| Soil Exchangeable Phosphorus Pools, Equilibrium Characteristics, and Mass Distribution Coefficients for Eight-Mile Run Watershed, Wisconsin |
Sep-2009 |
15 pages |
| Authors:
Zhonglong Zhang; Charles W Downer; Billy E Johnson; William F James; Aaron R Byrd; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS ENVIRONMENTAL LAB
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 | This research experimentally determined phosphorus mass distribution coefficients (i.e., relationship between soil exchangeable and soluble phosphorus), exchangeable phosphorus pools, and soluble phosphorus in the interstitial water for soils exhibiting a range of phosphorus concentrations. The research also developed relationships between these variables and commonly measured, crop-available soil phosphorus for use in establishing initial soil P parameters in the System-Wide Water Resources Program-Nutrient Sub-Model (SWWRP-NSM). |
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| Sediment Equilibrium and Diffusive Fluxes in Relation to Phosphorus Dynamics in the Turbid Minnesota River |
Jan-2009 |
36 pages |
| Authors:
William F James; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
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| Much is known regarding the importance of surface and subsurface runoff from agricultural watersheds in the regulation of soluble phosphorus (P) concentration in large river systems. However, in-stream processes such as equilibrium P flux from suspended sediment and diffusive P flux from deposited sediment stored in river channels may also play a role in soluble P control. Ranges in equilibrium partitioning between aqueous and exchangeable particulate P pools associated with ... |
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| Pylon Effects on a Scramjet Cavity Flameholder Flowfield |
01-Sep-2008 |
204 pages |
| Authors:
Andrew B Freeborn; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| Cavity flameholders in supersonic combustion ramjet (scramjet) combustors, while effective, fail to take advantage of the full combustor volume. Adding a pylon to the leading edge of a cavity flameholder generates a flowfield increasing mass exchange between the cavity and main combustor flow, increasing the mixing interface between flameholder products and main combustor flow, and exhibiting minimal Reynolds number effects. To demonstrate this modified flowfield driven by supersonic expansion behind ... |
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| Synthetic Spectrum Constraints on a Model of the Cataclysmic Variable QU Carinae |
Jan-2008 |
15 pages |
| Authors:
Paula Szkody; Patrick Godon; Albert P Linnell; Ivan Hubeny; Edward M Sion; Paul E Barrett; WASHINGTON UNIV SEATTLE DEPT OF ASTRONOMY
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| Neither standard model SEDs nor truncated standard model SEDs fit observed spectra of QU Carinae with acceptable accuracy over the range 900-3000 angstroms. Nonstandard model SEDs fit the observation set accurately. The nonstandard accretion disk models have a hot region extending from the white dwarf to R = 1:36R(sub WD), a narrow intermediate-temperature annulus, and an isothermal remainder to the tidal cutoff boundary. The models include a range of values ... |
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| Continued Investigation of Small-Scale Air-Sea Coupled Dynamics using CBLAST Data |
30 SEP 2007 |
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| Authors:
Dick K. Yue; MASSACHUSETTS INST OF TECH CAMBRIDGE
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 | This study uses direct numerical simulation, large-eddy simulation, and large-wave simulation for both air and ocean turbulent flows with surface waves to investigate the dynamics of coupled air-sea boundary layers at relatively small spatial scales. With extensive simulation in collaboration with measurement, we identify and assess the key transport processes within the atmosphere-ocean wave boundary layer (WBL). This project obtains a physical foundation for the parameterization of the momentum, mass ... |
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| Development of a 3-D Defocusing Liquid Crystal Particle Thermometry and Velocimetry (3DDLCPTV) System |
MAY 2007 |
144 pages |
| Authors:
David R. Schmitt; WASHINGTON UNIV SEATTLE
|
| One of the most intriguing and perplexing problems in fluid mechanics today, as it was 50 years ago, is that of turbulence. The behavior of a fluid in turbulent regions around an object consists of chaotic flow phenomena made of unsteady vortices on many scales that can critically affect the ability of that object to pass through the fluid. Indeed, turbulent convective heat and mass transfer is one of the ... |
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| Exergy Analysis for Energy Systems |
SEP 2006 |
195 pages |
| Authors:
Rama S. Gorla; GORLA CONSULTANTS INC STRONGSVILLE OH
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| In Phase Change transport devices, capillary forces drive the overall circulation of working fluid from an evaporator to a condenser section. An analysis has been provided for the entropy generated for the combined heat and mass transfer in a circular tube and micro/nano scale heat and mass transfer in a capillary tube in terms of the gradients of velocity, temperature, and concentration as well as the physical properties of the ... |
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| Mass Transfer from Entrapped DNAPL Sources Undergoing Remediation: Characterization Methods and Prediction Tools |
31 AUG 2006 |
437 pages |
| Authors:
Tissa H. Illangasekare; Junko M. Marr; Robert L. Siegrist; Kenichi Soga; Kent L. Glover; Elena Moreno-Barbero; Jeffery L. Heiderscheidt; Satawat Saenton; Mini Matthew; Ann R. Kaplan; COLORADO SCHOOL OF MINES GOLDEN DIVISION OF ENVIRONMENTAL SCIENCE AND ENGINEERING
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| The primary goal of this research was to understand and characterize mass transfer and tracer partitioning in physically heterogeneous DNAPL sources undergoing remediation. Four source zone treatment technologies were evaluated: (1) bio-treatment, (2) in situ chemical oxidation (ISCO), (3) surfactant enhanced dissolution and (4) thermal treatment. Fundamental knowledge was generated to improve and develop tools for evaluating the impact of remediation technologies on DNAPL distribution in heterogeneous systems. Experiments and ... |
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| Vascular Materials for Human Heat Management and Wound Healing |
31 DEC 2005 |
8 pages |
| Authors:
Abraham Stroock; CORNELL UNIV ITHACA NY
|
| The key to our experimental approach to the creation of Vascular Materials is the development of material syntheses and methods of micro-fabrication that allow us to embed micro-fluidic structure directly within hydrogels. For the operation and characterization of systems (Artificial Leaves, Wound Dressings, and Tissue Scaffolds) based on Vascular Materials, we have developed experiments to control and monitor fluxes of heat and mass in an automated fashion. In parallel, we ... |
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| COAMPS Simulations of the Coastal Atmosphere |
DEC 2005 |
3 pages |
| Authors:
Eric D. Skyllingstad; Roger M. Samelson; OREGON STATE UNIV CORVALLIS
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| Work has focused primarily on simulations of the coastal atmosphere, and on building a coupled regional ocean-atmosphere model, based on the Naval Research Laboratory - COAMPS and Rutgers/UCLA ROMS models, for use on multiple processor, cluster systems. Progress to date includes the development of a processor management code module using the Model Coupling Toolkit (MCT) (Argonne National Laboratory). The management module is able to run both COAMPS and ROMS on ... |
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| Development of an Efficient Micro-Heat Exchanger: The Integration of Design Processing and Testing |
NOV 2005 |
24 pages |
| Authors:
Patrick Kwon; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
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| Many new concepts in designing and fabricating thermal management materials (TMMs) were explored to make an efficient meso-scale heat exchanger. The proposed TMMs have multi-functionality that combines structural material with cooling components by utilizing embedded microstructures in a miniature-sized body to enhance heat and mass transfer, chemical reactions etc. `Mesomachines' are expected to provide a number of important functions where a premium is placed on mobility, compactness, or point application. ... |
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| Regenerative Filtration Test Methodology |
16 NOV 2004 |
19 pages |
| Authors:
Michael Parham; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD RESEARCH AND TECHNOLOGY DIR
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| Advancement and Application of Multiphase CFD Modeling to High Speed Supercavitating Flows |
20 AUG 2004 |
34 pages |
| Authors:
Jules W. Lindau; Robert F. Kunz; PENNSYLVANIA STATE UNIV UNIVERSITY PARK APPLIED RESEARCH LAB
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| Recent progress in the development and application of homogenous multiphase CFD methods for large-scale gas cavities in liquid flows are presented. The focus of the presentation is on work in n-species transport approaches applied to developed and super-cavitation. Numerical formulation, physical modeling, and applications are included. Numerical issues to be discussed include: preconditioning in the context of incompressible through supersonic Mach numbers, arbitrary numbers of species, high density ratios, and ... |
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| Sulfur Tolerance of Carbide Catalysts Under Hydrocarbon Reforming Conditions |
16 AUG 2004 |
9 pages |
| Authors:
William J. Thomson; WASHINGTON STATE UNIV PULLMAN
|
| A three year project to determine the feasibility of molybdenum carbide catalysts for the reforming of hydrocarbon fuels has been completed. As a result of this project, conditions for maintaining the stability of these catalysts under both dry and steam reforming methane have been determined. In particular it has been found that these catalyst can be kept stable by either operating at high temperatures, high pressures or by recycling CO ... |
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| Novel, Solvent Free, Single Ion Conductive Polymer Electrolytes |
AUG 2004 |
58 pages |
| Authors:
Emanual Peled; D. Golodnitsky; TEL-AVIV UNIV (ISRAEL) SCHOOL OF CHEMISTRY
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| Characterization of four types of FeS2-cathodes for the Li/CPE/pyrite battery was carried out by SEM, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and electrochemical methods. Analysis of the experimental data, suggests that for pyrite-based cathodes (obtained by casting, doctor-blade technique and KE sputtering) it is the mass transport of iron cations througout the Li2FeS2 that slows the charge rate and creates a charge overvoltage. |
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| Activated Carbon Fiber Cloth Electrothermal Swing Adsorption System |
14 JUN 2004 |
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| Authors:
Patrick D. Sullivan; Mark J. Rood; George Grevillot; Joseph D. Wander; K. J. Hay; ILLINOIS UNIV AT URBANA DEPT OF CIVIL AND ENVIRONMENTAL ENGINEERING
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| Capture and recovery of hazardous air pollutants (HAPs) and volatile organic compounds (VOCs) from gas streams using physical adsorption onto activated carbon fiber cloth (ACFC) is demonstrated on the bench-scale. This system is regenerated electrothermally, by passing an electric current directly through the ACFC. The adsorbate desorbs from the ACFC, rapidly condenses on the inside walls of the adsorber, and then drains from the adsorber as a pure liquid. Rapid ... |
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| Intensification of Transport Processes in Fluid-Filled Porous Media by Sound Waves. Application to Fuel Cell Technology |
31 JAN 2004 |
85 pages |
| Authors:
Alexander Staroseisky; Igor Fedchenia; Wenlong Li; UNITED TECHNOLOGIES CORP HARTFORD CT
|
| In this work we aim developing a novel theoretical framework to evaluate the feasibility of attaining significant improvement of fuel cells performance and stability by increasing the transport processes in porous partially fluid filled cathode compartment through the application of acoustic and structural waves. We have developed a unified model of structural/acoustic wave propagation in the PEM cathode compartment and coupled it with mass transfer in the porous media. A ... |
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| Fate of Ammonia in the Atmosphere - A Review for Applicability to Hazardous Releases |
22 JAN 2004 |
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| Authors:
Jean J. Renard; Sheryl E. Calidonna; Michael V. Henley; AIR FORCE RESEARCH LAB TYNDALL AFB FL MATERIALS AND MANUFACTURING DIRECTORATE
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| The physical and chemical mechanisms responsible for the removal of ammonia from the atmosphere have been reviewed. Capture by atmospheric moisture (clouds, rain, fog), surface waters (rivers, lakes, seas), and deposition on vegetation and soil constitute the main pathways for ammonia removal from the troposphere. Ammonia catalyzes the atmospheric oxidation of sulfur dioxide to sulfur trioxide and reacts rapidly with acidic components of the atmosphere (sulfuric, nitric, and hydrochloric acids). ... |
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| Analytic Modeling and Experimental Validation of Intumescent Behavior of Charring Heatshield Materials |
JAN 2004 |
142 pages |
| Authors:
Gerald W. Russell; ARMY AVIATION AND MISSILE COMMAND REDSTONE ARSENAL AL
|
| Intumescing heatshield materials have been shown to provide significant thermal protection for missile system environments. The design and use of these materials requires the analytic understanding of a considerable level of thermodynamic phenomena occurring on the surface, as well as in-depth. These phenomena can include in-depth thermochemical decomposition, pyrolysis gas generation and mass transfer, thermophysical property change, thermochemical and mechanical ablation, intumescence or conduction path growth, and boundary layer modification ... |
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| Rigorous Mathematical Modeling of the Adsorption System with Electrothermal Regeneration of the Used Adsorbent |
29 SEP 2003 |
40 pages |
| Authors:
Menka T. Petkovska; BELGRADE UNIV (YUGOSLAVIA) FACULTY OF NANOTECHNOLOGY AND METALLURGY
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| This report results from a contract tasking University of Belgrade as follows: The contractor shall model a known and existing single absorber of the hollow cylinder, several layers of activated carbon cloth. radial gas flow type. Modelling will incorporate: 1. Modeling of adsorption: Models of different complexity (local equilibrium, film mass transfer with or without dispersion, pore-surface diffusion, micropore diffusion and their combinations) of the hollow-cylinder absorber with radial gas ... |
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| High Temperature Protonic Conductors by Melt Growth |
28 MAY 2003 |
46 pages |
| Authors:
Julian M. Fernandez; SEVILLE UNIV (SPAIN)
|
| This report results from a contract tasking Universidad de Sevilla as follows: The objective of the proposed research is to produce single crystal and multiphase ceramic materials of BaCe1-xNdxO3-a and Ba3(CaNb2)O9 that exhibit high temperature protonic conductance and superior mechanical properties at elevated temperatures. Ba3(CaNb2)O9 material systems will be examined across a broad compositional, and therefore microstructural range, that includes but is not limited to additions of Ga, Nd, and ... |
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| Computational Fluid Dynamics Models of Molecularly Imprinted Materials in Microfluidic Channels |
21 MAY 2003 |
|
| Authors:
Cindy K. Webber; M. J. Roberts; NAVAL AIR WARFARE CENTER CHINA LAKE CA POLYMER SCIENCE AND ENGINEERING BRANCH
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| Current research will lead to rapid-prototyping of chemical sensors that utilize microfabricated molecularly imprinted (MI) materials. CFD/CAD software may be used to model flow and chemical binding properties of Ml materials in microfluidic channels. Use of this type of software expedites results when changes in properties are made. The surface concentration of bound analyze on a monolithic molecularly imprinted polymer (MIP) within microfluidic channels can be modeled using its experimental ... |
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| US Navy Evaluation of the High Reynolds' Number Thermal Stability (HiReTS) Test Unit |
23 APR 2003 |
78 pages |
| Authors:
John E. Colbert; Clarence J. Nowack; Richard A. Kamin; Douglas F. Mearns; NAVAL AIR SYSTEMS COMMAND PATUXENT RIVER MD FUELS AND LUBRICANTS DIV
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| The HiReTS was developed by Shell Global Solutions, Fuels Business Group as a small- scale unit for evaluating the thermal stability of jet fuel prior to shipment to the consumer. The HiReTS was designed to operate at high fuel flow rates through a heated, stainless steel tube (capillary) representative of turbulent flow conditions in actual engine fuel injectors. At the standard operating conditions (SOC), the HiReTS has a Reynolds' Number ... |
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| A Process to Make Collagen Scaffolds with an Artificial Circulatory System Using Rapid Prototyping |
APR 2003 |
7 pages |
| Authors:
Eleftherios Sachlos; Nuno Reis; Chris Ainsley; Brian Derby; Jan T. Czernuszka; MANCHESTER UNIV (UNITED KINGDOM) MATERIALS SCIENCE CENTER
|
| Tissue engineering aims to produce biological substitutes to restore or repair damaged human tissues or organs. The principle strategy behind tissue engineering involves seeding relevant cell(s) onto porous 3D biodegradable scaffolds. The scaffold acts as a temporary substrate where the cells can attach and then proliferate and differentiate. Collagen is the major protein constituent of the extracellular matrix in the human body and therefore an attractive scaffold material. Current collagen ... |
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| Blowing Effects on Heat and Mass Transfer for Different Geometrical Configurations |
MAR 2003 |
|
| Authors:
F. Bataille; L. Mathelin; J. Bellettre; A. Lallemand; INSTITUT NATIONAL DES SCIENCES APPLIQUEES DE LYON VILLEURBANNE (FRANCE)
|
| In this paper, the blowing impact on the dynamical and thermal boundary layers is investigated through experiments and numerical simulations. Two different geometries (flat plate and circular cylinder) are separately studied. It is shown that blowing tends to thicken the boundary layers and to dramatically decrease the gradients in the immediate vicinity of the surface, leading to a strong decrease of the viscous stress and heat exchanges. Hence, the surface ... |
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| Research into the Influence of Rotation on the Internal Cooling of Turbine Blades |
MAR 2003 |
11 pages |
| Authors:
D. A. Rowbury; S. Parneix; D. Chanteloup; A. Lees; ROLLS-ROYCE LTD BRISTOL (UNITED KINGDOM)
|
| This paper provides an overview of the on-going work in the Brite- EuRam Internal Cooling of Turbine Blades' (ICTB) project. The project is a collaborative, pan-European research program that brings together partners from industry and academia. The project aims to build an extensive experimental database concerning the effects of rotation on the internal flow distribution and heat transfer levels of rotor blades. The database will be used to develop correlations ... |
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| Area-Preserving Mappings for the Visualization of Medical Structures |
2003 |
9 pages |
| Authors:
Lei Zhu; Steven Haker; Allen Tannenbaum; GEORGIA INST OF TECH ATLANTA BIOMEDICAL RESEARCH DIV
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| In this note, we present a method for flattening anatomical surfaces such as branched vessels and intestinal tracts in an area preserving way. This method is based on the theory of optimal mass transport and conformal mapping of surfaces. The flattened representations differ minimally from conformality in a certain precise sense. Potential applications include the detection and visualization of pathologies such as stenoses and polyps. |
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| Timing Studies of X-Ray Binary Orbits |
2003 |
11 pages |
| Authors:
P. S. Ray; M. T. Wolff; K. S. Wood; P. Hertz; NAVAL RESEARCH LAB WASHINGTON DC E O HULBURT CENTER FOR SPACE RESEARCH
|
| X-ray astronomy, by necessity, involves the study of highly variable stars, nearly all of them in binary systems where one member is a compact object such as a neutron star or black hole. These systems allow us to probe physical effects in regions of extreme gravity, high temperatures, and intense magnetic fields that are characteristic of compact objects and are unattainable in laboratory experiments. By studying the brightness variations and ... |
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| Journal of Crystal Growth Volume 246, Nos. 1-2, pp.1-176, December 2002 |
01 DEC 2002 |
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| Authors:
G. B. Stringfellow; M. Schieber; R. S. Feigelson; D. T. Hurle; R. Kern; ELSEVIER SCIENCE PUBLISHERS AMSTERDAM (NETHERLANDS)
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| Partial Contents: Classical semiconductors. Temperature control in InGaAs-based quantum well Structures grown by molecular beam epitaxy on GaAs (100) and GaAs (111)B substrates; Atomic depth distribution and growth modes of Sn on Si(1111 41-In and alpha-33-Au surfaces at room temperature; Enhanced impurity incorporation by alternate Te and S doping in GaAs prepared by intermittent injection of triethylgallium and arsine in ultra high vacuum; Defect-selective etching of GaN in a modified ... |
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| Modelling of Heat and Mass Transfer Around Single Hot Particle Surrounded by a Vapor Layer and Liquid |
JUL 2002 |
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| Authors:
A. A. Gubaidullin; I. N. Sannikov; E. A. Kosheleva; RUSSIAN ACADEMY OF SCIENCES NOVOSIBIRSK INST OF THEORETICAL AND APPLIED MECHANICS
|
| The investigation of heat and mass transfer process around a single hot particle surrounded by vapor layer and liquid is actual due to a study of vapor explosion in the time of hard accidents on the nuclear reactors and metallurgy industry. The process of heat and mass transfer of vapor bubble at surrounding liquid was investigated well. However, insufficient attention was devoted a similarly process in the case of presence ... |
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| Flow Structure and Mass Transfer Investigation of the Turbulized Boundary Layer with Ethanol Evaporation and Diffusion Combustion |
JUL 2002 |
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| Authors:
E. P. Volchkov; B. F. Boyarshinov; V. I. Titkov; RUSSIAN ACADEMY OF SCIENCES NOVOSIBIRSKINST OF THERMOPHYSICS
|
| Uncertainty of evaluation of each factor (separation laminar- turbulent transition combustion and turbulization) hinders mathematical simulation of the joint effect on gas dynamic and thermal characteristics of the boundary layer. The characteristics may be most reliably determined experimentally. The work objective is the experimental study of the boundary layer structure comparison of the fields of temperature velocity and its pulsation with data on heat and mass transfer. |
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| Numerical Simulation of a Hydrogen Combustion in a Boundary Layer with a Different Blowing Parameters |
JUL 2002 |
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| Authors:
E. P. Volchkov; V. V. Terekhov; B. I. Terekhov; RUSSIAN ACADEMY OF SCIENCES NOVOSIBIRSKINST OF THERMOPHYSICS
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| The current paper presents results of simulation for a turbulent flow with hydrogen blowing into the boundary layer. Since the process has many parameters, the main emphasis was put on analysis of dynamic parameters velocity profiles integral scales and surface friction. |
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| Numerical Simulations of the Flow Around a Circular Cylinder Covered by a Porous Medium |
APR 2002 |
|
| Authors:
Michal P. Sobera; Chris R. Kleijn; Harry E. A. van den Akker; Paul Brasser; PRINS MAURITS LABORATORIUM TNO RIJSWIJK(NETHERLANDS)
|
| In order to develop more comfortable and safe protective garments it is necessary to obtain detailed knowledge of the phenomena governing air flow heat and mass transfer. Computational Fluid Dynamics (CFD) is a promising approach for those kinds of problems. Numerical simulations can support the design process and make it cheaper. Simulations of the air flow in a 2D model of a cylindrical human body part covered by protective clothing ... |
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| A Multi-Tracer Push-Pull Diagnostic Test for Assessing the Contributions of Volatilization and Biodegradation During In Situ Air Sparging |
01 DEC 2001 |
17 pages |
| Authors:
Illa L. Amerson-Treat; Cristin L. Bruce; Richard L. Johnson; Paul C. Johnson; BATTELLE MEMORIAL INST COLUMBUS OH
|
| This paper describes the development and application of a diagnostic tool for local measurements of mass transfer during operation of an IAS system. The diagnostic test involves injecting a solution containing multile tracer compounds through a monitoring well, piezometer, or drive point into the target treatment zone. The injected solution is initially deoxygenated and can contain: (a) a non-degradable, non-volatile conservative tracer, (b) one or more non- degradable, volatile chemicals, ... |
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| Treatment of Volatile Organic Compounds From Gas Streams Using a Three- Phase Circulating-Bed Biofilm Reactor |
APR 2000 |
100 pages |
| Authors:
Byung J. Kim; Haibo Yu; Bruce E. Rittmann; CONSTRUCTION ENGINEERING RESEARCH LAB (ARMY) CHAMPAIGN IL
|
| This study focuses on the biofilm kinetics of removing benzene, toluene, and p-xylene (BTX) from gas streams in a three-phase circulating-bed reactor using porous carriers. In the biofilm reactor, gas-liquid equilibrium existed for BTX, but not for oxygen. Oxygen was consumed as a cosubstrate in the oxygenation reactions and the terminal electron acceptor during respiration. When toluene was the sole substrate, oxygen mostly controlled its removals, ... |
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| Demonstration of a Split-Operator Numerical Method for Modeling Sorption and Degradation Processes |
21 FEB 2000 |
16 pages |
| Authors:
Joseph A. Pedit; Cass T. Miller; NORTH CAROLINA UNIV AT CHAPEL HILL CENTER FOR THE ADVANCED STUDY OF THE ENVIRONMENT; NORTH CAROLINA UNIV AT CHAPEL HILL CENTER FOR THE ADVANCED STUDY OF THE ENVIRONMENT
|
| Mathematical models for simulating contaminant fate and transport often include mass transfer, nonlinear reactions, multiple species, and multiple dimensions. These problems can require significant computational effort. Split operator numerical methods can be used to significantly reduce the computational demands of simulating some of these problems. We demonstrate a split operator numerical method on a model for sorption and degradation processes. |
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| Strip Cell Stack Design and Mass Transfer Phenomena in a Polymer Electrolyte Membrane Fuel Cell Stack |
FEB 2000 |
20 pages |
| Authors:
Rongshong Jiang; Deryn Chu; ARMY RESEARCH LAB ADELPHI MD
|
| A type of air-breathing polymer electrolyte membrane fuel cell (PEMFC) stack with a strip design structure was investigated. Potential-current curves for this PEMFC show typical mass transfer behavior. An empirical equation was developed to describe the kinetic processes of the stack, as opposed to only a single cell. A series of experimental potential-current and power-current curves including different humidities, temperatures, and stack lengths was extremely well ... |
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| Comparative Studies of Polymer Electrolyte Membrane Fuel Cell Stacks andSingle Cells |
FEB 2000 |
22 pages |
| Authors:
Deryn Chu; Rongzhong Jiang; ARMY RESEARCH LAB ADELPHI MD
|
| We made a comparative investigation of a polymer electrolyte membrane fuel cell (PEMFC) with a single cell and a 30 cell stack. Various types of Nafion membranes, such as Nafion 102, 112, 115, and 117, and 105, were tested as electrolytes with the single cell at different temperatures. Nafion 112 gave us the optimal result. We evaluated the 30 cell stack at different temperatures and humidity levels. The ... |
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| Electromagnetic Interaction, Thermal and Mass Transfer Modeling of the Photothermal Modulation of Mie Scattering Spectroscopy of Aerosols |
15 JAN 2000 |
25 pages |
| Authors:
John P. Barton; NEBRASKA UNIV LINCOLN DEPT OF MECHANICAL ENGINEERING
|
| Theoretical procedures were developed, computer programs were written, and demonstration calculations were performed investigating the modeling and predicted performance of the photothermal modulation of Mie scattering (PMMS) spectroscopy method for aerosol diagnostics. |
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| MT3DMS: A Modular Three-Dimensional Multispecies Transport Model for Simulation of Advection, Dispersion, and Chemical Reactions of Contaminants in Groundwater Systems; Documentation and User's |
DEC 1999 |
219 pages |
| Authors:
Chunmiao Zheng; P. P. Wang; ALABAMA UNIV TUSCALOOSA
|
| This manual describes the next generation of the modular three- dimensional transport model, MT3D, with significantly expanded capabilities, including the addition of (a) a third-order total-variation-diminishing (TVD) scheme for solving the advection term that is mass conservative but does not introduce excessive numerical dispersion and artificial oscillation, (b) an efficient iterative solver based on generalized conjugate gradient methods and the Lanczos/ORTHOMIN acceleration scheme to ... |
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| The Transient Response of Rotary Desiccant Wheels Through Experimentation and Numerical Analysis |
19 OCT 1999 |
337 pages |
| Authors:
Stephen D. Grumbach; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
|
| Rotary desiccant wheels are commonly used for industrial dehumidification systems and significant research has also been done to increase their application in other HVAC systems. The transient response is of concern because it can affect system overall performance and previous research efforts have indicated the transient response to be of substantial duration. This research experimentally and analytically investigated the transient response of rotary desiccant ... |
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| An Investigation of the Erosion Physics/Mechanisms of Current Army Systems (Point Studies) |
SEP 1999 |
57 pages |
| Authors:
Paul J. Conroy; Paul Weinacht; Michael J. Nusca; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Future systems performance requirements have led to a heightened awareness of the erosion issue and to the development of erosion investigations in the U.S. Army and Navy. These investigations involve experimental and modeling efforts to understand the thermal, chemical, and mechanical contributions to erosion/wear. A description of the mechanistic erosion representation follows in this report. The calculation procedure is illustrated, including details of the mass transport scheme, gas surface interface, ... |
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| Nasal Heat Probe to Measure Nasal Cavity Heat and Water Vapor Transport |
03 AUG 1999 |
6 pages |
| Authors:
Kambiz Farahmand; Jonathan Kaufman; NAVAL AIR WARFARE CENTER AIRCRAFT DIV PATUXENT RIVER MD
|
| A Nasal-Heat probe was developed to measure intra-airway heat and vapor transfer. The changes in the intra-airway temperature, respiration rate, respiratory heat and water vapor exchange as a result of environmental conditions were easily determined using this device. The humidity profiles generated were closely related to the heat and water vapor exchange. Heat and mass transfer coefficients in the airways were determined from air stream and wall temperatures inside the ... |
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| Modeling and Control for Rapid Thermally Driven Deposition Processes |
JUL 1999 |
61 pages |
| Authors:
Abbas Emami-Naeini; Klavs F. Jensen; Sarbajit Ghosal; Vijay Gupta; SC SOLUTIONS INC SANTA CLARA CA
|
| The objectives of this program were the study of the chemistry of YBCO thin film deposition by MOCVD, and the model-based control of MOCVD reactors. Model reduction techniques were applied to chemical vapor deposition (CVD) of YBCO thin films. This work has paralleled some of the work of Goodwin et al at Caltech sponsored under the DARPA VIP Phase I program, but with significantly different approach and emphasis. Under this ... |
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| Theoretical and Computational Studies of Nucleation in Supercritical Fuels |
28 JUN 1999 |
14 pages |
| Authors:
Pablo G. Debenedetti; PRINCETON UNIV NJ DEPT OF CHEMICAL ENGINEERING
|
| The principal objective of this research is to improve basic understanding of the deposit of pyrolytic products from thermally-stressed endothermic fuels. The precipitation of picene from supercritical methylcyclohexane was investigated numerically. The calculations indicated that a negligible amount of deposits were formed as a result of friction-driven depressurization in tubular flow. However, the presence of small amounts of particulate impurities dramatically enhanced the rate of deposit formation. Mathematical models were ... |
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| Viscous Effects in Pore Scale Modeling of Immiscible Fluid Flow Through Porous Media |
01 MAY 1999 |
99 pages |
| Authors:
Deanna S. Durnford; Heather H. Trantham; COLORADO STATE UNIV FORT COLLINS
|
| Sites contaminated with dense nonaqueous phase liquids (DNAPLs) such as chlorinated solvents are, typically, exceptionally difficult to characterize because the unstable nature of the front results in complex distributions that are erratic, highly fingered and sensitive to small-scale heterogeneities. However, DNAPL source zone characterization is important for risk assessments, feasibility studies and identification of appropriate remediation technologies at DNAPL-contaminated sites. The extent and configuration of the source zone is also ... |
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| Effect of Temperature on Water Vapor Transport Through Polymer Membrane Laminates |
FEB 1999 |
50 pages |
| Authors:
Phillip Gibson; ARMY SOLDIER AND BIOLOGICAL CHEMICAL COMMAND NATICK MA
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| This report determines the extent to which the water vapor transport properties of nine different polymer membranes and membrane/textile laminates are affected by temperature. A particular test method, the Dynamic Moisture Permeation Cell (DMPC), is ideally suited for this type of study, due to its complete control over the humidity and gas flow rate on the two sides of the test sample, and the ability ... |
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| Investigation of Fluid Flow and Contaminant Transport Processes in Heterogeneous Multiphase Systems |
08 JAN 1999 |
31 pages |
| Authors:
Cass T. Miller; NORTH CAROLINA UNIV AT CHAPEL HILL
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| This final technical report summarizes the goals, objectives, experimental results, and continuum and stochastic modeling results from an University Research Initiative project focused on multiphase fluid flow and contaminant transport processes in heterogeneous multiphase systems. This reportalso annotates the many journal articles, book chapters, reports, newsletter articles, and professional meeting presentations and abstracts produced from this project, and lists the post doctoral associates, doctoral students, and masters students supported by ... |
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| Modeling Semiconductor and Quartz Crystal Growth |
DEC 1998 |
54 pages |
| Authors:
Stafan Balint; UNIVERSITY OF WEST TIMISOARA (ROMANIA)
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| This report results from a contract tasking West University of Timisoara as follows: The contractor will investigate an improved mathematical model of mass and heat transport by convection and diffusion during semiconductor crystal growth utilizing the Bridgman-Stockbarger and hydrothermal methods. |
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| European Conference on Silicon Carbide and Related Materials (2nd), Held in Montpeller, France on September 2-4, 1998 |
04 SEP 1998 |
318 pages |
| Authors:
MONTPELLIER UNIV (FRANCE)
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| Partial Contents: (1) Progress in SiC: from material growth to commercial device development; (2) Advances in SiC materials and devices: an industrial point of view; (3) State of the art in the modelling of SiC sublimation growth; (4) Mathematical simulation of mass transfer, thermal transfer, and stress formation under silicon carbide boules growth; (5) Transport phenomena during sublimation growth of bulk SiC crystals; (6) Near- thermal equilibrium growth of SiC ... |
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Reports by Keyword(s)
MASS TRANSFER
