTI]

    Eastman, J.A.; Rittner, M.N.; Youngdahl, C.J.; Weertman, J.R.

    1998-03-17T23:59:59.000Z

    A process for producing multi-component and multiphase nanophase materials is provided wherein a plurality of elements are vaporized in a controlled atmosphere, so as to facilitate thorough mixing, and then condensing and consolidating the elements. The invention also provides for a multicomponent and multiphase nanocrystalline material of specified elemental and phase composition having component grain sizes of between approximately 1 nm and 100 nm. This material is a single element in combination with a binary compound. In more specific embodiments, the single element in this material can be a transition metal element, a non-transition metal element, a semiconductor, or a semi-metal, and the binary compound in this material can be an intermetallic, an oxide, a nitride, a hydride, a chloride, or other compound. 6 figs.

  11. The Baryon Catastrophe and the multiphase intracluster medium

    E-Print Network [OSTI]

    K. F. Gunn; P. A. Thomas

    1995-10-17T23:59:59.000Z

    We review the theories and observations which together have led to the concept of the Baryon Catastrophe: observations of the baryon fraction on the scale of clusters of galaxies appear to be at least three times as high as the universal baryon fraction predicted by the theory of primordial nucleosynthesis in a flat, $\\Omega_0 = 1$, universe. We investigate whether this discrepancy could be eliminated by treating the intracluster gas as a multiphase medium, and find that this treatment both lowers the calculated mass of gas in a cluster and increases the inferred gravitational potential. These combined effects can reduce the calculated baryon fraction by between a quarter and a half: the precise amount depends upon the volume fraction distribution of density phases in the gas but is independent of the temperature profile across the cluster. Thus moving to a multiphase intracluster medium cannot resolve the Baryon Catastrophe by itself; other possible causes and explanations are discussed.

  12. In-situ formation of multiphase deposited thermal barrier coatings

    DOE Patents [OSTI]

    Subramanian, Ramesh

    2004-01-13T23:59:59.000Z

    A multiphase ceramic thermal barrier coating is provided. The coating is adapted for use in high temperature applications in excess of about 1200.degree. C., for coating superalloy components of a combustion turbine engine. The coating comprises a ceramic single or two oxide base layer disposed on the substrate surface; and a ceramic oxide reaction product material disposed on the base layer, the reaction product comprising the reaction product of the base layer with a ceramic single or two oxide overlay layer.

  13. Multiphase transport model for heavy ion collisions at RHIC

    E-Print Network [OSTI]

    Zi-wei Lin; Subrata Pal; C. M. Ko; Bao-An Li; Bin Zhang

    2001-05-18T23:59:59.000Z

    Using a multiphase transport model (AMPT) with both partonic and hadronic interactions, we study the multiplicity and transverse momentum distributions of charged particles such as pions, kaons and protons in central Au+Au collisions at RHIC energies. Effects due to nuclear shadowing and jet quenching on these observables are also studied. We further show preliminary results on the production of multistrange baryons from the strangeness-exchange reactions during the hadronic stage of heavy ion collisions.

  14. Thermographic analysis of turbulent non-isothermal water boundary layer

    E-Print Network [OSTI]

    Znamenskaya, Irina A

    2015-01-01T23:59:59.000Z

    The paper is devoted to the investigation of the turbulent water boundary layer in the jet mixing flows using high-speed infrared (IR) thermography. Two turbulent mixing processes were studied: a submerged water jet impinging on a flat surface and two intersecting jets in a round disc-shaped vessel. An infrared camera (FLIR Systems SC7700) was focused on the window transparent for IR radiation; it provided high-speed recordings of heat fluxes from a thin water layer close to the window. Temperature versus time curves at different points of water boundary layer near the wall surface were acquired using the IR camera with the recording frequency of 100 Hz. The time of recording varied from 3 till 20 min. The power spectra for the temperature fluctuations at different points on the hot-cold water mixing zone were calculated using the Fast Fourier Transform algorithm. The obtained spectral behavior was compared to the Kolmogorov "-5/3 spectrum" (a direct energy cascade) and the dual-cascade scenario predicted for...

  15. Multiphase fluid flow and time lapse seismics UNLP, 11 Octubre de ...

    E-Print Network [OSTI]

    santos

    Time-lapse seismic surveys aim to monitor the migration and dispersal of the CO2 plume after injection. Multiphase fluid flow and time lapse seismics – p. 3 ...

  16. A posteriori error estimates with application of adaptive mesh refinement for thermal multiphase compositional flows in porous

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of diffusive fluxes. Numerical results on an example of real-life thermal oil-recovery in a reservoir refinement, compositional Darcy flow, thermal flow, finite volume method 1 Introduction The thermal under a non-isothermal condition. The governing equations are the conservation of the amount of each

  17. A Multiphase Model for Cold Start of Polymer Electrolyte Fuel Leng Mao, Chao-Yang Wang,*,z

    E-Print Network [OSTI]

    A Multiphase Model for Cold Start of Polymer Electrolyte Fuel Cells Leng Mao, Chao-Yang Wang, The Pennsylvania State University, University Park, Pennsylvania 16802, USA A multiphase and transient model

  18. Experimental investigation of the use of drag reducing agents in conjunction with twin-screw multiphase pumps

    E-Print Network [OSTI]

    Carrillo Plazas, Gabriel D

    2000-01-01T23:59:59.000Z

    Application of multiphase technology has accelerated over the past decade. The development of this technology has been driven by the challenges to economically produce from deepwater and other remote objectives. Both multiphase pumping and the use...

  19. Experimental investigation of the use of drag reducing agents in conjunction with twin-screw multiphase pumps 

    E-Print Network [OSTI]

    Carrillo Plazas, Gabriel D

    2000-01-01T23:59:59.000Z

    Application of multiphase technology has accelerated over the past decade. The development of this technology has been driven by the challenges to economically produce from deepwater and other remote objectives. Both multiphase pumping and the use...

  20. Fast, Streaming 3D Levelset on the GPU for Smooth Multi-phase Segmentation

    E-Print Network [OSTI]

    Texas at Austin, University of

    Fast, Streaming 3D Levelset on the GPU for Smooth Multi-phase Segmentation Ojaswa Sharma1 , Qin at Austin, Austin, Texas, 78712-0027, USA {zqyork@ices,bajaj@cs}.utexas.edu Abstract. Level set method based. We show vol- umetric segmentation using higher order, multi-phase level set method with speedups

  1. Modeling of wet gas compression in twin-screw multiphase pump

    E-Print Network [OSTI]

    Xu, Jian

    2009-05-15T23:59:59.000Z

    Fig. 1.4 Subsea multiphase pumping system in Ceiba Field, West Africa............................................................... 8 Fig. 1.5 Twin-screw pump cutaway ............................................................... 12 Fig... Page Table 1.1 Summary of subsea multiphase pumping projects............................ 9 Table 1.2 Summary of subsea wet gas compression projects ........................... 10 Table 2.1 Summary of current models for twin-screw pump...

  2. Analytical Model of Magnet Eddy-Current Volume Losses in Multi-phase PM Machines

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Analytical Model of Magnet Eddy-Current Volume Losses in Multi-phase PM Machines with Concentrated, 94000 Créteil France Abstract--this paper studies magnet eddy-current losses in permanent magnet (PM calculations. Keywords--Traction, Concentrated Winding, Eddy- Current, Volume Magnet Losses, Multiphase Machine

  3. A posteriori error estimates, stopping criteria, and adaptivity for multiphase compositional Darcy flows in porous media

    E-Print Network [OSTI]

    A posteriori error estimates, stopping criteria, and adaptivity for multiphase compositional Darcy derive a posteriori error estimates for the compositional model of multiphase Darcy flow in porous media, consisting of a system of strongly coupled nonlinear unsteady partial differential and algebraic equations

  4. An energy preserving formulation for the simulation of multiphase turbulent flows.

    E-Print Network [OSTI]

    Fuster, Daniel

    An energy preserving formulation for the simulation of multiphase turbulent flows. Abstract In this manuscript we propose an energy preserving formulation for the simulation of multiphase flows. The new jumps across the interface including surface tension effects. 1 Introduction Nowadays the simulation

  5. A Fault-Tolerant Multiphase Permanent Magnet Generator for Marine Current Turbine Applications

    E-Print Network [OSTI]

    Boyer, Edmond

    A Fault-Tolerant Multiphase Permanent Magnet Generator for Marine Current Turbine Applications on offshore wind turbine systems. Marine current turbines are characterized by a very difficult access feature. This paper deals with the use of a PM multiphase marine current turbine generator. With this kind

  6. A high-resolution mapped grid algorithm for compressible multiphase flow problems

    E-Print Network [OSTI]

    Shyue, Keh-Ming

    A high-resolution mapped grid algorithm for compressible multiphase flow problems K.-M. Shyue 18 August 2010 Keywords: Compressible multiphase flow Fluid-mixture model Mapped grids Wave-propagation method Stiffened gas equation of state a b s t r a c t We describe a simple mapped-grid approach

  7. A high-resolution mapped grid algorithm for compressible multiphase flow problems

    E-Print Network [OSTI]

    Shyue, Keh-Ming

    A high-resolution mapped grid algorithm for compressible multiphase flow problems K.-M. Shyue mapped grid approach for the efficient numerical simula- tion of compressible multiphase flow in general problems, J. Comput. Phys. 142 (1998) 208-242). A standard high-resolution mapped grid method in wave

  8. An On-line Method for Stator Fault Detection in Multi-phase PMSM Drives

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    An On-line Method for Stator Fault Detection in Multi-phase PMSM Drives Fabien Meinguet*, Eric deals with an on-line fault detection method for multi-phase PMSM drives. The method is based an original method for detecting an abnormal asymmetrical behavior in five-phase PMSM drives and we apply

  9. Pore-scale characteristics of multiphase flow in porous media: A comparison of airwater and oilwater experiments

    E-Print Network [OSTI]

    Wildenschild, Dorthe

    Pore-scale characteristics of multiphase flow in porous media: A comparison of air­water and oil Ltd. All rights reserved. Keywords: Multi-phase flow; NAPLs; Porous media; Microtomography; Interfacial areas; Capillary pressure­saturation curves 1. Introduction Understanding of multiphase flow

  10. Abstract--System modeling and digital control in a modular masterless multiphase architecture are presented in this paper.

    E-Print Network [OSTI]

    Abstract-- System modeling and digital control in a modular masterless multiphase architecture of large load transients. Interleaved multi-phase converters are frequently used in such systems due response and small output capacitance. In general, multi-phase converters require control approaches

  11. Multi-phase back contacts for CIS solar cells

    DOE Patents [OSTI]

    Rockett, A.A.; Yang, L.C.

    1995-12-19T23:59:59.000Z

    Multi-phase, single layer, non-interdiffusing M-Mo back contact metallized films, where M is selected from Cu, Ga, or mixtures thereof, for CIS cells are deposited by a sputtering process on suitable substrates, preferably glass or alumina, to prevent delamination of the CIS from the back contact layer. Typical CIS compositions include CuXSe{sub 2} where X is In or/and Ga. The multi-phase mixture is deposited on the substrate in a manner to provide a columnar microstructure, with micro-vein Cu or/and Ga regions which partially or fully vertically penetrate the entire back contact layer. The CIS semiconductor layer is then deposited by hybrid sputtering and evaporation process. The Cu/Ga-Mo deposition is controlled to produce the single layer two-phase columnar morphology with controllable Cu or Ga vein size less than about 0.01 microns in width. During the subsequent deposition of the CIS layer, the columnar Cu/Ga regions within the molybdenum of the Cu/Ga-Mo back layer tend to partially leach out, and are replaced by columns of CIS. Narrower Cu and/or Ga regions, and those with fewer inner connections between regions, leach out more slowly during the subsequent CIS deposition. This gives a good mechanical and electrical interlock of the CIS layer into the Cu/Ga-Mo back layer. Solar cells employing In-rich CIS semiconductors bonded to the multi-phase columnar microstructure back layer of this invention exhibit vastly improved photo-electrical conversion on the order of 17% greater than Mo alone, improved uniformity of output across the face of the cell, and greater Fill Factor. 15 figs.

  12. Multi-phase back contacts for CIS solar cells

    DOE Patents [OSTI]

    Rockett, Angus A. (505 Park Haven Ct., Champaign, IL 61820); Yang, Li-Chung (1107 W. Green St. #328, Urbana, IL 61801)

    1995-01-01T23:59:59.000Z

    Multi-phase, single layer, non-interdiffusing M-Mo back contact metallized films, where M is selected from Cu, Ga, or mixtures thereof, for CIS cells are deposited by a sputtering process on suitable substrates, preferably glass or alumina, to prevent delamination of the CIS from the back contact layer. Typical CIS compositions include CuXSe.sub.2 where X is In or/and Ga. The multi-phase mixture is deposited on the substrate in a manner to provide a columnar microstructure, with micro-vein Cu or/and Ga regions which partially or fully vertically penetrate the entire back contact layer. The CIS semiconductor layer is then deposited by hybrid sputtering and evaporation process. The Cu/Ga-Mo deposition is controlled to produce the single layer two-phase columnar morphology with controllable Cu or Ga vein size less than about 0.01 microns in width. During the subsequent deposition of the CIS layer, the columnar Cu/Ga regions within the molybdenum of the Cu/Ga-Mo back layer tend to partially leach out, and are replaced by columns of CIS. Narrower Cu and/or Ga regions, and those with fewer inner connections between regions, leach out more slowly during the subsequent CIS deposition. This gives a good mechanical and electrical interlock of the CIS layer into the Cu/Ga-Mo back layer. Solar cells employing In-rich CIS semiconductors bonded to the multi-phase columnar microstructure back layer of this invention exhibit vastly improved photo-electrical conversion on the order of 17% greater than Mo alone, improved uniformity of output across the face of the cell, and greater Fill Factor.

  13. Towards improved methods for determining porous media multiphase flow functions

    E-Print Network [OSTI]

    Xue, Song

    2004-09-30T23:59:59.000Z

    to the empirical relation by using the three-dimensional saturation and relaxation data. 7 CHAPTER II ESTIMATION OF POROUS MEDIA FLOW FUNCTIONS Multiphase flow functions are required to simulate the flow of multiple fluid phases through porous media....3) Snw + Sw = 1: (2.4) Together with boundary and initial conditions, Eqs. (2.1)-(2.4) provide a mathemat- ical model of three-dimensional, two-phase fluid flow in porous media. Several properties have to be specified in the above model. The densities...

  14. Interface effects on multiphase flows in porous media

    SciTech Connect (OSTI)

    Zhang, Duan Z [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    Most models for multiphase flows in a porous medium are based on the straightforward extension of Darcy's law, in which each fluid phase is driven by its own pressure gradient. The pressure difference between the phases is thought to be an effect of surface tension and is called capillary pressure. Independent of Darcy's law, for liquid imbibition processes in a porous material, diffusion models are sometime used. In this paper, an ensemble phase averaging technique for continuous multi phase flows is applied to derive averaged equations and to examine the validity of the commonly used models. The closure for the averaged equations is quite complicated for general multiphase flows in a porous material. For flows with a small ratio of the characteristic length of the phase interfaces to the macroscopic length, the closure relations can be simplified significantly by an approximation with a second order error in the length ratio. The approximation reveals the information of the length scale separation obscured during the ensemble averaging process, and leads to an equation system similar to Darcy's law, but with additional terms. Based on interactions on phase interfaces, relations among closure quantities are studied.

  15. Development of Next Generation Multiphase Pipe Flow Prediction Tools

    SciTech Connect (OSTI)

    Tulsa Fluid Flow

    2008-08-31T23:59:59.000Z

    The developments of fields in deep waters (5000 ft and more) is a common occurrence. It is inevitable that production systems will operate under multiphase flow conditions (simultaneous flow of gas-oil-and water possibly along with sand, hydrates, and waxes). Multiphase flow prediction tools are essential for every phase of the hydrocarbon recovery from design to operation. The recovery from deep-waters poses special challenges and requires accurate multiphase flow predictive tools for several applications including the design and diagnostics of the production systems, separation of phases in horizontal wells, and multiphase separation (topside, seabed or bottom-hole). It is very crucial to any multiphase separation technique that is employed either at topside, seabed or bottom-hole to know inlet conditions such as the flow rates, flow patterns, and volume fractions of gas, oil and water coming into the separation devices. The overall objective was to develop a unified model for gas-oil-water three-phase flow in wells, flow lines, and pipelines to predict the flow characteristics such as flow patterns, phase distributions, and pressure gradient encountered during petroleum production at different flow conditions (pipe diameter and inclination, fluid properties and flow rates). The project was conducted in two periods. In Period 1 (four years), gas-oil-water flow in pipes were investigated to understand the fundamental physical mechanisms describing the interaction between the gas-oil-water phases under flowing conditions, and a unified model was developed utilizing a novel modeling approach. A gas-oil-water pipe flow database including field and laboratory data was formed in Period 2 (one year). The database was utilized in model performance demonstration. Period 1 primarily consisted of the development of a unified model and software to predict the gas-oil-water flow, and experimental studies of the gas-oil-water project, including flow behavior description and closure relation development for different flow conditions. Modeling studies were performed in two parts, Technology Assessment and Model Development and Enhancement. The results of the Technology assessment study indicated that the performance of the current state of the art two-phase flow models was poor especially for three-phase pipeline flow when compared with the existing data. As part of the model development and enhancement study, a new unified model for gas-oil-water three-phase pipe flow was developed. The new model is based on the dynamics of slug flow, which shares transition boundaries with all the other flow patterns. The equations of slug flow are used not only to calculate the slug characteristics, but also to predict transitions from slug flow to other flow patterns. An experimental program including three-phase gas-oil-water horizontal flow and two-phase horizontal and inclined oil-water flow testing was conducted utilizing a Tulsa University Fluid Flow Projects Three-phase Flow Facility. The experimental results were incorporated into the unified model as they became available, and model results were used to better focus and tailor the experimental study. Finally, during the Period 2, a new three-phase databank has been developed using the data generated during this project and additional data available in the literature. The unified model to predict the gas-oil-water three phase flow characteristics was tested by comparing the prediction results with the data. The results showed good agreements.

  16. Multiphase turbulent interstellar medium: some recent results from radio astronomy

    E-Print Network [OSTI]

    Roy, Nirupam

    2015-01-01T23:59:59.000Z

    The radio frequency 1.4 GHz transition of the atomic hydrogen is one of the important tracers of the diffuse neutral interstellar medium. Radio astronomical observations of this transition, using either a single dish telescope or an array interferometer, reveal different properties of the interstellar medium. Such observations are particularly useful to study the multiphase nature and turbulence in the interstellar gas. Observations with multiple radio telescopes have recently been used to study these two closely related aspects in greater detail. Using various observational techniques, the density and the velocity fluctuations in the Galactic interstellar medium was found to have a Kolmogorov-like power law power spectra. The observed power law scaling of the turbulent velocity dispersion with the length scale can be used to derive the true temperature distribution of the medium. Observations from a large ongoing atomic hydrogen absorption line survey have also been used to study the distribution of gas at d...

  17. Convection in multiphase flows using Lattice Boltzmann methods

    E-Print Network [OSTI]

    L. Biferale; P. Perlekar; M. Sbragaglia; F. Toschi

    2011-11-03T23:59:59.000Z

    We present high resolution numerical simulations of convection in multiphase flows (boiling) using a novel algorithm based on a Lattice Boltzmann method. We first validate the thermodynamical and kinematical properties of the algorithm. Then, we perform a series of 3d numerical simulations at changing the mean properties in the phase diagram and compare convection with and without phase coexistence at $Ra \\sim 10^7$. We show that in presence of nucleating bubbles non-Oberbeck Boussinesq effects develops, mean temperature profile becomes asymmetric, heat-transfer and heat-transfer fluctuations are enhanced. We also show that small-scale properties of velocity and temperature fields are strongly affected by the presence of buoyant bubble leading to high non-Gaussian profiles in the bulk.

  18. Iterative methods for solving the pressure problem at multiphase filtration

    E-Print Network [OSTI]

    Vabishchevich, P

    2011-01-01T23:59:59.000Z

    Applied problems of oil and gas recovery are studied numerically using the mathematical models of multiphase fluid flows in porous media. The basic model includes the continuity equations and the Darcy laws for each phase, as well as the algebraic expression for the sum of saturations. Primary computational algorithms are implemented for such problems using the pressure equation. In this paper, we highlight the basic properties of the pressure problem and discuss the necessity of their fulfillment at the discrete level. The resulting elliptic problem for the pressure equation is characterized by a non-selfadjoint operator. Possibilities of approximate solving the elliptic problem are considered using the iterative methods. Special attention is given to the numerical algorithms for calculating the pressure on parallel computers.

  19. A New Multiphase Model for Simulating Energetically Driven Particles

    SciTech Connect (OSTI)

    Stevens, D E; Murphy, M J

    2010-02-02T23:59:59.000Z

    The proper representation of particulate phenomena is important for the simulation of many non-ideal particle loaded explosives. These explosives present severe numerical difficulties to simulate because numerical approaches for packed particle beds often behave poorly for the dilute regime and the reverse is often true for methods developed for the dilute regime. This paper presents a multiphase framework for the simulation of these non-ideal explosives that accurately accounts for the particulate behavior in both of these regimes. The capability of this framework is enhanced by the use of prescribed PDF methods for both particle size distributions and the representation of chemical processes. We have validated this framework using several experimental methods that accommodate the separation of momentum flux measurements in two-phase blast flows.

  20. Multi-Phase Galaxy Formation and Quasar Absorption Systems

    E-Print Network [OSTI]

    Ariyeh H. Maller

    2005-05-06T23:59:59.000Z

    The central problem of galaxy formation is understanding the cooling and condensation of gas in dark matter halos. It is now clear that to match observations this requires further physics than the simple assumptions of single phase gas cooling. A model of multi-phase cooling (Maller & Bullock 2004) can successfully account for the upper cutoff in the masses of galaxies and provides a natural explanation of many types of absorption systems (Mo & Miralda-Escude 1996). Absorption systems are our best probes of the gaseous content of galaxy halos and therefore provide important constraints on models for gas cooling into galaxies. All physical processes that effect gas cooling redistribute gas and therefore are detectable in absorption systems. Detailed studies of the nature of gas in galaxy halos using absorption systems are crucial for building a correct theory of galaxy formation.

  1. Reactive Power Compensator.

    DOE Patents [OSTI]

    El-Sharkawi, M.A.; Venkata, S.S.; Chen, M.; Andexler, G.; Huang, T.

    1992-07-28T23:59:59.000Z

    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.

  2. Reactive power compensator

    DOE Patents [OSTI]

    El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Woodinville, WA); Chen, Mingliang (Kirkland, WA); Andexler, George (Everett, WA); Huang, Tony (Seattle, WA)

    1992-01-01T23:59:59.000Z

    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.

  3. Advanced tomographic flow diagnostics for opaque multiphase fluids

    SciTech Connect (OSTI)

    Torczynski, J.R.; O`Hern, T.J.; Adkins, D.R.; Jackson, N.B.; Shollenberger, K.A.

    1997-05-01T23:59:59.000Z

    This report documents the work performed for the ``Advanced Tomographic Flow Diagnostics for Opaque Multiphase Fluids`` LDRD (Laboratory-Directed Research and Development) project and is presented as the fulfillment of the LDRD reporting requirement. Dispersed multiphase flows, particularly gas-liquid flows, are industrially important to the chemical and applied-energy industries, where bubble-column reactors are employed for chemical synthesis and waste treatment. Due to the large range of length scales (10{sup {minus}6}-10{sup 1}m) inherent in real systems, direct numerical simulation is not possible at present, so computational simulations are forced to use models of subgrid-scale processes, the accuracy of which strongly impacts simulation fidelity. The development and validation of such subgrid-scale models requires data sets at representative conditions. The ideal measurement techniques would provide spatially and temporally resolved full-field measurements of the distributions of all phases, their velocity fields, and additional associated quantities such as pressure and temperature. No technique or set of techniques is known that satisfies this requirement. In this study, efforts are focused on characterizing the spatial distribution of the phases in two-phase gas-liquid flow and in three-phase gas-liquid-solid flow. Due to its industrial importance, the bubble-column geometry is selected for diagnostics development and assessment. Two bubble-column testbeds are utilized: one at laboratory scale and one close to industrial scale. Several techniques for measuring the phase distributions at conditions of industrial interest are examined: level-rise measurements, differential-pressure measurements, bulk electrical impedance measurements, electrical bubble probes, x-ray tomography, gamma-densitometry tomography, and electrical impedance tomography.

  4. Direct numerical simulations of multiphase flow with applications to basaltic volcanism and planetary evolution

    E-Print Network [OSTI]

    Suckale, Jenny

    2011-01-01T23:59:59.000Z

    Multiphase flows are an essential component of natural systems: They affect the explosivity of volcanic eruptions, shape the landscape of terrestrial planets, and govern subsurface flow in hydrocarbon reservoirs. Advancing ...

  5. Patterns of Cognitive Decline in Alzheimer's Dementia: An Application of Hierarchical Bayesian Multiphase Models

    E-Print Network [OSTI]

    Langford, Zachary Denver

    2012-12-31T23:59:59.000Z

    As the Alzheimer's disease process progresses in time measurements of cognitive functioning exhibit nonlinearity. Multiphase models were used to quantify this nonlinearity for thirty-six well characterized individuals(~12 observations per individual...

  6. Effects of buoyancy source composition on multiphase plume behavior in stratification

    E-Print Network [OSTI]

    Chow, Aaron C. (Aaron Chunghin), 1978-

    2004-01-01T23:59:59.000Z

    Experiments are performed where a dense multiphase plume is released vertically in a salinity stratified ambient. The constituent phase composition of the initial buoyancy flux can be dense brine, particles, or a mixture ...

  7. Numerical and analytical studies of single and multiphase starting jets and plumes

    E-Print Network [OSTI]

    Wang, Ruo-Qian

    2014-01-01T23:59:59.000Z

    Multiphase starting jets and plumes are widely observed in nature and engineering systems. An environmental engineering example is open-water disposal of sediments. The present study numerically simulates such starting ...

  8. An unstructured finite volume simulator for multiphase flow through fractured-porous media

    E-Print Network [OSTI]

    Bajaj, Reena

    2009-01-01T23:59:59.000Z

    Modeling of multiphase flow in fractured media plays an integral role in management and performance prediction of oil and gas reserves. Geological characterization and nmultiphase flow simulations in fractured media are ...

  9. Modeling twin-screw multiphase pump performance during periods of high gas volume fraction

    E-Print Network [OSTI]

    Singh, Aditya

    2003-01-01T23:59:59.000Z

    pumping adds energy to an unprocessed effluent stream acting as a combined pump and compressor, permitting the recovery of oil and gas on an economical basis. In practice, multiphase production is characterized by wide fluctuations in the gas and liquid...

  10. Modeling of wet gas compression in twin-screw multiphase pump 

    E-Print Network [OSTI]

    Xu, Jian

    2009-05-15T23:59:59.000Z

    Twin-screw multiphase pumps experience a severe decrease in efficiency, even the breakdown of pumping function, when operating under wet gas conditions. Additionally, field operations have revealed significant vibration and thermal issues which can...

  11. Power Factor Reactive Power

    E-Print Network [OSTI]

    motor power: 117.7 V x 5.1 A = 600 W? = 0.6 kW? NOT the power measured by meter #12;Page 9 PSERC: displacement power factor: angle between voltage and current = 0 degrees pf = cos(0 degrees) = 1.0 true powerPage 1 PSERC Power Factor and Reactive Power Ward Jewell Wichita State University Power Systems

  12. Reactive power compensating system

    DOE Patents [OSTI]

    Williams, Timothy J. (Redondo Beach, CA); El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Seattle, WA)

    1987-01-01T23:59:59.000Z

    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.

  13. Reactive Power Compensating System.

    DOE Patents [OSTI]

    Williams, Timothy J.; El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.

    1985-01-04T23:59:59.000Z

    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.

  14. Experimental characterization of energetic material dynamics for multiphase blast simulation.

    SciTech Connect (OSTI)

    Beresh, Steven Jay; Wagner, Justin L.; Kearney, Sean Patrick; Wright, Elton K.; Baer, Melvin R.; Pruett, Brian Owen Matthew

    2011-09-01T23:59:59.000Z

    Currently there is a substantial lack of data for interactions of shock waves with particle fields having volume fractions residing between the dilute and granular regimes, which creates one of the largest sources of uncertainty in the simulation of energetic material detonation. To close this gap, a novel Multiphase Shock Tube has been constructed to drive a planar shock wave into a dense gas-solid field of particles. A nearly spatially isotropic field of particles is generated in the test section by a gravity-fed method that results in a spanwise curtain of spherical 100-micron particles having a volume fraction of about 19%. Interactions with incident shock Mach numbers of 1.66, 1.92, and 2.02 were achieved. High-speed schlieren imaging simultaneous with high-frequency wall pressure measurements are used to reveal the complex wave structure associated with the interaction. Following incident shock impingement, transmitted and reflected shocks are observed, which lead to differences in particle drag across the streamwise dimension of the curtain. Shortly thereafter, the particle field begins to propagate downstream and spread. For all three Mach numbers tested, the energy and momentum fluxes in the induced flow far downstream are reduced about 30-40% by the presence of the particle field. X-Ray diagnostics have been developed to penetrate the opacity of the flow, revealing the concentrations throughout the particle field as it expands and spreads downstream with time. Furthermore, an X-Ray particle tracking velocimetry diagnostic has been demonstrated to be feasible for this flow, which can be used to follow the trajectory of tracer particles seeded into the curtain. Additional experiments on single spherical particles accelerated behind an incident shock wave have shown that elevated particle drag coefficients can be attributed to increased compressibility rather than flow unsteadiness, clarifying confusing results from the historical database of shock tube experiments. The development of the Multiphase Shock Tube and associated diagnostic capabilities offers experimental capability to a previously inaccessible regime, which can provide unprecedented data concerning particle dynamics of dense gas-solid flows.

  15. Multiphase production through hilly terrain pipelines in Cusiana oilfield, Colombia

    SciTech Connect (OSTI)

    Hill, T.J.; Fairhurst, C.P.; Nelson, C.J.; Becerra, H.; Bailey, R.S.

    1996-12-31T23:59:59.000Z

    The Cusiana oilfield in Colombia is currently producing about 180,000 bpd through a complex multiphase flowline network. The terrain of the area is very hilly, with substantial elevation changes along the length of the lines. Prediction of pressure drop using industry standard correlations has been very variable in its accuracy. A revised pressure drop method, including the effect of slug formation and decay, has been produced, with appreciably better performance. Field data on flow regime characteristics from several of the lines are presented to show a transition from surging/slugging to a steady {open_quote}homogeneous{close_quote} flow at relatively low mixture velocity. The effect of slug flow on slugcatcher performance has also been assessed, both by direct measurement, and by use of a dynamic simulator. The simulator is used to test new control schemes prior to implementation. At low flowing velocities one line has been seen to undergo large pressure swings and to exhibit slug production due to liquid accumulation and sweepout. This effect is described, and re-produced using a transient simulator.

  16. Forcing scheme in pseudopotential lattice Boltzmann model for multiphase flows

    E-Print Network [OSTI]

    Q. Li; K. H. Luo; X. J. Li

    2012-04-18T23:59:59.000Z

    The pseudo-potential lattice Boltzmann (LB) model is a widely used multiphase model in the LB community. In this model, an interaction force, which is usually implemented via a forcing scheme, is employed to mimic the molecular interactions that cause phase segregation. The forcing scheme is therefore expected to play an important role in the pseudo-potential LB model. In this paper, we aim to address some key issues about forcing schemes in the pseudo-potential LB model. Firstly, theoretical and numerical analyses will be made for Shan-Chen's forcing scheme and the exact-difference-method (EDM) forcing scheme. The nature of these two schemes and their recovered macroscopic equations will be shown. Secondly, through a theoretical analysis, we will reveal the physics behind the phenomenon that different forcing schemes exhibit different performances in the pseudo-potential LB model. Moreover, based on the analysis, we will present an improved forcing scheme and numerically demonstrate that the improved scheme can be treated as an alternative approach for achieving thermodynamic consistency in the pseudo-potential LB model.

  17. Reactive Air Aluminization

    SciTech Connect (OSTI)

    Choi, Jung-Pyung; Chou, Y. S.; Stevenson, Jeffry W.

    2011-10-28T23:59:59.000Z

    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.

  18. 1154 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 49, NO. 5, OCTOBER 2002 A High-Torque Low-Speed Multiphase Brushless

    E-Print Network [OSTI]

    Simões, Marcelo Godoy

    -Speed Multiphase Brushless Machine--A Perspective Application for Electric Vehicles Marcelo Godoy Simões, Senior, analysis, simulation, and modeling of a high-torque low-speed multiphase permanent- magnet brushless-driven wheel motor drive system comprising a multiphase multipole topology controller. It presents the high

  19. Whitham's Method and Dubrovin-Novikov Bracket in Single-Phase and Multiphase Cases

    E-Print Network [OSTI]

    Andrei Ya. Maltsev

    2012-12-24T23:59:59.000Z

    In this paper we examine in detail the procedure of averaging of the local field-theoretic Poisson brackets proposed by B.A. Dubrovin and S.P. Novikov for the method of Whitham. The main attention is paid to the questions of justification and the conditions of applicability of the Dubrovin-Novikov procedure. Separate consideration is given to special features of single-phase and multiphase cases. In particular, one of the main results is the insensitivity of the procedure of bracket averaging to the appearance of "resonances" which can arise in the multi-phase situation.

  20. Some Specific CASL Requirements for Advanced Multiphase Flow Simulation of Light Water Reactors

    SciTech Connect (OSTI)

    R. A. Berry

    2010-11-01T23:59:59.000Z

    Because of the diversity of physical phenomena occuring in boiling, flashing, and bubble collapse, and of the length and time scales of LWR systems, it is imperative that the models have the following features: • Both vapor and liquid phases (and noncondensible phases, if present) must be treated as compressible. • Models must be mathematically and numerically well-posed. • The models methodology must be multi-scale. A fundamental derivation of the multiphase governing equation system, that should be used as a basis for advanced multiphase modeling in LWR coolant systems, is given in the Appendix using the ensemble averaging method. The remainder of this work focuses specifically on the compressible, well-posed, and multi-scale requirements of advanced simulation methods for these LWR coolant systems, because without these are the most fundamental aspects, without which widespread advancement cannot be claimed. Because of the expense of developing multiple special-purpose codes and the inherent inability to couple information from the multiple, separate length- and time-scales, efforts within CASL should be focused toward development of a multi-scale approaches to solve those multiphase flow problems relevant to LWR design and safety analysis. Efforts should be aimed at developing well-designed unified physical/mathematical and high-resolution numerical models for compressible, all-speed multiphase flows spanning: (1) Well-posed general mixture level (true multiphase) models for fast transient situations and safety analysis, (2) DNS (Direct Numerical Simulation)-like models to resolve interface level phenmena like flashing and boiling flows, and critical heat flux determination (necessarily including conjugate heat transfer), and (3) Multi-scale methods to resolve both (1) and (2) automatically, depending upon specified mesh resolution, and to couple different flow models (single-phase, multiphase with several velocities and pressures, multiphase with single velocity and pressure, etc.) A unified, multi-scale approach is advocated to extend the necessary foundations and build the capability to simultaneously solve the fluid dynamic interface problems (interface resolution) as well as multiphase mixtures (homogenization).

  1. Using a multiphase flow code to model the coupled effects of repository consolidation and multiphase brine and gas flow at the Waste Isolation Pilot Plant

    SciTech Connect (OSTI)

    Freeze, G.A. [INTERA Inc., Albuquerque, NM (United States); Larson, K.W.; Davies, P.B.; Webb, S.W. [Sandia National Labs., Albuquerque, NM (United States)

    1995-10-01T23:59:59.000Z

    Long-term repository assessment must consider the processes of (1) gas generation, (2) room closure and expansions due to salt creep, and (3) multiphase (brine and gas) fluid flow, as well as the complex coupling between these three processes. The mechanical creep closure code SANCHO was used to simulate the closure of a single, perfectly sealed disposal room filled with water and backfill. SANCHO uses constitutive models to describe salt creep, waste consolidation, and backfill consolidation, Five different gas-generation rate histories were simulated, differentiated by a rate multiplier, f, which ranged from 0.0 (no gas generation) to 1.0 (expected gas generation under brine-dominated conditions). The results of the SANCHO f-series simulations provide a relationship between gas generation, room closure, and room pressure for a perfectly sealed room. Several methods for coupling this relationship with multiphase fluid flow into and out of a room were examined. Two of the methods are described.

  2. Photovoltaic effect in multiphase Bi-Mn-O thin J. P. Chakrabartty,1

    E-Print Network [OSTI]

    Photovoltaic effect in multiphase Bi-Mn-O thin films J. P. Chakrabartty,1 R. Nechache,2,4 C and therefore the photovoltaic conversion efficiency. Specifically, a higher Bi/Mn ratio (towards unity separation. ©2013 Optical Society of America OCIS codes: (040.5350) Photovoltaic; (160.2260) Ferroelectrics

  3. The Effect of Slip Velocity on Saturation for Multiphase Condensing Mixtures in a PEM Fuel Cell

    E-Print Network [OSTI]

    Stockie, John

    The Effect of Slip Velocity on Saturation for Multiphase Condensing Mixtures in a PEM Fuel Cell in computed results reported in the fuel cell literature, but which has not yet received a satisfactory to treat the slip velocity between phases. Keywords: Condensation ­ Two Phase Flow ­ PEM Fuel Cell ­ Slip

  4. A SHARP INTERFACE REDUCTION FOR MULTIPHASE TRANSPORT IN A POROUS FUEL CELL ELECTRODE

    E-Print Network [OSTI]

    Stockie, John

    A SHARP INTERFACE REDUCTION FOR MULTIPHASE TRANSPORT IN A POROUS FUEL CELL ELECTRODE KEITH exchange membrane fuel cell is a highly porous material which acts to distribute reactant gases uniformly perturbation, fuel cell electrodes, free surface. AMS subject classifications. 35B40, 35K55, 76R99, 76S05 1

  5. A multiphase model for the early stages of the hydration of retarded oilwell cement

    E-Print Network [OSTI]

    Billingham, John

    A multiphase model for the early stages of the hydration of retarded oilwell cement J. Billingham, Birmingham B15 2TT, UK A.M. Harrisson The Rugby Group, RMC House Rugby CV21 2DT, UK Abstract. Cement is used in the oil industry to line oil wells. The major com- ponents of oilwell cement are tricalcium silicate (C3S

  6. GLOBAL OPTIMIZATION OF MULTIPHASE FLOW NETWORKS IN OIL AND GAS PRODUCTION SYSTEMS

    E-Print Network [OSTI]

    Johansen, Tor Arne

    1 GLOBAL OPTIMIZATION OF MULTIPHASE FLOW NETWORKS IN OIL AND GAS PRODUCTION SYSTEMS MSc. Hans in an oil production system is developed. Each well may be manipulated by injecting lift gas and adjusting in the maximum oil flow rate, water flow rate, liquid flow rate, and gas flow rate. The wells may also

  7. Multiphase flow and Encapsulation simulations using the moment of fluid method 1

    E-Print Network [OSTI]

    Sussman, Mark

    in order to demonstrate its capabilities. Examples are given in 2D, 3D axisymmetric (R-Z), and 3D (X Corporation, for the U. S. Department of Energy's National Nuclear Security Administration under contract DE. Introduction Multiphase flow plays an important role in many technical applications including ink-jet printing

  8. Design and Construction of a High Pressure System for Evaluating Multiphase Twin-Screw Pumps

    E-Print Network [OSTI]

    Hatch, Theodore Isaac

    2013-08-26T23:59:59.000Z

    drive ................................................................................ 42 Figure 27: Compressor removal from HVAC unit ........................................................... 48 Figure 28: Installation of heat exchanger support... INTRODUCTION 1.1 Background Twin-screw pumps are used in the oil industry to pump multiphase flows in a single pipeline where a separator, compressor, and two pipelines would otherwise be required. The ability to use existing single pipelines to pump...

  9. Multiphase fluid flow and time lapse UNLP, 11 Octubre de 2012

    E-Print Network [OSTI]

    Santos, Juan

    and time lapse seismics ­ p. #12;Introduction. III The analysis of CO2 underground storage safety and time lapse seismics ­ p. #12;Introduction. I Storage of CO2 in geological formations is a procedure project: Sleipner gas field (North Sea). Multiphase fluid flow and time lapse seismics ­ p. #12

  10. Fluctuation-induced dynamics of multiphase liquid jets with ultra-low interfacial tension

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Fluctuation-induced dynamics of multiphase liquid jets with ultra-low interfacial tension Alban with an ultra-low interfacial tension presents new opportunities to the control of flow morphologies perturbation; this demonstrates the importance of the inertial effects in flow control at ultra-low interfacial

  11. Dissolution of carbon dioxide bubbles and microfluidic multiphase flows Ruopeng Sun and Thomas Cubaud*

    E-Print Network [OSTI]

    Cubaud, Thomas

    Dissolution of carbon dioxide bubbles and microfluidic multiphase flows Ruopeng Sun and Thomas the dissolution of carbon dioxide bubbles into common liquids (water, ethanol, and methanol) using microfluidic devices. Elongated bubbles are individually produced using a hydrodynamic focusing section into a compact

  12. Stretch-flangeability of strong multiphase S. Chatterjee and H. K. D. H. Bhadeshia*

    E-Print Network [OSTI]

    Cambridge, University of

    steel, Dual phase steel, Strength Introduction Several methods have been designed to characteriseStretch-flangeability of strong multiphase steels S. Chatterjee and H. K. D. H. Bhadeshia* Stretch test data to indicate flangeabilty. It is found that the ultimate tensile strength of steel

  13. Formation of Droplets and Mixing in Multiphase Microfluidics at Low Values of the Reynolds and the

    E-Print Network [OSTI]

    Ismagilov, Rustem F.

    Formation of Droplets and Mixing in Multiphase Microfluidics at Low Values of the Reynolds to mixing. Droplet- based microfluidics offers a simple method of achieving rapid mixing and transport of using flow of immiscible fluids in microfluidic channels to form plugs containing multiple aqueous

  14. CFD Simulation and Experimental Testing of Multiphase Flow Inside the MVP Electrical Submersible Pump

    E-Print Network [OSTI]

    Rasmy Marsis, Emanuel 1983-

    2012-08-16T23:59:59.000Z

    The MVP is a special type of Electrical Submersible Pumps (ESPs) manufactured by Baker Hughes, model no. G470, and is capable of handling multiphase flow up to 70% Gas Volume Fraction (GVF). Flows at high GVF cause conventional ESPs to surge...

  15. d+Au Collisions from A MultiPhase Transport Model

    E-Print Network [OSTI]

    Lin, Zi-wei

    d+Au Collisions from A MultiPhase Transport Model Structure of AMPT Model Results for d's Parton Cascade) Partons freeze out Lund fragmentation to hadrons using HIJING ART (A Relativistic Transport model for hadrons) A+B Final output Zhang et al, PRC61; ZWL et al, PRC64, NPA698 Wang

  16. PARALLEL SOLUTION-ADAPTIVE SCHEME FOR MULTI-PHASE CORE FLOWS IN ROCKET MOTORS

    E-Print Network [OSTI]

    Groth, Clinton P. T.

    PARALLEL SOLUTION-ADAPTIVE SCHEME FOR MULTI-PHASE CORE FLOWS IN ROCKET MOTORS J. S. Sachdev , C. P motors (SRM). An Eulerian formulation is used for both the gas and particle phases, which leads THE internal flow dynamics of a solid propellant rocket motor (SRM) is very complex. The com- bustion

  17. A wave propagation method for compressible multiphase flow on mapped grids

    E-Print Network [OSTI]

    Shyue, Keh-Ming

    A wave propagation method for compressible multiphase flow on mapped grids K.-M. Shyue Department with a stiffened gas equation of state on body-fitted mapped grids in general two- and three-dimensional geometries, Body-fitted mapped grids, Wave propagation method, Stiffened gas equation of state 2000 MSC: 65M06, 65M

  18. Unsteady, high Reynolds number validation cases for a multi-phase CFD analysis tool have been

    E-Print Network [OSTI]

    Kunz, Robert Francis

    and constituent volume fraction transport/generation for liquid, condensable vapor and non-condensable gas fields1 Abstract Unsteady, high Reynolds number validation cases for a multi-phase CFD analysis tool have of the effect of cavitation number, Reynolds number and turbulence model has been made. Analysis of the modeled

  19. 1 Copyright 1999 by ASME MULTI-PHASE CFD ANALYSIS OF NATURAL AND VENTILATED CAVITATION

    E-Print Network [OSTI]

    Kunz, Robert Francis

    volume fraction transport/generation for liquid, condensable vapor and non-con- densable gas fields between condensable vapor and non-condensable gas, a requirement of our current applica- tion. By solving1 Copyright © 1999 by ASME MULTI-PHASE CFD ANALYSIS OF NATURAL AND VENTILATED CAVITATION ABOUT

  20. Multiphase Equilibrium of Fluids Confined in Fisher-Tropsch Catalytic Systems 

    E-Print Network [OSTI]

    Warrag, Samah

    2014-04-23T23:59:59.000Z

    Equation of state model extended to confined fluid (PR-C) has been utilized in multiphase equilibrium algorithm using FORTRAN. The simulation results provide the composition and the condition of each bulk phase and pore phase for a given initial mixture...

  1. Characterization of non-Darcy multiphase flow in petroleum bearing formations. Annual status report, May 14, 1991--May 13, 1992

    SciTech Connect (OSTI)

    Evans, R.D.; Civan, F.

    1992-12-31T23:59:59.000Z

    The objectives of this research are: Develop a proper theoretical model for characterizing non-Darcy multi-phase flow in petroleum bearing formations. Develop an experimental technique for measuring non-Darcy flow coefficients under multiphase flow at insitu reservoir conditions. Develop dimensional consistent correlations to express the non-Darcy flow coefficient as a function of rock and fluid properties for consolidated and unconsolidated porous media. The research accomplished during the period May 1991--May 1992 focused upon theoretical and experimental studies of multiphase non-Darcy flow in porous media.

  2. Surface tension of multi-phase flow with multiple junctions governed by the variational principle

    E-Print Network [OSTI]

    Shigeki Matsutani; Kota Nakano; Katsuhiko Shinjo

    2011-08-02T23:59:59.000Z

    We explore a computational model of an incompressible fluid with a multi-phase field in three-dimensional Euclidean space. By investigating an incompressible fluid with a two-phase field geometrically, we reformulate the expression of the surface tension for the two-phase field found by Lafaurie, Nardone, Scardovelli, Zaleski and Zanetti (J. Comp. Phys. \\vol{113} \\yr{1994} \\pages{134-147}) as a variational problem related to an infinite dimensional Lie group, the volume-preserving diffeomorphism. The variational principle to the action integral with the surface energy reproduces their Euler equation of the two-phase field with the surface tension. Since the surface energy of multiple interfaces even with singularities is not difficult to be evaluated in general and the variational formulation works for every action integral, the new formulation enables us to extend their expression to that of a multi-phase ($N$-phase, $N\\ge2$) flow and to obtain a novel Euler equation with the surface tension of the multi-phase field. The obtained Euler equation governs the equation of motion of the multi-phase field with different surface tension coefficients without any difficulties for the singularities at multiple junctions. In other words, we unify the theory of multi-phase fields which express low dimensional interface geometry and the theory of the incompressible fluid dynamics on the infinite dimensional geometry as a variational problem. We apply the equation to the contact angle problems at triple junctions. We computed the fluid dynamics for a two-phase field with a wall numerically and show the numerical computational results that for given surface tension coefficients, the contact angles are generated by the surface tension as results of balances of the kinematic energy and the surface energy.

  3. A Tariff for Reactive Power

    SciTech Connect (OSTI)

    Kueck, John D [ORNL; Kirby, Brendan J [ORNL; Li, Fangxing [ORNL; Tufon, Christopher [Pacific Gas and Electric Company; Isemonger, Alan [California Independent System Operator

    2008-07-01T23:59:59.000Z

    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.

  4. Application of reactive transport modelling to growth and transport of microorganisms in the capillary fringe

    E-Print Network [OSTI]

    Hron, Pavel; Bastian, Peter; Gallert, Claudia; Winter, Josef; Ippisch, Olaf

    2014-01-01T23:59:59.000Z

    A multicomponent multiphase reactive transport simulator has been developed to facilitate the investigation of a large variety of phenomena in porous media including component transport, diffusion, microbiological growth and decay, cell attachment and detachment and phase exchange. The coupled problem is solved using operator splitting. This approach allows a flexible adaptation of the solution strategy to the concrete problem. Moreover, the individual submodels were optimised to be able to describe behaviour of Escherichia coli (HB101 K12 pGLO) in the capillary fringe in the presence or absence of dissolved organic carbon and oxygen under steady-state and flow conditions. Steady-state and flow through experiments in a Hele-Shaw cell, filled with quartz sand, were conducted to study eutrophic bacterial growth and transport in both saturated and unsaturated porous media. As E. coli cells can form the green fluorescent protein (GFP), the cell densities, calculated by evaluation of measured fluorescence intensit...

  5. Electrocatalytic Reactivity for Oxygen Reduction of Palladium...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Reactivity for Oxygen Reduction of Palladium-Modified Carbon Nanotubes Synthesized in Supercritical Fluid. Electrocatalytic Reactivity for Oxygen Reduction of Palladium-Modified...

  6. Formation, characterization and reactivity of adsorbed oxygen...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Formation, characterization and reactivity of adsorbed oxygen on BaOPt(111). Formation, characterization and reactivity of adsorbed oxygen on BaOPt(111). Abstract: The formation...

  7. Methods, systems and apparatus for approximation of peak summed fundamental and third harmonic voltages in a multi-phase machine

    SciTech Connect (OSTI)

    Ransom, Ray M. (Big Bear City, CA); Gallegos-Lopez, Gabriel (Torrance, CA); Kinoshita, Michael H. (Redondo Beach, CA)

    2012-07-31T23:59:59.000Z

    Methods, system and apparatus are provided for quickly approximating a peak summed magnitude (A) of a phase voltage (Vph) waveform in a multi-phase system that implements third harmonic injection.

  8. Numerical modeling of multiphase plumes: a comparative study between two-fluid and mixed-fluid integral models 

    E-Print Network [OSTI]

    Bhaumik, Tirtharaj

    2005-11-01T23:59:59.000Z

    Understanding the physics of multiphase plumes and their simulation through numerical modeling has been an important area of research in recent times in the area of environmental fluid mechanics. The two renowned numerical modeling types...

  9. Conservation of reactive electromagnetic energy in reactive time

    E-Print Network [OSTI]

    Kaiser, Gerald

    2015-01-01T23:59:59.000Z

    The complex Poynting theorem (CPT) is extended to a canonical time-scale domain $(t,s)$. Time-harmonic phasors are replaced by the positive-frequency parts of general fields, which extend analytically to complex time $t+is$, with $s>0$ interpreted as a time resolution scale. The real part of the extended CPT gives conservation in $t$ of a time-averaged field energy, and its imaginary part gives conservation in $s$ of a time-averaged reactive energy. In both cases, the averaging windows are determined by a Cauchy kernel of width $\\Delta t\\sim \\pm s$. This completes the time-harmonic CPT, whose imaginary part is generally supposed to be vaguely `related to' reactive energy without giving a conservation law, or even an expression, for the latter. The interpretation of $s$ as reactive time, tracking the leads and lags associated with stored capacitative and inductive energy, gives a simple explanation of the volt-ampere reactive (var) unit measuring reactive power: a var is simply one Joule per reactive second. T...

  10. Fuel Temperature Coefficient of Reactivity

    SciTech Connect (OSTI)

    Loewe, W.E.

    2001-07-31T23:59:59.000Z

    A method for measuring the fuel temperature coefficient of reactivity in a heterogeneous nuclear reactor is presented. The method, which is used during normal operation, requires that calibrated control rods be oscillated in a special way at a high reactor power level. The value of the fuel temperature coefficient of reactivity is found from the measured flux responses to these oscillations. Application of the method in a Savannah River reactor charged with natural uranium is discussed.

  11. Laboratory setup and results of experiments on two-dimensional multiphase flow in porous media

    SciTech Connect (OSTI)

    McBride, J.F. (ed.) (Pacific Northwest Lab., Richland, WA (USA)); Graham, D.N. (ed.); Schiegg, H.O. (SIMULTEC Ltd., Meilen/Zurich (Switzerland))

    1990-10-01T23:59:59.000Z

    In the event of an accidental release into earth's subsurface of an immiscible organic liquid, such as a petroleum hydrocarbon or chlorinated organic solvent, the spatial and temporal distribution of the organic liquid is of great interest when considering efforts to prevent groundwater contamination or restore contaminated groundwater. An accurate prediction of immiscible organic liquid migration requires the incorporation of relevant physical principles in models of multiphase flow in porous media; these physical principles must be determined from physical experiments. This report presents a series of such experiments performed during the 1970s at the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland. The experiments were designed to study the transient, two-dimensional displacement of three immiscible fluids in a porous medium. This experimental study appears to be the most detailed published to date. The data obtained from these experiments are suitable for the validation and test calibration of multiphase flow codes. 73 refs., 140 figs.

  12. Design and Construction of a High Pressure System for Evaluating Multiphase Twin-Screw Pumps 

    E-Print Network [OSTI]

    Hatch, Theodore Isaac

    2013-08-26T23:59:59.000Z

    INTRODUCTION 1.1 Background Twin-screw pumps are used in the oil industry to pump multiphase flows in a single pipeline where a separator, compressor, and two pipelines would otherwise be required. The ability to use existing single pipelines to pump...- screw pump and a single pipeline instead of a traditional separator, pump, compressor, and twin pipelines reduces the initial capital cost of the equipment as well as the operating costs. 4 2.2 Pump Performance Metrics Characteristic...

  13. Coherent Structures in Turbulent Flows: Experimental Studies on the Turbulence of Multiphase Plumes and Tidal Vortices

    E-Print Network [OSTI]

    Bryant, Duncan Burnette

    2011-08-08T23:59:59.000Z

    Akker 1999), and ocean CO2 sequestration (Adams and Wannamaker 2005; Adams and Wannamaker 2006). In particular, ocean CO2 sequestration has been noted by the Intergovernmental Panel on Climate Change in its 2005 special report on Carbon Dioxide... for direct carbon sequestration in the oceans have been considered as a means to mitigate the effects on global warming of burning fossil fuels. While the concept of CO2 sequestration is promising, the turbulent structures in multiphase plumes...

  14. A high precision TDC based on a multi-phase clock

    E-Print Network [OSTI]

    Zhong Qi; Xiangting Meng; Deyuan Li; Lei Yang; Zeen Yao; Dongcang Li

    2015-02-04T23:59:59.000Z

    The design of a high-precision time-to-digital converter (TDC) based on a multiphase clock implemented using a single field-programmable gate array is discussed in this paper. The TDC can increase the resolution of the measurement by using time interpolation. A phase-locked loop is used to generate four multiphase clocks whose frequencies are the same and whose phases are 0{\\deg}, 45{\\deg}, 90{\\deg}, and 135{\\deg}. In addition, the duty ratios of the four clocks are 50%. By utilizing four multiphase clocks to make up the interpolation clock, one clock period can be divided into eight uniform parts. The resolution of the TDC can be improved to 1/8 of a clock period. Furthermore, we have also designed a discriminator circuit for identifying the start and stop signals. On the basis of this circuit, the TDC can still measure the time interval of two signals when the start and stop signals are uncertain. The experimental results indicate that the time resolution of the TDC can achieve the theoretical value, and the linearity is very good. The architecture consumes fewer logic cells and is more stable.

  15. Reactive Ion Etch Users Guide

    E-Print Network [OSTI]

    Wager, John F.

    RIE Reactive Ion Etch Users Guide Eric Sundholm 2-22-2007 Standby Condition: be sure that the tool the chamber to remove any potential hazards before the chamber can be opened. 9. Pump Down Chamber Utilities Pump Chamber 10. Check pressure to start turbo pump Display Sensor Display a. Wait for pressure

  16. TOUGH2: A general-purpose numerical simulator for multiphase nonisothermal flows

    SciTech Connect (OSTI)

    Pruess, K. [Lawrence Berkeley Lab., CA (United States)

    1991-06-01T23:59:59.000Z

    Numerical simulators for multiphase fluid and heat flows in permeable media have been under development at Lawrence Berkeley Laboratory for more than 10 yr. Real geofluids contain noncondensible gases and dissolved solids in addition to water, and the desire to model such `compositional` systems led to the development of a flexible multicomponent, multiphase simulation architecture known as MULKOM. The design of MULKOM was based on the recognition that the mass-and energy-balance equations for multiphase fluid and heat flows in multicomponent systems have the same mathematical form, regardless of the number and nature of fluid components and phases present. Application of MULKOM to different fluid mixtures, such as water and air, or water, oil, and gas, is possible by means of appropriate `equation-of-state` (EOS) modules, which provide all thermophysical and transport parameters of the fluid mixture and the permeable medium as a function of a suitable set of primary thermodynamic variables. Investigations of thermal and hydrologic effects from emplacement of heat-generating nuclear wastes into partially water-saturated formations prompted the development and release of a specialized version of MULKOM for nonisothermal flow of water and air, named TOUGH. TOUGH is an acronym for `transport of unsaturated groundwater and heat` and is also an allusion to the tuff formations at Yucca Mountain, Nevada. The TOUGH2 code is intended to supersede TOUGH. It offers all the capabilities of TOUGH and includes a considerably more general subset of MULKOM modules with added capabilities. The paper briefly describes the simulation methodology and user features.

  17. Engine combustion control via fuel reactivity stratification

    DOE Patents [OSTI]

    Reitz, Rolf Deneys; Hanson, Reed M; Splitter, Derek A; Kokjohn, Sage L

    2013-12-31T23:59:59.000Z

    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).

  18. Particle Swarm Optimization Based Reactive Power Optimization

    E-Print Network [OSTI]

    Sujin, P R; Linda, M Mary

    2010-01-01T23:59:59.000Z

    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...

  19. Mitochondrial reactive oxygen species and cancer

    E-Print Network [OSTI]

    Chandel, Navdeep S

    Mitochondria produce reactive oxygen species (mROS) as a natural by-product of electron transport chain activity. While initial studies focused on the damaging effects of reactive oxygen species, a recent paradigm shift ...

  20. Triangular flow in heavy ion collisions in a multiphase transport model

    E-Print Network [OSTI]

    Jun Xu; Che Ming Ko

    2011-06-28T23:59:59.000Z

    We have obtained a new set of parameters in a multiphase transport (AMPT) model that are able to describe both the charged particle multiplicity density and elliptic flow measured in Au+Au collisions at center of mass energy $\\sqrt{s_{NN}}=200$ GeV at the Relativistic Heavy Ion Collider (RHIC), although they still give somewhat softer transverse momentum spectra. We then use the model to predict the triangular flow due to fluctuations in the initial collision geometry and study its effect relative to those from other harmonic components of anisotropic flows on the di-hadron azimuthal correlations in both central and mid-central collisions.

  1. Sampling device for withdrawing a representative sample from single and multi-phase flows

    DOE Patents [OSTI]

    Apley, Walter J. (Pasco, WA); Cliff, William C. (Richland, WA); Creer, James M. (Richland, WA)

    1984-01-01T23:59:59.000Z

    A fluid stream sampling device has been developed for the purpose of obtaining a representative sample from a single or multi-phase fluid flow. This objective is carried out by means of a probe which may be inserted into the fluid stream. Individual samples are withdrawn from the fluid flow by sampling ports with particular spacings, and the sampling parts are coupled to various analytical systems for characterization of the physical, thermal, and chemical properties of the fluid flow as a whole and also individually.

  2. Chemically and compositionally modified solid solution disordered multiphase nickel hydroxide positive electrode for alkaline rechargeable electrochemical cells

    DOE Patents [OSTI]

    Ovshinsky, Stanford R. (Bloomfield Hills, MI); Corrigan, Dennis (Troy, MI); Venkatesan, Srini (Southfield, MI); Young, Rosa (Troy, MI); Fierro, Christian (Troy, MI); Fetcenko, Michael A. (Rochester Hills, MI)

    1994-01-01T23:59:59.000Z

    A high capacity, long cycle life positive electrode for use in an alkaline rechargeable electrochemical cell comprising: a solid solution nickel hydroxide material having a multiphase structure that comprises at least one polycrystalline .gamma.-phase including a polycrystalline .gamma.-phase unit cell comprising spacedly disposed plates with at least one chemical modifier incorporated around the plates, the plates having a range of stable intersheet distances corresponding to a 2.sup.+ oxidation state and a 3.5.sup.+, or greater, oxidation state; and at least one compositional modifier incorporated into the solid solution nickel hydroxide material to promote the multiphase structure.

  3. Reactive composite compositions and mat barriers

    DOE Patents [OSTI]

    Langton, Christine A. (Aiken, SC); Narasimhan, Rajendran (Evans, GA); Karraker, David G. (Aiken, SC)

    2001-01-01T23:59:59.000Z

    A hazardous material storage area has a reactive multi-layer composite mat which lines an opening into which a reactive backfill and hazardous material are placed. A water-inhibiting cap may cover the hazardous material storage area. The reactive multi-layer composite mat has a backing onto which is placed an active layer which will neutralize or stabilize hazardous waste and a fronting layer so that the active layer is between the fronting and backing layers. The reactive backfill has a reactive agent which can stabilize or neutralize hazardous material and inhibit the movement of the hazardous material through the hazardous material storage area.

  4. A Multiphase, Modular, Bidirectional, Triple-Voltage DC-DC Converter Power Systems

    SciTech Connect (OSTI)

    Su, Gui-Jia [ORNL; Tang, Lixin [ORNL

    2008-01-01T23:59:59.000Z

    Electrical power systems in future hybrid and fuel cell vehicles may employ three voltage [14 V, 42 V, and high voltage (HV)] nets. These will be necessary to accommodate existing 14-V loads as well as efficiently handle new heavy loads at the 42-V net and a traction drive on the HV bus. A low-cost DC-DC converter was proposed for connecting the three voltage nets. It minimizes the number of switches and their associated gate driver components by using two half-bridges and a high-frequency transformer. Another salient feature is that the half bridge on the 42-V bus is also utilized to provide the 14-V bus by operating at duty ratios around an atypical value of 1/3. Moreover, it makes use of the parasitic capacitance of the switches and the transformer leakage inductance for soft switching. The use of half bridges makes the topology well suited for interleaved multiphase modular configurations as a means to increase the power level because the capacitor legs can be shared. This paper presents simulation and experimental results on an interleaved two-phase arrangement rated at 4.5 kW. Also discussed are the benefits of operating with an atypical duty ratio on the transformer and a preferred multiphase configuration to minimize capacitor ripple currents.

  5. Mechanism-based Representative Volume Elements (RVEs) for Predicting Property Degradations in Multiphase Materials

    SciTech Connect (OSTI)

    Xu, Wei; Sun, Xin; Li, Dongsheng; Ryu, Seun; Khaleel, Mohammad A.

    2013-02-01T23:59:59.000Z

    Quantitative understanding of the evolving thermal-mechanical properties of a multi-phase material hinges upon the availability of quantitative statistically representative microstructure descriptions. Questions then arise as to whether a two-dimensional (2D) or a three-dimensional (3D) representative volume element (RVE) should be considered as the statistically representative microstructure. Although 3D models are more representative than 2D models in general, they are usually computationally expensive and difficult to be reconstructed. In this paper, we evaluate the accuracy of a 2D RVE in predicting the property degradations induced by different degradation mechanisms with the multiphase solid oxide fuel cell (SOFC) anode material as an example. Both 2D and 3D microstructure RVEs of the anodes are adopted to quantify the effects of two different degradation mechanisms: humidity-induced electrochemical degradation and phosphorus poisoning induced structural degradation. The predictions of the 2D model are then compared with the available experimental measurements and the results from the 3D model. It is found that the 2D model, limited by its inability of reproducing the realistic electrical percolation, is unable to accurately predict the degradation of thermo-electrical properties. On the other hand, for the phosphorus poisoning induced structural degradation, both 2D and 3D microstructures yield similar results, indicating that the 2D model is capable of providing computationally efficient yet accurate results for studying the structural degradation within the anodes.

  6. A Physically Based Approach for Modeling Multiphase Fracture-Matrix Interaction in Fractured Porous Media

    SciTech Connect (OSTI)

    Wu, Yu-Shu; Pan, Lehua; Pruess, Karsten

    2004-03-15T23:59:59.000Z

    Modeling fracture-matrix interaction within a complex multiple phase flow system is a key issue for fractured reservoir simulation. Commonly used mathematical models for dealing with such interactions employ a dual- or multiple-continuum concept, in which fractures and matrix are represented as overlapping, different, but interconnected continua, described by parallel sets of conservation equations. The conventional single-point upstream weighting scheme, in which the fracture relative permeability is used to represent the counterpart at the fracture-matrix interface, is the most common scheme by which to estimate flow mobility for fracture-matrix flow terms. However, such a scheme has a serious flaw, which may lead to unphysical solutions or significant numerical errors. To overcome the limitation of the conventional upstream weighting scheme, this paper presents a physically based modeling approach for estimating physically correct relative permeability in calculating multiphase flow between fractures and the matrix, using continuity of capillary pressure at the fracture-matrix interface. The proposed approach has been implemented into two multiphase reservoir simulators and verified using analytical solutions and laboratory experimental data. The new method is demonstrated to be accurate, numerically efficient, and easy to implement in dual- or multiple-continuum models.

  7. Does the schock wave in a highly ionized non-isothermal plasma really exist ?

    E-Print Network [OSTI]

    Rukhadze, A A; Samkharadze, T

    2015-01-01T23:59:59.000Z

    Here we study the structure of a highly ionizing shock wave in a gas of high atmospheric pressure. We take into account the gas ionization when the gas temperature reaches few orders of an ionization potential. It is shown that after gasdynamic temperature-raising shock and formation of a highly-ionized nonisothermal plasma $T_e>>T_i$ only the solitary ion-sound wave (soliton) can propagate in this plasma. In such a wave the charge separation occurs: electrons and ions form the double electric layer with the electric field. The shock wave form, its amplitude and front width are obtained.

  8. NON-ISOTHERMAL INJECTION MOULDING WITH RESIN CURE AND PREFORM DEFORMABILITY

    E-Print Network [OSTI]

    Preziosi, Luigi

    Transfer Molding), SRIM (Structural Resin Injection Molding), SCRIMP (Seeman Com- posite Resin Infusion

  9. Growing and moving low-mass planets in non-isothermal disks

    E-Print Network [OSTI]

    S. -J. Paardekooper; G. Mellema

    2007-11-22T23:59:59.000Z

    We study the interaction of a low-mass planet with a protoplanetary disk with a realistic treatment of the energy balance by doing radiation-hydrodynamical simulations. We look at accretion and migration rates and compare them to isothermal studies. We used a three-dimensional version of the hydrodynamical method RODEO, together with radiative transport in the flux-limited diffusion approach. The accretion rate, as well as the torque on the planet, depend critically on the ability of the disk to cool efficiently. For densities appropriate to 5 AU in the solar nebula, the accretion rate drops by more than an order of magnitude compared to isothermal models, while at the same time the torque on the planet is positive, indicating outward migration. It is necessary to lower the density by a factor of 2 to recover inward migration and more than 2 orders of magnitude to recover the usual Type I migration. The torque appears to be proportional to the radial entropy gradient in the unperturbed disk. These findings are critical for the survival of protoplanets, and they should ultimately find their way into population synthesis models.

  10. Growing and moving low-mass planets in non-isothermal disks

    E-Print Network [OSTI]

    Paardekooper, S -J

    2007-01-01T23:59:59.000Z

    We study the interaction of a low-mass planet with a protoplanetary disk with a realistic treatment of the energy balance by doing radiation-hydrodynamical simulations. We look at accretion and migration rates and compare them to isothermal studies. We used a three-dimensional version of the hydrodynamical method RODEO, together with radiative transport in the flux-limited diffusion approach. The accretion rate, as well as the torque on the planet, depend critically on the ability of the disk to cool efficiently. For densities appropriate to 5 AU in the solar nebula, the accretion rate drops by more than an order of magnitude compared to isothermal models, while at the same time the torque on the planet is positive, indicating outward migration. It is necessary to lower the density by a factor of 2 to recover inward migration and more than 2 orders of magnitude to recover the usual Type I migration. The torque appears to be proportional to the radial entropy gradient in the unperturbed disk. These findings ar...

  11. Modeling non-isothermal intermetallic layer growth in the 63Sn-37Pb/Cu system

    SciTech Connect (OSTI)

    Vianco, P.T.; Hopkins, P.L.; Erickson, K.L.; Frear, D.R.; Davidson, R.

    1996-12-31T23:59:59.000Z

    A model describing diffusion-controlled growth of multiple intermetallic layers and the displacement of the interfaces between layers was developed and implemented in a 1-D computer code based on method-of-lines. The code was applied to analysis of intermetallic layer growth in isothermal solder aging experiments performed with 100 Sn/Cu and 63Sn-37Pb/Cu solder-substrate systems. Analyses indicated that intermetallic layer growth was consistent with a bulk diffusion mechanism involving Cu and/or Sn. In this work, nonisothermal solder-aging experiments were done with the 63Sn- 37Pb/Cu system using two temperature histories (4 cycles/day between 223-443 K, and 72 cycles/day between 223-443 K). Isothermal experiments were also done at 443 K. Thickness of Cu{sub 3}Sn and Cu{sub 6}Sn{sub 5} intermetallic layers were determined vs time for each temperature history. An updated version of the model and code were used to predict the intermetallic layer growth. Arrhenius expressions for diffusion coefficients in both Cu3Sn and Cu6Sn5 layers were determined. Agreement between prediction and experiment was generally good. In some cases, predicted layer growth was less than experiment, but within error. This paper describes the nonisothermal experiments and a comparison of predicted and observed layer growth vs time.

  12. A non-isothermal model of a nickelmetal hydride cell , M. Mohammedb

    E-Print Network [OSTI]

    ) to avoid oxygen gas generation during over discharge and has extra capacity to avoid hydrogen gas generation during over- charge. Since the metal hydride material gradually loses capacity through usage due. The side reaction at the positive electrode is oxygen evolu- tion and at the negative electrode oxygen

  13. RESIK Solar X-ray flare element abundances on a non-isothermal assumption

    E-Print Network [OSTI]

    Sylwester, B; Sylwester, J; Kepa, A

    2015-01-01T23:59:59.000Z

    Solar X-ray spectra from the RESIK crystal spectrometer on the {\\em CORONAS-F} spacecraft (spectral range $3.3-6.1$~\\AA) are analyzed for thirty-three flares using a method to derive abundances of Si, S, Ar, and K, emission lines of which feature prominently in the spectra. For each spectrum, the method first optimizes element abundances then derives the differential emission measure as a function of temperature based on a procedure given by Sylwester et al. and Withbroe. This contrasts with our previous analyses of RESIK spectra in which an isothermal assumption was used. The revised abundances (on a logarithmic scale with $A({\\rm H}) = 12$) averaged for all the flares in the analysis are $A({\\rm Si}) = 7.53 \\pm 0.08$ (previously $7.89 \\pm 0.13$), $A({\\rm S}) = 6.91 \\pm 0.07$ ($7.16 \\pm 0.17$), $A({\\rm Ar}) = 6.47 \\pm 0.08$ ($6.45 \\pm 0.07$), and $A({\\rm K}) = 5.73 \\pm 0.19$ ($5.86 \\pm 0.20$), with little evidence for time variations of abundances within the evolution of each flare. Our previous estimates of...

  14. Microstructure and strength modelling of AlCuMg alloys during non-isothermal

    E-Print Network [OSTI]

    and transmission electron microscopy data for a fusion welded 2024-T351 aluminium alloy. The model predicts solid tested normal to the weld is mainly due to the co-clusters. Keywords: Aluminium alloys, Ageing, Modelling for welding of aluminium alloys in a range of aerospace and automotive applications.11­13 The VPPAW process

  15. Gelification and mass transport in a static non-isothermal waxy solution

    E-Print Network [OSTI]

    Primicerio, Mario

    and sedimentation are usually neglected in the deposition process (see [1]). In this paper we investigate and model Tgel (dispersion difference between the present study and the models investigated in previous papers (see [12], [13], [14

  16. Multiphase Science and Technology, Vol. 13, No. 3, pp. 207-232, 2001 CRITICAL HEAT FLUX IN SUBCOOLED FLOW

    E-Print Network [OSTI]

    Kandlikar, Satish

    Multiphase Science and Technology, Vol. 13, No. 3, pp. 207-232, 2001 CRITICAL HEAT FLUX. Kandlikar Mechanical Engineering Department, Rochester Institute of Technology, Rochester, NY 14623, USA Abstract. Critical Heat Flux, or CHF, is an important condition that defines the upper limit of safe

  17. Virtual Measurement in Pipes, Part 1: Flowing Bottom Hole Pressure Under Multi-Phase Flow and Inclined Wellbore Conditions

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    SPE 30975 Virtual Measurement in Pipes, Part 1: Flowing Bottom Hole Pressure Under Multi-Phase Flow, 163245 SPEUT. Abstract Pressure drop prediction in pipes is an old petroleum engineering problem. There is a long history of attempts to develop empirical correlations to predict the pressure drop in pipes. Some

  18. Abstract --A systematic framework for reliability assessment and fault-tolerant design of multiphase dc-dc

    E-Print Network [OSTI]

    Liberzon, Daniel

    reliability. Index Terms--Markov reliability modeling, maximum power point tracking, photovoltaics, switch1 Abstract -- A systematic framework for reliability assessment and fault-tolerant design of multiphase dc-dc converters deployed in photovoltaic applications is presented. System-level steady

  19. 5th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion Xian, China, 36 July 2005

    E-Print Network [OSTI]

    Aguilar, Guillermo

    5th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion Xian, such as hemangiomas and port wine stain (PWS) birthmarks, are congenital and pro- gressive vascular malformations of the dermis. To remove them, laser energy is irradiated at appropriate wavelengths inducing permanent thermal

  20. A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat Flow Simulations

    E-Print Network [OSTI]

    Elmroth, Erik

    A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat groundwater flow related problems such as nuclear waste isolation, environmental remediation, and geothermal with ¢¡¤£¦¥§ ¨¡© blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid partitioning

  1. A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat Flow Simulations

    E-Print Network [OSTI]

    Elmroth, Erik

    A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat groundwater flow related problems such as nuclear waste isolation, environmental remediation, and geothermal 6 blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid

  2. The application of multidimensional wavelets to unveiling multi-phase diagrams and in situ physical properties of rocks

    E-Print Network [OSTI]

    Vasilyev, Oleg V.

    properties of rocks Oleg V. Vasilyeva,*, Taras V. Geryab,c , David A. Yuend a Department of Mechanical of complicated realistic multi-phase diagrams and related in situ physical properties of rocks by using calculation of equilibrium phase assemblages and prediction of in situ physical properties of rocks [15

  3. AOI 1— COMPUTATIONAL ENERGY SCIENCES:MULTIPHASE FLOW RESEARCH High-fidelity multi-phase radiation module for modern coal combustion systems

    SciTech Connect (OSTI)

    Modest, Michael

    2013-11-15T23:59:59.000Z

    The effects of radiation in particle-laden flows were the object of the present research. The presence of particles increases optical thickness substantially, making the use of the “optically thin” approximation in most cases a very poor assumption. However, since radiation fluxes peak at intermediate optical thicknesses, overall radiative effects may not necessarily be stronger than in gas combustion. Also, the spectral behavior of particle radiation properties is much more benign, making spectral models simpler (and making the assumption of a gray radiator halfway acceptable, at least for fluidized beds when gas radiation is not large). On the other hand, particles scatter radiation, making the radiative transfer equation (RTE) much more di#14;fficult to solve. The research carried out in this project encompassed three general areas: (i) assessment of relevant radiation properties of particle clouds encountered in fluidized bed and pulverized coal combustors, (ii) development of proper spectral models for gas–particulate mixtures for various types of two-phase combustion flows, and (iii) development of a Radiative Transfer Equation (RTE) solution module for such applications. The resulting models were validated against artificial cases since open literature experimental data were not available. The final models are in modular form tailored toward maximum portability, and were incorporated into two research codes: (i) the open-source CFD code OpenFOAM, which we have extensively used in our previous work, and (ii) the open-source multi-phase flow code MFIX, which is maintained by NETL.

  4. Layered reactive particles with controlled geometries, energies, and reactivities, and methods for making the same

    DOE Patents [OSTI]

    Fritz, Gregory M; Knepper, Robert Allen; Weihs, Timothy P; Gash, Alexander E; Sze, John S

    2013-04-30T23:59:59.000Z

    An energetic composite having a plurality of reactive particles each having a reactive multilayer construction formed by successively depositing reactive layers on a rod-shaped substrate having a longitudinal axis, dividing the reactive-layer-deposited rod-shaped substrate into a plurality of substantially uniform longitudinal segments, and removing the rod-shaped substrate from the longitudinal segments, so that the reactive particles have a controlled, substantially uniform, cylindrically curved or otherwise rod-contoured geometry which facilitates handling and improves its packing fraction, while the reactant multilayer construction controls the stability, reactivity and energy density of the energetic composite.

  5. A thermodynamical formulation for chemically active multi-phase turbulent flows

    SciTech Connect (OSTI)

    Ahmadi, G.; Cao, J.

    1995-03-01T23:59:59.000Z

    A generalized thermodynamics for chemically active multiphase solid-fluid mixtures in turbulent state of motion is formulated. The global equations of balance for each phase are ensemble averaged and the local conservation laws for the mean motions are derived. The averaged and the local conservation laws for the mean motions are derived. The averaged form of the Clausius-Duhem inequality is used and the thermodynamics of the chemically active mixtures in turbulent motion is studied. Particular attention is given to the species concentration and chemical reaction effects, in addition to transport and interaction of the phasic fluctuation energies. Based on the averaged entropy inequality, constitutive equations for the stresses, energy, heat and mass fluxes of various species are developed. The explicit governing equations of motion are derived and discussed.

  6. Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Processes

    SciTech Connect (OSTI)

    Yortsos, Yanis C.

    2001-08-07T23:59:59.000Z

    This project is an investigation of various multi-phase and multiscale transport and reaction processes associated with heavy oil recovery. The thrust areas of the project include the following: Internal drives, vapor-liquid flows, combustion and reaction processes, fluid displacements and the effect of instabilities and heterogeneities and the flow of fluids with yield stress. These find respective applications in foamy oils, the evolution of dissolved gas, internal steam drives, the mechanics of concurrent and countercurrent vapor-liquid flows, associated with thermal methods and steam injection, such as SAGD, the in-situ combustion, the upscaling of displacements in heterogeneous media and the flow of foams, Bingham plastics and heavy oils in porous media and the development of wormholes during cold production.

  7. Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Processes

    SciTech Connect (OSTI)

    Yortsos, Y.C.

    2001-05-29T23:59:59.000Z

    This report is an investigation of various multi-phase and multiscale transport and reaction processes associated with heavy oil recovery. The thrust areas of the project include the following: Internal drives, vapor-liquid flows, combustion and reaction processes, fluid displacements and the effect of instabilities and heterogeneities and the flow of fluids with yield stress. These find respective applications in foamy oils, the evolution of dissolved gas, internal steam drives, the mechanics of concurrent and countercurrent vapor-liquid flows, associated with thermal methods and steam injection, such as SAGD, the in-situ combustion, the upscaling of displacements in heterogeneous media and the flow of foams, Bingham plastics and heavy oils in porous media and the development of wormholes during cold production.

  8. Integrated acoustic phase separator and multiphase fluid composition monitoring apparatus and method

    DOE Patents [OSTI]

    Sinha, Dipen N

    2014-02-04T23:59:59.000Z

    An apparatus and method for down hole gas separation from the multiphase fluid flowing in a wellbore or a pipe, for determining the quantities of the individual components of the liquid and the flow rate of the liquid, and for remixing the component parts of the fluid after which the gas volume may be measured, without affecting the flow stream, are described. Acoustic radiation force is employed to separate gas from the liquid, thereby permitting measurements to be separately made for these two components; the liquid (oil/water) composition is determined from ultrasonic resonances; and the gas volume is determined from capacitance measurements. Since the fluid flows around and through the component parts of the apparatus, there is little pressure difference, and no protection is required from high pressure differentials.

  9. Circulating fluidized bed hydrodynamics experiments for the multiphase fluid dynamics research consortium (MFDRC).

    SciTech Connect (OSTI)

    Oelfke, John Barry; Torczynski, John Robert; O'Hern, Timothy John; Tortora, Paul Richard; Bhusarapu, Satish (; ); Trujillo, Steven Mathew

    2006-08-01T23:59:59.000Z

    An experimental program was conducted to study the multiphase gas-solid flow in a pilot-scale circulating fluidized bed (CFB). This report describes the CFB experimental facility assembled for this program, the diagnostics developed and/or applied to make measurements in the riser section of the CFB, and the data acquired for several different flow conditions. Primary data acquired included pressures around the flow loop and solids loadings at selected locations in the riser. Tomographic techniques using gamma radiation and electrical capacitance were used to determine radial profiles of solids volume fraction in the riser, and axial profiles of the integrated solids volume fraction were produced. Computer Aided Radioactive Particle Tracking was used to measure solids velocities, fluxes, and residence time distributions. In addition, a series of computational fluid dynamics simulations was performed using the commercial code Arenaflow{trademark}.

  10. Ultrasonic tomography for in-process measurements of temperature in a multi-phase medium

    DOE Patents [OSTI]

    Beller, L.S.

    1993-01-26T23:59:59.000Z

    A method and apparatus are described for the in-process measurement of internal particulate temperature utilizing ultrasonic tomography techniques to determine the speed of sound through a specimen material. Ultrasonic pulses are transmitted through a material, which can be a multi-phase material, over known flight paths and the ultrasonic pulse transit times through all sectors of the specimen are measured to determine the speed of sound. The speed of sound being a function of temperature, it is possible to establish the correlation between speed of sound and temperature, throughout a cross-section of the material, which correlation is programmed into a computer to provide for a continuous in-process measurement of temperature throughout the specimen.

  11. TOUGH2: A general-purpose numerical simulator for multiphase fluid and heat flow

    SciTech Connect (OSTI)

    Pruess, K.

    1991-05-01T23:59:59.000Z

    TOUGH2 is a numerical simulation program for nonisothermal flows of multicomponent, multiphase fluids in porous and fractured media. The chief applications for which TOUGH2 is designed are in geothermal reservoir engineering, nuclear waste disposal, and unsaturated zone hydrology. A successor to the TOUGH program, TOUGH2 offers added capabilities and user features, including the flexibility to handle different fluid mixtures, facilities for processing of geometric data (computational grids), and an internal version control system to ensure referenceability of code applications. This report includes a detailed description of governing equations, program architecture, and user features. Enhancements in data inputs relative to TOUGH are described, and a number of sample problems are given to illustrate code applications. 46 refs., 29 figs., 12 tabs.

  12. Permeable Reactive Barriers | Department of Energy

    Energy Savers [EERE]

    in the barrier, a chemical reaction occurs with the barrier material that results in adsorption, mineral precipitation, or degradation to a harmless compound. Reactive barriers...

  13. Rejuvenating Permeable Reactive Barriers by Chemical Flushing

    Broader source: Energy.gov [DOE]

    Final Report:Rejuvenating Permeable Reactive Barriers by Chemical Flushing,U.S. Environmental Protection Agency, Region 8 Support.August 2004

  14. UNDERGRADUATE FELLOWSHIP RECIPIENTS: Stephanie Freeman -Permanent Reactive

    E-Print Network [OSTI]

    Fay, Noah

    55 2003 UNDERGRADUATE FELLOWSHIP RECIPIENTS: Stephanie Freeman - Permanent Reactive Bio Engineering Andrew Hinnell - Improving Electrical Resistivity Tomography for Characterization of Non

  15. Comparison of Conventional Diesel and Reactivity Controlled...

    Broader source: Energy.gov (indexed) [DOE]

    DEER 10182012 Comparison of Conventional Diesel and Reactivity Controlled Compression Ignition (RCCI) Combustion in a Light-Duty Engine Rolf D. Reitz and Sage L. Kokjohn Engine...

  16. Characterization and Reactivity of Iron Nanoparticles Prepared...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    engineered remediation systems. However, the structural characteristics of the metal additives and mechanism responsible for changes in reactivity have not been fully elucidated....

  17. Exploring the reactivity of bacterial multicomponent monooxygenases

    E-Print Network [OSTI]

    Tinberg, Christine Elaine

    2010-01-01T23:59:59.000Z

    Chapter 1. Introduction: The Reactivity of Bacterial Multicomponent Monooxygenases Bacterial multicomponent monooxygenases constitute a remarkable family of enzymes that oxidize small, inert hydrocarbon substrates using ...

  18. Demonstration/Development of Reactivity Controlled Compression...

    Broader source: Energy.gov (indexed) [DOE]

    DemonstrationDevelopment of Reactivity Controlled Compression Ignition (RCCI) Combustion for High Efficiency, Low Emissions Vehicle Applications Dr. Rolf Reitz Wisconsin Engine...

  19. Application of a transient heat transfer model for bundled, multiphase pipelines

    SciTech Connect (OSTI)

    Brown, T.S.; Clapham, J.; Danielson, T.J.; Harris, R.G.; Erickson, D.D.

    1996-12-31T23:59:59.000Z

    A computer model has been developed which accurately describes transient heat transfer in pipeline bundles. An arbitrary number of internal pipelines containing different fluids, flowing in either direction along with the input of heat to one or more of the fluids can be accommodated. The model is coupled to the transient, multiphase flow simulator OLGA. The lines containing the multiphase production fluids are modeled by OLGA, and the heat transfer between the internal lines, carrier pipe, and surroundings is handled by the bundle model. The model has been applied extensively to the design of a subsea, heated bundle system for the Britannia gas condensate field in the North Sea. The 15-km bundle system contains a 14{double_prime} production line, an 8{double_prime} test line, a 3{double_prime} methanol line, and a 12{double_prime} internal heating medium line within a 37.25{double_prime} carrier. The heating medium (water) flows in the internal heating medium line and in the annulus at 82,500 BPD. The primary purpose of the bundle system is to avoid the formation of hydrates. A secondary purpose is to avoid the deposition of paraffin. The bundle model was used to (1) compare the merits of two coaxial lines vs. a single bundle; (2) optimize the insulation levels on the carrier and internal lines; (3) determine the minimum time required to heat up the bundle; (4) determine heat input requirements to avoid hydrates throughout the field life, (5) determine temperature profiles along the lines for a range of production rates; (6) study ruptures of the production line into the bundle annulus; (7) determine minimum temperatures during depressurization; and (8) determine cool-down times. The results of these studies were used to size lines, select insulation levels, assess erosion potential, design for thermal expansion-induced stresses, and to select materials of construction.

  20. Method and system for measuring multiphase flow using multiple pressure differentials

    DOE Patents [OSTI]

    Fincke, James R. (Idaho Falls, ID)

    2001-01-01T23:59:59.000Z

    An improved method and system for measuring a multiphase flow in a pressure flow meter. An extended throat venturi is used and pressure of the multiphase flow is measured at three or more positions in the venturi, which define two or more pressure differentials in the flow conduit. The differential pressures are then used to calculate the mass flow of the gas phase, the total mass flow, and the liquid phase. The method for determining the mass flow of the high void fraction fluid flow and the gas flow includes certain steps. The first step is calculating a gas density for the gas flow. The next two steps are finding a normalized gas mass flow rate through the venturi and computing a gas mass flow rate. The following step is estimating the gas velocity in the venturi tube throat. The next step is calculating the pressure drop experienced by the gas-phase due to work performed by the gas phase in accelerating the liquid phase between the upstream pressure measuring point and the pressure measuring point in the venturi throat. Another step is estimating the liquid velocity in the venturi throat using the calculated pressure drop experienced by the gas-phase due to work performed by the gas phase. Then the friction is computed between the liquid phase and a wall in the venturi tube. Finally, the total mass flow rate based on measured pressure in the venturi throat is calculated, and the mass flow rate of the liquid phase is calculated from the difference of the total mass flow rate and the gas mass flow rate.

  1. DENSE MULTIPHASE FLOW SIMULATION: CONTINUUM MODEL FOR POLY-DISPERSED SYSTEMS USING KINETIC THEORY

    SciTech Connect (OSTI)

    Moses Bogere

    2011-08-31T23:59:59.000Z

    The overall objective of the project was to verify the applicability of the FCMOM approach to the kinetic equations describing the particle flow dynamics. For monodispersed systems the fundamental equation governing the particle flow dynamics is the Boltzmann equation. During the project, the FCMOM was successfully applied to several homogeneous and in-homogeneous problems in different flow regimes, demonstrating that the FCMOM has the potential to be used to solve efficiently the Boltzmann equation. However, some relevant issues still need to be resolved, i.e. the homogeneous cooling problem (inelastic particles cases) and the transition between different regimes. In this report, the results obtained in homogeneous conditions are discussed first. Then a discussion of the validation results for in-homogeneous conditions is provided. And finally, a discussion will be provided about the transition between different regimes. Alongside the work on development of FCMOM approach studies were undertaken in order to provide insights into anisotropy or particles kinetics in riser hydrodynamics. This report includes results of studies of multiphase flow with unequal granular temperatures and analysis of momentum re-distribution in risers due to particle-particle and fluid-particle interactions. The study of multiphase flow with unequal granular temperatures entailed both simulation and experimental studies of two particles sizes in a riser and, a brief discussion of what was accomplished will be provided. And finally, a discussion of the analysis done on momentum re-distribution of gas-particles flow in risers will be provided. In particular a discussion of the remaining work needed in order to improve accuracy and predictability of riser hydrodynamics based on two-fluid models and how they can be used to model segregation in risers.

  2. Multi-Phased, Post-Accident Support of the Fukushima Dai-Ichi Nuclear Power Plant - 12246

    SciTech Connect (OSTI)

    Gay, Arnaud; Gillet, Philippe; Ytournel, Bertrand; Varet, Thierry; David, Laurent; Prevost, Thierry; Redonnet, Carol; Piot, Gregoire; Jouaville, Stephane; Pagis, Georges [AREVA NC (France)

    2012-07-01T23:59:59.000Z

    In the wake of the March 11 earthquake and tsunami and the subsequent flooding of several of the Fukushima Dai-Ichi reactors, Japan and the Japanese utility TEPCO faced a crisis situation with incredible challenges: substantial amounts of radioactive mixed seawater and freshwater accumulated in the basements of four reactor and other buildings on the site. This water held varying levels of contamination due to the fact that it had been in contact with damaged fuel elements in the cores and with other contaminated components. The overall water inventory was estimated at around 110,000 tons of water with contamination levels up to the order of 1 Ci/l. Time was of the essence to avoid overflow of this accumulated water into the ocean. AREVA proposed, designed and implemented a water treatment solution using a proven chemical coprecipitation process with ppFeNi reagent, which is currently in use for effluent treatment on several nuclear sites including AREVA sites. In addition to the extremely short schedule the other challenge was to adapt the chemical treatment process to the expected composition of the Fukushima water and, in particular, to evaluate the impact of salinity on process performance. It was also necessary to define operating conditions for the VEOLIA equipment that had been selected for implementation of the process in the future facility. The operation phase began on June 17, and by the end of July more than 30,000 tons of highly radioactive saltwater had been decontaminated - the Decontamination Factor (DF) for Cesium was ?10{sup 4}. It allowed recycling the contaminated water to cool the reactors while protecting workers and the environment. This paper focuses on the Actiflo{sup TM}-Rad water treatment unit project that was part of the TEPCO general water treatment scheme. It presents a detailed look at the principles of the Actiflo{sup TM}-Rad, related on-the-fly R and D, an explanation of system implementation challenges, and a brief summary of operation results to date. AREVA's response to the Fukushima Dai-Ichi crisis was multi-phased: emergency aid and relief supply was sent within days after the accident; AREVA-Veolia engineering teams designed and implemented a water treatment solution in record time, only 3 months; and AREVA continues to support TEPCO and propose solutions for waste management, soil remediation and decontamination of the Fukushima Dai-Ichi site. Despite the huge challenges, the Actiflo{sup TM}-Rad project has been a success: the water treatment unit started on time and performed as expected. The performance is the result of many key elements: AREVA expertise in radioactive effluents decontamination, Veolia know-how in water treatment equipments in crisis environment, and of course AREVA and Veolia teams' creativity. The project success is also due to AREVA and Veolia teams' reactivity and high level of commitment with engineering teams working 24/7 in Japan, France and Germany. AREVA and Veolia deep knowledge of the Japanese industry ensured that the multi-cultural exchanges were not an issue. Finally the excellent overall project management and execution by TEPCO and other Japanese stakeholders was very efficient. The emergency water treatment was a key step of the roadmap towards restoration from the accident at Fukushima Dai-Ichi that TEPCO designed and keeps executing with success. (authors)

  3. Method for reactivating catalysts and a method for recycling supercritical fluids used to reactivate the catalysts

    DOE Patents [OSTI]

    Ginosar, Daniel M. (Idaho Falls, ID); Thompson, David N. (Idaho Falls, ID); Anderson, Raymond P. (Idaho Falls, ID)

    2008-08-05T23:59:59.000Z

    A method of reactivating a catalyst, such as a solid catalyst or a liquid catalyst. 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.

  4. Reactive and non-reactive interactions of thiophene with WS2...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    interactions of thiophene with WS2 fullerene-like nanoparticles: an ultra-high vacuum surface Reactive and non-reactive interactions of thiophene with WS2 fullerene-like...

  5. Investigation of the Effect of Non-Darcy Flow and Multi-Phase Flow on the Productivity of Hydraulically Fractured Gas Wells

    E-Print Network [OSTI]

    Alarbi, Nasraldin Abdulslam A.

    2011-10-21T23:59:59.000Z

    an optimum stimulation treatment that leads to the maximum possible productivity. These considerations include, but not limited to, non-Darcy flow and multiphase flow effects inside the fracture. These effects reduce the fracture conductivity significantly...

  6. Reactive Power Support Services in Electricity Markets

    E-Print Network [OSTI]

    Reactive Power Support Services in Electricity Markets Costing and Pricing of Ancillary Services Reactive Power Support Services in Electricity Markets Costing and Pricing of Ancillary Services Project this Project For information about this project contact: Peter W. Sauer, Project Leader Professor Electrical

  7. REACTIVE LOAD MODELINGIMPACTS ONNODAL PRICESINPOOL MODELELECTRICITYMARKETS

    E-Print Network [OSTI]

    Gross, George

    REACTIVE LOAD MODELINGIMPACTS ONNODAL PRICESINPOOL MODELELECTRICITYMARKETS EttoreBompard, Enrico of the nodal prices in competitive electricity markets based on the Pool paradigm. Such prices focus of the paper is on the explicit evaluation of the impactsof the reactive load onthenodal real

  8. REACTIVE ENVIRONMENTS AND AUGMENTED MEDIA SPACES

    E-Print Network [OSTI]

    Cooperstock, Jeremy R.

    REACTIVE ENVIRONMENTS AND AUGMENTED MEDIA SPACES by Jeremy R. Cooperstock A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Graduate Department of Electrical and Computer Engineering University of Toronto © Copyright by Jeremy R. Cooperstock, 1996 #12;ii REACTIVE

  9. PFLOTRAN: Reactive Flow & Transport Code for Use on Laptops to Leadership-Class Supercomputers

    SciTech Connect (OSTI)

    Hammond, Glenn E.; Lichtner, Peter C.; Lu, Chuan; Mills, Richard T.

    2012-04-18T23:59:59.000Z

    PFLOTRAN, a next-generation reactive flow and transport code for modeling subsurface processes, has been designed from the ground up to run efficiently on machines ranging from leadership-class supercomputers to laptops. Based on an object-oriented design, the code is easily extensible to incorporate additional processes. It can interface seamlessly with Fortran 9X, C and C++ codes. Domain decomposition parallelism is employed, with the PETSc parallel framework used to manage parallel solvers, data structures and communication. Features of the code include a modular input file, implementation of high-performance I/O using parallel HDF5, ability to perform multiple realization simulations with multiple processors per realization in a seamless manner, and multiple modes for multiphase flow and multicomponent geochemical transport. Chemical reactions currently implemented in the code include homogeneous aqueous complexing reactions and heterogeneous mineral precipitation/dissolution, ion exchange, surface complexation and a multirate kinetic sorption model. PFLOTRAN has demonstrated petascale performance using 2{sup 17} processor cores with over 2 billion degrees of freedom. Accomplishments achieved to date include applications to the Hanford 300 Area and modeling CO{sub 2} sequestration in deep geologic formations.

  10. Reactive Support and Voltage Control Service: Key Issues and Challenges

    E-Print Network [OSTI]

    Gross, George

    reactive support and voltage control services. Keywords ­ Competitive Electricity Markets, Reactive PowerReactive Support and Voltage Control Service: Key Issues and Challenges George Gross^, Paolo Marannino° and Gianfranco Chicco* ^ Department of Electrical and Computer Engineering, University

  11. A smoothed particle hydrodynamics model for reactive transport...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A smoothed particle hydrodynamics model for reactive transport and mineral precipitation in porous and fractured porous media. A smoothed particle hydrodynamics model for reactive...

  12. Assessment of Controlling Processes for Field-Scale Uranium Reactive...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    reactive transport model was employed to assess the key factors and processes that control the field-scale uranium reactive transport. Taking into consideration of relevant...

  13. Characterization of Dual-Fuel Reactivity Controlled Compression...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Dual-Fuel Reactivity Controlled Compression Ignition (RCCI) Using Hydrated Ethanol and Diesel Fuel Characterization of Dual-Fuel Reactivity Controlled Compression Ignition (RCCI)...

  14. Field Demonstration Of Permeable Reactive Barriers To Remove

    E-Print Network [OSTI]

    Field Demonstration Of Permeable Reactive Barriers To Remove Dissolved Uranium From Groundwater-001 November 2000 FIELD DEMONSTRATION OF PERMEABLE REACTIVE BARRIERS TO REMOVE DISSOLVED URANIUM FROM

  15. Comparison of Conventional Diesel and Reactivity Controlled Compressio...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Conventional Diesel and Reactivity Controlled Compression Ignition (RCCI) Combustion in a Light-Duty Engine Comparison of Conventional Diesel and Reactivity Controlled Compression...

  16. Enrichment of Functional Redox Reactive Proteins and Identification...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Redox Reactive Proteins and Identification by Mass Spectrometry Results in Several Terminal Fe(III) Enrichment of Functional Redox Reactive Proteins and Identification by Mass...

  17. Microscopic Reactive Diffusion of Uranium in the Contaminated...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Reactive Diffusion of Uranium in the Contaminated Sediments at Hanford, United States. Microscopic Reactive Diffusion of Uranium in the Contaminated Sediments at Hanford, United...

  18. Role of Point Defects on the Reactivity of Reconstructed Anatase...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Point Defects on the Reactivity of Reconstructed Anatase Titanium Dioxide (001) Surface. Role of Point Defects on the Reactivity of Reconstructed Anatase Titanium Dioxide (001)...

  19. Parameter estimation from flowing fluid temperature logging data in unsaturated fractured rock using multiphase inverse modeling

    SciTech Connect (OSTI)

    Mukhopadhyay, S.; Tsang, Y.; Finsterle, S.

    2009-01-15T23:59:59.000Z

    A simple conceptual model has been recently developed for analyzing pressure and temperature data from flowing fluid temperature logging (FFTL) in unsaturated fractured rock. Using this conceptual model, we developed an analytical solution for FFTL pressure response, and a semianalytical solution for FFTL temperature response. We also proposed a method for estimating fracture permeability from FFTL temperature data. The conceptual model was based on some simplifying assumptions, particularly that a single-phase airflow model was used. In this paper, we develop a more comprehensive numerical model of multiphase flow and heat transfer associated with FFTL. Using this numerical model, we perform a number of forward simulations to determine the parameters that have the strongest influence on the pressure and temperature response from FFTL. We then use the iTOUGH2 optimization code to estimate these most sensitive parameters through inverse modeling and to quantify the uncertainties associated with these estimated parameters. We conclude that FFTL can be utilized to determine permeability, porosity, and thermal conductivity of the fracture rock. Two other parameters, which are not properties of the fractured rock, have strong influence on FFTL response. These are pressure and temperature in the borehole that were at equilibrium with the fractured rock formation at the beginning of FFTL. We illustrate how these parameters can also be estimated from FFTL data.

  20. Visualizing multiphase flow and trapped fluid configurations in a model three-dimensional porous medium

    E-Print Network [OSTI]

    Amber T. Krummel; Sujit S. Datta; Stefan Münster; David A. Weitz

    2013-01-21T23:59:59.000Z

    We report an approach to fully visualize the flow of two immiscible fluids through a model three-dimensional (3D) porous medium at pore-scale resolution. Using confocal microscopy, we directly image the drainage of the medium by the non-wetting oil and subsequent imbibition by the wetting fluid. During imbibition, the wetting fluid pinches off threads of oil in the narrow crevices of the medium, forming disconnected oil ganglia. Some of these ganglia remain trapped within the medium. By resolving the full 3D structure of the trapped ganglia, we show that the typical ganglion size, and the total amount of residual oil, decreases as the capillary number Ca increases; this behavior reflects the competition between the viscous pressure in the wetting fluid and the capillary pressure required to force oil through the pores of the medium. This work thus shows how pore-scale fluid dynamics influence the trapped fluid configurations in multiphase flow through 3D porous media.

  1. Application of a geocentrifuge and sterolithographically fabricated apertures to multiphase flow in complex fracture apertures.

    SciTech Connect (OSTI)

    Glenn E. McCreery; Robert D. Stedtfeld; Alan T. Stadler; Daphne L. Stoner; Paul Meakin

    2005-09-01T23:59:59.000Z

    A geotechnical centrifuge was used to investigate unsaturated multiphase fluid flow in synthetic fracture apertures under a variety of flow conditions. The geocentrifuge subjected the fluids to centrifugal forces allowing the Bond number to be systematically changed without adjusting the fracture aperture of the fluids. The fracture models were based on the concept that surfaces generated by the fracture of brittle geomaterials have a self-affine fractal geometry. The synthetic fracture surfaces were fabricated from a transparent epoxy photopolymer using sterolithography, and fluid flow through the transparent fracture models was monitored by an optical image acquisition system. Aperture widths were chosen to be representative of the wide range of geological fractures in the vesicular basalt that lies beneath the Idaho Nation Laboratory (INL). Transitions between different flow regimes were observed as the acceleration was changed under constant flow conditions. The experiments showed the transition between straight and meandering rivulets in smooth walled apertures (aperture width = 0.508 mm), the dependence of the rivulet width on acceleration in rough walled fracture apertures (average aperture width = 0.25 mm), unstable meandering flow in rough walled apertures at high acceleration (20g) and the narrowing of the wetted region with increasing acceleration during the penetration of water into an aperture filled with wetted particles (0.875 mm diameter glass spheres).

  2. Thickness-based adaptive mesh refinement methods for multi-phase flow simulations with thin regions

    SciTech Connect (OSTI)

    Chen, Xiaodong [The State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Yang, Vigor, E-mail: vigor.yang@aerospace.gatech.edu [School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0150 (United States)

    2014-07-15T23:59:59.000Z

    In numerical simulations of multi-scale, multi-phase flows, grid refinement is required to resolve regions with small scales. A notable example is liquid-jet atomization and subsequent droplet dynamics. It is essential to characterize the detailed flow physics with variable length scales with high fidelity, in order to elucidate the underlying mechanisms. In this paper, two thickness-based mesh refinement schemes are developed based on distance- and topology-oriented criteria for thin regions with confining wall/plane of symmetry and in any situation, respectively. Both techniques are implemented in a general framework with a volume-of-fluid formulation and an adaptive-mesh-refinement capability. The distance-oriented technique compares against a critical value, the ratio of an interfacial cell size to the distance between the mass center of the cell and a reference plane. The topology-oriented technique is developed from digital topology theories to handle more general conditions. The requirement for interfacial mesh refinement can be detected swiftly, without the need of thickness information, equation solving, variable averaging or mesh repairing. The mesh refinement level increases smoothly on demand in thin regions. The schemes have been verified and validated against several benchmark cases to demonstrate their effectiveness and robustness. These include the dynamics of colliding droplets, droplet motions in a microchannel, and atomization of liquid impinging jets. Overall, the thickness-based refinement technique provides highly adaptive meshes for problems with thin regions in an efficient and fully automatic manner.

  3. Discrete modelling of capillary mechanisms in multi-phase granular media

    E-Print Network [OSTI]

    L. Scholtès; B. Chareyre F. Nicot; F. Darve

    2012-03-06T23:59:59.000Z

    A numerical study of multi-phase granular materials based upon micro-mechanical modelling is proposed. Discrete element simulations are used to investigate capillary induced effects on the friction properties of a granular assembly in the pendular regime. Capillary forces are described at the local scale through the Young-Laplace equation and are superimposed to the standard dry particle interaction usually well simulated through an elastic-plastic relationship. Both effects of the pressure difference between liquid and gas phases and of the surface tension at the interface are integrated into the interaction model. Hydraulic hysteresis is accounted for based on the possible mechanism of formation and breakage of capillary menisci at contacts. In order to upscale the interparticular model, triaxial loading paths are simulated on a granular assembly and the results interpreted through the Mohr-Coulomb criterion. The micro-mechanical approach is validated with a capillary cohesion induced at the macroscopic scale. It is shown that interparticular menisci contribute to the soil resistance by increasing normal forces at contacts. In addition, more than the capillary pressure level or the degree of saturation, our findings highlight the importance of the density number of liquid bonds on the overall behaviour of the material.

  4. MODELING COUPLED PROCESSES OF MULTIPHASE FLOW AND HEAT TRANSFER IN UNSATURATED FRACTURED ROCK

    SciTech Connect (OSTI)

    Y. Wu; S. Mukhopadhyay; K. Zhang; G.S. Bodvarsson

    2006-02-28T23:59:59.000Z

    A mountain-scale, thermal-hydrologic (TH) numerical model is developed for investigating unsaturated flow behavior in response to decay heat from the radioactive waste repository at Yucca Mountain, Nevada, USA. The TH model, consisting of three-dimensional (3-D) representations of the unsaturated zone, is based on the current repository design, drift layout, and thermal loading scenario under estimated current and future climate conditions. More specifically, the TH model implements the current geological framework and hydrogeological conceptual models, and incorporates the most updated, best-estimated input parameters. This mountain-scale TH model simulates the coupled TH processes related to mountain-scale multiphase fluid flow, and evaluates the impact of radioactive waste heat on the hydrogeological system, including thermally perturbed liquid saturation, gas- and liquid-phase fluxes, and water and rock temperature elevations, as well as the changes in water flux driven by evaporation/condensation processes and drainage between drifts. For a better description of the ambient geothermal condition of the unsaturated zone system, the TH model is first calibrated against measured borehole temperature data. The ambient temperature calibration provides the necessary surface and water table boundary as well as initial conditions. Then, the TH model is used to obtain scientific understanding of TH processes in the Yucca Mountain unsaturated zone under the designed schedule of repository thermal load.

  5. Analysis of a multiphase, porous-flow imbibition experiment in fractured volcanic tuff

    SciTech Connect (OSTI)

    Eaton, R.R.; Bixler, N.E.

    1986-12-31T23:59:59.000Z

    A sub-meter-scale imbibition experiment has been analyzed using a finite element, multiphase-flow code. In the experiment, an initially dry cylindrical core of fractured volcanic tuff was saturated by contacting the ends with pressurized water. Our model discretely accounts for three primary fractures that may be present in the core, as indicated by measurements of porosity and saturation. We show that vapor transport has a small (less than 5%) effect on the speed of the wetting front. By using experimental results to estimate apparent spatial variations in permeability along the core, good agreement with measured, transient, saturation data was achieved. The sensitivity of predicted transient wetting fronts to permeability data indicates a need for more extensive measurements. We conclude that it will be difficult to characterize an entire repository - where inhomogeneities due to variations in matrix and fracture properties are not well known - solely from the results of sub-meter-scale laboratory testing and deterministic modeling. 16 refs., 8 figs., 1 tab.

  6. Drying analysis of a multiphase, porous-flow experiment in fractured volcanic tuff

    SciTech Connect (OSTI)

    Bixler, N.E.; Eaton, R.R.; Russo, A.J.

    1987-12-31T23:59:59.000Z

    A submeter-scale drying experiment has been analyzed using a finite element, multiphase-flow code. In the experiment, an initially wet cylindrical core of fractured volcanic tuff was dried by blowing dry nitrogen over the ends. Our model discretely accounts for three primary fractures that may be present in the core, as indicated by measurements of porosity and saturation. We show that vapor transport is unimportant in the interior of the core; the rate of drying is controlled by transport of liquid water to the ends of the core, where it can evaporate and escape into the dry environment outside. By using previous experimental results to estimate apparent spatial variations in permeability along the core, good agreement between measured and calculated drying rates was achieved. However, predicted saturation profiles were much smoother that those measured experimentally, presumably because of centimeter-scale inhomogeneities in the core sample. Our results indicate that water is transported chiefly as liquid from the interior to the edges of the core, where it evaporates and escapes out the ends. Thus, liquid-phase transport controls the overall drying rate. 18 refs., 8 figs., 1 tab.

  7. Modeling multiphase heat and mass transfer in consolidated, fractured, porous media

    SciTech Connect (OSTI)

    Bixler, N.E.; Eaton, R.R.

    1987-12-31T23:59:59.000Z

    A number of potential transport mechanisms are considered in this paper: Darcy flow due to pressure and density gradients in the liquid and gas phases; Knudsen diffusion in the gas phase; binary diffusion in the gas phase; heat conduction; energy convection; and evaporation/condensation and its associated latent heat effects. Most of these mechanisms are highly nonlinear, especially Darcy flow, where relative permeabilities often vary by orders of magnitude depending on local saturation, and evaporation/condensation, which depends strongly on local temperature, gas pressure, and saturation. As a consequence of the nonlinearities, it is essential to employ numerical methods if realistic modeling is to be performed. Here, the numerical model is of the standard Galerkin/finite element variety, which is convenient for handling irregular domains and a wide variety of boundary conditions. This numerical model is used to examine the relative effectiveness of each of the transport mechanisms in several one-dimensional and simple two-dimensional multiphase flows in fractured and unfractured porous materials. The importance of fracture orientation is also studied. Predictions are compared with experimental measurements for imbibition and drying of fractured volcanic tuff.

  8. Groundwater well with reactive filter pack

    DOE Patents [OSTI]

    Gilmore, Tyler J. (Pasco, WA); Holdren, Jr., George R. (Kennewick, WA); Kaplan, Daniel I. (Richland, WA)

    1998-01-01T23:59:59.000Z

    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.

  9. A Tariff for Reactive Power - IEEE

    SciTech Connect (OSTI)

    Kueck, John D [ORNL; Tufon, Christopher [Pacific Gas and Electric Company; Isemonger, Alan [California Independent System Operator; Kirby, Brendan J [ORNL

    2008-11-01T23:59:59.000Z

    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.

  10. Reactivity control assembly for nuclear reactor

    DOE Patents [OSTI]

    Bollinger, Lawrence R. (Schenectady, NY)

    1984-01-01T23:59:59.000Z

    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.

  11. Systematic approach for chemical reactivity evaluation

    E-Print Network [OSTI]

    Aldeeb, Abdulrehman Ahmed

    2004-09-30T23:59:59.000Z

    , 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...

  12. Groundwater well with reactive filter pack

    DOE Patents [OSTI]

    Gilmore, T.J.; Holdren, G.R. Jr.; Kaplan, D.I.

    1998-09-08T23:59:59.000Z

    A method and apparatus are disclosed 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. 3 figs.

  13. EPA/ITRC-RTDF permeable reactive barrier short course. Permeable reactive barriers: Application and deployment

    SciTech Connect (OSTI)

    Not Available

    1999-01-01T23:59:59.000Z

    This report focuses on the following: Permeable Reactive Barriers: Application and Deployment; Introduction to Permeable Reactive Barriers (PRBs) for Remediating and Managing Contaminated Groundwater in Situ; Collection and Interpretation of Design Data 1: Site Characterization for PRBs; Reactive Materials: Zero-Valent Iron; Collection and Interpretation of Design Data 2: Laboratory and Pilot Scale Tests; Design Calculations; Compliance Monitoring, Performance Monitoring and Long-Term Maintenance for PRBs; PRB Emplacement Techniques; PRB Permitting and Implementation; Treatment of Metals; Non-Metallic Reactive Materials; Economic Considerations for PRB Deployment; and Bibliography.

  14. EPA/ITRC-RTDF permeable reactive barrier short course. Permeable reactive barriers: Application and deployment

    SciTech Connect (OSTI)

    NONE

    1999-11-01T23:59:59.000Z

    This report focuses on the following: Permeable Reactive Barriers: Application and Deployment; Introduction to Permeable Reactive Barriers (PRBs) for Remediating and Managing Contaminated Groundwater in Situ; Collection and Interpretation of Design Data 1: Site Characterization for PRBs; Reactive Materials: Zero-Valent Iron; Collection and Interpretation of Design Data 2: Laboratory and Pilot Scale Tests; Design Calculations; Compliance Monitoring, Performance Monitoring and Long-Term Maintenance for PRBs; PRB Emplacement Techniques; PRB Permitting and Implementation; Treatment of Metals; Non-Metallic Reactive Materials; Economic Considerations for PRB Deployment; and Bibliography.

  15. Eoeective Recognizability and Model Checking of Reactive Fioeo Automata

    E-Print Network [OSTI]

    Sutre, Grégoire

    Electre. For this, we deøne a particular behavioral model for Electre programs, Reactive Fioeo Au­ tomata speciøed with the reactive language Electre [CR95]. A reactive pro­ gram is supposed to reactEoeective Recognizability and Model Checking of Reactive Fioeo Automata G. Sutre 1 , A. Finkel 1

  16. Seismic signatures of multiphase reservoir fluid distributions: Application to reservoir monitoring

    SciTech Connect (OSTI)

    Packwood, J.L.; Mavko, G.M.

    1995-12-31T23:59:59.000Z

    We present an investigation of the effect of multi-phase pore fluid distributions on the seismic velocity of saturated rock as a function of temperature and pressure. The purpose is to show how different fluid distributions might result in different seismic signatures. This is the rock physics link between reservoir simulation and seismic monitoring of hydrocarbon; (1) Uniform effective fluid, (2) Fluid in patches, and (3) Laminated fluid. The latter two models have heterogeneous distributions, and demonstrate that they have the same velocity characteristics. We used Beaver sandstone with a porosity of 6.4% and 5 MPa confining pressure as the rock matrix for our calculations. The uniform fluid model shows poor sensitivity to fluid saturation, with a variation in velocity of less than 1% when gas saturation exceeds 2%. The heterogeneous models show a fairly linear dependence of velocity on saturation with a variation of 7%. We also investigate the effect of oil distillation on seismic velocities during steam flooding. Comparisons velocities calculated using the patches model at temperature of 20{degrees}C and 150{degrees}C, the choice of hydrocarbon components is more critical at high values of oil saturation than at low values of oil saturation. In regions of high oil saturation, there is less than 0.5% variation in velocity using these components. The velocity variation using the effective fluid model at the same conditions is less than 0.5% over the entire range of gas saturation greater than 2%, indicating that the choice of hydrocarbons is not as critical as in the patches model.

  17. Reaction plane angle dependence of dihadron azimuthal correlations from a multiphase transport model calculation

    E-Print Network [OSTI]

    W. Li; S. Zhang; Y. G. Ma; X. Z. Cai; J. H. Chen; H. Z. Huang; G. L. Ma; C. Zhong

    2010-01-07T23:59:59.000Z

    Dihadron azimuthal angle correlations relative to the reaction plane have been investigated in Au + Au collisions at $\\sqrt{s_{NN}}$ = 200 GeV using a multi-phase transport model (AMPT). Such reaction plane azimuthal angle dependent correlations can shed light on path-length effect of energy loss of high transverse momentum particles propagating through the hot dense medium. The correlations vary with the trigger particle azimuthal angle with respect to the reaction plane direction, $\\phi_{s}=\\phi_{T}-\\Psi_{EP}$, which is consistent with the experimental observation by the STAR collaboration. The dihadron azimuthal angle correlation functions on the away side of the trigger particle present a distinct evolution from a single peak to a broad, possibly double peak, structure when the trigger particle direction goes from in-plane to out-of-plane of the reaction plane. The away-side angular correlation functions are asymmetric with respect to the back-to-back direction in some regions of $\\phi_{s}$, which could provide insight on testing $v_{1}$ method to reconstruct the reaction plane. In addition, both the root-mean-square width ($W_{rms}$) of the away-side correlation distribution and the splitting parameter $D$ between the away-side double peaks increase slightly with $\\phi_{s}$, and the average transverse momentum of the away-side associated hadrons shows a strong $\\phi_{s}$ dependence. Our results indicate that strong parton cascade and resultant energy loss could play an important role for the appearance of a double-peak structure in the dihadron azimuthal angular correlation function on the away side of the trigger particle.

  18. The Multiphase Halo of NGC 891: WIYN H-alpha and BVI Imaging

    E-Print Network [OSTI]

    J. Christopher Howk; Blair D. Savage

    1999-10-14T23:59:59.000Z

    We present new, deep optical images (BVI+H-alpha) of the interstellar medium (ISM) far above the plane of NGC 891. These sub-arcsecond images give a direct visual view of two physically distinct ``phases'' of the thick interstellar disk of this galaxy. A dense phase of the thick disk ISM is observed in our BVI images as highly-structured dust-bearing clouds viewed against the stellar light of the galaxy. These structures are traceable to heights |z|=2 kpc from the midplane. Very few highly-structured dust features are present at |z|>2 kpc. The more prominent dust structures have gas masses in excess of 10^5 solar masses, each having visual extinctions well in excess of unity. A warm ionized phase of the high-z ISM is observed through its well-studied H-alpha emission. Our images of the well-studied diffuse ionized medium, to date the highest-resolution observations of this phase of the ISM in NGC 891, show it is relatively smoothly distributed with some filamentary structure superposed on this smooth background. There is little correspondence between the H-alpha emitting material and the absorbing dust structures. These two phases of the multiphase high-z ISM are physically distinct. The H-alpha emission is being heavily extincted in many places by the dense dust-bearing medium. Our H-alpha observations show evidence for several discrete H II regions at large distances from the midplane (to |z|=2 kpc). The presence of these H II regions in the thick disk of NGC 891 suggests that on-going star formation may be present in some of the dense, high-z clouds visible in our images. (Abstract Abridged)

  19. Numerical modeling of multiphase plumes: a comparative study between two-fluid and mixed-fluid integral models

    E-Print Network [OSTI]

    Bhaumik, Tirtharaj

    2005-11-01T23:59:59.000Z

    -field effects of a multiphase plume of liquid CO2 droplets in ocean water finds potential in estimating the environmental risks involved due to deep-ocean sequestration of greenhouse gases like carbon dioxide, which is one of the proposed alternatives (Liro... for the diffuser orifice diameter, air-flow rate and the number of such ports necessary to dissolve a measured quantity of air in a given time of operation will also be studied. 3.3. Case 3: CO2 Sequestration in the Ocean Sequestration of carbon dioxide and other...

  20. Study of triangular flow $v_3$ in Au+Au and Cu+Cu collisions with a multiphase transport model

    E-Print Network [OSTI]

    Kai Xiao; Na Li; Shusu Shi; Feng Liu

    2012-01-13T23:59:59.000Z

    We studied the relation between the initial geometry anisotropy and the anisotropic flow in a multiphase transport model (AMPT) for both Au+Au and Cu+Cu collisions at $\\sqrt{s_{NN}}$ = 200 GeV. It is found that unlike the elliptic flow $v_2$, little centrality dependence of the triangular flow $v_3$ is observed. After removing the initial geometry effect, $v_3/\\epsilon_3$ increases with the transverse particle density, which is similar to $v_2/\\epsilon_2$. The transverse momentum ($p_T$) dependence of $v_3$ from identified particles is qualitatively similar to the $p_T$ dependence of $v_2$.

  1. Multiphase Flow Metering: An Overview Manoj Kumar KM, Senior Scientist, Non-destructive Evaluation Lab, GE Global Research,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighandSWPA / SPRA /Ml'.SolarUS DeptMultilateralMultimediaScienceMultiphase

  2. Method For Reactivating Solid Catalysts Used For Alklation Reactions

    DOE Patents [OSTI]

    Ginosar, Daniel M. (Idaho Falls, ID); Thompson, David N. (Idaho Falls, ID); Coates, Kyle (Shelley, ID); Zalewski, David J. (Proctorville, OH); Fox, Robert V. (Idaho Falls, ID)

    2005-05-03T23:59:59.000Z

    A method for reactivating a solid alkylation catalyst is provided which can be performed within a reactor that contains the alkylation catalyst or outside the reactor. Effective catalyst reactivation is achieved whether the catalyst is completely deactivated or partially deactivated. A fluid reactivating agent is employed to dissolve catalyst fouling agents and also to react with such agents and carry away the reaction products. The deactivated catalyst is contacted with the fluid reactivating agent under pressure and temperature conditions such that the fluid reactivating agent is dense enough to effectively dissolve the fouling agents and any reaction products of the fouling agents and the reactivating agent. Useful pressures and temperatures for reactivation include near-critical, critical, and supercritical pressures and temperatures for the reactivating agent. The fluid reactivating agent can include, for example, a branched paraffin containing at least one tertiary carbon atom, or a compound that can be isomerized to a molecule containing at least one tertiary carbon atom.

  3. Method for reactivating solid catalysts used in alkylation reactions

    DOE Patents [OSTI]

    Ginosar, Daniel M.; Thompson, David N.; Coates, Kyle; Zalewski, David J.; Fox, Robert V.

    2003-06-17T23:59:59.000Z

    A method for reactivating a solid alkylation catalyst is provided which can be performed within a reactor that contains the alkylation catalyst or outside the reactor. Effective catalyst reactivation is achieved whether the catalyst is completely deactivated or partially deactivated. A fluid reactivating agent is employed to dissolve catalyst fouling agents and also to react with such agents and carry away the reaction products. The deactivated catalyst is contacted with the fluid reactivating agent under pressure and temperature conditions such that the fluid reactivating agent is dense enough to effectively dissolve the fouling agents and any reaction products of the fouling agents and the reactivating agent. Useful pressures and temperatures for reactivation include near-critical, critical, and supercritical pressures and temperatures for the reactivating agent. The fluid reactivating agent can include, for example, a branched paraffin containing at least one tertiary carbon atom, or a compound that can be isomerized to a molecule containing at least one tertiary carbon atom.

  4. Water reactive hydrogen fuel cell power system

    DOE Patents [OSTI]

    Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

    2014-01-21T23:59:59.000Z

    A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into a fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

  5. Water reactive hydrogen fuel cell power system

    DOE Patents [OSTI]

    Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

    2014-11-25T23:59:59.000Z

    A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into the fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

  6. Effect of wettability on scale-up of multiphase flow from core-scale to reservoir fine-grid-scale

    SciTech Connect (OSTI)

    Chang, Y.C.; Mani, V.; Mohanty, K.K. [Univ. of Houston, TX (United States)

    1997-08-01T23:59:59.000Z

    Typical field simulation grid-blocks are internally heterogeneous. The objective of this work is to study how the wettability of the rock affects its scale-up of multiphase flow properties from core-scale to fine-grid reservoir simulation scale ({approximately} 10{prime} x 10{prime} x 5{prime}). Reservoir models need another level of upscaling to coarse-grid simulation scale, which is not addressed here. Heterogeneity is modeled here as a correlated random field parameterized in terms of its variance and two-point variogram. Variogram models of both finite (spherical) and infinite (fractal) correlation length are included as special cases. Local core-scale porosity, permeability, capillary pressure function, relative permeability functions, and initial water saturation are assumed to be correlated. Water injection is simulated and effective flow properties and flow equations are calculated. For strongly water-wet media, capillarity has a stabilizing/homogenizing effect on multiphase flow. For small variance in permeability, and for small correlation length, effective relative permeability can be described by capillary equilibrium models. At higher variance and moderate correlation length, the average flow can be described by a dynamic relative permeability. As the oil wettability increases, the capillary stabilizing effect decreases and the deviation from this average flow increases. For fractal fields with large variance in permeability, effective relative permeability is not adequate in describing the flow.

  7. Incorporation of Reaction Kinetics into a Multiphase, Hydrodynamic Model of a Fischer Tropsch Slurry Bubble Column Reactor

    SciTech Connect (OSTI)

    Donna Guillen, PhD; Anastasia Gribik; Daniel Ginosar, PhD; Steven P. Antal, PhD

    2008-11-01T23:59:59.000Z

    This paper describes the development of a computational multiphase fluid dynamics (CMFD) model of the Fischer Tropsch (FT) process in a Slurry Bubble Column Reactor (SBCR). The CMFD model is fundamentally based which allows it to be applied to different industrial processes and reactor geometries. The NPHASE CMFD solver [1] is used as the robust computational platform. Results from the CMFD model include gas distribution, species concentration profiles, and local temperatures within the SBCR. This type of model can provide valuable information for process design, operations and troubleshooting of FT plants. An ensemble-averaged, turbulent, multi-fluid solution algorithm for the multiphase, reacting flow with heat transfer was employed. Mechanistic models applicable to churn turbulent flow have been developed to provide a fundamentally based closure set for the equations. In this four-field model formulation, two of the fields are used to track the gas phase (i.e., small spherical and large slug/cap bubbles), and the other two fields are used for the liquid and catalyst particles. Reaction kinetics for a cobalt catalyst is based upon values reported in the published literature. An initial, reaction kinetics model has been developed and exercised to demonstrate viability of the overall solution scheme. The model will continue to be developed with improved physics added in stages.

  8. Synthesis of cubic niobium nitride by reactive diffusion under nitrogen pressure

    SciTech Connect (OSTI)

    Linde, A.V. [Institute of Structural Macrokinetics and Materials Science (ISMAN), Russian Academy of Sciences, Chernogolovka, Moscow 142432 (Russian Federation); Institut Charles Gerhardt Montpellier (ICGM), PMOF-UM2-CNRS, pl. E. Bataillon, 34095 Montpellier Cedex 5 (France); Marin-Ayral, R.-M. [Institut Charles Gerhardt Montpellier (ICGM), PMOF-UM2-CNRS, pl. E. Bataillon, 34095 Montpellier Cedex 5 (France)], E-mail: rose-marie.ayral@univ-montp2.fr; Granier, D.; Bosc-Rouessac, F. [Institut Charles Gerhardt Montpellier (ICGM), PMOF-UM2-CNRS, pl. E. Bataillon, 34095 Montpellier Cedex 5 (France); Grachev, V.V. [Institute of Structural Macrokinetics and Materials Science (ISMAN), Russian Academy of Sciences, Chernogolovka, Moscow 142432 (Russian Federation)

    2009-05-06T23:59:59.000Z

    The synthesis of niobium nitride by reactive diffusion in a furnace at 1395-1475 deg. C and under nitrogen pressure in the range 2-25 MPa was investigated. In experiments, we used compacted Nb powder with a mean particle size of 43 {mu}m. Phase transformations in the product as studied by electron probe microanalysis (EPMA) were found to proceed in the following order: Nb {yields} {alpha}-Nb(N) {yields} {beta}-Nb{sub 2}N{sub 1{+-}}{sub x} {yields} {gamma}-Nb{sub 4}N{sub 3{+-}}{sub x} {yields} {delta}-NbN{sub 1{+-}}{sub x}. The size of niobium particles which could react with nitrogen to yield cubic niobium nitride was estimated (SEM analysis) from the dependence of the thickness {delta} of the {delta}-NbN{sub 1{+-}}{sub x} outer layer formed on the surface of Nb particles on the dwell time t{sub dw} at 1460-1473 deg. C. It was shown that {delta} grew nearly proportional to t{sub dw}. At t{sub dw} = 30 min and P(N{sub 2}) = 2 MPa, {delta} was found to attain a value of about 15.5 {mu}m. Prolonged heating (t{sub dw} {approx} 60 min) was found to result in decomposition of the single-phase cubic niobium nitride into a two-phase (multiphase) product. This was confirmed by XRD data and magnetic measurements which showed the occurrence of two different critical temperatures T{sub c} in the same sample. The maximum critical temperature T{sub c} was found to attain a value of 15.6 K.

  9. Test Pile Reactivity Loss Due to Trichloroethylene

    SciTech Connect (OSTI)

    Plumlee, K.E.

    2001-03-09T23:59:59.000Z

    The presence of trichloroethylene in the test pile caused a continual decrease in pile reactivity. A system which removed, purified, and returned 12,000 cfh helium to the pile has held contamination to a negligible level and has permitted normal pile operation.

  10. Studies on Waterborne Pathogen Reactivation after Disinfection

    E-Print Network [OSTI]

    Kaur, Jasjeet

    2013-12-09T23:59:59.000Z

    ultraviolet (LP UV) irradiation at five titanium dioxide (TiO_(2)) concentrations (1 g/L, 0.5 g/L, 0.75 g/L, and 0.1 g/L) to achieve 5 log_(10) reduction of a laboratory E. coli K-12 strain (ATCC® 10798). Regrowth and reactivation of E. coli in dark and light...

  11. Controlling uranium reactivity March 18, 2008

    E-Print Network [OSTI]

    Meyer, Karsten

    for the last decade. Most of their work involves depleted uranium, a more common form of uraniumMarch 2008 Controlling uranium reactivity March 18, 2008 Uranium is an often misunderstood metal uranium research. In reality, uranium presents a wealth of possibilities for funda- mental chemistry. Many

  12. Assessment of the Economic Potential of Microgrids for Reactive Power Supply

    E-Print Network [OSTI]

    Appen, Jan von

    2012-01-01T23:59:59.000Z

    Reactive Power from Distributed Energy”, The Electricityvoltage. Electricity consumers’ demand for reactive power ison electricity supply security, the costs of local reactive

  13. Simultaneous MS-IR Studies of Surface Formate Reactivity Under...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    MS-IR Studies of Surface Formate Reactivity Under Methanol Synthesis Conditions on CuSiO2. Simultaneous MS-IR Studies of Surface Formate Reactivity Under Methanol Synthesis...

  14. Isotope effects in methanol synthesis and the reactivity of copper...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Isotope effects in methanol synthesis and the reactivity of copper formates on a CuSiO2 catalyst. Isotope effects in methanol synthesis and the reactivity of copper formates on a...

  15. Parallel Web Scripting with Reactive Constraints Thibaud Hottelier

    E-Print Network [OSTI]

    Bodik, Rastisla

    Parallel Web Scripting with Reactive Constraints Thibaud Hottelier James Ide Doug Kimelman Ras Bodik Electrical Engineering and Computer Sciences University of California at Berkeley Technical Report to lists, requires prior specific permission. #12;Parallel Web Scripting with Reactive Constraints Thibaud

  16. The effects of radient heat on pain reactivity 

    E-Print Network [OSTI]

    Kallina, Charles Frank

    1994-01-01T23:59:59.000Z

    Prior research has shown that an aversive event can produce either a decrease (hypoalgesia) or an increase in pain reactivity (hyperalgesia). The present study explores the impact of a suprathreshold exposure to radiant heat on pain reactivity. Rats...

  17. Reactive Dehydration technology for Production of Fuels and Chemicals...

    Broader source: Energy.gov (indexed) [DOE]

    platform (Intensified Catalytic and Reactive Distillation) for compact, inexpensive production of biomass-based chemicals from complex aqueous mixtures. Separation...

  18. Chemically Reactive Working Fluids for the Capture and Transport...

    Broader source: Energy.gov (indexed) [DOE]

    More Documents & Publications Planar Optical Waveguide Coupler Transformers for High-Power Solar Enegy Collection and Transmission Chemically Reactive Working...

  19. The Simulation of Synchronous Reactive Systems In Ptolemy II

    E-Print Network [OSTI]

    The Simulation of Synchronous Reactive Systems In Ptolemy II by Paul Whitaker Submitted to the Department of Electrical Engineering and Computer Sciences, University of California at Berkeley, in partial;_____________________________________________________________________ Simulation of Synchronous Reactive Systems in Ptolemy II ii Abstract The Synchronous Reactive (SR) domain

  20. Autonomic Reactive Systems via Online Learning Sanjit A. Seshia

    E-Print Network [OSTI]

    California at Irvine, University of

    Autonomic Reactive Systems via Online Learning Sanjit A. Seshia Department of Electrical@eecs.berkeley.edu Abstract-- Reactive systems are those that maintain an ongoing interaction with their environment- covering a class of reactive systems from run-time failures. This class of systems comprises those whose

  1. Towards Synthesis of Reactive & Robust Behavior Chains Amol D. Mali

    E-Print Network [OSTI]

    Mali, Amol D.

    Towards Synthesis of Reactive & Robust Behavior Chains Amol D. Mali Electrical Engg. & Computer robots need to be reactive and robust. Behavior-based robots that identify and repair the failures have of reactivity and robustness have been hitherto only informally used and have been loaded with var- ious

  2. A Synchronous Approach to Reactive System Design1 Charles Andr

    E-Print Network [OSTI]

    André, Charles

    our experience teaching discrete-event reactive systems to Electrical Engineering students. The courseA Synchronous Approach to Reactive System Design1 Charles André I3S Laboratory ­ UNSA/CNRS BP 121 This paper was presented at the 12th EAEEIE Annual Conf., 14-16 May 2001, Nancy (France). Abstract Reactive

  3. On Some Properties of Instantaneous Active and Reactive Powers

    E-Print Network [OSTI]

    Czarnecki, Leszek S.

    On Some Properties of Instantaneous Active and Reactive Powers Leszek S. CZARNECKI, Fellow IEEE Louisiana State University, USA Abstract: Some features of the instantaneous active and reactive powers p control. Also it was shown that the instantaneous reactive power q cannot be interpreted as a measure

  4. ENVIRONMENTAL REACTIVITY OF SOLID STATE HYDRIDE MATERIALS

    SciTech Connect (OSTI)

    Gray, J; Donald Anton, D

    2009-04-23T23:59:59.000Z

    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.

  5. Lattice-Boltzmann Simulations of Multiphase Flows in Gas-Diffusion-Layer (GDL) of a PEM Fuel Cell

    SciTech Connect (OSTI)

    Shiladitya Mukherjeea; J. Vernon Cole; Kunal Jainb; Ashok Gidwania

    2008-11-01T23:59:59.000Z

    Improved power density and freeze-thaw durability in automotive applications of Proton Exchange Membrane Fuel Cells (PEMFCs) requires effective water management at the membrane. This is controlled by a porous hydrophobic gas-diffusion-layer (GDL) inserted between the membrane catalyst layer and the gas reactant channels. The GDL distributes the incoming gaseous reactants on the catalyst surface and removes excess water by capillary action. There is, however, limited understanding of the multiphase, multi-component transport of liquid water, vapor and gaseous reactants within these porous materials. This is due primarily to the challenges of in-situ diagnostics for such thin (200 -? 300 {microns}), optically opaque (graphite) materials. Transport is typically analyzed by fitting Darcy's Law type expressions for permeability, in conjunction with capillary pressure relations based on formulations derived for media such as soils. Therefore, there is significant interest in developing predictive models for transport in GDLs and related porous media. Such models could be applied to analyze and optimize systems based on the interactions between cell design, materials, and operating conditions, and could also be applied to evaluating material design concepts. Recently, the Lattice Boltzmann Method (LBM) has emerged as an effective tool in modeling multiphase flows in general, and flows through porous media in particular. This method is based on the solution of a discrete form of the well-known Boltzmann Transport Equation (BTE) for molecular distribution, tailored to recover the continuum Navier-Stokes flow. The kinetic theory basis of the method allows simple implementation of molecular forces responsible for liquid-gas phase separation and capillary effects. The solution advances by a streaming and collision type algorithm that makes it suitable to implement for domains with complex boundaries. We have developed both single and multiphase LB models and applied them to simulate flow through porous GDL materials. We will present an overview of the methods as implemented, verification studies for both microstructure reconstruction and transport simulations, and application to single- and two-phase transport in GDL structures. The applications studies are designed to both improve understanding of transport within a given structure, and to investigate possible routes for improving material properties through microstructure design.

  6. Reactivity control assembly for nuclear reactor. [LMFBR

    DOE Patents [OSTI]

    Bollinger, L.R.

    1982-03-17T23:59:59.000Z

    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.

  7. Nuclear reactivity control using laser induced polarization

    DOE Patents [OSTI]

    Bowman, Charles D. (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    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.

  8. Nuclear reactivity control using laser induced polarization

    DOE Patents [OSTI]

    Bowman, Charles D. (Los Alamos, NM)

    1991-01-01T23:59:59.000Z

    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.

  9. Reactive Attachment Disorder: Concepts, Treatment, and Research

    E-Print Network [OSTI]

    Walter, Uta M.; Petr, Chris

    2004-06-01T23:59:59.000Z

    Best Practices in Children’s Mental Health: A Series of Reports Summarizing the Empirical Research on Selected Topics Report #11 “Reactive Attachment Disorder: Concepts, Treatment and Research” June, 2004... Healthcare” Report #8 – October 2003, “Best Practices in Therapeutic Foster Care: Review of the Literature and Local Practices in the State of Kansas” Report #9 – December 2003, “Juveniles with Sexual Offending Behaviors” Report #10-February 2004...

  10. Extraction of dihadron-jet correlations with rigorous flow-background subtraction in a multiphase transport model

    E-Print Network [OSTI]

    Yu-hui Zhu; Y. G. Ma; J. H. Chen; G. L. Ma; S. Zhang; C. Zhong

    2013-09-26T23:59:59.000Z

    Dihadron azimuthal correlations in Au+Au collisions at $\\sqrt{S_{NN}}$=200 GeV have been explored by using a multi-phase transport (AMPT) model. In order to obtain the contributions from jet-medium interactions, the combined harmonic flow background is subtracted from the raw dihadron correlation functions. The signals are compared in three associated transverse momentum ($p_{T}^{assoc}$) bins: 0.2-0.8 GeV/c, 0.8-1.4 GeV/c and 1.4-2.0 GeV/c from central to semi-peripheral geometries. The medium modifications are observed from changes in the signal shape and the relative jet contribution has been obtained within the change in the centrality from peripheral to central one. A strong $p_{T}^{assoc}$ dependence of the RMS width of jet correlation function is observed within the central geometry bin, i.e. 0-10$%$.

  11. Device and method for measuring multi-phase fluid flow in a conduit having an abrupt gradual bend

    DOE Patents [OSTI]

    Ortiz, M.G.

    1998-02-10T23:59:59.000Z

    A system is described for measuring fluid flow in a conduit having an abrupt bend. The system includes pressure transducers, one disposed in the conduit at the inside of the bend and one or more disposed in the conduit at the outside of the bend but spaced a distance therefrom. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.

  12. Numerical simulation of the non-isothermal developing flow of a nonlinear viscoelastic fluid in a rectangular channel

    E-Print Network [OSTI]

    Nikoleris, Teo

    1988-01-01T23:59:59.000Z

    Fluid in a Rectangular Channel (December 1988) Teo Nikoleris, B. S. , Reed College Chairman of Advisory Committee: Dr. R. Darby An orthogonal collocation finite element program was used to numerically model the hydrodynamicslly and thermally... in negligible increase of Nw~ ~?. Also, the approach of Chang and Finlayson [6], [7] who applied orthogonal collocation finite elements in conjunction with bicubic Hermitian polynomials to approximate various viscoelastic flow problems, also met with little...

  13. A reduced-order model based on proper orthogonal decomposition for non-isothermal two-phase flows

    E-Print Network [OSTI]

    Richardson, Brian Ross

    2009-05-15T23:59:59.000Z

    of computational costs. v NOMENCLATURE Cp ? Constant pressure speciflc heat dps ? Solid particle diameter Fgs ? Coe?cient for the interphase force between gas and solid phases g ? Gravity acceleration K ? Difiusivity coe?cient m ? Number of POD modes M ? Number... for the POD-based reduced-order mod- els. The conclusions and future work are presented in Chapter VIII. Appendix A describes the constitutive models used to close the transport equations. Appendix B presents the algorithm for calculating the convection...

  14. Non-isothermal flow in low permeable porous media: A comparison of Richards' and two-phase flow approaches

    E-Print Network [OSTI]

    Wang, W.

    2010-01-01T23:59:59.000Z

    the near ?eld of heat emitting waste deposited in geologicalthe heat source condition of the nuclear waste canister. The

  15. Non-isothermal flow in low permeable porous media: A comparison of Richards' and two-phase flow approaches

    E-Print Network [OSTI]

    Wang, W.

    2010-01-01T23:59:59.000Z

    density Speci?c heat capacity of liquid phase Speci?c heatspeci?c heat capacity of the solid phase, the liquid phase,Heat capacity Heat conductivity Intrinsic permeability of liquid

  16. A practical method for estimating non-isothermal and formation damage skin factors for cold water injection wells

    E-Print Network [OSTI]

    Warland, Arild

    1986-01-01T23:59:59.000Z

    0. 3 0. 3 0. 3 0. 3 1. 0 1. 0 1. 0 1. 0 1. 9 1. 9 1. 9 1. 9 1. 9 60 60 60 60 60 60 60 60 60 460 60 60 60 Iso Iso Non-Iso Non-Iso Iso Iso Non-Iso Non-Iso Iso Iso Non-Iso Iso Non;Iso 200 200 80 80 200 200 80... 80 200 200 80 200 80 yes yes yes yes yes yes 28 TABLE 3 (Continued) Run No. Conditions Case t& (day ) Th 1*fee t T& ('E) s mech 14 2 0. 3 100 Iso 167 15 16 17 18 19 20 21 22 23 24 25 26 27 28 2 0. 3 2 0. 3 2 0. 3 2 0...

  17. A single-phase, non-isothermal model for PEM fuel cells Hyunchul Ju, Hua Meng, Chao-Yang Wang *

    E-Print Network [OSTI]

    a similar amount of waste heat to its electric power output, and tolerates a small temperature deviation membrane fuel cell (PEMFC) produces nearly a similar amount of waste heat to its electric power output so

  18. Experimental determination of the speciation, partitioning, and release of perrhenate as a chemical surrogate for pertechnetate from a sodalite-bearing multiphase ceramic waste form

    SciTech Connect (OSTI)

    Pierce, Eric M.; Lukens, Wayne W.; Fitts, Jeff. P.; Jantzen, Carol. M.; Tang, G.

    2013-12-01T23:59:59.000Z

    A key component to closing the nuclear fuel cycle is the storage and disposition of nuclear waste in geologic systems. Multiphase ceramic waste forms have been studied extensively as a potential host matrix for nuclear waste. Understanding the speciation, partitioning, and release behavior of radionuclides immobilized in multiphase ceramic waste forms is a critical aspect of developing the scientific and technical basis for nuclear waste management. In this study, we evaluated a sodalite-bearing multiphase ceramic waste form (i.e., fluidized-bed steam reform sodium aluminosilicate [FBSR NAS] product) as a potential host matrix for long-lived radionuclides, such as technetium (99Tc). The FBSR NAS material consists primarily of nepheline (ideally NaAlSiO4), anion-bearing sodalites (ideally M8[Al6Si6O24]X2, where M refers to alkali and alkaline earth cations and X refers to monovalent anions), and nosean (ideally Na8[AlSiO4]6SO4). Bulk X-ray absorption fine structure analysis of the multiphase ceramic waste form, suggest rhenium (Re) is in the Re(VII) oxidation state and has partitioned to a Re-bearing sodalite phase (most likely a perrhenate sodalite Na8[Al6Si6O24](ReO4)2). Rhenium was added as a chemical surrogate for 99Tc during the FBSR NAS synthesis process. The weathering behavior of the FBSR NAS material was evaluated under hydraulically unsaturated conditions with deionized water at 90 ?C. The steady-state Al, Na, and Si concentrations suggests the weathering mechanisms are consistent with what has been observed for other aluminosilicate minerals and include a combination of ion exchange, network hydrolysis, and the formation of an enriched-silica surface layer or phase. The steady-state S and Re concentrations are within an order of magnitude of the nosean and perrhenate sodalite solubility, respectively. The order of magnitude difference between the observed and predicted concentration for Re and S may be associated with the fact that the anion-bearing sodalites contained in the multiphase ceramic matrix are present as mixed-anion sodalite phases. These results suggest the multiphase FBSR NAS material may be a viable host matrix for long-lived, highly mobilie radionuclides which is a critical aspect in the management of nuclear waste.

  19. Experimental Determination of the Speciation, Partitioning, and Release of Perrhenate as a Chemical Surrogate for Pertechnetate from a Sodalite-Bearing Multiphase Ceramic Waste Form

    SciTech Connect (OSTI)

    Pierce, Eric M [ORNL] [ORNL; Lukens, Wayne W [Lawrence Berkeley National Laboratory (LBNL)] [Lawrence Berkeley National Laboratory (LBNL); Fitts, Jeffrey P [Princeton University] [Princeton University; Tang, Guoping [ORNL] [ORNL; Jantzen, C M [Savannah River National Laboratory (SRNL)] [Savannah River National Laboratory (SRNL)

    2013-01-01T23:59:59.000Z

    A key component to closing the nuclear fuel cycle is the storage and disposition of nuclear waste in geologic systems. Multiphase ceramic waste forms have been studied extensively as a potential host matrix for nuclear waste. Understanding the speciation, partitioning, and release behavior of radionuclides immobilized in multiphase ceramic waste forms is a critical aspect of developing the scientific and technical basis for nuclear waste management. In this study, we evaluated a sodalite-bearing multiphase ceramic waste form (i.e., fluidized-bed steam reform sodium aluminosilicate [FBSR NAS] product) as a potential host matrix for long-lived radionuclides, such as technetium (99Tc). The FBSR NAS material consists primarily of nepheline (ideally NaAlSiO4), anion-bearing sodalites (ideally M8[Al6Si6O24]X2, where M refers to alkali and alkaline earth cations and X refers to monovalent anions), and nosean (ideally Na8[AlSiO4]6SO4). Bulk x-ray absorption fine structure analysis of the multiphase ceramic waste form, suggest rhenium (Re) is in the Re(VII) oxidation state and has partitioned to a Re-bearing sodalite phase (most likely a perrhenate sodalite Na8[Al6Si6O24](ReO4)2). Rhenium was added as a chemical surrogate for 99Tc during the FBSR NAS synthesis process. The weathering behavior of the FBSR NAS material was evaluated under hydraulically unsaturated conditions with deionized water at 90 C. The steady-state Al, Na, and Si concentrations suggests the weathering mechanisms are consistent with what has been observed for other aluminosilicate minerals and include a combination of ion exchange, network hydrolysis, and the formation of an enriched-silica surface layer or phase. The steady-state S and Re concentrations are within an order of magnitude of the nosean and perrhenate sodalite solubility, respectively. The order of magnitude difference between the observed and predicted concentration for Re and S may be associated with the fact that the anion-bearing sodalites contained in the multiphase ceramic matrix are present as mixed-anion sodalite phases. These results suggest the multiphase FBSR NAS material may be a viable host matrix for long-lived, highly mobilie radionuclides which is a critical aspect in the management of nuclear waste.

  20. A novel reactive processing technique: using telechelic polymers to reactively compatibilize polymer blends

    SciTech Connect (OSTI)

    Ashcraft, Earl C [ORNL; Ji, Haining [ORNL; Mays, Jimmy [ORNL; Dadmun, Mark D [ORNL

    2009-01-01T23:59:59.000Z

    Difunctional reactive polymers, telechelics, were used to reactively form multiblock copolymers in situ when melt-blended with a blend of polystyrene and polyisoprene. To quantify the ability of the copolymer to compatibilize the blends, the time evolution of the domain size upon annealing was analyzed by SEM. It was found that the most effective parameter to quantify the ability of the copolymer to inhibit droplet coalescence is Kreltstable, the relative coarsening constant multiplied by the stabilization time. These results indicate that intermediate-molecular-weight telechelic pairs of both highly reactive Anhydride-PS-Anhydride/NH2-PI-NH2 and slower reacting Epoxy-PS-Epoxy/COOH-PI-COOH both effectively suppress coalescence, with the optimal molecular weight being slightly above the critical molecular weight of the homopolymer,Mc. The effects of telechelic loading were also investigated, where the optimal loading concentration for this system was 0.5 wt %, as higher concentrations exhibited a plasticizing effect due to the presence of unreacted low-molecular-weight telechelics present in the blend. A determination of the interfacial coverage of the copolymer shows that a conversion of 1.5-3.0% was required for 20% surface coverage at 5.0 wt % telechelic loading, indicating a large excess of telechelics in this system. At the optimal loading level of 0.5 wt %, a conversion of 15% was required for 20% surface coverage. The results of these experiments provide a clear understanding of the role of telechelic loading and molecular weight on its ability to reactively form interfacial modifiers in phase-separated polymer blends and provide guidelines for the development of similar reactive processing schemes that can use telechelic polymers to reactively compatibilize a broad range of polymer blends.

  1. The effects of gas-fluid-rock interactions on CO2 injection and storage: Insights from reactive transport modeling

    SciTech Connect (OSTI)

    Xiao, Y.; Xu, T.; Pruess, K.

    2008-10-15T23:59:59.000Z

    Possible means of reducing atmospheric CO{sub 2} emissions include injecting CO{sub 2} in petroleum reservoirs for Enhanced Oil Recovery or storing CO{sub 2} in deep saline aquifers. Large-scale injection of CO{sub 2} into subsurface reservoirs would induce a complex interplay of multiphase flow, capillary trapping, dissolution, diffusion, convection, and chemical reactions that may have significant impacts on both short-term injection performance and long-term fate of CO{sub 2} storage. Reactive Transport Modeling is a promising approach that can be used to predict the spatial and temporal evolution of injected CO{sub 2} and associated gas-fluid-rock interactions. This presentation will summarize recent advances in reactive transport modeling of CO{sub 2} storage and review key technical issues on (1) the short- and long-term behavior of injected CO{sub 2} in geological formations; (2) the role of reservoir mineral heterogeneity on injection performance and storage security; (3) the effect of gas mixtures (e.g., H{sub 2}S and SO{sub 2}) on CO{sub 2} storage; and (4) the physical and chemical processes during potential leakage of CO{sub 2} from the primary storage reservoir. Simulation results suggest that CO{sub 2} trapping capacity, rate, and impact on reservoir rocks depend on primary mineral composition and injecting gas mixtures. For example, models predict that the injection of CO{sub 2} alone or co-injection with H{sub 2}S in both sandstone and carbonate reservoirs lead to acidified zones and mineral dissolution adjacent to the injection well, and carbonate precipitation and mineral trapping away from the well. Co-injection of CO{sub 2} with H{sub 2}S and in particular with SO{sub 2} causes greater formation alteration and complex sulfur mineral (alunite, anhydrite, and pyrite) trapping, sometimes at a much faster rate than previously thought. The results from Reactive Transport Modeling provide valuable insights for analyzing and assessing the dynamic behaviors of injected CO{sub 2}, identifying and characterizing potential storage sites, and managing injection performance and reducing costs.

  2. Relative reactivities of solid benzoic acids

    E-Print Network [OSTI]

    Warwas, Edwin James

    1967-01-01T23:59:59.000Z

    REACTIVITIES OF SOLID BENZOIC ACIDS (January 1967) Edwin James Warwas B. S. , Southwest Texas State College Directed by: Dr. C. K. Hancock and Dr. E. A. Meyers The reactions of solid benzoic acid (BZAH) and nine m- or p- substituted benzoic acids (RBZAH...) with solid potassium benzoate (BZAK) and m- or p-substituted potassium benzoates (R'BZAK) have been carried out in sealed thin-walled glass capillary tubes or in 0 sealed weighing bottles at 70 For the reaction, RBZAH + R'BZAK, where R = R', the product...

  3. Preparation of reactive beta-dicalcium silicate

    DOE Patents [OSTI]

    Shen, Ming-Shing (Laramie, WY, NJ); Chen, James M. (Rahway, NJ); Yang, Ralph T. (Amherst, NY)

    1982-01-01T23:59:59.000Z

    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.

  4. Preparation of reactive beta-dicalcium silicate

    DOE Patents [OSTI]

    Shen, M.S.; Chen, J.M.; Yang, R.T.

    1980-02-28T23:59:59.000Z

    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.

  5. Reactive sticking coefficients of silane on silicon

    SciTech Connect (OSTI)

    Buss, R.J.; Ho, P.; Breiland, W.G.; Coltrin, M.E.

    1988-09-15T23:59:59.000Z

    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.

  6. T2WELL/ECO2N

    Energy Science and Technology Software Center (OSTI)

    002966IBMPC00 T2Well/ECO2N Version 1.0: Multiphase and Non-Isothermal Model for Coupled Wellbore-Reservoir Flow of Carbon Dioxide and Variable Salinity Water  http:..esd.lbl.gov/tough/licensing.html 

  7. Reactive power planning of large-scale systems

    SciTech Connect (OSTI)

    Burchett, R.C.; Happ, H.H.; Vierath, D.R.

    1983-01-01T23:59:59.000Z

    This paper discusses short-term operations planning applications in reactive power management involving existing equipment. Reactive power planning involves the sizing and siting of additional reactive support equipment in order to satisfy system voltage constraints (minimum and maximum limits) under both normal and contingency conditions. The use of the Optimal Power Flow (OPF) and the VARPLAN computer codes for operations planning are examined. The OPF software can be used to determine if reactive outputs from nearby generators are scheduled properly, and to confirm that parallel transformers have been properly set. A major benefit of the system planning software VARPLAN is the ability to simultaneously consider both normal and contingency conditions, while adding a minimal amount of new reactive power. Applications to long-term system planning of new reactive power sources are described.

  8. Three-dimensional multiphase segmentation of X-ray CT data of porous materials using a Bayesian Markov random field framework

    SciTech Connect (OSTI)

    Kulkarni, Ramaprasad; Tuller, Markus; Fink, Wolfgang; Wildschild, Dorthe (Oregon State U.); (Ariz)

    2012-07-27T23:59:59.000Z

    Advancements in noninvasive imaging methods such as X-ray computed tomography (CT) have led to a recent surge of applications in porous media research with objectives ranging from theoretical aspects of pore-scale fluid and interfacial dynamics to practical applications such as enhanced oil recovery and advanced contaminant remediation. While substantial efforts and resources have been devoted to advance CT technology, microscale analysis, and fluid dynamics simulations, the development of efficient and stable three-dimensional multiphase image segmentation methods applicable to large data sets is lacking. To eliminate the need for wet-dry or dual-energy scans, image alignment, and subtraction analysis, commonly applied in X-ray micro-CT, a segmentation method based on a Bayesian Markov random field (MRF) framework amenable to true three-dimensional multiphase processing was developed and evaluated. Furthermore, several heuristic and deterministic combinatorial optimization schemes required to solve the labeling problem of the MRF image model were implemented and tested for computational efficiency and their impact on segmentation results. Test results for three grayscale data sets consisting of dry glass beads, partially saturated glass beads, and partially saturated crushed tuff obtained with synchrotron X-ray micro-CT demonstrate great potential of the MRF image model for three-dimensional multiphase segmentation. While our results are promising and the developed algorithm is stable and computationally more efficient than other commonly applied porous media segmentation models, further potential improvements exist for fully automated operation.

  9. INVESTIGATION OF MULTISCALE AND MULTIPHASE FLOW, TRANSPORT AND REACTION IN HEAVY OIL RECOVERY PROCESSES

    SciTech Connect (OSTI)

    Yannis C. Yortsos

    2003-02-01T23:59:59.000Z

    This is final report for contract DE-AC26-99BC15211. The report describes progress made in the various thrust areas of the project, which include internal drives for oil recovery, vapor-liquid flows, combustion and reaction processes and the flow of fluids with yield stress. The report consists mainly of a compilation of various topical reports, technical papers and research reports published produced during the three-year project, which ended on May 6, 2002 and was no-cost extended to January 5, 2003. Advances in multiple processes and at various scales are described. In the area of internal drives, significant research accomplishments were made in the modeling of gas-phase growth driven by mass transfer, as in solution-gas drive, and by heat transfer, as in internal steam drives. In the area of vapor-liquid flows, we studied various aspects of concurrent and countercurrent flows, including stability analyses of vapor-liquid counterflow, and the development of novel methods for the pore-network modeling of the mobilization of trapped phases and liquid-vapor phase changes. In the area of combustion, we developed new methods for the modeling of these processes at the continuum and pore-network scales. These models allow us to understand a number of important aspects of in-situ combustion, including steady-state front propagation, multiple steady-states, effects of heterogeneity and modes of combustion (forward or reverse). Additional aspects of reactive transport in porous media were also studied. Finally, significant advances were made in the flow and displacement of non-Newtonian fluids with Bingham plastic rheology, which is characteristic of various heavy oil processes. Various accomplishments in generic displacements in porous media and corresponding effects of reservoir heterogeneity are also cited.

  10. Analyzing the status of oxide surface photochemical reactivity...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    photochemical reactivity Released: July 28, 2013 Invited review shows power of scanning tunneling microscopy to understand and control the surface photochemistry of oxide...

  11. advanced reactivity measurement: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Alfredo) 2011-01-01 302 High Purity Ethyl Acetate Production with a Batch Reactive Distillation Column using Dynamic Optimization Strategy CiteSeer Summary: AbstractEthyl...

  12. advanced reactivity measurement facility-1: Topics by E-print...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Alfredo) 2011-01-01 306 High Purity Ethyl Acetate Production with a Batch Reactive Distillation Column using Dynamic Optimization Strategy CiteSeer Summary: AbstractEthyl...

  13. Airborne measurement of OH reactivity during INTEX-B

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    plus OH sign), reactiv- propane ing different gases gases atisoprene (plus sign), propane (star) and propene (triangle).NMHC includes ethane, ethene, propane, propene, i-butane, n-

  14. Optimization Online - Reactive Power Management using Firefly and ...

    E-Print Network [OSTI]

    Ripunjoy Phukan

    2013-10-04T23:59:59.000Z

    Oct 4, 2013 ... Reactive Power Management using Firefly and Spiral Optimization under Static and Dynamic Loading Conditions. Ripunjoy Phukan (ripun000 ...

  15. Advancing Reactive Tracer Methods for Measuring Thermal Evolution...

    Open Energy Info (EERE)

    Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2- and Water-Based Geothermal Reservoirs Geothermal Lab Call Project Jump to: navigation, search Last...

  16. Quantitative Site-specific Reactivity Profiling of S-Nitrosylation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Profiling of S-Nitrosylation in Mouse Skeletal Muscle Using Cysteinyl Peptide Enrichment Quantitative Site-specific Reactivity Profiling of S-Nitrosylation in Mouse Skeletal...

  17. Ground rubber: Reactive permeable barrier sorption media

    SciTech Connect (OSTI)

    Kershaw, D.S.; Pamukcu, S. [Lehigh Univ., Bethlehem, PA (United States)

    1997-12-31T23:59:59.000Z

    The objective of this research was to examine the feasibility of using ground tire rubber as a sorbent media in reactive permeable barrier systems. Previous research by the current authors has demonstrated that tire rubber can sorb significant quantities of benzene, toluene, ethylbenzene and O-xylene from aqueous solutions. The current research was run to examine the usage rate of ground rubber in a packed bed reactor under specific contact times. In addition, desorption and repetitive sorption tests were run to determine the reversibility of the sorption process for ground tire rubber. These tests were run to determine the regeneration capacity of ground tire rubber. Results of the study show that the usage rates are greater than 50% with an empty bed contact times of 37 minutes, and minimal amounts of energy are needed to regenerate the tire rubber after use.

  18. Pb-Pb collisions at $\\sqrt{s_{NN}}=2.76$ TeV in a multiphase transport model

    E-Print Network [OSTI]

    Jun Xu; Che Ming Ko

    2011-02-14T23:59:59.000Z

    The multiplicity and elliptic flow of charged particles produced in Pb-Pb collisions at center of mass energy $\\sqrt{s_{NN}}=2.76$ TeV from the Large Hadron Collider are studied in a multiphase transport (AMPT) model. With the standard parameters in the HIJING model, which is used as initial conditions for subsequent partonic and hadronic scatterings in the AMPT model, the resulting multiplicity of final charged particles at mid-pseudorapidity is consistent with the experimental data measured by the ALICE Collaboration. This value is, however, increased by about 25% if the final-state partonic and hadronic scatterings are turned off. Because of final-state scatterings, particular those among partons, the final elliptic flow of charged hadrons is also consistent with the ALICE data if a smaller but more isotropic parton scattering cross section than previously used in the AMPT model for describing the charged hadron elliptic flow in heavy ion collisions at the Relativistic Heavy Ion Collider is used. The resulting transverse momentum spectra of charged particles as well as the centrality dependence of their multiplicity density and the elliptic flow are also in reasonable agreement with the ALICE data. Furthermore, the multiplicities, transverse momentum spectra and elliptic flows of identified hadrons such as protons, kaons and pions are predicted.

  19. Dual FIB-SEM 3D imaging and lattice boltzmann modeling of porosimetry and multiphase flow in chalk.

    SciTech Connect (OSTI)

    Rinehart, Alex; Petrusak, Robin (Advanced Resources International, Inc., Arlington, VA); Heath, Jason E.; Dewers, Thomas A.; Yoon, Hongkyu

    2010-12-01T23:59:59.000Z

    Mercury intrusion porosimetry (MIP) is an often-applied technique for determining pore throat distributions and seal analysis of fine-grained rocks. Due to closure effects, potential pore collapse, and complex pore network topologies, MIP data interpretation can be ambiguous, and often biased toward smaller pores in the distribution. We apply 3D imaging techniques and lattice-Boltzmann modeling in interpreting MIP data for samples of the Cretaceous Selma Group Chalk. In the Mississippi Interior Salt Basin, the Selma Chalk is the apparent seal for oil and gas fields in the underlying Eutaw Fm., and, where unfractured, the Selma Chalk is one of the regional-scale seals identified by the Southeast Regional Carbon Sequestration Partnership for CO2 injection sites. Dual focused ion - scanning electron beam and laser scanning confocal microscopy methods are used for 3D imaging of nanometer-to-micron scale microcrack and pore distributions in the Selma Chalk. A combination of image analysis software is used to obtain geometric pore body and throat distributions and other topological properties, which are compared to MIP results. 3D data sets of pore-microfracture networks are used in Lattice Boltzmann simulations of drainage (wetting fluid displaced by non-wetting fluid via the Shan-Chen algorithm), which in turn are used to model MIP procedures. Results are used in interpreting MIP results, understanding microfracture-matrix interaction during multiphase flow, and seal analysis for underground CO2 storage.

  20. Modeling of multiphase flow in permeable media: (1) Mathematical model; (2) Analysis of imbibition and drying experiments

    SciTech Connect (OSTI)

    Bixler, N.E.; Eaton, R.R.

    1986-12-31T23:59:59.000Z

    Calculating multiphase flow of water through fractured porous media, such as volcanic tuff, is a numerically challenging problem because of the highly nonlinear material characteristics of permeability and saturation which describe liquid and gas transport. Typically, the permeability of the fractured host rock being investigated for an underground nuclear waste repository at Yucca Mountain, Nevada increases by 15 orders of magnitude as the rock becomes saturated. Furthermore, permeability may vary by five orders of magnitude between geologic strata. Other nonlinear mechanisms - Knudsen diffusion, binary diffusion, vapor pressure lowering, and adsorption of vapor onto pore walls - may also strongly affect liquid and gas transport. In Part I of the presentation, the mathematical model and its computer implementation are presented. The application of these equations and solution procedures to problems related to underground waste repositories are addressed in Part II. Predicted results will be compared with the results of laboratory experiments in which a core of volcanic tuff has first undergone controlled imbibition, then drying. The importance of the various transport mechanisms is demonstrated by examining the predicted results. 14 figs.

  1. Completing the complex Poynting theorem: Conservation of reactive energy in reactive time

    E-Print Network [OSTI]

    Gerald Kaiser

    2014-12-11T23:59:59.000Z

    The complex Poynting theorem is extended canonically to a time-scale domain $(t, s)$ by replacing the phasors of time-harmonic fields by the analytic signals $X(r, t+is)$ of fields $X(r,t)$ with general time dependence. The imaginary time $s>0$ is shown to play the role of a time resolution scale, and the extended Poynting theorem splits into two conservation laws: its real part gives the conservation in $t$ of the scale-averaged active energy at fixed $s$, and its imaginary part gives the conservation in $s$ of the scale-averaged reactive energy at fixed $t$. At coarse scales (large $s$, slow time), where the system reduces to the circuit level, this may have applications to the theory of electric power transmission and conditioning. At fine scales (small $s$, fast time) it describes reactive energy dynamics in radiating systems.

  2. ALUMINOSILICATE-COATED SILICA SAND FOR REACTIVE TRANSPORT EXPERIMENTS

    E-Print Network [OSTI]

    Flury, Markus

    ALUMINOSILICATE-COATED SILICA SAND FOR REACTIVE TRANSPORT EXPERIMENTS By JORGE ANTONIO JEREZ transport experiments; Dr. Barbara Williams and Jason Shira from University of Idaho for providing access-COATED SILICA SAND FOR REACTIVE TRANSPORT EXPERIMENTS Abstract by Jorge Antonio Jerez Briones, Ph.D. Washington

  3. Assessment of sequence homology and cross-reactivity

    SciTech Connect (OSTI)

    Aalberse, Rob C. [Department of Immunopathology, Sanquin Research at CLB, Plesmanlaan 125, 1066 CX Amsterdam (Netherlands) and Landsteiner Laboratory, Academic Medical Centre, 1066 CX Amsterdam (Netherlands)]. E-mail: r.aalberse@sanquin.nl

    2005-09-01T23:59:59.000Z

    Three aspects of allergenicity assessment and are discussed: IgE immunogenicity, IgE cross-reactivity and T cell cross-reactivity, all with emphasis on in-silico predictability: from amino acid sequence via 3D structure to allergenicity.(1)IgE immunogenicity depends to an overwhelming degree on factors other than the protein itself: the context and history of the protein by the time it reaches the immune system. Without specification of these two factors very few foreign proteins can be claimed to be absolutely non-allergenic. Any antigen may be allergenic, particularly if it avoids activation of TH2-suppressive mechanisms (CD8 cells, TH1 cells, other regulatory T cells and regulatory cytokines). (2)IgE cross-reactivity can be much more reliably assessed by a combination of in-silico homology searches and in vitro IgE antibody assays. The in-silico homology search is unlikely to miss potential cross-reactivity with sequenced allergens. So far, no biologically relevant cross-reactivity at the antibody level has been demonstrated between proteins without easily-demonstrable homology. (3)T cell cross-reactivity is much more difficult to predict compared to B cell cross-reactivity, and its effects are more diverse. Yet, pre-existing cross-reactive T cell activity is likely to influence the outcome not only of the immune response, but also of the effector phase of the allergic reaction.

  4. SHUSH: Reactive Transmit Power Control For Wireless MAC Protocols

    E-Print Network [OSTI]

    Han, Richard Y.

    SHUSH: Reactive Transmit Power Control For Wireless MAC Protocols Anmol Sheth and Richard Han@cs.colorado.edu Abstract-- Asymmetric transmission ranges caused due to transmit power control have the undesirable effect access. In this paper we present a new reactive power controlled MAC protocol, SHUSH, which tackles

  5. Multispecies Reactive Tracer Test in a Sand and

    E-Print Network [OSTI]

    Multispecies Reactive Tracer Test in a Sand and Gravel Aquifer, Cape Cod, Massachusetts United;Multispecies Reactive Tracer Test in a Sand and Gravel Aquifer, Cape Cod, Massachusetts Part 2 Transport- effectiveness for prevention and control of pollution to air, land, water, and subsurface resources; protection

  6. The Specification and Execution of Heterogeneous Synchronous Reactive Systems

    E-Print Network [OSTI]

    The Specification and Execution of Heterogeneous Synchronous Reactive Systems by Stephen Anthony in Engineering---Electrical Engineering and Computer Sciences in the GRADUATE DIVISION of the UNIVERSITY of Heterogeneous Synchronous Reactive Systems Copyright ã 1997 by Stephen Anthony Edwards #12; Abstract

  7. A Modified Reactive Control Framework for Cooperative Mobile Robots

    E-Print Network [OSTI]

    A Modified Reactive Control Framework for Cooperative Mobile Robots J. Salido a , J.M. Dolan a , J Dept. of Electrical & Computer Engineering, Carnegie Mellon Univ. Pittsburgh, PA 15213­3890 USA. Purely reactive approaches such as that of Brooks are efficient, but lack a mechanism for global control

  8. Reactive Sputtering of Bismuth Vanadate Photoanodes for Solar Water Splitting

    E-Print Network [OSTI]

    Javey, Ali

    Reactive Sputtering of Bismuth Vanadate Photoanodes for Solar Water Splitting Le Chen,, Esther of Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, California 94720 has remained relatively underexplored. Here, we report the synthesis of BiVO4 thin films by reactive

  9. Reactive Rearrangement of Parts under Sensor Inaccuracy: Particle Filter Approach

    E-Print Network [OSTI]

    Reactive Rearrangement of Parts under Sensor Inaccuracy: Particle Filter Approach Hal^uk Bayram, Electrical and Electronic Engineering Bogazici University, Bebek 34342 Istanbul Turkey Abstract-- The paper will be left undisturbed, the robot is required to employ a reactive strategy. A feedback-based event

  10. Reactive oxygen species deglycosilate glomerular a-dystroglycan

    E-Print Network [OSTI]

    Campbell, Kevin P.

    Reactive oxygen species deglycosilate glomerular a-dystroglycan NPJ Vogtla¨nder1 , WPM Tamboer1 open. Reactive oxygen species (ROS) are known to degrade and depolymerize carbohydrates, and to playDa in skeletal muscle, ranging from 120 kDa in brain to 190 kDa in the Torpedo electric organ.8

  11. Towards Interactive Timing Analysis for Designing Reactive Systems

    E-Print Network [OSTI]

    Towards Interactive Timing Analysis for Designing Reactive Systems Insa Fuhrmann David Broman Steven Smyth Reinhard von Hanxleden Electrical Engineering and Computer Sciences University of California Interactive Timing Analysis for Designing Reactive Systems Insa Fuhrmann1 , David Broman2,3 , Steven Smyth1

  12. Reactive ion etched substrates and methods of making and using

    DOE Patents [OSTI]

    Rucker, Victor C. (San Francisco, CA); Shediac, Rene (Oakland, CA); Simmons, Blake A. (San Francisco, CA); Havenstrite, Karen L. (New York, NY)

    2007-08-07T23:59:59.000Z

    Disclosed herein are substrates comprising reactive ion etched surfaces and specific binding agents immobilized thereon. The substrates may be used in methods and devices for assaying or isolating analytes in a sample. Also disclosed are methods of making the reactive ion etched surfaces.

  13. A REACTIVE APPROACH FOR MINING PROJECT EVALUATION UNDER PRICE UNCERTAINTY

    E-Print Network [OSTI]

    Duffy, Ken

    A REACTIVE APPROACH FOR MINING PROJECT EVALUATION UNDER PRICE UNCERTAINTY Meimei Zhang. This method often undervalues a mining project since it ignores future price uncertainty and does not allow on metal price. This paper also demonstrates that the "reactive" approach can estimate the mine project

  14. CLASSIFICATION AND REACTIVITY OF SECONDARY ALUMINUM PRODUCTION WASTE

    E-Print Network [OSTI]

    environment.14 Keywords: Landfills, aluminum, hydrogen, salt cake, dross, calorimeter, waste disposal15 16 17CLASSIFICATION AND REACTIVITY OF SECONDARY ALUMINUM PRODUCTION WASTE Navid H. Jafari Student Member and Reactivity of Secondary Aluminum Production Waste1 Navid H. Jafari1 , Timothy D. Stark2 and Ralph Roper3 2 3

  15. Biodiesel Fuel Property Effects on Particulate Matter Reactivity

    SciTech Connect (OSTI)

    Williams, A.; Black, S.; McCormick, R. L.

    2010-06-01T23:59:59.000Z

    Controlling diesel particulate emissions to meet the 2007 U.S. standard requires the use of a diesel particulate filter (DPF). The reactivity of soot, or the carbon fraction of particulate matter, in the DPF and the kinetics of soot oxidation are important in achieving better control of aftertreatment devices. Studies showed that biodiesel in the fuel can increase soot reactivity. This study therefore investigated which biodiesel fuel properties impact reactivity. Three fuel properties of interest included fuel oxygen content and functionality, fuel aromatic content, and the presence of alkali metals. To determine fuel effects on soot reactivity, the performance of a catalyzed DPF was measured with different test fuels through engine testing and thermo-gravimetric analysis. Results showed no dependence on the aromatic content or the presence of alkali metals in the fuel. The presence and form of fuel oxygen was the dominant contributor to faster DPF regeneration times and soot reactivity.

  16. Early maturation processes in coal. Part 2: Reactive dynamics simulations using the ReaxFF reactive force field on Morwell Brown coal structures

    E-Print Network [OSTI]

    Goddard III, William A.

    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

  17. Synthesis, characterization, and reactivity studies of iridium complexes bearing the ligand diphenylphosphidoboratabenzene

    E-Print Network [OSTI]

    Arizpe, Luis (Luis Alfredo)

    2011-01-01T23:59:59.000Z

    The synthesis, structure, and reactivity properties of three iridium square planar complexes bearing the anionic phosphine ligand diphenylphosphidoboratabenzene (DPB) are described. Reactivity studies show a rate enhancement ...

  18. Reactivity of iron-bearing minerals and CO2 sequestration: A...

    Office of Scientific and Technical Information (OSTI)

    Reactivity of iron-bearing minerals and CO2 sequestration: A multi-disciplinary experimental approach Re-direct Destination: The reactivity of sandstones was studied under...

  19. Aging Enhances the Production of Reactive Oxygen Species andBactericid...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Enhances the Production of Reactive Oxygen Species andBactericidal Activity in Peritoneal Macrophages by Aging Enhances the Production of Reactive Oxygen Species andBactericidal...

  20. Metal-Pyrrolide Complexes in Three-fold Symmetry: Synthesis, Structure, Reactivity and Magnetism

    E-Print Network [OSTI]

    Harman, William Hill

    2010-01-01T23:59:59.000Z

    Structure, Reactivity and Magnetism by William Hill Harman AStructure, Reactivity and Magnetism by William Hill Harmanlost time. Dave taught me magnetism and what it takes to win

  1. Exact regularized point particle method for multi-phase flows in the two-way coupling regime

    E-Print Network [OSTI]

    P. Gualtieri; F. Picano; G. Sardina; C. M. Casciola

    2014-05-27T23:59:59.000Z

    Particulate flows have been largely studied under the simplifying assumptions of one-way coupling regime where the disperse phase do not react-back on the carrier fluid. In the context of turbulent flows, many non trivial phenomena such as small scales particles clustering or preferential spatial accumulation have been explained and understood. A more complete view of multiphase flows can be gained calling into play two-way coupling effects, i.e. by accounting for the inter-phase momentum exchange between the carrier and the suspended phase, certainly relevant at increasing mass loading. In such regime, partially investigated in the past by the so-called Particle In Cell (PIC) method, much is still to be learned about the dynamics of the disperse phase and the ensuing alteration of the carrier flow. In this paper we present a new methodology rigorously designed to capture the inter-phase momentum exchange for particles smaller than the smallest hydrodynamical scale, e.g. the Kolmogorov scale in a turbulent flow. In fact, the momentum coupling mechanism exploits the unsteady Stokes flow around a small rigid sphere where the transient disturbance produced by each particle is evaluated in a closed form. The particles are described as lumped, point masses which would lead to the appearance of singularities. A rigorous regularization procedure is conceived to extract the physically relevant interactions between particles and fluid which avoids any "ah hoc" assumption. The approach is suited for high efficiency implementation on massively parallel machines since the transient disturbance produced by the particles is strongly localized in space around the actual particle position. As will be shown, hundred thousands particles can therefore be handled at an affordable computational cost as demonstrated by a preliminary application to a particle laden turbulent shear flow.

  2. XMM-Newton View of the Multi-Phase Warm Absorber in Seyfert 1 Galaxy NGC985

    E-Print Network [OSTI]

    Yair Krongold; Elena Jimenez-Bailon; Maria Santos-Lleo; Fabrizio Nicastro; Martin Elvis; Nancy Brickhouse; Mercedes Andrade-Velazquez; Luc Binette; Smita Mathur

    2008-09-09T23:59:59.000Z

    We present an analysis of an XMM-Newton observation of the Seyfert 1 Galaxy NGC 985. The EPIC spectra present strong residuals to a single power-law model, indicating the presence of ionized absorbing gas and a soft excess. A broad-band fit to the EPIC and RGS spectra shows that the continuum can be well fit with a power-law and a blackbody component. The RGS can be modeled either with two or three absorption components. In the two absorber model the low-ionization one, accounts for the presence of the Fe M-shell unresolved transition array (Fe VII-XIII), and the high ionization component is required by the presence of several Fe L-shell transitions. The data suggest the presence of a third ionized component with higher ionization, so that the Fe L-shell absorption features are produced by two different components (one producing absorption by Fe XVII-XX, and the other absorption by Fe XX-XXII). However, the presence of the third absorbing component cannot be detected by means of an isolated absorption line in a significant way, so we consider this detection only as tentative. Interestingly, all ionization components have similar kinematics. In addition, whether two or three absorbers are considered, the components appear to be in pressure balance. These results give further support to the idea that warm absorbers in AGN consist of a two or three-phase medium. We note that, while in the model with only two absorbers one of them (the high ionization component) lies on an unstable branch of the thermal equilibrium curve, in the model with three absorbers all of the components lie on stable branches of the curve. This gives further plausibility to a multi-phase absorber.

  3. Effect of shape reactivity on the rod-ejection accident

    SciTech Connect (OSTI)

    Neogy, P.; Carew, J.F.

    1982-09-01T23:59:59.000Z

    The shape reactivity has a significant influence on the rod ejection accident. After the control rod is fully ejected from the core, the neutron flux undergoes a large reduction at the ejected rod location. The corresponding effect on the control reactivity is comparable in magnitude to the Doppler reactivity, and makes a significant contribution to limiting the power excursion during the transient. The neglect of this effect in point kinetics and space time synthesis analyses of the rod ejection accident may account in part for the large degree of conservatism usually associated with these analyses.

  4. Dijet asymmetry in Pb+Pb collisions at $\\sqrt{s_{_{\\rm NN}}}$ = 2.76 TeV within a multiphase transport model

    E-Print Network [OSTI]

    Guo-Liang Ma

    2013-06-04T23:59:59.000Z

    Within a multi-phase transport (AMPT) model, dijet asymmetry is studied in Pb+Pb collisions at $\\sqrt{s_{_{\\rm NN}}}$ = 2.76 TeV. It is found that a large dijet asymmetry ($A_{J}$) is produced by strong interactions between jets and partonic matter. It is demonstrated that hadronization and final-state hadronic rescatterings have little effects on $A_{J}$. The final $A_{J}$ is found to be driven by both initial $A_{J}$ and partonic jet energy loss, which is consistent with an increasing jet energy loss in a hot and strongly interacting partonic medium in more central Pb+Pb collisions.

  5. Reactive Blast Waves from Composite Charges

    SciTech Connect (OSTI)

    Kuhl, A L; Bell, J B; Beckner, V E

    2009-10-16T23:59:59.000Z

    Investigated here is the performance of composite explosives - measured in terms of the blast wave they drive into the surrounding environment. The composite charge configuration studied here was a spherical booster (1/3 charge mass), surrounded by aluminum (Al) powder (2/3 charge mass) at an initial density of {rho}{sub 0} = 0.604 g/cc. The Al powder acts as a fuel but does not detonate - thereby providing an extreme example of a 'non-ideal' explosive (where 2/3 of the charge does not detonate). Detonation of the booster charge creates a blast wave that disperses the Al powder and ignites the ensuing Al-air mixture - thereby forming a two-phase combustion cloud embedded in the explosion. Afterburning of the booster detonation products with air also enhances and promotes the Al-air combustion process. Pressure waves from such reactive blast waves have been measured in bomb calorimeter experiments. Here we describe numerical simulations of those experiments. A Heterogeneous Continuum Model was used to model the dispersion and combustion of the Al particle cloud. It combines the gasdynamic conservation laws for the gas phase with a dilute continuum model for the dispersed phase, as formulated by Nigmatulin. Inter-phase mass, momentum and energy exchange are prescribed by phenomenological models of Khasainov. It incorporates a combustion model based on mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gasdynamic fields, along with a model for mass transfer from the particle phase to the gas. The model takes into account both the afterburning of the detonation products of the booster with air, and the combustion of the Al particles with air. The model equations were integrated by high-order Godunov schemes for both the gas and particle phases. Adaptive Mesh Refinement (AMR) was used to capture the energy-bearing scales of the turbulent flow on the computational grid, and to track/resolve reaction zones. Numerical simulations of the explosion fields from 1.5-g and 10-kg composite charges were performed. Computed pressure histories (red curve) are compared with measured waveforms (black curves) in Fig. 1. Comparison of these results with a waveform for a non-combustion case in nitrogen (blue curve) demonstrates that a reactive blast wave was formed. Cross-sectional views of the temperature field at various times are presented in Fig. 2, which shows that the flow is turbulent. Initially, combustion occurs at the fuel-air interface, and the energy release rate is controlled by the rate of turbulent mixing. Eventually, oxidizer becomes distributed throughout the cloud via ballistic mixing of the particles with air; energy release then occurs in a distributed combustion mode, and Al particle kinetics controls the energy release rate. Details of the Heterogeneous Continuum Model and results of the numerical simulations of composite charge explosions will be described in the paper.

  6. automatic reactive power: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    a radio signal as soon Ning, Peng 62 Active and Reactive Power Control of a DFIG for Variable Speed Wind Energy Conversion using a New Controller CiteSeer Summary: This paper...

  7. Local Control of Reactive Power by Distributed Photovoltaic Generators

    E-Print Network [OSTI]

    Turitsyn, Konstantin S; Backhaus, Scott; Chertkov, Misha

    2010-01-01T23:59:59.000Z

    High penetration levels of distributed photovoltaic (PV) generation on an electrical distribution circuit may severely degrade power quality due to voltage sags and swells caused by rapidly varying PV generation during cloud transients coupled with the slow response of existing utility compensation and regulation equipment. Although not permitted under current standards for interconnection of distributed generation, fast-reacting, VAR-capable PV inverters may provide the necessary reactive power injection or consumption to maintain voltage regulation under difficult transient conditions. As side benefit, the control of reactive power injection at each PV inverter provides an opportunity and a new tool for distribution utilities to optimize the performance of distribution circuits, e.g. by minimizing thermal losses. We suggest a local control scheme that dispatches reactive power from each PV inverter based on local instantaneous measurements of the real and reactive components of the consumed power and the re...

  8. Reactive DC magnetron sputtering of ultrathin superconducting niobium nitride films

    E-Print Network [OSTI]

    Dane, Andrew E. (Andrew Edward)

    2015-01-01T23:59:59.000Z

    DC reactive magnetron sputtering was used to deposit few-nanometer-thick films of niobium nitride for fabrication of superconducting devices. Over 1000 samples were deposited on a variety of substrates, under various chamber ...

  9. Evaluation of Methods to Predict Reactivity of Gold Nanoparticles...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    relationship to the concept of frontier molecular orbital theory. The d-band theory of Hammer and Nørskov is perhaps the most widely used predictor of reactivity on metallic...

  10. Pre-plated reactive diffusion-bonded battery electrode plaques

    DOE Patents [OSTI]

    Maskalick, Nicholas J. (Pittsburgh, PA)

    1984-01-01T23:59:59.000Z

    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.

  11. Reactive oxygen species: a breath of life or death?

    E-Print Network [OSTI]

    Fruehauf, John P; Meyskens, Frank L Jr

    2007-01-01T23:59:59.000Z

    AP1, activator protein-1; ODD, oxygen-dependent degradationSignaling response when oxygen levels decrease (Fig. 1C;3. Halliwell B. Reactive oxygen species in living sys- tems:

  12. Dynamic Reactive Power Control of Isolated Power Systems

    E-Print Network [OSTI]

    Falahi, Milad

    2012-10-03T23:59:59.000Z

    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...

  13. Learning Structured Reactive Navigation Plans from Executing MDP Navigation Policies

    E-Print Network [OSTI]

    Cremers, Daniel

    Learning Structured Reactive Navigation Plans from Executing MDP Navigation Policies Michael Beetz, beetz,belker@cs.uni-bonn.de Abstract. Autonomous robots, such as robot office couriers, need navigation

  14. Conversion of carboxylate salts to carboxylic acids via reactive distillation 

    E-Print Network [OSTI]

    Williamson, Shelly Ann

    2000-01-01T23:59:59.000Z

    , municipal solid wastes, sewage sludge, and industrial biosludge. Using a proprietary technology owned by Texas A&M University the wastes are first treated with lime to enhance reactivity. Then they are converted to calcium carboxylate salts using a mixed...

  15. Evolution of Memory in Reactive Artificial Neural Networks

    E-Print Network [OSTI]

    Chung, Ji Ryang

    2012-07-16T23:59:59.000Z

    in the context of evolution: how reactive agents could have evolved into cognitive ones with internalized memory? This study strives to find an answer to the question by simulating neuroevolution on artificial neural networks, with the hypothesis...

  16. Application of the ''reactivity constraint approach'' to automatic reactor control

    SciTech Connect (OSTI)

    Bernard, J.A.; Henry, A.F.; Lanning, D.D.

    1988-02-01T23:59:59.000Z

    The ''reactivity constraint approach'' is described and demonstrated to be an effective and reliable means for the automatic control of power in nuclear reactors. This approach functions by restricting the effect of the delayed neutron populations to that which can be balanced by an induced change in the prompt population. This is done by limiting the net reactivity to the amount that can be offset by reversing the direction of motion of the automated control mechanism. The necessary reactivity constraints are obtained from the dynamic period equation, which gives the instantaneous reactor period as a function of the reactivity and the rate of change of reactivity. The derivation of this equation is described with emphasis on the recently obtained ''alternate'' formulation. Following a discussion of the behavior of each term of this alternate equation as a function of reactivity, its use in the design and operation of a nonlinear, closed-loop, digital controller for reactor power is in the design and operation of a nonlinear, closed-loop, digital controller for reactor power is described. Details of the initial experimental trials of the resulting controller are given.

  17. Semi-Analytical Solutions of One-Dimensional Multispecies Reactive Transport in a Permeable Reactive Barrier-Aquifer System

    E-Print Network [OSTI]

    Mieles, John Michael

    2012-07-16T23:59:59.000Z

    At many sites it has become apparent that most chemicals of concern (COCs) in groundwater are persistent and not effectively treated by conventional remediation methods. In recent years, the permeable reactive barrier (PRB) technology has proven...

  18. Determining conductivity and mobility values of individual components in multiphase composite Cu{sub 1.97}Ag{sub 0.03}Se

    SciTech Connect (OSTI)

    Day, Tristan W.; Brown, David R.; Snyder, G. Jeffrey, E-mail: jsnyder@caltech.edu [Department of Materials Science, California Institute of Technology, MC 309-81, Pasadena, California 91106 (United States); Zeier, Wolfgang G. [Department of Materials Science, California Institute of Technology, MC 309-81, Pasadena, California 91106 (United States); Department of Chemistry, University of Southern California, Seeley G. Mudd Bldg., 3620 McClintock Ave., Los Angeles, California 90089-1062 (United States); Melot, Brent C. [Department of Chemistry, University of Southern California, Seeley G. Mudd Bldg., 3620 McClintock Ave., Los Angeles, California 90089-1062 (United States)

    2014-10-27T23:59:59.000Z

    The intense interest in phase segregation in thermoelectrics as a means to reduce the lattice thermal conductivity and to modify the electronic properties from nanoscale size effects has not been met with a method for separately measuring the properties of each phase assuming a classical mixture. Here, we apply effective medium theory for measurements of the in-line and Hall resistivity of a multiphase composite, in this case Cu{sub 1.97}Ag{sub 0.03}Se. The behavior of these properties with magnetic field as analyzed by effective medium theory allows us to separate the conductivity and charge carrier mobility of each phase. This powerful technique can be used to determine the matrix properties in the presence of an unwanted impurity phase, to control each phase in an engineered composite, and to determine the maximum carrier concentration change by a given dopant, making it the first step toward a full optimization of a multiphase thermoelectric material and distinguishing nanoscale effects from those of a classical mixture.

  19. Application of Partial-Order Methods to Reactive Programs with Event Memorization

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    with event memorization. The reactive systems are specified with an asynchronous reactive language Electre, 3 (2001) 287-316" #12;2 Electre: an Asynchronous Reactive Language with Event Memorization 3 2 of a semantic model of an asyn- chronous reactive language: Electre [PRH92, CR95]. Indeed, this language

  20. DEVELOPMENT OF A COMPUTATIONAL MULTIPHASE FLOW MODEL FOR FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR

    SciTech Connect (OSTI)

    Donna Post Guillen; Tami Grimmett; Anastasia M. Gribik; Steven P. Antal

    2010-09-01T23:59:59.000Z

    The Hybrid Energy Systems Testing (HYTEST) Laboratory is being established at the Idaho National Laboratory to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions will be performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. SBCRs are cylindrical vessels in which gaseous reactants (for example, synthesis gas or syngas) is sparged into a slurry of liquid reaction products and finely dispersed catalyst particles. The catalyst particles are suspended in the slurry by the rising gas bubbles and serve to promote the chemical reaction that converts syngas to a spectrum of longer chain hydrocarbon products, which can be upgraded to gasoline, diesel or jet fuel. These SBCRs operate in the churn-turbulent flow regime which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer, that effect reactor performance. The purpose of this work is to develop a computational multiphase fluid dynamic (CMFD) model to aid in understanding the physico-chemical processes occurring in the SBCR. Our team is developing a robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) that includes twelve species: (1) CO reactant, (2) H2 reactant, (3) hydrocarbon product, and (4) H2O product in small bubbles, large bubbles, and the bulk fluid. Properties of the hydrocarbon product were specified by vapor liquid equilibrium calculations. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is determined based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield [1]. The model includes heat generation due to the exothermic chemical reaction, as well as heat removal from a constant temperature heat exchanger. Results of the CMFD simulations (similar to those shown in Figure 1) will be presented.

  1. Environmentally stable reactive alloy powders and method of making same

    DOE Patents [OSTI]

    Anderson, I.E.; Lograsso, B.K.; Terpstra, R.L.

    1998-09-22T23:59:59.000Z

    Apparatus and method are disclosed for making powder from a metallic melt by atomizing the melt to form droplets and reacting the droplets downstream of the atomizing location with a reactive gas. The droplets are reacted with the gas at a temperature where a solidified exterior surface is formed thereon and where a protective refractory barrier layer (reaction layer) is formed whose penetration into the droplets is limited by the presence of the solidified surface so as to avoid selective reduction of key reactive alloys needed to achieve desired powder end use properties. The barrier layer protects the reactive powder particles from environmental constituents such as air and water in the liquid or vapor form during subsequent fabrication of the powder to end-use shapes and during use in the intended service environment. 7 figs.

  2. Options for Control of Reactive Power by Distributed Photovoltaic Generators

    E-Print Network [OSTI]

    Sulc, Petr; Backhaus, Scott; Chertkov, Michael

    2010-01-01T23:59:59.000Z

    High penetration levels of distributed photovoltaic(PV) generation on an electrical distribution circuit present several challenges and opportunities for distribution utilities. Rapidly varying irradiance conditions may cause voltage sags and swells that cannot be compensated by slowly responding utility equipment resulting in a degradation of power quality. Although not permitted under current standards for interconnection of distributed generation, fast-reacting, VAR-capable PV inverters may provide the necessary reactive power injection or consumption to maintain voltage regulation under difficult transient conditions. As side benefit, the control of reactive power injection at each PV inverter provides an opportunity and a new tool for distribution utilities to optimize the performance of distribution circuits, e.g. by minimizing thermal losses. We discuss and compare via simulation various design options for control systems to manage the reactive power generated by these inverters. An important design de...

  3. Apparatus for making environmentally stable reactive alloy powders

    DOE Patents [OSTI]

    Anderson, I.E.; Lograsso, B.K.; Terpstra, R.L.

    1996-12-31T23:59:59.000Z

    Apparatus and method are disclosed for making powder from a metallic melt by atomizing the melt to form droplets and reacting the droplets downstream of the atomizing location with a reactive gas. The droplets are reacted with the gas at a temperature where a solidified exterior surface is formed thereon and where a protective refractory barrier layer (reaction layer) is formed whose penetration into the droplets is limited by the presence of the solidified surface so as to avoid selective reduction of key reactive alloyants needed to achieve desired powder end use properties. The barrier layer protects the reactive powder particles from environmental constituents such as air and water in the liquid or vapor form during subsequent fabrication of the powder to end-use shapes and during use in the intended service environment. 7 figs.

  4. Physical Separation and Multiphase

    E-Print Network [OSTI]

    Sóbester, András

    - research into CVD and HVOF coatings for subsea choke valve applications. s US Navy - understanding the processes of charge generation in gear contacts as a predictive maintenance tool. s DRA/UoS - corrosion

  5. Dielectric covered hairpin probe for its application in reactive plasmas

    SciTech Connect (OSTI)

    Gogna, G. S.; Gaman, C.; Turner, M. M. [NCPST, School of Physical Sciences, Dublin City University, Dublin 9 (Ireland); Karkari, S. K. [Institute for Plasma Research Center, Bhat Gandhinagar, Gujarat 382428 (India)

    2012-07-23T23:59:59.000Z

    The hairpin probe is a well known technique for measuring local electron density in low temperature plasmas. In reactive plasmas, the probe characteristics are affected by surface sputtering, contamination, and secondary electron emission. At higher densities, the plasma absorbs the entire electromagnetic energy of hairpin and hence limits the density measurements. These issues can be resolved by covering the hairpin surface with a thin layer of dielectric. In this letter, the dielectric contribution to the probe characteristics is incorporated in a theory which is experimentally verified. The dielectric covering improves the performance of probe and also allows the hairpin tip to survive in reactive plasma where classical electrical probes are easily damaged.

  6. Plasma & reactive ion etching to prepare ohmic contacts

    DOE Patents [OSTI]

    Gessert, Timothy A. (Conifer, CO)

    2002-01-01T23:59:59.000Z

    A method of making a low-resistance electrical contact between a metal and a layer of p-type CdTe surface by plasma etching and reactive ion etching comprising: a) placing a CdS/CdTe layer into a chamber and evacuating said chamber; b) backfilling the chamber with Argon or a reactive gas to a pressure sufficient for plasma ignition; and c) generating plasma ignition by energizing a cathode which is connected to a power supply to enable the plasma to interact argon ions alone or in the presence of a radio-frequency DC self-bias voltage with the p-CdTe surface.

  7. The relative reactivity of formic esters with aromatic amines

    E-Print Network [OSTI]

    Markley, Max C.

    1922-01-01T23:59:59.000Z

    .MARKLEY I Vies* S ma y c . l k f c V i M t s RDQOSS 38M30 PREFACE. The purpose of this thesis was to determine the relative reactivity between aromatic amines and the esters of formic acid.It was proposed to first: deter­ mine the reactivity... be given Br .Ray Q,.Brewster , the director of this work, for his help and directions for carrying out this work, and to Br.Prank B.Bains for his kind assistance in many ways. 1.Broil,Journal fur Practische Chemie,1875,vol. 12,page 208. ( 2 ) TABLE...

  8. Notes on Well-Posed, Ensemble Averaged Conservation Equations for Multiphase, Multi-Component, and Multi-Material Flows

    SciTech Connect (OSTI)

    Ray A. Berry

    2005-07-01T23:59:59.000Z

    At the INL researchers and engineers routinely encounter multiphase, multi-component, and/or multi-material flows. Some examples include: Reactor coolant flows Molten corium flows Dynamic compaction of metal powders Spray forming and thermal plasma spraying Plasma quench reactor Subsurface flows, particularly in the vadose zone Internal flows within fuel cells Black liquor atomization and combustion Wheat-chaff classification in combine harvesters Generation IV pebble bed, high temperature gas reactor The complexity of these flows dictates that they be examined in an averaged sense. Typically one would begin with known (or at least postulated) microscopic flow relations that hold on the “small” scale. These include continuum level conservation of mass, balance of species mass and momentum, conservation of energy, and a statement of the second law of thermodynamics often in the form of an entropy inequality (such as the Clausius-Duhem inequality). The averaged or macroscopic conservation equations and entropy inequalities are then obtained from the microscopic equations through suitable averaging procedures. At this stage a stronger form of the second law may also be postulated for the mixture of phases or materials. To render the evolutionary material flow balance system unique, constitutive equations and phase or material interaction relations are introduced from experimental observation, or by postulation, through strict enforcement of the constraints or restrictions resulting from the averaged entropy inequalities. These averaged equations form the governing equation system for the dynamic evolution of these mixture flows. Most commonly, the averaging technique utilized is either volume or time averaging or a combination of the two. The flow restrictions required for volume and time averaging to be valid can be severe, and violations of these restrictions are often found. A more general, less restrictive (and far less commonly used) type of averaging known as ensemble averaging can also be used to produce the governing equation systems. In fact volume and time averaging can be viewed as special cases of ensemble averaging. Ensemble averaging is beginning to gain some notice, for example the general-purpose multi-material flow simulation code CFDLib under continuing developed at the Los Alamos National Laboratory [Kashiwa and Rauenzahn 1994] is based on an ensemble averaged formulation. The purpose of this short note is to give an introduction to the ensemble averaging methodology and to show how ensemble averaged balance equations and entropy inequality can be obtained from the microscopic balances. It then details some seven-equation, two-pressure, two-velocity hyperbolic, well-posed models for two-phase flows. Lastly, a simple example is presented of a model in which the flow consists of two barotropic fluids with no phase change in which an equilibrium pressure equation is obtained in the spirit of pressure-based methods of computational fluid dynamics.

  9. Medium modifications of jet shapes in Pb+Pb collisions at $\\sqrt{s_{_{\\rm NN}}}$ = 2.76 TeV within a multiphase transport model

    E-Print Network [OSTI]

    Guo-Liang Ma

    2014-02-06T23:59:59.000Z

    Within a multiphase transport model, medium modifications of differential jet shapes are investigated in Pb+Pb collisions at $\\sqrt{s_{_{\\rm NN}}}$ = 2.76 TeV. The differential jet shapes are significantly modified by the strong interactions between jets and a partonic medium in Pb+Pb collisions relative to that in p+p collisions. The modifications are slightly weakened by the hadronization of coalescence, but strengthened by resonance decays in hadronic rescatterings. Subleading jets display larger medium modifications than leading jets, especially in central Pb+Pb collisions with large dijet asymmetries. These behaviors of medium modifications of differential jet shapes reflect a dynamical evolution of redistribution of jet energy inside a quenched jet cone in high-energy heavy-ion collisions.

  10. Device and method for measuring multi-phase fluid flow and density of fluid in a conduit having a gradual bend

    DOE Patents [OSTI]

    Ortiz, M.G.; Boucher, T.J.

    1998-10-27T23:59:59.000Z

    A system is described for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.

  11. Monitoring CO 2 sequestration into deep saline aquifer and associated salt intrusion using coupled multiphase flow modeling and time lapse electrical resistivity tomography

    SciTech Connect (OSTI)

    Chuan Lu; CHI Zhang; Hai Hanag; Timothy C. Johnson

    2014-04-01T23:59:59.000Z

    Successful geological storage and sequestration of carbon dioxide (CO2) require efficient monitoring of the migration of CO2 plume during and after large-scale injection in order to verify the containment of the injected CO2 within the target formation and to evaluate potential leakage risk. Field studies have shown that surface and cross-borehole electrical resistivity tomography (ERT) can be a useful tool in imaging and characterizing solute transport in heterogeneous subsurface. In this synthetic study, we have coupled a 3-D multiphase flow model with a parallel 3-D time-lapse ERT inversion code to explore the feasibility of using time-lapse ERT for simultaneously monitoring the migration of CO2 plume in deep saline formation and potential brine intrusion into shallow fresh water aquifer. Direct comparisons of the inverted CO2 plumes resulting from ERT with multiphase flow simulation results indicate the ERT could be used to delineate the migration of CO2 plume. Detailed comparisons on the locations, sizes and shapes of CO2 plume and intruded brine plumes suggest that ERT inversion tends to underestimate the area review of the CO2 plume, but overestimate the thickness and total volume of the CO2 plume. The total volume of intruded brine plumes is overestimated as well. However, all discrepancies remain within reasonable ranges. Our study suggests that time-lapse ERT is a useful monitoring tool in characterizing the movement of injected CO2 into deep saline aquifer and detecting potential brine intrusion under large-scale field injection conditions.

  12. Non-Energetic Reactive Armor (NERA) and Semi-Energetic Reactive Armor (SERA) FY13 Final Report

    SciTech Connect (OSTI)

    Ben Langhorst; Nikki Rasmussen; Andrew Robinson

    2013-08-01T23:59:59.000Z

    INL researchers have proposed prototypes for future lightweight armor systems that reside in a technology gap between explosive reactive armor and passive armor. The targets were designed to react under impact and throw a steel front plate into the path of the projectile, forcing the projectile to engage more of the front plate during its penetration process. These prototypes are intended to exhibit the enhanced efficiency of explosive reactive armor without the collateral damage often associated with explosive reactive armor. One of the prototype systems, Semi Energetic Reactive Armor (SERA), functions similarly to explosive reactive armor, but features a reactive material that reacts much slower than explosive reactive armor. Two different SERA test groups were built and featuring different ratios of aluminum Teflon(copyright) powders pressed into 0.5 in. thick energetic tiles and sandwiched between 0.25 in. thick RHA plates. The other prototype system, Non Energetic Reactive Armor (NERA), utilizes the strain energy in compressed rubber to launch a front flyer plate into the path of an incoming projectile. It is comprised of a 1 in. thick rubber layer sandwiched between two 0.25 in. thick RHA plates with bolt holes around the perimeter. Bolts are inserted through the entire target and tightened to compress the rubber sheet to significant strain levels (approximately 40%). A fourth group of targets was tested as a control group. It featured a 0.5 in. thick rubber sheet sandwiched between two 0.25 in. thick RHA plates, similar to the NERA test articles, but the rubber is uncompressed. The four test groups (uncompressed rubber, compressed rubber, 70/30 Al/PTFE, 50/50 Al/PTFE) were each fabricated with three identical test articles in each group. All twelve targets were subjected to ballistic testing at the National Security Test Range on July 17, 2013. They were tested with 0.5 in. diameter steel rods shot at a consistent velocity at each target. In order to characterize the energetic materials, break wires were embedded in the targets and burn velocities were measured. The residual mass method was used to compare the target performance of each group and final performance data is presented below.

  13. Effect of Number of Fractionating Trays on Reactive Distillation Performance

    E-Print Network [OSTI]

    Al-Arfaj, Muhammad A.

    Effect of Number of Fractionating Trays on Reactive Distillation Performance Muhammad A. Al and rectifying sec- tions of a reacti®e distillation column can degrade performance. This effect, if true®e distillation columns cannot use conser®ati®e estimates of tray numbers, that is, we cannot simply add excess

  14. Abduction with Negation as Failure for Active and Reactive Rules

    E-Print Network [OSTI]

    Toni, Francesca

    Abduction with Negation as Failure for Active and Reactive Rules Fariba Sadri and Francesca Toni suggested abductive logic programming as a suitable formalism to represent active databases and intelligent agents. In particular, abducibles in abductive logic programs can be used to repre- sent actions

  15. Author's personal copy Reactivity of lithium exposed graphite surface

    E-Print Network [OSTI]

    Harilal, S. S.

    on the surface [18]. Hence the effect of lithium on plasma­wall interactions is expected to dependAuthor's personal copy Reactivity of lithium exposed graphite surface S.S. Harilal a, *, J in fusion devices [1­5]. For example, wall conditioning with thin lithium layers gives rise to low hydrogen

  16. MARKETS FOR REACTIVE POWER AND RELIABILITY: A WHITE PAPER

    E-Print Network [OSTI]

    1 MARKETS FOR REACTIVE POWER AND RELIABILITY: A WHITE PAPER Engineering and Economics of Electricity Research Group (E3 RG) CORNELL UNIVERSITY E3 RG contributing authors: Robert Thomas, Director the Consortium for Electric Reliability Technology Solutions (CERTS) and in part by the National Science

  17. Melting Alpine Glaciers Enrich High-Elevation Lakes with Reactive

    E-Print Network [OSTI]

    Williamson, Craig E.

    Melting Alpine Glaciers Enrich High-Elevation Lakes with Reactive Nitrogen J A S M I N E E . S A R received May 26, 2010. Accepted May 28, 2010. Alpine glaciers have receded substantially over the last. Our results demonstrate that the presence of glaciers on alpine watersheds more strongly influences NO

  18. Local control of reactive power by distributed photovoltaic generators

    SciTech Connect (OSTI)

    Chertkov, Michael [Los Alamos National Laboratory; Turitsyn, Konstantin [Los Alamos National Laboratory; Sulc, Petr [Los Alamos National Laboratory; Backhaus, Scott [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    High penetration levels of distributed photovoltaic (PV) generation on an electrical distribution circuit may severely degrade power quality due to voltage sags and swells caused by rapidly varying PV generation during cloud transients coupled with the slow response of existing utility compensation and regulation equipment. Although not permitted under current standards for interconnection of distributed generation, fast-reacting, VAR-capable PV inverters may provide the necessary reactive power injection or consumption to maintain voltage regulation under difficult transient conditions. As side benefit, the control of reactive power injection at each PV inverter provides an opportunity and a new tool for distribution utilities to optimize the performance of distribution circuits, e.g. by minimizing thermal losses. We suggest a local control scheme that dispatches reactive power from each PV inverter based on local instantaneous measurements of the real and reactive components of the consumed power and the real power generated by the PVs. Using one adjustable parameter per circuit, we balance the requirements on power quality and desire to minimize thermal losses. Numerical analysis of two exemplary systems, with comparable total PV generation albeit a different spatial distribution, show how to adjust the optimization parameter depending on the goal. Overall, this local scheme shows excellent performance; it's capable of guaranteeing acceptable power quality and achieving significant saving in thermal losses in various situations even when the renewable generation in excess of the circuit own load, i.e. feeding power back to the higher-level system.

  19. Dynamic Reactive Power Control of Isolated Power Systems 

    E-Print Network [OSTI]

    Falahi, Milad

    2012-10-03T23:59:59.000Z

    .................................................................................................... 175? 5.1.? Introduction ............................................................................................. 175? 5.2.? Photovoltaic Source ................................................................................. 176? 5.3.? DFIG... .............................................................................. 53 Figure 3-3 Discrete hybrid automata [78] ................................................................... 55 Figure 3-4 Injection and withdrawal of reactive power from bus n ............................ 69 Figure 3-5 Converting the system...

  20. Active and reactive power in stochastic resonance for energy harvesting

    E-Print Network [OSTI]

    Kubota, Madoka; Hikihara, Takashi

    2015-01-01T23:59:59.000Z

    A power allocation to active and reactive power in stochastic resonance is discussed for energy harvesting from mechanical noise. It is confirmed that active power can be increased at stochastic resonance, in the same way of the relationship between energy and phase at an appropriate setting in resonance.

  1. Structuring and Design of Reactive Systems using RSDS and B

    E-Print Network [OSTI]

    Clark, David

    for the automatic synthesis of controllers from invariants. A case study of a train control system is used, which is aimed at reactive control system development. We define strategies for controller decomposition to illustrate the ideas. #12; 1 Introduction A control algorithm for a discrete event system describes

  2. Field, Laboratory, and Modeling Study of Reactive Transport of

    E-Print Network [OSTI]

    University of New York, Flushing, New York 11367, Department of Marine Chemistry and Geochemistry, Woods Hole Bay, MA, shed light on coupled control of chemistry and hydrology on reactive transport), phosphate (5), and oxyanions of molybdenum (6) and uranium (7, 8) in aquifers. In addition

  3. Surface tension in a reactive binary mixture of incompressible fluids

    E-Print Network [OSTI]

    Struchtrup, Henning

    Surface tension in a reactive binary mixture of incompressible fluids Henning Struchtrup Institute with a distributed form of surface tension. The model describes chemistry, diffusion, viscosity and heat transfer tension at the front. Keywords: Binary mixtures, Surface tension, Irreversible thermodynamics, Hele

  4. Nitrogen dynamics in flow-through microcosms of reactive media.

    E-Print Network [OSTI]

    Vallino, Joseph J.

    wastewater inputs to estuaries is similarly an important issue. Individual wastewater treatments have been University, Worcester MA December 19, 2005 Marine Biological Laboratory 1 #12;Abstract There have been many, the Marine Biological Laboratory is currently testing two experimental permeable reactive barriers along

  5. December 13, 2012 The steady state model of a reactive distillation column for ethylene glycol

    E-Print Network [OSTI]

    Neumaier, Arnold

    December 13, 2012 The steady state model of a reactive distillation column for ethylene glycol in an ethylene glycol reactive distillation column. Ind. Eng. Chem. Res., 33:2738­2748, 1994. 3 #12;

  6. Hydrogen Reactivity on Highly-hydroxylated TiO2(110) Surfaces...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Reactivity on Highly-hydroxylated TiO2(110) Surfaces Prepared via Carboxylic Acid Adsorption and Photolysis. Hydrogen Reactivity on Highly-hydroxylated TiO2(110) Surfaces Prepared...

  7. Reactive Transport Modeling and Geophysical Monitoring of Bioclogging at Reservoir Scale

    E-Print Network [OSTI]

    Hubbard, Susan

    Reactive Transport Modeling and Geophysical Monitoring of Bioclogging at Reservoir Scale Vikranth scale using a combination of reactive transport modeling and geophysical imaging tools (EM & seismic Sacramento basin, California; the model well (Citizen Green #1) was characterized using sonic, electrical

  8. An Aircraft Electric Power Testbed for Validating Automatically Synthesized Reactive Control Protocols

    E-Print Network [OSTI]

    Xu , Huan

    An Aircraft Electric Power Testbed for Validating Automatically Synthesized Reactive Control reactive synthesis; testbed; aircraft electric power system 1. INTRODUCTION AND MOTIVATION Aircraft of Pennsylvania utopcu@seas.upenn.edu ABSTRACT Modern aircraft increasingly rely on electric power for sub

  9. Stabilization of liquid crystal photoaligning layers by reactive mesogens O. Yaroshchuk,1

    E-Print Network [OSTI]

    Stabilization of liquid crystal photoaligning layers by reactive mesogens O. Yaroshchuk,1 V photoaligning layers by thin layers of reactive mesogens, strong enhancement in LC alignment stability layer, the photoalignment technique minimizes me- chanical damage and electric charging, provides

  10. Pollution-enhanced reactive chlorine chemistry in the eastern tropical Atlantic boundary layer

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    doi:10.1029/2008GL036666, 2009 Pollution-enhanced reactiveE. S. Saltzman (2009), Pollution-enhanced reactive chlorine5 L08810 LAWLER ET AL. : POLLUTION-ENHANCED CLX IN THE MBL

  11. Chemical Reactivity of Reduced TiO2(110): The dominant role of...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Reactivity of Reduced TiO2(110): The dominant role of surface defects in oxygen chemisorption. Chemical Reactivity of Reduced TiO2(110): The dominant role of surface defects in...

  12. Control Study of Ethyl tert-Butyl Ether Reactive Distillation Muhammad A. Al-Arfaj

    E-Print Network [OSTI]

    Al-Arfaj, Muhammad A.

    Control Study of Ethyl tert-Butyl Ether Reactive Distillation Muhammad A. Al-Arfaj Department structures for ethyl tert-butyl ether (ETBE) reactive distillation columns are studied. Two process The use of reactive distillation has grown in recent years because it results in less expensive and more

  13. Analytical solutions for sequentially coupled one-dimensional reactive transport problems Part I: Mathematical derivations

    E-Print Network [OSTI]

    Clement, Prabhakar

    Analytical solutions for sequentially coupled one-dimensional reactive transport problems ­ Part I-species reactive transport equations coupled through sorption and sequential first-order reactions are commonly. Although researchers have been attempting to solve various forms of these reactive transport equations

  14. VOF-BASED SIMULATION OF REACTIVE MASS TRANSFER ACROSS DEFORMABLE INTERFACES

    E-Print Network [OSTI]

    Bothe, Dieter

    . of the bubbles is there- fore of fundamental importance for effective design of the reactor. In case of fast-based approach for the Direct Numerical Simulation of reactive mass transfer in gas-liquid flows is described simulation results are presented for non reactive and reactive mass transfer from rising gas bubbles

  15. Reactive Power Operation Analysis of a Single-Phase EV/PHEV Bidirectional Battery Charger

    E-Print Network [OSTI]

    Tolbert, Leon M.

    of the electric grid by supplying ancillary services such as reactive power compensation, voltage regulation, charger, electric vehicle, EV, PHEV, reactive power, V2G. I. INTRODUCTION According to the internationalReactive Power Operation Analysis of a Single-Phase EV/PHEV Bidirectional Battery Charger Mithat C

  16. Using Reactive Rules to Guide a Forward-Chaining Murray Shanahan

    E-Print Network [OSTI]

    Shanahan, Murray

    1 Using Reactive Rules to Guide a Forward-Chaining Planner Murray Shanahan Department of Electrical.shanahan@ic.ac.uk Keywords: planning and execution, reactive planning, robot planning Abstract This paper presents a planning technique in which a flawed set of reactive rules is used to guide a stochastic forward-chaining search

  17. A pulser for medium-frequency modulated direct-current reactive sputter deposition of insulators

    E-Print Network [OSTI]

    Cao, Hui

    for medium-frequency modulated direct-current dc reactive sputter deposition of electrical insulators at the target surface inherent to high- deposition-rate reactive sputtering of electrical insulators. TypicallyA pulser for medium-frequency modulated direct-current reactive sputter deposition of insulators G

  18. Abstract This paper reviews specific issues and challenges in reactive power management within the competitive electricity

    E-Print Network [OSTI]

    Gross, George

    and physical considerations and so depends on the market players and the electricity market rules. Reactive local nature of reactive power restricts its ability to be transmitted over electrically large distancesAbstract ­ This paper reviews specific issues and challenges in reactive power management within

  19. CARIBBEAN COLLOQUIUM ON POWER QUALITY (CCPQ), JUNE 2003 100 Defining Reactive Power in Circuit Transients via

    E-Print Network [OSTI]

    Stankoviæ, Aleksandar

    CARIBBEAN COLLOQUIUM ON POWER QUALITY (CCPQ), JUNE 2003 100 Defining Reactive Power in Circuit the notion of reactive power during circuit transients. The definition we propose is based on the concept, namely Short- Time Fourier Coefficients and Haar Wavelets. We illustrate this "dynamic" reactive power

  20. Finite Bisimulation of Reactive Untimed Infinite State Systems Modeled as Automata with Variables

    E-Print Network [OSTI]

    Kumar, Ratnesh

    1 Finite Bisimulation of Reactive Untimed Infinite State Systems Modeled as Automata with Variables for reactive untimed infinite state systems called input- output extended finite automaton (I/O-EFA), which of a finite bisimilar abstraction. The results are illustrated through examples that model reactive software

  1. Examination of a PHEV Bidirectional Charger System for V2G Reactive Power Compensation

    E-Print Network [OSTI]

    Tolbert, Leon M.

    . Keywords - PHEV; charger; V2G; reactive power; battery I. INTRODUCTION Today, hybrid electric vehicles and shows how to control the on-board vehicle charger to provide reactive power to the electric grid is not engaged in reactive power transfer. II. ELECTRIC VEHICLE CHARGERS Battery chargers play an important role

  2. Toward Optimized Bioclogging and Biocementation Through Combining Advanced Geophysical Monitoring and Reactive Transport Modeling

    E-Print Network [OSTI]

    Hubbard, Susan

    and electrical techniques); (ii) developing and using a reactive transport simulator capable of predicting and Reactive Transport Modeling Approaches Christopher G Hubbard1 , Susan S. Hubbard1 , Yuxin Wu1 , Vikranth heterogeneities at the field scale. Optimization of these strategies requires advances in mechanistic reactive

  3. Voltage Control of Distribution Networks with Distributed Generation using Reactive Power

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Voltage Control of Distribution Networks with Distributed Generation using Reactive Power to control voltage of distribution networks with DG using reactive power compensation approach. In this paper profile within the specified limits, it is essential to regulate the reactive power of the compensators

  4. Generation of reactive oxygen species by a persulfide (BnSSH) Tonika Chatterji,

    E-Print Network [OSTI]

    Gates, Kent. S.

    Generation of reactive oxygen species by a persulfide (BnSSH) Tonika Chatterji, Kripa Keerthi generate reactive oxygen species under biologically rele- vant conditions via the sequence of reactions by reactive oxygen species generated in this manner may contribute to the cytotoxic properties of leinamycin

  5. TO APPEAR IN IEEE TRANSACTION ON POWER SYSTEMS 1 Effect of Reactive Power Limit Modeling on

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    TO APPEAR IN IEEE TRANSACTION ON POWER SYSTEMS 1 Effect of Reactive Power Limit Modeling on Maximum System Loading and Active and Reactive Power Markets Behnam Tamimi, Student Member, IEEE, Claudio A. Ca- active power in electric power systems. Although there are other important reactive power sources

  6. Engine combustion control at low loads via fuel reactivity stratification

    DOE Patents [OSTI]

    Reitz, Rolf Deneys; Hanson, Reed M; Splitter, Derek A; Kokjohn, Sage L

    2014-10-07T23:59:59.000Z

    A compression ignition (diesel) engine uses two or more fuel charges during a combustion cycle, with the fuel charges having two or more reactivities (e.g., different cetane numbers), in order to control the timing and duration of combustion. By appropriately choosing 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). At low load and no load (idling) conditions, the aforementioned results are attained by restricting airflow to the combustion chamber during the intake stroke (as by throttling the incoming air at or prior to the combustion chamber's intake port) so that the cylinder air pressure is below ambient pressure at the start of the compression stroke.

  7. Tracking thermal fronts with temperature-sensitive, chemically reactive tracers

    SciTech Connect (OSTI)

    Robinson, B.A.; Birdsell, S.A.

    1987-01-01T23:59:59.000Z

    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.

  8. Reactivity impact of delayed neutron spectra on MCNP calculations

    SciTech Connect (OSTI)

    Mosteller, R.D.; Werner, C.J.

    2000-07-01T23:59:59.000Z

    The new features in MCNP4C, the latest version of the MCNP Monte Carlo code, include the capability to sample from delayed as well as prompt fission emission spectra. Previous versions of MCNP all have sampled exclusively from prompt spectra. Delayed neutrons typically account for <1% of all neutrons emitted from fission, but the emission spectra for delayed neutrons are somewhat softer than those for prompt neutrons. Because of the softer spectrum, delayed neutrons are less likely to leak from the system, and they also are less likely to cause fission in isotopes that have an effective threshold for fission (e.g., {sup 238}U and {sup 240}Pu). Consequently, the inclusion of delayed neutron spectra can have a small but significant effect on reactivity calculations. This study performs MCNP4C calculations for a series of established benchmarks and quantifies the reactivity impact of the delayed neutron spectra.

  9. Revised Knudsen-layer reduction of fusion reactivity

    SciTech Connect (OSTI)

    Albright, B. J.; Molvig, Kim; Huang, C.-K.; Simakov, A. N.; Dodd, E. S.; Hoffman, N. M.; Kagan, G. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States); Schmit, P. F. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185-1186 (United States)] [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185-1186 (United States)

    2013-12-15T23:59:59.000Z

    Recent work by Molvig et al. [Phys. Rev. Lett. 109, 095001 (2012)] examined how fusion reactivity may be reduced from losses of fast ions in finite assemblies of fuel. In this paper, this problem is revisited with the addition of an asymptotic boundary-layer treatment of ion kinetic losses. This boundary solution, reminiscent of the classical Milne problem from linear transport theory, obtains a free-streaming limit of fast ion losses near the boundary, where the diffusion approximation is invalid. Thermonuclear reaction rates have been obtained for the ion distribution functions predicted by this improved model. It is found that while Molvig's “Knudsen distribution function” bounds from above the magnitude of the reactivity reduction, this more accurate treatment leads to less dramatic losses of tail ions and associated reduction of thermonuclear reaction rates for finite fuel volumes.

  10. Catalytic destruction of groundwater contaminants in reactive extraction wells

    DOE Patents [OSTI]

    McNab, Jr., Walt W. (Concord, CA); Reinhard, Martin (Stanford, CA)

    2002-01-01T23:59:59.000Z

    A system for remediating groundwater contaminated with halogenated solvents, certain metals and other inorganic species based on catalytic reduction reactions within reactive well bores. The groundwater treatment uses dissolved hydrogen as a reducing agent in the presence of a metal catalyst, such a palladium, to reduce halogenated solvents (as well as other substituted organic compounds) to harmless species (e.g., ethane or methane) and immobilize certain metals to low valence states. The reactive wells function by removing water from a contaminated water-bearing zone, treating contaminants with a well bore using catalytic reduction, and then reinjecting the treated effluent into an adjacent water-bearing zone. This system offers the advantages of a compact design with a minimal surface footprint (surface facilities) and the destruction of a broad suite of contaminants without generating secondary waste streams.

  11. Parallel computation of multigroup reactivity coefficient using iterative method

    SciTech Connect (OSTI)

    Susmikanti, Mike [Center for Development of Nuclear Informatics, National Nuclear Energy Agency of Indonesia PUSPIPTEK Area, Tangerang (Indonesia)] [Center for Development of Nuclear Informatics, National Nuclear Energy Agency of Indonesia PUSPIPTEK Area, Tangerang (Indonesia); Dewayatna, Winter [Center for Nuclear Fuel Technology, National Nuclear Energy Agency of Indonesia PUSPIPTEK Area, Tangerang (Indonesia)] [Center for Nuclear Fuel Technology, National Nuclear Energy Agency of Indonesia PUSPIPTEK Area, Tangerang (Indonesia)

    2013-09-09T23:59:59.000Z

    One of the research activities to support the commercial radioisotope production program is a safety research target irradiation FPM (Fission Product Molybdenum). FPM targets form a tube made of stainless steel in which the nuclear degrees of superimposed high-enriched uranium. FPM irradiation tube is intended to obtain fission. The fission material widely used in the form of kits in the world of nuclear medicine. Irradiation FPM tube reactor core would interfere with performance. One of the disorders comes from changes in flux or reactivity. It is necessary to study a method for calculating safety terrace ongoing configuration changes during the life of the reactor, making the code faster became an absolute necessity. Neutron safety margin for the research reactor can be reused without modification to the calculation of the reactivity of the reactor, so that is an advantage of using perturbation method. The criticality and flux in multigroup diffusion model was calculate at various irradiation positions in some uranium content. This model has a complex computation. Several parallel algorithms with iterative method have been developed for the sparse and big matrix solution. The Black-Red Gauss Seidel Iteration and the power iteration parallel method can be used to solve multigroup diffusion equation system and calculated the criticality and reactivity coeficient. This research was developed code for reactivity calculation which used one of safety analysis with parallel processing. It can be done more quickly and efficiently by utilizing the parallel processing in the multicore computer. This code was applied for the safety limits calculation of irradiated targets FPM with increment Uranium.

  12. Dynamics of inelastic and reactive gas-surface collisions

    SciTech Connect (OSTI)

    Smoliar, L.A.

    1995-04-01T23:59:59.000Z

    The dynamics of inelastic and reactive collisions in atomic beam-surface scattering are presented. The inelastic scattering of hyperthermal rare gaseous atoms from three alkali halide surfaces (LiF, NaCl, GI)was studied to understand mechanical energy transfer in unreactive systems. The dynamics of the chemical reaction in the scattering of H(D) atoms from the surfaces of LIF(001) and the basal plane of graphite were also studied.

  13. Reactive Distillation for Esterification of Bio-based Organic Acids

    SciTech Connect (OSTI)

    Fields, Nathan; Miller, Dennis J.; Asthana, Navinchandra S.; Kolah, Aspi K.; Vu, Dung; Lira, Carl T.

    2008-09-23T23:59:59.000Z

    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.

  14. Options for Control of Reactive Power by Distributed Photovoltaic Generators

    E-Print Network [OSTI]

    Petr Sulc; Konstantin Turitsyn; Scott Backhaus; Michael Chertkov

    2010-08-04T23:59:59.000Z

    High penetration levels of distributed photovoltaic(PV) generation on an electrical distribution circuit present several challenges and opportunities for distribution utilities. Rapidly varying irradiance conditions may cause voltage sags and swells that cannot be compensated by slowly responding utility equipment resulting in a degradation of power quality. Although not permitted under current standards for interconnection of distributed generation, fast-reacting, VAR-capable PV inverters may provide the necessary reactive power injection or consumption to maintain voltage regulation under difficult transient conditions. As side benefit, the control of reactive power injection at each PV inverter provides an opportunity and a new tool for distribution utilities to optimize the performance of distribution circuits, e.g. by minimizing thermal losses. We discuss and compare via simulation various design options for control systems to manage the reactive power generated by these inverters. An important design decision that weighs on the speed and quality of communication required is whether the control should be centralized or distributed (i.e. local). In general, we find that local control schemes are capable for maintaining voltage within acceptable bounds. We consider the benefits of choosing different local variables on which to control and how the control system can be continuously tuned between robust voltage control, suitable for daytime operation when circuit conditions can change rapidly, and loss minimization better suited for nighttime operation.

  15. Reactivity accidents: A reassessment of the design-basis events

    SciTech Connect (OSTI)

    Diamond, D.J.; Hsu, Chia-Jung; Fitzpatrick, R.; Mirkovic, D.

    1989-01-01T23:59:59.000Z

    This paper summarizes a study of light water reactor event sequences which have been investigated for their potential to result in reactivity accidents with severe consequences. The study is an outgrowth of the concern which arose after the accident at Chernobyl and was recommended by the report of the US Nuclear Regulatory Commission (NRC) on the implications of that accident (NUREG-1251). The work was done for the NRC to reconfirm or bring into question previous judgments on reactivity events which must be analyzed for licensing. Event sequences were defined and then a probabilistic assessment was completed to estimate the frequency of the reactivity event and/or a deterministic calculation was completed to estimate the consequences to the fuel. Using the results of this analysis, analysis done by others, and a set of screening criteria developed within this study, judgments were made for each sequence as to its importance, and recommendations were made as to whether the NRC ought to be considering the important sequences as part of the design basis or for further, more detailed, investigation. 31 refs., 9 figs., 1 tab.

  16. Nitrogen stabilized reactive sputtering of optimized TiO{sub 2-x} photocatalysts with visible light reactivity

    SciTech Connect (OSTI)

    Chen, Le; Graham, Michael E.; Gray, Kimberly A. [Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois 60208 (United States)

    2009-07-15T23:59:59.000Z

    Photoreactive and visible light responsive nonstoichiometric mixed-phase titania was prepared by reactive direct current magnetron sputtering. Trace amounts of nitrogen were added for process stabilization without being incorporated into the films. Based on the CO{sub 2} photoreduction tests and structural and optical characterization, the influence of the trace nitrogen on the sputtered nonstoichiometric TiO{sub 2} was studied and was compared to nitrogen-doped titania.

  17. Gas-solid carbonation of Ca(OH)2 and CaO particles under non-isothermal and isothermal conditions by using a thermogravimetric analyzer

    E-Print Network [OSTI]

    Boyer, Edmond

    by using a thermogravimetric analyzer: Implications for CO2 capture G. Montes-Hernandeza, *, R. Chiriacb-solid carbonation of alkaline sorbents has been actively investigated as an alternative method to CO2 capture from industrial combustion sources and CO2 contained in the air. This study has a two-fold objective: firstly

  18. Effectiveness of organoclays as compatibilizers for multiphase polymer blends – A sustainable route for the mechanical recycling of co-mingled plastics

    SciTech Connect (OSTI)

    Causa, Andrea; Acierno, Domenico; Filippone, Giovanni [Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Piazzale V. Tecchio, 80, 80125 Napoli (Italy); Mistretta, Maria Chiara [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, Viale delle Scienze, ed. 6, 90128 Palermo (Italy)

    2014-05-15T23:59:59.000Z

    We prepare and characterize multiphase systems in which small amounts of recycled polymer, namely polyethylene terephtalate (PET) ground from waste bottles, are dispersed in a co-continuous blend of high-density polyethylene (HDPE) and polypropylene (PP). Some of such ternary systems are also filled with plate-like clay nanoparticles with different polarities, in order to assess their influence on the morphology and mechanical behaviour of the blends. On the basis of preliminary wettability considerations and inspections by means of scanning electron microscopy (SEM), the PET is found to preferentially locate within the PP phase. Such a positioning is desirable in order to minimize the presence of multiple interfaces, which is one of the major issues in the recycling process of co-mingles plastics. By means of SEM, dynamic-mechanical analysis and tensile tests we show that the addition of a filler with low polarity, which locates at the PET-matrix interface, has relevant implications on the structure and properties of the ternary systems, refining their morphology at the micro-scale and enhancing their high-temperature mechanical behaviour.

  19. Standard test methods for determining chemical durability of nuclear, hazardous, and mixed waste glasses and multiphase glass ceramics: The product consistency test (PCT)

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2002-01-01T23:59:59.000Z

    1.1 These product consistency test methods A and B evaluate the chemical durability of homogeneous glasses, phase separated glasses, devitrified glasses, glass ceramics, and/or multiphase glass ceramic waste forms hereafter collectively referred to as “glass waste forms” by measuring the concentrations of the chemical species released to a test solution. 1.1.1 Test Method A is a seven-day chemical durability test performed at 90 ± 2°C in a leachant of ASTM-Type I water. The test method is static and conducted in stainless steel vessels. Test Method A can specifically be used to evaluate whether the chemical durability and elemental release characteristics of nuclear, hazardous, and mixed glass waste forms have been consistently controlled during production. This test method is applicable to radioactive and simulated glass waste forms as defined above. 1.1.2 Test Method B is a durability test that allows testing at various test durations, test temperatures, mesh size, mass of sample, leachant volume, a...

  20. Anisotropic flow and flow fluctuations for Au + Au at $\\sqrt{s_{NN}}$ = 200 GeV in a multiphase transport model

    E-Print Network [OSTI]

    L. Ma; G. L. Ma; Y. G. Ma

    2014-04-23T23:59:59.000Z

    Anisotropic flow coefficients and their fluctuations are investigated for Au+Au collisions at center of mass energy $\\sqrt{s_{NN}}$ = 200 GeV by using a multi-phase transport model with string melting scenario. Experimental results of azimuthal anisotropies by means of the two- and four-particle cumulants are generally well reproduced by the model including both parton cascade and hadronic rescatterings. Event-by-event treatments of the harmonic flow coefficients $v_n$ (for n = 2, 3 and 4) are performed, in which event distributions of $v_n$ for different orders are consistent with Gaussian shapes over all centrality bins. Systematic studies on centrality, transverse momentum ($p_{T}$) and pseudo-rapidity ($\\eta$) dependencies of anisotropic flows and quantitative estimations of the flow fluctuations are presented. The $p_{T}$ and $\\eta$ dependencies of absolute fluctuations for both $v_2$ and $v_3$ follow similar trends as their flow coefficients. Relative fluctuation of triangular flow $v_3$ is slightly centrality-dependent, which is quite different from that of elliptic flow $v_2$. It is observed that parton cascade has a large effect on the flow fluctuations, but hadronic scatterings make little contribution to the flow fluctuations, which indicates flow fluctuations are mainly modified during partonic evolution stage.

  1. Azimuthal anisotropies of reconstructed jets in Pb+Pb collisions at $\\sqrt{s_{_{\\rm NN}}}$ = 2.76 TeV in a multiphase transport model

    E-Print Network [OSTI]

    Mao-Wu Nie; Guo-Liang Ma

    2014-07-28T23:59:59.000Z

    Azimuthal anisotropies of reconstructed jets [$v_{n}^{jet} (n=2, 3)$] have been investigated in Pb+Pb collisions at the center of mass energy $\\sqrt{s_{_{\\rm NN}}}$ = 2.76 TeV within a framework of a multiphase transport (AMPT) model. The $v_{2}^{jet}$ is in good agreement with the recent ATLAS data. However, the $v_{3}^{jet}$ shows a smaller magnitude than $v_{2}^{jet}$, and approaches zero at a larger transverse momentum. It is attributed to the path-length dependence in which the jet energy loss fraction depends on the azimuthal angles with respect to different orders of event planes. The ratio $v_{n}^{jet}/\\varepsilon_{n}$ increases from peripheral to noncentral collisions, and $v_{n}^{jet}$ increases with the initial spatial asymmetry ($\\varepsilon_{n}$) for a given centrality bin. These behaviors indicate that the $v_{n}^{jet}$ is produced by the strong interactions between jet and the partonic medium with different initial geometry shapes. Therefore, azimuthal anisotropies of reconstructed jet are proposed as a good probe to study the initial spatial fluctuations, which are expected to provide constraints on the path-length dependence of jet quenching models.

  2. Survey of Reactive Power Planning Methods Wenjuan Zhang, Student Member, IEEE, Leon M. Tolbert, Senior Member, IEEE

    E-Print Network [OSTI]

    Tolbert, Leon M.

    Survey of Reactive Power Planning Methods Wenjuan Zhang, Student Member, IEEE, Leon M. Tolbert, Senior Member, IEEE Abstract Reactive power planning (RPP) involves optimal allocation and determination to solve the RPP problem. Index Terms -- reactive power planning, reactive power optimization, optimal

  3. Transportation of a 40-year-old reactive mixed waste

    SciTech Connect (OSTI)

    Dietz, C.G. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1996-12-31T23:59:59.000Z

    Now a national landmark, Experimental Breeder Reactor-I was the worlds first nuclear reactor to produce a usable amount of commercial electricity in 1951. It is located on the Arco desert in Eastern Idaho at the Idaho National Engineering Laboratory (INEL). In 1955, the reactor experienced a cooling accident that resulted in core damage and a partial meltdown of the reactor, which left a serious cleanup challenge that had not been addressed until recently. The EBR-I reactor used liquid metal sodium-potassium (NaK) as a coolant because it is eutectic; that is, it remains a liquid at the lowest possible temperature and was a very effective coolant. NaK looks very much like mercury out of a thermometer. However, NaK is reactive and will burn in the presence of air (absorbing moisture from it) and is extremely reactive in direct contact with water, producing hydrogen. Furthermore, this highly reactive coolant was radioactively contaminated from the accident. Most of the radioactively contaminated NaK was processed and disposed of in 1955. However, approximately 180 gal of residual contaminated NaK remained because of the possibility it contained 10 1-gram foils of plutonium, which were in the reactor core at the time of the meltdown. This NaK was stored in four containers: two 55-gallon stainless steel transportation drums, one 60-gallon carbon steel container (used as a transfer vessel), and one 10-gallon carbon steel container (used to store radioactively contaminated water). This paper describes the transport of this waste from its temporary storage bunker to Argonne National Laboratory West for final treatment and preparation for disposal.

  4. Gas sampling system for reactive gas-solid mixtures

    DOE Patents [OSTI]

    Daum, Edward D. (Alliance, OH); Downs, William (Alliance, OH); Jankura, Bryan J. (Mogadore, OH); McCoury, Jr., John M. (Mineral City, OH)

    1990-01-01T23:59:59.000Z

    An apparatus and method for sampling gas containing a reactive particulate solid phase flowing through a duct and for communicating a representative sample to a gas analyzer. A sample probe sheath 32 with an angular opening 34 extends vertically into a sample gas duct 30. The angular opening 34 is opposite the gas flow. A gas sampling probe 36 concentrically located within sheath 32 along with calibration probe 40 partly extends in the sheath 32. Calibration probe 40 extends further in the sheath 32 than gas sampling probe 36 for purging the probe sheath area with a calibration gas during calibration.

  5. Gas sampling system for reactive gas-solid mixtures

    DOE Patents [OSTI]

    Daum, Edward D. (Alliance, OH); Downs, William (Alliance, OH); Jankura, Bryan J. (Mogadore, OH); McCoury, Jr., John M. (Mineral City, OH)

    1989-01-01T23:59:59.000Z

    An apparatus and method for sampling a gas containing a reactive particulate solid phase flowing through a duct and for communicating a representative sample to a gas analyzer. A sample probe sheath 32 with an angular opening 34 extends vertically into a sample gas duct 30. The angular opening 34 is opposite the gas flow. A gas sampling probe 36 concentrically located within sheath 32 along with calibration probe 40 partly extend in the sheath 32. Calibration probe 40 extends further in the sheath 32 than gas sampling probe 36 for purging the probe sheath area with a calibration gas during calibration.

  6. Method for preparing hydride configurations and reactive metal surfaces

    DOE Patents [OSTI]

    Silver, Gary L. (Centerville, OH)

    1988-08-16T23:59:59.000Z

    A method for preparing highly hydrogen-reactive surfaces on metals which normally require substantial heating, high pressures, or an extended induction period, which involves pretreatment of said surfaces with either a non-oxidizing acid or hydrogen gas to form a hydrogen-bearing coating on said surfaces, and subsequently heating said coated metal in the absence of moisture and oxygen for a period sufficient to decompose said coating and cooling said metal to room temperature. Surfaces so treated will react almost instantaneously with hydrogen gas at room temperature and low pressure. The method is particularly applicable to uranium, thorium, and lanthanide metals.

  7. Reactive sticking coefficients for silane and disilane on polycrystalline silicon

    SciTech Connect (OSTI)

    Buss, R.J.; Ho, P.; Breiland, W.G.; Coltrin, M.E.

    1988-04-15T23:59:59.000Z

    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 nonlinear Arrhenius temperature dependencies and decrease with increasing flux at low (710 /sup 0/C) temperatures. Several simple models are proposed to explain these observations. The results are compared with previous studies of the SiH/sub 4//Si(s) reaction and low-pressure chemical vapor deposition-rate measurements.

  8. Low Reactivity SI Engine Lubricant Program | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetterEconomy andTerms LoanLos AngelesGuillermo10Reactivity SI

  9. DOE - Office of Legacy Management -- Reactive Metals Inc - OH 10

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling Corp -K Le Blond Machine Tool Co -Reactive

  10. Hybrid nuclear reactor grey rod to obtain required reactivity worth

    DOE Patents [OSTI]

    Miller, John V. (Munhall, PA); Carlson, William R. (Scott Township, Allegheny County, PA); Yarbrough, Michael B. (Hempfield Township, Westmoreland County, PA)

    1991-01-01T23:59:59.000Z

    Hybrid nuclear reactor grey rods are described, wherein geometric combinations of relatively weak neutron absorber materials such as stainless steel, zirconium or INCONEL, and relatively strong neutron absorber materials, such as hafnium, silver-indium cadmium and boron carbide, are used to obtain the reactivity worths required to reach zero boron change load follow. One embodiment includes a grey rod which has combinations of weak and strong neutron absorber pellets in a stainless steel cladding. The respective pellets can be of differing heights. A second embodiment includes a grey rod with a relatively thick stainless steel cladding receiving relatively strong neutron absorber pellets only. A third embodiment includes annular relatively weak netron absorber pellets with a smaller diameter pellet of relatively strong absorber material contained within the aperture of each relatively weak absorber pellet. The fourth embodiment includes pellets made of a homogeneous alloy of hafnium and a relatively weak absorber material, with the percentage of hafnium chosen to obtain the desired reactivity worth.

  11. Reactive-coupling-induced normal mode splittings in microdisk resonators coupled to waveguides

    SciTech Connect (OSTI)

    Huang Sumei; Agarwal, G. S. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)

    2010-05-15T23:59:59.000Z

    We study the optomechanical design introduced by M. Li et al. [Phys. Rev. Lett. 103, 223901 (2009)], which is very effective for investigation of the effects of reactive coupling. We show the normal mode splitting that is due solely to reactive coupling rather than due to dispersive coupling. We suggest feeding the waveguide with a pump field along with a probe field and scanning the output probe for evidence of reactive-coupling-induced normal mode splitting.

  12. Rat colonic reactive oxygen species production and DNA damage are mediated by diet and age

    E-Print Network [OSTI]

    Henderson, Cara Aletha Everett

    2001-01-01T23:59:59.000Z

    diacetate docosahexanoic acid diphenyliodonium chloride ethylenediaminetetraacetic acid eicosapentanoic acid ethidium homodiner ? 1 fragment length analysis using repair enzymes Fapy glycosylase Hanks' balanced salt solution hydrogen peroxide lipid... the elimination of cancer cells. Production and Functions of Reactive Oxygen Species Formation of reactive oxygen species Reactive oxygen species are a by-product of normal metabolism and include superoxide (Ot' ), hydrogen peroxide (HzO&), and the hydroxyl...

  13. Composite Materials for Hazard Mitigation of Reactive Metal Hydrides.

    SciTech Connect (OSTI)

    Pratt, Joseph William; Cordaro, Joseph Gabriel; Sartor, George B.; Dedrick, Daniel E.; Reeder, Craig L.

    2012-02-01T23:59:59.000Z

    In an attempt to mitigate the hazards associated with storing large quantities of reactive metal hydrides, polymer composite materials were synthesized and tested under simulated usage and accident conditions. The composites were made by polymerizing vinyl monomers using free-radical polymerization chemistry, in the presence of the metal hydride. Composites with vinyl-containing siloxane oligomers were also polymerized with and without added styrene and divinyl benzene. Hydrogen capacity measurements revealed that addition of the polymer to the metal hydride reduced the inherent hydrogen storage capacity of the material. The composites were found to be initially effective at reducing the amount of heat released during oxidation. However, upon cycling the composites, the mitigating behavior was lost. While the polymer composites we investigated have mitigating potential and are physically robust, they undergo a chemical change upon cycling that makes them subsequently ineffective at mitigating heat release upon oxidation of the metal hydride. Acknowledgements The authors would like to thank the following people who participated in this project: Ned Stetson (U.S. Department of Energy) for sponsorship and support of the project. Ken Stewart (Sandia) for building the flow-through calorimeter and cycling test stations. Isidro Ruvalcaba, Jr. (Sandia) for qualitative experiments on the interaction of sodium alanate with water. Terry Johnson (Sandia) for sharing his expertise and knowledge of metal hydrides, and sodium alanate in particular. Marcina Moreno (Sandia) for programmatic assistance. John Khalil (United Technologies Research Corp) for insight into the hazards of reactive metal hydrides and real-world accident scenario experiments. Summary In an attempt to mitigate and/or manage hazards associated with storing bulk quantities of reactive metal hydrides, polymer composite materials (a mixture of a mitigating polymer and a metal hydride) were synthesized and tested under simulated usage and accident conditions. Mitigating the hazards associated with reactive metal hydrides during an accident while finding a way to keep the original capability of the active material intact during normal use has been the focus of this work. These composites were made by polymerizing vinyl monomers using free-radical polymerization chemistry, in the presence of the metal hydride, in this case a prepared sodium alanate (chosen as a representative reactive metal hydride). It was found that the polymerization of styrene and divinyl benzene could be initiated using AIBN in toluene at 70 degC. The resulting composite materials can be either hard or brittle solids depending on the cross-linking density. Thermal decomposition of these styrene-based composite materials is lower than neat polystyrene indicating that the chemical nature of the polymer is affected by the formation of the composite. The char-forming nature of cross-linked polystyrene is low and therefore, not an ideal polymer for hazard mitigation. To obtain composite materials containing a polymer with higher char-forming potential, siloxane-based monomers were investigated. Four vinyl-containing siloxane oligomers were polymerized with and without added styrene and divinyl benzene. Like the styrene materials, these composite materials exhibited thermal decomposition behavior significantly different than the neat polymers. Specifically, the thermal decomposition temperature was shifted approximately 100 degC lower than the neat polymer signifying a major chemical change to the polymer network. Thermal analysis of the cycled samples was performed on the siloxane-based composite materials. It was found that after 30 cycles the siloxane-containing polymer composite material has similar TGA/DSC-MS traces as the virgin composite material indicating that the polymer is physically intact upon cycling. Hydrogen capacity measurements revealed that addition of the polymer to the metal hydride in the form of a composite material reduced the inherent hydrogen storage capacity of the material. This

  14. Atomic-level studies of the depletion in reactive sites during...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    weathering, the atomic-level “reactive sites” on the surfaces of minerals must be characterized and quantified. Whether these sites are atomic in nature,...

  15. Effect of different intravenous iron preparations on lymphocyte intracellular reactive oxygen species generation and subpopulation survival.

    E-Print Network [OSTI]

    Gupta, Ajay; Zhuo, Jiaying; Zha, Junli; Reddy, Srinivasa; Olp, Jonathan; Pai, Amy

    2010-01-01T23:59:59.000Z

    IV iron compounds induced greater intracellular ROS generation,IV iron preparations on intracellular reactive oxygen species generationIV iron preparations on intracellular immune cell ROS generation

  16. Influence of Mg2+ on CaCO3 precipitation during subsurface reactive...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    subsurface reactive transport in a homogeneous silicon-etched pore network. Abstract: Calcium carbonate (CaCO3) geochemical reactions exert a fundamental control on the...

  17. KINETIC MODELING OF A FISCHER-TROPSCH REACTION OVER A COBALT CATALYST IN A SLURRY BUBBLE COLUMN REACTOR FOR INCORPORATION INTO A COMPUTATIONAL MULTIPHASE FLUID DYNAMICS MODEL

    SciTech Connect (OSTI)

    Anastasia Gribik; Doona Guillen, PhD; Daniel Ginosar, PhD

    2008-09-01T23:59:59.000Z

    Currently multi-tubular fixed bed reactors, fluidized bed reactors, and slurry bubble column reactors (SBCRs) are used in commercial Fischer Tropsch (FT) synthesis. There are a number of advantages of the SBCR compared to fixed and fluidized bed reactors. The main advantage of the SBCR is that temperature control and heat recovery are more easily achieved. The SBCR is a multiphase chemical reactor where a synthesis gas, comprised mainly of H2 and CO, is bubbled through a liquid hydrocarbon wax containing solid catalyst particles to produce specialty chemicals, lubricants, or fuels. The FT synthesis reaction is the polymerization of methylene groups [-(CH2)-] forming mainly linear alkanes and alkenes, ranging from methane to high molecular weight waxes. The Idaho National Laboratory is developing a computational multiphase fluid dynamics (CMFD) model of the FT process in a SBCR. This paper discusses the incorporation of absorption and reaction kinetics into the current hydrodynamic model. A phased approach for incorporation of the reaction kinetics into a CMFD model is presented here. Initially, a simple kinetic model is coupled to the hydrodynamic model, with increasing levels of complexity added in stages. The first phase of the model includes incorporation of the absorption of gas species from both large and small bubbles into the bulk liquid phase. The driving force for the gas across the gas liquid interface into the bulk liquid is dependent upon the interfacial gas concentration in both small and large bubbles. However, because it is difficult to measure the concentration at the gas-liquid interface, coefficients for convective mass transfer have been developed for the overall driving force between the bulk concentrations in the gas and liquid phases. It is assumed that there are no temperature effects from mass transfer of the gas phases to the bulk liquid phase, since there are only small amounts of dissolved gas in the liquid phase. The product from the incorporation of absorption is the steady state concentration profile of the absorbed gas species in the bulk liquid phase. The second phase of the model incorporates a simplified macrokinetic model to the mass balance equation in the CMFD code. Initially, the model assumes that the catalyst particles are sufficiently small such that external and internal mass and heat transfer are not rate limiting. The model is developed utilizing the macrokinetic rate expression developed by Yates and Satterfield (1991). Initially, the model assumes that the only species formed other than water in the FT reaction is C27H56. Change in moles of the reacting species and the resulting temperature of the catalyst and fluid phases is solved simultaneously. The macrokinetic model is solved in conjunction with the species transport equations in a separate module which is incorporated into the CMFD code.

  18. Multi-phase glass-ceramics as a waste form for combined fission products: alkalis, alkaline earths, lanthanides, and transition metals

    SciTech Connect (OSTI)

    Crum, Jarrod V.; Turo, Laura A.; Riley, Brian J.; Tang, Ming; Kossoy, Anna

    2012-04-01T23:59:59.000Z

    In this study, multi-phase silicate-based glass-ceramics were investigated as an alternate waste form for immobilizing non-fissionable products from used nuclear fuel. Currently, borosilicate glass is the waste form selected for immobilization of this waste stream, however, the low thermal stability and solubility of MoO{sub 3} in borosilicate glass translates into a maximum waste loading in the range of 15-20 mass%. Glass-ceramics provide the opportunity to target durable crystalline phases, e.g., powellite, oxyapatite, celsian, and pollucite, that will incorporate MoO{sub 3} as well as other waste components such as lanthanides, alkalis, and alkaline earths at levels 2X the solubility limits of a single-phase glass. In addition a glass-ceramic could provide higher thermal stability, depending upon the properties of the crystalline and amorphous phases. Glass-ceramics were successfully synthesized at waste loadings of 42, 45, and 50 mass% with the following glass additives: B{sub 2}O{sub 3}, Al{sub 2}O{sub 3}, CaO and SiO{sub 2} by slow cooling form from a glass melt. Glass-ceramics were characterized in terms of phase assemblage, morphology, and thermal stability. The targeted phases: powellite and oxyapatite were observed in all of the compositions along with a lanthanide borosilicate, and cerianite. Results of this initial investigation of glass-ceramics show promise as a potential waste form to replace single-phase borosilicate glass.

  19. Initiating the Validation of CCIM Processability for Multi-phase all Ceramic (SYNROC) HLW Form: Plan for Test BFY14CCIM-C

    SciTech Connect (OSTI)

    Vince Maio

    2014-08-01T23:59:59.000Z

    This plan covers test BFY14CCIM-C which will be a first–of–its-kind demonstration for the complete non-radioactive surrogate production of multi-phase ceramic (SYNROC) High Level Waste Forms (HLW) using Cold Crucible Induction Melting (CCIM) Technology. The test will occur in the Idaho National Laboratory’s (INL) CCIM Pilot Plant and is tentatively scheduled for the week of September 15, 2014. The purpose of the test is to begin collecting qualitative data for validating the ceramic HLW form processability advantages using CCIM technology- as opposed to existing ceramic–lined Joule Heated Melters (JHM) currently producing BSG HLW forms. The major objectives of BFY14CCIM-C are to complete crystalline melt initiation with a new joule-heated resistive starter ring, sustain inductive melting at temperatures between 1600 to 1700°C for two different relatively high conductive materials representative of the SYNROC ceramic formation inclusive of a HLW surrogate, complete melter tapping and pouring of molten ceramic material in to a preheated 4 inch graphite canister and a similar canister at room temperature. Other goals include assessing the performance of a new crucible specially designed to accommodate the tapping and pouring of pure crystalline forms in contrast to less recalcitrant amorphous glass, assessing the overall operational effectiveness of melt initiation using a resistive starter ring with a dedicated power source, and observing the tapped molten flow and subsequent relatively quick crystallization behavior in pans with areas identical to standard HLW disposal canisters. Surrogate waste compositions with ceramic SYNROC forming additives and their measured properties for inductive melting, testing parameters, pre-test conditions and modifications, data collection requirements, and sampling/post-demonstration analysis requirements for the produced forms are provided and defined.

  20. Anode reactive bleed and injector shift control strategy

    DOE Patents [OSTI]

    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

    2012-01-03T23:59:59.000Z

    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.

  1. Distributed control for optimal reactive power compensation in smart microgrids

    E-Print Network [OSTI]

    Bolognani, Saverio

    2011-01-01T23:59:59.000Z

    We consider the problem of optimal reactive power compensation for the minimization of power distribution losses in a smart microgrid. We first propose an approximate model for the power distribution network, which allows us to cast the problem into the class of convex quadratic, linearly constrained, optimization problems. We also show how this model provides the tools for a distributed approach, in which agents have a partial knowledge of the problem parameters and state, and can only perform local measurements. Then, we design a randomized, gossip-like optimization algorithm, providing conditions for convergence together with an analytic characterization of the convergence speed. The analysis shows that the best performance can be achieved when we command cooperation among agents that are neighbors in the smart microgrid topology. Numerical simulations are included to validate the proposed model and to confirm the analytic results about the performance of the proposed algorithm.

  2. Advanced hydraulic fracturing methods to create in situ reactive barriers

    SciTech Connect (OSTI)

    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

    1997-12-31T23:59:59.000Z

    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.

  3. Method of measuring reactive acoustic power density in a fluid

    DOE Patents [OSTI]

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1985-09-03T23:59:59.000Z

    A method for determining reactive acoustic power density level and its direction in a fluid using a single sensor is disclosed. In the preferred embodiment, an apparatus for conducting the method, which is termed a thermoacoustic couple, consists of a stack of thin, spaced apart polymeric plates, selected ones of which include multiple bimetallic thermocouple junctions positioned along opposite end edges thereof. The thermocouple junctions are connected in series in the nature of a thermopile, and are arranged so as to be responsive to small temperature differences between the opposite edges of the plates. The magnitude of the temperature difference, as represented by the magnitude of the electrical potential difference generated by the thermopile, is found to be directly related to the level of acoustic power density in the gas. 5 figs.

  4. Method of measuring reactive acoustic power density in a fluid

    DOE Patents [OSTI]

    Wheatley, John C. (Los Alamos, NM); Swift, Gregory W. (Los Alamos, NM); Migliori, Albert (Santa Fe, NM)

    1985-01-01T23:59:59.000Z

    A method for determining reactive acoustic power density level and its direction in a fluid using a single sensor is disclosed. In the preferred embodiment, an apparatus for conducting the method, which is termed a thermoacoustic couple, consists of a stack of thin, spaced apart polymeric plates, selected ones of which include multiple bimetallic thermocouple junctions positioned along opposite end edges thereof. The thermocouple junctions are connected in series in the nature of a thermopile, and are arranged so as to be responsive to small temperature differences between the opposite edges of the plates. The magnitude of the temperature difference, as represented by the magnitude of the electrical potential difference generated by the thermopile, is found to be directly related to the level of acoustic power density in the gas.

  5. Properties of Reactive Oxygen Species by Quantum Monte Carlo

    E-Print Network [OSTI]

    Andrea Zen; Bernhardt L. Trout; Leonardo Guidoni

    2014-06-16T23:59:59.000Z

    The electronic properties of the oxygen molecule, in its singlet and triplet states, and of many small oxygen-containing radicals and anions have important roles in different fields of Chemistry, Biology and Atmospheric Science. Nevertheless, the electronic structure of such species is a challenge for ab-initio computational approaches because of the difficulties to correctly describe the statical and dynamical correlation effects in presence of one or more unpaired electrons. Only the highest-level quantum chemical approaches can yield reliable characterizations of their molecular properties, such as binding energies, equilibrium structures, molecular vibrations, charge distribution and polarizabilities. In this work we use the variational Monte Carlo (VMC) and the lattice regularized Monte Carlo (LRDMC) methods to investigate the equilibrium geometries and molecular properties of oxygen and oxygen reactive species. Quantum Monte Carlo methods are used in combination with the Jastrow Antisymmetrized Geminal Power (JAGP) wave function ansatz, which has been recently shown to effectively describe the statical and dynamical correlation of different molecular systems. In particular we have studied the oxygen molecule, the superoxide anion, the nitric oxide radical and anion, the hydroxyl and hydroperoxyl radicals and their corresponding anions, and the hydrotrioxyl radical. Overall, the methodology was able to correctly describe the geometrical and electronic properties of these systems, through compact but fully-optimised basis sets and with a computational cost which scales as $N^3-N^4$, where $N$ is the number of electrons. This work is therefore opening the way to the accurate study of the energetics and of the reactivity of large and complex oxygen species by first principles.

  6. Abstract--This paper proposes a two-level framework for the operation of a competitive market for reactive power ancillary

    E-Print Network [OSTI]

    Cañizares, Claudio A.

    and the selected reactive power service providers. Index Terms- System operation, ancillary services, electricity reactive power provisions in the context of deregulated electricity markets, namely, reactive power for reactive power ancillary services. It is argued that the first-level, i.e. reactive power procurement

  7. A transport based one-dimensional perturbation code for reactivity calculations in metal systems

    SciTech Connect (OSTI)

    Wenz, T.R.

    1995-02-01T23:59:59.000Z

    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.

  8. Comparison of Alternative Control Structures for an Ideal Two-Product Reactive Distillation Column

    E-Print Network [OSTI]

    Al-Arfaj, Muhammad A.

    Comparison of Alternative Control Structures for an Ideal Two-Product Reactive Distillation Column distillation columns have been explored in many papers, very few papers have dealt with closed-loop control. Most of these control papers consider reactive distillation columns in which there is only one product

  9. Design of Extraction Column Methanol Recovery System for the TAME Reactive Distillation Process

    E-Print Network [OSTI]

    Al-Arfaj, Muhammad A.

    Design of Extraction Column Methanol Recovery System for the TAME Reactive Distillation Process system for TAME reactive distillation process using extraction column with water as a solvent. The design distillation column which was optimized to recover methanol and recycle water to the extraction column. Other

  10. Analytical solutions for sequentially coupled one-dimensional reactive transport problems Part II: Special cases,

    E-Print Network [OSTI]

    Clement, Prabhakar

    Analytical solutions for sequentially coupled one-dimensional reactive transport problems ­ Part II solutions to multi-species reactive transport equations coupled through sorption and sequential first special-case transport scenarios involving zero initial condition, identical retardation factors and zero

  11. A gas-kinetic scheme for reactive ows Yongsheng Lian, Kun Xu*

    E-Print Network [OSTI]

    Xu, Kun

    A gas-kinetic scheme for reactive ¯ows Yongsheng Lian, Kun Xu* Department of Mathematics, Hong Kong in revised form 22 July 1999; accepted 22 July 1999 Abstract In this paper, the gas-kinetic BGK scheme for the compressible ¯ow equations is extended to chemical reactive ¯ow. The mass fraction of the unburnt gas

  12. Comparison of reactivity measurements using water height, rods, and boron poison in the CX-SNTP

    SciTech Connect (OSTI)

    Ball, R.M. [B& W Nuclear Environmental Services, Inc., Lynchburg, VA (United States); Hoovler, G.S. [Babcock & Wilcox, Lynchburg, VA (United States)

    1995-12-31T23:59:59.000Z

    Babcock & Wilcox (B&W) designed and fabricated the experimental nuclear reactor (CX), for the Space Nuclear Thermal Propulsion (SNTP) program sponsored by the U.S. Air Force. The CX had an excess reactivity between $2.0 and $2.5. Variations in differential boric acid worth depending on the method used for balancing the reactivity are discussed in this paper.

  13. Synthesis, Characterization and Reactivity of Electrophilic Organometallic Compounds of Ruthenium, Tantalum and Silicon

    E-Print Network [OSTI]

    Ramirez, Rodrigo

    2014-12-11T23:59:59.000Z

    SYNTHESIS, CHARACTERIZATION AND REACTIVITY OF ELECTROPHILIC ORGANOMETALLIC COMPOUNDS OF RUTHENIUM, TANTALUM AND SILICON A Dissertation by RODRIGO RAMIREZ Submitted to the Office of Graduate and Professional Studies of Texas A... December 2014 Major Subject: Chemistry Copyright 2014 Rodrigo Ramírez ii ABSTRACT The work presented herein will discuss the synthesis, characterization and reactivity of electrophilic organometallic compounds of ruthenium, tantalum...

  14. PEV-based Reactive Power Compensation for Wind DG Units: A Stackelberg Game Approach

    E-Print Network [OSTI]

    Mohsenian-Rad, Hamed

    balancing supply and demand for active power, we also need to compensate reactive power for each wind DGPEV-based Reactive Power Compensation for Wind DG Units: A Stackelberg Game Approach Chenye Wu, in particular wind power, in form of distributed generation (DG) units. However, one important challenge

  15. PEV-based Reactive Power Compensation for Wind DG Units: A Stackelberg Game Approach

    E-Print Network [OSTI]

    Huang, Jianwei

    balancing supply and demand for active power, we also need to compensate reactive power for each wind DG1 PEV-based Reactive Power Compensation for Wind DG Units: A Stackelberg Game Approach Chenye Wu, in particular wind power, in form of distributed generation (DG) units. However, one important challenge

  16. Learning Reactive Neurocontrollers using Simulated Annealing for Mobile Philippe Lucidarme, Alain Ligeois

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Learning Reactive Neurocontrollers using Simulated Annealing for Mobile Robots Philippe Lucidarme a method based on simulated annealing to learn reactive behaviors. This work is related with multi is a neural network and we use a simulated annealing techniques to learn the synaptic weights. We'll first

  17. Intelligent Voltage and Reactive Power Control of Mini-Hydro Power Stations for Maximisation of Real

    E-Print Network [OSTI]

    Harrison, Gareth

    1 Intelligent Voltage and Reactive Power Control of Mini-Hydro Power Stations for Maximisation Control (APFC) modes. The ability to export active and reactive power from mini-hydro power generators electrical power generation from renewable resources. Additionally, the potential early retiral of central

  18. ORNL/TM-2008/083 A Tariff for Reactive Power

    E-Print Network [OSTI]

    Pennycook, Steve

    ORNL/TM-2008/083 A Tariff for Reactive Power 2008 Prepared by Christopher Tufon, Pacific Gas & Electric Company Alan G. Isemonger, California Independent System Operator Brendan Kirby, ORNL, Knowledge and Transportation Science Division A Tariff for Reactive Power Christopher Tufon Alan G. Isemonger Brendan Kirby

  19. Small Inverter-Interfaced Distributed Energy Resources for Reactive Power Support

    E-Print Network [OSTI]

    Liberzon, Daniel

    to provide reactive power support. I. INTRODUCTION Electrical generators connected to ac power grids mustSmall Inverter-Interfaced Distributed Energy Resources for Reactive Power Support Alejandro D. Dom´inguez-Garc´ia, Christoforos N. Hadjicostis, Philip T. Krein, and Stanton T. Cady Department of Electrical and Computer

  20. Specification and Design of Reactive Systems B.S. (National Chiao-Tung University) 1991

    E-Print Network [OSTI]

    of Reactive Systems by Bilung Lee Doctor of Philosophy in Engineering ­ Electrical Engineering and ComputerSpecification and Design of Reactive Systems by Bilung Lee B.S. (National Chiao-Tung University of the requirements for the degree of Doctor of Philosophy in Engineering ­ Electrical Engineering and Computer

  1. Parameters of Postocclusive Reactive Hyperemia Measured by Near Infrared Spectroscopy in Patients with Peripheral Vascular

    E-Print Network [OSTI]

    Ljubljana, University of

    Parameters of Postocclusive Reactive Hyperemia Measured by Near Infrared Spectroscopy in Patients PRESERN-STRUKELJ,2 and DAMIJAN MIKLAVC IC 1 1 University of Ljubljana, Faculty of Electrical Engineering study was to determine the parameters of the postocclusive reactive hyperemia test that could help

  2. IEEE TRANSACTIONS ON POWER SYSTEMS (ACCEPTED NOVEMBER 8, 2014) 1 Stochastic Reactive Power Management

    E-Print Network [OSTI]

    Giannakis, Georgios

    IEEE TRANSACTIONS ON POWER SYSTEMS (ACCEPTED NOVEMBER 8, 2014) 1 Stochastic Reactive Power response, and electric vehicles. Advances in photovoltaic (PV) inverters offer new opportunities for reactive power management provided PV owners have the right invest- ment incentives. In this context

  3. Intelligent Network-Layer Management for Wireless Mesh Networks: Dynamic Tuning of a Reactive Routing Protocol

    E-Print Network [OSTI]

    Kolner, Brian H.

    1 Intelligent Network-Layer Management for Wireless Mesh Networks: Dynamic Tuning of a Reactive Routing Protocol Dan Marconett, Minsoo Lee, Xiaohui Ye and S. J. Ben Yoo Dept. of Electrical and Computer learning to dynamically modify reactive routing protocol parameters in real-time, to better facilitate

  4. Automatic Testing of Reactive Systems \\Lambda Pascal Raymond, Xavier Nicollin, Nicolas Halbwachs y

    E-Print Network [OSTI]

    Halbwachs, Nicolas

    Automatic Testing of Reactive Systems \\Lambda Pascal Raymond, Xavier Nicollin, Nicolas Halbwachs y V'erimag z , Grenoble ­ France Daniel Weber x Schneider Electric, Grenoble ­ France Abstract This paper addresses the problem of automatizing the production of test sequences for reactive systems. We

  5. Stability of planar reactive fronts in external fields Arkady B. Rovinsky,* Anatol M. Zhabotinsky,

    E-Print Network [OSTI]

    Epstein, Irving R.

    in reactive systems due to external fields such as electric fields or pressure gradients, may significantlyStability of planar reactive fronts in external fields Arkady B. Rovinsky,* Anatol M. Zhabotinsky arise naturally in systems sub- jected to external fields, such as electric fields or pressure gradients

  6. European Wind Energy Conference 2007 Milan Measurement based analysis of active and reactive power

    E-Print Network [OSTI]

    European Wind Energy Conference 2007 ­ Milan 1 Measurement based analysis of active and reactive of the electricity is produced by wind turbines and combined heat and power plants (CHPs). Most of them are connected of reactive power between the 60 kV and the 150 kV networks. Further, the TSO is obligated to compensate

  7. MEASURING REACTIVE MARKET POWER Fernando L. Alvarado Thomas Overbye Peter Sauer

    E-Print Network [OSTI]

    MEASURING REACTIVE MARKET POWER Fernando L. Alvarado Thomas Overbye Peter Sauer The University-Hirschman Index) can be used to measure reactive power market concentration. The proposed method is illustrated by means of a simple example. Keywords: Electric power transmission, monopoly, mar- ket concentration. 1

  8. Rollable multicolor display using electrically induced blueshift of a cholesteric reactive mesogen mixture

    E-Print Network [OSTI]

    Wu, Shin-Tson

    Rollable multicolor display using electrically induced blueshift of a cholesteric reactive mesogen September 2006 Electrically controllable blueshift of the reflection band in a planar cholesteric reactive mesogen cell is observed. The responsible mechanism is electric-field-induced Helfrich deformation J. Chem

  9. PATHS: Analysis of PATH Duration Statistics and their Impact on Reactive MANET Routing Protocols

    E-Print Network [OSTI]

    Krishnamachari, Bhaskar

    PATHS: Analysis of PATH Duration Statistics and their Impact on Reactive MANET Routing Protocols Department of Electrical Engineering University of Southern California {narayans,fbai,bkrishna,helmy}@usc.edu ABSTRACT We develop a detailed approach to study how mobility im- pacts the performance of reactive MANET

  10. 39333939 ORNL/TM-2008/174 Local Dynamic Reactive Power for

    E-Print Network [OSTI]

    Pennycook, Steve

    39333939 ORNL/TM-2008/174 Local Dynamic Reactive Power for Correction of System Voltage Problems Local Dynamic Reactive Power for Correction of System Voltage Problems John D. Kueck* D. Tom Rizy Group at Oak Ridge National Laboratory Professor of Electrical Engineering at University of Tennessee

  11. Age-Related Differences in Emotional Reactivity, Regulation, and Rejection Sensitivity in Adolescence

    E-Print Network [OSTI]

    Ochsner, Kevin

    Age-Related Differences in Emotional Reactivity, Regulation, and Rejection Sensitivity Massachusetts Institute of Technology James J. Gross Stanford University Katherine A. Remy and Kevin N. Ochsner reactivity or emotion regulation. Study 1 addressed this question by presenting healthy individuals aged 10

  12. Concentrations and Snow-Atmosphere Fluxes of Reactive Nitrogen at Summit, Greenland

    E-Print Network [OSTI]

    1 Concentrations and Snow-Atmosphere Fluxes of Reactive Nitrogen at Summit, Greenland J. W. Munger AT SUMMIT, GREENLAND 2 Abstract. Concentrations and fluxes of NOy (total reactive nitrogen), ozone concentra at Summit, Greenland. Median NOy concentrations declined from 947 ppt in May to 444 ppt by July. NOy fluxes

  13. Lycopene cyclase paralog CruP protects against reactive oxygen species in oxygenic

    E-Print Network [OSTI]

    Wurtzel, Eleanore

    , quenching singlet oxygen generated during the water-splitting process of photo- synthesis (10, 11). VariousLycopene cyclase paralog CruP protects against reactive oxygen species in oxygenic photosynthetic cyclase. Instead, we show that CruP aids in preventing accumulation of reactive oxygen species (ROS

  14. Reactive power management of distribution networks with wind generation for improving voltage stability

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    -loadability Reactive power margin Wind turbine a b s t r a c t This paper proposes static and dynamic VAR planningReactive power management of distribution networks with wind generation for improving voltage February 2013 Available online Keywords: Composite load Distributed generation D-STATCOM Q

  15. Modeling Reactive Flows in Porous Media Peter Lichtner (lead PI), Los Alamos National Laboratory

    E-Print Network [OSTI]

    Mills, Richard

    and reactive transport in porous media. Apply it to field-scale studies of Geologic CO2 sequestrationModeling Reactive Flows in Porous Media Peter Lichtner (lead PI), Los Alamos National Laboratory NCCS Users Meeting March 28, 2007 #12;Introduction Companion to SciDAC-II project, "Modeling

  16. Passive Ozone Control Through Use of Reactive Indoor Wall and Ceiling Materials

    E-Print Network [OSTI]

    Siegel, Jeffrey

    Passive Ozone Control Through Use of Reactive Indoor Wall and Ceiling Materials Paper # 715 Donna A and unpainted drywall as passive ozone control surfaces in a room-sized laboratory chamber. Mean deposition-50%, resulted in increased reactivity for activated carbon. In our model for a typical house, about 35

  17. Relating maximum airway dilation and subsequent reconstriction to reactivity in human lungs

    E-Print Network [OSTI]

    Lutchen, Kenneth

    Relating maximum airway dilation and subsequent reconstriction to reactivity in human lungs Lauren in human lungs. J Appl Physiol 96: 1808­1814, 2004. First published February 6, 2004; 10.1152/japplphysiol reactivity in healthy lungs by prohibiting DI for an extended period. The present study had two goals. First

  18. A coupled THMC model of a heating and hydration laboratory experiment in unsaturated compacted FEBEX bentonite

    SciTech Connect (OSTI)

    Zheng, L.; Samper, J.; Montenegro, L.; Fernandez, A.M.

    2010-05-01T23:59:59.000Z

    Unsaturated compacted bentonite is foreseen by several countries as a backfill and sealing material in high-level radioactive waste repositories. The strong interplays between thermal (T), hydrodynamic (H), mechanical (M) and chemical (C) processes during the hydration stage of a repository call for fully coupled THMC models. Validation of such THMC models is prevented by the lack of comprehensive THMC experiments and the difficulties of experimental methods to measure accurately the chemical composition of bentonite porewater. We present here a non-isothermal multiphase flow and multicomponent reactive solute transport model for a deformable medium of a heating and hydration experiment performed on a sample of compacted FEBEX bentonite. Besides standard solute transport and geochemical processes, the model accounts for solute cross diffusion and thermal and chemical osmosis. Bentonite swelling is solved with a state-surface approach. The THM model is calibrated with transient temperature, water content and porosity data measured at the end of the experiment. The reactive transport model is calibrated with porewater chemical data derived from aqueous extract data. Model results confirm that thermal osmosis is relevant for the hydration of FEBEX bentonite while chemical osmosis can be safely neglected. Dilution and evaporation are the main processes controlling the concentration of conservative species. Dissolved cations are mostly affected by calcite dissolution-precipitation and cation exchange reactions. Dissolved sulphate is controlled by gypsum/anhydrite dissolution-precipitation. pH is mostly buffered by protonation/deprotonation via surface complexation. Computed concentrations agree well with inferred aqueous extract data at all sections except near the hydration boundary where cation data are affected by a sampling artifact. The fit of Cl{sup -} data is excellent except for the data near the heater. The largest deviations of the model from inferred aqueous extract data occur for dissolved SO{sub 4}{sup 2-} which is underpredicted by the model. There are uncertainties on the amount of gypsum available for dissolution and its dissolution mechanism (kinetics or local equilibrium).

  19. Final Report- Rejuvenating Permeable Reactive Barriers by Chemical Flushing, U.S. Environmental Protection Agency Region 8 Support

    Broader source: Energy.gov [DOE]

    Final Report - Rejuvenating Permeable Reactive Barriers by Chemical Flushing, U.S. Environmental Protection Agency Region 8 Support

  20. Local Dynamic Reactive Power for Correction of System Voltage Problems

    SciTech Connect (OSTI)

    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

    2008-12-01T23:59:59.000Z

    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.