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Articles 68641 - 68670 of 75068

Full-Text Articles in Engineering

Stochastic Interpolation Of Precipitation Data From Multiple Sensors, D. J. Seo, A. Azimi-Zonooz, D. S. Bowles, W. F. Krajewski, C. J. Duffy, K. P. Georgakakos, T. H. Lee Jan 1988

Stochastic Interpolation Of Precipitation Data From Multiple Sensors, D. J. Seo, A. Azimi-Zonooz, D. S. Bowles, W. F. Krajewski, C. J. Duffy, K. P. Georgakakos, T. H. Lee

Reports

Introduction: This report summarizes the work conducted under Grant No. ECE-8419189, "Stochastic Interpolation of Precipitation Data from Multiple Sensors," which was awarded to Utah State University in September, 1985, and completed February 29, 1988. it also covers work under a supplemental award made in February, 1986. The final report is organized into four sections. The following section presents the objective of the research and a brief problem statment. Section 3 contains a summary of second-year work including the project team, work plan, work completed, and publications. In Section4, project conclusions are summarized. A summary of on-going future work is given …

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Great Salt Lake Interisland Diking: Water Quality Considerations, John I. Blandamer, William J. Doucette, Ryan R. Dupont, Anthony W. Grover, James Herrick, Jean M. Ihnat, Joan E. Mclean, Michael W. Nath, Samuel R. Rushforth, Judith L. Sims, Ronald C. Sims, Wayne A. Wurtsbaugh Jan 1988

Great Salt Lake Interisland Diking: Water Quality Considerations, John I. Blandamer, William J. Doucette, Ryan R. Dupont, Anthony W. Grover, James Herrick, Jean M. Ihnat, Joan E. Mclean, Michael W. Nath, Samuel R. Rushforth, Judith L. Sims, Ronald C. Sims, Wayne A. Wurtsbaugh

Reports

No abstract provided.

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Friction Factor Tests On High Density Polyethylene Pipe, Steven L. Barfuss Jan 1988

Friction Factor Tests On High Density Polyethylene Pipe, Steven L. Barfuss

Reports

No abstract provided.

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Vilma (Virtually Interactive Large Scale Model For Arkansas), Rosalinda R.A. Cantiller, Richard C. Peralta Jan 1988

Vilma (Virtually Interactive Large Scale Model For Arkansas), Rosalinda R.A. Cantiller, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

This user’s guide supports the use of VILMA (Virtually Interactive Large-scale Model for Arkansas). This document presents the basic concepts in Chapter I. Chapter II discusses the execution steps that the user follows during a VILMA session. Chapter III provides a detailed illustration of example data files. Chapter IV presents two example VILMA sessions. Finally, Chapter V elaborates on additional concepts. The Appendices consist of relevant program listings, instructions, and example files. In this user’s guide, the word "interactive" means the user enters his responses to the prompts that appear on a computer terminal while he is logged on to …

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Matrix Methods Of Approximating Classical Predator-Prey Problems, E. Y. Rodin, R. Greenberg, B. Nelson Jan 1988

Matrix Methods Of Approximating Classical Predator-Prey Problems, E. Y. Rodin, R. Greenberg, B. Nelson

Computer Science: Faculty Publications and Other Works

No abstract provided.

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Oxygen Tension Profiles In Tumors Predicted By A Diffusion With Absorption Model Involving A Moving Free Boundary, B. H. Arve, Athanasios I. Liapis Jan 1988

Oxygen Tension Profiles In Tumors Predicted By A Diffusion With Absorption Model Involving A Moving Free Boundary, B. H. Arve, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

The dynamic behavior of the oxygen tension distribution in tumors during radiotherapy is studied by the development and solution of a diffusion with absorption model involving a moving free boundary. The oxygen uptake rates within the tumor are considered to be functions of the oxygen concentration and results are presented for zeroth-, half-, first- and second-order rates of absorption, as well as when the rate of oxygen absorption is described by the Michaelis-Menten expression. The results presented in this work may be used together with the data from the oxygen radiosensitivity curve of a tumor, in order to determine the …

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Synthesizing Inductive Expertise, Daniel N. Osherson, Michael Stob, Scott Weinstein Jan 1988

Synthesizing Inductive Expertise, Daniel N. Osherson, Michael Stob, Scott Weinstein

University Faculty Publications and Creative Works

We consider programs that accept descriptions of inductive inference problems and return machines that solve them. Several design specifications for synthesizers of this kind are considered from a recursion-theoretic perspective.

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Three-Position Function Generation Of Planar Four-Bar Mechanisms With Equal Deviation Transmission Angle Control, Clark R. Barker, Gwo Huey Shu Jan 1988

Three-Position Function Generation Of Planar Four-Bar Mechanisms With Equal Deviation Transmission Angle Control, Clark R. Barker, Gwo Huey Shu

Mining Engineering Faculty Research & Creative Works

This paper is an extension of earlier work on mapping of three-position function generation of planar four-bar mechanisms. Previously, it has been shown that all of the potential solutions to a given problem may be represented in an aft plane which can be subdivided into mechanism types. Further, the regions in the aft plane may represent two possible forms of assembly plus a change of form class which are not valid solutions. In this paper, we provide a third-order polynomial which defines the locus in the aft-plane of solutions which have equal deviation of their transmission angle from the ideal …

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Aircraft Vertical Profile Implementation Using Directed-Graph Methods, L. T. Brewster, Paul D. Stigall Jan 1988

Aircraft Vertical Profile Implementation Using Directed-Graph Methods, L. T. Brewster, Paul D. Stigall

Electrical and Computer Engineering Faculty Research & Creative Works

Aircraft Vertical Profile Simulation is Realized using a Demand-Driven Minimal-Calculation Directed Graph Structure to Reduce Calculation Time and to Force Synchronization of the Performance Measurement Functions with the System State Variables. Performance-Directed Model Adaptation Makes Dynamic Vertical Profile Path Corrections, in the Presence of Fixed Drag Variations, Possible. Drag Variations Ranging from + 10 Percent to - 10 Percent Yielded Fuel Consumption Improvements of Less Than 1 Percent in the Majority of the Cases. Calculation Time Improvement for Path Simulation Ranges from a Factor of 1.19 in the Worst Case to 1.5 in the Best Case. © 1988 IEEE

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Condensation Method For Humidity Measurement In The Umr Cloud Simulation Chamber., Donald E. Hagen, Daniel R. White, Darryl J. Alofs Jan 1988

Condensation Method For Humidity Measurement In The Umr Cloud Simulation Chamber., Donald E. Hagen, Daniel R. White, Darryl J. Alofs

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A Cloud Simulation Facility Has Been Developed for the Study of Various Atmospheric Cloud Processes. the Initial Relative Humidity of the Air Sample Put into the Cloud Chamber is a Key Parameter in Virtually Any Experiment and Needs to Be Known Accurately. This Report Describes How the Cloud Simulation Chamber itself Has Been Used as a Condensation Type Hygrometer to Calibrate the System's Humidifier. Two Distinct and Physically Different Methods for Inferring Mixing Ratio Are Used, One Exploiting the Sensitivity of Aerosol Activation to Humidity, and the Other Exploiting the Sensitivity of the Rate of Growth of Cloud Droplets to …

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Microstructural Analysis In Processing Of The High‐Tc Superconductor Ba2ycu3o7‐X In Air, Jyoti P. Guha Jan 1988

Microstructural Analysis In Processing Of The High‐Tc Superconductor Ba2ycu3o7‐X In Air, Jyoti P. Guha

Materials Science and Engineering Faculty Research & Creative Works

In the synthesis of the superconducting compound Ba2YCu3O7‐x from a stoichiometric mixture containing BaCO3, Y2O3, and CuO In air, a low‐melting liquid phase is formed at about 890°C. The liquid phase was identified as a ternary eutectic located within the compatibility triangle Ba2YCu3O7‐x–BaCuO2–CuO. The implication of this finding for the processing of Ba2YCu3O7‐x is discussed. Copyright © 1988, Wiley Blackwell. All rights reserved.

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Power Filter Resonant Frequency Modulation Network, Don Cronin Jan 1988

Power Filter Resonant Frequency Modulation Network, Don Cronin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A power filter resonant frequency modulation network for coupling between a load and a variable voltage direct current power source which is subjected to superposition of alternating current thereon at various frequencies and at various voltage levels, the filter including first and second series inductor arrangements in the positive and negative buses between the power supply and the load, with capacitive elements in parallel between the two buses. Each series inductor arrangement includes a first inductor in series with a frequency and voltage responsive inductive load device, which is a second inductor having a tertiary winding loaded with a coil …

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Linear State Variable Dynamic Model And Estimator Design For Allison 1406 Gas Turbine Engine, Vittal S. Rao, D. Moellenhoff, J. A. Jaeger Jan 1988

Linear State Variable Dynamic Model And Estimator Design For Allison 1406 Gas Turbine Engine, Vittal S. Rao, D. Moellenhoff, J. A. Jaeger

Electrical and Computer Engineering Faculty Research & Creative Works

This paper describes a procedure for developing a State Variable Model for the Allison T406 gas turbine engine. This linear model is useful for designing controllers using modern control techniques. The engine and V-22 rotor system is modeled around an operating point by using four state variables and one input variable. For a given power setting, it is observed that two linear models are sufficient to represent the engine dynamics over the entire flight envelope. A relationship between surge margin and the state variables is also developed. It is demonstrated that these linear models are useful in designing an estimator …

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Distribution Automation For The Association Of Missouri Electric Cooperatives—A Statewide Evaluation Of Load Management, Jack F. Morris, Frank J. Kern Jan 1988

Distribution Automation For The Association Of Missouri Electric Cooperatives—A Statewide Evaluation Of Load Management, Jack F. Morris, Frank J. Kern

Electrical and Computer Engineering Faculty Research & Creative Works

Presented is an in-depth technical and economic feasibility study utilizing one- and two-way management systems for statewide load control and distribution automation. Included are 1) an evaluation of the generation and transmission load patterns of the state cooperatives and the determination of the amount of controllable load for use by a load management system, 2) an in-depth economic cost-benefit study as a result of implementing a load management system on a statewide basis, 3) communication alternatives for implementing the statewide load management and distribution automation system, 4) an investigation into using an existing statewide microwave communications system for direct load …

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Simulation Of Photovoltaic Power Systems And Their Performance Prediction, S. Rahman, Badrul H. Chowdhury Jan 1988

Simulation Of Photovoltaic Power Systems And Their Performance Prediction, S. Rahman, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

A number of photovoltaic (PV) performance-analysis models are tested for their ability to estimate the AC power output and validated against historical observations from a PV test facility. A method to estimate meteorological parameters is developed for use in PV performance models for predicting future AC power output from a PV test site. Twelve such PV performance models are examined, and the PVFORM system analysis program and lifetime cost and performance models are extensively tested. These two models are tested using the typical meteorological year and the VPI model-generated estimates of long-term data. Performance prediction results are compared against actual …

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Still-Frame Image Transmission Using Dpcm/Interpolative Coding, Brindala Mallappa, Norman R. Cox Jan 1988

Still-Frame Image Transmission Using Dpcm/Interpolative Coding, Brindala Mallappa, Norman R. Cox

Electrical and Computer Engineering Faculty Research & Creative Works

Two methods of combining DPCM (differential pulse-code modulation) and interpolation are proposed for compressing still-frame teleconferencing signals. The first method uses horizontal subsampling, DPCM, and interpolation to achieve a 4:1 compression. The other method is similar but uses vertical subsampling instead. Simulation results indicate that either method can easily achieve the required 2-b/pel data rate with negligible degradation in image quality. Conventional DPCM is shown to perform slightly better in quantitative terms when fixed-wordlength coding is used. However, the two DPCM/interpolation methods offer other advantages when used with a variable-wordlength coder

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A Rule-Based Dynamic Economic Dispatch For Power Systems, Badrul H. Chowdhury Jan 1988

A Rule-Based Dynamic Economic Dispatch For Power Systems, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

The author introduces a novel operation tool for economic dispatch. It deals with the development and implementation of a new approach-a dynamic rule-based dispatch algorithm that takes into account the major problems faced by the dispatch operator during a dispatch interval and channels those into a database for use by a rule-based system. The algorithm is very fast and can be used effectively in interconnected systems. It can also handle renewable technologies and is therefore considered useful for major electric power utilities contemplating adding a significant amount of these new generation sources to their existing mix

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A Discussion On The Diversity In The Applications Of Photovoltaic Systems, S. Rahman, Badrul H. Chowdhury, M. A. Khallat Jan 1988

A Discussion On The Diversity In The Applications Of Photovoltaic Systems, S. Rahman, Badrul H. Chowdhury, M. A. Khallat

Electrical and Computer Engineering Faculty Research & Creative Works

References on the diverse applications of photovoltaic (PV) systems around the world are classified. The classes presented are (i) stand-alone, (ii) grid-connected, (iii) PV-thermal, (iv) PV-wind, and (v) dedicated applications. 73 papers are cited and classified into these five categories including a brief summary of each paper. Out of these, 42 papers relate to grid-connected applications in many industrialized countries of the world. These papers reflect the importance given to such applications. Due to the rapidly changing nature of PV and related industries, only papers published during the last ten years are considered.

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A Practical C Language Compiler/Optimizer For Real-Time Implementations On A Family Of Floating Point Dsps, J. Hartung, Steven L. Grant, S. G. Haigh Jan 1988

A Practical C Language Compiler/Optimizer For Real-Time Implementations On A Family Of Floating Point Dsps, J. Hartung, Steven L. Grant, S. G. Haigh

Electrical and Computer Engineering Faculty Research & Creative Works

Digital signal processors (DSPs) have traditionally been used in real-time applications with very high data throughput. For this reason, system designers have been reluctant to accept the degradation in performance inherent in machine code compiled from high-level languages such as C. The problem is compounded by the fact that DSPs use pipelined architectures to achieve their high data throughput, resulting in hazards and latencies between instructions. Simple compiler implementation cannot take advantage of latent instructions, resulting in a conservative and inefficient executable program. This problem has been addressed in the C compiler package for the AT&T WE DSP32 by the …

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The Distribution Of Chlorine And Iodine In Soil In The Vicinity Of Lead Mining And Smelting Operations, Bixby Area, S.E. Missouri, U.S.A., R. Fuge, M. J. Andrews, T. E. Clevenger, B. E. Davies, Nord L. Gale, C. F. Paveley, B. (Bobby) G. Wixson Jan 1988

The Distribution Of Chlorine And Iodine In Soil In The Vicinity Of Lead Mining And Smelting Operations, Bixby Area, S.E. Missouri, U.S.A., R. Fuge, M. J. Andrews, T. E. Clevenger, B. E. Davies, Nord L. Gale, C. F. Paveley, B. (Bobby) G. Wixson

Biological Sciences Faculty Research & Creative Works

Iodine and Cl are enriched in soils in the vicinity of the Magmont and Buick lead mines near Bixby, southeastern Missouri. The enrichments, up to 5.6 ppm I and 305 ppm Cl, are against regional background of 1.26 ppm I and 41 ppm Cl. The area of highest I and Cl is thought to reflect a zone of base metal sulphide mineralization occurring about 400 m below the surface. Iodine and Cl are also enriched in soils immediately adjacent to a tailings pond, hence these elements would appear to be leached from this source. A zone of enhanced I values …

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Is Central Station Photovoltaic Power Dispatchable?, Badrul H. Chowdhury, S. Rahman Jan 1988

Is Central Station Photovoltaic Power Dispatchable?, Badrul H. Chowdhury, S. Rahman

Electrical and Computer Engineering Faculty Research & Creative Works

An operational tool for integrating a photovoltaic system into the utility's generation mix is introduced. The development and implementation of a new approach-a dynamic rule-based (RB) dispatch algorithm-is presented. A Box-Jenkins time-series method is used to model the subhourly solar irradiance. The model is extended to yield forecast parameters which are then used to predict the photovoltaic output expected to occur at certain lead times coinciding with the economic dispatch intervals. The RB dispatch algorithm is introduced to operate as either a substitute for or an aid to the dispatch operator. It is concluded that results depend on the time …

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Sealing Glasses For Titanium And Titanium Alloys, Richard K. Brow, R. D. Watkins Jan 1988

Sealing Glasses For Titanium And Titanium Alloys, Richard K. Brow, R. D. Watkins

Materials Science and Engineering Faculty Research & Creative Works

Glass compositions containing calcium oxide, alumina, boric oxide, strontium oxide and barium oxide in various mole % combinations were studied. These compositions are capable of forming stable glass to metal seals with titanium and titanium alloys for use as seals for battery headers.

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Implementation Of Dsp Applications Using The At&T Dsp32 C Compiler And Application Library, J. Tow, J. Hartung, Steven L. Grant Jan 1988

Implementation Of Dsp Applications Using The At&T Dsp32 C Compiler And Application Library, J. Tow, J. Hartung, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

The authors briefly introduce the C compiler and the application library for the DSP32 digital signal processor (DSP). Several examples are shown that illustrate the ease of writing C programs for some common filtering applications. In most cases, a small real-time penalty is incurred by using C, rather than assembly language coding. Programming in C, however, allows a dramatic improvement in programmer productivity in terms of implementing, testing, and maintaining an application

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New Directions In Subband Coding, Y. Shoham, Steven L. Grant, N. Seshadri, R. V. Cox, S. R. Quackenbush, N. S. Jayant Jan 1988

New Directions In Subband Coding, Y. Shoham, Steven L. Grant, N. Seshadri, R. V. Cox, S. R. Quackenbush, N. S. Jayant

Electrical and Computer Engineering Faculty Research & Creative Works

Two very different subband coders are described. The first is a modified dynamic bit-allocation-subband coder (D-SBC) designed for variable rate coding situations and easily adaptable to noisy channel environments. It can operate at rates as low as 12 kb/s and still give good quality speech. The second coder is a 16-kb/s waveform coder, based on a combination of subband coding and vector quantization (VQ-SBC). The key feature of this coder is its short coding delay, which makes it suitable for real-time communication networks. The speech quality of both coders has been enhanced by adaptive postfiltering. The coders have been implemented …

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Dynamic Timoshenko Beam-Columns On Elastic Media, Franklin Y. Cheng, Chris P. Pantelides Jan 1988

Dynamic Timoshenko Beam-Columns On Elastic Media, Franklin Y. Cheng, Chris P. Pantelides

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Differential equations, stiffness coefficients, and fixed-end forces are formulated for a Timoshenko beam-column on an elastic foundation subjected to lateral time-dependent excitations and static axial loads. The theoretical formulation includes shear and bending deformations as well as rotatory inertia, with emphasis on two approaches. The two approaches differ in terms of the assumed shear component of the static axial load on the cross section. The first approach is based on the assumption that the shear component of the axial load is calculated from the total slope; in the second approach, the shear component of the axial load is calculated only …

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Static Timoshenko Beam-Columns On Elastic Media, Franklin Y. Cheng, Chris P. Pantelides Jan 1988

Static Timoshenko Beam-Columns On Elastic Media, Franklin Y. Cheng, Chris P. Pantelides

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Two approaches are used to derive differential equations, stiffness coefficients, and fixed-end forces for the analysis of structural systems composed of Timoshenko beam-columns that may be supported by an elastic foundation. The analysis is for the evaluation of the critical static axial load and buckling mode-shapes of a structure with consideration of elastic media, bending, and shear deformations. The two approaches differ in terms of the assumed shear component of the static axial load on the cross section. The first approach is based on the assumption that the shear component of the axial load is calculated from the total slope, …

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Improved Streamline-Generating Technique That Uses The Boundary (Integral) Element Method, Daopu Thompson Numbere, D. Tiab Jan 1988

Improved Streamline-Generating Technique That Uses The Boundary (Integral) Element Method, Daopu Thompson Numbere, D. Tiab

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The boundary element method (BEM) has been used to generate streamlines for homogeneous and sectionally homogeneous reservoirs having irregular boundaries. This technique is superior to earlier methods that use 'image wells' to simulate the reservoir boundary, especially for cases where the reservoir boundary is irregularly shaped. It has wider applicability to different kinds of reservoirs and eliminates the need for trial-and-error solutions. The errors caused by discretization and numerical approximation arise on and adjacent to the boundaries only, therefore the pressures and pressure gradients on which the streamlines are derived can be calculated with very high accuracy in the interior …

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A Stochastic Model For Dielectric Breakdown In Thin Capacitors, D. A. Willming, Cheng-Hsiao Wu Jan 1988

A Stochastic Model For Dielectric Breakdown In Thin Capacitors, D. A. Willming, Cheng-Hsiao Wu

Electrical and Computer Engineering Faculty Research & Creative Works

A nontrivial two-dimensional stochastic model for dielectric breakdown within a parallel plate capacitor is presented for the first time. The model has been used to determine geometric properties of parallel plate discharges. Comparisons are made between these properties and known fractal properties of electrostatic discharges within cylindrical geometries. As the spacing between the plates of a capacitor increases, the value of the fractal dimension of the associated discharge structure increases from the minimum value of unity and approaches the limiting value corresponding to the case of infinite spacing. For any given spacing, this fractal exponent is equal to the exponent …

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On The Use Of A Modified Square-Well Model For Prediction And Correlation Of Thermal Diffusion Factors In Binary Liquid Mixtures, Richard L. Rowley, S. C. Yi Dec 1987

On The Use Of A Modified Square-Well Model For Prediction And Correlation Of Thermal Diffusion Factors In Binary Liquid Mixtures, Richard L. Rowley, S. C. Yi

Faculty Publications

Recently reported thermal diffusion factors obtained from heats of transport have been used to test the ability of existing theories to predict thermal diffusivities using model parameters regressed from pure component transport data. None of the theories tested were able to provide even qualitative agreement with experiment. However, predictions using a square-well Enskog theory, modified here for consistency with normal experimental definitions, were found to be approximately correct using pure-component square-well parameters regressed from viscosity and thermal conductivity and an assumed mixing rule for cross terms. Predicted values are very sensitive to the energy mixing rule, and correlation of experimental …

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Two-Dimensionat Studies Of Streamers Fn Gases, S. K. Dhali, P. F. Williams Dec 1987

Two-Dimensionat Studies Of Streamers Fn Gases, S. K. Dhali, P. F. Williams

P. F. (Paul Frazer) Williams Publications

We present the results of two-dimensional computer simulations of streamer initiation and propagation in atmospheric pressure N2. The simulation algorithm makes use of flux-corrected transport techniques and was used as a tool to study the solutions of the transport equations under conditions suitable for streamers, for which realistic analytic solutions are not known. We present and discuss conclusions about streamer transport based on the results of these studies. Finally, we present a novel method of checking on the numerical accuracy with which the algorithm solves the transport equations.

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