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1

Coupled modeling of non-isothermal multiphase flow, solute transport and reactive chemistry in porous and fractured media: 1. Model Development and Validation  

E-Print Network (OSTI)

multiphase reactive transport, in Reactive transport in porousporous and fractured media under non-isothermal multiphaseporous and fractured media under non-isothermal multiphase

Xu, Tianfu; Pruess, Karsten

1998-01-01T23:59:59.000Z

2

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

Science Conference Proceedings (OSTI)

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 ... Keywords: CO2 geological storage, Environmental remediation, Multi-phase flow, Nuclear waste geological disposal, Reactive transport, TOUGHREACT

Tianfu Xu; Nicolas Spycher; Eric Sonnenthal; Guoxiang Zhang; Liange Zheng; Karsten Pruess

2011-06-01T23:59:59.000Z

3

TOUGHREACT-A simulation program for non-isothermal multiphase reactive geochemical transport in variably saturated geologic media: Applications to geothermal injectivity and CO2 geological sequestration  

Science Conference Proceedings (OSTI)

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 ... Keywords: CO2 geologic sequestration, Clay swelling, Geochemical transport, Hydrothermal systems, Injectivity enhancement, Mineral scaling, Mineral trapping, Reactive fluid flow, Saline aquifer, TOUGHREACT

Tianfu Xu; Eric Sonnenthal; Nicolas Spycher; Karsten Pruess

2006-03-01T23:59:59.000Z

4

A comparison of results obtained with two subsurface non-isothermal multiphase reactive transport simulators, FADES-CORE and TOUGHREACT  

E-Print Network (OSTI)

saturated porous media with multiphase flow. FADES-CORE hasisothermal multiphase flow with reactive transport in porousmultiphase flow with multicomponent reactive transport in porous

Juncosa Rivera, Ricardo; Xu, Tianfu; Pruess, Karsten

2001-01-01T23:59:59.000Z

5

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

DOE Green Energy (OSTI)

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.

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

2004-12-07T23:59:59.000Z

6

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

DOE Green Energy (OSTI)

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.

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

2010-08-01T23:59:59.000Z

7

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

DOE Green Energy (OSTI)

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.

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

2004-05-24T23:59:59.000Z

8

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

E-Print Network (OSTI)

flows of multiphase fluids in porous and fractured media,flows of multiphase fluids in porous and fractured media (Xu

Xu, T.

2010-01-01T23:59:59.000Z

9

TOURGHREACT: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media  

E-Print Network (OSTI)

flows of multiphase fluids in porous and fractured media.multiphase fluid and heat flow. The program is applicable to porous

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

2004-01-01T23:59:59.000Z

10

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

E-Print Network (OSTI)

1985) for fluid and heat flow in fractured porous media. Theflows of multiphase fluids in porous and fractured media,flows of multiphase fluids in porous and fractured media (Xu

Xu, T.

2010-01-01T23:59:59.000Z

11

TOURGHREACT: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media  

E-Print Network (OSTI)

for modeling fluid and heat flow in fractured porous media.flows of multiphase fluids in porous and fractured media.

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

2004-01-01T23:59:59.000Z

12

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

Science Conference Proceedings (OSTI)

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.

Xu, Tianfu; Pruess, Karsten

1998-09-01T23:59:59.000Z

13

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

Science Conference Proceedings (OSTI)

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

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

2008-09-29T23:59:59.000Z

14

TOUGHREACT: a new code of the TOUGH Family for Non-Isothermal multiphase reactive geochemical transport in variably saturated geologic media  

E-Print Network (OSTI)

multiphase flow, solute transport and reactive chemistry in porousmultiphase fluid flow, mass transport and chemical reactions, (2) we consider not only porous

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

2003-01-01T23:59:59.000Z

15

Subsurface Transport Over Reactive Multiphases (STORM): A general, coupled, nonisothermal multiphase flow, reactive transport, and porous medium alteration simulator, Version 2 user's guide  

Science Conference Proceedings (OSTI)

The Hanford Site, in southeastern Washington State, has been used extensively to produce nuclear materials for the US strategic defense arsenal by the Department of Energy (DOE) and its predecessors, the US Atomic Energy Commission and the US Energy Research and Development Administration. A large inventory of radioactive and mixed waste has accumulated in 177 buried single- and double shell tanks. Liquid waste recovered from the tanks will be pretreated to separate the low-activity fraction from the high-level and transuranic wastes. Vitrification is the leading option for immobilization of these wastes, expected to produce approximately 550,000 metric tons of Low Activity Waste (LAW) glass. This total tonnage, based on nominal Na{sub 2}O oxide loading of 20% by weight, is destined for disposal in a near-surface facility. Before disposal of the immobilized waste can proceed, the DOE must approve a performance assessment, a document that described the impacts, if any, of the disposal facility on public health and environmental resources. Studies have shown that release rates of radionuclides from the glass waste form by reaction with water determine the impacts of the disposal action more than any other independent parameter. This report describes the latest accomplishments in the development of a computational tool, Subsurface Transport Over Reactive Multiphases (STORM), Version 2, a general, coupled non-isothermal multiphase flow and reactive transport simulator. The underlying mathematics in STORM describe the rate of change of the solute concentrations of pore water in a variably saturated, non-isothermal porous medium, and the alteration of waste forms, packaging materials, backfill, and host rocks.

DH Bacon; MD White; BP McGrail

2000-03-07T23:59:59.000Z

16

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

E-Print Network (OSTI)

for modeling fluid and heat flow in fractured porous media:1985) for fluid and heat flow in fractured porous media. The

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

2004-01-01T23:59:59.000Z

17

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

SciTech Connect

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.

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

2011-02-14T23:59:59.000Z

18

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)

mineralogic model of Yucca Mountain, Nevada, Rev 2.0 . , Losfrom tuffs at Yucca Mountain, Nevada, USA. Geochim.in zeolitized tuffs at Yucca Mountain, Nevada, USA. Geochim.

Xu, Tianfu

2008-01-01T23:59:59.000Z

19

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)

for modeling fluid and heat flow in fractured porous media:1985) for fluid and heat flow in fractured porous media. The

Xu, Tianfu

2008-01-01T23:59:59.000Z

20

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)

Drift, heat was applied solely to the drift-center gridsquares) indicate grid block coordinates. Heat was appliedgrid block KCYC=KCYC+1 Time step: ?t Solve fluid and heat

Xu, Tianfu

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Non-isothermal CO2 flow through an injection well  

E-Print Network (OSTI)

Non-isothermal CO2 flow through an injection well Orlando SilvaOrlando Silva #12; The Problem CO2 or gas injection well Questions Injection of scCO2 vs. gaseous CO2. Other relevant examples: - gas and therefore the CO2 injection rate. caprock reservoir geothermal gradient hydrostatic gradient well CO2 bubble

Politècnica de Catalunya, Universitat

22

Microstructure evolution in TiN films reactively sputter deposited on multiphase substrates  

SciTech Connect

Cross-sectional transmission electron microscopy (X-TEM) has been used to investigate the microstructure of TiN films deposited by reactive magnetron sputtering onto ASP 30 high speed steel (HSS) substrates. ASP 30 is a multiphase material consisting of a martensitic matrix with MC and M/sub 6/C transition--metal particles embedded in it. The TiN films were approx.4 ..mu..m thick and were grown at substrate temperatures T/sub s/ between 200 and 550/sup 0/C. The X-TEM results showed that the film microstructure was very nonhomogeneous. A dense columnar morphology was observed above both the martensitic and M/sub 6/C substrate phases. The average column diameter ranged from 15 nm (T/sub s/ = 200/sup 0/C) to 50 nm (T/sub s/ = 550/sup 0/C) near the film/substrate interface over the martensitic phase and was in a factor of 2 less in the film regions adjacent to the M/sub 6/C phase. increased in both regions to 100 nm (T/sub s/ = 200/sup 0/C) to 150 nm (T/sub s/ = 550/sup 0/C) near the surface of the films. TiN grew epitaxially on MC particles but contained a high dislocation density which (except at 550/sup 0/C where some of the epitaxial grains extended throughout the entire film thickness) eventually coalesced to form low-angle grain boundaries and, finally, high-angle boundaries.

Helmersson, U.; Sundgren, J.; Greene, J.E.

1986-05-01T23:59:59.000Z

23

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

DOE Green Energy (OSTI)

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.

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

2008-10-15T23:59:59.000Z

24

Non-isothermal, compressible gas flow for the simulation of an enhanced gas recovery application  

Science Conference Proceedings (OSTI)

In this work, we present a framework for numerical modeling of CO"2 injection into porous media for enhanced gas recovery (EGR) from depleted reservoirs. Physically, we have to deal with non-isothermal, compressible gas flows resulting in a system of ... Keywords: Carbon dioxide sequestration, Enhanced gas recovery, Equation of state, Finite element method, Numerical simulation, Real gas behavior

N. BöTtcher; A. -K. Singh; O. Kolditz; R. Liedl

2012-12-01T23:59:59.000Z

25

Modeling and Simulation of Pore Scale Multiphase Fluid Flow and Reactive Transport in Fractured and Porous Media  

Science Conference Proceedings (OSTI)

In the subsurface fluids play a critical role by transporting dissolved minerals, colloids and contaminants (sometimes over long distances), by mediating dissolution and precipitation processes and enabling chemical transformations in solution and at mineral surfaces. Although the complex geometries of fracture apertures, fracture networks and pore spaces may make it difficult to accurately predict fluid flow in saturated (single-phase) subsurface systems, well developed methods are available. The simulation of multiphase fluid flow in the subsurface is much more challenging because of the large density and/or viscosity ratios found in important applications (water/air in the vadose zone, water/oil, water/gas, gas/oil and water/oil/gas in oil reservoirs, water/air/non-aqueous phase liquids (NAPL) in contaminated vadose zone systems and gas/molten rock in volcanic systems, for example). In addition, the complex behavior of fluid-fluid-solid contact lines, and its impact on dynamic contact angles, must also be taken into account, and coupled with the fluid flow. Pore network models and simple statistical physics based models such as the invasion percolation and diffusion-limited aggregation models have been used quite extensively. However, these models for multiphase fluid flow are based on simplified models for pore space geometries and simplified physics. Other methods such a lattice Boltzmann and lattice gas models, molecular dynamics, Monte Carlo methods, and particle methods such as dissipative particle dynamics and smoothed particle hydrodynamics are based more firmly on first principles, and they do not require simplified pore and/or fracture geometries. However, they are less (in some cases very much less) computationally efficient that pore network and statistical physics models. Recently a combination of continuum computation fluid dynamics, fluid-fluid interface tracking or capturing and simple models for the dependence of contact angles on fluid velocity at the contact line has been used to simulate multiphase fluid flow in fracture apertures, fracture networks and pore spaces. Fundamental conservation principles - conservation of momentum, and conservation of mass (or conservation of volume for incompressible fluids) and conservation of energy, as well as symmetries (Galilean invariance and isotropy) are central to the physics of fluids and the models used to simulate them. In molecular and mesoscale models observance of these conservation principles and symmetries at the microscopic level leads to macroscopic fluid dynamics that can be represented by the Navier Stokes equation. The remarkable fact that the flow of all simpe fluids, irrespective of their chemical nature, can be described by the Navier-Stokes equation is a result of these conservation principles and symmetries acting on the molecular level.

Paul Meakin; Alexandre Tartakovsky

2009-07-01T23:59:59.000Z

26

Structural characterization and dehydration kinetics of Kirka inderite mineral: Application of non-isothermal models  

SciTech Connect

Coats-Redfern, Arrhenius, Ozawa, Kissinger, and Doyle non-isothermal kinetic models were used to calculate the dynamic kinetic parameters for dehydration reaction of Mg-borate mineral, inderite (Kirka - Turkey) based on thermogravimetric analysis, derivative thermogravimetric analysis and differential thermal analysis. Dehydration experiments were carried out at different heating rates of 2, 5, 10, 15, and 20 deg. C/min in a pure nitrogen atmosphere. Structural and morphological properties have been characterized by X-Ray diffraction, Fourier transform-infrared spectroscopy, Scanning electron microscopy-energy dispersive spectroscopy, and Inductively coupled plasma-optical emission spectroscopy techniques.

Figen, Aysel Kantuerk, E-mail: akanturk@yildiz.edu.tr [Yildiz Technical University, Department of Chemical Engineering, Davutpasa Campus., N.127, Esenler, Istanbul (Turkey); Yilmaz, Muege Sari, E-mail: mugesari@yildiz.edu.tr [Yildiz Technical University, Department of Chemical Engineering, Davutpasa Campus., N.127, Esenler, Istanbul (Turkey); Piskin, Sabriye, E-mail: piskin@yildiz.edu.tr [Yildiz Technical University, Department of Chemical Engineering, Davutpasa Campus., N.127, Esenler, Istanbul (Turkey)

2010-06-15T23:59:59.000Z

27

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

E-Print Network (OSTI)

A model for multiphase ?ow and transport in porous mediaMultiphase ?ow ?elds in in-situ air sparging and its effect on remediation. Transp Porous

Wang, W.

2010-01-01T23:59:59.000Z

28

Multiphase Reactive Transport modeling of Stable Isotope Fractionation of Infiltrating Unsaturated Zone Pore Water and Vapor Using TOUGHREACT  

Science Conference Proceedings (OSTI)

Numerical simulations of transport and isotope fractionation provide a method to quantitatively interpret vadose zone pore water stable isotope depth profiles based on soil properties, climatic conditions, and infiltration. We incorporate the temperature-dependent equilibration of stable isotopic species between water and water vapor, and their differing diffusive transport properties into the thermodynamic database of the reactive transport code TOUGHREACT. These simulations are used to illustrate the evolution of stable isotope profiles in semiarid regions where recharge during wet seasons disturbs the drying profile traditionally associated with vadose zone pore waters. Alternating wet and dry seasons lead to annual fluctuations in moisture content, capillary pressure, and stable isotope compositions in the vadose zone. Periodic infiltration models capture the effects of seasonal increases in precipitation and predict stable isotope profiles that are distinct from those observed under drying (zero infiltration) conditions. After infiltration, evaporation causes a shift to higher 18O and D values, which are preserved in the deeper pore waters. The magnitude of the isotopic composition shift preserved in deep vadose zone pore waters varies inversely with the rate of infiltration.

Singleton, Michael J.; Sonnenthal, Eric L.; Conrad, Mark E.; DePaolo, Donald J.

2003-08-28T23:59:59.000Z

29

Multiphase Flow Modeling Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Science Chris Guenther, Director Computational Science Division RUA Spring Meeting, Morgantown, WV March 2013 2 NETL's Multiphase Flow Science Team * The Multiphase Flow Science...

30

Multiphase flow calculation software  

DOE Patents (OSTI)

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.

Fincke, James R. (Idaho Falls, ID)

2003-04-15T23:59:59.000Z

31

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

Science Conference Proceedings (OSTI)

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.

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

32

Multiphase Flow Modeling Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Science Science Chris Guenther, Director Computational Science Division RUA Spring Meeting, Morgantown, WV March 2013 2 NETL's Multiphase Flow Science Team * The Multiphase Flow Science Team develops physics-based simulation models to conduct applied scientific research. - Development of new theory - Extensive on-site and collaborative V&V efforts and testing - Engages in technology transfer - Applies the models to industrial scale problems. 3 Why is Multiphase Flow Science Needed? * Industry is increasingly relying on multiphase technologies to produce clean and affordable energy with carbon capture. * Unfortunately, the presence of a solid phase reduces the operating capacity of a typical energy device from its original design on average by 40% [1].

33

Multiphase fluid flow and subsequent geochemical transport in variably saturated fractured rocks: 1. Approaches  

E-Print Network (OSTI)

multiphase flow, solute transport and reactive chemistry in porousmultiphase flow, solute transport and reactive chemistry in porousmultiphase fluid flow, mass transport and chemical reactions, (2) we consider not only porous

Xu, Tianfu; Pruess, Karsten

2000-01-01T23:59:59.000Z

34

Free convection over a non-isothermal axisymmetric body immersed in a porous medium saturated with an electrically conducting non-Newtonian fluid  

E-Print Network (OSTI)

The study investigates the problem of magnetohydrodynamic (MHD) free convection over a non-isothermal axisymmetric body under the action of transverse magnetic field. The body is embedded in a porous medium saturated with electrically conducting non-Newtonian power law fluid. In order to obtain similarity solution, it is assumed that the viscosity of the fluid decays exponentially with temperature. The qualitative results are illustrated for a vertical flat plate, horizontal cylinder and sphere.

Shobha Bagai; Chandrashekhar Nishad

2013-09-30T23:59:59.000Z

35

Multiphase Stirling Engines  

E-Print Network (OSTI)

Analysis, design, fabrication, and experimental assessment of a symmetric three-phase free-piston Stirling engine system is discussed in this paper. The system is designed to operate with moderate-temperature heat input that is consistent with solar-thermal collectors. Diaphragm pistons and nylon flexures are considered for this prototype to eliminate surface friction and to provide appropriate seals. In addition, low loss diaphragm pistons, etched and woven-wire screen heat exchangers, and plastic flexures, as the main components of the system, are outlined. The experimental results are presented and compared with design analysis. Experiments successfully confirm the design models for heat exchanger flow friction losses and gas spring hysteresis dissipation. Furthermore, it is revealed that gas spring hysteresis loss is an important dissipation phenomenon for low-power Stirling engines and should be carefully addressed in design. Analysis shows that the gas hysteresis dissipation is reduced drastically by increasing the number of phases in a multiphase Stirling engine system. It is further shown that for an even number of phases, half of the engine chambers could be eliminated by utilizing a reversing mechanism within the multiphase system. The mathematical formulation and modal analysis of multiphase Stirling engine system are then extended to a system that incorporates a reverser. By introducing a reverser to the fabricated prototype, the system successfully operates in engine mode. The system proves its self-starting capability and validates the computed start-up temperature. ?DOI: 10.1115/1.3097274? 1

Artin Der Minassians; Seth R. Sanders

2009-01-01T23:59:59.000Z

36

'Multi-Phase' Steel Microstructures  

Science Conference Proceedings (OSTI)

Application of Conical Beam X-Ray Tomography to Multi-Phase Materials ... Digital Construction and Characterization of Reticulated Porous Microstructures ...

37

NETL: Methane Hydrates - DOE/NETL Projects  

NLE Websites -- All DOE Office Websites (Extended Search)

TOUGHREACT, a geochemical code for simulating chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media; and C.CANDI, a code used to describe...

38

Numerical analyses of effective dielectric constant of multiphase microporous media  

E-Print Network (OSTI)

dielectric constant of multiphase porous media are bettermicrostructures of multiphase porous media, and a latticemicrostructures of multiphase porous media and a lattice

Wang, Moran; Pan, Ning

2007-01-01T23:59:59.000Z

39

Optimization of the Refrigerant Capacity in Multiphase ...  

Science Conference Proceedings (OSTI)

Symposium, Magnetic Materials for Energy Applications. Presentation Title, Optimization of the Refrigerant Capacity in Multiphase Magnetocaloric Materials.

40

Using toughreact to model reactive fluid flow and geochemical transport in hydrothermal systems  

E-Print Network (OSTI)

multiphase flow, solute transport and reactive chemistry in porousmultiphase fluid flow, mass transport and chemical reactions, (2) reactive fluid flow and transport in fractured rocks as well as porous

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

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Flow assurance and multiphase pumping  

E-Print Network (OSTI)

A robust understanding and planning of production enhancement and flow assurance is required as petroleum E&P activities are targeting deepwaters and long distances. Different flow assurance issues and their solutions are put together in this work. The use of multiphase pumps as a flow assurance solution is emphasized. Multiphase pumping aids flow assurance in different ways. However, the problem causing most concern is sand erosion. This work involved a detection-based sand monitoring method. Our objectives are to investigate the reliability of an acoustic sand detector and analyze the feasibility of gel injection as a method to mitigate sand erosion. Use of a sand detector coupled with twin-screw pumps is studied under varying flow conditions. The feasibility of gel injection to reduce slip and transport produced solids through twin-screw pump is investigated. A unique full-scale laboratory with multiphase pumps was utilized to carry out the experimental tests. The test results indicate that acoustic sand detection works in a narrow window around the calibration signature. An empirical correlation for predicting the twin-screw pump performance with viscous fluids was developed. It shows good agreement in the practical operational limits – 50% to 100% speed. The results indicate that viscous gel injection should be an effective erosion mitigation approach as it reduces slip, the principle cause of erosive wear. To correlate the performance of viscous fluid injection to hydroabrasive wear, further experimental investigation is needed.

Nikhar, Hemant G.

2006-12-01T23:59:59.000Z

42

Numerical modeling of water injection into vapor-dominated geothermal reservoirs  

E-Print Network (OSTI)

non-isothermal multiphase conditions in porous media. FlowMultiphase Fracture-Matrix Interaction in Fractured Porous

Pruess, Karsten

2008-01-01T23:59:59.000Z

43

Modeling Macrosegregation with a Multiphase Approach  

Science Conference Proceedings (OSTI)

A multiphase approach is used to study the macrosegregation phenomena that ... caused by pore or gas bubble formation, deformation of the solid framework, ...

44

Multiphase Flow Analysis in Hydra-TH  

SciTech Connect

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.

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

45

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

E-Print Network (OSTI)

in modeling multiphase flow in porous and fractured media,multiphase tracer transport in heterogeneous fractured porousof multiphase flow through fractured or porous media.

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

2004-01-01T23:59:59.000Z

46

Efficient Schemes for Reducing Numerical Dispersion in Modeling Multiphase Transport through Porous and Fractured Media  

E-Print Network (OSTI)

within a fluid in a multiphase- porous-medium system isand radiation in a multiphase, multicomponent, porous mediumModeling Multiphase Transport through Porous and Fractured

Wu, Yu-Shu; Forsyth, Peter A.

2006-01-01T23:59:59.000Z

47

The TOUGH codes - a family of simulation tools for multiphase flow and transport processes in permeable media  

E-Print Network (OSTI)

Multiphase Tracer Transport in Heterogeneous Fractured PorousMultiphase Flow and Multicomponent Transport in Porous and

Pruess, Karsten

2003-01-01T23:59:59.000Z

48

Nanostructured Multi-Phase Titanium Based Materials Consolidated ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Nanostructured multi-phase titanium based materials were produced by severe ... Electrolytic Infiltration of Laser Sintered Porous Preforms.

49

Numerical simulation of single-phase and multiphase non-Darcy flow in porous and fractured reservoirs  

E-Print Network (OSTI)

well tests, multiphase flow, porous and fracturedin modeling multiphase flow in porous and fractured media,”description of multiphase flow through porous media: S w + S

Wu, Yu-Shu

2000-01-01T23:59:59.000Z

50

Modeling multiphase flow in porous medium systems at multiple scales.  

E-Print Network (OSTI)

??Problems involving multiphase flow and transport in porous media arise in a number of scientific and engineering applications including oil reservoir engineering and groundwater remediation.… (more)

Li, Huina.

2006-01-01T23:59:59.000Z

51

Isothermal Multiphase Fluid Flow and Capillary Instabilities in ...  

Science Conference Proceedings (OSTI)

... on the buoyant migration of a gas phase invading a saturated porous anode. ... and numerical computing that solve the multiphase dynamics at pore scale.

52

Discontinuous Galerkin formulation for multi-component multiphase flow.  

E-Print Network (OSTI)

??The understanding of multiphase multi-component transport in capillary porous media plays an important role in scientific and engineering disciplines such as the petroleum and environmental… (more)

Ho, Christina

2010-01-01T23:59:59.000Z

53

Multiphase Flow in a Steelmaking Converter Using an ...  

Science Conference Proceedings (OSTI)

Abstract Scope, The influence of an unconventional lance on the multiphase fluid ... However, the performance of the unconventional lance strongly depends on ...

54

Approval for Use of the Minnesota Multiphasic Personality Inventory...  

NLE Websites -- All DOE Office Websites (Extended Search)

OF HEAL TH, SAFETY AND SECURITY Approval for Use of Minnesota Multiphasic Personality Inventory-2 Revised Format and Psychological Assessment Inventory Under title IO, Code of...

55

Lessons learned from reactive transport modeling of a low-activity waste glass disposal system  

Science Conference Proceedings (OSTI)

A set of reactive chemical transport calculations were conducted with the Subsurface Transport Over Reactive Multiphases (STORM) code to evaluate the long-term performance of a representative low-activity waste glass in a shallow subsurface disposal ... Keywords: chemical transport, low-level waste, numerical model, unsaturated flow, vadose zone

Diana H. Bacon; B. Peter McGrail

2003-04-01T23:59:59.000Z

56

Shock Scattering in Multiphase Flow Model  

Science Conference Proceedings (OSTI)

Multiphase flow models have been proposed for use in situations which have combined Rayleigh-Taylor (RTI) and Richtmyer-Meshkov (RMI) instabilities. Such an approach works poorly for the case of a heavy to light shock incidence on a developed interface. The physical original of this difficulty is traced to an inadequate model of the interfacial pressure term as it appears in the momentum and turbulence kinetic energy equations. Constraints on the form of a better model from a variety of sources are considered. In this context it is observed that a new constraint on closures arises. This occurs because of the discontinuity within the shock responsible for the RMI. The proposed model (Shock Scattering) is shown to give useful results.

Klem, D

2003-10-16T23:59:59.000Z

57

Shock Scattering in a Multiphase Flow Model  

Science Conference Proceedings (OSTI)

Multiphase flow models have been proposed for use in situations which have combined Rayleigh-Taylor (RTI) and Richtmyer-Meshkov (RMI) instabilities. Such an approach work poorly for the case of a heavy to light shock incidence on a developed interface. The physical original of this difficulty is traced to an inadequate model of the interfacial pressure term as it appears in the momentum and turbulence kinetic energy equations. Constraints on the form of a better model from a variety of sources are considered. In this context it is observed that a new constraint on closures arises. This occurs because of the discontinuity within the shock responsible for the RMI. The proposed model (Shock Scattering) is shown to give useful results.

Klem, D

2003-04-08T23:59:59.000Z

58

Gasificaton Transport: A Multiphase CFD Approach & Measurements  

DOE Green Energy (OSTI)

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.

Dimitri Gidaspow; Veeraya Jiradilok; Mayank Kashyap; Benjapon Chalermsinsuwan

2009-02-14T23:59:59.000Z

59

Multiphase flow analysis of oil shale retorting  

DOE Green Energy (OSTI)

Several multiphase phenomena occur during oil shale retorting. An analysis is presented of two of these processes including condensation of oil shale vapor and oscillations of pressure in oil shale blocks through cracked bedding planes. Energy conservation equations for oil shale retorting, which include the effects associated with condensation of oil, are derived on the basis of two phase flow theory. It is suggested that an effective heat capacity associated with the latent heat of condensation should be included in the modeling of simulated modified in-situ oil shale retorting. A pressure propagation equation for fast transients in oil shale cracks has been derived and examined in view of existing experimental data. For slow processes, a limiting solution for maximum pressure in oil shale rocks has been obtained. Generation of high pressures in rocks by thermal or other means may lead to rock fracture which may be taken advantage of in modified in-situ oil shale processing.

Gidaspow, D.; Lyczkowski, R.W.

1978-09-18T23:59:59.000Z

60

Continuous multi-phase feeding of broiler chickens  

E-Print Network (OSTI)

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 of continuous multi-phase feeding during a 3-week starting period using battery brooders while experiments 3 and 4 evaluated multi-phase feeding during a traditional 7-week growing period using both battery brooders and floor pens. In the first and second experiments, the nutrient content of the multi-phase diets was changed every 24 hours in comparison to single-phase feeding. Results indicated that during the starter period, continuous multi-phase feeding had no significant influence on feed consumption, daily gain, feed to gain ratio or fecal nitrogen. In the third and fourth experiments, a four phase industry type broiler feeding program was compared to intensive multi-phase feeding programs created by linearly blending three different diets based on typical industry nutrient values and a commercial nutrient modeling computer program (EFG Natal®). In both intensive multi-phase feeding programs, the diets were changed every three days over a 7-week growth period. Broilers in experiment 3 were raised in Petersime battery brooders to primarily access nitrogen balance while birds in experiment 4 were raised in a floor pen on pine shaving litter to resemble commercial broiler production. The results indicated that intensive multi-phase feeding improved body weight gain and feed to gain ratio only in weeks 5 and 6 but not during the overall 7-week period. Nitrogen excretion and nitrogen retention were unaffected by the intensive multi-phase feeding systems. Economic analysis indicated that intensive multi-phase feeding programs could potentially lower feed costs per kilogram of gain. However, the high cost of implementing a continuous multi-phase feeding system may not justify the relatively small gain in lower feed cost per kilogram of gain. In conclusion, 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.

Nasril

2003-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

A model for multiphase flows through poroelastic media  

Science Conference Proceedings (OSTI)

A continuum model for multiphase fluid mixture flows through poroelastic media is presented. The basic conservation laws developed via a volume averaging technique are considered. Effects of phasic equilibrated forces are included in the model. Based on the thermodynamics of the multiphase mixture flows, appropriate constitutive equations are formulated. The entropy inequality is exploited, and the method of Lagrangian multiplier is used along with the phasic conservation laws to derive the constitutive equations for the phasic stress tensors, equilibrated stress vectors, and the interactions terms. The special cases of wave propagation in poroelastic media saturated with multiphase fluids, and multiphase flows through porous media, are studied. It is shown that the present theory leads to the extended Darcy’s law and contains, as a special case, Biot’s theory of saturated poroelastic media.

Ahmadi, Goodarz; Mazaheri, Ali Reza; Smith, D.H

2003-01-01T23:59:59.000Z

62

Multiphase Flow Dynamics 4: Nuclear Thermal Hydraulics, 1st edition  

Science Conference Proceedings (OSTI)

Volume 4 of the successful book package "Multiphase Flow" is devoted to nuclear thermal hydraulics which is a substantial part of nuclear reactor safety. It provides knowledge and mathematical tools for adequate description of the process of transferring ...

Nikolay I. Kolev

2009-06-01T23:59:59.000Z

63

NETL Publications: 2013 NETL Workshop on Multiphase Flow Science  

NLE Websites -- All DOE Office Websites (Extended Search)

2013 NETL Workshop on Multiphase Flow Science 2013 NETL Workshop on Multiphase Flow Science Tuesday, August 6, 2013 - Governors Ballroom, Lakeview Resort Registration (Grand Ballroom Foyer) Welcome and Introduction (Governors Ballroom) William Rogers, Leader - Multiphase Flow Team U.S. Department of Energy, National Energy Technology Laboratory NETL Multiphase Flow Research Overview Madhava Syamlal, Focus Area Leader - Computational and Basic Science Focus Area U.S. Department of Energy, National Energy Technology Laboratory Session Chair - Rahul Garg Application of a Filtered Euler-Lagrange Formalism to Large-Scale Simulations of Dilute and Dense Fluid-Particle Flows Jesse Capecelatro and Olivier Desjardins, Cornell University Heat Transfer in Fluidized Bed-Tube Heat Exchanger Amit Amritkar and DaneshTafti, Virginia Tech

64

MSTS - Multiphase Subsurface Transport Simulator theory manual  

SciTech Connect

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.

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

1993-05-01T23:59:59.000Z

65

NETL: 2009 Conference Proceedings - NETL 2009 Workshop on Multiphase Flow  

NLE Websites -- All DOE Office Websites (Extended Search)

NETL 2009 Workshop on Multiphase Flow Science NETL 2009 Workshop on Multiphase Flow Science Euro-Suites Hotel, Morgantown, WV April 22-23, 2009 Table of Contents Disclaimer Presentations Technology Roadmap, Workshop on Multiphase Flow Research, June 6-7, 2006 [PDF-45KB] Final Attendee List [PDF-21KB] PRESENTATIONS Kinetic Theory of Polydisperse Granular Flows and Validation Data [PDF-526KB] Christine Hrenya, Colorado University Quadrature-Based Moment Methods for Polydisperse Gas-Solid Flows [PDF-3.7MB] Rodney Fox, Iowa State University Fluid-Particle Drag Force in Bidisperse Suspensions [PDF-4.2MB] Sankaran Sundaresan, Princeton University Modeling Particle-Fluid Momentum Transfer in Polydisperse Gas-Solid Flows through Direct Numerical Simulations Based on the Immersed Boundary Method [PDF-2MB] Shankar Subramaniam, Iowa State University

66

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

SciTech Connect

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.

Joyce, E.L.

1997-03-01T23:59:59.000Z

67

Multiphase Flow Modeling of Biofuel Production Processes  

Science Conference Proceedings (OSTI)

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.

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

2011-06-01T23:59:59.000Z

68

NETL: News Release - NETL's Multiphase Flow Research Group Wins INCITE  

NLE Websites -- All DOE Office Websites (Extended Search)

December 19, 2008 December 19, 2008 NETL's Multiphase Flow Research Group Wins INCITE Award Award Brings 13,000,000 Processor Hours for Design of Clean and Efficient Coal Gasifiers Morgantown, W.Va. - The Multiphase Flow Research Group at the National Energy Technology Laboratory (NETL) has won a 2009 Innovative and Novel Computational Impact on Theory and Experiment (INCITE) award from the U.S. Department of Energy for their proposal "Clean and Efficient Coal Gasifier Designs using Large-Scale Simulations." This is the second consecutive year that the team has won an INCITE award. The NETL project is one of 66 to receive INCITE awards for 2009. According to the Energy Department's Office of Science, the projects address "some of the greatest scientific challenges" and will receive access to "some of the world's most powerful supercomputers."

69

Impact of wettability correlations on multiphase flow through porous media  

E-Print Network (OSTI)

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.

Marta S. de La Lama; Martin Brinkmann

2012-05-31T23:59:59.000Z

70

System for measuring multiphase flow using multiple pressure differentials  

DOE Patents (OSTI)

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.

Fincke, James R. (Idaho Falls, ID)

2003-01-01T23:59:59.000Z

71

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

DOE Green Energy (OSTI)

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. Efforts have focused on the Farnham Dome field, located in central Utah, the Springerville-St. Johns field in Arizona and New Mexico, and most recently, the Crystal Geyser-Salt Wash graben areas with their CO{sub 2}-charged geysers and springs in central Utah. At both the Springerville-St. Johns field and the central Utah CO{sub 2} spring area, there is evidence of extensive travertine deposits that document release of CO{sub 2} to the atmosphere. At Farnham Dome, calcite debris fields appear to be remnants of vein calcite and an earlier period of fluid leakage. The main achievements during this quarter are (1): preparation for a soil gas flux survey in October at the Crystal Geyser --Little Grand Wash fault zone, and the Salt Wash graben; (2) submission of an abstract to the upcoming Measurement, Monitoring and Verification session at the Fall AGU meeting; (3) submission of an invited abstract to the Gordon Conference on Hydrocarbon Resources; and (4) receipt of initial radiocarbon dates of travertine from the Springerville-St Johns field. Analytical results and interpretations of both the travertine deposition and the soil gas surveys are still in progress, and will be included in future quarterly reports.

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

2004-10-25T23:59:59.000Z

72

REACTIVE MULTIPHASE BEHAVIOR OF CO{sub 2} IN SALINE AQUIFERS BENEATH THE COLORADO PLATEAU  

DOE Green Energy (OSTI)

Soil gas surveys have been carried out on the Colorado Plateau over areas with natural occurrences of CO{sub 2}. At Farnham Dome, Utah, and Springerville-St. Johns, Arizona, proven CO{sub 2} reservoirs occur at 600-800 m depth, but no anomalous soil gas CO{sub 2} flux was detected. Background CO{sub 2} fluxes of up to about 5 g m{sup -2} day{sup -1} were common in arid, poorly vegetated areas, and fluxes up to about 20 g m{sup -2} day{sup -1} were found at Springerville-St. Johns in heavily vegetated, wet ground adjacent to springs. These elevated fluxes are attributed to shallow root zone activity rather than to a deep upflow of CO{sub 2}. Localized areas of anomalously high CO{sub 2} gas flux ({approx} 100 g m{sup -2} day{sup -1}) were documented along the Little Grand Wash Fault Zone near Crystal Geyser, Utah and nearby in Ten Mile Graben, but those in Ten Mile Graben are not directly associated with the major faults. In both areas, features with a visible gas flux are present. Isotopic measurements on the CO{sub 2} gas confirm that it originated at depth. Evidence of widespread vein calcite at the surface at Farnham Dome and travertine deposits in the other areas suggests that there has been an outflow of CO{sub 2}-rich fluids in the past. 14C ages of pollen trapped in the travertine at Springerville-St. Johns record a period of CO{sub 2} leakage to the atmosphere between 887 {+-} 35 and 3219 {+-} 30 years BP. No travertine deposits appear to be currently forming. At Springerville-St. Johns, Crystal Geyser and Ten Mile Graben, there are significant outflows of high-bicarbonate water. Movement of CO{sub 2}-rich groundwaters may be the dominant mechanism controlling the mobility of CO{sub 2} today. The very localized nature of the soil gas anomalies, evidence of large scale discharge of CO{sub 2} over a very short period of time and the outflow of ground water containing dissolved CO{sub 2} will present challenges for effective, long term monitoring of CO{sub 2} leakage.

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

2005-02-08T23:59:59.000Z

73

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

Science Conference Proceedings (OSTI)

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.

None

2005-07-01T23:59:59.000Z

74

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

Science Conference Proceedings (OSTI)

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).

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

2003-06-30T23:59:59.000Z

75

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

Science Conference Proceedings (OSTI)

Soil CO{sub 2} flux surveys have been conducted over known CO{sub 2} reservoirs at Farnham Dome, Utah, Crystal Geyser-Ten Mile Graben in Utah and Springerville-St. Johns, Arizona. No anomalous CO{sub 2} flux was detected at the Farnham Dome and Springerville-St. Johns. At Crystal Geyser-Ten Mile Graben, localized areas of anomalously high CO{sub 2} flux ({approx}100 g m{sup -2} day{sup -1}) occur along a fault zone near visibly degassing features. Isotopic measurements on CO{sub 2} collected from nearby springs indicate that it originated at depth. Evidence of widespread vein calcite at the surface (Farnham Dome) and travertine deposits at the other two areas suggests that discharge of CO{sub 2}-rich fluids has occurred in the past. Despite the lack of evidence for significant present day leakage of CO{sub 2} to the atmosphere at Springerville-St. Johns and Crystal Geyser-Ten Mile Graben, there are significant outflows of high-bicarbonate water in both areas suggesting continuous migration of CO{sub 2} in the aqueous phase from depth. The very localized nature of the CO{sub 2} flux anomalies, and the outflow of ground water containing dissolved CO{sub 2} present challenges for effective, long term monitoring of CO{sub 2} leakage.

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

2005-05-16T23:59:59.000Z

76

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

E-Print Network (OSTI)

and 80 0 C. Applied Geochemistry, 13, 905-916. Brown, P.W. ,and 80 0 C. Applied Geochemistry, 13, 905-916. de Combarieu,cells. Applied Geochemistry, 21, 977-992. Finsterle, S. ,

Xu, T.

2009-01-01T23:59:59.000Z

77

The Existence of a Multi-Phase Critical Point in Metastable Fcc ...  

Science Conference Proceedings (OSTI)

Presentation Title, The Existence of a Multi-Phase Critical Point in Metastable Fcc Ordering Phase Diagrams and Its Influence on Phase Diagram Features, ...

78

Towards Development of a Multiphase Simulation Model Using Lattice Boltzmann Method (LBM).  

E-Print Network (OSTI)

??Lattice Boltzmann Method is evolving as a substitute to the prevalent and predominant CFD modeling especially in cases such as multiphase flows, porous media flows… (more)

Koosukuntla, Narender Reddy

2011-01-01T23:59:59.000Z

79

Pore-scale modeling of the impact of surrounding flow behavior on multiphase flow properties.  

E-Print Network (OSTI)

??Accurate predictions of macroscopic multiphase flow properties, such as relative permeability and capillary pressure, are necessary for making key decisions in reservoir engineering. These properties… (more)

Petersen, Robert Thomas

2010-01-01T23:59:59.000Z

80

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

E-Print Network (OSTI)

??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… (more)

Bajaj, Reena

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

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

E-Print Network (OSTI)

modeling fluid and heat flow in fractured porous media, Soc.fluid and heat flows of multiphase, multicomponent fluid mixtures in porous and fractured media.

Mukhopadhyay, S.

2009-01-01T23:59:59.000Z

82

Efficient Schemes for Reducing Numerical Dispersion in Modeling Multiphase Transport through Porous and Fractured Media  

E-Print Network (OSTI)

involved. These heat-transfer processes are complicated byprocesses of multiphase flow, chemical transport, and heat transfertransport, and heat transfer, we assume that these processes

Wu, Yu-Shu; Forsyth, Peter A.

2006-01-01T23:59:59.000Z

83

Characteristics and Non-Isothermal Crystallization Kinetics of ...  

Science Conference Proceedings (OSTI)

Nickel Recovery from Sukinda Chromite Overburden Using Shewanella Putrefaciens · Optimization of Process Parameters on the Siffusion Bonding of a ...

84

Multi-phase back contacts for CIS solar cells  

DOE Patents (OSTI)

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.

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

1995-12-19T23:59:59.000Z

85

Interfacial Pressures and Shocks in a Multiphase Flow mix Model  

Science Conference Proceedings (OSTI)

Multiphase flow models have been proposed for use in situations which have combined Rayleigh-Taylor (RTI) and Richtmyer-Meshkov (RMI) instabilities [2, 3]. Such an approach works poorly for the case of a heavy to light shock incidence on a developed interface. I suggest that this difficulty can be overcome by adding an additional source to the turbulence kinetic energy equation. A variety of constraints on such a source are considered. In this context it is observed that a new constraint on closures arises. This occurs because of the discontinuity within the shock responsible for the RMI. The proposed model (Shock Scattering) is shown to give useful results.

Klem, D E

2004-10-01T23:59:59.000Z

86

A finite element approach for multiphase fluid flow in porous media  

Science Conference Proceedings (OSTI)

The main scope of this work is to carry out a mathematical framework and its corresponding finite element (FE) discretization for the partially saturated soil consolidation modelling in presence of an immiscible pollutant. A multiphase system with the ... Keywords: Consolidation, Finite elements, Immiscible pollutants, Mixture theory, Multiphase porous media

Javier L. Mroginski; H.Ariel Di Rado; Pablo A. Beneyto; Armando M. Awruch

2010-09-01T23:59:59.000Z

87

An energy preserving formulation for the simulation of multiphase turbulent flows  

Science Conference Proceedings (OSTI)

In this manuscript we propose an energy preserving formulation for the simulation of multiphase flows. The new formulation reduces the numerical diffusion with respect to previous formulations dealing with multiple phases, which makes this method to ... Keywords: Advection scheme, Multiphase flows, Turbulence

D. Fuster

2013-02-01T23:59:59.000Z

88

A Lagrangian, stochastic modeling framework for multi-phase flow in porous media  

Science Conference Proceedings (OSTI)

Many of the complex physical processes relevant for compositional multi-phase flow in porous media are well understood at the pore-scale level. In order to study CO"2 storage in sub-surface formations, however, it is not feasible to perform simulations ... Keywords: Lagrangian approach, Multi-phase flow, PDF method, Porous media, Stochastic particle method

Manav Tyagi; Patrick Jenny; Ivan Lunati; Hamdi A. Tchelepi

2008-06-01T23:59:59.000Z

89

Multiscale finite-volume method for compressible multiphase flow in porous media  

Science Conference Proceedings (OSTI)

The Multiscale Finite-Volume (MSFV) method has been recently developed and tested for multiphase-flow problems with simplified physics (i.e. incompressible flow without gravity and capillary effects) and proved robust, accurate and efficient. However, ... Keywords: compressibility, finite-volume methods, multiphase flow in porous media, multiscale methods, reservoir simulation

Ivan Lunati; Patrick Jenny

2006-08-01T23:59:59.000Z

90

A variational multiscale finite element method for multiphase flow in porous media  

Science Conference Proceedings (OSTI)

We present a stabilized finite element method for the numerical solution of multiphase flow in porous media, based on a multiscale decomposition of pressures and fluid saturations into resolved (or grid) scales and unresolved (or subgrid) scales. The ... Keywords: Conservation laws, Finite elements, Multiphase flow, Porous media, Shocks, Stabilized methods, Variational multiscale, Waterflood

Ruben Juanes

2005-04-01T23:59:59.000Z

91

A variational multiscale finite element method for multiphase flow in porous media  

Science Conference Proceedings (OSTI)

We present a stabilized finite element method for the numerical solution of multiphase flow in porous media, based on a multiscale decomposition of pressures and fluid saturations into resolved (or grid) scales and unresolved (or subgrid) scales. The ... Keywords: conservation laws, finite elements, multiphase flow, porous media, shocks, stabilized methods, variational multiscale, waterflood

Ruben Juanes

2005-04-01T23:59:59.000Z

92

A simulation model for the fabrication of components made from multiphase perfect materials  

Science Conference Proceedings (OSTI)

A component, which has an optimized combination of different materials (including homogeneous materials and different types of heterogeneous materials) in its different portions for a specific application, is considered as the component made of a multiphase ... Keywords: Layered manufacturing, Multiphase perfect materials, Simulation, Virtual component, Virtual manufacturing

Feng Wang; Ke-Zhang Chen; Xin-An Feng

2008-08-01T23:59:59.000Z

93

Fladmark. Parallel simulation of multiphase/multicomponent flow models  

E-Print Network (OSTI)

Summary. The simulation of flow in porous media is a computationally demanding task. Thermodynamical equilibrium calculations and complex, heterogeneous geological structures normally gives a multiphysics/multidomain problem to solve. Thus, efficient solution methods are needed. The research simulator Athena is a 3D, multiphase, multicomponent, porous media flow simulator. A parallel version of the simulator was developed based on a non-overlapping domain decomposition strategy, where the domains are defined a-priori from e.g. geological data. Selected domains are refined with locally matching grids, giving a globally non-matching, unstructured grid. In addition to the space domain, novel algorithms for parallel processing in time based on a predictor-corrector strategy has been successfully implemented. We discuss how the domain decomposition framework can be used to include different physical and numerical models in selected sub-domains. Also we comment on how the two-level solver relates to multiphase upscaling techniques. Adding communication functionality enables the original serial version to run on each sub-domain in parallel. Motivated by the need for larger time steps, an implicit formulation of the mass transport equations has been formulated and implemented in the existing parallel framework. Further, as the Message Passing Interface (MPI) is used for communication, the simulator is highly portable. Through benchmark experiments, we test the new formulation on platforms ranging from commercial super-computers to heterogeneous networks of workstations. 1

Erlend Øian; Magne S. Espedal; I. Garrido; G. E. Fladmark

2004-01-01T23:59:59.000Z

94

Interface effects on multiphase flows in porous media  

Science Conference Proceedings (OSTI)

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.

Zhang, Duan Z [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

95

Modeling of thermal transport properties of multiphase porous materials  

Science Conference Proceedings (OSTI)

This work presents a numerical framework for modeling thermal transport properties of multiphase porous materials with complex internal microstructures. The framework includes two steps. First, a random generation-growth algorithm is highlighted for reproducing multiphase microstructures, statistically equivalent to the actual systems, based on the geometrical and morphological information obtained from measurements and experimental estimations. Then a high-efficiency lattice Boltzmann solver for the corresponding governing equations is described, which, while assuring energy conservation and appropriate continuities at the interfaces in a complex system, has demonstrated its numerical power in yielding accurate solutions. Various applications are provided to validate the feasibility, effectiveness and robustness of this new framework by comparing the predictions with existing experimental data for different transport processes, accounting for the effects due to internal morphology, microstructural anisotropy, and multi phase interactions. The examples given also suggest potential applicability of this methodology to other problems as long as they are governed by similar partial differential equation(s). Thus, for given composition and structure, this numerical methodology is in essence a model built on sound physics principles with prior validity, without resorting to any ad hoc empirical treatment. Therefore, it is useful for design and optimization of new materials, beyond just predicting and analyzing the existing ones.

Wang, Moran [Los Alamos National Laboratory; Kang, Qinjun [Los Alamos National Laboratory; Robinson, Bruce [Los Alamos National Laboratory; Ning, Pan [UC DAVIS

2010-01-01T23:59:59.000Z

96

Uncertainty Quantification Tools for Multiphase Flow Simulations using MFIX  

NLE Websites -- All DOE Office Websites (Extended Search)

Uncertainty Uncertainty Quantification Tools for Multiphase Flow Simulations using MFIX X. Hu 1 , A. Passalacqua 2 , R. O. Fox 1 1 Iowa State University, Department of Chemical and Biological Engineering, Ames, IA 2 Iowa State University, Department of Mechanical Engineering, Ames, IA Project Manager: Steve Seachman University Coal Research and Historically Black Colleges and Universities and Other Minority Institutions Contractors Review Conference Pittsburgh, June 11 th - 13 th 2013 X. Hu, A. Passalacqua, R. O. Fox (ISU) Uncertainty quantification DOE-UCR Review Meeting 2013 1 / 44 Outline 1 Introduction and background 2 Project objectives and milestones 3 Technical progress Univariate case Multivariate case Code structure 4 Future work X. Hu, A. Passalacqua, R. O. Fox (ISU) Uncertainty quantification DOE-UCR Review Meeting 2013 2 / 44 Introduction and background Outline 1 Introduction

97

Iterative methods for solving the pressure problem at multiphase filtration  

E-Print Network (OSTI)

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.

Vabishchevich, P

2011-01-01T23:59:59.000Z

98

A New Multiphase Model for Simulating Energetically Driven Particles  

SciTech Connect

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.

Stevens, D E; Murphy, M J

2010-02-02T23:59:59.000Z

99

A programmable CCD driver circuit for multiphase CCD operation  

Science Conference Proceedings (OSTI)

A programmable CCD driver circuit was designed to drive CCD's in multiphased modes. The purpose of the drive electronics was to operate developmental CCD imaging arrays for NASA's Moderate Resolution Imaging Spectrometer - Tiltable (MODIS-T). Five prototype arrays were designed. Valid's Graphics Editor (GED) was used to design the driver. With this driver design, any of the five arrays can be readout. Designing the driver with GED allowed functional simulation, timing verification, and certain packaging analyses to be done on the design before fabrication. The driver verified its function with the master clock running up to 10 MHz. This suggests a maximum rate of 400 Kpixels/sec. Timing and packaging parameters were verified. the design uses 54 TTL component chips.

Ewin, A.J.; Reed, K.V.

1989-02-01T23:59:59.000Z

100

Scaling Relations for Turbulence in Multiphase Interstellar Medium  

E-Print Network (OSTI)

We simulate the dynamics of phase transition in radiatively cooling interstellar gas in three dimensions with a high order hydrodynamic method. We have previously shown (Kritsuk & Norman 2002a) in simulations with non-equilibrium initial conditions that thermal instability induces supersonic turbulence as a by-product of the phase transition which leads to formation of multiphase medium. We rely on a generalization of the She & Leveque (1994) model to study velocity scaling relations in this decaying turbulence and compare those with analogous results for compressible isothermal turbulence. Since radiative cooling promotes nonlinear instabilities in highly supersonic flows, turbulence in our simulations tends to be more intermittent than in the isothermal case. Hausdorff dimension of the most singular dissipative structures, D, can be as high as 2.3, while in supersonic isothermal turbulence D is limited by a more primitive nature of dissipation (shocks): D<=2. We also show that single-phase veloci...

Kritsuk, A G; Kritsuk, Alexei G.; Norman, Michael L.

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Multi-Phase Galaxy Formation and Quasar Absorption Systems  

E-Print Network (OSTI)

Abstract. 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.

P. R. Williams; C. Shu; B. Ménard; Ariyeh H. Maller

2005-01-01T23:59:59.000Z

102

Multi-Phase Galaxy Formation and Quasar Absorption Systems  

E-Print Network (OSTI)

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.

Ariyeh H. Maller

2005-05-06T23:59:59.000Z

103

Multi-Phase Galaxy Formation and Quasar Absorption Systems  

E-Print Network (OSTI)

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.

Maller, A H

2005-01-01T23:59:59.000Z

104

Azo Dyes and Their Interfacial Activity: Implications for Multiphase Flow Experiments  

Science Conference Proceedings (OSTI)

Interfacial effects play an important role in governing multiphase fluid behavior in porous media (Neustadter 1984; Tuck et al. 1988). For instance, several dimensionless numbers have been developed to express important force ratios applicable to multiphase flow in porous media (Morrow and Songkran 1981; Chatzis and Morrow 1984; Wardlaw 1988; Pennell et al. 1996; Dawson and Roberts 1997). These force ratios emphasize the importance of interfacial properties. Our objectives are to provide chemical information regarding the dyes commonly used in multiphase flow visualization studies and to show the surface chemistry effects of the most commonly used dye, Sudan IV, in the tetrachloroethylene (PCE)-water-glass system

Tuck, D.M.

1999-04-21T23:59:59.000Z

105

Separator Design for Use in High GVF Multiphase Flow  

E-Print Network (OSTI)

The requirement of bringing an outside coolant source to run through the seals of a multiphase pump has always been a costly endeavor. Using a separator to extract liquid from the exhaust of the pump to use as a coolant is often more expensive than providing an outside source of coolant. This research proposes a cost effective separator design which efficiently separates the liquid from gas, while maintaining a high enough residence time to remove any gas entrainment, and separates only the seal flush requirement by letting any excess liquids carryover with the gas. Conventional multiphase separators operate by substantially decreasing the velocity of the mixture, which reduces the drag force put forth by the gasses and allows gravity to force the liquids downward. Gas-Liquid Cylindrical Cyclones (GLCCs) operate by increasing the velocity of the mixture, using radial force to separate liquids and gasses. This technique requires a smaller diameter vessel to achieve separation. The separator in this research uses gravity as the separation force while maintaining a pipe diameter similar to the GLCC. This way, only standard pipe and pipe fittings are used. The effectiveness of this design is measured two ways. First, efficiency is studied at varying gas volume fractions (GVFs), velocities, pressures, and pipe diameters. Second, the length of air entrainment (LAE) is measured at the same varying conditions. The efficiency and air entrainment studies provide design recommendations to accommodate seal flush requirements and size limitations. The following investigation also offers further areas of research to improve the understanding and modeling of using standard pipe and pipe fittings to create more effective design equations.

Cihak, Daniel

2012-08-01T23:59:59.000Z

106

Fluid Dynamic and Performance Behavior of Multiphase Progressive Cavity Pumps  

E-Print Network (OSTI)

It is common for an oil well to produce a mixture of hydrocarbons that flash when exposed to atmospheric pressure. The separation of oil and gas mixtures on site may prove expensive and lead to higher infrastructure and maintenance costs as well. A multiphase pump offers a good alternative with a lower capital cost and increased overall production. A Progressive Cavity Pump (PCP) is a positive displacement pump type that can be used to pump a wide range of multiphase mixtures, including high viscosity fluids with entrained gas and solid particles in suspension. Despite its advantages, a PCP has a reduced ability to handle high gas-liquid ratios due to limitations of its elastomeric stator material required to overcome thermo and mechanical effects. Also the efficiency decreases significantly with increases in gas volume fractions and reduced differential pressures. The current study focuses on studying the behavior of this unique pump in a wide range of GVFs and studying the effect of this ratio on overall efficiency, temperature and pressure distribution on the stator. The pump exhibits vibration issues at specific differential pressures and they have been studied in this work. This can be of critical value as severe vibration issues can damage the pump components such as couplings and bearings leading to high maintenance costs. Another important issue addressed by this research is the behavior of this pump in transient conditions. Oil well production is highly unpredictable with unexpected rises and drops in GVFs. These transient conditions have been simulated by varying the GVF over wide ranges and studying the pump's behavior in terms of load, temperature rises and instantaneous pressure profiles on the pump stator. This thesis provides a comprehensive study of this pump, its operating ranges and behavior in off-design conditions to assist oil and gas exploration ventures in making an informed choice in pump selection for their applications based on field conditions.

Narayanan, Shankar Bhaskaran

2011-08-01T23:59:59.000Z

107

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

E-Print Network (OSTI)

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 ...

Bajaj, Reena

2009-01-01T23:59:59.000Z

108

Influence of Solid-Liquid-Liquid Interactions on Multiphase Transport Behavior in Porous Media  

Science Conference Proceedings (OSTI)

The flow of oil, water and gas in the complex network of paths in petroleum reservoir rocks constitutes probably the most complex embodiment of interfacial interactions and their consequences on multiphase transport behavior in porous media. The fact ...

Dandina N. Rao; Subhash C. Ayirala

2005-07-01T23:59:59.000Z

109

Lipid Oxidation PathwaysChapter 9 Protein Alterations Due to Lipid Oxidation in Multiphase Systems  

Science Conference Proceedings (OSTI)

Lipid Oxidation Pathways Chapter 9 Protein Alterations Due to Lipid Oxidation in Multiphase Systems Health Nutrition Biochemistry eChapters Health - Nutrition - Biochemistry Press Downloadable pdf of Chapter 9 P

110

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

E-Print Network (OSTI)

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 ...

Suckale, Jenny

2011-01-01T23:59:59.000Z

111

Effects of buoyancy source composition on multiphase plume behavior in stratification  

E-Print Network (OSTI)

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 ...

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

2004-01-01T23:59:59.000Z

112

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

Science Conference Proceedings (OSTI)

We describe a simple mapped-grid approach for the efficient numerical simulation of compressible multiphase flow in general multi-dimensional geometries. The algorithm uses a curvilinear coordinate formulation of the equations that is derived for the ... Keywords: 35L60, 58J45, 65M06, 65M50, 65Y15, Compressible multiphase flow, Fluid-mixture model, Mapped grids, Stiffened gas equation of state, Wave-propagation method

K. -M. Shyue

2010-11-01T23:59:59.000Z

113

System for reactivating catalysts  

DOE Patents (OSTI)

A method of reactivating a catalyst, such as a solid catalyst or a liquid catalyst is provided. The method comprises providing a catalyst that is at least partially deactivated by fouling agents. The catalyst is contacted with a fluid reactivating agent that is at or above a critical point of the fluid reactivating agent and is of sufficient density to dissolve impurities. The fluid reactivating agent reacts with at least one fouling agent, releasing the at least one fouling agent from the catalyst. The at least one fouling agent becomes dissolved in the fluid reactivating agent and is subsequently separated or removed from the fluid reactivating agent so that the fluid reactivating agent may be reused. A system for reactivating a catalyst is also disclosed.

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

2010-03-02T23:59:59.000Z

114

Design and Development of Integrated Compact Multiphase Separation System (CMSS)  

SciTech Connect

The petroleum industry has relied in the past mainly on conventional vessel-type separators, which are bulky, heavy and expensive, to process wellhead production of oil-water-gas flow. Economic and operational pressures continue to force the petroleum industry to seek less expensive and more efficient separation alternatives in the form of compact separators. The compact dimensions, smaller footprint and lower weight of compact separators have a potential for cost savings to the industry, especially in offshore and subsea applications. Also, compact separators reduce the inventory of hydrocarbons significantly, which is critical for environmental This report presents a brief overview of the activities and tasks accomplished during the Budget Period II (October 09, 2004-April 30, 2006) of the DOE project titled ''Design and Development of Integrated Compact Multiphase Separation System (CMSS{copyright})''. An executive summary is presented initially followed by the tasks of the current budget period. Then, detailed description of the experimental and modeling investigations are presented. Subsequently, the technical and scientific results of the activities of this project period are presented with discussions. The findings of this investigation are summarized in the ''Conclusions'' section In this investigation, the concept of CMSS{copyright} has been developed and is proven through simulation studies and validated by experimental data. As part of the second phase of the project (Budget Period II--10/09/2004-04/30/2006) experimental investigation of the integrated CMSS{copyright} for different configurations has been conducted in order to evaluate the performance of the individual separation components, and determine how they will affect the performance of each other when integrated in the CMSS{copyright}. An intelligent control system is also developed to improve the total system efficiency of Compact Multiphase Separation System (CMSS{copyright}). In mature oil fields, water handling poses a huge problem. Thus water knock out at the earliest stage helps in significant cost savings during handling, separation and transportation of oil. One of the objectives of the CMSS{copyright} configuration is to knock out free water from the upstream fluids. The results from theoretical and experimental studies show that Free Water Knock Out (FWKO) CMSS{copyright} system can be readily deployed in the field using the control system strategies designed, implemented and tested in this study.

Ram S. Mohan; Ovadia Shoham

2006-04-30T23:59:59.000Z

115

Thermal Conduction and Multiphase Gas in Cluster Cores  

E-Print Network (OSTI)

We examine the role of thermal conduction and magnetic fields in cores of galaxy clusters through global simulations of the intracluster medium (ICM). In particular, we study the influence of thermal conduction, both isotropic and anisotropic, on the condensation of multiphase gas in cluster cores. Previous hydrodynamic simulations have shown that cold gas condenses out of the hot ICM in thermal balance only when the ratio of the cooling time ($t_{\\rm cool}$) and the free-fall time ($t_{\\rm ff}$) is less than $\\approx 10$. Since thermal conduction is significant in the ICM and it suppresses local cooling at small scales, it is imperative to include thermal conduction in such studies. We find that anisotropic (along local magnetic field lines) thermal conduction does not influence the condensation criterion for a general magnetic geometry, even if thermal conductivity is large. However, with isotropic thermal conduction cold gas condenses only if conduction is suppressed (by a factor $\\lesssim 0.3$) with respe...

Wagh, Baban; McCourt, Michael

2013-01-01T23:59:59.000Z

116

Development, Verification, and Validation of Multiphase Models for Polydisperse Flows  

Science Conference Proceedings (OSTI)

This report describes in detail the technical findings of the DOE Award entitled 'Development, Verification, and Validation of Multiphase Models for Polydisperse Flows.' The focus was on high-velocity, gas-solid flows with a range of particle sizes. A complete mathematical model was developed based on first principles and incorporated into MFIX. The solid-phase description took two forms: the Kinetic Theory of Granular Flows (KTGF) and Discrete Quadrature Method of Moments (DQMOM). The gas-solid drag law for polydisperse flows was developed over a range of flow conditions using Discrete Numerical Simulations (DNS). These models were verified via examination of a range of limiting cases and comparison with Discrete Element Method (DEM) data. Validation took the form of comparison with both DEM and experimental data. Experiments were conducted in three separate circulating fluidized beds (CFB's), with emphasis on the riser section. Measurements included bulk quantities like pressure drop and elutriation, as well as axial and radial measurements of bubble characteristics, cluster characteristics, solids flux, and differential pressure drops (axial only). Monodisperse systems were compared to their binary and continuous particle size distribution (PSD) counterparts. The continuous distributions examined included Gaussian, lognormal, and NETL-provided data for a coal gasifier.

Christine Hrenya; Ray Cocco; Rodney Fox; Shankar Subramaniam; Sankaran Sundaresan

2011-12-31T23:59:59.000Z

117

DETERMINATION OF MECHANICAL AND HYDRAULIC BEHAVIOR OF TENSILE FRACTURES UNDER MULTIPHASE FLOW USING X-RAY COMPUTED TOMOGRAPHY.  

E-Print Network (OSTI)

??Understanding fracture morphology in terms of a porous media is necessary for accurate simulation of multiphase transport in fractured rocks. Although ambient-stress methods for obtaining… (more)

Alvarado, Freddy

2005-01-01T23:59:59.000Z

118

Numerical simulation of single-phase and multiphase non-Darcy flow in porous and fractured reservoirs  

E-Print Network (OSTI)

modeling fluid and heat flow in fractured porous media, Soc.flow of single-phase and multi-phase fluids in porous and fractured media.

Wu, Yu-Shu

2000-01-01T23:59:59.000Z

119

Catalysis and Reactivity  

NLE Websites -- All DOE Office Websites (Extended Search)

understanding of basic principles of surface reactivity and its control by surface modification, on identification of active sites and full characterization of their electronic...

120

A validation process for multi-phase reacting flow CFD code  

DOE Green Energy (OSTI)

Computational fluid dynamic (CFD) code calculates flow properties for the analysis of a flow system. Flow properties are computed based on conservation principles and various phenomenological models. The accuracy of the computed flow properties highly depends on the validity of the models and the degree of numerical convergence. Validation of a CFD code is essential for application of an engineering system. Multiphase reacting flows are common in industrial applications and few CFD code are available. A CFD code was developed for the simulation of multiphase reacting flows. A validation process was also developed for such a CFD code. The validation was performed for several cases. Examples of industrial devices which are multiphase reacting flow systems include catalytic cracking reactors, glass melting furnaces, coal-fired combustors, and diesel engines.

Chang, S. L.; Zhou, C. Q.; Petrick, M.

2000-05-09T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Experimental analysis of pressure distribution in a twin screw compressor for multiphase duties  

SciTech Connect

This paper presents the results of an experimental investigation of pressure distribution inside working chamber of a twin screw compressor for multiphase duties. A mathematical model for describing the pressure distribution inside working chamber is proposed. By means of a small pressure transducer embedded into the groove at the root of the rotor, the pressure distributions of a multiphase compressor under various running conditions have been recorded successfully to verify the model. It is found that the pressure curve during the discharge process has a higher level under the conditions of the lower gas void fraction, higher discharge pressure, higher rotational speed and higher inlet pressure. The pressure distribution calculated by model in this paper shows good agreement with the data recorded by a small pressure sensor in a prototype multiphase compressor at the high gas void fractions under different operating conditions. (author)

Cao, Feng; Gao, Tieyu; Li, Songshan; Xing, Ziwen; Shu, Pengcheng [School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049 (China)

2011-01-15T23:59:59.000Z

122

A ghost fluid, level set methodology for simulating multiphase electrohydrodynamic flows with application to liquid fuel injection  

Science Conference Proceedings (OSTI)

In this paper, we present the development of a sharp numerical scheme for multiphase electrohydrodynamic (EHD) flows for a high electric Reynolds number regime. The electric potential Poisson equation contains EHD interface boundary conditions, which ... Keywords: Conservative level set, DNS, Electrohydrodynamics, Ghost fluid method, Multiphase flow, Primary atomization

B. P. Van Poppel; O. Desjardins; J. W. Daily

2010-10-01T23:59:59.000Z

123

TOUGH+CO2: A multiphase fluid-flow simulator for CO2 geologic sequestration in saline aquifers  

Science Conference Proceedings (OSTI)

TOUGH+CO"2 is a new simulator for modeling of CO"2 geologic sequestration in saline aquifers. It is a member of TOUGH+, the successor to the TOUGH2 family of codes for multicomponent, multiphase fluid and heat flow simulation. The code accounts for heat ... Keywords: CO2 geologic sequestration, Modeling, Multiphase flow, Parallel computing, Saline aquifer, TOUGH+, TOUGH2

Keni Zhang; George Moridis; Karsten Pruess

2011-06-01T23:59:59.000Z

124

Numerical simulation of air/water multiphase flows for ceramic sanitary ware design by multiple GPUs  

E-Print Network (OSTI)

8 Numerical simulation of air/water multiphase flows for ceramic sanitary ware design by multiple Compounds A Large-scale Simulation on CFD in Construction Industry Estimation of strong ground motion and manufacturing of plumbing products such as ceramic sanitary wares. In order to re-produce the complex

125

Dissipative Particle Dynamics Simulation of Pore-Scale Multiphase Fluid Flow  

Science Conference Proceedings (OSTI)

Multiphase fluid flow through porous media involves complex fluid dynamics, and it is difficult to model such complex behavior, on the pore scale, using grid-based continuum models. In this paper, the application of dissipative particle dynamics (DPD), a relatively new mesoscale method, to the simulation of pore-scale multiphase fluid flows under a variety of flow conditions is described. We demonstrate that the conventional DPD method using purely repulsive conservative (nondissipative) particle-particle interactions is capable of modeling single-phase flow fields in saturated porous media. In order to simulate unsaturated multiphase flow through porous media, we applied a modified model for the conservative particle-particle interactions that combines short-range repulsive and long-range attractive interactions. This form for the conservative particle-particle interactions allows the behavior of multiphase systems consisting of gases, liquids, and solids to be simulated. We also demonstrated that the flow of both wetting and nonwetting fluids through porous media can be simulated by controlling the ratios between the fluid-fluid and fluid-solid (fluid-wall) interparticle interaction strengths.

Paul Meakin; Hai Huang; Moubin Liu

2007-04-01T23:59:59.000Z

126

Adaptive multiscale finite-volume method for nonlinear multiphase transport in heterogeneous formations  

Science Conference Proceedings (OSTI)

In the previous multiscale finite-volume (MSFV) method, an efficient and accurate multiscale approach was proposed to solve the elliptic flow equation. The reconstructed fine-scale velocity field was then used to solve the nonlinear hyperbolic transport ... Keywords: Adaptivity, Multigrid, Multiphase flow, Multiscale finite-volume, Nonlinear transport, Porous media, Reservoir simulation

S. H. Lee; H. Zhou; H. A. Tchelepi

2009-12-01T23:59:59.000Z

127

Multiphase flow reconstruction in oil pipelines by capacitance tomography using simulated annealing  

E-Print Network (OSTI)

simulated annealing (SA) algorithm is applied to reconstruct permittivity images of real two-phase gas- oil such as mixing or stirring vessels, fluidized bed reactors, separator tanks and pipelines carrying multiphase in a cylindrical configuration close to the electrodes in order to improve resolution in the calculation

Martin, Roland

128

A Multiphase Traction/Fast-Battery-Charger Drive for Electric or Plug-in Hybrid Vehicles  

E-Print Network (OSTI)

A Multiphase Traction/Fast-Battery-Charger Drive for Electric or Plug-in Hybrid Vehicles Solutions and torque ripples. Keywords- Electric Vehicle, Plug-in Hybrid Vehicle, On-board Battery Charger, H on an original electric drive [1]-[3] dedicated to the vehicle traction and configurable as a battery charger

Paris-Sud XI, Université de

129

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

E-Print Network (OSTI)

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.

Shigeki Matsutani; Kota Nakano; Katsuhiko Shinjo

2011-07-13T23:59:59.000Z

130

Reactive Transport and Coupled THM Processes in Engineering Barrier Systems (EBS)  

E-Print Network (OSTI)

of geological porous media with multiphase flow: Theory andmultiphase flow, solute transport andreactive chemistry in porousMultiphase Fluid Flow, Heat Transfer, and Deformation in Fractured Porous

Steefel, Carl

2010-01-01T23:59:59.000Z

131

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

SciTech Connect

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.

Evans, R.D.; Civan, F.

1992-12-31T23:59:59.000Z

132

Characterization of non-Darcy multiphase flow in petroleum bearing formations. [Quarterly] report, January 1--March 30, 1993  

SciTech Connect

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 January 1993--March 1993 was focused upon theoretical and experimental studies to more accurately describe multiphase flow in porous media.

Evans, R.D.; Civan, F.

1993-12-31T23:59:59.000Z

133

Reactive Power Compensator.  

DOE Patents (OSTI)

A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation. 26 figs.

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

1992-07-28T23:59:59.000Z

134

Reactive power compensator  

DOE Patents (OSTI)

A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

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

1992-01-01T23:59:59.000Z

135

Microsoft Word - treact_manual.doc  

Office of Scientific and Technical Information (OSTI)

1 1 LBNL-55460 TOUGHREACT User's Guide: A Simulation Program for Non- isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media Tianfu Xu, Eric Sonnenthal, Nicolas Spycher , and Karsten Pruess Earth Sciences Division, Lawrence Berkeley National Laboratory University of California, Berkeley, CA 94720. May 2004 This work was supported by the Laboratory Directed Research and Development Program of the Ernest Orlando Lawrence Berkeley National Laboratory, and by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Geothermal Technologies, of the U.S. Department of Energy, under Contract No. DE-AC03-76SF00098. 2 i TABLE OF CONTENTS 1. INTRODUCTION ...........................................................................................................

136

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

E-Print Network (OSTI)

Multiphase pumping is a new technology used for reducing capital investments, increasing production rates, and improving recoveries in many on-shore projects. Interest is also growing in the subsea/offshore application of this technology. Multiphase 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 mass flow rates. During periods of substantial gas flow, temperature becomes the critical variable determining the performance of the pump. Without the liquid phase to remove the gas compression heat, temperatures in the discharge gas stream begin to rise causing a decrease in efficiency, a high temperature shut-in of the pump, and damage to the pump. While this behavior has been observed in lab experiments and in the field, a review of literature reveals that no mechanistic model exists for predicting the performance of a twin-screw pump under high gas volume flow conditions. Also, very few data are available under high GVF conditions. Both large-scale experiments and mechanistic modeling were performed as part of this research. This thesis models the behavior of a twin-screw multiphase pump under high gas volume fraction conditions. The model of the pump is based on fundamental principles of thermodynamic and fluid mechanics. The specific experimental tasks undertaken in this work include studying the volumetric pump performance during periods of high gas volume fractions, the observation of temperature increase with time under periods of 100% gas volume fraction and studying the effect of viscosity on high GVF performance. The results indicate that the pump can be operated during periods of 100% gas volume fractions. The volumetric efficiency of the twin-screw multiphase pump during periods of high to 100% gas volume fractions can be improved by increasing the viscosity of the process stream or by injecting high viscosity fluids into the pump casing. At 94-95% gas volume fraction the system transitions from isothermal conditions. And the system moves from isothermal to adiabatic (uncooled) conditions with time. A model has been generated that predicts temperature increase with time as a function of the key parameters of pump speed, differential pressure, mass flow rate, specific heat and slip flow. This model can be used to develop novel control philosophies for operating multiphase pumps during high gas volume fractions.

Singh, Aditya

2003-01-01T23:59:59.000Z

137

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

DOE Patents (OSTI)

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.

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

2012-07-31T23:59:59.000Z

138

The Influence of Proposed Repository Thermal Load on Multiphase Flow and Heat Transfer in the Unsaturated Zone of Yucca Mountain  

E-Print Network (OSTI)

22]. Fluid flow and heat-transfer processes in a two-phase,processes associated with multiphase flow and heat transferprocesses has also motivated development of fluid flow and heat transfer

Wu, Y.-S.; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, G.S.

2006-01-01T23:59:59.000Z

139

Oxyferryl Heme Reactivity  

NLE Websites -- All DOE Office Websites (Extended Search)

Oxyferryl Heme Reactivity Using both Radiation and Photochemical Oxyferryl Heme Reactivity Using both Radiation and Photochemical Techniques A. M. English, T. Fox, G. Tsaprailis, C. W. Fenwick, J. F. Wishart, J. T. Hazzard, and G. Tollin Adv. Chem. Ser. 254, Ch. 6, pp. 81-98 Abstract: Flash photolysis and pulse radiolysis were used to generate reductants in situ to study the electron-transfer (ET) reactivity of the FeIV=O heme centers in myoglobin and cytochrome c peroxidase. Reduction of a5RuIII groups covalently bound to surface histidines allowed intramolecular RuII --> FeIV=O ET rates to be measured. Protonation of the oxene ligand was found to be largely rate determining in myoglobin, consistent with the lack of proton donors in its heme pocket. The large distance (21-23 Ã…) between surface histidines and the heme in wild-type

140

Reactivity of Acid Generators  

NLE Websites -- All DOE Office Websites (Extended Search)

Reactivity of Acid Generators for Chemically Amplified Resists with Reactivity of Acid Generators for Chemically Amplified Resists with Low-Energy Electrons Atsuro Nakano, Takahiro Kozawa, Seiichi Tagawa, Tomasz Szreder, James F. Wishart, Toshiyuki Kai and Tsutomu Shimokawa Jpn. J. Appl. Phys., 45, L197-L200 (2006). [Find paper at the Japanese Journal of Applied Physics] Abstract: In chemically amplified resists for ionizing radiations such as electron beams and extreme ultraviolet (EUV), low-energy electrons play an important role in the pattern formation processes. The reactivity of acid generators with low-energy electrons was evaluated using solvated electrons in tetrahydrofuran, which were generated by a pulsed electron beam. The rate constants of acid generators with the solvated electrons ranged from 0.6 to 1.9 x 1011 M-1s-1

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Lattice Boltzmann Method for Multiphase Flows with High Density and Viscosity Ratios  

NLE Websites -- All DOE Office Websites (Extended Search)

Lattice Boltzmann Method for Multiphase Flows with High Density and Viscosity Ratios Lattice Boltzmann Method for Multiphase Flows with High Density and Viscosity Ratios Seckin Gokaltun, Dwayne McDaniel and David Roelant Florida International University, Miami, FL Background As a result of atomic weapons production, millions of gallons of radioactive waste was generated and stored in underground tanks at various U.S. Department of Energy sites. Department of Energy is currently in the process of transferring the waste from single shell tanks to double shell tanks. Various waste retrieval and processing methods are employed during the transfer of the waste. One such method, pulsed-air mixing, involves injection of discrete pulses of compressed air or inert gas at the bottom of the tank to produce large bubbles that rise due to buoyancy and mix the waste in the tank

142

High-Fidelity Multi-Phase Radiation Module for Modern Coal Combustion Systems  

NLE Websites -- All DOE Office Websites (Extended Search)

Task Task Description Sample calculations LBL-PMC Future Work High-Fidelity Multi-Phase Radiation Module for Modern Coal Combustion Systems Jian Cai 1 Ricardo Marquez 1 Michael F. Modest 2 1 Postdoctoral Research Associate 2 Shaffer and George Professor of Engineering University of California Merced Merced, CA 95343, USA DE-FG26-10FE0003801 May 2012 - Pittsburgh 2/17 Introduction Task Description Sample calculations LBL-PMC Future Work Radiation Challenges in Multi-Phase Reacting Flows Radiative heat transfer in high temperature combustion systems Thermal radiation becomes very important at elevated temperatures Coal and hydrocarbon fuels C n H m → H 2 O, CO 2 , CO, NO x , soot, char, ash CO 2 , H 2 O, soot, char and ash strongly emit and absorb radiative energy (lower temperature levels) Radiative effects are conveniently ignored or treated with very crude models Neglecting

143

Stochastic Finite Element Analysis for Multiphase Flow in Heterogeneous Porous Media  

E-Print Network (OSTI)

. This study is concerned with developing a two-dimensional multiphase model that simulates the movement of NAPL in heterogeneous aquifers. Heterogeneity is dealt with in a probabilistic sense by modeling the intrinsic permeability of the porous medium as a stochastic process. The deterministic finite element method is used to spatially discretize the multiphase flow equations. The intrinsic permeability is represented in the model via its Karhunen-Loeve expansion (Ghanem and Spanos, 1991). This is a computationally expedient representation of stochastic processes by means of a discrete set of random variables. Further, the nodal unknowns, water phase saturations and water phase pressures, are represented by their stochastic spectral expansions. This representation involves an orthogonal basis in the space of random variables. The basis consists of orthogonal polynomial chaoses of consecutive orders. The relative permeabilities of water and oil phases, and the capillary pressure are ex...

R. Ghanem; S. Dham

1998-01-01T23:59:59.000Z

144

LDRD final report: Physical simulation of nonisothermal multiphase multicomponent flow in porous media  

Science Conference Proceedings (OSTI)

This document reports on the accomplishments of a laboratory-directed research and development (LDRD) project whose objective was to initiate a research program for developing a fundamental understanding of multiphase multicomponent subsurface transport in heterogeneous porous media and to develop parallel processing computational tools for numerical simulation of such problems. The main achievement of this project was the successful development of a general-purpose, unstructured grid, multiphase thermal simulator for subsurface transport in heterogeneous porous media implemented for use on massively parallel (MP) computers via message-passing and domain decomposition techniques. The numerical platform provides an excellent base for new and continuing project development in areas of current interest to SNL and the DOE complex including, subsurface nuclear waste disposal and cleanup, groundwater availability and contamination studies, fuel-spill transport for accident analysis, and DNAPL transport and remediation.

Martinez, M.J.; Hopkins, P.L.; Shadid, J.N.

1997-07-01T23:59:59.000Z

145

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

Science Conference Proceedings (OSTI)

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.

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

146

Considerations for developing models of multiphase flow in deformable porous media.  

Science Conference Proceedings (OSTI)

This document summarizes research and planning for the development of a numerical simulation capability for nonisothermal multiphase, multicomponent transport in heterogeneous deformable porous materials. Particular attention is given to describing a mathematical formulation for flow in deformable media and for numerical techniques for dealing with phase transitions. A development plan is formulated to provide a computational capability motivated by current and future needs in geosystems management for energy security.

Martinez, Mario J.; Stone, Charles Michael

2008-09-01T23:59:59.000Z

147

Local volume-time averaged equations of motion for dispersed, turbulent, multiphase flows  

Science Conference Proceedings (OSTI)

In most flows of liquids and their vapors, the phases are dispersed randomly in both space and time. These dispersed flows can be described only statistically or in terms of averages. Local volume-time averaging is used here to derive a self-consistent set of equations governing momentum and energy transfer in dispersed, turbulent, multiphase flows. The empiricisms required for use with these equations are the subject of current research.

Sha, W.T.; Slattery, J.C.

1980-11-01T23:59:59.000Z

148

Reactive Power Compensating System.  

DOE Patents (OSTI)

The circuit was designed for the specific application of wind-driven induction generators. It has great potential for application in any situation where a varying reactive power load is present, such as with induction motors or generators, or for transmission network compensation.

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

1985-01-04T23:59:59.000Z

149

Reactive power compensating system  

DOE Patents (OSTI)

The reactive power of an induction machine is compensated by providing fixed capacitors on each phase line for the minimum compensation required, sensing the current on one line at the time its voltage crosses zero to determine the actual compensation required for each phase, and selecting switched capacitors on each line to provide the balance of the compensation required.

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

1987-01-01T23:59:59.000Z

150

Investigating capillary pressure and interfacial area for multiphase flow in porous media using pore-scale imaging and lattice-Boltzmann modeling.  

E-Print Network (OSTI)

??Recent advances in imaging technology and numerical modeling have greatly enhanced pore-scale investigations of multiphase flow and transport in porous media. It is now feasible… (more)

[No author

2008-01-01T23:59:59.000Z

151

Grid Shunt Reactive Power Compensation  

Science Conference Proceedings (OSTI)

This report provides essential information on transmission grid shunt reactive power compensation, with particular focus on controllable reactive power sources such as the static var controller (SVC). Applying the information presented in this report can help electric utilities planning grid shunt reactive power compensation strategies or operating shunt reactive power compensation equipment to increase grid reliability, improve grid performance and prevent costly cascading outages. The report is intende...

2008-11-26T23:59:59.000Z

152

Reactive Air Aluminization  

DOE Green Energy (OSTI)

Ferritic stainless steels and other alloys are of great interest to SOFC developers for applications such as interconnects, cell frames, and balance of plant components. While these alloys offer significant advantages (e.g., low material and manufacturing cost, high thermal conductivity, and high temperature oxidation resistance), there are challenges which can hinder their utilization in SOFC systems; these challenges include Cr volatility and reactivity with glass seals. To overcome these challenges, protective coatings and surface treatments for the alloys are under development. In particular, aluminization of alloy surfaces offers the potential for mitigating both evaporation of Cr from the alloy surface and reaction of alloy constituents with glass seals. Commercial aluminization processes are available to SOFC developers, but they tend to be costly due to their use of exotic raw materials and/or processing conditions. As an alternative, PNNL has developed Reactive Air Aluminization (RAA), which offers a low-cost, simpler alternative to conventional aluminization methods.

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

2011-10-28T23:59:59.000Z

153

Reactive Maintenance | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Reactive Maintenance Reactive Maintenance Reactive Maintenance October 7, 2013 - 9:40am Addthis Reactive maintenance follows a run-it-until-it-breaks strategy where no actions or efforts are taken to maintain equipment as intended by the manufacturer. Studies indicate this is still the predominant mode of maintenance for Federal facilities. Advantages Reactive maintenance advantages are a double-edged sword. Federal agencies following a purely reactive maintenance strategy can expect little expenditures for manpower or system upkeep until something breaks. However, systems do break. With new equipment, Federal agencies can expect minimal incidents of failure. However, older equipment often experiences higher failure incidents and costlier repairs. Other advantages of reactive maintenance are:

154

Toward a General Theory for Multiphase Turbulence Part I: Development and Gauging of the Model Equations  

SciTech Connect

A formalism for developing multiphase turbulence models is introduced by analogy to the phenomenological method used for single-phase turbulence. A sample model developed using the formalism is given in detail. The procedure begins with ensemble averaging of the exact conservation equations, with closure accomplished by using a combination of analytical and experimental results from the literature. The resulting model is applicable to a wide range of common multiphase flows including gas-solid, liquid-solid and gas-liquid (bubbly) flows. The model is positioned for ready extension to three-phase turbulence, or for use in two-phase turbulence in which one phase is accounted for in multiple size classes, representing polydispersivity. The formalism is expected to suggest directions toward a more fundamentally based theory, similar to the way that early work in single-phase turbulence has led to the spectral theory. The approach is unique in that a portion of the total energy decay rate is ascribed to each phase, as is dictated by the exact averaged equations, and results in a transport equation for energy decay rate associated with each phase. What follows is a straightforward definition of a turbulent viscosity for each phase, and accounts for the effect of exchange of fluctuational energy among phases on the turbulent shear viscosity. The model also accounts for the effect of slip momentum transfer among the phases on the production of turbulence kinetic energy and on the tensor character of the Reynolds stress. Collisional effects, when appropriate, are included by superposition. The model reduces to a standard form in limit of a single, pure material, and is expected to do a credible job of describing multiphase turbulent flows in a wide variety of regimes using a single set of coefficients.

B. A. Kashiwa; W. B. VanderHeyden

2000-12-01T23:59:59.000Z

155

Characterizing Moisture Content within Landfills  

NLE Websites -- All DOE Office Websites (Extended Search)

for fluid flow measurements 1 3 CO 2 injection Laboratory Studies of Non-isothermal and Multiphase Fluid Flow and Transport in Fractured Porous Rocks Temco triaxial cell with P&S...

156

Application of automatic differentiation for the simulation of nonisothermal, multiphase flow in geothermal reservoirs  

DOE Green Energy (OSTI)

Simulation of nonisothermal, multiphase flow through fractured geothermal reservoirs involves the solution of a system of strongly nonlinear algebraic equations. The Newton-Raphson method used to solve such a nonlinear system of equations requires the evaluation of a Jacobian matrix. In this paper we discuss automatic differentiation (AD) as a method for analytically computing the Jacobian matrix of derivatives. Robustness and efficiency of the AD-generated derivative codes are compared with a conventional derivative computation approach based on first-order finite differences.

Kim, Jong G.; Finsterle, Stefan

2002-01-08T23:59:59.000Z

157

Performance Evaluation and CFD Simulation of Multiphase Twin-Screw Pumps  

E-Print Network (OSTI)

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 work focuses on the experimental and numerical analysis of twin-screw pumps for different operating conditions. Experimental evaluation aims to understand steady state and transient behavior of twin-screw pumps. Detailed steady state evaluation helped form better understanding of twin-screw pumps under different operating conditions. A comparative study of twin-screw pumps and compressors contradicted the common belief that compressor efficiency is better than the efficiency of twin-screw pumps. Transient analysis at high GVF helped incorporate necessary changes in the design of sealflush recirculation loop to improve the efficiency of the pump. The effect of viscosity of the sealflush fluid at high GVF on pump performance was studied. Volumetric efficiency was found to be decreased with increase in viscosity. Flow visualization was aimed to characterize phase distribution along cavities and clearances at low to high GVF. Dynamic pressure variation was studied along the axis of the screw which helped correlate the GVF, velocity and pressure distribution. Complicated fluid flow behavior due to enclosed fluid pockets and interconnecting clearances makes it difficult to numerically simulate the pump. Hence design optimization and performance prediction incorporates only analytical approach and experimental evaluation. Current work represents an attempt to numerically simulate a multiphase twin-screw pump as a whole. Single phase 3D CFD simulation was performed for different pressure rise. The pressure and velocity profile agreed well with previous studies. Results are validated using an analytical approach as well as experimental data. A two-phase CFD simulation was performed for 50% GVF. An Eulerian approach was employed to evaluate multiphase flow behavior. Pressure, velocity, temperature and GVF distributions were successfully predicted using CFD simulation. Bubble size was found to be most dominant parameter, significantly affecting phase separation and leakage flow rate. Better phase separation was realized with increased bubble size, which resulted in decrease in leakage flow rate. CFD results agreed well with experimental data for the bubble size higher than 0.08 mm.

Patil, Abhay

2013-08-01T23:59:59.000Z

158

Triangular flow in heavy ion collisions in a multiphase transport model  

E-Print Network (OSTI)

We obtain a new set of parameters in a multiphase transport (AMPT) model that are able to describe both the charged particle multiplicity density and the elliptic flow measured in Au + Au collisions at center-of-mass energy root(S)NN = 200 GeV at the Relativistic Heavy Ion Collider, 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 dihadron azimuthal correlations in both central and midcentral collisions.

Xu, Jun; Ko, Che Ming.

2011-01-01T23:59:59.000Z

159

Adaptive fully implicit multi-scale finite-volume method for multi-phase flow and transport in heterogeneous porous media  

Science Conference Proceedings (OSTI)

We describe a sequential fully implicit (SFI) multi-scale finite volume (MSFV) algorithm for nonlinear multi-phase flow and transport in heterogeneous porous media. The method extends the recently developed multiscale approach, which is based on an IMPES ... Keywords: coupled flow and transport, finite-volume, heterogeneous porous media, immiscible multi-phase flow, multiscale methods, numerical simulation

P. Jenny; S. H. Lee; H. A. Tchelepi

2006-09-01T23:59:59.000Z

160

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

DOE Patents (OSTI)

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.

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

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
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161

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

Science Conference Proceedings (OSTI)

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.

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

2008-01-01T23:59:59.000Z

162

Multi-Phase CFD Modeling of Solid Sorbent Carbon Capture System  

Science Conference Proceedings (OSTI)

Computational fluid dynamics (CFD) simulations are used to investigate a low temperature post-combustion carbon capture reactor. The CFD models are based on a small scale solid sorbent carbon capture reactor design from ADA-ES and Southern Company. The reactor is a fluidized bed design based on a silica-supported amine sorbent. CFD models using both Eulerian-Eulerian and Eulerian-Lagrangian multi-phase modeling methods are developed to investigate the hydrodynamics and adsorption of carbon dioxide in the reactor. Models developed in both FLUENT® and BARRACUDA are presented to explore the strengths and weaknesses of state of the art CFD codes for modeling multi-phase carbon capture reactors. The results of the simulations show that the FLUENT® Eulerian-Lagrangian simulations (DDPM) are unstable for the given reactor design; while the BARRACUDA Eulerian-Lagrangian model is able to simulate the system given appropriate simplifying assumptions. FLUENT® Eulerian-Eulerian simulations also provide a stable solution for the carbon capture reactor given the appropriate simplifying assumptions.

Ryan, Emily M.; DeCroix, David; Breault, Ronald W.; Xu, Wei; Huckaby, E. D.; Saha, Kringan; Darteville, Sebastien; Sun, Xin

2013-07-30T23:59:59.000Z

163

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

E-Print Network (OSTI)

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. However, the special design of the impeller blades of the MVP ESP enables it to handle higher GVF. Dynamic behavior of the multiphase flow is studied experimentally and theoretically for this pump for the first time. In this work, a Computational Fluid Dynamics (CFD) simulation of an entire pump and detailed experimental analysis are performed. Meshing and CFD simulations are performed using the commercially available software ANSYS Fluent. An experimental facility has been designed and constructed to test the pump at different operating conditions. The pump is modeled and tested at two speeds; 3300 and 3600 rpm, using air-water mixtures with GVFs of 0, 5, 10, 25, 32 and 35%. The flow loop is controlled to produce different suction pressures up to 300psi. Pump pressure head is used to validate the CFD model for both single and two phase flows. Single phase CFD model was validated at 100 psi inlet pressure, while two phase models were validated at 200 psi inlet pressure. CFD simulations can predict the behavior of the pump at different speeds, flow rates, GVFs, and inlet pressures. Different diffuser designs are studied and simulated to improve the multistage pump performance. Enhanced diffuser designs increased the pump pressure head to up to 3.2%.

Rasmy Marsis, Emanuel 1983-

2012-12-01T23:59:59.000Z

164

Reactive rules on the web  

Science Conference Proceedings (OSTI)

Reactive rules are used for programming rule-based, reactive systems, which have the ability to detect events and respond to them automatically in a timely manner. Such systems are needed on the Web for bridging the gap between the existing, passive ...

Bruno Berstel; Philippe Bonnard; François Bry; Michael Eckert; Paula-Lavinia P?trânjan

2007-09-01T23:59:59.000Z

165

Multi-organ segmentation from multi-phase abdominal CT via 4D graphs using enhancement, shape and location optimization  

Science Conference Proceedings (OSTI)

The interpretation of medical images benefits from anatomical and physiological priors to optimize computer-aided diagnosis (CAD) applications. Diagnosis also relies on the comprehensive analysis of multiple organs and quantitative measures of soft tissue. ... Keywords: 4D graph, enhancement, multi-phase CT, segmentation, shape

Marius George Linguraru; John A. Pura; Ananda S. Chowdhury; Ronald M. Summers

2010-09-01T23:59:59.000Z

166

Fast computation of multiphase flow in porous media by implicit discontinuous Galerkin schemes with optimal ordering of elements  

Science Conference Proceedings (OSTI)

We present a family of implicit discontinuous Galerkin schemes for purely advective multiphase flow in porous media in the absence of gravity and capillary forces. To advance the solution one time step, one must solve a discrete system of nonlinear equations. ... Keywords: Implicit upwind scheme, Porous media flow, Topological sorting

Jostein R. Natvig; Knut-Andreas Lie

2008-12-01T23:59:59.000Z

167

A Tariff for Reactive Power  

DOE Green Energy (OSTI)

Two kinds of power are required to operate an electric power system: real power, measured in watts, and reactive power, measured in volt-amperes reactive or VARs. Reactive power supply is one of a class of power system reliability services collectively known as ancillary services, and is essential for the reliable operation of the bulk power system. Reactive power flows when current leads or lags behind voltage. Typically, the current in a distribution system lags behind voltage because of inductive loads such as motors. Reactive power flow wastes energy and capacity and causes voltage droop. To correct lagging power flow, leading reactive power (current leading voltage) is supplied to bring the current into phase with voltage. When the current is in phase with voltage, there is a reduction in system losses, an increase in system capacity, and a rise in voltage. Reactive power can be supplied from either static or dynamic VAR sources. Static sources are typically transmission and distribution equipment, such as capacitors at substations, and their cost has historically been included in the revenue requirement of the transmission operator (TO), and recovered through cost-of-service rates. By contrast, dynamic sources are typically generators capable of producing variable levels of reactive power by automatically controlling the generator to regulate voltage. Transmission system devices such as synchronous condensers can also provide dynamic reactive power. A class of solid state devices (called flexible AC transmission system devices or FACTs) can provide dynamic reactive power. One specific device has the unfortunate name of static VAR compensator (SVC), where 'static' refers to the solid state nature of the device (it does not include rotating equipment) and not to the production of static reactive power. Dynamic sources at the distribution level, while more costly would be very useful in helping to regulate local voltage. Local voltage regulation would reduce system losses, increase circuit capacity, increase reliability, and improve efficiency. Reactive power is theoretically available from any inverter-based equipment such as photovoltaic (PV) systems, fuel cells, microturbines, and adjustable-speed drives. However, the installation is usually only economical if reactive power supply is considered during the design and construction phase. In this report, we find that if the inverters of PV systems or the generators of combined heat and power (CHP) systems were designed with capability to supply dynamic reactive power, they could do this quite economically. In fact, on an annualized basis, these inverters and generators may be able to supply dynamic reactive power for about $5 or $6 per kVAR. The savings from the local supply of dynamic reactive power would be in reduced losses, increased capacity, and decreased transmission congestion. The net savings are estimated to be about $7 per kVAR on an annualized basis for a hypothetical circuit. Thus the distribution company could economically purchase a dynamic reactive power service from customers for perhaps $6/kVAR. This practice would provide for better voltage regulation in the distribution system and would provide an alternate revenue source to help amortize the cost of PV and CHP installations. As distribution and transmission systems are operated under rising levels of stress, the value of local dynamic reactive supply is expected to grow. Also, large power inverters, in the range of 500 kW to 1 MW, are expected to decrease in cost as they become mass produced. This report provides one data point which shows that the local supply of dynamic reactive power is marginally profitable at present for a hypothetical circuit. We expect that the trends of growing power flow on the existing system and mass production of inverters for distributed energy devices will make the dynamic supply of reactive power from customers an integral component of economical and reliable system operation in the future.

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

2008-07-01T23:59:59.000Z

168

Federal Energy Management Program: Reactive Maintenance  

NLE Websites -- All DOE Office Websites (Extended Search)

Reactive Reactive Maintenance to someone by E-mail Share Federal Energy Management Program: Reactive Maintenance on Facebook Tweet about Federal Energy Management Program: Reactive Maintenance on Twitter Bookmark Federal Energy Management Program: Reactive Maintenance on Google Bookmark Federal Energy Management Program: Reactive Maintenance on Delicious Rank Federal Energy Management Program: Reactive Maintenance on Digg Find More places to share Federal Energy Management Program: Reactive Maintenance on AddThis.com... Sustainable Buildings & Campuses Operations & Maintenance Federal Requirements Program Management Commissioning Metering Computerized Maintenance Management Systems Maintenance Types Reactive Preventive Predictive Reliability-Centered Major Equipment Types

169

Non-Isothermal Creep Behavior of a Second Generation Ni-Based ...  

Science Conference Proceedings (OSTI)

misfit alloys and development of stable dislocation networks at the ?/?' interfaces. However ... power to maintain the helicopter airborne. In this case, the high ... of the ?' reinforcing phase and induces a severe loss in mechanical properties.

170

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

E-Print Network (OSTI)

generation during over- charge. Since the metal hydride material gradually loses capacity through usage due KOH solution, which has good electric conductivity for a wide range of temperatures. Some Li

171

Multi-symplectic relative equilibria, multi-phase wavetrains and coupled NLS equations  

E-Print Network (OSTI)

The paper begins with a geometric formulation of 2-phase wavetrain solutions of coupled nonlinear Schrodinger equations. It is shown that these solutions come in natural 4-parameter families, associated with symmetry, and a geometric instability condition can be deduced from the parameter structure which generalizes Roskes' instability criterion. It is then shown that this geometric structure is universal in the sense that it does not depend on the particular equation, only on the structure of the equations. The theory also extends to the case without symmetry, where small divisors may be present, but gives a new formal geometric framework for multi-phase wavetrains. 1 Introduction This paper has three interrelated parts. It starts by considering a system of coupled nonlinear Schrodinger (cNLS) equations as motivation. Coupled NLS equations are model PDEs which appear in a wide range of wave phenomena, including plasma physics, optics and water waves. The cNLS equations have a basic...

Thomas J. Bridges; Fiona E. Laine-pearson

2000-01-01T23:59:59.000Z

172

Multicomponent, Multiphase Thermodynamics of Swelling Porous Media with Electroquasistatics: I. Macroscale Field Equations  

E-Print Network (OSTI)

A systematic development of the macroscopic field equations (conservation of mass, linear and angular momentum, energy, and Maxwell’s equations) for a multiphase, multicomponent medium is presented. It is assumed that speeds involved are much slower than the speed of light and that the magnitude of the electric field significantly dominates over the magnetic field so that the electroquasistatic form of Maxwell’s equations applies. A mixture formulation is presented for each phase and then averaged to obtain the macroscopic formulation. Species electric fields are considered, however it is assumed that it is the total electric field which contributes to the electrically induced forces and energy. The relationships between species and bulk phase variables and the macroscopic and microscopic variables are given explicitly. The resulting field equations are of relevance to many practical applications including, but not limited to, swelling clays (smectites), biopolymers, biological membranes, pulsed electrophoresis, and chromatography.

Lynn Schreyer Bennethum; John H. Cushman

2001-01-01T23:59:59.000Z

173

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

DOE Green Energy (OSTI)

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.

Pruess, K.

1991-05-01T23:59:59.000Z

174

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

Science Conference Proceedings (OSTI)

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}.

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

2006-08-01T23:59:59.000Z

175

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

Science Conference Proceedings (OSTI)

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.

Yortsos, Yanis C.

2001-08-07T23:59:59.000Z

176

Progress in the Development of Compressible, Multiphase Flow Modeling Capability for Nuclear Reactor Flow Applications  

Science Conference Proceedings (OSTI)

In nuclear reactor safety and optimization there are key issues that rely on in-depth understanding of basic two-phase flow phenomena with heat and mass transfer. Within the context of multiphase flows, two bubble-dynamic phenomena – boiling (heterogeneous) and flashing or cavitation (homogeneous boiling), with bubble collapse, are technologically very important to nuclear reactor systems. The main difference between boiling and flashing is that bubble growth (and collapse) in boiling is inhibited by limitations on the heat transfer at the interface, whereas bubble growth (and collapse) in flashing is limited primarily by inertial effects in the surrounding liquid. The flashing process tends to be far more explosive (and implosive), and is more violent and damaging (at least in the near term) than the bubble dynamics of boiling. However, other problematic phenomena, such as crud deposition, appear to be intimately connecting with the boiling process. In reality, these two processes share many details.

R. A. Berry; R. Saurel; F. Petitpas; E. Daniel; O. Le Metayer; S. Gavrilyuk; N. Dovetta

2008-10-01T23:59:59.000Z

177

Reactivity of heat treated chars  

DOE Green Energy (OSTI)

Reactivities of a number of chars produced from American coals varying in rank from lignite to anthracite have been measured in air, CO/sub 2/, steam and H/sub 2/. The variables chosen for the study were: rank of the parent coal, inorganic matter content, particle size, reaction temperature and pressure as well as heat treatment conditions used during char preparation. In all gasification atmospheres studied, reactivity plots for different chars are essentially of the same general shape and have three distinct regions. The reaction rate first increases slowly with time. The plot then goes through a maximum in slope, followed by a lengthy region of decreasing slope as burn-off approaches 100 percent. The shape of the burn-off curves can be explained on the basis of what is known about the development of porosity and surface area in microporous chars as they undergo gasification. Using an adjustable time parameter, equations have been developed which successfully correlate the reactivity data. Char reactivity decreases, in general, with increase in rank of the parent coal. Reactivities of chars in air, CO/sub 2/ and steam increase over 150-fold in going from a low volatile bituminous to a lignite parent coal; the spread in char reactivities in H/sub 2/ is only 30-fold. Removal of inorganic matter from coal precursors prior to their charring or from chars produced from the raw coals has a marked effect on char reactivity and surface area. Removal of inorganic matter (by acid washing) decreases, in general, reactivity of chars produced from lower rank coals, whereas reactivities of chars derived from higher rank coals increase.

Mahajan, O. P.; Walker, Jr., P. L.

1977-01-01T23:59:59.000Z

178

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

SciTech Connect

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.

Moses Bogere

2011-08-31T23:59:59.000Z

179

Method and system for measuring multiphase flow using multiple pressure differentials  

DOE Patents (OSTI)

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.

Fincke, James R. (Idaho Falls, ID)

2001-01-01T23:59:59.000Z

180

Pore-scale imaging and lattice Boltzmann modeling of single- and multi-phase flow in fractured and mixed-wet permeable media.  

E-Print Network (OSTI)

??Three investigations of pore-scale single-phase and multiphase flow in fractured porous media and mixed-wet porous media are presented here. With an emphasis on validating and… (more)

Landry, Christopher

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Experimental assessment and modeling of organic compound interphase mass-transfer rates in multiphase subsurface systems. Progress report  

SciTech Connect

During the initial eight month period of this grant, work has been conducted on all facets of the project. Significant progress has been made in the design, construction and testing of the experimental apparatus. Investigation of methods for characterizing the physical forms of non-aqueous phase liquid (NAPL) residuals (globules or blobs) has led to a narrowing of possible approaches. Development of a numerical simulator that accomodates multiphase transport with mass transfer rate interactions is well underway.

Weber, W.J. Jr.; Abriola, L.M.

1990-03-15T23:59:59.000Z

182

Investigation of a Multiphase Twin-screw Pump Operating at High Gas Volume Fractions  

E-Print Network (OSTI)

The use of twin-screw pumps for moving fluids is not new technology but its application to wet gas compression (high gas volume fraction [GVF]) is still considered relatively new. There are many advantages for using twin-screw pumps for oil field applications; three of the immediate improvements include reducing hardware costs, reducing well bore pressure, and producing a pressure boost to move the product to a central collection facility. While there are many advantages to using twin-screw pumps in wet gas applications, there are some problems that have been encountered while operating at high GVFs. When operating at high GVF, over 95 percent twin-screw pumps experience a severe loss of efficiency and an increase of operating temperature. A common way to increase the efficiency while operating in the high GVF range includes adding a liquid recirculation system where a portion of liquid is stored downstream of the pump and is injected into the pump inlet. These systems lower the effective GVF of the multiphase fluid below 95 percent in order to increase the pump efficiency. The first objective is to characterize the performance of a twin-screw pump fitted with a liquid recirculation system while operating under high GVF conditions. The second objective is to investigate the transient heat rise associated with high GVF operation. While traditional twin-screw pumps can be fitted with a liquid recirculation system to allow them to operate under high GVF conditions the pumps themselves are not optimized for wet gas compression and still suffer performance penalties. The results of this investigation show that the liquid recirculation system can allow the pump to operate under high GVF but the heat added to the system reduces the systems efficiency. Without a method of removing the heat generated in the pumping process the pump will not run at its optimal efficiency. The following investigation provides recommendations for further research in area of multiphase pumping using twin-screw pumps based on the characterization and transient studies provided in this thesis.

Kroupa, Ryan Daniel

2011-05-01T23:59:59.000Z

183

Studies on multi-phase equilibrium separation of hydrocarbon/water systems  

E-Print Network (OSTI)

Equations of State (EOS) have been used successfully in compositional simulators to describe phase behavior of reservoir crude and gas condensates without water. The three-phase behavior of water/reservoir crude oils both at reservoir and steam flooding temperature has not yet been successfully predicted by an EOS. Recent publications show that incorporation of the association concept into simple cubic equations such as Peng-Robinson EOS significantly improves phase behavior prediction of water/hydrocarbon and nonhydrate systems, but there are still some numerical difficulties in the pre-diction of three phase flash equilibria. In this thesis we presented, an efficient procedure that will help us eliminate common numerical difficulties in predicting three-phase equilibria for systems containing water, and simplify the programming technique. This scheme checks the existence of three-phase flash at given reservoir conditions, and if three-phase flash (vapor-oleic-aqueous) doesn't exist, it automatically switches to check correct type of two-phase flash (vapor-oleic, vapor-aqueous, or oleic-aqueous). This convergence scheme is used in an EOS-simulator (VLLESIM), which uses nine different EOS's and van der Waals mixing rules, to accurately describe multi-phase equilibrium separation of hydrocarbon/water systems. VLLESIM will be validated with literature data and experimental results obtained from two different experimental setups, for different multi-component hydrocarbon/water systems, for hydrocarbon component varying from C6 to C20. PVT-VLLE apparatus can provide on-line compositional analysis and phase volumes of all equilibrium phases for temperatures up to 350 'F and an Isochoric Steam Distillation Cell (ISDC) can provide only vapor phase compositions, but it can be used up to 500 'F. VLLESIM will then be used to study the effect of temperature, pressure and molecular weight of hydrocarbon components on multiphase equilibria of different hydrocarbon/water systems. Detailed analysis is also provided in this thesis, of the effect of increasing concentration of different hydrocarbon components on the size of the three-phase region for ranges of temperature and pressure mostly prevalent under reservoir conditions.

Chawla, Inderjit Singh

1995-01-01T23:59:59.000Z

184

Ensemble phase averaging equations for multiphase flows in porous media, part I: the bundle-of-tubes model  

Science Conference Proceedings (OSTI)

A bundle-of-tubes construct is used as a model system to study ensemble averaged equations for multiphase flow in a porous material. Momentum equations for the fluid phases obtained from the method are similar to Darcy's law, but with additional terms. We study properties of the additional terms, and the conditions under which the averaged equations can be approximated by the diffusion model or the extended Darcy's law as often used in models for multiphase flows in porous media. Although the bundle-of-tubes model is perhaps the simplest model for a porous material, the ensemble averaged equation technique developed in this paper assumes the very same form in more general treatments described in Part 2 of the present work (Zhang 2009). Any model equation system intended for the more general cases must be understood and tested first using simple models. The concept of ensemble phase averaging is dissected here in physical terms, without involved mathematics through its application to the idealized bundle-of-tubes model for multiphase flow in porous media.

Yang, Dali [Los Alamos National Laboratory; Zhang, Duan [Los Alamos National Laboratory; Currier, Robert [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

185

DETERMINATION OF SPECIFIC NEUTRONIC REACTIVITY  

DOE Patents (OSTI)

A method is given for production-line determination of the specific neutronic reactivity of such objects as individual nuclear fuel or neutron absorber elements and is notable for rapidity and apparatus simplicity. The object is incorporated in a slightly sub-critical chain fission reactive assembly having a discrete neutron source, thereby establishing a K/sub eff/ within the crucial range of 0.95 to 0.995. The range was found to afford, uniquely, flux- transient damped response in a niatter of seconds simultaneously with acceptable analytical sensitivity. The resulting neutron flux measured at a situs spaced from both object and source within the assembly serves as a calibrable indication of said reactivity.

Dessauer, G.

1960-05-10T23:59:59.000Z

186

Multiphase Modeling of Flow, Transport, and Biodegradation in a Mesoscale Landfill Bioreactor  

DOE Green Energy (OSTI)

The need to control gas and leachate production and minimize refuse volume in municipal solid waste landfills has motivated the development of landfill simulation models to predict and design optimal treatment processes. We have developed a multiphase and multicomponent nonisothermal module called T2LBM for the three-dimensional TOUGH2 flow and transport simulator. T2LBM can be used to simulate aerobic or anaerobic biodegradation of municipal solid waste and the associated flow and transport of gas and liquid through the refuse mass. Acetic acid is used as a proxy for all biodegradable substrates in the refuse. T2LBM incorporates a Monod kinetic rate law for the biodegradation of acetic acid by either aerobic or anaerobic microbes as controlled by the local oxygen concentration. We have verified the model against published data, and applied it to our own mesoscale laboratory aerobic landfill bioreactor experiments. We observe spatial variability of flow and biodegradation consistent with permeability heterogeneity and the geometry of the radial grid. The model is capable of matching results of a shut-in test where the respiration of the system is measured over time.

Oldenburg, Curtis M.; Borglin, Sharon E.; Hazen, Terry C.

2002-02-01T23:59:59.000Z

187

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

E-Print Network (OSTI)

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.

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

2013-01-21T23:59:59.000Z

188

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

E-Print Network (OSTI)

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.

Krummel, Amber T; Münster, Stefan; Weitz, David A; 10.1002/aic.14005

2013-01-01T23:59:59.000Z

189

Development of Approach to Estimate Volume Fraction of Multiphase Material Using Dielectrics  

E-Print Network (OSTI)

Most engineering as well as pavement materials are composites composed of two or more components to obtain a variety of solid properties to support internal and external loading. The composite materials rely on physical or chemical properties and volume fraction of each component. While the properties can be identified easily, the volume fraction is hard to be estimated due to the volumetric variation during the performance in the field. Various test procedures have been developed to measure the volume fractions; however, they depend on subjective determination and judgment. As an alternative, electromagnetic technique using dielectric constant was developed to estimate the volume fraction. Empirical and mechanistic approaches were used to relate the dielectric constant and volume fraction. While the empirical models are not very accurate in all cases, the mechanistic models require assumptions of constituent dielectric constants. For those reasons, the existing approaches might produce less accurate estimate of volume fraction. In this study, a mechanistic-based approach using the self consistent scheme was developed to be applied to multiphase materials. The new approach was based on calibrated dielectric constant of components to improve results without any assumptions. Also, the system identification was used iteratively to solve for dielectric parameters and volume fraction at each step. As the validation performed to verify the viability of the new approach using soil mixture and portland cement concrete, it was found that the approach has produced a significant improvement in the accuracy of the estimated volume fraction.

Lee, Sang Ick

2010-05-01T23:59:59.000Z

190

Treating water-reactive wastes  

DOE Green Energy (OSTI)

Some compounds and elements, such as lithium hydride, magnesium, sodium, and calcium react violently with water to generate much heat and produce hydrogen. The hydrogen can ignite or even form an explosive mixture with air. Other metals may react rapidly only if they are finely divided. Some of the waste produced at Los Alamos National Laboratory includes these metals that are contaminated with radioactivity. By far the greatest volume of water-reactive waste is lithium hydride contaminated with depleted uranium. Reactivity of the water-reactive wastes is neutralized with an atmosphere of humid nitrogen, which prevents the formation of an explosive mixture of hydrogen and air. When we adjust the temperature of the nitrogen and the humidifier, the nitrogen can be more or less humid, and the rate of reaction can be adjusted and controlled. Los Alamos has investigated the rates of reaction of lithium hydride as a function of the temperature and humidity, and, as anticipated, they in with in temperature and humidity. Los Alamos will investigate other variables. For example, the nitrogen flow will be optimized to conserve nitrogen and yet keep the reaction rates high. Reaction rates will be determined for various forms of lithium waste, from small chips to powder. Bench work will lead to the design of a skid-mounted process for treating wastes. Other water-reactive wastes will also be investigated.

Lussiez, G.W.

1993-01-01T23:59:59.000Z

191

Treating water-reactive wastes  

DOE Green Energy (OSTI)

Some compounds and elements, such as lithium hydride, magnesium, sodium, and calcium react violently with water to generate much heat and produce hydrogen. The hydrogen can ignite or even form an explosive mixture with air. Other metals may react rapidly only if they are finely divided. Some of the waste produced at Los Alamos National Laboratory includes these metals that are contaminated with radioactivity. By far the greatest volume of water-reactive waste is lithium hydride contaminated with depleted uranium. Reactivity of the water-reactive wastes is neutralized with an atmosphere of humid nitrogen, which prevents the formation of an explosive mixture of hydrogen and air. When we adjust the temperature of the nitrogen and the humidifier, the nitrogen can be more or less humid, and the rate of reaction can be adjusted and controlled. Los Alamos has investigated the rates of reaction of lithium hydride as a function of the temperature and humidity, and, as anticipated, they in with in temperature and humidity. Los Alamos will investigate other variables. For example, the nitrogen flow will be optimized to conserve nitrogen and yet keep the reaction rates high. Reaction rates will be determined for various forms of lithium waste, from small chips to powder. Bench work will lead to the design of a skid-mounted process for treating wastes. Other water-reactive wastes will also be investigated.

Lussiez, G.W.

1993-05-01T23:59:59.000Z

192

Definition: Reactive Power | Open Energy Information  

Open Energy Info (EERE)

Reactive Power Reactive Power Jump to: navigation, search Dictionary.png Reactive Power The portion of electricity that establishes and sustains the electric and magnetic fields of alternating-current equipment. Reactive power must be supplied to most types of magnetic equipment, such as motors and transformers. It also must supply the reactive losses on transmission facilities. Reactive power is provided by generators, synchronous condensers, or electrostatic equipment such as capacitors and directly influences electric system voltage. It is usually expressed in kilovars (kvar) or megavars (Mvar).[1] View on Wikipedia Wikipedia Definition In electric power transmission and distribution, volt-ampere reactive (var) is a unit used to measure reactive power in an AC electric

193

Particle Swarm Optimization Based Reactive Power Optimization  

E-Print Network (OSTI)

Reactive power plays an important role in supporting the real power transfer by maintaining voltage stability and system reliability. It is a critical element for a transmission operator to ensure the reliability of an electric system while minimizing the cost associated with it. The traditional objectives of reactive power dispatch are focused on the technical side of reactive support such as minimization of transmission losses. Reactive power cost compensation to a generator is based on the incurred cost of its reactive power contribution less the cost of its obligation to support the active power delivery. In this paper an efficient Particle Swarm Optimization (PSO) based reactive power optimization approach is presented. The optimal reactive power dispatch problem is a nonlinear optimization problem with several constraints. The objective of the proposed PSO is to minimize the total support cost from generators and reactive compensators. It is achieved by maintaining the whole system power loss as minimum...

Sujin, P R; Linda, M Mary

2010-01-01T23:59:59.000Z

194

Engine combustion control via fuel reactivity stratification  

Science Conference Proceedings (OSTI)

A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter. By appropriately choose the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot).

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

2013-12-31T23:59:59.000Z

195

Reactive and Catalytic Air Purification Materials - Energy ...  

Biomass and Biofuels; Building Energy Efficiency; Electricity Transmission; ... Target selectivity can be controlled through selection of reactive components.

196

Directional Reactive Power Ground Plane Transmission  

Directional Reactive Power Ground Plane Transmission Technology Summary ... The invention can transmit electrical power through the surface of the ...

197

Partnering Today: Technology Transfer Highlights Reactive ...  

THE LLNL TECHNOLOGY COMPANY PRODUCT Partnering Today: Technology Transfer Highlights Reactive NanoTechnologies Inc.: Temperature-controlled Precision Bonding

198

Gamma Survey of a Permeable Reactive Barrier at Monticello, Utah...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Gamma Survey of a Permeable Reactive Barrier at Monticello, Utah Gamma Survey of a Permeable Reactive Barrier at Monticello, Utah Gamma Survey of a Permeable Reactive Barrier at...

199

Permeable Reactive Barriers | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Permeable Reactive Barriers Permeable Reactive Barriers Permeable Reactive Barriers Permeable Reactive Barrier Field Projects Durango, Colorado DOE installed a PRB in October 1995 to treat ground water from a uranium mill tailings disposal site at Durango, Colorado Read more Cañon City, Colorado ESL personnel conduct tests and help evaluate performance at other PRB sites, such as Cotter Corporation's Cañon City site in Colorado. Read more Monticello, Utah Installation of a PRB hydraulically downgradient of the Monticello, Utah, millsite was completed June 30, 1999, as an Interim Remedial Action. Read more A permeable reactive barrier (PRB) is a zone of reactive material placed underground to intercept and react with a contaminant plume in ground water. Typically, PRBs are emplaced by replacing soils with reactive

200

A coupled THC model of the FEBEX in situ test with bentonite swelling and chemical and thermal osmosis  

E-Print Network (OSTI)

of geological porous media with multiphase flow: theory andmultiphase flow and reactive transport in deformable porousisothermal multiphase flow and reactive transport in porous

Zheng, L.

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Comprehensive Approaches to Multiphase Flows in Geophysics - Application to nonisothermal, nonhomogenous, unsteady, large-scale, turbulent dusty clouds I. Hydrodynamic and Thermodynamic RANS and LES Models  

Science Conference Proceedings (OSTI)

The objective of this manuscript is to fully derive a geophysical multiphase model able to ''accommodate'' different multiphase turbulence approaches; viz., the Reynolds Averaged Navier-Stokes (RANS), the Large Eddy Simulation (LES), or hybrid RANSLES. This manuscript is the first part of a larger geophysical multiphase project--lead by LANL--that aims to develop comprehensive modeling tools for large-scale, atmospheric, transient-buoyancy dusty jets and plume (e.g., plinian clouds, nuclear ''mushrooms'', ''supercell'' forest fire plumes) and for boundary-dominated geophysical multiphase gravity currents (e.g., dusty surges, diluted pyroclastic flows, dusty gravity currents in street canyons). LES is a partially deterministic approach constructed on either a spatial- or a temporal-separation between the large and small scales of the flow, whereas RANS is an entirely probabilistic approach constructed on a statistical separation between an ensemble-averaged mean and higher-order statistical moments (the so-called ''fluctuating parts''). Within this specific multiphase context, both turbulence approaches are built up upon the same phasic binary-valued ''function of presence''. This function of presence formally describes the occurrence--or not--of any phase at a given position and time and, therefore, allows to derive the same basic multiphase Navier-Stokes model for either the RANS or the LES frameworks. The only differences between these turbulence frameworks are the closures for the various ''turbulence'' terms involving the unknown variables from the fluctuating (RANS) or from the subgrid (LES) parts. Even though the hydrodynamic and thermodynamic models for RANS and LES have the same set of Partial Differential Equations, the physical interpretations of these PDEs cannot be the same, i.e., RANS models an averaged field, while LES simulates a filtered field. In this manuscript, we also demonstrate that this multiphase model fully fulfills the second law of thermodynamics and fulfills the necessary requirements for a well-posed initial-value problem. In the next manuscripts, we will further develop specific closures for multiphase RANS, LES, and hybrid-LES.

S. Dartevelle

2005-09-05T23:59:59.000Z

202

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

DOE Green Energy (OSTI)

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.

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

2008-11-01T23:59:59.000Z

203

Reactive Transport and Coupled THM Processes in Engineering Barrier Systems (EBS)  

E-Print Network (OSTI)

Sorption of Long-Lived Radionuclides Cesium-134, Strontium-term retardation of radionuclide release. EBS is involved inas heat release due to radionuclide decay, multiphase flow (

Steefel, Carl

2010-01-01T23:59:59.000Z

204

Benchmarks for Quantifying Fuel Reactivity Depletion Uncertainty  

Science Conference Proceedings (OSTI)

Analytical methods, described in this report, are used to systematically determine experimental fuel sub-batch reactivities as a function of burnup. Fuel sub-batch reactivities are inferred using more than 600 in-core pressurized water reactor (PWR) flux maps taken during 44 cycles of operation at the Catawba and McGuire nuclear power plants. The analytical methods systematically search for fuel sub-batch reactivities that minimize differences between measured and computed reaction rates, using Studsvik ...

2011-08-08T23:59:59.000Z

205

Rejuvenating Permeable Reactive Barriers by Chemical Flushing  

Energy.gov (U.S. Department of Energy (DOE))

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

206

ENGINE COMBUSTION CONTROL VIA FUEL REACTIVITY ...  

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 ...

207

Electrochemistry of Enargite: Reactivity in Alkaline Solutions  

Science Conference Proceedings (OSTI)

The reactivity of enargite samples from Montana, US and Quiruvilca, Peru were studied under alkaline conditions, pH range of 8-13, using a cyclic voltammetry ...

208

Reactive Air Aluminizing - Energy Innovation Portal  

Reactive Air Aluminizing is a process for applying a protective coating on steel components in solid oxide fuel ... Building Energy Efficiency; ...

209

Reactive Air Aluminizing - Energy Innovation Portal  

Reactive Air Aluminizing is a process for applying a protective coating on steel components in solid oxide fuel cells and other high temperature electrochemical devices.

210

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

SciTech Connect

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.

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

2012-04-18T23:59:59.000Z

211

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

DOE Patents (OSTI)

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.

Ortiz, M.G.

1998-02-10T23:59:59.000Z

212

Theoretical and experimental analysis of a multiphase screw pump, handling gas-liquid mixtures with very high gas volume fractions  

SciTech Connect

In the investigation of the pumping behaviour of multiphase screw pumps, handling gas-liquid mixtures with very high gas volume fractions, theoretical and experimental analyses were performed. A new theoretical screw pump model was developed, which calculates the time-dependent conditions inside the several chambers of a screw pump as well as the exchange of mass and energy between these chambers. By means of the performed experimental analysis, the screw pump model was verified, especially at very high gas volume fractions from 90% to 99%. The experiments, which were conducted with the reference fluids water and air, can be divided mainly into the determination of the steady state pumping behaviour on the one hand and into the analysis of selected transient operating conditions on the other hand, whereas the visualisation of the leakage flows through the circumferential gaps was rounded off the experimental analysis. (author)

Raebiger, K. [LEISTRITZ Pumpen GmbH, Nuremberg (Germany); Faculty of Advanced Technology, University of Glamorgan, Pontypridd, Wales (United Kingdom); Maksoud, T.M.A.; Ward, J. [Faculty of Advanced Technology, University of Glamorgan, Pontypridd, Wales (United Kingdom); Hausmann, G. [Department of Mechanical Engineering and Building Services Engineering, University of Applied Sciences, Nuremberg (Germany)

2008-09-15T23:59:59.000Z

213

Proceedings: Fossil Plant Layup and Reactivation Conference  

Science Conference Proceedings (OSTI)

In recent years, the layup and reactivation of fossil-fired power plants has become more important as increasing numbers of utilities develop a need for retaining capacity not currently needed. A 1992 EPRI conference highlighted key technical issues, focusing on proven layup procedures, descriptions of layup equipment and preservation methods, layup and reactivation case studies, and summaries of regulatory issues.

1992-10-01T23:59:59.000Z

214

Simulations of highly reactive fluids  

SciTech Connect

We report density functional molecular dynamics simulations to determine the early chemical events of hot (T = 3000 K) and dense (1.97 g/cm{sup 3}, V/V{sub 0} = 0.68) nitromethane (CH{sub 3}NO{sub 2}). The first step in the decomposition process is an intermolecular proton abstraction mechanism that leads to the formation of CH{sub 3}NO{sub 2}H and the aci ion H{sub 2}CNO{sub 2}{sup -}, in support of evidence from static high-pressure and shock experiments. An intramolecular hydrogen transfer that transforms nitromethane into the aci acid form, CH{sub 2}NO{sub 2}H, accompanies this event. This is the first confirmation of chemical reactivity with bond selectivity for an energetic material near the condition of fully reacted specimen. We also report the decomposition mechanism followed up to the formation of H{sub 2}O as the first stable product.

Fried, L E; Manaa, M R; Reed, E J

2005-07-21T23:59:59.000Z

215

Reactive Power Measurement Using the Wavelet Transform  

E-Print Network (OSTI)

Abstract—This paper provides the theoretical basis for the measurement of reactive and distortion powers from the wavelet transforms. The measurement of reactive power relies on the use of broad-band phase-shift networks to create concurrent in-phase currents and quadrature voltages. The wavelet real power computation resulting from these 90 phase-shift networks yields the reactive power associated with each wavelet frequency level or subband. The distortion power at each wavelet subband is then derived from the real, reactive and apparent powers of the subband, where the apparent power is the product of the v; i element pair's subband rms voltage and current. The advantage of viewing the real and reactive powers in the wavelet domain is that the domain preserves both the frequency and time relationship of these powers. In addition, the reactive power associated with each wavelet subband is a signed quantity and thus has a direction associated with it. This permits tracking the reactive power flow in each subband through the power system. Index Terms—Digital signal processing, phase shift networks, measurement, power, RMS, subband, wavelets. I.

Weon-ki Yoon; Michael J. Devaney

2000-01-01T23:59:59.000Z

216

Comparison of biomass and coal char reactivities  

SciTech Connect

Char combustion is typically the rate limiting step during the combustion of solid fuels. The magnitude and variation of char reactivity during combustion are, therefore, of primary concern when comparing solid fuels such as coal and biomass. In an effort to evaluate biomass` potential as a sustainable and renewable energy source, the reactivities of both biomass and coal chars were compared using Sandia`s Captive Particle Imaging (CPI) apparatus. This paper summarizes the experimental approach used to determine biomass and coal reactivities and presents results from CPT experiments. The reactivity of six types of char particles, two high-rank coal chars, two low-rank coal chars, and two biomass chars, were investigated using the CPT apparatus. Results indicate that both of the high-rank coal chars have relatively low reactivities when compared with the higher reactivities measured for the low-rank coal and the biomass chars. In addition, extinction behavior of the chars support related investigations that suggest carbonaceous structural ordering is an important consideration in understanding particle reactivity as a function of extent of burnout. High-rank coal chars were found to have highly ordered carbon structures, where as, both low-rank coal and biomass chars were found to have highly disordered carbon structures.

Huey, S.P. [Sandia National Labs., Livermore, CA (United States); Davis, K.A. [Reaction Engineering International, Salt Lake City, UT (United States); Hurt, R.H. [Brown Univ., Providence, RI (United States). Div. of Engineering

1995-08-01T23:59:59.000Z

217

Systematic approach for chemical reactivity evaluation  

E-Print Network (OSTI)

Under certain conditions, reactive chemicals may proceed into uncontrolled chemical reaction pathways with rapid and significant increases in temperature, pressure, and/or gas evolution. Reactive chemicals have been involved in many industrial incidents, and have harmed people, property, and the environment. Evaluation of reactive chemical hazards is critical to design and operate safer chemical plant processes. Much effort is needed for experimental techniques, mainly calorimetric analysis, to measure thermal reactivity of chemical systems. Studying all the various reaction pathways experimentally however is very expensive and time consuming. Therefore, it is essential to employ simplified screening tools and other methods to reduce the number of experiments and to identify the most energetic pathways. A systematic approach is presented for the evaluation of reactive chemical hazards. This approach is based on a combination of computational methods, correlations, and experimental thermal analysis techniques. The presented approach will help to focus the experimental work to the most hazardous reaction scenarios with a better understanding of the reactive system chemistry. Computational methods are used to predict reaction stoichiometries, thermodynamics, and kinetics, which then are used to exclude thermodynamically infeasible and non-hazardous reaction pathways. Computational methods included: (1) molecular group contribution methods, (2) computational quantum chemistry methods, and (3) correlations based on thermodynamic-energy relationships. The experimental techniques are used to evaluate the most energetic systems for more accurate thermodynamic and kinetics parameters, or to replace inadequate numerical methods. The Reactive System Screening Tool (RSST) and the Automatic Pressure Tracking Adiabatic Calorimeter (APTAC) were employed to evaluate the reactive systems experimentally. The RSST detected exothermic behavior and measured the overall liberated energy. The APTAC simulated near-adiabatic runaway scenarios for more accurate thermodynamic and kinetic parameters. The validity of this approach was investigated through the evaluation of potentially hazardous reactive systems, including decomposition of di-tert-butyl peroxide, copolymerization of styrene-acrylonitrile, and polymerization of 1,3-butadiene.

Aldeeb, Abdulrehman Ahmed

2003-12-01T23:59:59.000Z

218

Theoretical and Experimental Evaluation of Chemical Reactivity  

E-Print Network (OSTI)

Reactive chemicals are presented widely in the chemical and petrochemical process industry. Their chemical reactivity hazards have posed a significant challenge to the industries of manufacturing, storage and transportation. The accidents due to reactive chemicals have caused tremendous loss of properties and lives, and damages to the environment. In this research, three classes of reactive chemicals (unsaturated hydrocarbons, self-reacting chemicals, energetic materials) were evaluated through theoretical and experimental methods. Methylcyclopentadiene (MCP) and Hydroxylamine (HA) are selected as representatives of unsaturated hydrocarbons and self-reacting chemicals, respectively. Chemical reactivity of MCP, including isomerization, dimerization, and oxidation, is investigated by computational chemistry methods and empirical thermodynamic–energy correlation. Density functional and ab initio methods are used to search the initial thermal decomposition steps of HA, including unimolecular and bimolecular pathways. In addition, solvent effects are also examined using water cluster methods and Polarizable Continuum Models (PCM) for aqueous solution of HA. The thermal stability of a basic energetic material, Nitroethane, is investigated through both theoretical and experimental methods. Density functional methods are employed to explore the initial decomposition pathways, followed by developing detailed reaction networks. Experiments with a batch reactor and in situ GC are designed to analyze the distribution of reaction products and verify reaction mechanisms. Overall kinetic model is also built from calorimetric experiments using an Automated Pressure Tracking Adiabatic Calorimeter (APTAC). Finally, a general evaluation approach is developed for a wide range of reactive chemicals. An index of thermal risk is proposed as a preliminary risk assessment to screen reactive chemicals. Correlations are also developed between reactivity parameters, such as onset temperature, activation energy, and adiabatic time to maximum rate based on a limited number, 37 sets, of Differential Scanning Calorimeter (DSC) data. The research shows broad applications in developing reaction mechanisms at the molecular level. The methodology of reaction modeling in combination with molecular modeling can also be used to study other reactive chemical systems.

Wang, Qingsheng

2010-08-01T23:59:59.000Z

219

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

E-Print Network (OSTI)

source term. The effective heat capacity is described by ( ?C g denote the speci?c heat capacity of the solid phase, theLiquid density Speci?c heat capacity of liquid phase Speci?c

Wang, W.

2010-01-01T23:59:59.000Z

220

COAL SLAGGING AND REACTIVITY TESTING  

SciTech Connect

Union Fenosa's La Robla I Power Station is a 270-MW Foster Wheeler arch-fired system. The unit is located at the mine that provides a portion of the semianthracitic coal. The remaining coals used are from South Africa, Russia, Australia, and China. The challenges at the La Robla I Station stem from the various fuels used, the characteristics of which differ from the design coal. The University of North Dakota Energy & Environmental Research Center (EERC) and the Lehigh University Energy Research Center (LUERC) undertook a program to assess problematic slagging and unburned carbon issues occurring at the plant. Full-scale combustion tests were performed under baseline conditions, with elevated oxygen level and with redistribution of air during a site visit at the plant. During these tests, operating information, observations and temperature measurements, and coal, slag deposit, and fly ash samples were obtained to assess slagging and unburned carbon. The slagging in almost all cases appeared due to elevated temperatures rather than fuel chemistry. The most severe slagging occurred when the temperature at the sampling port was in excess of 1500 C, with problematic slagging where first-observed temperatures exceeded 1350 C. The presence of anorthite crystals in the bulk of the deposits analyzed indicates that the temperatures were in excess of 1350 C, consistent with temperature measurements during the sampling period. Elevated temperatures and ''hot spots'' are probably the result of poor mill performance, and a poor distribution of the coal from the mills to the specific burners causes elevated temperatures in the regions where the slag samples were extracted. A contributing cause appeared to be poor combustion air mixing and heating, resulting in oxygen stratification and increased temperatures in certain areas. Air preheater plugging was observed and reduces the temperature of the air in the windbox, which leads to poor combustion conditions, resulting in unburned carbon as well as slagging. A second phase of the project involved advanced analysis of the baseline coal along with an Australian coal fired at the plant. These analysis results were used in equilibrium thermodynamic modeling along with a coal quality model developed by the EERC to assess slagging, fouling, and opacity for the coals. Bench-scale carbon conversion testing was performed in a drop-tube furnace to assess the reactivity of the coals. The Australian coal had a higher mineral content with significantly more clay minerals present than the baseline coal. The presence of these clay minerals, which tend to melt at relatively low temperatures, indicated a higher potential for problematic slagging than the baseline coal. However, the pyritic minerals, comprising over 25% of the baseline mineral content, may form sticky iron sulfides, leading to severe slagging in the burner region if local areas with reducing conditions exist. Modeling results indicated that neither would present significant fouling problems. The Australian coal was expected to show slagging behavior much more severe than the baseline coal except at very high furnace temperatures. However, the baseline coal was predicted to exhibit opacity problems, as well as have a higher potential for problematic calcium sulfate-based low-temperature fouling. The baseline coal had a somewhat higher reactivity than the Australian coal, which was consistent with both the lower average activation energy for the baseline coal and the greater carbon conversion at a given temperature and residence time. The activation energy of the baseline coal showed some effect of oxygen on the activation energy, with E{sub a} increasing at the lower oxygen concentration, but may be due to the scatter in the baseline coal kinetic values at the higher oxygen level tested.

Donald P. McCollor; Kurt E. Eylands; Jason D. Laumb

2003-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Final Report Phase II: Performance Evaluation of Permeable Reactive  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Final Report Phase II: Performance Evaluation of Permeable Reactive Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing More Documents & Publications Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Rejuvenating Permeable Reactive Barriers by Chemical Flushing Final Report - Rejuvenating Permeable Reactive Barriers by Chemical

222

Hydraulic Conductivity of the Monticello Permeable Reactive Barrier  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Hydraulic Conductivity of the Monticello Permeable Reactive Barrier Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update More Documents & Publications Variation in Hydraulic Conductivity Over Time at the Monticello Permeable Reactive Barrier Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium Mill Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium

223

Efficient and Reliable Reactive Power Supply and Consumption...  

NLE Websites -- All DOE Office Websites (Extended Search)

Efficient and Reliable Reactive Power Supply and Consumption - Insights from an Integrated Program of Engineering and Economics Research Title Efficient and Reliable Reactive Power...

224

Olefin production via reactive distillation based Olefin metathesis.  

E-Print Network (OSTI)

??Reactive distillation is a combination of a traditional multi-stage distillation column with a chemical reaction. The primary benefits of a reactive distillation process are reduced… (more)

Morrison, Ryan Frederick

2012-01-01T23:59:59.000Z

225

A Parametric Reactive Distillation Study: Economic Feasibility and Design Heuristics.  

E-Print Network (OSTI)

??The integration of reaction and distillation into a single column is called reactive distillation or catalytic distillation. Reactive distillation provides many benefits such as reduced… (more)

Hoyme, Craig Alan

2004-01-01T23:59:59.000Z

226

Observations on the Coke Air Reactivity Test - Programmaster.org  

Science Conference Proceedings (OSTI)

Coke air reactivities are strongly dependent on coke calcination levels and it is possible to drive air reactivities lower by increasing calcining temperatures.

227

Reactivity control assembly for nuclear reactor  

DOE Patents (OSTI)

Reactivity control assembly for nuclear reactor comprises supports stacked above reactor core for holding control rods. Couplers associated with the supports and a vertically movable drive shaft have lugs at their lower ends for engagement with the supports.

Bollinger, Lawrence R. (Schenectady, NY)

1984-01-01T23:59:59.000Z

228

A Tariff for Reactive Power - IEEE  

DOE Green Energy (OSTI)

This paper describes a suggested tariff or payment for the local supply of reactive power from distributed energy resources. The authors consider four sample customers, and estimate the cost of supply of reactive power for each customer. The power system savings from the local supply of reactive power are also estimated for a hypothetical circuit. It is found that reactive power for local voltage regulation could be supplied to the distribution system economically by customers when new inverters are installed. The inverter would be supplied with a power factor of 0.8, and would be capable of local voltage regulation to a schedule supplied by the utility. Inverters are now installed with photovoltaic systems, fuel cells and microturbines, and adjustable-speed motor drives.

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

2008-11-01T23:59:59.000Z

229

Mild coal pretreatment to improve liquefaction reactivity  

SciTech Connect

This report describes work completed during the fourth quarter of a three year project to study the effects of mild chemical pretreatment on coal dissolution reactivity during low severity liquefaction or coal/oil coprocessing. The overall objective of this research is to elucidate changes in the chemical and physical structure of coal by pretreating with methanol or other simple organic solvent and a trace amount of hydrochloric acid and measure the influence of these changes on coal dissolution reactivity. This work is part of a larger effort to develop a new coal liquefaction or coal/oil coprocessing scheme consisting of three main process steps: (1) mile pretreatment of the feed coal to enhance dissolution reactivity and dry the coal, (2) low severity thermal dissolution of the pretreated coal to obtain a very reactive coal-derived residual material amenable to upgrading, and (3) catalytic upgrading of the residual products to distillate liquids.

Miller, R.L.

1991-01-01T23:59:59.000Z

230

Groundwater well with reactive filter pack  

DOE Patents (OSTI)

A method and apparatus for the remediation of contaminated soil and ground water wherein a reactive pack material is added to the annular fill material utilized in standard well construction techniques.

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

1998-01-01T23:59:59.000Z

231

Fossil plant layup and reactivation conference: Proceedings  

Science Conference Proceedings (OSTI)

The Fossil Plant Layup and Reactivation Conference was held in New Orleans, Louisiana on April 14--15, 1992. The Conference was sponsored by EPRI and hosted by Entergy Services, Inc. to bring together representatives from utilities, consulting firms, manufacturers and architectural engineers. Eighteen papers were presented in three sessions. These sessions were devoted to layup procedures and practices, and reactivation case studies. A panel discussion was held on the second day to interactively discuss layup and reactivation issues. More than 80 people attended the Conference. This report contains technical papers and a summary of the panel discussion. Of the eighteen papers, three are related to general, one is related to regulatory issues, three are related to specific equipment, four are related to layup procedures and practices, and seven are layup and reactivation case studies.

Not Available

1992-10-01T23:59:59.000Z

232

Oxidation Resistance of Reactive Atoms in Graphene  

SciTech Connect

We have found that reactive elements that are normally oxidized at room temperature are present as individual atoms or clusters on and in graphene. Oxygen is present in these samples but it is only detected in the thicker amorphous carbon layers present in the graphene specimens we have examined. However, we have seen no evidence that oxygen reacts with the impurity atoms and small clusters of these normally reactive elements when they are incorporated in the graphene layers. First principles calculations suggest that the oxidation resistance is due to kinetic effects such as preferential bonding of oxygen to nonincorporated atoms and H passivation. The observed oxidation resistance of reactive atoms in graphene may allow the use of these incorporated metals in catalytic applications. It also opens the possibility of designing and producing electronic, opto-electronic, and magnetic devices based on these normally reactive atoms.

Chisholm, Matthew F [ORNL; Duscher, Gerd [University of Tennessee, Knoxville (UTK); Windl, Wolfgang [Ohio State University

2012-01-01T23:59:59.000Z

233

Radiative Forcing Due to Reactive Gas Emissions  

Science Conference Proceedings (OSTI)

Reactive gas emissions (CO, NOx, VOC) have indirect radiative forcing effects through their influences on tropospheric ozone and on the lifetimes of methane and hydrogenated halocarbons. These effects are quantified here for the full set of ...

T. M. L. Wigley; S. J. Smith; M. J. Prather

2002-09-01T23:59:59.000Z

234

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

Science Conference Proceedings (OSTI)

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.

Yannis C. Yortsos

2003-02-01T23:59:59.000Z

235

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

SciTech Connect

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.

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

2012-07-27T23:59:59.000Z

236

Enhanced Oxidative Reactivity for Anthracite Coal via a Reactive Ball Milling Pretreatment Step  

Science Conference Proceedings (OSTI)

Reactive ball milling in a cyclohexene solvent significantly increases the oxidative reactivity of an anthracite coal, due to the combined effects of particle size reduction, metal introduction, introduction of volatile matter, and changes in carbon structure. Metals introduced during milling can be easily removed via a subsequent demineralization process, and the increased reactivity is retained. Solvent addition alters the morphological changes that occur during pyrolysis and leads to a char with significantly increased reactivity. When the solvent is omitted, similar effects are seen for the milled product, but a significant fraction of the char is resistant to oxidation. 33 refs., 3 figs., 1 tab.

Angela D. Lueking; Apurba Sakti; Dania Alvarez-Fonseca; Nichole Wonderling [Pennsylvania State University, PA (United States). Department of Energy and Mineral Engineering

2009-09-15T23:59:59.000Z

237

review of extraction, processing, properties & applications of reactive ...  

Science Conference Proceedings (OSTI)

REVIEW OF EXTRACTION,. PROCESSING, PROPERTIES. & APPLICATIONS OF. REACTIVE METALS. Edited by. Brajendra Mishra ...

238

Final Report Phase II: Performance Evaluation of Permeable Reactive  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Final Report Phase II: Performance Evaluation of Permeable Reactive Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing More Documents & Publications Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report - Rejuvenating Permeable Reactive Barriers by Chemical Flushing, U.S. Environmental Protection Agency Region 8 Support

239

Phase II: Performance Evaluation of Permeable Reactive Barriers and  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Phase II: Performance Evaluation of Permeable Reactive Barriers and Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing U. S. Environmental Protection Agency Region 8 Support January 2004 Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing More Documents & Publications Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Rejuvenating Permeable Reactive Barriers by Chemical Flushing

240

Hydraulic Conductivity of the Monticello Permeable Reactive Barrier  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Hydraulic Conductivity of the Monticello Permeable Reactive Barrier Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update More Documents & Publications Variation in Hydraulic Conductivity Over Time at the Monticello Permeable Reactive Barrier Ground-Water Table and Chemical Changes in an Alluvial Aquifer During Sustained Pumping at the Monticello, Utah, Zero-Valent Iron Treatment Cells Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Transport Modeling of Reactive and Non-Reactive Constituents from Summitville,  

E-Print Network (OSTI)

Survey (USGS) began water- quality investigations at Summitville, Terrace #12;Figure 2. Aerial photographTransport Modeling of Reactive and Non- Reactive Constituents from Summitville, Colorado in the Wightman Fork/Alamosa River system downstream of the Summitville Mine, south-central Colorado, were

242

Nuclear engine flow reactivity shim control  

DOE Patents (OSTI)

A nuclear engine control system is provided which automatically compensates for reactor reactivity uncertainties at the start of life and reactivity losses due to core corrosion during the reactor life in gas-cooled reactors. The coolant gas flow is varied automatically by means of specially provided control apparatus so that the reactor control drums maintain a predetermined steady state position throughout the reactor life. This permits the reactor to be designed for a constant drum position and results in a desirable, relatively flat temperature profile across the core. (Official Gazette)

Walsh, J.M.

1973-12-11T23:59:59.000Z

243

Neutron Radiography Reactor Reactivity -- Focused Lessons Learned  

SciTech Connect

As part of the Global Threat Reduction Initiative, the Neutron Radiography Reactor (NRAD) at the Idaho National Laboratory (INL) was converted from using highly enriched uranium (HEU) to low enriched uranium (LEU) fuel. After the conversion, NRAD resumed operations and is meeting operational requirements. Radiography image quality and the number of images that can be produced in a given time frame match pre-conversion capabilities. However, following the conversion, NRAD’s excess reactivity with the LEU fuel was less than it had been with the HEU fuel. Although some differences between model predictions and actual performance are to be expected, the lack of flexibility in NRAD’s safety documentation prevented adjusting the reactivity by adding more fuel, until the safety documentation could be modified. To aid future reactor conversions, a reactivity-focused Lessons Learned meeting was held. This report summarizes the findings of the lessons learned meeting and addresses specific questions posed by DOE regarding NRAD’s conversion and reactivity.

Eric Woolstenhulme; Randal Damiana; Kenneth Schreck; Ann Marie Phillips; Dana Hewit

2010-11-01T23:59:59.000Z

244

LES algorithm for turbulent reactive flows simulation  

Science Conference Proceedings (OSTI)

The paper presents the development and implementation of a Large Eddy Simulation numerical algorithm for simulating turbulent reactive flows. The numerical algorithm is based on a 5 step modified Runge - Kutta numerical scheme with a dual time stepping ... Keywords: Runge - Kutta numerical scheme, large eddy simulation, linear eddy model

Ionut Porumbel; Cristian Cârl?nescu; Florin Gabriel Florean; Constantin Eusebiu Hritcu

2010-10-01T23:59:59.000Z

245

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

E-Print Network (OSTI)

Hydraulic fracturing has recently been the completion of choice for most tight gas bearing formations. It has proven successful to produce these formations in a commercial manner. However, some considerations have to be taken into account to design 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. Failing to account for that results in overestimating the deliverability of the well and, consequently, to designing a fracture treatment that is not optimum. In this work a thorough investigation of non-Darcy flow and multi-phase flow effects on the productivity of hydraulically fractured wells is conducted and an optimum fracture design is proposed for a tight gas formation in south Texas using the Unified Fracture Design (UFD) Technique to compensate for the mentioned effects by calculating the effective fracture permeability in an iterative way. Incorporating non-Darcy effects results in an optimum fracture that is shorter and wider than the fracture when only Darcy calculations are considered. That leads to a loss of production of 5, 18 percent due to dry and multiphase non-Darcy flow effects respectively. A comparison between the UFD and 3D simulators is also done to point out the differences in terms of methodology and results. Since UFD incorporated the maximum dimensionless productivity index in the fracture dimensions design, unlike 3D simulators, it can be concluded that using UFD to design the fracture treatment and then use the most important fracture parameters outputs (half length and CfDopt) as inputs in the simulators is a recommended approach.

Alarbi, Nasraldin Abdulslam A.

2011-08-01T23:59:59.000Z

246

Method for generating a highly reactive plasma for exhaust gas after treatment and enhanced catalyst reactivity  

DOE Patents (OSTI)

This patent application describes a method and apparatus of exhaust gas remediation that enhance the reactivity of the material catalysts found within catalytic converters of cars, trucks, and power stations.

Whealton, John H.; Hanson, Gregory R.; Storey, John M.; Raridon, Richard J.; Armfield, Jeffrey S.; Bigelow, Timothy S.; Graves, Ronald L.

2000-07-01T23:59:59.000Z

247

iTOUGH2 Command Reference  

Science Conference Proceedings (OSTI)

iTOUGH2 is a program for parameter estimation, sensitivity analysis, and uncertainty propagation analysis. It is based on the TOUGH2 simulator for non-isothermal multiphase flow in fractured and porous media. This report contains a detailed description of all iTOUGH2 commands.

Finsterle, Stefan

2002-06-18T23:59:59.000Z

248

ENVIRONMENTAL REACTIVITY OF SOLID STATE HYDRIDE MATERIALS  

DOE Green Energy (OSTI)

In searching for high gravimetric and volumetric density hydrogen storage systems, it is inevitable that higher energy density materials will be used. In order to make safe and commercially acceptable condensed phase hydrogen storage systems, it is important to understand quantitatively the risks involved in using and handling these materials and to develop appropriate mitigation strategies to handle potential material exposure events. A crucial aspect of the development of risk identification and mitigation strategies is the development of rigorous environmental reactivity testing standards and procedures. This will allow for the identification of potential risks and implementation of risk mitigation strategies. Modified testing procedures for shipping air and/or water sensitive materials, as codified by the United Nations, have been used to evaluate two potential hydrogen storage materials, 2LiBH{sub 4} {center_dot} MgH{sub 2} and NH{sub 3}BH{sub 3}. The modified U.N. procedures include identification of self-reactive substances, pyrophoric substances, and gas-emitting substances with water contact. The results of these tests for air and water contact sensitivity will be compared to the pure material components where appropriate (e.g. LiBH{sub 4} and MgH{sub 2}). The water contact tests are divided into two scenarios dependent on the hydride to water mole ratio and heat transport characteristics. Air contact tests were run to determine whether a substance will spontaneously react with air in a packed or dispersed form. In the case of the 2LiBH{sub 4} {center_dot} MgH{sub 2} material, the results from the hydride mixture compared to the pure materials results showed the MgH{sub 2} to be the least reactive component and LiBH{sub 4} the more reactive. The combined 2LiBH{sub 4} {center_dot} MgH{sub 2} resulted in a material having environmental reactivity between these two materials. Relative to 2LiBH{sub 4} {center_dot} MgH{sub 2}, the chemical hydride NH{sub 3}BH{sub 3} was observed to be less environmentally reactive.

Gray, J; Donald Anton, D

2009-04-23T23:59:59.000Z

249

Behavior of Laminate Reactive Materials under Dynamic Loading ...  

Science Conference Proceedings (OSTI)

Presentation Title, Behavior of Laminate Reactive Materials under Dynamic Loading ... Atomistically-Informed Dislocation Dynamics Simulations of High Rate  ...

250

SIC Manufature via Reactive Infiltration - Programmaster.org  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Ceramic Matrix Composites. Presentation Title, SIC Manufature via Reactive ...

251

Multiple Steady States in Azeotropic and Reactive Distillation  

E-Print Network (OSTI)

Introduction . Motivation Overview on the Contributions MSS in Reactive Distillation Conclusions Outline Multiple Steady States (MSS) Overview on the Contributions . The Starting Point . Consolidation . Industrial Applications . Incorporating Reactions MSS in Reactive Distillation Conclusions Outline Multiple Steady States (MSS) Overview on the Contributions MSS in Reactive Distillation . Prediction Method . MTBE Process Conclusions Outline Multiple Steady States (MSS) Overview on the Contributions MSS in Reactive Distillation Conclusions Distillation Overview . Ideal binary / multicomponent distillation . Homogeneous azeotropic distillation -- Heavy entrainer (extractive distillation) -- Intermediate entrainer -- "Boundary scheme" (ligh

Thomas E. Güttinger

1998-01-01T23:59:59.000Z

252

Image analysis algorithms for estimating porous media multiphase flow variables from computed microtomography data: a validation study  

Science Conference Proceedings (OSTI)

Image analysis of three-dimensional microtomographic image data has become an integral component of pore scale investigations of multiphase flow through porous media. This study focuses on the validation of image analysis algorithms for identifying phases and estimating porosity, saturation, solid surface area, and interfacial area between fluid phases from gray-scale X-ray microtomographic image data. The data used in this study consisted of (1) a two-phase high precision bead pack from which porosity and solid surface area estimates were obtained and (2) three-phase cylindrical capillary tubes of three different radii, each containing an air-water interface, from which interfacial area was estimated. The image analysis algorithm employed here combines an anisotropic diffusion filter to remove noise from the original gray-scale image data, a k-means cluster analysis to obtain segmented data, and the construction of isosurfaces to estimate solid surface area and interfacial area. Our method was compared with laboratory measurements, as well as estimates obtained from a number of other image analysis algorithms presented in the literature. Porosity estimates for the two-phase bead pack were within 1.5% error of laboratory measurements and agreed well with estimates obtained using an indicator kriging segmentation algorithm. Additionally, our method estimated the solid surface area of the high precision beads within 10% of the laboratory measurements, whereas solid surface area estimates obtained from voxel counting and two-point correlation functions overestimated the surface area by 20--40%. Interfacial area estimates for the air-water menisci contained within the capillary tubes were obtained using our image analysis algorithm, and using other image analysis algorithms, including voxel counting, two-point correlation functions, and the porous media marching cubes. Our image analysis algorithm, and other algorithms based on marching cubes, resulted in errors ranging from 1% to 20% of the analytical interfacial area estimates, whereas voxel counting and two-point correlation functions overestimated the analytical interfacial area by 20--40%. In addition, the sensitivity of the image analysis algorithms on the resolution of the microtomographic image data was investigated, and the results indicated that there was little or no improvement in the comparison with laboratory estimates for the resolutions and conditions tested.

Porter, Mark L.; Wildenschild, Dorthe; (Oregon State U.)

2010-09-03T23:59:59.000Z

253

Development of Micro/Nano-Scale Sensors for Investigation of Heat Transfer in Multi-Phase Flows  

E-Print Network (OSTI)

The objective of this investigation was to develop micro/nano-scale temperature sensors for measuring surface temperature transients in multi-phase flows and heat transfer. Surface temperature fluctuations were measured on substrates exposed to phase change processes. Prior reports in the literature indicate that these miniature scale surface temperature fluctuations can result in 60-90 percent of the total heat flux during phase change heat transfer. In this study, DTS (Diode Temperature Sensors) were fabricated with a doping depth of ~100 nm on n-type silicon to measure the surface temperature transients on a substrate exposed to droplet impingement cooling. DTS are expected to have better sensor characteristics compared to TFTs (Thin Film Thermocouples), due to their small size and faster response (which comes at the expense of the smaller operating temperature range). Additional advantages of DTS include the availability of robust commercial micro fabrication processes (with diode and transistor node sizes currently in the size range of ~ 30 nm), and that only 2N wire leads can be used to interrogate a set of N x N array of sensors (in contrast thermocouples require 2 N x N wire leads for N x N sensor array). The DTS array was fabricated using conventional semi-conductor processes. The temperature response of the TFT and DTS was also calibrated using NIST standards. Transient temperature response of the DTS was recorded using droplet impingement cooling experiments. The droplet impingement cooling experiments were performed for two different test fluids (acetone and ethanol). An infrared camera was used to verify the surface temperature of the substrate and compare these measurements with the temperature values recorded by individual DTS. PVD (Physical Vapor Deposition) was used for obtaining the catalyst coatings for subsequent CNT synthesis using CVD (Chemical Vapor Deposition) as well as for fabricating the thin film thermocouple (TFT) arrays using the "lift-off" process. Flow boiling experiments were conducted for three different substrates. Flow boiling experiments on bare silicon wafer surface were treated as the control experiment, and the results were compared with that of CNT (Carbon Nano-Tube) coated silicon wafer surfaces. Similar experiments were also performed on a pure copper surface. In addition, experiments were performed using compact condensers. Micro-scale patterns fabricated on the refrigerant side of the compact heat exchanger were observed to cause significant enhancement of the condensation heat transfer coefficient.

Jeon, Sae Il

2011-08-01T23:59:59.000Z

254

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

DOE Green Energy (OSTI)

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.

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

2010-09-01T23:59:59.000Z

255

Nuclear reactivity control using laser induced polarization  

DOE Patents (OSTI)

A control element for reactivity control of a fission source provides an atomic density of .sup.3 He in a control volume which is effective to control criticality as the .sup.3 He is spin-polarized. Spin-polarization of the .sup.3 He affects the cross section of the control volume for fission neutrons and hence, the reactivity. An irradiation source is directed within the .sup.3 He for spin-polarizing the .sup.3 He. An alkali-metal vapor may be included with the .sup.3 He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with .sup.3 He to spin-polarize the .sup.3 He atoms.

Bowman, Charles D. (Los Alamos, NM)

1991-01-01T23:59:59.000Z

256

Nuclear reactivity control using laser induced polarization  

DOE Patents (OSTI)

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.

Bowman, Charles D. (Los Alamos, NM)

1990-01-01T23:59:59.000Z

257

Reactivity control assembly for nuclear reactor. [LMFBR  

DOE Patents (OSTI)

This invention, which resulted from a contact with the United States Department of Energy, relates to a control mechanism for a nuclear reactor and, more particularly, to an assembly for selectively shifting different numbers of reactivity modifying rods into and out of the core of a nuclear reactor. It has been proposed heretofore to control the reactivity of a breeder reactor by varying the depth of insertion of control rods (e.g., rods containing a fertile material such as ThO/sub 2/) in the core of the reactor, thereby varying the amount of neutron-thermalizing coolant and the amount of neutron-capturing material in the core. This invention relates to a mechanism which can advantageously be used in this type of reactor control system.

Bollinger, L.R.

1982-03-17T23:59:59.000Z

258

Treatment of Radioactive Reactive Mixed Waste  

Science Conference Proceedings (OSTI)

PacificEcoSolutions, Inc. (PEcoS) has installed a plasma gasification system that was recently modified and used to destroy a trimethyl-aluminum mixed waste stream from Los Alamos National Laboratory (LANL.) The unique challenge in handling reactive wastes like trimethyl-aluminum is their propensity to flame instantly on contact with air and to react violently with water. To safely address this issue, PacificEcoSolutions has developed a new feed system to ensure the safe containment of these radioactive reactive wastes during transfer to the gasification unit. The plasma gasification system safely processed the radioactively contaminated trimethyl-metal compounds into metal oxides. The waste stream came from LANL research operations, and had been in storage for seven years, pending treatment options. (authors)

Colby, S.; Turner, Z.; Utley, D. [Pacific EcoSolutions, Inc., 2025 Battelle Boulevard, Richland, Washington 99354 (United States); Duy, C. [Los Alamos National Laboratory - LA-UR-05-8410, Post Office Box 1663 MS J595, Los Alamos, New Mexico 97545 (United States)

2006-07-01T23:59:59.000Z

259

Nuclear reactivity control using laser induced polarization  

DOE Patents (OSTI)

A control element for reactivity control of a fission source provides an atomic density of {sup 3}He in a control volume which is effective to control criticality as the {sup 3}He is spin-polarized. Spin-polarization of the {sup 3}He affects the cross section of the control volume for fission neutrons and hence, the reactivity. An irradiation source is directed within the {sup 3}He for spin-polarizing the {sup 3}He. An alkali-metal vapor may be included with the {sup 3}He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with {sup 3}He to spin-polarize the {sup 3}He atoms. 5 figs.

Bowman, C.D.

1989-05-26T23:59:59.000Z

260

Real time reactive programming in lucid enriched with contexts  

Science Conference Proceedings (OSTI)

We present a synchronous approach to real-time reactive programming in Lucid enriched with contexts as first class objects. The declarative intensional approach allows real-time reactive programs to manipulate both events and state-based representations ... Keywords: contexts, formal verification, intensional programming, real-time reactive programming

Kaiyu Wan; Vasu Alagar; Joey Paquet

2004-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

From model conception to verification and validation, a global approach to multiphase Navier-Stoke models with an emphasis on volcanic explosive phenomenology  

Science Conference Proceedings (OSTI)

Large-scale volcanic eruptions are hazardous events that cannot be described by detailed and accurate in situ measurement: hence, little to no real-time data exists to rigorously validate current computer models of these events. In addition, such phenomenology involves highly complex, nonlinear, and unsteady physical behaviors upon many spatial and time scales. As a result, volcanic explosive phenomenology is poorly understood in terms of its physics, and inadequately constrained in terms of initial, boundary, and inflow conditions. Nevertheless, code verification and validation become even more critical because more and more volcanologists use numerical data for assessment and mitigation of volcanic hazards. In this report, we evaluate the process of model and code development in the context of geophysical multiphase flows. We describe: (1) the conception of a theoretical, multiphase, Navier-Stokes model, (2) its implementation into a numerical code, (3) the verification of the code, and (4) the validation of such a model within the context of turbulent and underexpanded jet physics. Within the validation framework, we suggest focusing on the key physics that control the volcanic clouds—namely, momentum-driven supersonic jet and buoyancy-driven turbulent plume. For instance, we propose to compare numerical results against a set of simple and well-constrained analog experiments, which uniquely and unambiguously represent each of the key-phenomenology. Key

Dartevelle, Sebastian

2007-10-01T23:59:59.000Z

262

Groundwater modeling: Application of a multiphase fluid flow model as a decision-making tool for assessing and remediating installation restoration program sites. Master's thesis  

Science Conference Proceedings (OSTI)

This research examined a two-dimensional numerical model, VALOR, which can simulate multiphase fluid flow in soils and groundwater, and evaluated the applicability of the model as a decision-making tool for assessing and remediating IRP sites. Model sensitivity analyses were conducted to study the influence of grid sizes, soil types, and organic release rates on the simulated migration of both light and dense non-aqueous phase liquids (NAPLs). The VALOR model was applied to a case study of a JP-4 release at Wright-Patterson AFB, Ohio. The finer grid sizes provide the most accurate definition of NAPL distribution. The soil type and release rate sensitivity analyses demonstrate that NAPL migrates quicker through coarse sands than fine sand and clay. The light NAPL ponds at the water table and spreads laterally. The dense NAPL migrates through the subsurface and ponds at the aquifer bottom. The fast organic release simulations predict wider vertical pathways of migration. The slow organic release simulations predict higher light NAPL saturation at the water table. The case study indicates that within limits, VALOR may be useful for assessing NAPL distribution, estimating contaminated soil volumes, and evaluating remediation alternatives.... Groundwater modeling, Non-aqueous Phase Liquids: NAPL, Multiphase fluid flow model, Installation Restoration Program, IRP.

Scott, D.J.

1993-09-01T23:59:59.000Z

263

FEHMN 1.0: Finite element heat and mass transfer code  

DOE Green Energy (OSTI)

A computer code is described which can simulate non-isothermal multiphase multicomponent flow in porous media. It is applicable to natural-state studies of geothermal systems and ground-water flow. The equations of heat and mass transfer for multiphase flow in porous and permeable media are solved using the finite element method. The permeability and porosity of the medium are allowed to depend on pressure and temperature. The code also has provisions for movable air and water phases and noncoupled tracers; that is, tracer solutions that do not affect the heat and mass transfer solutions. The tracers can be passive or reactive. The code can simulate two-dimensional, two-dimensional radial, or three-dimensional geometries. A summary of the equations in the model and the numerical solution procedure are provided in this report. A user`s guide and sample problems are also included. The main use of FEHMN will be to assist in the understanding of flow fields in the saturated zone below the proposed Yucca Mountain Repository. 33 refs., 27 figs., 12 tabs.

Zyvoloski, G.; Dash, Z.; Kelkar, S.

1991-04-01T23:59:59.000Z

264

FEHMN 1.0: Finite element heat and mass transfer code; Revision 1  

Science Conference Proceedings (OSTI)

A computer code is described which can simulate non-isothermal multi-phase multicomponent flow in porous media. It is applicable to natural-state studies of geothermal systems and groundwater flow. The equations of heat and mass transfer for multiphase flow in porous and permeable media are solved sing the finite element method. The permeability and porosity of the medium are allowed to depend on pressure and temperature. The code also has provisions for movable air and water phases and noncoupled tracers; that is, tracer solutions that do not affect the heat and mass transfer solutions. The tracers can be passive or reactive. The code can simulate two-dimensional, two-dimensional radial, or three-dimensional geometries. A summary of the equations in the model and the numerical solution procedure are provided in this report. A user`s guide and sample problems are also included. The FEHMN (Finite Element Heat and Mass Nuclear) code, described in this report, is a version of FEHM (Finite Element Heat and Mass, Zyvoloski et al., 1988) developed for the Yucca Mountain Site Characterization Project (YMP). The main use of FEHMN will be to assist in the understanding of flow fields in the saturated zone below the potential Yucca Mountain repository.

Zyvoloski, G.; Dash, Z.; Kelkar, S.

1992-05-01T23:59:59.000Z

265

Multiphase and Multicomponent Materials  

Science Conference Proceedings (OSTI)

The microstructure of the adhered material consisted of oxide ligaments ( nanowires, NWs) that served to attach the debris to tool steel surface as revealed by ...

266

Mulitcomponent Multiphase Diffusion  

Science Conference Proceedings (OSTI)

... 54 (2006) p 2431-2439. pdf file; "Hillert, Höglund, and Ågren, "Diffusion in interstitial compounds with thermal and stoichiometric defects," J. Appl. ...

2008-07-22T23:59:59.000Z

267

Preparation of reactive beta-dicalcium silicate  

DOE Patents (OSTI)

This invention relates to the preparation of fine particles of reactive beta-dicalcium silicate by means of a solid state process which comprises firing a mixture of calcium sulfate, silica and a reducing additive selected from the group consisting of calcium sulfide, carbon, carbon monoxide, methane and hydrogen, at a temperature of about 850.degree.-1000.degree. C. A carrier gas such as nitrogen or carbon dioxide may also be added, if desired. A high concentration of sulfur dioxide is a by-product of this process.

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

1982-01-01T23:59:59.000Z

268

Preparation of reactive beta-dicalcium silicate  

DOE Patents (OSTI)

This invention relates to the preparation of fine particles of reactive beta-dicalcium silicate by means of a solid state process which comprises firing a mixture of calcium sulfate, silica, and a reducing additive selected from the group consisting of calcium sulfide, carbon, carbon monoxide, methane, and hydrogen, at a temperature of about 850 to 1000/sup 0/C. A carrier gas such as nitrogen or carbon dioxide may also be added, if desired. A high concentration of sulfur dioxide is a by-product of this process.

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

1980-02-28T23:59:59.000Z

269

Reactive sticking coefficients of silane on silicon  

SciTech Connect

Reactive sticking coefficients (RSCs) were measured for silane and disilane on polycrystalline silicon for a wide range of temperature and flux (pressure) conditions. The data were obtained from deposition rate measurements using molecular beam scattering and a very low pressure cold wall reactor. The RSCs have non-Arrhenius temperature dependences and decreases with increasing flux at low (710/sup 0/) temperatures. A simple model involving dissociative adsorption of silane is consistent with these results. The results are compared with previous studies of the SiH/sub 4//Si(s) reaction.

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

1988-09-15T23:59:59.000Z

270

Mechanistic Reactive Burn Modeling of Solid Explosives  

SciTech Connect

This report describes a computational framework for reactive burn modeling of solid explosives and the development of a test case where physical mechanisms represent RDX or RDX-based materials. The report is a sequel to LA-13794-MS, ''A Unifying Framework for Hot Spots and the Ignition of Energetic Materials,'' where we proposed a new approach to the building of a general purpose model that captures the essential features of the three primary origins of hot-spot formation: void collapse, shear banding, friction. The purpose of the present report is to describe the continuing task of coupling the unifying hot-spot model to hydrodynamic calculations to develop a mechanistic reactive burn model. The key components of the coupling include energy localization, the growth of hot spots, overall hot-spot behavior, and a phase-averaged mixture equation of state (EOS) in a Mie-Grueneisen form. The nucleation and growth of locally heated regions is modeled by a phenomenological treatment as well as a statistical model based on an exponential size distribution. The Mie-Grueneisen form of the EOS is one of many possible choices and is not a critical selection for implementing the model. In this report, model calculations are limited to proof-of-concept illustrations for shock loading. Results include (1) shock ignition and growth-to-detonation, (2) double shock ignition, and (3) quenching and reignition. A comparative study of Pop-plots is discussed based on the statistical model.

Y.Horie; Y.Hamate; D.Greening

2003-04-01T23:59:59.000Z

271

Reactive thermal waves in energetic materials  

SciTech Connect

Reactive thermal waves (RTWs) arise in several energetic material applications, including self-propagating high-temperature synthesis (SHS), high explosive cookoff, and the detonation of heterogeneous explosives. In this paper I exmaine ideal RTWs, by which I mean that (1) material motion is neglected, (2) the state dependence of reaction is Arrhenius in the temperature, and (3) the reaction rate is modulated by an arbitrary mass-fraction-based reaction progress function. Numerical simulations demonstrate that one's natural intuition, which is based mainly upon experience with inert materials and which leads one to expect diffusion processes to become relatively slow after a short time period, is invalid for high energy, state-sensitive reactive systems. Instead, theory predicts that RTWs can propagate at very high speeds. This result agrees with estimates for detonating heterogeneous explosives, which indicate that RTWs must spread from hot-spot nucleation sites at rates comparable to the detonation speed in order to produce experimentally-observed reaction zone thicknesses. Using dimensionless scaling and further invoking the high activation energy approximation, I obtain an analytic formula for the steady plane RTW speed from numerical calculations. I then compute the RTW speed for real explosives, and discuss aspects of their behavior.

Hill, Larry G [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

272

Mild coal pretreatment to improve liquefaction reactivity  

SciTech Connect

This report describes work completed during the fifth quarter of a three year project to study the effects of mild chemical pretreatment on coal dissolution reactivity during low severity liquefaction or coal/oil coprocessing. The overall objective of this research is to elucidate changes in the chemical and physical structure of coal by pretreating with methanol or other simple organic solvent and a trace amount of hydrochloric acid and measure the influence of these changes on coal dissolution reactivity. Work this quarter focused on analytical characterization of untreated and treated Wyodak subbituminous coal and Illinois {number sign}6 bituminous coal. Mossbauer spectroscopy and x-ray diffraction techniques were used to study the effect of methanol/HCl pretreatment on the composition of each coal's inorganic phase. Results from these studies indicated that calcite is largely removed during pretreatment, but that other mineral species such as pyrite are unaffected. This finding is significant, since calcite removal appears to directly correlate with low severity liquefaction enhancement. Further work will be performed to study this phenomenon in more detail.

Miller, R.L.

1991-01-01T23:59:59.000Z

273

Actinide and xenon reactivity effects in ATW high flux systems  

SciTech Connect

In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides.

Woosley, M.; Olson, K.; Henderson, D. L.; Sailor, W. C. [Department of Mechanical, Aerospace, and Nuclear Engineering University of Virginia, Charlottesville, Virginia 22903 (United States); Department of Nuclear Engineering and Engineering Physics University of Wisconsin, Madison, Wisconsin 53706-1687 (United States); Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1995-09-15T23:59:59.000Z

274

Knudsen Layer Reduction of Fusion Reactivity Kim Molvig and Nelson...  

NLE Websites -- All DOE Office Websites (Extended Search)

fusion cross section determine Gamow peak in the fusion reactivity. 2 Inertially confined fusion systems typically have plasma fuel enveloped by a cold non-reacting region or...

275

SP-19: Electrochemistry of Enargite: Reactivity in Alkaline Solutions  

Science Conference Proceedings (OSTI)

The reactivity of enargite samples from Montana, US and Quiruvilca, Peru were studied under alkaline conditions, pH range of 8-13, using a cyclic voltammetry ...

276

Advancing Reactive Tracer Methods for Measuring Thermal Evolution...  

Open Energy Info (EERE)

History Facebook icon Twitter icon Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2- and Water-Based Geothermal Reservoirs Geothermal Lab Call Project...

277

Chombo-Crunch: Advanced Simulation of Subsurface Flow and Reactive...  

NLE Websites -- All DOE Office Websites (Extended Search)

Chombo-Crunch: Advanced Simulation of Subsurface Flow and Reactive Transport Processes Associated with Carbon Sequestration PI Name: David Trebotich Institution: Lawrence Berkeley...

278

Instrumentation @ Catalysis: Reactivity and Structure Group | Chemistry  

NLE Websites -- All DOE Office Websites (Extended Search)

Instrumentation Instrumentation The Catalysis Group at BNL is leading research initiatives into the development of new tools and techniques that focus on the characterization of heterogeneous catalytic reactions and catalysts using imaging, spectroscopy and scattering techniques and integrated combinations of them under reaction conditions to unravel the morphology, chemical and structural properties, of catalysts, respectively. These efforts revolve around the use of synchrotron radiation (NSLS), electrons (CFN) and quantum tunneling tools with particular thrusts into imaging, spectroscopy and scattering. Groups Instrumentation(BNL) Three UHV chambers with diverse instrumentation for surface characterization: LEED, UPS, XPS, AES, TPD, ISS, PM-AP-IRRAS, Reactivity Cell. All the systems include ancillary instrumentation such as sputtering guns and metal evaporators. The IRRAS system was retrofitted with an ambient pressure (AP) cell on top of the UHV system. The sample can be prepared and characterized in UHV and then transfer in vacuum to the AP cell.

279

Using laboratory flow experiments and reactive chemical transport modeling for designing waterflooding of the Agua Fria Reservoir, Poza Rica-Altamira Field, Mexico  

SciTech Connect

Waterflooding for enhanced oil recovery requires that injected waters must be chemically compatible with connate reservoir waters, in order to avoid mineral dissolution-and-precipitation cycles that could seriously degrade formation permeability and injectivity. Formation plugging is a concern especially in reservoirs with a large content of carbonates, such as calcite and dolomite, as such minerals typically react rapidly with an aqueous phase, and have strongly temperature-dependent solubility. Clay swelling can also pose problems. During a preliminary waterflooding pilot project, the Poza Rica-Altamira oil field, bordering the Gulf coast in the eastern part of Mexico, experienced injectivity loss after five months of reinjection of formation waters into well AF-847 in 1999. Acidizing with HCl restored injectivity. We report on laboratory experiments and reactive chemistry modeling studies that were undertaken in preparation for long-term waterflooding at Agua Frma. Using analogous core plugs obtained from the same reservoir interval, laboratory coreflood experiments were conducted to examine sensitivity of mineral dissolution and precipitation effects to water composition. Native reservoir water, chemically altered waters, and distilled water were used, and temporal changes in core permeability, mineral abundances and aqueous concentrations of solutes were monitored. The experiments were simulated with the multi-phase, nonisothermal reactive transport code TOUGHREACT, and reasonable to good agreement was obtained for changes in solute concentrations. Clay swelling caused an additional impact on permeability behavior during coreflood experiments, whereas the modeled permeability depends exclusively on chemical processes. TOUGHREACT was then used for reservoir-scale simulation of injecting ambient-temperature water (30 C, 86 F) into a reservoir with initial temperature of 80 C (176 F). Untreated native reservoir water was found to cause serious porosity and permeability reduction due to calcite precipitation, which is promoted by the retrograde solubility of this mineral. Using treated water that performed well in the laboratory flow experiments was found to avoid excessive precipitation, and allowed injection to proceed.

Birkle, P.; Pruess, K.; Xu, T.; Figueroa, R.A. Hernandez; Lopez, M. Diaz; Lopez, E. Contreras

2008-10-01T23:59:59.000Z

280

Artificial bee colony algorithm solution for optimal reactive power flow  

Science Conference Proceedings (OSTI)

Artificial bee colony (ABC) algorithm is an optimization algorithm based on the intelligent foraging behavior of honeybee swarm. Optimal reactive power flow (ORPF) based on ABC algorithm to minimize active power loss in power systems is studied in this ... Keywords: Artificial bee colony, Optimal reactive power flow, Penalty function, Power system

Kür?at Ayan; Ula? K?l?ç

2012-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

A formal approach for the development of reactive systems  

Science Conference Proceedings (OSTI)

Context: This paper deals with the development and verification of liveness properties on reactive systems using the Event-B method. By considering the limitation of the Event-B method to invariance properties, we propose to apply the language TLA^+ ... Keywords: Event-B method, Language TLA+, Liveness properties, Reactive systems, Refinement, Verification

Olfa Mosbahi; Leila Jemni Ben Ayed; Mohamed Khalgui

2011-01-01T23:59:59.000Z

282

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 as efficient and optimal production and prices for real and reactive power. The purpose of this paper delivery of electric power. To accomplish this end, the paper opens with specification of an economic

283

Differential evolution approach for optimal reactive power dispatch  

Science Conference Proceedings (OSTI)

Differential evolution based optimal reactive power dispatch for real power loss minimization in power system is presented in this paper. The proposed methodology determines control variable settings such as generator terminal voltages, tap positions ... Keywords: Differential evolution, Loss minimization, Optimal power flow, Penalty function, Reactive power dispatch

M. Varadarajan; K. S. Swarup

2008-09-01T23:59:59.000Z

284

Reactive Power Compensation Technologies, State-of-the-Art Review  

E-Print Network (OSTI)

reactors to provide or absorb the required reactive power have been developed [7], [8], [9]. Also, the use static VAR generators, using power electronic technologies have been proposed and developed [7 compensators (SVC) consist of standard reactive power shunt elements (reactors and capacitors) which

Rudnick, Hugh

285

Variational reactivity estimates: new analyses and new results  

SciTech Connect

A modified form of the variational estimate of the reactivity worth ofa perturbation was previously developed to extend the range of applicability of variational perturbation theory for perturbations leading to negative reactivity worths. Recent numerical results challenged the assumptions behind the modified form. In this paper, more results are obtained, leading to the conclusion that sometimes the modified form extends the range ofapplicability of variational perturbation theory for positive reactivity worths as well, and sometimes the standard variational form is more accurate for negative-reactivity perturbations. In addition, this paper proves that using the exact generalized adjoint function would lead to an inaccurate variational reactivity estimate when the error in the first-order estimate is large; the standard generalized adjoint function, an approximation to the exact one, leads to Lore accurate results. This conclusion is also demonstrated numerically. Transport calculations use the PARTISN multi group discrete ordinates code

Favorite, Jeffrey A [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

286

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)

Early maturation processes in coal. Part 2: Reactive dynamics simulations using the ReaxFF reactive force field on Morwell Brown coal structures Elodie Salmon a , Adri C.T. van Duin b , François Lorant Brown coal using the ReaxFF reactive force field. We find that these reactive MD simulations

Goddard III, William A.

287

Reactive sticking coefficients of silane on silicon  

SciTech Connect

We have investigated the reaction of room-temperature silane and disilane on a hot polycrystalline silicon surface using both a collision-free molecular beam and a very low pressure CVD cell. Reactive sticking coefficients were obtained from deposition rate data over a wide range of temperatures and silane (disilane) fluxes. The RSCs are substantially less than one, ranging from 6 x 10/sup -5/ to 4 x 10/sup -2/. For silane we observed curved Arrhenius plots with slopes decreasing from approx.60 kcal mol/sup -1/ at low temperatures to approx.2 kcal mol/sup -1/ at higher temperatures. The RSCs are independent of flux (pressure) at 1040/sup 0/C, but vary as flux to the approx.-1/2 power at 710/sup 0/C. A model comprised of a dissociative adsorption mechanism with competing associative desorption and reaction was found to give reasonable agreement. For disilane, we observed RSCs that were roughly ten times higher than those for silane. We also observed a curved Arrhenius plot and a flux dependence at 710/sup 0/C for disilane. 22 refs., 5 figs.

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

1987-01-01T23:59:59.000Z

288

Reactivity of coals under coprocessing conditions  

DOE Green Energy (OSTI)

In the recent years greater interest has developed for processes involving coal and petroleum fractions to produce distillate fuels. Coprocessing is especially attractive as a direct liquefaction process because it involves the use of heavy petroleum fractions, so both coal and heavy petroleum resids are upgraded simultaneously. The main distinction of coprocessing from other direct liquefaction processes is that coprocessing is more complex from a chemical standpoint than direct liquefaction processes which use traditional solvents, due to the greater variety of hydrocarbons (aromatic from the coal and aliphatics from the petroleum) present in the system. Therefore, need arises for better understanding of the chemical and physical interactions during coprocessing. The aim of the present study is to examine the influence of reaction conditions, coal and petroleum resid properties as well as the compatibility of the coal/petroleum resid pairs in terms of structural components on total coal conversion. Special focus will be given to the reactivity of coals and interaction of the coal and resid which lead to anisotropic coke.

Tomic, J.; Schobert, H.H.

1992-06-01T23:59:59.000Z

289

Reactivity of coals under coprocessing conditions  

DOE Green Energy (OSTI)

In the recent years greater interest has developed for processes involving coal and petroleum fractions to produce distillate fuels. Coprocessing is especially attractive as a direct liquefaction process because it involves the use of heavy petroleum fractions, so both coal and heavy petroleum resids are upgraded simultaneously. The main distinction of coprocessing from other direct liquefaction processes is that coprocessing is more complex from a chemical standpoint than direct liquefaction processes which use traditional solvents, due to the greater variety of hydrocarbons (aromatic from the coal and aliphatics from the petroleum) present in the system. Therefore, need arises for better understanding of the chemical and physical interactions during coprocessing. The aim of the present study is to examine the influence of reaction conditions, coal and petroleum resid properties as well as the compatibility of the coal/petroleum resid pairs in terms of structural components on total coal conversion. Special focus will be given to the reactivity of coals and interaction of the coal and resid which lead to anisotropic coke.

Tomic, J.; Schobert, H.H.

1992-01-01T23:59:59.000Z

290

Advanced Simulation Capability for Environmental Management  

Multi-Process High Performance Computing Simulator Modular simulation capability for barrier and waste form degradation, multiphase flow and reactive ...

291

Method for generating a highly reactive plasma for exhaust gas aftertreatment and enhanced catalyst reactivity  

DOE Patents (OSTI)

A method for non-thermal plasma aftertreatment of exhaust gases the method comprising the steps of providing short risetime, high frequency, high power bursts of low-duty factor microwaves sufficient to generate a plasma discharge and passing a gas to be treated through the discharge so as to cause dissociative reduction of the exhaust gases and enhanced catalyst reactivity through application of the pulsed microwave fields directly to the catalyst material sufficient to cause a polarizability catastrophe and enhanced heating of the metal crystallite particles of the catalyst, and in the presence or absence of the plasma. The invention also includes a reactor for aftertreatment of exhaust gases.

Whealton, John H. (Oak Ridge, TN); Hanson, Gregory R. (Clinton, TN); Storey, John M. (Oak Ridge, TN); Raridon, Richard J. (Oak Ridge, TN); Armfield, Jeffrey S. (Ypsilanti, MI); Bigelow, Timothy S. (Knoxville, TN); Graves, Ronald L. (Knoxville, TN)

2002-01-01T23:59:59.000Z

292

Reactivity Control Schemes for Fast Spectrum Space Nuclear Reactors  

Science Conference Proceedings (OSTI)

Several different reactivity control schemes are considered for future space nuclear reactor power systems. Each of these control schemes uses a combination of boron carbide absorbers and/or beryllium oxide reflectors to achieve sufficient reactivity swing to keep the reactor subcritical during launch and to provide sufficient excess reactivity to operate the reactor over its expected 7–15 year lifetime. The size and shape of the control system directly impacts the size and mass of the space reactor's reflector and shadow shield

Aaron E. Craft; Jeffrey C. King

2008-01-01T23:59:59.000Z

293

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)

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...

American Society for Testing and Materials. Philadelphia

2002-01-01T23:59:59.000Z

294

SAMFT3D: Single-phase and multiphase flow and transport in 3 dimensions. Version 1.0, Documentation and user`s guide  

Science Conference Proceedings (OSTI)

SAMFT3D is a three-dimensional, finite element code designed to simulate single-phase and multiphase fluid flow and contaminant transport in porous media. This report documents the single-phase version of the code. The single-phase computational modules have been developed to simulate flow and solute transport in fully or variable saturated porous media. The formulation of the governing equations and the numerical procedures used in these modules are presented. The flow equation is approximated using the Galerkin finite element method. For variably saturated flow problems, nonlinearities due to unsaturated soil properties are treated using Picard or Newton-Raphson iterations. The contaminant transport simulation can account for advection, hydrodynamic dispersion, linear equilibrium sorption, and first-order degradation. Transport of a single component can be handled. The transport equation is approximated using a upstream weighted residual method. Several test problems are presented to verify the code and to demonstrate its utility. These problems range from single one-dimensional to complex three-dimensional problems. This document has been produced as a user`s manual. It contains brief information on the code structure along with detailed instructions for input data preparation and sample input and printed output for selected test problems. Also included are instructions for setting up a simulation run and restart procedures.

NONE

1991-09-01T23:59:59.000Z

295

High-resolution numerical methods for compressible multi-phase flow in hierarchical porous media. Progress report, September 1993--September 1994  

SciTech Connect

This is the second year in the proposed three-year effort to develop high-resolution numerical methods for multi-phase flow in hierarchical porous media. The issues being addressed in this research are: Computational efficiency: Field-scale simulation of enhanced oil recovery, whether for energy production or aquifer remediation, is typically highly under-resolved. This is because rock transport properties vary on many scales, and because current numerical methods have low resolution. Effective media properties: Since porous media are formed through complex geologic processes, they involve significant uncertainty and scale-dependence. Given this uncertainty, knowledge of ensemble averages of flow in porous media can be preferable to knowledge of flow in specific realizations of the reservoir. However, current models of effective properties do not represent the observed behavior very well. Relative permeability models present a good example of this problem. In practice, these models seldom provide realistic representations of hysteresis, interfacial tension effects or three-phase flow; there are no models that represent well all three effects simultaneously.

Trangenstein, J.A.

1994-03-15T23:59:59.000Z

296

Assessment of the Economic Potential of Microgrids for Reactive Power Supply  

E-Print Network (OSTI)

of Commercial Building Microgrids,” IEEE Transactions onEconomic Potential of Microgrids for Reactive Power Supplyof creating an incentive for microgrids to provide reactive

Appen, Jan von

2012-01-01T23:59:59.000Z

297

Synthesis of Sm-Fe-N Hard Magnets by Reactive Mechanical Milling  

Science Conference Proceedings (OSTI)

In this study, we have performed reactive mechanical milling on Sm2Fe17 alloy under hydrogen atmosphere. After reactive mechanical milling, the Sm2Fe17 ...

298

Photo of the Week: Reactive Ion Etching | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Reactive Ion Etching Reactive Ion Etching Photo of the Week: Reactive Ion Etching October 17, 2013 - 1:26pm Addthis Have you ever heard of Laue lenses? These multilayer lenses are used to focus high-intensity x-ray beams to show the details of nano material structures. In this photo, the drop-like domes were carved through a process called reactive ion etching, which produced the striped bubbles you see in the Laue lens. The prototype in this image helped scientists perfect the process of creating lenses so precise that scientists are able to focus x-rays to within a single nanometer. | Photo courtesy of Brookhaven National Laboratory. Have you ever heard of Laue lenses? These multilayer lenses are used to focus high-intensity x-ray beams to show the details of nano material

299

Radiation Chemistry of Ionic Liquids: Reactivity of Primary Species  

NLE Websites -- All DOE Office Websites (Extended Search)

Liquids: Reactivity of Primary Species Liquids: Reactivity of Primary Species James F. Wishart In "Ionic Liquids as Green Solvents: Progress and Prospects" Rogers, R. D. and Seddon, K. R. , Eds.; ACS Symp. Ser. 856, Ch. 31, pp. 381-395, American Chemical Society, Washington, DC, 2003. (ISBN 0-84123-856-1) [Information about the book] Abstract: An understanding of the radiation chemistry of ionic liquids is important for development of their applications in radioactive material processing and for the application of pulse radiolysis techniques to the general study of chemical reactivity in ionic liquids. The distribution of primary radiolytic species and their reactivities determine the yields of ultimate products and the radiation stability of a particular ionic liquid. This chapter introduces some principles of radiation chemistry and the

300

A-26: Nanoindentation Investigation of the Reactive Pulsed Laser ...  

Science Conference Proceedings (OSTI)

... of the Reactive Pulsed Laser Deposited Superconducting Niobium Nitride Thin Films. Author(s) ... A-33: Modeling of a Displacive Transformation within Continuous ... Dye-Sensitized Solar Cells by Introducing a TiN Nanocrystalline Thin Film.

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Pre-plated reactive diffusion-bonded battery electrode plaques  

SciTech Connect

A high strength, metallic fiber battery plaque is made using reactive diffusion bonding techniques, where a substantial amount of the fibers are bonded together by an iron-nickel alloy.

Maskalick, Nicholas J. (Pittsburgh, PA)

1984-01-01T23:59:59.000Z

302

Land Use and Reactive Nitrogen Discharge: Effects of Dietary Choices  

Science Conference Proceedings (OSTI)

Modern agriculture alters natural biological and geophysical processes, with magnitudes proportional to its spatial extent. Cultivation is also the main cause of artificially enhanced reactive nitrogen (Nr) availability in natural ecosystems. ...

Gidon Eshel; Pamela A. Martin; Esther E. Bowen

2010-12-01T23:59:59.000Z

303

Reactive Reserve Requirements and Optimal Allocation Among Resources  

Science Conference Proceedings (OSTI)

Voltage stability is a major concern in power system operation, and the need to maintain it limits power transfers in the prevailing open access environment. In a power system with significant induction motor loads, voltage instability can be manifested either in the form of delayed voltage recovery or voltage collapse. Inadequate reactive supply is a major factor in causing these problems. Reactive supply is an important ingredient in maintaining healthy power system voltages and facilitating power tran...

2010-12-01T23:59:59.000Z

304

(Electronic structure and reactivities of transition metal clusters)  

DOE Green Energy (OSTI)

The following are reported: theoretical calculations (configuration interaction, relativistic effective core potentials, polyatomics, CASSCF); proposed theoretical studies (clusters of Cu, Ag, Au, Ni, Pt, Pd, Rh, Ir, Os, Ru; transition metal cluster ions; transition metal carbide clusters; bimetallic mixed transition metal clusters); reactivity studies on transition metal clusters (reactivity with H{sub 2}, C{sub 2}H{sub 4}, hydrocarbons; NO and CO chemisorption on surfaces). Computer facilities and codes to be used, are described. 192 refs, 13 figs.

Not Available

1992-01-01T23:59:59.000Z

305

[Electronic structure and reactivities of transition metal clusters  

DOE Green Energy (OSTI)

The following are reported: theoretical calculations (configuration interaction, relativistic effective core potentials, polyatomics, CASSCF); proposed theoretical studies (clusters of Cu, Ag, Au, Ni, Pt, Pd, Rh, Ir, Os, Ru; transition metal cluster ions; transition metal carbide clusters; bimetallic mixed transition metal clusters); reactivity studies on transition metal clusters (reactivity with H{sub 2}, C{sub 2}H{sub 4}, hydrocarbons; NO and CO chemisorption on surfaces). Computer facilities and codes to be used, are described. 192 refs, 13 figs.

Not Available

1992-08-01T23:59:59.000Z

306

Reactive burn models and ignition & growth concept  

SciTech Connect

Plastic-bonded explosives are heterogeneous materials. Experimentally, shock initiation is sensitive to small amounts of porosity, due to the formation of hot spots (small localized regions of high temperature). This leads to the Ignition and Growth concept, introduced by Lee and Tarver in 1980, as the basis for reactive burn models. A homogeneized burn rate needs to account for three mesoscale physical effects (i) the density of burnt hot spots, which depends on the lead shock strength; (ii) the growth of the burn fronts triggered by hot spots, which depends on the local deflagration speed; (iii) a geometric factor that accounts for the overlap of deflagration wavelets from adjacent hot spots. These effects can be combined and the burn model defined by specifying the reaction progress variable {lambda}(t) as a function of a dimensionless reaction length {tau}{sub hs}(t)/{ell}{sub hs}, rather than by xpecifying an explicit burn rate. The length scale {ell}{sub hs} is the average distance between hot spots, which is proportional to [N{sub hs}(P{sub s})]{sup -1/3}, where N{sub hs} is the number density of hot spots activated by the lead shock. The reaction length {tau}{sub hs}(t) = {line_integral}{sub 0}{sup t} D(P(t'))dt' is the distance the burn front propagates from a single hot spot, where D is the deflagration speed and t is the time since the shock arrival. A key implementation issue is how to determine the lead shock strength in conjunction with a shock capturing scheme. They have developed a robust algorithm for this purpose based on the Hugoniot jump condition for the energy. The algorithm utilizes the time dependence of density, pressure and energy within each cell. The method is independent of the numerical dissipation used for shock capturing. It is local and can be used in one or more space dimensions. The burn model has a small number of parameters which can be calibrated to fit velocity gauge data from shock initiation experiments.

Menikoff, Ralph S [Los Alamos National Laboratory; Shaw, Milton S [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

307

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  

DOE Green Energy (OSTI)

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.

Anastasia Gribik; Doona Guillen, PhD; Daniel Ginosar, PhD

2008-09-01T23:59:59.000Z

308

Third (March 2006) Coring and Analysis of Zero-Valent Iron Permeable Reactive Barrier, Monticello, Utah  

Energy.gov (U.S. Department of Energy (DOE))

Third (March 2006) Coring and Analysis of Zero-Valent Iron Permeable Reactive Barrier, Monticello, Utah

309

Reactive behavior in object-oriented applications: an analysis and a research roadmap  

Science Conference Proceedings (OSTI)

Reactive applications are difficult to implement. Traditional solutions based on event systems and the Observer pattern have a number of inconveniences, but programmers bear them in return for the benefits of OO design. On the other hand, reactive approaches ... Keywords: functional-reactive programming, incremental computation, object-oriented programming, reactive programming

Guido Salvaneschi; Mira Mezini

2013-03-01T23:59:59.000Z

310

Ionic Liquids and Ionizing Radiation: Reactivity of Highly Energetic  

NLE Websites -- All DOE Office Websites (Extended Search)

Ionizing Radiation: Reactivity of Highly Energetic Ionizing Radiation: Reactivity of Highly Energetic Species James F. Wishart J. Phys. Chem. Lett. 1, 3225-3231 (2010). [Find paper at ACS Publications] or use ACS Articles on Request View the video on this Perspective article at The Journal of Physical Chemistry Letters (5:03) Selected for the ACS Special Virtual Issue on Ionic Liquids (March 2011). Abstract: Due to their unique properties, ionic liquids present many opportunities for basic research on the interactions of radiation with materials under conditions not previously available. At the same time, there are practical applied reasons for characterizing, understanding, and being able to predict how ionic-liquid-based devices and industrial-scale systems will perform under conditions of extreme reactivity, including radiation. This

311

Options for Control of Reactive Power by Distributed Photovoltaic Generators  

E-Print Network (OSTI)

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...

Sulc, Petr; Backhaus, Scott; Chertkov, Michael

2010-01-01T23:59:59.000Z

312

Internal structure, hygroscopic and reactive properties of mixed sodium  

NLE Websites -- All DOE Office Websites (Extended Search)

Internal structure, hygroscopic and Internal structure, hygroscopic and reactive properties of mixed sodium methanesulfonate-sodium chloride particles Internal structure, hygroscopic and reactive properties of mixed sodium methanesulfonate-sodium chloride particles Print Friday, 13 May 2011 00:00 Scientists recently combined experimental approaches and molecular dynamics modeling to gain new insights into the internal structure of sea salt particles and relate it to their fundamental chemical reactivity in the atmosphere. This research shows that surface enhancement or depletion of chemical components in marine particles can occur because of the difference in the chemical nature of the species. Because the atmospheric chemistry of the salt particles takes place at the gas-particle interface, understanding their complex surfaces provides new insights about their effect on the environment and climate change. Article Link.

313

OPF for reactive pricing studies on the NGC system  

SciTech Connect

Retail transmission services like those being provided by the National Grid Company (NGC) in England and Wales pose new challenges for the pricing of reactive power supply. A reactive power market approach has been proposed by NGC and continues to be evaluated. Such an approach includes a novel requirement for transmission constrained economic dispatch of VArs, a problem in the security constrained optimal power flow (OPF) class. The problem formulations handled by the OPF package in use could not accommodate NGC`s requirements. This paper describes the reactive pricing problem being addressed, the modeling requirements, and the resulting extensions made to the OPF formulation and package. It discusses the test results obtained to date on the NGC system.

Dandachi, N.H.; Rawlins, M.J. [National Grid Co., Sindlesham (United Kingdom). Control Technology Centre; Alsac, O.; Prais, M.; Stott, B. [PCA Corp., Mesa, AZ (United States)

1996-02-01T23:59:59.000Z

314

Method and apparatus for measuring reactivity of fissile material  

DOE Patents (OSTI)

Given are a method and apparatus for measuring nondestructively and noninvasively (i.e., using no internal probing) the burnup, reactivity, or fissile content of any material which emits neutrons and which has fissionable components. The assay is accomplished by altering the return flux of neutrons into the fuel assembly by means of changing the reflecting material. The existing passive neutron emissions in the material being assayed are used as the source of interrogating neutrons. Two measurements of either emitted neutron or emitted gamma-ray count rates are made and are then correlated to either reactivity, burnup, or fissionable content of the material being assayed, thus providing a measurement of either reactivity, burnup, or fissionable content of the material being assayed. Spent fuel which has been freshly discharged from a reactor can be assayed using this method and apparatus. Precisions of 1000 MWd/tU appear to be feasible.

Lee, D.M.; Lindquist, L.O.

1982-09-07T23:59:59.000Z

315

Effect of superbanana diffusion on fusion reactivity in stellarators  

Science Conference Proceedings (OSTI)

Fusion reactivity is usually obtained using a Maxwellian distribution. However, energy-dependent radial diffusion can modify the energy distribution. Superbanana diffusion is energy-dependent and occurs in nonaxisymmetric magnetic confinement devices, such as stellarators, because of ripple-trapped particles which can take large steps between collisions. In this paper, the D-T fusion reactivity is calculated using a non-Maxwellian energy distribution obtained by solving the Fokker-Planck equation numerically, including radial superbanana diffusion as well as energy scattering. The ions in the tail of the distribution, with energies larger than thermal, which are most needed for fusion, are depleted by superbanana diffusion. In this paper, it is shown that the D-T fusion reactivity is reduced by tail ion depletion due to superbanana diffusion, by roughly a factor of 0.5 for the parameters used in the calculation.

Hinton, Fred L. [Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, California 92093-0424 (United States)

2012-08-15T23:59:59.000Z

316

Enhanced durability and reactivity for zinc ferrite desulfurization sorbent  

Science Conference Proceedings (OSTI)

AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

Jha, M.C.; Berggren, M.H.

1989-05-02T23:59:59.000Z

317

Dielectric covered hairpin probe for its application in reactive plasmas  

Science Conference Proceedings (OSTI)

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.

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

318

Use of TOUGHREACT to Simulate Effects of Fluid Chemistry onInjectivity in Fractured Geothermal Reservoirs with High Ionic StrengthFluids  

SciTech Connect

Recent studies suggest that mineral dissolution/precipitation and clay swelling effects could have a major impact on the performance of hot dry rock (HDR) and hot fractured rock (HFR) reservoirs. A major concern is achieving and maintaining adequate injectivity, while avoiding the development of preferential short-circuiting flow paths. A Pitzer ionic interaction model has been introduced into the publicly available TOUGHREACT code for solving non-isothermal multi-phase reactive geochemical transport problems under conditions of high ionic strength, expected in typical HDR and HFR systems. To explore chemically-induced effects of fluid circulation in these systems, we examine ways in which the chemical composition of reinjected waters can be modified to improve reservoir performance. We performed a number of coupled thermo-hydrologic-chemical simulations in which the fractured medium was represented by a one-dimensional MINC model (multiple interacting continua). Results obtained with the Pitzer activity coefficient model were compared with those using an extended Debye-Hueckel equation. Our simulations show that non-ideal activity effects can be significant even at modest ionic strength, and can have major impacts on permeability evolution in injection-production systems. Alteration of injection water chemistry, for example by dilution with fresh water, can greatly alter precipitation and dissolution effects, and can offer a powerful tool for operating hot dry rock and hot fractured rock reservoirs in a sustainable manner.

Xu, Tianfu; Zhang, Guoxiang; Pruess, Karsten

2005-02-09T23:59:59.000Z

319

Local control of reactive power by distributed photovoltaic generators  

SciTech Connect

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.

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

320

Development of a model for reactive emissions from industrial stacks  

Science Conference Proceedings (OSTI)

We have developed a model, CAPAS, capable of estimating short-term concentrations of primary and secondary pollutants resulting from point source emissions. The model is designed to simulate the complex interaction of plume dispersion and non-linear ... Keywords: Air pollutants, Dispersion models, Non-linear chemistry, Plume reactivity, Stiff solvers

Luis E. Olcese; Beatriz M. Toselli

2005-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Reactive transport in surface sediments I. Mexity and software quality  

Science Conference Proceedings (OSTI)

Analysis of three recent diagenetic model codes (OMEXDIA, CANDI and STEADYSED) revealed that codes have a rigid, static and problem-specific character, leaving little autonomy for the application user. The resulting lack of flexibility and extensibility, ... Keywords: early diagenesis, object-oriented design, problem-solving environment, reactive transport modelling, software quality assurance

Filip J. R. Meysman; Jack J. Middelburg; Peter M. J. Herman; Carlo H. R. Heip

2003-04-01T23:59:59.000Z

322

Modeling and Verification of Reactive Systems using Rebeca  

Science Conference Proceedings (OSTI)

Actor-based modeling has been successfully applied to the representation of concurrent and distributed systems. Besides having an appropriate and efficient way for modeling these systems, one needs a formal verification approach for ensuring their correctness. ... Keywords: actor model, compositional verification, model checking, property preserving abstraction, reactive systems

Marjan Sirjani; Ali Movaghar; Amin Shali; Frank S. de Boer

2004-12-01T23:59:59.000Z

323

Method and apparatus for measuring reactivity of fissile material  

DOE Patents (OSTI)

Given are a method and apparatus for measuring nondestructively and non-invasively (i.e., using no internal probing) the burnup, reactivity, or fissile content of any material which emits neutrons and which has fissionable components. No external neutron-emitting interrogation source or fissile material is used and no scanning is required, although if a profile is desired scanning can be used. As in active assays, here both reactivity and content of fissionable material can be measured. The assay is accomplished by altering the return flux of neutrons into the fuel assembly. The return flux is altered by changing the reflecting material. The existing passive neutron emissions in the material being assayed are used as the source of interrogating neutrons. Two measurements of either emitted neutron or emitted gamma-ray count rates are made and are then correlated to either reactivity, burnup, or fissionable content of the material being assayed, thus providing a measurement of either reactivity, burnup, or fissionable content of the material being assayed. Spent fuel which has been freshly discharged from a reactor can be assayed using this method and apparatus. Precisions of 1000 MWd/tU appear to be feasible.

Lee, David M. (Los Alamos, NM); Lindquist, Lloyd O. (Santa Fe, NM)

1985-01-01T23:59:59.000Z

324

Enhanced durability and reactivity for zinc ferrite desulfurization sorbent  

Science Conference Proceedings (OSTI)

AMAX Research Development Center (AMAX R D) investigated methods for enhancing the reactivity and durability of zinc ferrite desulfurization sorbents. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For this program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such as size, strength, and specific surface area during 10 cycles of sulfidation and oxidation. Two base case sorbents, a spherical pellet and a cylindrical extrude used in related METC-sponsored projects, were used to provide a basis for the aimed enhancement in durability and reactivity. Sorbent performance was judged on the basis of physical properties, single particle kinetic studies based on thermogravimetric (TGA) techniques, and multicycle bench-scale testing of sorbents. A sorbent grading system was utilized to quantify the characteristics of the new sorbents prepared during the program. Significant enhancements in both reactivity and durability were achieved for the spherical pellet shape over the base case formulation. Overall improvements to reactivity and durability were also made to the cylindrical extrude shape. The primary variables which were investigated during the program included iron oxide type, zinc oxide:iron oxide ratio, inorganic binder concentration, organic binder concentration, and induration conditions. The effects of some variables were small or inconclusive. Based on TGA studies and bench-scale tests, induration conditions were found to be very significant.

Berggren, M.H.; Jha, M.C.

1989-10-01T23:59:59.000Z

325

Multiphase inverse modeling: An Overview  

DOE Green Energy (OSTI)

Inverse modeling is a technique to derive model-related parameters from a variety of observations made on hydrogeologic systems, from small-scale laboratory experiments to field tests to long-term geothermal reservoir responses. If properly chosen, these observations contain information about the system behavior that is relevant to the performance of a geothermal field. Estimating model-related parameters and reducing their uncertainty is an important step in model development, because errors in the parameters constitute a major source of prediction errors. This paper contains an overview of inverse modeling applications using the ITOUGH2 code, demonstrating the possibilities and limitations of a formalized approach to the parameter estimation problem.

Finsterle, S.

1998-03-01T23:59:59.000Z

326

MSA: multiphase specifically shared arrays  

Science Conference Proceedings (OSTI)

Shared address space (SAS) parallel programming models have faced difficulty scaling to large number of processors. Further, although in some cases SAS programs are easier to develop, in other cases they face difficulties due to a large number of race ...

Jayant DeSouza; Laxmikant V. Kalé

2004-09-01T23:59:59.000Z

327

Benchmark Experimental Database for Multiphase ...  

Science Conference Proceedings (OSTI)

... as liquid fuel spray combustion, coal slurry combustion ... density being under-reported. ... the measurements presented in this report because the ...

2011-09-22T23:59:59.000Z

328

Alternatives for Mending a Permeable Reactive Barrier at a Former Uranium  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Alternatives for Mending a Permeable Reactive Barrier at a Former Alternatives for Mending a Permeable Reactive Barrier at a Former Uranium Milling Site: Monticello, Utah Alternatives for Mending a Permeable Reactive Barrier at a Former Uranium Milling Site: Monticello, Utah Alternatives for Mending a Permeable Reactive Barrier at a Former Uranium Milling Site: Monticello, Utah Alternatives for Mending a Permeable Reactive Barrier at a Former Uranium Milling Site: Monticello, Utah More Documents & Publications Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium Mill Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium Mill Phase II: Performance Evaluation of Permeable Reactive Barriers and

329

Alternatives for Mending a Permeable Reactive Barrier at a Former Uranium  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Alternatives for Mending a Permeable Reactive Barrier at a Former Alternatives for Mending a Permeable Reactive Barrier at a Former Uranium Milling Site: Monticello, Utah Alternatives for Mending a Permeable Reactive Barrier at a Former Uranium Milling Site: Monticello, Utah Alternatives for Mending a Permeable Reactive Barrier at a Former Uranium Milling Site: Monticello, Utah Alternatives for Mending a Permeable Reactive Barrier at a Former Uranium Milling Site: Monticello, Utah More Documents & Publications Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium Mill Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium Mill Final Report Phase II: Performance Evaluation of Permeable Reactive

330

Catalytic and reactive polypeptides and methods for their preparation and use  

DOE Patents (OSTI)

Catalytic and reactive polypeptides include a binding site specific for a reactant or reactive intermediate involved in a chemical reaction of interest. The polypeptides further include at least one active functionality proximate the bi.

Schultz, Peter (Oakland, CA)

1993-01-01T23:59:59.000Z

331

Incorporation of plug in hybrid electric vehicle in the reactive power market  

Science Conference Proceedings (OSTI)

This paper incorporates plug in hybrid electric vehicle(PHEV) in the reactive power market. The PHEV capability curve is first extracted considering the operation limit of PHEV. In order to offer price in the reactive power market

H. Feshki Farahani; H. A. Shayanfar; M. S. Ghazizadeh

2012-01-01T23:59:59.000Z

332

Reactive Plasma-Aided Fabrication of ZnO for Solar Cells Applications  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2009. Symposium, Multifunctional Oxide. Presentation Title, Reactive Plasma-Aided Fabrication of ...

333

24 Hour Day-Ahead Reactive Power Forecasting and Optimal Scheduling  

Science Conference Proceedings (OSTI)

Reactive power management affects not only the system voltage profiles but also system efficiencies. Changes in the flow of reactive power have an influence on system losses. Reactive power forecasting and optimal scheduling of power system control elements can be conducted to efficiently and reliably transfer power across the system. The tool discussed in this report optimizes the power system to produce a security-constrained case, reduce losses, increase reactive reserve, and securely maintain ...

2013-12-29T23:59:59.000Z

334

Please cite this article in press as: Preisig, M., Prvost, J.H., Coupled multi-phase thermo-poromechanical effects. Case study: CO2 injection at In Salah, Algeria. Int. J. Greenhouse Gas Control (2011), doi:10.1016/j.ijggc.2010.12.006  

E-Print Network (OSTI)

-poromechanical effects. Case study: CO2 injection at In Salah, Algeria. Int. J. Greenhouse Gas Control (2011), doi:10 of Greenhouse Gas Control xxx (2011) xxx­xxx Contents lists available at ScienceDirect International Journal of Greenhouse Gas Control journal homepage: www.elsevier.com/locate/ijggc Coupled multi-phase thermo

Prevost, Jean-Herve

335

Efficient and Reliable Reactive Power Supply and Consumption -- Insights from an Integrated Program of Engineering and Economic Research  

E-Print Network (OSTI)

need to establish real-time prices for reactive power toWe find that nodal real-time prices for reactive power willfind that non-zero real-time prices for reactive power will

2008-01-01T23:59:59.000Z

336

Catalytic destruction of groundwater contaminants in reactive extraction wells  

DOE Green Energy (OSTI)

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.

McNab, Jr., Walt W. (Concord, CA); Reinhard, Martin (Stanford, CA)

2002-01-01T23:59:59.000Z

337

Modeling Routing Overhead Generated by Wireless Reactive Routing Protocols  

E-Print Network (OSTI)

In this paper, we have modeled the routing over- head generated by three reactive routing protocols; Ad-hoc On-demand Distance Vector (AODV), Dynamic Source Routing (DSR) and DYnamic MANET On-deman (DYMO). Routing performed by reactive protocols consists of two phases; route discovery and route maintenance. Total cost paid by a protocol for efficient routing is sum of the cost paid in the form of energy consumed and time spent. These protocols majorly focus on the optimization performed by expanding ring search algorithm to control the flooding generated by the mechanism of blind flooding. So, we have modeled the energy consumed and time spent per packet both for route discovery and route maintenance. The proposed framework is evaluated in NS-2 to compare performance of the chosen routing protocols.

Javaid, Nadeem; Javaid, Akmal; Malik, Shahzad A

2011-01-01T23:59:59.000Z

338

Tracking thermal fronts with temperature-sensitive, chemically reactive tracers  

DOE Green Energy (OSTI)

Los Alamos is developing tracer techniques using reactive chemicals to track thermal fronts in fractured geothermal reservoirs. If a nonadsorbing tracer flowing from the injection to production well chemically reacts, its reaction rate will be a strong function of temperature. Thus the extent of chemical reaction will be greatest early in the lifetime of the system, and less as the thermal front progresses from the injection to production well. Early laboratory experiments identified tracers with chemical kinetics suitable for reservoirs in the temperature range of 75 to 100/sup 0/C. Recent kinetics studies have focused on the kinetics of hydrolysis of derivatives of bromobenzene. This class of reactions can be used in reservoirs ranging in temperature from 150 to 275/sup 0/C, which is of greater interest to the geothermal industry. Future studies will include laboratory adsorption experiments to identify possibly unwanted adsorption on granite, development of sensitive analytical techniques, and a field demonstration of the reactive tracer concept.

Robinson, B.A.; Birdsell, S.A.

1987-01-01T23:59:59.000Z

339

Solid polymer battery electrolyte and reactive metal-water battery  

SciTech Connect

In one implementation, a reactive metal-water battery includes an anode comprising a metal in atomic or alloy form selected from the group consisting of periodic table Group 1A metals, periodic table Group 2A metals and mixtures thereof. The battery includes a cathode comprising water. Such also includes a solid polymer electrolyte comprising a polyphosphazene comprising ligands bonded with a phosphazene polymer backbone. The ligands comprise an aromatic ring containing hydrophobic portion and a metal ion carrier portion. The metal ion carrier portion is bonded at one location with the polymer backbone and at another location with the aromatic ring containing hydrophobic portion. The invention also contemplates such solid polymer electrolytes use in reactive metal/water batteries, and in any other battery.

Harrup, Mason K. (Idaho Falls, ID); Peterson, Eric S. (Idaho Falls, ID); Stewart, Frederick F. (Idaho Falls, ID)

2000-01-01T23:59:59.000Z

340

Application of genetic algorithms for optimal reactive power planning of doubly fed induction generators  

Science Conference Proceedings (OSTI)

This paper describes optimal reactive power control of a doubly fed induction generator (DFIG), which is widely used in a distributed generating plant. Although its structure is similar to that of induction motors, its reactive power control is more ... Keywords: doubly fed induction generator, genetic algorithms, optimal reactive power planning, optimization

P. Sangsarawut; A. Oonsivilai; T. Kulworawanichpong

2010-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Optimal reactive power planning of doubly fed induction generators using genetic algorithms  

Science Conference Proceedings (OSTI)

This paper describes optimal reactive power control of a doubly fed induction generator (DFIG), which is widely used in a distributed generating plant. Although its structure is similar to that of an induction motor, its reactive power control is more ... Keywords: doubly fed induction generator, genetic algorithms, optimal reactive power planning, optimization

P. Sangsarawut; A. Oonsivilai; T. Kulworawanichpong

2010-02-01T23:59:59.000Z

342

Optimal Reactive Power Planning of Radial Distribution Systems with Distributed Generation  

Science Conference Proceedings (OSTI)

The paper analyzes reactive power optimization problem in distribution system with wind power and PV generators. Reactive power optimization mathematical model including the active power loss, reactive power compensation capacity and static voltage margin ... Keywords: Distributed generation, Distributed Generation, Immune Algorithm, Cluster Evolutionary

Li Shengqi, Zeng Lilin, Li Yongan, He Zhengping

2013-01-01T23:59:59.000Z

343

Assessment of the Economic Potential of Microgrids for Reactive Power Supply  

E-Print Network (OSTI)

Assessment of the Economic Potential of Microgrids for Reactive Power Supply Jan von Appen1 , Chris. This paper outlines the economic potential of DERs coordinated in a microgrid to provide reactive power possibilities of creating an incentive for microgrids to provide reactive power. Index Terms ­ microgrids

344

Reactive Distillation for Esterification of Bio-based Organic Acids  

DOE Green Energy (OSTI)

The following is the final report of the three year research program to convert organic acids to their ethyl esters using reactive distillation. This report details the complete technical activities of research completed at Michigan State University for the period of October 1, 2003 to September 30, 2006, covering both reactive distillation research and development and the underlying thermodynamic and kinetic data required for successful and rigorous design of reactive distillation esterification processes. Specifically, this project has led to the development of economical, technically viable processes for ethyl lactate, triethyl citrate and diethyl succinate production, and on a larger scale has added to the overall body of knowledge on applying fermentation based organic acids as platform chemicals in the emerging biorefinery. Organic acid esters constitute an attractive class of biorenewable chemicals that are made from corn or other renewable biomass carbohydrate feedstocks and replace analogous petroleum-based compounds, thus lessening U.S. dependence on foreign petroleum and enhancing overall biorefinery viability through production of value-added chemicals in parallel with biofuels production. Further, many of these ester products are candidates for fuel (particularly biodiesel) components, and thus will serve dual roles as both industrial chemicals and fuel enhancers in the emerging bioeconomy. The technical report from MSU is organized around the ethyl esters of four important biorenewables-based acids: lactic acid, citric acid, succinic acid, and propionic acid. Literature background on esterification and reactive distillation has been provided in Section One. Work on lactic acid is covered in Sections Two through Five, citric acid esterification in Sections Six and Seven, succinic acid in Section Eight, and propionic acid in Section Nine. Section Ten covers modeling of ester and organic acid vapor pressure properties using the SPEAD (Step Potential Equilibrium and Dynamics) method.

Fields, Nathan; Miller, Dennis J.; Asthana, Navinchandra S.; Kolah, Aspi K.; Vu, Dung; Lira, Carl T.

2008-09-23T23:59:59.000Z

345

Dynamics of inelastic and reactive gas-surface collisions  

DOE Green Energy (OSTI)

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.

Smoliar, L.A.

1995-04-01T23:59:59.000Z

346

Options for Control of Reactive Power by Distributed Photovoltaic Generators  

E-Print Network (OSTI)

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.

Petr Sulc; Konstantin Turitsyn; Scott Backhaus; Michael Chertkov

2010-08-04T23:59:59.000Z

347

Conversion of carboxylate salts to carboxylic acids via reactive distillation  

E-Print Network (OSTI)

The purpose of this study is to convert carboxylate salts (e.g. calcium acetate, propionate, and butyrate) into carboxylic acids (e.g., acetic, propionic, and butyric acids). The carboxylate salts can be produced from wastes, such as paper fines, 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 culture of microorganisms derived from cattle rumen or anaerobic waste treatment facilities. The paper fines and municipal solid waste provide energy, whereas the industrial biosludge and sewage sludge provide nutrients for the microorganisms. The calcium carboxylate salts are concentrated and reacted with a low-molecular-weight tertiary amine and carbon dioxide to precipitate calcium carbonate. In a distillation column, the low-molecular-weight amine carboxylate reacts with a high-molecular-weight tertiary amine allowing the low-molecular-weight amine to be recovered from the top of the column. The resulting high-molecular-weight amine carboxylate is converted to amine and carboxylic acid in a reactive distillation column. This project focuses on the conversion of the carboxylate salts produced via fermentation into their corresponding acids via reactive distillation. The primary objective is to determine the optimal operating conditions of the distillation. A secondary objective is to optimize the precipitation step in the recovery process.

Williamson, Shelly Ann

2000-01-01T23:59:59.000Z

348

Dynamic Reactive Power Control of Isolated Power Systems  

E-Print Network (OSTI)

This dissertation presents dynamic reactive power control of isolated power systems. Isolated systems include MicroGrids in islanded mode, shipboard power systems operating offshore, or any other power system operating in islanded mode intentionally or due to a fault. Isolated power systems experience fast transients due to lack of an infinite bus capable of dictating the voltage and frequency reference. This dissertation only focuses on reactive control of islanded MicroGrids and AC/DC shipboard power systems. The problem is tackled using a Model Predictive Control (MPC) method, which uses a simplified model of the system to predict the voltage behavior of the system in future. The MPC method minimizes the voltage deviation of the predicted bus voltage; therefore, it is inherently robust and stable. In other words, this method can easily predict the behavior of the system and take necessary control actions to avoid instability. Further, this method is capable of reaching a smooth voltage profile and rejecting possible disturbances in the system. The studied MicroGrids in this dissertation integrate intermittent distributed energy resources such as wind and solar generators. These non-dispatchable sources add to the uncertainty of the system and make voltage and reactive control more challenging. The model predictive controller uses the capability of these sources and coordinates them dynamically to achieve the voltage goals of the controller. The MPC controller is implemented online in a closed control loop, which means it is self-correcting with the feedback it receives from the system.

Falahi, Milad

2012-12-01T23:59:59.000Z

349

Application of molten salts in pyrochemical processing of reactive metals  

Science Conference Proceedings (OSTI)

Various mixes of chloride and fluoride salts are used as the media for conducting pyrochemical processes in the production and purification of reactive metals. These processes generate a significant amount of contaminated waste that has to be treated for recycling or disposal. Molten calcium chloride based salt systems have been used in this work to electrolytically regenerate calcium metal from calcium oxide for the in situ reduction of reactive metal oxides. The recovery of calcium is characterized by the process efficiency to overcome back reactions in the electrowinning cell. A thermodynamic analysis, based on fundamental rate theory, has been performed to understand the process parameters controlling the metal deposition, rate, behavior of the ceramic anode-sheath and influence of the back-reactions. It has been observed that the deposition of calcium is dependent on the ionic diffusion through the sheath. It has also been evidenced that the recovered calcium is completely lost through the back-reactions in the absence of a sheath. A practical scenario has also been presented where the electrowon metal can be used in situ as a reductant to reduce another reactive metal oxide.

Mishra, B.; Olson, D.L. (Colorado School of Mines, Golden, CO (United States). Kroll Inst. for Extractive Metallurgy); Averill, W.A. (EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant)

1992-01-01T23:59:59.000Z

350

Fluid-rock interaction: A reactive transport approach  

SciTech Connect

Fluid-rock interaction (or water-rock interaction, as it was more commonly known) is a subject that has evolved considerably in its scope over the years. Initially its focus was primarily on interactions between subsurface fluids of various temperatures and mostly crystalline rocks, but the scope has broadened now to include fluid interaction with all forms of subsurface materials, whether they are unconsolidated or crystalline ('fluid-solid interaction' is perhaps less euphonious). Disciplines that previously carried their own distinct names, for example, basin diagenesis, early diagenesis, metamorphic petrology, reactive contaminant transport, chemical weathering, are now considered to fall under the broader rubric of fluid-rock interaction, although certainly some of the key research questions differ depending on the environment considered. Beyond the broadening of the environments considered in the study of fluid-rock interaction, the discipline has evolved in perhaps an even more important way. The study of water-rock interaction began by focusing on geochemical interactions in the absence of transport processes, although a few notable exceptions exist (Thompson 1959; Weare et al. 1976). Moreover, these analyses began by adopting a primarily thermodynamic approach, with the implicit or explicit assumption of equilibrium between the fluid and rock. As a result, these early models were fundamentally static rather than dynamic in nature. This all changed with the seminal papers by Helgeson and his co-workers (Helgeson 1968; Helgeson et al. 1969) wherein the concept of an irreversible reaction path was formally introduced into the geochemical literature. In addition to treating the reaction network as a dynamically evolving system, the Helgeson studies introduced an approach that allowed for the consideration of a multicomponent geochemical system, with multiple minerals and species appearing as both reactants and products, at least one of which could be irreversible. Helgeson's pioneering approach was given a more formal kinetic basis (including the introduction of real time rather than reaction progress as the independent variable) in subsequent studies (Lasaga 1981; Aagaard and Helgeson 1982; Lasaga 1984). The reaction path approach can be used to describe chemical processes in a batch or closed system (e.g., a laboratory beaker), but such systems are of limited interest in the Earth sciences where the driving force for most reactions is transport. Lichtner (1988) clarified the application of the reaction path models to water-rock interaction involving transport by demonstrating that they could be used to describe pure advective transport through porous media. By adopting a reference frame which followed the fluid packet as it moved through the medium, the reaction progress variable could be thought of as travel time instead. Multi-component reactive transport models that could treat any combination of transport and biogeochemical processes date back to the early 1980s. Berner and his students applied continuum reactive transport models to describe processes taking place during the early diagenesis of marine sediments (Berner 1980). Lichtner (1985) outlined much of the basic theory for a continuum model for multicomponent reactive transport. Yeh and Tripathi (1989) also presented the theoretical and numerical basis for the treatment of reactive contaminant transport. Steefel and Lasaga (1994) presented a reactive flow and transport model for nonisothermal, kinetically-controlled water-rock interaction and fracture sealing in hydrothermal systems based on simultaneous numerical solution of both reaction and transport This chapter begins with a review of the important transport processes that affect or even control fluid-rock interaction. This is followed by a general introduction to the governing equations for reactive transport, which are broadly applicable to both qualitative and quantitative interpretations of fluid-rock interactions. This framework is expanded through a discussion of specific topics that are the f

Steefel, C.; Maher, K.

2009-04-01T23:59:59.000Z

351

PACKAGE (Plasma Analysis, Chemical Kinetics and Generator Efficiency): a computer program for the calculation of partial chemical equilibrium/partial chemical rate controlled composition of multiphased mixtures under one dimensional steady flow  

SciTech Connect

The NASA CEC Code was the starting point for PACKAGE, whose function is to evaluate the composition of a multiphase combustion product mixture under the following chemical conditions: (1) total equilibrium with pure condensed species; (2) total equilibrium with ideal liquid solution; (3) partial equilibrium/partial finite rate chemistry; and (4) fully finite rate chemistry. The last three conditions were developed to treat the evolution of complex mixtures such as coal combustion products. The thermodynamic variable pairs considered are either pressure (P) and enthalpy, P and entropy, at P and temperature. Minimization of Gibbs free energy is used. This report gives detailed discussions of formulation and input/output information used in the code. Sample problems are given. The code development, description, and current programming constraints are discussed. (DLC)

Yousefian, V.; Weinberg, M.H.; Haimes, R.

1980-02-01T23:59:59.000Z

352

Performance of a Permeable Reactive Barrier Using Granular Zero-Valent  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Performance of a Permeable Reactive Barrier Using Granular Performance of a Permeable Reactive Barrier Using Granular Zero-Valent Iron: FY 2004 Annual Report Durango, Colorado, Disposal Site Performance of a Permeable Reactive Barrier Using Granular Zero-Valent Iron: FY 2004 Annual Report Durango, Colorado, Disposal Site Performance of a Permeable Reactive Barrier Using Granular Zero-Valent Iron: FY 2004 Annual Report Durango, Colorado, Disposal Site Performance of a Permeable Reactive Barrier Using Granular Zero-Valent Iron: FY 2004 Annual Report Durango, Colorado, Disposal Site More Documents & Publications Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing

353

Reactive dynamics of inertial particles in nonhyperbolic chaotic flows  

E-Print Network (OSTI)

Anomalous kinetics of infective (e.g., autocatalytic) reactions in open, nonhyperbolic chaotic flows are important for many applications in biological, chemical, and environmental sciences. We present a scaling theory for the singular enhancement of the production caused by the universal, underlying fractal patterns. The key dynamical invariant quantities are the effective fractal dimension and effective escape rate, which are primarily determined by the hyperbolic components of the underlying dynamical invariant sets. The theory is general as it includes all previously studied hyperbolic reactive dynamics as a special case. We introduce a class of dissipative embedding maps for numerical verification.

Adilson E. Motter; Ying-Cheng Lai; Celso Grebogi

2003-11-26T23:59:59.000Z

354

Reactive multilayer synthesis of hard ceramic foils and films  

DOE Patents (OSTI)

Disclosed is method for synthesizing hard ceramic materials such as carbides, borides and aluminides, particularly in the form of coatings provided on another material so as to improve the wear and abrasion performance of machine tools, for example. Method involves the sputter deposition of alternating layers of reactive metals with layers of carbon, boron, or aluminum and the subsequent reaction of the multilayered structure to produce a dense crystalline ceramic. The material can be coated on a substrate or formed as a foil which can be coiled as a tape for later use.

Makowiecki, D.M.; Holt, J.B.

1993-12-31T23:59:59.000Z

355

Reactive sticking coefficients for silane and disilane on polycrystalline silicon  

SciTech Connect

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.

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

1988-04-15T23:59:59.000Z

356

Evaluating advanced LMR (liquid metal reactor) reactivity feedbacks using SSC  

Science Conference Proceedings (OSTI)

Analyses of the PRISM and SAFR Liquid Metal Reactors with SSC are discussed from a safety and licensing perspective. The PRISM and SAFR reactors with metal fuel are designed for inherent shutdown responses to loss-of-flow and loss-of-heat-sink events. The demonstration of this technology was performed by EBR-II during experiments in April 1986 by ANL (Planchon, et al.). Response to postulated TOPs (control rod withdrawal) are made acceptable largely by reducing reactivity swings, and therefore minimizing the size of possible ractivity insertions. Analyses by DOE and the contractors GE, RI, and ANL take credit for several reactivity feedback mechanisms during transient calculations. These feedbacks include Doppler, sodium density, and thermal expansion of the grid plates, the load pads, the fuel (axial) and the control rod which are now factored into the BNL SSC analyses. The bowing feedback mechanism is not presently modeled in the SSC due to its complexity and subsequent large uncertainty. The analysis is conservative by not taking credit for this negative feedback mechanism. Comparisons of BNL predictions with DOE contractors are provided.

Slovik, G.C.; Van Tuyle, G.J.; Kennett, R.J.; Cheng, H.S.

1988-01-01T23:59:59.000Z

357

Optimization of reactive distillation processes with simulated annealing  

E-Print Network (OSTI)

A simulated annealing-based algorithm (MSIMPSA) suitable for the optimization of mixed integer non-linear programming (MINLP) problems was applied to the synthesis of a non-equilibrium reactive distillation column. A simulation model based on an extension of conventional distillation is proposed for the simulation step of the optimization problem. In the case of ideal vapor}liquid equilibrium, the simulation results are similar to those obtained by Ciric and Gu (1994, AIChE Journal, 40(9), 1479) using the GAMS environment and to those obtained with the AspenPlus modular simulator. The optimization results are also similar to those previously reported and similar to those using an adaptive random search algorithm (MSGA). The optimizations were also performed with non-ideal vapor}liquid equilibrium, considering either distributed feed and reaction trays or single feed and reaction tray. The results show that the optimized objective function values are very similar, and mostly independent of the number of trays and of the reaction distribution. It is shown that the proposed simulation/optimization equation-oriented environments are capable of providing optimized solutions which are close to the global optimum, and reveal its adequacy for the optimization of reactive distillation

M. F. Cardoso; R. L. Salcedo; S. Feyo De Azevedo; D. Barbosa

1999-01-01T23:59:59.000Z

358

Hybrid nuclear reactor grey rod to obtain required reactivity worth  

DOE Patents (OSTI)

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.

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

359

Coordination of reactive power scheduling in a multi-area power system operated by independent utilities.  

E-Print Network (OSTI)

??This thesis addresses the problem of reactive power scheduling in a power system with several areas controlled by independent transmission system operators (TSOs). To design… (more)

Phulpin, Yannick

360

Assessment of the Economic Potential of Microgrids for Reactive Power Supply  

E-Print Network (OSTI)

Group, October 2010. [7] Microgrid Symposiums, Berkeley (compensation ranges from a microgrid cost perspective forsystem wide impacts of microgrid participation in reactive

Appen, Jan von

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Simulations of Deflagration-to-Detonation Transition in Reactive Gases |  

NLE Websites -- All DOE Office Websites (Extended Search)

numerically generated pseudo-schlieren image numerically generated pseudo-schlieren image Weak ignition behind a reflected Mach=1.5 shock in a stoichiometric hydrogen-oxygen mixture at 0.1 atm initial pressure. Picture shows a numerically generated pseudo-schlieren image of the onset of a detonation in a turbulent boundary layer. Alexei Khokhlov, University of Chicago; Charles Bacon, Argonne National Laboratory, Joanna Austin, Andrew Knisely, University of Illinois at Urbanna-Champaign Simulations of Deflagration-to-Detonation Transition in Reactive Gases PI Name: Alexei Khokhlov PI Email: ajk@oddjob.uchicago.edu Institution: The University of Chicago Allocation Program: INCITE Allocation Hours at ALCF: 130 Million Year: 2013 Research Domain: Chemistry Hydrogen is an abundant, environmentally friendly fuel with the potential

362

Reactive gas atomization processing for Fe-based ODS alloys  

Science Conference Proceedings (OSTI)

Gas atomization reaction synthesis was employed as a simplified method for processing oxide dispersion forming precursor Fe-based powders (e.g., Fe-Cr-Y-Hf). During this process a reactive atomization gas (i.e., Ar-O{sub 2}) was used to oxidize the powder surfaces during primary break-up and rapid solidification of the molten alloy. This resulted in envelopment of the powders by an ultra-thin (t dispersion strengthened microstructures were engineered from different powder particle size ranges, illustrating microstructural control as a function of particle solidification rate. Additionally, preliminary thermal-mechanical processing was used to develop a fine scale dislocation substructure for ultimate strengthening of the alloy.

Rieken, J.R.; Anderson, I.E.; Kramer, M.J.; Odette, G.R.; Stergarc, E.; Haney, E.

2011-08-08T23:59:59.000Z

363

Distributed control for optimal reactive power compensation in smart microgrids  

E-Print Network (OSTI)

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.

Bolognani, Saverio

2011-01-01T23:59:59.000Z

364

REACTIVITY OF RESORCINOL FORMALDEHYDE RESIN WITH NITRIC ACID  

Science Conference Proceedings (OSTI)

Solid-state infrared spectroscopy, differential scanning calorimetry, and elemental analysis have been used to evaluate the reactivity of resorcinol formaldehyde resin with nitric acid and characterize the solid product. Two distinct reactions were identified within the temperature range 25-55 C. The first reaction is primarily associated with resin nitration, while the second involves bulk oxidation and degradation of the polymer network leading to dissolution and off-gassing. Reaction was confirmed with nitric acid concentrations as low as 3 M at 25 C applied temperature and 0.625 M at 66 C. Although a nitrated resin product can be isolated under appropriate experimental conditions, calorimetry testing indicates no significant hazard associated with handling the dry material.

King, W; Fernando Fondeur, F; Bill Wilmarth, B; Myra Pettis, M; Shirley Mccollum, S

2006-06-14T23:59:59.000Z

365

Anode reactive bleed and injector shift control strategy  

DOE Patents (OSTI)

A system and method for correcting a large fuel cell voltage spread for a split sub-stack fuel cell system. The system includes a hydrogen source that provides hydrogen to each split sub-stack and bleed valves for bleeding the anode side of the sub-stacks. The system also includes a voltage measuring device for measuring the voltage of each cell in the split sub-stacks. The system provides two levels for correcting a large stack voltage spread problem. The first level includes sending fresh hydrogen to the weak sub-stack well before a normal reactive bleed would occur, and the second level includes sending fresh hydrogen to the weak sub-stack and opening the bleed valve of the other sub-stack when the cell voltage spread is close to stack failure.

Cai, Jun [Rochester, NY; Chowdhury, Akbar [Pittsford, NY; Lerner, Seth E [Honeoye Falls, NY; Marley, William S [Rush, NY; Savage, David R [Rochester, NY; Leary, James K [Rochester, NY

2012-01-03T23:59:59.000Z

366

Transparent electrical conducting films by activated reactive evaporation  

DOE Patents (OSTI)

Process and apparatus for producing transparent electrical conducting thin films by activated reactive evaporation is disclosed. Thin films of low melting point metals and alloys, such as indium oxide and indium oxide doped with tin, are produced by physical vapor deposition. The metal or alloy is vaporized by electrical resistance heating in a vacuum chamber, oxygen and an inert gas such as argon are introduced into the chamber, and vapor and gas are ionized by a beam of low energy electrons in a reaction zone between the resistance heater and the substrate. There is a reaction between the ionized oxygen and the metal vapor resulting in the metal oxide which deposits on the substrate as a thin film which is ready for use without requiring post deposition heat treatment. 1 fig.

Bunshah, R.; Nath, P.

1982-06-22T23:59:59.000Z

367

Transparent electrical conducting films by activated reactive evaporation  

DOE Patents (OSTI)

Process and apparatus for producing transparent electrical conducting thin films by activated reactive evaporation. Thin films of low melting point metals and alloys, such as indium oxide and indium oxide doped with tin, are produced by physical vapor deposition. The metal or alloy is vaporized by electrical resistance heating in a vacuum chamber, oxygen and an inert gas such as argon are introduced into the chamber, and vapor and gas are ionized by a beam of low energy electrons in a reaction zone between the resistance heater and the substrate. There is a reaction between the ionized oxygen and the metal vapor resulting in the metal oxide which deposits on the substrate as a thin film which is ready for use without requiring post deposition heat treatment.

Bunshah, Rointan (Los Angeles, CA); Nath, Prem (Troy, MI)

1982-01-01T23:59:59.000Z

368

Advanced hydraulic fracturing methods to create in situ reactive barriers  

Science Conference Proceedings (OSTI)

This article describes the use of hydraulic fracturing to increase permeability in geologic formations where in-situ remedial action of contaminant plumes will be performed. Several in-situ treatment strategies are discussed including the use of hydraulic fracturing to create in situ redox zones for treatment of organics and inorganics. Hydraulic fracturing methods offer a mechanism for the in-situ treatment of gently dipping layers of reactive compounds. Specialized methods using real-time monitoring and a high-energy jet during fracturing allow the form of the fracture to be influenced, such as creation of assymmetric fractures beneath potential sources (i.e. tanks, pits, buildings) that should not be penetrated by boring. Some examples of field applications of this technique such as creating fractures filled with zero-valent iron to reductively dechlorinate halogenated hydrocarbons, and the use of granular activated carbon to adsorb compounds are discussed.

Murdoch, L. [FRX Inc., Cincinnati, OH (United States)]|[Clemson Univ., SC (United States). Dept. of Geological Sciences; Siegrist, B.; Meiggs, T. [Oak Ridge National Lab., TN (United States)] [and others

1997-12-31T23:59:59.000Z

369

Sensitivity and uncertainty analysis applied to the JHR reactivity prediction  

SciTech Connect

The on-going AMMON program in EOLE reactor at CEA Cadarache (France) provides experimental results to qualify the HORUS-3D/N neutronics calculation scheme used for the design and safety studies of the new Material Testing Jules Horowitz Reactor (JHR). This paper presents the determination of technological and nuclear data uncertainties on the core reactivity and the propagation of the latter from the AMMON experiment to JHR. The technological uncertainty propagation was performed with a direct perturbation methodology using the 3D French stochastic code TRIPOLI4 and a statistical methodology using the 2D French deterministic code APOLLO2-MOC which leads to a value of 289 pcm (1{sigma}). The Nuclear Data uncertainty propagation relies on a sensitivity study on the main isotopes and the use of a retroactive marginalization method applied to the JEFF 3.1.1 {sup 27}Al evaluation in order to obtain a realistic multi-group covariance matrix associated with the considered evaluation. This nuclear data uncertainty propagation leads to a K{sub eff} uncertainty of 624 pcm for the JHR core and 684 pcm for the AMMON reference configuration core. Finally, transposition and reduction of the prior uncertainty were made using the Representativity method which demonstrates the similarity of the AMMON experiment with JHR (the representativity factor is 0.95). The final impact of JEFF 3.1.1 nuclear data on the Begin Of Life (BOL) JHR reactivity calculated by the HORUS-3D/N V4.0 is a bias of +216 pcm with an associated posterior uncertainty of 304 pcm (1{sigma}). (authors)

Leray, O.; Vaglio-Gaudard, C.; Hudelot, J. P.; Santamarina, A.; Noguere, G. [CEA, DER, SPRC, F-13108 St Paul-Lez-Durance (France); Di-Salvo, J. [CEA, DER, SPEx, F-13108 St Paul-Lez-Durance (France)

2012-07-01T23:59:59.000Z

370

A UNIFIED MONTE CARLO TREATMENT OF GAS-GRAIN CHEMISTRY FOR LARGE REACTION NETWORKS. II. A MULTIPHASE GAS-SURFACE-LAYERED BULK MODEL  

SciTech Connect

The observed gas-phase molecular inventory of hot cores is believed to be significantly impacted by the products of chemistry in interstellar ices. In this study, we report the construction of a full macroscopic Monte Carlo model of both the gas-phase chemistry and the chemistry occurring in the icy mantles of interstellar grains. Our model treats icy grain mantles in a layer-by-layer manner, which incorporates laboratory data on ice desorption correctly. The ice treatment includes a distinction between a reactive ice surface and an inert bulk. The treatment also distinguishes between zeroth- and first-order desorption, and includes the entrapment of volatile species in more refractory ice mantles. We apply the model to the investigation of the chemistry in hot cores, in which a thick ice mantle built up during the previous cold phase of protostellar evolution undergoes surface reactions and is eventually evaporated. For the first time, the impact of a detailed multilayer approach to grain mantle formation on the warm-up chemistry is explored. The use of a multilayer ice structure has a mixed impact on the abundances of organic species formed during the warm-up phase. For example, the abundance of gaseous HCOOCH{sub 3} is lower in the multilayer model than in previous grain models that do not distinguish between layers (so-called two phase models). Other gaseous organic species formed in the warm-up phase are affected slightly. Finally, we find that the entrapment of volatile species in water ice can explain the two-jump behavior of H{sub 2}CO previously found in observations of protostars.

Vasyunin, A. I. [Department of Chemistry, The University of Virginia, Charlottesville, VA (United States)] [Department of Chemistry, The University of Virginia, Charlottesville, VA (United States); Herbst, Eric, E-mail: anton.vasyunin@gmail.com, E-mail: eh2ef@virginia.edu [Departments of Chemistry, Astronomy, and Physics, The University of Virginia, Charlottesville, VA (United States)] [Departments of Chemistry, Astronomy, and Physics, The University of Virginia, Charlottesville, VA (United States)

2013-01-10T23:59:59.000Z

371

Modeling of concentrated aqueous solutions: Efficient implementation of Pitzer equations in geochemical and reactive transport models  

Science Conference Proceedings (OSTI)

Modeling concentrated solutions demands the use of ion-interaction models such as Pitzer equations, which involve a large number of operations. Implementation of these models in large reactive transport simulations significantly increases the computation ... Keywords: Concentrated solutions, Evaporation of seawater, Geochemical modeling, HMW model, Invariant points, Object-oriented programming, Pitzer, Reactive transport modeling

S. A. Bea; J. Carrera; C. Ayora; F. Batlle

2010-04-01T23:59:59.000Z

372

Reactive transport model for the ambient unsaturated hydrogeochemical system at Yucca mountain, Nevada  

Science Conference Proceedings (OSTI)

To assist a technical review of a potential application for a geologic repository, a reactive transport model is presented for the ambient hydrogeochemical system at Yucca Mountain (YM). The model simulates two-phase, nonisothermal, advective and diffusive ... Keywords: Yucca mountain, geochemistry, groundwater chemistry, groundwater flow and transport, hydrology, reactive transport model, unsaturated zone

Lauren Browning; William M. Murphy; Chandrika Manepally; Randall Fedors

2003-04-01T23:59:59.000Z

373

Reactive transport in aquatic ecosystems: Rapid model prototyping in the open source software R  

Science Conference Proceedings (OSTI)

The concentrations of many natural compounds are altered by chemical and biological transformations, and physical processes such as adsorption and transport. Their fate can be predicted using reactive transport models that describe reaction and advective ... Keywords: Model, Open source, R, Reactive transport, Software

Karline Soetaert; Filip Meysman

2012-06-01T23:59:59.000Z

374

Cost of Providing Ancillary Services from Power Plants: Reactive Supply and Voltage Control  

Science Conference Proceedings (OSTI)

This report provides a methodology for determining the variable costs of generating and supplying reactive power to a transmission system, via the generator step-up transformer, for system voltage control. The report examines the costs of additional energy losses, maintenance, repair, and plant aging associated with the generation of reactive power. TR-107270-V3SI contains System of International units.

1997-09-02T23:59:59.000Z

375

Multi-objective reactive power market clearing in competitive electricity market using HFMOEA  

Science Conference Proceedings (OSTI)

This paper presents an application of a hybrid fuzzy multi-objective evolutionary algorithm (HFMOEA) for solving a highly constraint, mixed integer type, complex multi-objective reactive power market clearing (RPMC) problem for the competitive electricity ... Keywords: Competitive electricity market, Fuzzy logic controller, Hybrid evolutionary algorithm, Multi-objective optimization, Pareto-optimal front, Reactive power market clearing

Ashish Saini; Amit Saraswat

2013-04-01T23:59:59.000Z

376

A transport based one-dimensional perturbation code for reactivity calculations in metal systems  

SciTech Connect

A one-dimensional reactivity calculation code is developed using first order perturbation theory. The reactivity equation is based on the multi-group transport equation using the discrete ordinates method for angular dependence. In addition to the first order perturbation approximations, the reactivity code uses only the isotropic scattering data, but cross section libraries with higher order scattering data can still be used with this code. The reactivity code obtains all the flux, cross section, and geometry data from the standard interface files created by ONEDANT, a discrete ordinates transport code. Comparisons between calculated and experimental reactivities were done with the central reactivity worth data for Lady Godiva, a bare uranium metal assembly. Good agreement is found for isotopes that do not violate the assumptions in the first order approximation. In general for cases where there are large discrepancies, the discretized cross section data is not accurately representing certain resonance regions that coincide with dominant flux groups in the Godiva assembly. Comparing reactivities calculated with first order perturbation theory and a straight {Delta}k/k calculation shows agreement within 10% indicating the perturbation of the calculated fluxes is small enough for first order perturbation theory to be applicable in the modeled system. Computation time comparisons between reactivities calculated with first order perturbation theory and straight {Delta}k/k calculations indicate considerable time can be saved performing a calculation with a perturbation code particularly as the complexity of the modeled problems increase.

Wenz, T.R.

1995-02-01T23:59:59.000Z

377

Benchmarking a Visual-Basic based multi-component one-dimensional reactive transport modeling tool  

Science Conference Proceedings (OSTI)

We present the details of a comprehensive numerical modeling tool, RT1D, which can be used for simulating biochemical and geochemical reactive transport problems. The code can be run within the standard Microsoft EXCEL Visual Basic platform, and it does ... Keywords: Bioremediation, Geochemical transport, Groundwater models, Numerical model, Reactive transport

Jagadish Torlapati; T. Prabhakar Clement

2013-01-01T23:59:59.000Z

378

Optimal Allocation of Reactive Power Source in Wind Farms Using Sensitivity Analysis and Tabu Algorithm  

Science Conference Proceedings (OSTI)

Considering wind farms real operation characteristics, a novel method using sensitivity analysis and Tabu algorithm for reactive power compensation allocations is proposed. In this paper, the sensitivity coefficient is defined as partial derivative of ... Keywords: Wind farm, Sensitivity analysis, Reactive power compensation, SVC, Tabu algorithm

Ping Zhang; XiangJun Zeng; Ling Li

2008-10-01T23:59:59.000Z

379

Reactive and Real-Time Systems Course: How to Get the Most Out of it  

Science Conference Proceedings (OSTI)

The paper describes the syllabus and the students’ projects from a graduate course on the subject of “Reactive and Real-Time Systems”, taught at Tel-Aviv University and at the Open University of Israel. The course focuses on the development ... Keywords: course syllabus, reactive real-time systems, scheduling, synchronous languages, verification

Tal Lev-Ami; Shmuel S. Tyszberowicz

2003-09-01T23:59:59.000Z

380

PEV-based Reactive Power Compensation for Wind DG Units: A Stackelberg Game Approach  

E-Print Network (OSTI)

turbine's inductive load to ensure a stable voltage profile in the system. Since reactive power can only from the load centers, DG units will speed up the revolution of providing power on site with little unit. Reactive power compensa- tion is needed since the load is not pure resistive and may include

Wu, Chenye

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Accelerating moderately stiff chemical kinetics in reactive-flow simulations using GPUs  

Science Conference Proceedings (OSTI)

The chemical kinetics ODEs arising from operator-split reactive-flow simulations were solved on GPUs using explicit integration algorithms. Nonstiff chemical kinetics of a hydrogen oxidation mechanism (9 species and 38 irreversible reactions) were computed ... Keywords: CUDA, Chemical kinetics, GPU, Reactive-flow modeling, Stiff chemistry

Kyle E. Niemeyer, Chih-Jen Sung

2014-01-01T23:59:59.000Z

382

Joint optimization algorithm for network reconfiguration and reactive power control of wind farm in distribution system  

Science Conference Proceedings (OSTI)

In recent years, the number of small size wind farms used as DG sources located within the distribution system are rapidly increasing. Wind farm made up with doubly fed induction generators (DFIG) is proposed in this paper as the continuous reactive ... Keywords: DFIG wind turbine, network reconfiguration, particle swarm optimization, reactive power control, wind farm

Jingjing Zhao; Xin Li; Jiping Lu; Congli Zhang

2009-02-01T23:59:59.000Z

383

Modeling of Hydrogen Storage Materials: A Reactive Force Field for NaH  

E-Print Network (OSTI)

is the fall in potential energy surface during heating. Keywords: hydrogen storage, reactive force fieldModeling of Hydrogen Storage Materials: A Reactive Force Field for NaH Ojwang' J.G.O.*, Rutger van governing hydrogen desorption in NaH. During the abstraction process of surface molecular hydrogen charge

Goddard III, William A.

384

Depletion Reactivity Benchmark for the International Handbook of Evaluated Reactor Physics Benchmark Experiments  

Science Conference Proceedings (OSTI)

The Electric Power Research Institute– (EPRI-) sponsored depletion reactivity benchmarks documented in reports 1022909, Benchmarks for Quantifying Fuel Reactivity Depletion Uncertainty, and 1025203, Utilization of the EPRI Depletion Benchmarks for Burnup Credit Validation, have been translated to an evaluated benchmark for incorporation in the International Handbook of Evaluated Reactor Physics Benchmark Experiments (IRPhE), published by the Organisation for Economic ...

2013-04-10T23:59:59.000Z

385

Optimal Planning of Reactive Power Compensators for Oil Field Distribution Networks  

Science Conference Proceedings (OSTI)

The characteristic behavior of the loads of oil pumps is analyzed. An approach for low-voltage side reactive power compensators of oil field distribution networks is put forward. Based on the supplied loads of transformers, the index of maximum reduction ... Keywords: Genetic Algorithm, distribution network, oil field, reactive power compensation

Wu Xiaomeng; Yan Suli

2009-05-01T23:59:59.000Z

386

Compatibility Analysis on Existing Reactivity Devices in CANDU 6 Reactors for DUPIC Fuel Cycle  

Science Conference Proceedings (OSTI)

The performance of reactivity devices for a Canada deuterium uranium (CANDU) 6 reactor loaded with Direct Use of Spent Pressurized Water Reactor Fuel In CANDU reactors (DUPIC) fuel is assessed. The reactivity devices studied are the zone controller units, the adjuster rods, and the mechanical control absorbers. For the zone controller system, the bulk reactivity control, spatial power control, and damping capability for spatial oscillation are investigated. For the adjusters, the xenon override, restart after a poison-out, shim operation, and power step-back capabilities are confirmed. The mechanical control absorber is assessed for the function of compensating temperature reactivity feedback following a power reduction. This study shows that the current reactivity device system of a CANDU 6 reactor is compatible with DUPIC fuel for normal and transient operations.

Jeong, Chang-Joon; Choi, Hangbok [Korea Atomic Energy Research Institute (Korea, Republic of)

2000-03-15T23:59:59.000Z

387

Reactivity studies of antitumor active dirhodium compounds with DNA oligonucleotides  

E-Print Network (OSTI)

The study of the mechanism of action of an antitumor active drug is essential for improving the efficacy and reducing the side effects of the drug as well as for developing better alternatives. In this vein, reactions of dirhodium compounds with DNA oligonucleotides were investigated by the techniques of mass spectrometry, HPLC, and NMR spectroscopic analytical methods. The relative reactivities of three dirhodium compounds, namely Rh2(O2CCH3)4, Rh2(O2CCF3)4, and [Rh2(O2CCH3)2(CH3CN)6](BF4)2, with DNA oligonucleotides were studied and compared to the clinically used anticancer drugs cisplatin and carboplatin using both MALDI and ESI mass spectrometric methods. The compound Rh2(O2CCF3)4 exhibits the highest reactivity among the dirhodium compounds, which is comparable to cisplatin, followed by [Rh2(O2CCH3)2(CH3CN)6](BF4)2, and finally Rh2(O2CCH3)4 which is the least reactive. Various dirhodium-oligonucleotide adducts were detected with both MALDI and ESI methods, which involve substitution of different numbers of the original ligands of the given dirhodium compound. ESI MS was found to be a sufficiently soft ionization method for detecting intact metal adducts, and CID MS-MS was useful for detecting weakly bound species such as axial adducts [M+Rh2(O2CCH3)4] and for comparing the relative bond strength between ligands in the metal adduct. A combination of anion exchange HPLC purification and enzymatic digestion studies of the adducts of Rh2(O2CCH3)4 with the 5'-CCTTCAACTCTC oligonucleotide revealed that Rh2(O2CCH3)4 binds to the center or to the ends of the oligonucleotide sequence by displacement of one or two acetate groups. Kinetic products of the type [M+Rh2(O2CCH3)3] obtained from the reaction of Rh2(O2CCH3)4 with 5'-CTCTCAACTTCC were separated by employing both reverse phase and anion exchange HPLC methods. The adduct that involves binding of the dirhodium unit to the exocyclic N4 atom of C5 and the N7 of A6 was found to be most stable whereas other adducts involving binding of C3 or C12 residues are clearly less stable. Reaction of cis-[Rh2(DAP)(O2CCH3)3(CH3OH)](O2CCH3) (DAP = 1,12- diazaperylene) with 5'-CTCTCAACTTCC produced a major adduct in which DAP group intercalates between 6A and 7A in the double stranded adduct with the rhodium atom that is not coordinated to the DAP group forming a covalent bond to the N7 atom of 6A which lends stability to the adduct.

Kang, Mijeong

2005-12-01T23:59:59.000Z

388

Local Dynamic Reactive Power for Correction of System Voltage Problems  

SciTech Connect

Distribution systems are experiencing outages due to a phenomenon known as local voltage collapse. Local voltage collapse is occurring in part because modern air conditioner compressor motors are much more susceptible to stalling during a voltage dip than older motors. These motors can stall in less than 3 cycles (.05s) when a fault, such as on the sub-transmission system, causes voltage to sag to 70 to 60%. The reasons for this susceptibility are discussed in the report. During the local voltage collapse, voltages are depressed for a period of perhaps one or two minutes. There is a concern that these local events are interacting together over larger areas and may present a challenge to system reliability. An effective method of preventing local voltage collapse is the use of voltage regulation from Distributed Energy Resources (DER) that can supply or absorb reactive power. DER, when properly controlled, can provide a rapid correction to voltage dips and prevent motor stall. This report discusses the phenomenon and causes of local voltage collapse as well as the control methodology we have developed to counter voltage sag. The problem is growing because of the use of low inertia, high efficiency air conditioner (A/C) compressor motors and because the use of electric A/C is growing in use and becoming a larger percentage of system load. A method for local dynamic voltage regulation is discussed which uses reactive power injection or absorption from local DER. This method is independent, rapid, and will not interfere with conventional utility system voltage control. The results of simulations of this method are provided. The method has also been tested at the ORNL s Distributed Energy Communications and Control (DECC) Laboratory using our research inverter and synchronous condenser. These systems at the DECC Lab are interconnected to an actual distribution system, the ORNL distribution system, which is fed from TVA s 161kV sub-transmission backbone. The test results are also provided and discussed. The simulations and testing show that local voltage control from DER can prevent local voltage collapse. The results also show that the control can be provided so quickly, within 0.5 seconds, that is does not interfere with conventional utility methods.

Kueck, John D [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Xu, Yan [ORNL; Li, Huijuan [University of Tennessee, Knoxville (UTK); Adhikari, Sarina [ORNL; Irminger, Philip [ORNL

2008-12-01T23:59:59.000Z

389

Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2-  

Open Energy Info (EERE)

Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2- Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2- and Water-Based Geothermal Reservoirs Geothermal Lab Call Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Advancing Reactive Tracer Methods for Measuring Thermal Evolution in CO2- and Water-Based Geothermal Reservoirs Project Type / Topic 1 Laboratory Call for Submission of Applications for Research, Development and Analysis of Geothermal Technologies Project Type / Topic 2 Tracers and Tracer Interpretation Project Description The concepts and theory behind the use of heat-sensitive tracers to study the thermal evolution of geothermal reservoirs was developed in the late 1980's under the Hot Dry Rock Project. Those studies described-conceptually and mathematically-the application of reactive tracers to tracking thermal fronts and to reservoir sizing. Later mathematical treatments focused on application of a single reactive tracer test to recover the temperature profile of a single streamtube. Previous tracer work has mainly focused on identifying conservative tracers. In these studies, chemicals that degraded at reservoir temperatures were discarded. Benzoic acids and dicarboxylic acids, which were found by Adams to degrade, may be useful as reactive tracers. Organic esters and amide tracers that undergo hydrolysis have been investigated and their use as reactive tracers appears feasible over a temperature range of 100ºC to 275ºC. However their reaction rates are pH dependent and sorption reactions have not been evaluated. While reactive tracer parameters have been measured in the lab, reactive tracers have not been extensively tested in the field. Thus, while reactive tracers appear to be a promising means of monitoring the thermal evolution of a geothermal reservoir, the concept has yet to be tested at the scale necessary for successful implementation, and tools for analyzing results of such tracer tests under the non-ideal conditions of an actual geothermal system have yet to be developed.

390

Slide 1  

NLE Websites -- All DOE Office Websites (Extended Search)

using XRD, ICP-MS - High-resolution micro computed tomography * Modeling - Multiphase reactive transport simulator - ARTS - Discrete-element model (DEM) for...

391

DOE/EA-1310: Environmental Assessment for Decontamination and Dismantlement of the Advanced Reactivity Measurement Facility and Couples Fast Reactivity Measurements Facility at the Idaho National Engineering and Environmental Laboratory  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

0 0 March 2000 Environmental Assessment for Decontamination and Dismantlement of the Advanced Reactivity Measurement Facility and Coupled Fast Reactivity Measurements Facility at the Idaho National Engineering and Environmental Laboratory DOE/EA-1310 Environmental Assessment for Decontamination and Dismantlement of the Advanced Reactivity Measurement Facility and Coupled Fast Reactivity Measurements Facility at the Idaho National Engineering and Environmental Laboratory Published March 2000 Prepared for the U.S. Department of Energy Idaho Operations Office iii CONTENTS ACRONYMS ............................................................................................................................... v HELPFUL INFORMATION ........................................................................................................

392

Installation of reactive metals groundwater collection and treatment systems  

SciTech Connect

Three groundwater plumes contaminated with volatile organic compounds (VOCs) and radionuclides at the Rocky Flats Environmental Technology Site are scheduled for remediation by 1999 based on the Rocky Flats Cleanup Agreement (RFCA) (DOE, 1996). These three plumes are among the top 20 environmental cleanup sites at Rocky Flats. One of these plumes, the Mound Site Plume, is derived from a previous drum storage area, and daylights as seeps near the South Walnut Creek drainage. Final design for remediation of the Mound Site Plume has been completed based on use of reactive metals to treat the contaminated groundwater, and construction is scheduled for early 1998. The two other plumes, the 903 Pad/Ryan`s Pit and the East Trenches Plumes, are derived from VOCs either from drums that leaked or that were disposed of in trenches. These two plumes are undergoing characterization and conceptual design in 1998 and construction is scheduled in 1999. The contaminants of concern in these plumes are tetrachloroethene, trichloroethene, carbon tetrachloride and low levels of uranium and americium.

Hopkins, J.K.; Primrose, A.L. [Rocky Mountain Remediation Services, LLC, Golden, CO (United States). Rocky Flats Environmental Technology Site; Vogan, J. [EnviroMetal Technologies, Inc., Guelph, Ontario (Canada); Uhland, J. [Kaiser-Hill, LLC, Golden, CO (United States). Rocky Flats Environmental Technology Site

1998-07-01T23:59:59.000Z

393

Reactive gas atomization processing for Fe-based ODS alloys  

SciTech Connect

Gas atomization reaction synthesis was employed as a simplified method for processing oxide dispersion forming precursor Fe-based powders (e.g., Fe–Cr–Y–Hf). During this process a reactive atomization gas (i.e., Ar–O2) was used to oxidize the powder surfaces during primary break-up and rapid solidification of the molten alloy. This resulted in envelopment of the powders by an ultra-thin (t < 50 nm) metastable Cr-enriched oxide shell that was used as a vehicle to transport oxygen into the consolidated microstructure. Subsequent elevated temperature heat treatment promoted thermodynamically driven oxygen exchange reactions between trapped films of Cr-enriched oxide and internal (Y, Hf)-enriched intermetallic precipitates, resulting in highly stable nano-metric mixed oxide dispersoids (i.e., Y–Hf–O) that were identified with X-ray diffraction. Transmission electron microscopy and atom probe tomography results also revealed that the size and distribution of the dispersoids were found to depend strongly on the original rapidly solidified microstructure. To exploit this, several oxide dispersion strengthened microstructures were engineered from different powder particle size ranges, illustrating microstructural control as a function of particle solidification rate. Additionally, preliminary thermal–mechanical processing was used to develop a fine scale dislocation substructure for ultimate strengthening of the alloy.

Rieken, Joel R [Ames Laboratory; Anderson, Iver E [Ames Laboratory; Kramer, Matthew J [Ames Laboratory; Odette, G R [University of California; Stergar, E [University of California; Haney, E [University of California

2011-08-24T23:59:59.000Z

394

Modern integral equation techniques for quantum reactive scattering theory  

SciTech Connect

Rigorous calculations of cross sections and rate constants for elementary gas phase chemical reactions are performed for comparison with experiment, to ensure that our picture of the chemical reaction is complete. We focus on the H/D+H{sub 2} {yields} H{sub 2}/DH + H reaction, and use the time independent integral equation technique in quantum reactive scattering theory. We examine the sensitivity of H+H{sub 2} state resolved integral cross sections {sigma}{sub v{prime}j{prime},vj}(E) for the transitions (v = 0,j = 0) to (v{prime} = 1,j{prime} = 1,3), to the difference between the Liu-Siegbahn-Truhlar-Horowitz (LSTH) and double many body expansion (DMBE) ab initio potential energy surfaces (PES). This sensitivity analysis is performed to determine the origin of a large discrepancy between experimental cross sections with sharply peaked energy dependence and theoretical ones with smooth energy dependence. We find that the LSTH and DMBE PESs give virtually identical cross sections, which lends credence to the theoretical energy dependence.

Auerbach, S.M.

1993-11-01T23:59:59.000Z

395

Three-dimensional visualization of reactive flows in complex geometries  

SciTech Connect

The visualization of fluid flows has become more challenging, as recent advancements in computational methods have increased the complexity and size of simulations. Our objective is to develop a flexible flow visualization tool for fluid simulations that include the full physics and geometrical complexities found in modeling practical combustion systems, such as internal combustion engines. The challenges to flow visualization come from: (1) the large simulation output, especially when using massively parallel computers; (2) the increasingly complex geometries that include moving surfaces such as pistons and valves; (3) the complex physical phenomena in realistic problems of fuel injection, combustion fronts, boundary flows, and large scale turbulence; and (4) the numerical complexity of indirect addressing of computational elements, variable mesh connectivity, distorted elements, and moving meshes. We have developed a visualization program that addresses these complexities. The program was developed as a post-processor to the KIVA family of codes for reactive flow simulations. Because of the complexity of the KIVA codes, the visualization program is very versatile and applicable to any code with meshes of arbitrary hexahedrons. No comparable commercial visualization package could be found. To visualize the fluid flow, we use mass-less tracer particles that follow the movement of the fluid as determined from output files from the simulation. The movement of the tracer particles is based on a second-order spatial and temporal interpolation of the fluid velocities from successive simulation output files. The visualization program runs on a Silicon Graphics IRIS GTX workstation.

Fairfield, M.S.

1995-02-01T23:59:59.000Z

396

Etching radical controlled gas chopped deep reactive ion etching  

DOE Patents (OSTI)

A method for silicon micromachining techniques based on high aspect ratio reactive ion etching with gas chopping has been developed capable of producing essentially scallop-free, smooth, sidewall surfaces. The method uses precisely controlled, alternated (or chopped) gas flow of the etching and deposition gas precursors to produce a controllable sidewall passivation capable of high anisotropy. The dynamic control of sidewall passivation is achieved by carefully controlling fluorine radical presence with moderator gasses, such as CH.sub.4 and controlling the passivation rate and stoichiometry using a CF.sub.2 source. In this manner, sidewall polymer deposition thicknesses are very well controlled, reducing sidewall ripples to very small levels. By combining inductively coupled plasmas with controlled fluorocarbon chemistry, good control of vertical structures with very low sidewall roughness may be produced. Results show silicon features with an aspect ratio of 20:1 for 10 nm features with applicability to nano-applications in the sub-50 nm regime. By comparison, previous traditional gas chopping techniques have produced rippled or scalloped sidewalls in a range of 50 to 100 nm roughness.

Olynick, Deidre; Rangelow, Ivo; Chao, Weilun

2013-10-01T23:59:59.000Z

397

Apparatus for continuously referenced analysis of reactive components in solution  

DOE Patents (OSTI)

A continuously referenced apparatus for measuring the concentration of a reactive chemical species in solution comprises in combination conduit means for introducing a sample solution, means for introducing one or more reactants into a sample solution, a reaction zone in fluid communication with said conduit means wherein a first chemical reaction occurs between said species and reactants, and a stream separator disposed within the conduit means for separating the sample solution into a sample stream and a reference stream. An enzymatic reactor is disposed in fluid communication with only the sample stream wherein a second reaction takes place between the said reactants, species, and reactor enzymes causing the consumption or production of an indicator species in just the sample stream. Measurement means such as a photometric system are disposed in communication with the sample and reference streams, and the outputs of the measurement means are compared to provide a blanked measurement of the concentration of indicator species. A peristaltic pump is provided to equalize flow through the apparatus by evacuation. The apparatus is particularly suitable for measurement of isoenzymes in body tissues or fluids.

Bostick, William D. (Oak Ridge, TN); Denton, Mark S. (Oak Ridge, TN); Dinsmore, Stanley R. (Norris, TN)

1981-01-01T23:59:59.000Z

398

Predictive modeling of reactive wetting and metal joining.  

SciTech Connect

The performance, reproducibility and reliability of metal joints are complex functions of the detailed history of physical processes involved in their creation. Prediction and control of these processes constitutes an intrinsically challenging multi-physics problem involving heating and melting a metal alloy and reactive wetting. Understanding this process requires coupling strong molecularscale chemistry at the interface with microscopic (diffusion) and macroscopic mass transport (flow) inside the liquid followed by subsequent cooling and solidification of the new metal mixture. The final joint displays compositional heterogeneity and its resulting microstructure largely determines the success or failure of the entire component. At present there exists no computational tool at Sandia that can predict the formation and success of a braze joint, as current capabilities lack the ability to capture surface/interface reactions and their effect on interface properties. This situation precludes us from implementing a proactive strategy to deal with joining problems. Here, we describe what is needed to arrive at a predictive modeling and simulation capability for multicomponent metals with complicated phase diagrams for melting and solidification, incorporating dissolutive and composition-dependent wetting.

van Swol, Frank B.

2013-09-01T23:59:59.000Z

399

Spectroscopy, Thermochemistry, and Reactivity of Lanthanide and Actinide Molecules  

SciTech Connect

The research undertaken under this grant is described in this document. The document describes progress in the construction of an instrument for recording photodissociation action spectra of mass-selected cryo-cooled cations. The instrument is not yet functional, but we anticipate trapping ions and conducting photodissociation experiments before the end of the year. It also describes resonant two-photon ionization spectra that have been recorded for uranium mononitride (UN) in the visible portion of the spectrum. These experiments are still underway at the present time. Although the spectra are a bit difficult to properly fit, due to upper state perturbations, it appears that the molecule has a ground state with {Omega} = 3.5 and a bond length of approximately 1.76 {angstrom}. Finally, results on the thermochemistry and reactivity of Th{sup +} are presented. In these studies the bond energies of the following bonds have been determined: D{sub 0}(Th{sup +}-2O) = 10.2 {+-} 0.2 eV; D0(Th{sup +}-N) = 6.69 {+-} 0.35 eV; D0(Th{sup +}-O) = 8.40 {+-} 0.28 eV; D{sub 0}(OTh{sup +}-O) = 1.8 {+-} 0.4 eV.

Morse, Michael D.; Armentrout, Peter B.

2012-08-16T23:59:59.000Z

400

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

Energy.gov (U.S. Department of Energy (DOE))

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

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Demonstration of the reactivity constraint approach on SNL's annual core research reactor  

Science Conference Proceedings (OSTI)

This paper reports on the initial demonstration of the reactivity constraint approach and its implementing algorithm, the MIT-CSDL Non-Linear Digital Controller, on the annual core research reactor (ACCR) that is operated by the Sandia National Laboratories. This demonstration constituted the first use of reactivity constraints for the closed-loop, digital control of reactor power on a facility other than the Massachusetts Institute of Technology's (MIT's) research reactor (MITR-II). Also, because the ACRR and the MITR-II are of very different design, these trials established the generic nature of the reactivity constraint approach.

Bernard, J.A.; Kwok, K.S.; Wyant, F.J.; Thome, F.V.

1989-01-01T23:59:59.000Z

402

The Safe Storage Study for Autocatalytic Reactive Chemicals  

E-Print Network (OSTI)

In the U.S. Chemical Safety and Hazard Investigation Board (CSB) report, Improving Reactive Hazard Management, there are 37 out of 167 accidents, which occurred in a storage tank or a storage area. This fact demonstrates that thermal runaway problems in chemical storage processes have not been give enough attention. Hydroxylamine Nitrate (HAN) is an important member of the hydroxylamine compound family and its diluted aqueous solution is widely used in the nuclear industry for equipment decontamination. It is also used as a solid or aqueous propellant. Due to its instability and autocatalytic behavior, it has been involved in several incidents at the Hanford and Savannah River Sites (SRS). Much research has been conducted on HAN in different areas, such as combustion mechanism, decomposition mechanism, and runaway behavior. However, the autocatalytic behavior of HAN at runaway stage has not been fully addressed due to its highly exothermic and rapid decomposition behavior. This work focuses on extracting its autocatalytic kinetics mechanism and studying its critical behavior from adiabatic calorimetry measurements. The lumped autocatalytic kinetics model, the associated model parameters and HAN critical condition are determined for the first time. The contamination effect of iron ions and nitric acid on diluted hydroxylamine nitrate solution is also studied. This work also identified the safe storage conditions for a small quantity HAN diluted solution with thermal explosion theory. Computational Fluid Dynamics (CFD) was used to further study the influence of natural convection and system scale on the critical behavior for a large quantity of chemical and thus proposed the practical storage guidelines for industrial practice.

Liu, Lijun

2009-08-01T23:59:59.000Z

403

Impact of C-reactive protein (CRP) on surfactant function  

Science Conference Proceedings (OSTI)

Plasma levels of the acute-phase reactant, C-reactive protein (CRP), increase up to one thousand-fold as a result of trauma or inflammation. CRP binds to phosphorylcholine (PC) in a calcium-ion dependent manner. The structural homology between PC and the major phospholipid component of surfactant, dipalmitoyl phosphatidylcholine (DPPC), led to the present study in which we examined if CRP levels might be increased in patients with adult respiratory distress syndrome (ARDS), and subsequently interfere with surfactant function. Our results showed that CRP levels in the bronchoalveolar fluid (BALF) was increased in patients with ARDS (97.8 +/- 84.2 micrograms/mg total protein vs. 4.04 +/- 2.2 micrograms/mg total protein in normals). Our results show that CRP binds to liposomes containing DPPC and phosphatidylglycerol (PG). As a result of this interaction, CRP inhibits the surface activity of a PG-DPPC mixture when tested with a Wilhelmy surfactometer or with the Enhorning pulsating bubble apparatus. Furthermore, the surface activity of a clinically used surfactant replacement, Surfactant TA (2 mg/ml), was also severely impaired by CRP in a dose-dependent manner (doses used ranging from 24.5 to 1,175 micrograms/ml). In contrast, human serum albumin (HSA) at 500 and 900 micrograms/ml had no inhibitory effect on Surfactant TA surface activity. These results suggest that CRP, although not an initiating insult in ARDS, may contribute to the subsequent abnormalities of surfactant function and thus the pathogenesis of the pulmonary dysfunction seen in ARDS.

Li, J.J.; Sanders, R.L.; McAdam, K.P.; Hales, C.A.; Thompson, B.T.; Gelfand, J.A.; Burke, J.F. (Shriners Burns Institute, Boston, MA (USA))

1989-12-01T23:59:59.000Z

404

Combining thorium with burnable poison for reactivity control of a very long cycle BWR  

E-Print Network (OSTI)

The effect of utilizing thorium together with gadolinium, erbium, or boron burnable absorber in BWR fuel assemblies for very long cycle is investigated. Nuclear characteristics such as reactivity and power distributions ...

Inoue, Yuichiro, 1969-

2004-01-01T23:59:59.000Z

405

Distributed control of reactive power flow in a radial distribution circuit with high photovoltaic penetration  

E-Print Network (OSTI)

We show how distributed control of reactive power can serve to regulate voltage and minimize resistive losses in a distribution circuit that includes a significant level of photovoltaic (PV) generation. To demonstrate the technique, we consider a radial distribution circuit with a single branch consisting of sequentially-arranged residential-scale loads that consume both real and reactive power. In parallel, some loads also have PV generation capability. We postulate that the inverters associated with each PV system are also capable of limited reactive power generation or consumption, and we seek to find the optimal dispatch of each inverter's reactive power to both maintain the voltage within an acceptable range and minimize the resistive losses over the entire circuit. We assume the complex impedance of the distribution circuit links and the instantaneous load and PV generation at each load are known. We compare the results of the optimal dispatch with a suboptimal local scheme that does not require any com...

Turitsyn, Konstantin; Backhaus, Scott; Chertkov, Michael

2009-01-01T23:59:59.000Z

406

Investigation on Durability and Reactivity of Promising Metal Oxide Sorbents During Sulfidation and Regeneration  

SciTech Connect

Research activities and efforts of this research project were concentrated on formulating various metal oxide sorbents with various additives under various formulation conditions, conducting experiments on initial reactivity of formulated sorbents with hydrogen sulfide, and testing hardness of formulated sorbents. Experiments on reactivity of formulated metal oxide sorbents with wet hydrogen sulfide contained in a simulated coal gas mixture were carried out for 120 seconds at 550 o C (see Table 1) to evaluate reactivity of formulated sorbents with hydrogen sulfide. Hardness of formulated sorbents was evaluated in addition to testing their reactivity with hydrogen sulfide. A typical simulated coal gas mixture consists of 9107-ppm hydrogen sulfide (0.005 g; 1 wt %), 0.085-g water (15.84 wt %), 0.0029-g hydrogen (0.58 wt %), and 0.4046-g nitrogen (81.34 wt%).

K. C. Kwon

1997-05-01T23:59:59.000Z

407

Phototriggered production of reactive oxygen species by TIO2 nanospheres and rods  

Science Conference Proceedings (OSTI)

We present the study of reactive oxygen species production under the light irradiation of two different types of TiO2 nanocrystals. Both TiO2 spheric NPs and anisotropic nanorods were investigated using activation of the horseradish ...

Bianca Geiseler, Marko Miljevic, Philipp Müller, Ljiljana Fruk

2012-01-01T23:59:59.000Z

408

Reactivity of Ti2AlC with SiC Fibers and Powders up to ...  

Science Conference Proceedings (OSTI)

Herein we investigated the reactivity of Ti2AlC [3ONE2] with SiC fibers [Avco Specialty Materials and Nippon Carbon Co.] and fine SiC powders [Superior ...

409

Mild coal pretreatment to improve liquefaction reactivity. Quarterly technical progress report, June--August 1991  

SciTech Connect

This report describes work completed during the fourth quarter of a three year project to study the effects of mild chemical pretreatment on coal dissolution reactivity during low severity liquefaction or coal/oil coprocessing. The overall objective of this research is to elucidate changes in the chemical and physical structure of coal by pretreating with methanol or other simple organic solvent and a trace amount of hydrochloric acid and measure the influence of these changes on coal dissolution reactivity. This work is part of a larger effort to develop a new coal liquefaction or coal/oil coprocessing scheme consisting of three main process steps: (1) mile pretreatment of the feed coal to enhance dissolution reactivity and dry the coal, (2) low severity thermal dissolution of the pretreated coal to obtain a very reactive coal-derived residual material amenable to upgrading, and (3) catalytic upgrading of the residual products to distillate liquids.

Miller, R.L.

1991-12-31T23:59:59.000Z

410

Integration of reactive polymeric nanofilms into a low-power electromechanical switch for selective chemical sensing  

E-Print Network (OSTI)

This paper presents the fabrication and demonstration of an ultrathin microelectromechanical chemical sensing device. Microcantilevers are etched from 100-nm-thick silicon nitride, and a 75-nm-thick reactive copolymer film ...

Arora, William J.

411

Numerical Modeling of the Turbulent Fluxes of Chemically Reactive Trace Gases in the Atmospheric Boundary Layer  

Science Conference Proceedings (OSTI)

Turbulent fluxes of chemically reactive trace gases in the neutral atmospheric boundary layer (ABL) were simulated with a one-dimensional, coupled diffusion-chemistry model. The effects of rapid chemical reactions were included with a suite of ...

W. Gao; M. L. Wesely

1994-07-01T23:59:59.000Z

412

Analysis of Reactivity Induced Accident for Control Rods Ejection with Loss of Cooling  

E-Print Network (OSTI)

Understanding of the time-dependent behavior of the neutron population in nuclear reactor in response to either a planned or unplanned change in the reactor conditions, is a great importance to the safe and reliable operation of the reactor. In the present work, the point kinetics equations are solved numerically using stiffness confinement method (SCM). The solution is applied to the kinetics equations in the presence of different types of reactivities and is compared with different analytical solutions. This method is also used to analyze reactivity induced accidents in two reactors. The first reactor is fueled by uranium and the second is fueled by plutonium. This analysis presents the effect of negative temperature feedback with the addition positive reactivity of control rods to overcome the occurrence of control rod ejection accident and damaging of the reactor. Both power and temperature pulse following the reactivity- initiated accidents are calculated. The results are compared with previous works and...

Saad, Hend Mohammed El Sayed; Wahab, Moustafa Aziz Abd El

2013-01-01T23:59:59.000Z

413

Molten Salt Multi-anode Reactive Alloy Coating(MARC) of Ta-W ...  

Science Conference Proceedings (OSTI)

In this study, Ta-W coated samples (Ta-7.31W, Ta-4.12W and Ta-1.92W) were prepared by multi-anode reactive alloy coating (MARC) process in molten salt ...

414

Assessment of the Economic Potential of Microgrids for Reactive Power Supply  

DOE Green Energy (OSTI)

As power generation from variable distributed energy resources (DER) grows, energy flows in the network are changing, increasing the requirements for ancillary services, including voltage support. With the appropriate power converter, DER can provide ancillary services such as frequency control and voltage support. This paper outlines the economic potential of DERs coordinated in a microgrid to provide reactive power and voltage support at its point of common coupling. The DER Customer Adoption Model assesses the costs of providing reactive power, given local utility rules. Depending on the installed DER, the cost minimizing solution for supplying reactive power locally is chosen. Costs include the variable cost of the additional losses and the investment cost of appropriately over-sizing converters or purchasing capacitors. A case study of a large health care building in San Francisco is used to evaluate different revenue possibilities of creating an incentive for microgrids to provide reactive power.

Appen, Jan von; Marnay, Chris; Stadler, Michael; Momber, Ilan; Klapp, David; Scheven, Alexander von

2011-05-01T23:59:59.000Z

415

Numerical Simulation of the Transport of Chemically Reactive Species under Land- and Sea-Breeze Circulations  

Science Conference Proceedings (OSTI)

The characteristics of the transport of chemically reactive species under land- and sea-breeze (LSB) circulations are investigated using a detailed transport/chemistry model, which includes 84 gas-phase and 10 heterogeneous chemical reactions. ...

Toshihiro Kitada; Gregory R. Carmichael; Leonard K. Peters

1984-08-01T23:59:59.000Z

416

Analysis of Reactivity Induced Accident for Control Rods Ejection with Loss of Cooling  

E-Print Network (OSTI)

Understanding of the time-dependent behavior of the neutron population in nuclear reactor in response to either a planned or unplanned change in the reactor conditions, is a great importance to the safe and reliable operation of the reactor. In the present work, the point kinetics equations are solved numerically using stiffness confinement method (SCM). The solution is applied to the kinetics equations in the presence of different types of reactivities and is compared with different analytical solutions. This method is also used to analyze reactivity induced accidents in two reactors. The first reactor is fueled by uranium and the second is fueled by plutonium. This analysis presents the effect of negative temperature feedback with the addition positive reactivity of control rods to overcome the occurrence of control rod ejection accident and damaging of the reactor. Both power and temperature pulse following the reactivity- initiated accidents are calculated. The results are compared with previous works and satisfactory agreement is found.

Hend Mohammed El Sayed Saad; Hesham Mohammed Mohammed Mansour; Moustafa Aziz Abd El Wahab

2013-06-05T23:59:59.000Z

417

Identification of Critical Voltage Control Areas and Determination of Required Reactive Power Reserves  

Science Conference Proceedings (OSTI)

The objective of this research project is to investigate and devise a methodology for identifying areas in power systems that are prone to voltage instability under particular operating conditions and contingencies. These areas, which are prone to instability due to their lack of reactive power reserves, are referred to as critical voltage control areas (VCAs). Once VCAs are identified, methods of determining their adequate reactive power reserve requirements to ensure secure system operation under all c...

2008-12-09T23:59:59.000Z

418

Study on Reactive Power and Voltage Control of Power Grid with Small Hydropower  

Science Conference Proceedings (OSTI)

When it is in the wet season and the load is low, reactive power surplus and voltage rise are caused by high-efficiency power generation of small hydropower and load reduction in Linjiang region, Baishan city, JiLin province. These problems, which exist ... Keywords: small hydro power, vally load, reactive power balance, the rise in voltage, generator in leading power factor on operation

Yaopeng Bai; Lijie Xu; Wei Wang

2010-06-01T23:59:59.000Z

419

Numerical Simulation of Injectivity Effects of Mineral Scaling and Clay Swelling in a Fractured Geothermal Reservoir  

DOE Green Energy (OSTI)

A major concern in the development of hot dry rock (HDR) and hot fractured rock (HFR) reservoirs is achieving and maintaining adequate injectivity, while avoiding the development of preferential short-circuiting flow paths such as those caused by thermally-induced stress cracking. Past analyses of HDR and HFR reservoirs have tended to focus primarily on the coupling between hydrology (flow), heat transfer, and rock mechanics. Recent studies suggest that rock-fluid interactions and associated mineral dissolution and precipitation effects could have a major impact on the long-term performance of HFR reservoirs. The present paper uses recent European studies as a starting point to explore chemically-induced effects of fluid circulation in HFR systems. We examine ways in which the chemical composition of reinjected waters can be modified to improve reservoir performance by maintaining or even enhancing injectivity. Chemical manipulations considered here include pH modification and dilution with fresh water. We performed coupled thermo-hydrologic-chemical simulations in which the fractured medium was represented by a one-dimensional MINC model (multiple interacting continua), using the non-isothermal multi-phase reactive geochemical transport code TOUGHREACT. Results indicate that modifying the injection water chemistry can enhance mineral dissolution and reduce clay swelling. Chemical interactions between rocks and fluids will change a HFR reservoir over time, with some changes favorable and others not. A detailed, quantitative understanding of processes and mechanisms can suggest chemical methods for reservoir management, which may be employed to improve the performance of the geothermal system.

Xu, Tianfu; Pruess, Karsten

2004-05-10T23:59:59.000Z

420

Development of an Enhanced GenVARR™ (Generator Volt Ampere Reactive Reserve) System  

SciTech Connect

Transmission system operators require near real time knowledge of reactive power capability to reliably operate large electric power transmission systems. Reactive power produced by, or capable of being produced by, a power generator is often estimated based on a series of mega volt amperes (MVA) capability curves for the generator. These curves indicate the ability of the generator to produce real and reactive power under a variety of conditions. In transmission planning and operating studies, it is often assumed, based on estimates for these capability curves, that the generator can provide its rated MVA capability output when needed for system stability However, generators may not always operate at levels depicted by the maximum MVA capability curve due to present constraints. Transmission system operators utilizing the generators’ capability curves for operation decisions regarding transmission system stability or for planning horizons may overestimate the capability of the generators to supply reactive power when required. Southern Company has enhanced GenVARR(TM), the system of plant data query, retrieval, and analysis and calculates the actual – not estimated -- remaining reactive power output capability. The remaining reactive output is considered spinning reserve and is displayed graphically to transmission control center and generating plant operators to identify real time VAR limits. GenVARR is capable of aggregating generators from a defined region, or other user selectable combinations, to represent the available reserves that the operators are specifically interested in. GenVARR(TM) has been put into live production operation and is expected to significantly improve the overall visibility of the reactive reserve capability of the system. This new version of GenVARR(TM) significantly enhances the products structure and performance, and enables links to other key transmission system operation tools.

Schatz, Joe E.

2009-03-12T23:59:59.000Z

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Application of Newton's optimal power flow in voltage/reactive power control  

Science Conference Proceedings (OSTI)

This paper considers an application of Newton's optimal power flow to the solution of the secondary voltage/reactive power control in transmission networks. An efficient computer program based on the latest achievements in the sparse matrix/vector techniques has been developed for this purpose. It is characterized by good robustness, accuracy and speed. A combined objective function appropriate for various system load levels with suitable constraints, for treatment of the power system security and economy is also proposed. For the real-time voltage/reactive power control, a suboptimal power flow procedure has been derived by using the reduced set of control variables. This procedure is based on the sensitivity theory applied to the determination of zones for the secondary voltage/reactive power control and corresponding reduced set of regulating sources, whose reactive outputs represent control variables in the optimal power flow program. As a result, the optimal power flow program output becomes a schedule to be used by operators in the process of the real-time voltage/reactive power control in both normal and emergency operating states.

Bjelogrlic, M.; Babic, B.S. (Electric Power Board of Serbia, Belgrade (YU)); Calovic, M.S. (Dept. of Electrical Engineering, University of Belgrade, Belgrade (YU)); Ristanovic, P. (Institute Nikola Tesla, Belgrade (YU))

1990-11-01T23:59:59.000Z

422

Reactive power interconnection requirements for PV and wind plants : recommendations to NERC.  

DOE Green Energy (OSTI)

Voltage on the North American bulk system is normally regulated by synchronous generators, which typically are provided with voltage schedules by transmission system operators. In the past, variable generation plants were considered very small relative to conventional generating units, and were characteristically either induction generator (wind) or line-commutated inverters (photovoltaic) that have no inherent voltage regulation capability. However, the growing level of penetration of non-traditional renewable generation - especially wind and solar - has led to the need for renewable generation to contribute more significantly to power system voltage control and reactive power capacity. Modern wind-turbine generators, and increasingly PV inverters as well, have considerable dynamic reactive power capability, which can be further enhanced with other reactive support equipment at the plant level to meet interconnection requirements. This report contains a set of recommendations to the North-America Electricity Reliability Corporation (NERC) as part of Task 1-3 (interconnection requirements) of the Integration of Variable Generation Task Force (IVGTF) work plan. The report discusses reactive capability of different generator technologies, reviews existing reactive power standards, and provides specific recommendations to improve existing interconnection standards.

McDowell, Jason (General Electric, Schenectady, NY); Walling, Reigh (General Electric, Schenectady, NY); Peter, William (SunPower, Richmond, CA); Von Engeln, Edi (NV Energy, Reno, NV); Seymour, Eric (AEI, Fort Collins, CO); Nelson, Robert (Siemens Wind Turbines, Orlando, FL); Casey, Leo (Satcon, Boston, MA); Ellis, Abraham; Barker, Chris. (SunPower, Richmond, CA)

2012-02-01T23:59:59.000Z

423

Energy Storage and Reactive Power Compensator in a Large Wind Farm: Preprint  

Science Conference Proceedings (OSTI)

The size of wind farm power systems is increasing, and so is the number of wind farms contributing to the power systems network. The size of wind turbines is also increasing--from less than 1 MW a few years ago to the 2- to 3-MW machines being installed today and the 5-MW machines under development. The interaction of the wind farm, energy storage, reactive power compensation, and the power system network is being investigated. Because the loads and the wind farms' output fluctuate during the day, the use of energy storage and reactive power compensation is ideal for the power system network. Energy storage and reactive power compensation can minimize real/reactive power imbalances that can affect the surrounding power system. In this paper, we will show how the contribution of wind farms affects the power distribution network and how the power distribution network, energy storage, and reactive power compensation interact when the wind changes. We will also investigate the size of the components in relation to each other and to the power system.

Muljadi, E.; Butterfield, C. P.; Yinger, R.; Romanowitz, H.

2003-10-01T23:59:59.000Z

424

Zero Valent Iron: Impact of Anions Present during Synthesis on Subsequent Nanoparticle Reactivity  

SciTech Connect

Zero-valent iron particles are an effective remediation technology for groundwater contaminated with halogenated organic compounds. In particular, nano-scale zero-valent iron is a promising material for remediation due to its high specific surface area, which results in faster rate constants and more effective use of the iron. An aspect of iron nanoparticle reactivity that has not been explored is the impact of anions present during iron metal nanoparticle synthesis. Solutions containing chloride, phosphate, sulfate, and nitrate anions and ferric ions were used to generate iron oxide nanoparticles. The resulting materials were dialyzed to remove dissolved byproducts and then dried and reduced by hydrogen gas at high temperature. The reactivity of the resulting zero valent iron nanoparticles was quantified by monitoring the kinetics as well as products of carbon tetrachloride reduction, and significant differences in reactivity and chloroform yield were observed. The reactivity of nanoparticles prepared in the presence of sulfate and phosphate demonstrated the highest reactivity and chloroform yield. Furthermore, substantial variations in the solid-state products of oxidation (magnetite, iron sulfide, and goethite, among others) were also observed.

Moore, Kirsten; Forsberg, Brady; Baer, Donald R.; Arnold, William A.; Penn, R. Lee

2011-10-01T23:59:59.000Z

425

A Preliminary Analysis of the Economics of Using Distributed Energy as a Source of Reactive Power Supply  

DOE Green Energy (OSTI)

A major blackout affecting 50 million people in the Northeast United States, where insufficient reactive power supply was an issue, and an increased number of filings made to the Federal Energy Regulatory Commission by generators for reactive power has led to a closer look at reactive power supply and compensation. The Northeastern Massachusetts region is one such area where there is an insufficiency in reactive power compensation. Distributed energy due to its close proximity to loads seems to be a viable option for solving any present or future reactive power shortage problems. Industry experts believe that supplying reactive power from synchronized distributed energy sources can be 2 to 3 times more effective than providing reactive support in bulk from longer distances at the transmission or generation level. Several technology options are available to supply reactive power from distributed energy sources such as small generators, synchronous condensers, fuel cells or microturbines. In addition, simple payback analysis indicates that investments in DG to provide reactive power can be recouped in less than 5 years when capacity payments for providing reactive power are larger than $5,000/kVAR and the DG capital and installation costs are lower than $30/kVAR. However, the current institutional arrangements for reactive power compensation present a significant barrier to wider adoption of distributed energy as a source of reactive power. Furthermore, there is a significant difference between how generators and transmission owners/providers are compensated for reactive power supplied. The situation for distributed energy sources is even more difficult, as there are no arrangements to compensate independent DE owners interested in supplying reactive power to the grid other than those for very large IPPs. There are comparable functionality barriers as well, as these smaller devices do not have the control and communications requirements necessary for automatic operation in response to local or system operators. There are no known distributed energy asset owners currently receiving compensation for reactive power supply or capability. However, there are some cases where small generators on the generation and transmission side of electricity supply have been tested and have installed the capability to be dispatched for reactive power support. Several concerns need to be met for distributed energy to become widely integrated as a reactive power resource. The overall costs of retrofitting distributed energy devices to absorb or produce reactive power need to be reduced. There needs to be a mechanism in place for ISOs/RTOs to procure reactive power from the customer side of the meter where distributed energy resides. Novel compensation methods should be introduced to encourage the dispatch of dynamic resources close to areas with critical voltage issues. The next phase of this research will investigate in detail how different options of reactive power producing DE can compare both economically and functionally with shunt capacitor banks. Shunt capacitor banks, which are typically used for compensating reactive power consumption of loads on distribution systems, are very commonly used because they are very cost effective in terms of capital costs. However, capacitor banks can require extensive maintenance especially due to their exposure to lightning at the top of utility poles. Also, it can be problematic to find failed capacitor banks and their maintenance can be expensive, requiring crews and bucket trucks which often requires total replacement. Another shortcoming of capacitor banks is the fact that they usually have one size at a location (typically sized as 300, 600, 900 or 1200kVAr) and thus don't have variable range as do reactive power producing DE, and cannot respond to dynamic reactive power needs. Additional future work is to find a detailed methodology to identify the hidden benefit of DE for providing reactive power and the best way to allocate the benefit among customers, utilities, transmission companies or RTOs.

Li, Fangxing [ORNL; Kueck, John D [ORNL; Rizy, D Tom [ORNL; King, Thomas F [ORNL

2006-04-01T23:59:59.000Z

426

ORNL/CP-97155 Instantaneous Reactive Power and Power Factor of  

Office of Scientific and Technical Information (OSTI)

ORNL/CP-97155 ORNL/CP-97155 Instantaneous Reactive Power and Power Factor of Instantaneous Phasor s ' 4 . L;/, Oak Ridge National Laboratory* P f Senior Member &Eb "'ii Lf/ .. John S. Hsu 4- p d Post Office Box 2009, MS 8038 Oak Ridge, Tennessee 3783 1-8038 Key wordr: Instantaneous reactive power, Symmetrical property, Instantaiteous phasors, Phasors of one phase, n r e e phases. Abstract The unique property of instantaneous phasors is that at any instant the instantaneous three-phase currents and voltages can be represented by a set of balanced phasors. The instantaneous reactive power and the concept of instantaneous power factor can be clearly understood from the instantaneous phasors. This provides a theoretical foundation for power quality monitoring, diagnostics,

427

Porous desulfurization sorbent pellets containing a reactive metal oxide and an inert zirconium compound  

DOE Patents (OSTI)

Sorbent pellets for removing hydrogen sulfide from coal gas are prepared by combining a reactive oxide, in particular zinc oxide, with a zirconium compound such as an oxide, silicate, or aluminate of zirconium, and an inorganic binder and pelletizing and calcining the mixture. Alternately, the zinc oxide may be replaced by copper oxide or a combination of copper, molybdenum, and manganese oxides. The pellet components may be mixed in dry form, moistened to produce a paste, and converted to pellets by forming an aqueous slurry of the components and spray drying the slurry, or the reactive oxide may be formed on existing zirconium-containing catalyst-carrier pellets by infusing a solution of a salt of the active metal onto the existing pellets and firing at a high temperature to produce the oxide. Pellets made according to this invention show a high reactivity with hydrogen sulfide and durability such as to be useful over repeated cycles of sorption and regeneration.

Gardner, Todd H.; Gasper-Galvin, Lee D.

1996-12-01T23:59:59.000Z

428

Reactivity worth measurements at the IPEN/MB-01 nuclear reactor  

Science Conference Proceedings (OSTI)

Researches that aim to improve the performance of neutron transport codes and quality of nuclear cross section databases are very important to increase the accuracy of simulations and the quality of the analysis and prediction of phenomena in the nuclear field. In this context, relevant experimental data such as reactivity worth measurements are needed. The objective of this work was to perform a series of experiments of reactivity worth measurements, using a digital reactivity meter developed at IPEN. The experiments employed small metallic and ceramic samples inserted in the central region of the core of the experimental IPEN/MB-01 reactor. The theoretical analysis was performed by the MCNP-5 reactor physics code, developed and maintained by Los Alamos National Laboratory, and the ENDF/B-VII.0 nuclear data library.

Pinto, Leticia Negrao; Santos, Adimir dos [Nuclear Engineering Center, Nuclear and Energy Research Institute- IPEN/CNEN-SP (Brazil)

2013-05-06T23:59:59.000Z

429

Impact of exhaust gas recirculation (EGR) on the oxidative reactivity of diesel engine soot  

SciTech Connect

This paper expands the consideration of the factors affecting the nanostructure and oxidative reactivity of diesel soot to include the impact of exhaust gas recirculation (EGR). Past work showed that soot derived from oxygenated fuels such as biodiesel carries some surface oxygen functionality and thereby possesses higher reactivity than soot from conventional diesel fuel. In this work, results show that EGR exerts a strong influence on the physical properties of the soot which leads to enhanced oxidation rate. HRTEM images showed a dramatic difference between the burning modes of the soot generated under 0 and 20% EGR. The soot produced under 0% EGR strictly followed an external burning mode with no evidence of internal burning. In contrast, soot generated under 20% EGR exhibited dual burning modes: slow external burning and rapid internal burning. The results demonstrate clearly that highly reactive soot can be achieved by manipulating the physical properties of the soot via EGR. (author)

Al-Qurashi, Khalid; Boehman, Andre L. [The EMS Energy Institute, The Pennsylvania State University, 405 Academic Activities Bldg., University Park, PA 16802 (United States)

2008-12-15T23:59:59.000Z

430

A simple model for radial expansion reactivity in LMRs (liquid metal reactors)  

Science Conference Proceedings (OSTI)

Presented in this report is a simple analytical model developed for evaluating the radial expansion reactivity in small modular liquid metal reactors (LMRs). The present model is based on a non-leakage representation of the effective neutron multiplication factor. The resultant analytical expression for the radial expansion reactivity is simple and can be used directly in a system code for safety analyses. Applications of the present model to PRISM and SAFR resulted in a good agreement with the values reported by vendors. This agreement establishes that the large negative reactivity insertion resulting from LMR core radial expansion can be confirmed using a simple analytical approach, and thus is important in the current effort to evaluate the reactor inherent feedbacks for the PRISM and SAFR designs.

Cheng, H.S.; Van Tuyle, G.J.

1988-01-01T23:59:59.000Z

431

Reactive instabilities of lower hybrid-like waves in regions with parallel currents  

Science Conference Proceedings (OSTI)

The dispersion and reactive instabilities of obliquely propagating waves near the lower hybrid (LH) frequency are studied in plasma carrying a current parallel to the magnetic field. Possible applications of these instabilities include magnetic reconnection regions, where LH-like waves may accelerate and heat both ions and electrons. In plasmas with a bulk drift of electrons relative to the ions at speed v{sub d} along the magnetic field, the forward and backward propagating LH modes are shown to be replaced by four LH-like modes. Reactive instabilities are discovered here for a forward propagating mode with Re({omega}){approx_equal}k{sub ||}v{sub d}/2 and a backward propagating mode with Re({omega})cold plasma calculations and agree well, confirming that the discovered instabilities are reactive. In the cold plasma limit, the forward and backward propagating instabilities occur for v{sub d} below and above some thresholds, respectively.

Verdon, A. L.; Cairns, Iver H.; Melrose, D. B.; Robinson, P. A. [School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia)

2011-05-15T23:59:59.000Z

432

Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation’s Cañon City, Colorado, Uranium Mill  

Energy.gov (U.S. Department of Energy (DOE))

Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation’s Canon City, Colorado, Uranium Mill (April 2005)

433

Cold Reactive Collisions between Laser-Cooled Ions and Velocity-Selected Neutral Molecules  

Science Conference Proceedings (OSTI)

We report a new experimental method to study reactive ion-molecule collisions at very low temperatures. A source of laser-cooled ions in a linear Paul trap has been combined with a quadrupole-guide velocity selector to investigate the reaction of Ca{sup +} with CH{sub 3}F at collision energies E{sub coll}/k{sub B}{>=}1 K with single-particle sensitivity. The technique represents a general approach to study reactive collisions between ions and polar molecules over a wide temperature range down to the cold regime.

Willitsch, Stefan; Bell, Martin T.; Gingell, Alexander D.; Procter, Simon R.; Softley, Timothy P. [Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford OX1 3TA (United Kingdom)

2008-02-01T23:59:59.000Z

434

CASMO5/TSUNAMI-3D spent nuclear fuel reactivity uncertainty analysis  

Science Conference Proceedings (OSTI)

The CASMO5 lattice physics code is used in conjunction with the TSUNAMI-3D sequence in ORNL's SCALE 6 code system to estimate the uncertainties in hot-to-cold reactivity changes due to cross-section uncertainty for PWR assemblies at various burnup points. The goal of the analysis is to establish the multiplication factor uncertainty similarity between various fuel assemblies at different conditions in a quantifiable manner and to obtain a bound on the hot-to-cold reactivity uncertainty over the various assembly types and burnup attributed to fundamental cross-section data uncertainty. (authors)

Ferrer, R.; Rhodes, J. [Studsvik Scandpower, Inc., 504 Shoup Ave., Idaho Falls, ID 83402 (United States); Smith, K. [Dept. of Nuclear Science and Engineering, Massachusetts Inst. of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

2012-07-01T23:59:59.000Z

435

Reactivation or expansion of Hotel Baker Hydro plant. Feasibility assessment report  

SciTech Connect

The Hotel Baker Hydroelectric Power plant, built in 1928 at St. Charles, IL., has two generating units which until 1970 supplied the hotel with 100 kW output at 6 ft. head. The feasibility of reactivating, upgrading, or replacing these units to again supply power for the hotel was evaluated considering installation and operating costs, financing requirements, environmental impacts, and regulatory requirements. It was concluded that the reactivation project is marginally attractive only with full use of the power output by an expanded hotel and if electric utility rates increase at 8% per year. (LCL)

1979-03-01T23:59:59.000Z

436

EXPERIMENTAL AND THEORETICAL INVESTIGATION OF MULTIPHASE FLOW  

E-Print Network (OSTI)

. A laboratory flow apparatus was built to obtain data on water-air imbibition and oil-water drainage have also been analyzed. In the case of water-air imbibition, the thin fracture system showed a more with a 1mm spacer between the blocks, and a two- block system with no spacer. The blocks were sealed

437

Multiphase, Multistructure, and Multifunctionality of Interface ...  

Science Conference Proceedings (OSTI)

... Engineered Oxide Heterostructures for Energy Conversion and Harvest ... for self-powered structural health monitoring systems, intermediate temperature thin  ...

438

Multiphase oil transport at complex micro geometry  

E-Print Network (OSTI)

Dynamic sealing systems, such as mechanical face seals and piston rings in internal combustion engines are critical components of modern machines. These sealing systems present a unique challenge in controlling the lubricant ...

Li, Yong, Ph. D. Massachusetts Institute of Technology

2011-01-01T23:59:59.000Z

439

Multiphase Flow and Cavern Abandonment in Salt  

Science Conference Proceedings (OSTI)

This report will explore the hypothesis that an underground cavity in gassy salt will eventually be gas filled as is observed on a small scale in some naturally occurring salt inclusions. First, a summary is presented on what is known about gas occurrences, flow mechanisms, and cavern behavior after abandonment. Then, background information is synthesized into theory on how gas can fill a cavern and simultaneously displace cavern fluids into the surrounding salt. Lastly, two-phase (gas and brine) flow visualization experiments are presented that demonstrate some of the associated flow mechanisms and support the theory and hypothesis that a cavity in salt can become gas filled after plugging and abandonment

Ehgartner, Brian; Tidwell, Vince

2001-02-13T23:59:59.000Z

440

Multiphase Strengthened Nickel Base Superalloys Containing ...  

Science Conference Proceedings (OSTI)

treatment and aging techniques. Table II: Compositi ions of Alloys Investigated. Alloy. 1. 2. 3. 4. 5. Base. ' + HfC. Alloy 1. Y+Y'+. IN-100. MERL 76. Corn pos ition.

Note: This page contains sample records for the topic "non-isothermal multiphase reactive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Multiphase Turbulent Flow Ken Kiger -UMCP  

E-Print Network (OSTI)

of the dispersion: · Size & geometry · Volume fraction #12;Bubbly Pipe Flow ­ heat exchangers in power plants, A/C units Gas-Liquid Flow #12;Aeration: -produced by wave action - used as reactor in chemical processing delivery Liquid-Gas Flow http://www.mywindpowersystem.com/2009/07/wind-power-when-nature

Gruner, Daniel S.

442

Fission of a multiphase membrane tube  

E-Print Network (OSTI)

A common mechanism for intracellular transport is the use of controlled deformations of the membrane to create spherical or tubular buds. While the basic physical properties of homogeneous membranes are relatively well-known, the effects of inhomogeneities within membranes are very much an active field of study. Membrane domains enriched in certain lipids in particular are attracting much attention, and in this Letter we investigate the effect of such domains on the shape and fate of membrane tubes. Recent experiments have demonstrated that forced lipid phase separation can trigger tube fission, and we demonstrate how this can be understood purely from the difference in elastic constants between the domains. Moreover, the proposed model predicts timescales for fission that agree well with experimental findings.

Jean-Marc Allain; Cornelis Storm; Aurelien Roux; Martine Ben Amar; Jean-Francois Joanny

2004-04-19T23:59:59.000Z

443

Budding and Fission of a multiphase vesicle  

E-Print Network (OSTI)

We present a model of bi-phasic vesicle in the limit of large surface tension. In this regime, the vesicle is completely stretched and well described by two spherical caps with a fold which concentrates the membrane stress. The conservation laws and geometric constraints restrict the space of possible shapes to a pair of solutions labeled by a parameter $\\tau$ given by {\\it line tension/pressure}. For a given $\\tau$ value, the two solutions differ by the length of the interface between domains. For a critical value $\\tau\\_c$, the two vesicle shapes become identical and no solution exists above this critical value. This model sheds new light on two proposed mechanisms (osmotic shocks and molecule absorption) to explain the budding and the fission in recent experiments.

Jean-Marc Allain; Martine Ben Amar

2005-04-08T23:59:59.000Z

444

Magnetohydrodynamic Model Coupling Multiphase Flow in ...  

Science Conference Proceedings (OSTI)

Compact Filter Design for Gas Treatment Centers ... Gas-Solid Flow Applications for Powder Handling in Aluminum Smelters Processes ... Replacement of Damaged Electrical Insulators on Live Cross-Over Busbars inside a Tunnel: A ...

445

Melt-processed Multiphasic Ceramic Waste Forms  

Science Conference Proceedings (OSTI)

Symposium, Materials Issues in Nuclear Waste Management in the 21st Century ... Scanning electron microscopy (SEM) and energy dispersive spectrometry ...

446

Multiphase flow in fractured porous media  

Science Conference Proceedings (OSTI)

The major goal of this research project was to improve the understanding of the gas-oil two-phase flow in fractured porous media. In addition, miscible displacement was studied to evaluate its promise for enhanced recovery.

Firoozabadi, A.

1995-02-01T23:59:59.000Z

447

Multiphase Sequestration Geochemistry: Model for Mineral Carbonation  

SciTech Connect

Carbonation of formation minerals converts low viscosity supercritical CO2 injected into deep saline reservoirs for geologic sequestration into an immobile form. Until recently the scientific focus of mineralization reactions with reservoir rocks has been those that follow an aqueous-mediated dissolution/precipitation mechanism, driven by the sharp reduction in pH that occurs with CO2 partitioning into the aqueous phase. For sedimentary basin formations the kinetics of aqueous-mediated dissolution/precipitation reactions are sufficiently slow to make the role of mineralization trapping insignificant over a century period. For basaltic saline formations aqueous-phase mineralization progresses at a substantially higher rate, making the role of mineralization trapping significant, if not dominant, over a century period. The overlooked mineralization reactions for both sedimentary and basaltic saline formations, however, are those that occur in liquid or supercritical CO2 phase; where, dissolved water appears to play a catalyst role in the formation of carbonate minerals. A model is proposed in this paper that describes mineral carbonation over sequestration reservoir conditions ranging from dissolved CO2 in aqueous brine to dissolved water in supercritical CO2. The model theory is based on a review of recent experiments directed at understanding the role of water in mineral carbonation reactions of interest in geologic sequestration systems occurring under low water contents.

White, Mark D.; McGrail, B. Peter; Schaef, Herbert T.; Hu, Jian Z.; Hoyt, David W.; Felmy, Andrew R.; Rosso, Kevin M.; Wurstner, Signe K.

2011-04-01T23:59:59.000Z

448

Numerical Simulation of Macrosegregation with Multiphase Model ...  

Science Conference Proceedings (OSTI)

However, the non-orthogonal grids are flexible in treatment of the boundary fitness ... Smart Use of Density Functional Theory Calculations to Drive Newtonian ...

449

Behavioral design to model a reactive decision of an expert in geothermal wells  

Science Conference Proceedings (OSTI)

Software design based on agents represents a new perspective for computer science and more specifically, for Artificial Intelligence. It is a new theory that has innovated the analysis, design and implementation of system software. The design of agents ... Keywords: Artificial Intelligence, Autonomous action, Behavioral analysis, Cognitive models, Geothermal wells, Inverse problem, Multi-agent architecture, Reactive agents, Subjective domain, Temperature formation

Ana Lilia Laureano-Cruces; Gilberto Espinosa-Paredes

2005-04-01T23:59:59.000Z

450

doi:10.1155/2011/839682 Review Article Haptenation: Chemical Reactivity and Protein Binding  

E-Print Network (OSTI)

Copyright © 2011 Itai Chipinda et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Low molecular weight chemical (LMW) allergens are commonly referred to as haptens. Haptens must complex with proteins to be recognized by the immune system. The majority of occupationally related haptens are reactive, electrophilic chemicals, or are metabolized to reactive metabolites that form covalent bonds with nucleophilic centers on proteins. Nonelectrophilic protein binding may occur through disulfide exchange, coordinate covalent binding onto metal ions on metalloproteins or of metal allergens, themselves, to the major histocompatibility complex. Recent chemical reactivity kinetic studies suggest that the rate of protein binding is a major determinant of allergenic potency; however, electrophilic strength does not seem to predict the ability of a hapten to skew the response between Th1 and Th2. Modern proteomic mass spectrometry methods that allow detailed delineation of potential differences in protein binding sites may be valuable in predicting if a chemical will stimulate an immediate or delayed hypersensitivity. Chemical aspects related to both reactivity and protein-specific binding are discussed. 1.

Itai Chipinda; Justin M. Hettick; Paul D. Siegel

2011-01-01T23:59:59.000Z

451

Reactivity Controlled Compression Ignition (RCCI) Combustion on a Multi-Cylinder Light-Duty Diesel Engine  

Science Conference Proceedings (OSTI)

Reactivity controlled compression ignition is a low-temperature combustion technique that has been shown, both in computational fluid dynamics modeling and single-cylinder experiments, to obtain diesel-like efficiency or better with ultra-low nitrogen oxide and soot emissions, while operating primarily on gasoline-like fuels. This paper investigates reactivity controlled compression ignition operation on a four-cylinder light-duty diesel engine with production-viable hardware using conventional gasoline and diesel fuel. Experimental results are presented over a wide speed and load range using a systematic approach for achieving successful steady-state reactivity controlled compression ignition combustion. The results demonstrated diesel-like efficiency or better over the operating range explored with low engine-out nitrogen oxide and soot emissions. A peak brake thermal efficiency of 39.0% was demonstrated for 2600 r/min and 6.9 bar brake mean effective pressure with nitrogen oxide emissions reduced by an order of magnitude compared to conventional diesel combustion operation. Reactivity controlled compression ignition emissions and efficiency results are compared to conventional diesel combustion operation on the same engine.

Curran, Scott [ORNL; Hanson, Reed M [ORNL; Wagner, Robert M [ORNL

2012-01-01T23:59:59.000Z

452

Second-order splitting schemes for a class of reactive systems  

Science Conference Proceedings (OSTI)

We consider the numerical time integration of a class of reaction-transport systems that are described by a set of ordinary differential equations for primary variables. In the governing equations, the terms involved may require the knowledge of secondary ... Keywords: 65L05, 80A32, Continuously stirred tank reactor, Operator splitting, Reaction-transport systems, Reduced description of reactive flows

Zhuyin Ren; Stephen B. Pope

2008-09-01T23:59:59.000Z

453

ADVANCING REACTIVE TRACER METHODS FOR MONITORING THERMAL DRAWDOWN IN GEOTHERMAL ENHANCED GEOTHERMAL RESERVOIRS  

Science Conference Proceedings (OSTI)

Reactive tracers have long been considered a possible means of measuring thermal drawdown in a geothermal system, before significant cooling occurs at the extraction well. Here, we examine the sensitivity of the proposed method to evaluate reservoir cooling and demonstrate that while the sensitivity of the method as generally proposed is low, it may be practical under certain conditions.

Mitchell A. Plummer; Carl D. Palmer; Earl D. Mattson; George D. Redden; Laurence C. Hull

2010-10-01T23:59:59.000Z

454

Topical Report on Reactivity Initiated Accident: Bases for RIA Fuel and Core Coolability Criteria  

Science Conference Proceedings (OSTI)

Revised acceptance criteria have been developed for the response of light water reactor (LWR) fuel under reactivity initiated accidents (RIA). Development of these revisions is part of an industry effort to extend burnup levels beyond currently licensed limits. The revised criteria are proposed for use in licensing burnup extensions or new fuel designs.

2002-05-22T23:59:59.000Z

455

Distributed control of reactive power flow in a radial distribution circuit with high photovoltaic penetration  

SciTech Connect

We show how distributed control of reactive power can serve to regulate voltage and minimize resistive losses in a distribution circuit that includes a significant level of photovoltaic (PV) generation. To demonstrate the technique, we consider a radial distribution circuit with a single branch consisting of sequentially-arranged residential-scale loads that consume both real and reactive power. In parallel, some loads also have PV generation capability. We postulate that the inverters associated with eac