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1991

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Articles 1291 - 1320 of 1362

Full-Text Articles in Engineering

Nebraska Summary: S102 Ford 3430 8x8, Nebraska Tractor Test Lab Jan 1991

Nebraska Summary: S102 Ford 3430 8x8, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Nebraska Summary: S101 John Deere 3255, Nebraska Tractor Test Lab Jan 1991

Nebraska Summary: S101 John Deere 3255, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Nebraska Summary: S137 Zetor 9540, Nebraska Tractor Test Lab Jan 1991

Nebraska Summary: S137 Zetor 9540, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Nebraska Summary: S338 Hurlimann 6135, Nebraska Tractor Test Lab Jan 1991

Nebraska Summary: S338 Hurlimann 6135, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …


Unreachable Roots For Global Homotopy Continuation Methods, Soo Hyoung Choi, Neil L. Book Jan 1991

Unreachable Roots For Global Homotopy Continuation Methods, Soo Hyoung Choi, Neil L. Book

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.


An Unsolicited Sociotechnical Intervention In A Public System: A Participatory Action Research Approach, Ely Alfred Dorsey Jr. Jan 1991

An Unsolicited Sociotechnical Intervention In A Public System: A Participatory Action Research Approach, Ely Alfred Dorsey Jr.

Engineering Management & Systems Engineering Theses & Dissertations

This research concerns itself with Participatory Action Research in a hostile setting. The thrust is a sociotechnical one, with the intent being to enhance the capacity of the Wallop Public School System, Wallop, USA, to address its problem of racial disparate treatment of Black children. The potential for Organizational Learning among the school system's senior staff is studied. Some new theory about such hostile interventions is proposed. Also discussed are questions about reliability and construct validity within the context of the multiple role playing that an interventionist has in this setting. The role of the press is reflected in the …


Impact On Laminated Composite Materials, Serge Abrate Jan 1991

Impact On Laminated Composite Materials, Serge Abrate

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laminated composite materials are used extensively in aerospace and other applications. With their high specific modulus, high specific strength, and the capability of being tailored for a specific application, these materials offer definite advantages compared to more traditional materials. However, their behavior under impact is a concern, since impacts do occur during manufacture, normal operations, or maintenance. The situation is critical for impacts which induce significant internal damage, undetectable by visual inspection, that cause large drops in the strength and stability of the structure. Impact dynamics, including the motion of both the impactor and the target and the force developed …


Narrow-Winged Seeder Points Reduce Water Erosion And Maintain Crop Yields, Kevin Bligh Jan 1991

Narrow-Winged Seeder Points Reduce Water Erosion And Maintain Crop Yields, Kevin Bligh

Journal of the Department of Agriculture, Western Australia, Series 4

Sowing crops without loosening the topsoil by tillage reduces water erosion. It can increase infiltration of rainfall into loamy soils, thereby reducing runoff and increasing potential crop yields. Crop yields were maintained after I1 seasons of seeding an Avon Valley loam near Beverley with minimum and no-tillage seeding operations. Infiltration increased significantly from 80 per cent of the 1983 growing-season rainfall under the traditional three tillage operations, to 87per cent under a single tillage operation using a combine seed drill. Infiltration increased further to 96 per cent under a no-tillage system using a triple^lisc drill. At Gnowangerup, 80 per cent …


Novel Chemical Preparative Route For Semiconducting Mose2 Thin Films, K. C. Mandal, O. Savadogo Jan 1991

Novel Chemical Preparative Route For Semiconducting Mose2 Thin Films, K. C. Mandal, O. Savadogo

Faculty Publications

No abstract provided.


Performance Of Seedigated And Conventionally Planted Crops, W. S. Leander Jr., Derrel L. Martin, James R. Gilley Jan 1991

Performance Of Seedigated And Conventionally Planted Crops, W. S. Leander Jr., Derrel L. Martin, James R. Gilley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Seedigation is the use of a moving sprinkler irrigation system to broadcast seeds on the soil surface. Seed germination, plant characteristics and yield for grain sorghum, winter wheat and soybeans that were seedigated and conventionally planted are compared. When the seeding rates for seedigation were increased above that for conventional planting, and adequate moisture was available for germination, grain sorghum and wheat seedigated on tilled surfaces produced yields similar to conventionally planted crops. Seedigation of soybeans into fallow conditions, or when used as a relay crop, was unsuccessful. Shallow disking following seedigation did not improve germination or yield of grain …


Residue Management To Control Soil Erosion By Water, Elbert C. Dickey, David P. Shelton, Paul J. Jasa, Michael C. Hirschi Jan 1991

Residue Management To Control Soil Erosion By Water, Elbert C. Dickey, David P. Shelton, Paul J. Jasa, Michael C. Hirschi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The Erosion Process

Erosion of topsoil begins when water detaches individual soil particles from clod and other soil aggregates. A single raindrop may seem insignificant, yet collectively, raindrops strike the ground with surprising force. During an intense storm, rainfall can loosen and detach up to 100 tons of soil per acre and can be especially erosive when residue mulch or vegetation are not present to absorb their impact.

Two problems often occur during rainstorms. The rate of rainfall can exceed the rate at which water can enter the soil and raindrop impact forces can partially seal the soil surface. In …


A Mathematical Model Of Electrochemical Reactions Coupled With Homogeneous Chemical Reactions, Ken-Ming Yen, Taewhan Yeu, Ralph E. White Jan 1991

A Mathematical Model Of Electrochemical Reactions Coupled With Homogeneous Chemical Reactions, Ken-Ming Yen, Taewhan Yeu, Ralph E. White

Faculty Publications

The zinc/bromine (Zn/Br2) flow battery has received considerable
attention in recent years [e.g., (2-4)]. Although it
is agreed that the solution chemistry is important in the
system, most of the work that has been done is concentrated
on the design variables. In this note the basic mass
transfer-solution and surface kinetics are studied to furnish
a better understanding of the system.


Current Distribution In A Horizon® Lead-Acid Battery During Discharge, Z. Mao, Ralph E. White, B. Jay Jan 1991

Current Distribution In A Horizon® Lead-Acid Battery During Discharge, Z. Mao, Ralph E. White, B. Jay

Faculty Publications

A simple mathematical model is presented and used to analyze the potential and current distributions in a HORIZON® sealed lead-acid battery. It was found that an increase in the thickness of an electrode would not enhance the discharge rate of that electrode; instead, it causes the transfer current distribution to be less uniform in the electrode. Also, the ohmic drop across the separator would decrease with a decrease in the thickness of the separator more rapidly when the thickness is small than when it is large. In addition, it was found that efficient high-capacity, high-rate electrodes must consider the electrode …


Impedance Analysis For Oxygen Reduction In A Lithium Carbonate Melt, Bhasker B. Davé, Ralph E. White, Supramaniam Srinivasan, A. John Appleby Jan 1991

Impedance Analysis For Oxygen Reduction In A Lithium Carbonate Melt, Bhasker B. Davé, Ralph E. White, Supramaniam Srinivasan, A. John Appleby

Faculty Publications

Oxygen reduction on a smooth gold electrode in a pure lithium carbonate melt was investigated by electrochemical impedance spectroscopy and cyclic voltammetry. The impedance data were analyzed using the Randles-Ershler equivalent circuit to determine parameters such as the charge-transfer resistance, Warburg coefficient, double-layer capacity, and uncompensated electrolyte resistance. The parameters estimated by complex plane plots and a complex nonlinear least squares method are in good agreement. Cyclic voltammetric measurements showed that oxygen reduction in a lithium carbonate melt is very rapid. A mass transfer parameter, DC0, estimated by the cyclic voltammetry concurred withthat calculated by the electrochemical …


Electrochemical Characterization Of Electronically Conductive Polypyrrole On Cyclic Voltammograms, Taewhan Yeu, Ken-Ming Yin, Jose Carbajal, Ralph E. White Jan 1991

Electrochemical Characterization Of Electronically Conductive Polypyrrole On Cyclic Voltammograms, Taewhan Yeu, Ken-Ming Yin, Jose Carbajal, Ralph E. White

Faculty Publications

Experimental and theoretical cyclic voltammograms for electronically conducting polypyrrole film are obtained from the identical conditions and compared to each other to characterize electrochemical behavior of the polymer. A comparison of the simulated and experimental cyclic yoltammograms shows quantitative agreement. The profiles of the dependent variables show that the switching process is governed by the availability of the counter ion to the polypyrrole electrode and the amount of electroactive sites. Sensitivity analysis shows that the double layer effects have more influence in the cyclic voltammograms than the electrokinetic effects.


A Modified Electrochemical Process For The Decomposition Of Hydrogen Sulfide In An Aqueous Alkaline Solution, Z. Mao, A. Anani, Ralph E. White, S. Srinivasan, A. J. Appleby Jan 1991

A Modified Electrochemical Process For The Decomposition Of Hydrogen Sulfide In An Aqueous Alkaline Solution, Z. Mao, A. Anani, Ralph E. White, S. Srinivasan, A. J. Appleby

Faculty Publications

An electrochemical process for the decomposition of hydrogen sulfide into its constituents in an aqueous alkaline solution is presented. It essentially consists of presaturation of an alkaline scrubber solution with H2S. Thereafter, partial neutralization of the presaturated solution provides not only the necessary mass balance for electrolysis, but also creates the optimum conditions under which passivation of the anode, as well as side chemical and electrochemical reactions, are minimized. Finally, the electrolysis stage of the process leads to precipitation of crystalline sulfur at the anode and evolution of hydrogen at the cathode. Regeneration of the alkaline solution via …


A Mathematical Model Of The Self-Discharge Of A Ni-H2 Battery, Z. Mao, Ralph E. White Jan 1991

A Mathematical Model Of The Self-Discharge Of A Ni-H2 Battery, Z. Mao, Ralph E. White

Faculty Publications

A simple mathematical model is presented and used to characterize the self-discharge of a nickel oxyhydroxide(NiOOH) electrode in a hydrogen environment. This model includes diffusion of dissolved hydrogen in an electrolyte film which covers a flooded electrode, electrochemical oxidation of hydrogen, reduction of nickel oxyhydroxide, and changes of surface area and of porosity of the electrode during the self-discharge process. Although the self-discharge process is complicated, the predictions of the model are consistent with experimental results reported in the literature, which include linear relationships between the logarithm of hydrogen pressure and time and between the logarithm of the capacity remaining …


In Situ Degradation Of Polyhalogenated Aromatic Hydrocarbons By Electrochemically Generated Superoxide Ions, E. E. Kalu, Ralph E. White Jan 1991

In Situ Degradation Of Polyhalogenated Aromatic Hydrocarbons By Electrochemically Generated Superoxide Ions, E. E. Kalu, Ralph E. White

Faculty Publications

The reduction of dioxygen in aprotic media yields superoxide ions which react with polyhalogenated aromatic hydrocarbons by nucleophilic substitution. The degradation of hexachlorobenzene to bicarbonates and chlorides using in situ generated superoxide ions was carried out at room temperature in a flow cell system equipped with a gas fed, porous electrode. The effects of current, electrolyte flow, and aprotic media on the extent of degradation of hexachlorobenzene are presented.


A Mathematical Model Of A Hydrogen/Oxygen Alkaline Fuel Cell, Michael C. Kimble, Ralph E. White Jan 1991

A Mathematical Model Of A Hydrogen/Oxygen Alkaline Fuel Cell, Michael C. Kimble, Ralph E. White

Faculty Publications

A mathematical model of a hydrogen/oxygen alkaline fuel cell is presented that can be used to predict polarization behavior under various potential loads. The model describes the phenomena occurring in the solid, liquid, and gaseous phases of the anode, separator, and cathode regions, assuming a macrohomogeneous, three-phase porous electrode structure. The model calculates the spatial variation of the partial pressures of oxygen, hydrogen, and water vapor, dissolved oxygen and hydrogen concentrations, electrolyte concentration, and the solid- and solution-phase potential drops. By developing a complete model of the alkaline fuel cell, the interaction of the various transport and kinetic resistances can …


Mathematical Modeling Of A Nickel-Cadmium Battery: Effects Of Intercalation And Oxygen Reactions, Deyuan Fan, Ralph E. White Jan 1991

Mathematical Modeling Of A Nickel-Cadmium Battery: Effects Of Intercalation And Oxygen Reactions, Deyuan Fan, Ralph E. White

Faculty Publications

Extensions are presented for a previously published (1) mathematical model of a nickel-cadmium (Ni-Cd) cell. These extensions consist of intercalation thermodynamics for the nickel electrode and oxygen generation and reduction reactions during charge and overcharge. The simulated results indicate that intercalation may be important in the nickel electrode and that including the oxygen reactions provides a means of predicting the efficiency of the cell on charge and discharge.


Effect Of Ohmic, Mass-Transfer, And Kinetic Resistances On Linear-Sweep Voltammetry In A Cylindrical-Pore Electrode, John W. Weidner, Peter S. Fedkiw Jan 1991

Effect Of Ohmic, Mass-Transfer, And Kinetic Resistances On Linear-Sweep Voltammetry In A Cylindrical-Pore Electrode, John W. Weidner, Peter S. Fedkiw

Faculty Publications

Extracting quantitative kinetic information from linear-sweep voltammograms (LSV) on porous electrodes is more difficult than on planar electrodes since the electrode surface is not uniformly accessible to the bulk supply of reactant or the counterelectrode. We present here a means to account for the effect of ohmic, mass-transfer, and kinetic resistances on LSV by modeling a pore in a porous matrix as a cylindrical-pore electrode, and solving the mass and charge conservation equations in the context of this geometry for the simply redox reaction O + ne– <=> R where both O and R are soluble species. Both analytical …


A Mathematical Model For Outgassing And Contamination, W. Fang, M. Shillor, E. Stahel, E. Epstein, C. Ly, J. Mcniel, Edward D. Zaron Jan 1991

A Mathematical Model For Outgassing And Contamination, W. Fang, M. Shillor, E. Stahel, E. Epstein, C. Ly, J. Mcniel, Edward D. Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

A model for the mathematical description of the processes of outgassing and contamination in a vacuum system is proposed. The underlying assumptions are diffusion in the source, convection and diffusion in the cavity, mass transfer across the source-cavity interface, and a generalization of the Langmuir isotherm for the sorption kinetics on the target. Three approximations are considered where the asymptotic behavior of the model for large time is shown as well as the dependence and sensitivity of the model on some of the parameters. Some numerical examples of the full model are then presented together with a proof of the …


Sectar: Model For Economically Optimal Sustained Groundwater Yield Planning, Richard C. Peralta, K. Asghari, R. N. Shulstad Jan 1991

Sectar: Model For Economically Optimal Sustained Groundwater Yield Planning, Richard C. Peralta, K. Asghari, R. N. Shulstad

Civil and Environmental Engineering Faculty Publications

This paper presents an approach for computing economically optimal sustained yield ground-water extract ion strategies and supportable irrigated crop acreages. Computed regional strategies maximize the present value of net economic return_ They are useful for long-term agricultural planning because they are sustainable even beyond the planning period considered within the economic optimization. The hybrid approach uses only steady-state flow equations and iterative simulation/optimization to reduce optimization memory requirements below that required by conventional models utilizing both steady and unsteady equations. SECTAR, a quadratic optimization planning model assumes heads will evolve toward optimal steady-state but does initially not know the nonlinear …


Assessing Pesticide Contamination To Groundwater: A Rapid Approach, Majid Ehteshami, Richard C. Peralta, Hubert Eisele, Howard M. Deer, Terry Tindall Jan 1991

Assessing Pesticide Contamination To Groundwater: A Rapid Approach, Majid Ehteshami, Richard C. Peralta, Hubert Eisele, Howard M. Deer, Terry Tindall

Civil and Environmental Engineering Faculty Publications

A methodology has been developed for identifying hazardous pesticides/site combinations threatening ground-water contamination. Screening methodologies are required to determine which locations and pesticides now in use should receive the greatest attention to safeguard the public health. The presented method uses a hazard to ground-water hydrogeological screening model (DRASTIC) and employs a one-dimensional pesticide transport model ( CMLS). The method is an efficient and practical technique to identify where particular combinations of pesticides, water management practices, soils, and geology result in the greatest potential hazard to ground-water contamination. Use of the presented approach can reduce sampling needs and expense.


User's Manual For The Software "Tfpi" That Implements The Traffic Forecasting Procedure For Indiana, Sunil K. Saha, Jon D. Fricker Jan 1991

User's Manual For The Software "Tfpi" That Implements The Traffic Forecasting Procedure For Indiana, Sunil K. Saha, Jon D. Fricker

JTRP Technical Reports

A program has been written in Microsoft QuickBASIC to implement the traffic models developed for both rural and urban Indiana state highway segments during a two-phase HPR Project carried out for the Indiana Department of Transportation. The report ''TRAFFIC VOLUME FORECASTING METHODS FOR RURAL STATE HIGHWAYS" describes the models developed in Phase 1 of the study, while the report "THE DEVELOPMENT OF A PROCEDURE TO FORECAST TRAFFIC VOLUMES ON URBAN SEGMENTS OF THE STATE AND INTERSTATE HIGHWAY SYSTEMS" describes the models developed in Phase 2. For rural interstates, new models have been developed in Phase 2 that supercede the Phase …


Use Of Waste Materials In Highway Construction, Imtiaz Ahmed Jan 1991

Use Of Waste Materials In Highway Construction, Imtiaz Ahmed

JTRP Technical Reports

This study synthesizes the information on the use of waste materials in highway construction. The information was obtained from a review of published literature supplemented by: recent unpublished reports, presentations of research updates by professionals at different forums, anti personal meetings with the experts. In addition, a questionnaire regarding the use of waste materials was prepared and distributed to each of the state highway agencies. A majority of states responded to the questionnaire, giving a summary of current practices in the use of waste materials in highway construction and their experiences on the technical, environmental, and economic aspects of the …


Lrfd Cold-Formed Steel Design Manual, American Iron And Steel Institute Jan 1991

Lrfd Cold-Formed Steel Design Manual, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.


Methods Of Measuring The Solubility And Viscosity Of Lubricating Oil/Refrigerant Mixtures At High Discharge Pressures And Temperatures, Nolan Van Gaalen Jan 1991

Methods Of Measuring The Solubility And Viscosity Of Lubricating Oil/Refrigerant Mixtures At High Discharge Pressures And Temperatures, Nolan Van Gaalen

Faculty Work Comprehensive List

The design and construction of a test facility and methodology for measuring the solubility and viscosity of lubricating oil/refrigerant mixtures at high pressures and temperatures are described. An auxiliary charging system, developed to provide precisely measured quantities of oil and refrigerant to the test facility, is also presented. The test facility was developed under the sponsorship and supervision of ASHRAE which funded this research project (RP-580);The solubility, viscosity and density of mixtures of R-22 and of R-502 with commonly used 150 SUS lubricants have been measured by using this facility. Specifically, results for liquid mixtures of 10% to 40% refrigerant …


Perceived Importance Of Identified Duties And Tasks In The Area Of Design/Drafting Management, John Edward Shultz Jan 1991

Perceived Importance Of Identified Duties And Tasks In The Area Of Design/Drafting Management, John Edward Shultz

Dissertations and Theses @ UNI

The purpose of the study, was to determine the importance of identified duties to the career success of a newly hired design/drafting employee aspiring to become a supervisor or manager as perceived by design/drafting managers and university professors. An opinionnaire was developed which consisted of 141 tasks which were grouped into 13 general duties. The 13 duties represented the job functions for design/drafting managers. The opinionnaire was validated utilizing a jury of experts consisting of eight design/drafting managers and five university professors. It was then mailed to the membership of the American Design Drafting Association (ADDA) who identified themselves as …


Factors Influencing Preparation Needed Of Future Industrial Technology Department Leaders In Higher Education, Rajendra L. Desai Jan 1991

Factors Influencing Preparation Needed Of Future Industrial Technology Department Leaders In Higher Education, Rajendra L. Desai

Dissertations and Theses @ UNI

The object of this study was to help future industrial technology department leaders in higher education develop effective planning strategies and prioritize their preparation before they sought leadership positions in industrial technology. Two hundred fifty-four industrial technology department leaders in higher education from all over the United States were asked to respond to a questionnaire. A five point Likert-type scale was used to rate the importance of 58 statements identified from Marshall's (1984) study. One hundred sixty (62.99%) usable responses formed the basis of this study.

Mean values and standard deviations were determined for all the statements. The grand mean …