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Faculty Publications

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Articles 3241 - 3270 of 3281

Full-Text Articles in Engineering

Parallel Plate Electrochemical Reactor Model: Material Balance Closure And A Simplification, M J. Mader, C W. Walton, Ralph E. White Jan 1986

Parallel Plate Electrochemical Reactor Model: Material Balance Closure And A Simplification, M J. Mader, C W. Walton, Ralph E. White

Faculty Publications

A material balance closure calculation is presented to test the consistency of a previously published model of a parallelplate electrochemical reactor. New expressions are used in this procedure to calculate the average concentration of species i and the average current density for reaction j from the predicted concentration and potential distributions. Also, the previously presented model equations are simplified by assuming that the axial concentration gradient for species i can be approximated by a step change from the known feed concentration to the unknown outlet concentration. This one-step model provides a qualitative evaluation of cell performance and adds insight into …

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A Mathematical Model For A Parallel Plate Electrochemical Reactor, Cstr, And Associated Recirculation System, T V. Nguyen, C W. Walton, Ralph E. White Jan 1986

A Mathematical Model For A Parallel Plate Electrochemical Reactor, Cstr, And Associated Recirculation System, T V. Nguyen, C W. Walton, Ralph E. White

Faculty Publications

A mathematical model is presented for a system comprised of a parallel plate electrochemical reactor (PPER) and a continuous, stirred-tank reactor (CSTR) under both total and partial recycle. The model is used to predict the time dependent behavior of the electrowinning of copper from an aqueous, hydrochloric acid solution. The model includes many important aspects of a PPER/CSTR system which have been neglected previously. These aspects are the kinetics of electrode reactions, the electroneutrality condition, three mass transfer processes for ionic species in the electrolyte (diffusion, ionic migration, and convection) and the electrode gap in the PPER, and the inclusion …

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A Theoretical Basis For Practical Amplifier Design Using Cascaded Operational Amplifiers, David J. Comer Aug 1985

A Theoretical Basis For Practical Amplifier Design Using Cascaded Operational Amplifiers, David J. Comer

Faculty Publications

A procedure is developed for the design of amplifiers to meet specified gain and bandwidth figures. The number of required operational amplifier stages is minimised. A figure of merit is introduced to determine if a particular operational amplifier can be used to satisfy a given set of specifications.

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High Discharge Rate Characteristics Of Nickel-Cadmium Batteries For Pulse Load Filtering, Gregory M. Gearing, Michael B. Cimino, David H. Fritts, John F. Leonard, Anthony J. Terzuoli Jr. Jul 1985

High Discharge Rate Characteristics Of Nickel-Cadmium Batteries For Pulse Load Filtering, Gregory M. Gearing, Michael B. Cimino, David H. Fritts, John F. Leonard, Anthony J. Terzuoli Jr.

Faculty Publications

Several tests of specially fabricated nickel-cadmium batteries having circular disk type electrodes were considered. These batteries were evaluated as filter elements between a constant current power supply and a five hertz pulsed load demanding approximately twice the power supply current during the load on portion of the cycle. Short tests lasting 10,000 cycles were conducted at up to a 21 C rate and an equivalent energy density of over 40 Joules per pound. In addition, two batteries were subjected to 107 charge/discharge cycles, one at a 6.5 C rate and the other at a 13 C rate. Assuming an …

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Industrial Earthquake Preparedness In Shizuoka And The Role Of The Prefectural Government, Guna S. Selvaduray Feb 1985

Industrial Earthquake Preparedness In Shizuoka And The Role Of The Prefectural Government, Guna S. Selvaduray

Faculty Publications

The Shizuoka Prefectural Office in Japan plays an important role in promoting earthquake emergency preparedness among its industries. In addition to implementing regulatory requirements and enacting new regulations as necessary, the Prefectural Office also provides significant guidance to industry. This includes making publications available and periodic surveys of the status of industrial emergency preparedness. A pharmaceutical company in the prefecture has developed an impressive earthquake preparedness program and hazard reduction techniques. This program addresses both primary and secondary effects of earthquakes.

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Modeling And System Identification Of Residential Air Conditioning Load, Anil Pahwa, Charles W. Brice Jan 1985

Modeling And System Identification Of Residential Air Conditioning Load, Anil Pahwa, Charles W. Brice

Faculty Publications

A fairly detailed physically-based model of the residential air condit$ oning system is presented. It has been shown that the paramstors of tho model can be identified by making a sequenco of measuremonts of on/off cycles of the air conditioner and the onvironment variables. A scheme to determine aggregate demand of the air conditionors using duty factors is presented. The effect on energy consumption and poak duty fa9tor of change in model parameters is determined. Also, the effect of reduction in the supply voltage is studied using this model and it has been found that the steady state air conditioning …

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Using Parameter Estimation Techniques With A Simple Model Of A Diaphragm-Type Electrolyzer To Predict The Electrical Energy Cost For Naoh Production, John Van Zee, Ralph E. White Jan 1985

Using Parameter Estimation Techniques With A Simple Model Of A Diaphragm-Type Electrolyzer To Predict The Electrical Energy Cost For Naoh Production, John Van Zee, Ralph E. White

Faculty Publications

Predictions of the electrical energy cost for NaOH production are determined as a function of the independent operating variables and diaphragm characterizing properties. The predictions are based on data from a statistically designed experiment, a simple model of a diaphragm-type electrolyzer, a simple model of the cell voltage losses, and parameter estimation techniques. The data were obtained over a sufficiently large range of operating conditions so that the resulting design equation may be industrially useful. The simple model of the diaphragm is based on the mass transport of the hydroxyl ion, a linear potential gradient, and is presented in terms …

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Extension Of Darby's Model Of A Hydrophylic Gas Fed Porous Electrode, Ralph E. White, M. A. Nicholson, L. G. Kleine, J. Van Zee, R. Darby Jan 1984

Extension Of Darby's Model Of A Hydrophylic Gas Fed Porous Electrode, Ralph E. White, M. A. Nicholson, L. G. Kleine, J. Van Zee, R. Darby

Faculty Publications

A model presented previously by one of the authors (1,2) is reviewed and extended. Aspects of this model which were not previously available in the open literature are considered, and the model is extended to include previously neglected terms in the governing differential equations, fractional reaction orders in the current density-overpotential expression, and mass-transfer coefficients to account for mass-transfer resistance of the reactants to the faces of the porous electrode. The model is used to predict quantities of interest for oxygen reduction in an acidic aqueous solution in a porous carbon electrode.

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A Model Of The Bromine/Bromide Electrode Reaction At A Rotating Disk Electrode, Ralph E. White, S. E. Lorimer Jan 1983

A Model Of The Bromine/Bromide Electrode Reaction At A Rotating Disk Electrode, Ralph E. White, S. E. Lorimer

Faculty Publications

A mathematical model is presented for the Br2/Br– electrode reaction at a rotating disk electrode. The model includes current density-overpotential expressions for the electrode reaction according to either the Volmer-Heyrovsky (V-H) or the Volmer-Tafel (V-T) mechanism and the transport equations including the effect of ionic migration. The model is used to predict current-overpotential curves for various cases of interest. Qualitative comparison of the model predictions to literature data shows that either the V-H or the V-T mechanism, with V controlling, may be acceptable for the Br2/Br– reaction.

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An Analysis Of A Back Fed Porous Electorde For The Br2/Br- Redox Reaction, John W. Van Zee, Ralph E. White Jan 1983

An Analysis Of A Back Fed Porous Electorde For The Br2/Br- Redox Reaction, John W. Van Zee, Ralph E. White

Faculty Publications

No abstract provided.

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Parallel Plate Electrochemical Reactor Model, Ralph E. White, Mike Bain, Mike Raible Jan 1983

Parallel Plate Electrochemical Reactor Model, Ralph E. White, Mike Bain, Mike Raible

Faculty Publications

No abstract provided.

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Prediction Of The Current Density At An Electrode At Which Multiple Electrode Reactions Occur Under Potentiostatic Control, Ralph E. White, S. E. Lorimer, R. Darby Jan 1983

Prediction Of The Current Density At An Electrode At Which Multiple Electrode Reactions Occur Under Potentiostatic Control, Ralph E. White, S. E. Lorimer, R. Darby

Faculty Publications

It is often desirable to be able to predict the total current density at an electrode when multiple electrochemical reactions occur there under potentiostatic control. It is also sometimes desirable to include the effect of ionic migration within the diffusion layer upon the predicted total (1) and partial current densities (2). A procedure for doing this can be illustrated by considering the rotating disk electrode (RDE) system and the associated potential distribution near the RDE as shown in Fig. 1 and 2.

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An Analysis Of A Back Fed Porous Electrode For The Br2/Br Reaction, John Van Zee, Ralph E. White Jan 1983

An Analysis Of A Back Fed Porous Electrode For The Br2/Br Reaction, John Van Zee, Ralph E. White

Faculty Publications

An experimental analysis of the Br2/Br– redox reaction in a porous back fed ruthenium-coated titanium electrode is described. A mathematical model of the steady-state process is presented. Nonlinear regression of the model against the experimental data gives physically meaningful parameter estimates; these parameters and the model provide a design equation for the porous electrode current as a function of specific surface area, bulk Br2 concentration, average total overpotential, and the Reynolds number. The design equation shows that the back fed electrode could reduce the loss of Br2 across the separator and the ohmic loss in …

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Modal Control Of An Unstable Periodic Orbit, William Wiesel, William Shelton Jan 1983

Modal Control Of An Unstable Periodic Orbit, William Wiesel, William Shelton

Faculty Publications

We apply Floquet theory to the problem of designing a control system for a satellite in an unstable periodic orbit. Expansion about a periodic orbit produces a time periodic linear system, which is augmented by a time periodic control term. We show that this can be done such that a) the application of control produces only inertial accelerations, b) positive real Poincare exponents are shifted into the left half-plane, and c) the shift of the exponent is linear with control gain. We apply these developments to an unstable orbit near the Earth-Moon L3 point perturbed by the Sun. Finally, …

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The Diffusion Thermoeffect In Ternary, Nonelectrolyte Liquid Mixtures, Richard L. Rowley, Gerald Platt, Tevin Vongvanich Aug 1982

The Diffusion Thermoeffect In Ternary, Nonelectrolyte Liquid Mixtures, Richard L. Rowley, Gerald Platt, Tevin Vongvanich

Faculty Publications

Expressions for that portion of the heat flux which is due to composition gradients in multicomponent nonelectrolyte liquid mixtures have been formulated in terms of heats of transport. The resultant thermal energy equation in combination with component mass balance equations constitute coupled partial differential equations descriptive of the diffusion thermoeffect in liquid mixtures. These equations were solved with a double perturbation technique subject to initial and boundary conditions consistent with experimental design conditions considered appropriate for successful measurement of multicomponent heats of transport. Based on the adiabatic type cell, the expected temperature response, dependent on cell variables, experimental conditions, and …

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Diffusion Thermoeffect Measurements Of Heats Of Transport In Ternary Liquid Toluene Chlorobenzene Bromobenzene Mixtures At 25°C And 3°C, Richard L. Rowley, Gerald Platt, Tevin Vongvanich Aug 1982

Diffusion Thermoeffect Measurements Of Heats Of Transport In Ternary Liquid Toluene Chlorobenzene Bromobenzene Mixtures At 25°C And 3°C, Richard L. Rowley, Gerald Platt, Tevin Vongvanich

Faculty Publications

Heats of transport in ternary nonelectrolyte liquid mixtures have been directly measured for the first time. Diffusion thermoeffect measurements have been made for ternary mixtures of toluene-chlorobenzene-bromobenzene at 25 degrees and 35 degrees C. A new boundary sharpening technique was used in addition to a liquid gate withdrawal method. Both techniques yield consistent, accurate values of the heat of transport, but the new cell provides versatility in allowable densities and compositions of the initial phases. Heats of transport were obtained by nonlinear least-squares fitting of calculated to experimental temperature differences measured at positions symmetric about the initial diffusional interface. The …

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A Unique Microprocessor Instruction Set, D. A. Fairclough May 1982

A Unique Microprocessor Instruction Set, D. A. Fairclough

Faculty Publications

New instruction sets have been based on traditather than on the application of scientific method. Here, the latter has yielded a simple, optimal, en-member instruction set.

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Multiple Scattering Of Protons And Deuterons By Thick Foils, D. R. Dixon, G. L. Jensen, S. M. Morrill, C. J. Connors, R. L. Walter, C. R. Gould, P. M. Thambiduria Apr 1981

Multiple Scattering Of Protons And Deuterons By Thick Foils, D. R. Dixon, G. L. Jensen, S. M. Morrill, C. J. Connors, R. L. Walter, C. R. Gould, P. M. Thambiduria

Faculty Publications

Protons and deuterons from the Triangle Universities Nuclear Laboratory (TUNL) tandem Van de Graaff of energies 3.0, 4.0, and 5.0 MeV were scattered from foils of Al, Ni, Mo, and Ta having thicknesses of 6.14 to 47 mg/cm2. Multiple scattering angular distributions were measured using a position-sensitive detector to collect data at nine different angles simultaneously. Gaussian curves were fitted to the central points of the distributions and the Θ1/e angles thus derived are presented graphically. The data points are compared with calculations using a common method of determining multiple scattering angles. An empirical correction for extending this method into …

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Proton Induced X-Ray Emission Analysis - A Complement To Analytical Methods Used In Environmental Studies, N. F. Mangelson, D. J. Eatough, N. L. Eatough, L. D. Hansen, M. W. Hill, M. L. Lee, L. R. Phillips, M. E. Post, B. E. Richter, J. F. Ryder Apr 1981

Proton Induced X-Ray Emission Analysis - A Complement To Analytical Methods Used In Environmental Studies, N. F. Mangelson, D. J. Eatough, N. L. Eatough, L. D. Hansen, M. W. Hill, M. L. Lee, L. R. Phillips, M. E. Post, B. E. Richter, J. F. Ryder

Faculty Publications

Particle induced X-ray emission (PIXE) analysis is a highly versatile method of element analysis. Thus it is well suited for use as a complement to other methods of analysis in experimental programs requiring both chemical and elemental analyses. This paper reports some results of two projects where PIXE was used in conjunction with titration calorimetry, ion chromatography, atomic absorption spectroscopy, gas chromatography/mass spectrometry, X-ray fluorescence spectroscopy and some other methods. The first is a study of sulfur chemistry in a copper smelter plume. Arsenic was found to be a conservative tracer of the plume and was used for calculation of …

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Effect Of Backup Roll Length And Roll Neck Length On Profile For 4-H Mills, T. Ohto, Guna S. Selvaduray Mar 1981

Effect Of Backup Roll Length And Roll Neck Length On Profile For 4-H Mills, T. Ohto, Guna S. Selvaduray

Faculty Publications

No abstract provided.

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Model For Coal-Fired Reactors, Philip J. Smith, Thomas H. Fletcher, L. Douglas Smoot Jan 1981

Model For Coal-Fired Reactors, Philip J. Smith, Thomas H. Fletcher, L. Douglas Smoot

Faculty Publications

An axisymmetric, elliptic model has been developed for analysis of confined, turbulent coal-laden diffusion flames. The scheme is Eulerian for gases and Lagrangian for particles. The approach emphasizes the turbulent fluid mechanics of the mixing-limited gas phase reaction processes. The two-equation (k-─ e) turbulence model is used for closure. Particle drag and turbulent particle diffusion are also modeled. Gaseous combustion is modeled with a probability density function for the mixture fraction. Fluctuations in mixing of inlet streams and coal off-gas are considered. Coal pyrolysis and oxidation reaction processes are assumed to be slow with respect to the turbulent time scale. …

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The Dufour Effect. Iii. Direct Experimental Determination Of The Heat Of Transport Of Carbon Tetrachloride-Cyclohexane Liquid Mixtures, Richard L. Rowley, Frederick H. Horne Jan 1980

The Dufour Effect. Iii. Direct Experimental Determination Of The Heat Of Transport Of Carbon Tetrachloride-Cyclohexane Liquid Mixtures, Richard L. Rowley, Frederick H. Horne

Faculty Publications

The heat of transport of carbon tetrachloride-cyclohexane liquid mixtures has been determined directly by Dufour effect experiments. The technique employs a withdrawable ''liquid gate'' to create a nonturbulent, sharp diffusional interface. The partial differential equations governing the barycentric velocity, composition, and temperature distributions are solved with a Crank-Nicholson implicit numerical scheme. This allows inclusion of the composition and temperature dependence of the thermodynamic and transport parameters. For mean mole fraction of carbon tetrachloride x1 between 0.34 and 0.55 and for mean temperature T between 295.13 and 296.43 degreesK, the best least squares fit of the data for the heat of …

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Proliferation Resistant Reprocessing Methods, Guna S. Selvaduray, L. Heising Nov 1979

Proliferation Resistant Reprocessing Methods, Guna S. Selvaduray, L. Heising

Faculty Publications

No abstract provided.

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Finding A Site To Store Spent Fuel In The Pacific Basin, Guna S. Selvaduray, M. Goldstein, R. N. Anderson Sep 1979

Finding A Site To Store Spent Fuel In The Pacific Basin, Guna S. Selvaduray, M. Goldstein, R. N. Anderson

Faculty Publications

No abstract provided.

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Separation Technologies Reviewed, Guna S. Selvaduray, R. N. Anderson, M. Goldstein Aug 1978

Separation Technologies Reviewed, Guna S. Selvaduray, R. N. Anderson, M. Goldstein

Faculty Publications

No abstract provided.

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The Dufour Effect. Ii. Experimental Confirmation Of The Onsager Heat-Mass Reciprocal Relation For A Binary Liquid Mixture, Richard L. Rowley, Frederick H. Horne Jan 1978

The Dufour Effect. Ii. Experimental Confirmation Of The Onsager Heat-Mass Reciprocal Relation For A Binary Liquid Mixture, Richard L. Rowley, Frederick H. Horne

Faculty Publications

Although experimental verification of Onsager's reciprocal relations has been achieved in a variety of cases, no quantitative test of the heat-mass reciprocal relation for a binary liquid system has previously been reported. We present in this communication experimental proof of the equality of the mass-heat reciprocal relation for the system carbon tetrachloride - cyclohezane.

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Atomic Simulation Of The Al2 (111) (110) Edge Dislocation In Alpha-Iron, Brent L. Adams, P. C. Gehlen, J. P. Hirth, R. G. Hoagland Apr 1977

Atomic Simulation Of The Al2 (111) (110) Edge Dislocation In Alpha-Iron, Brent L. Adams, P. C. Gehlen, J. P. Hirth, R. G. Hoagland

Faculty Publications

The authors are pleased to acknowledge: the support of this research by the National Science Foundation under Grant DMR 74-21243 and by the provision of computer time by The Ohio State University and by Battelle Columbus Laboratories; and helpful comments on the manuscript by V Vitek. Computer simulation is used to obtain the plane strain and non-plane strain equilibrium core structures for the a/2 <111> {110} edge dislocation in alpha-iron as modelled by the Johnson potential. The methods of the integral formulation of anisotropic linear eleasticity theory are employed in the analysis. Flexible core boundary methods reveal that positive volume expansions …

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Potential-Selective Deposition Of Copper From Chloride Solutions Containing Iron, Ralph E. White, James A. Trainham, John Newman, Thomas W. Chapman Jan 1977

Potential-Selective Deposition Of Copper From Chloride Solutions Containing Iron, Ralph E. White, James A. Trainham, John Newman, Thomas W. Chapman

Faculty Publications

The hydrometallurgy of copper may involve leaching of the metal from its ore with an aqueous solution containing cupric and ferric chloride. The subsequent deposition of copper from such a process stream is modeled here in an idealized electrochemical cell with a rotating-disk electrode. The potential distribution and concentration profiles within the diffusion layer are predicted for given potential differences between the electrode and the solution. The cuprous ion, which is formed by the reduction of the complexed cupric ion at the electrode, is stabilized in the chloride solution and can react either at the electrode or with ferric species …

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Two Preliminary Studies Of The Intelligibility Of Predictor-Coefficient And Formant-Coded Speech, L. Keeler, G. Clement, W. Strong, E. Palmer Oct 1976

Two Preliminary Studies Of The Intelligibility Of Predictor-Coefficient And Formant-Coded Speech, L. Keeler, G. Clement, W. Strong, E. Palmer

Faculty Publications

Two preliminary studies comparing the intelligibilities of predictor-coefficient versus formant-frequency-coded speech and the intelligibilities of predictor-coefficient-coded speech using different numbers of coefficients are reported.

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The Topolotron: A High Beta Device With Topological Stability, Keith H. Brown, H. R. P. Ferguson, J. H. Gardner, Larry V. Knight, H. Mark Nelson Sep 1976

The Topolotron: A High Beta Device With Topological Stability, Keith H. Brown, H. R. P. Ferguson, J. H. Gardner, Larry V. Knight, H. Mark Nelson

Faculty Publications

The concept of topological or structural stability is introduced and its importance in the magnetic confinement of plasmas is discussed. Topological stability requires the presence of a pair of limit cycles in the magnetic field configuration. This paper deals with the design of an experimental device possessing limit cycles. The design includes a high beta (b=1), high density (10^16), hot (100 eV) hydrogen plasma which is to be compressed by a factor of about 5 in a torodial device of 25 cm average major radius with a capacitor bank rise time of less than 2 µsec. Two shaped toroidal coils …

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