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Articles 173371 - 173400 of 198025

Full-Text Articles in Engineering

Nebraska Summary: S257 Case-Ih Mx 110, Nebraska Tractor Test Lab Jan 1997

Nebraska Summary: S257 Case-Ih Mx 110, 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: S254 Caterpillar Challenger 55, Nebraska Tractor Test Lab Jan 1997

Nebraska Summary: S254 Caterpillar Challenger 55, 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: S303 Massey Ferguson 6270, Nebraska Tractor Test Lab Jan 1997

Nebraska Summary: S303 Massey Ferguson 6270, 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 …


Sensitivities Of Report Writing For Weak-Rock Projects, Allen W. Hatheway Jan 1997

Sensitivities Of Report Writing For Weak-Rock Projects, Allen W. Hatheway

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Weak rock is the natural realm of geological engineers and engineering geologists. We are the best equipped geotechnical professionals to deal effectively with these difficult and generally complex earth materials, and we have the obligation to produce the most informative technical reports possible in weak-rock assignments. Because of the strength-related problems of weak rock, we should remain cognizant of the need to emphasize several aspects of our reports. For this purpose weak rock occurs because of one or more strength-degrading considerations: 1. Weak to deleterious lithology; the latter imparting damaging characteristics to concretes and to rock utilized as rip-rap and …


Relative Permeability Effects On The Migration Of Steamflood Saturation Fronts, A. Erkal, Daopu Thompson Numbere Jan 1997

Relative Permeability Effects On The Migration Of Steamflood Saturation Fronts, A. Erkal, Daopu Thompson Numbere

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The effects of various relative permeability-saturation relationships on the movement of water saturation fronts during steam flooding is investigated. Empirical correlations, curve fitting and spline interpolation functions are used to represent the relative permeability data. The effects of these correlations on water saturation movement and ultimately on oil recovery performance are compared. It was observed that only the spline function is able to adequately represent a given set of data throughout its saturation range. All the other correlations fit the given data well only at high water saturations and fit poorly at the low saturations. Furthermore, the correlations converge at …


Evaluation Of Unified Interaction Parameter Model Parameters For Calculating Activities Of Ferromanganese Alloys: Mn-Fe-C, Mn-Fe-Si, Mn-C-Si, And Mn-Fe-C-Si Systems, L. I. Hongjie, Arthur E. Morris Jan 1997

Evaluation Of Unified Interaction Parameter Model Parameters For Calculating Activities Of Ferromanganese Alloys: Mn-Fe-C, Mn-Fe-Si, Mn-C-Si, And Mn-Fe-C-Si Systems, L. I. Hongjie, Arthur E. Morris

Materials Science and Engineering Faculty Research & Creative Works

Interaction parameters for Mn-based alloys were evaluated using both carbon solubility and activity data for species in binary and ternary manganese alloys. The parameters at 1400 °C are the following εcc = -4.5; εccc = 58.8; εFeCC = 1.5; εFeCC = 2.5; In γC0 = -1.15 . εsisi = 15.5; εsisisi = 2.69; εFeSi = 2.5; εcsi = 12.4; εccsi = 27.5; In γSi0 = -7.46 The unified interaction parameter model (UIPM) was used to calculate the activity coefficients of species and the solubility of carbon in ferromanganese alloys (up to quaternary Mn-Fe-C-Si). The results were in good agreement with …


Limitations And Dynamics Imposed On Multicomponent Batch Distillation By Tray Hydraulics, Keith G. Tomazi Jan 1997

Limitations And Dynamics Imposed On Multicomponent Batch Distillation By Tray Hydraulics, Keith G. Tomazi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Batch distillation models incorporating a complete set of hydraulic relations, energy balances, and tray efficiencies and simpler models based upon constant molar holdup and zero holdup (the Rayleigh equation) were used to obtain distillation curves and optimal reflux policies. The approach to hydraulic limitations was monitored in the complete hydraulic model. The results indicate that during a multicomponent batch distillation the combination of the changes in the liquid composition and liquid flow rates causes the molar holdup on the trays to vary with time and, consequently, the characteristic time constant of the trays changes. The predicted composition profiles for descriptions …


High-Pressure Trickle-Bed Reactors: A Review, Muthanna H. Al-Dahhan, Faical Larachi, Milorad P. Dudukovic, Andre Laurent Jan 1997

High-Pressure Trickle-Bed Reactors: A Review, Muthanna H. Al-Dahhan, Faical Larachi, Milorad P. Dudukovic, Andre Laurent

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Concise Review of Relevant Experimental Observations and Modeling of High-Pressure Trickle-Bed Reactors, based on Recent Studies, is Presented. the Following Topics Are Considered: Flow Regime Transitions, Pressure Drop, Liquid Holdup, Gas-Liquid Interfacial Area and Mass-Transfer Coefficient, Catalyst Wetting Efficiency, Catalyst Dilution with Inert Fines, and Evaluation of Trickle-Bed Models for Liquid-Limited and Gas-Limited Reactions. the Effects of High-Pressure Operation, Which is of Industrial Relevance, on the Physicochemical and Fluid Dynamic Parameters Are Discussed. Empirical and Theoretical Models Developed to Account for the Effect of High Pressure on the Various Parameters and Phenomena Pertinent to the Topics Discussed Are Briefly …


The Effects Of Human-Computer Communication Mode, Task Complexity, And Desire For Control On Performance And Discourse Organization In An Adaptive Task, Cristina Bubb-Lewis Jan 1997

The Effects Of Human-Computer Communication Mode, Task Complexity, And Desire For Control On Performance And Discourse Organization In An Adaptive Task, Cristina Bubb-Lewis

Psychology Theses & Dissertations

The present study examined how different communication patterns affected task performance with an adaptive interface. A Wizard-of-Oz simulation (Gould, Conti, & Hovanyecz, 1983) was used to create the impression of a talking and listening computer that acted as a teammate to help participants interact with a computer application.

Four levels of communication mode were used which differed in the level of restriction placed on human-computer communication. In addition, participants completed two sets of tasks (simple and complex). Further, a personality trait, Desire for Control (DC), was measured and participants were split into high and low groups for analysis. Dependent measures …


Integrating Design Into The Sophomore And Junior Level Mechanics Courses, Douglas R. Carroll Jan 1997

Integrating Design Into The Sophomore And Junior Level Mechanics Courses, Douglas R. Carroll

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Engineering schools across the country are developing ways of integrating design into their curriculum, and a question that often arises is how to best integrate design into the sophomore and junior level courses. Freshman design projects or mechanical dissection courses are designed to give the students hands-on experience in conceptual design and construction, with little if any of the mathematical modeling normally used in engineering design. The capstone senior design project is a true engineering design experience, where students draw from their background to conceptualize, analyze, model, refine, and optimize a product to meet design, manufacturing, and life cycle cost …


Numerical Simulations Of Full- Scale Corroded Pipe Tests With Combined Loading, Samit Roy, S. Grigory, M. Smith, M. F. Kanninen, M. Anderson Jan 1997

Numerical Simulations Of Full- Scale Corroded Pipe Tests With Combined Loading, Samit Roy, S. Grigory, M. Smith, M. F. Kanninen, M. Anderson

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The ANSI/ASME B31G guideline has been useful to pipeline operators in assessing the integrity of corroded line pipe. Because large safety margins have had to be incorporated, the guidelines can be excessively conservative, which in turn can force costly repairs and replacements that may not actually be necessary. On the other hand, because the current guidelines consider only pressure loading and neglect bending and axial compression, they could give nonconservative failure predictions when combined loading exists. Therefore, a study was initiated to develop a theoretically sound methodology for assessing the integrity of corroded line pipe subjected to combined loading. A …


The Sol Of New Orleans: An Undergraduate Design Experience, Edit J. Kaminsky, Brian L. Hardouin Jan 1997

The Sol Of New Orleans: An Undergraduate Design Experience, Edit J. Kaminsky, Brian L. Hardouin

Electrical Engineering Faculty Publications

This paper presents the incorporation of the design, construction, and testing of a solar-powered car into the undergraduate curriculum of the Electrical Engineering Department of the University of New Orleans. All work on the vehicle is entirely performed by students who earn design credits in our Senior EE Design Project and/or Special Problems in EE courses.


Operation And Control In A Competitive Market: Distributed Generation In A Restructured Industry, Judith Cardell, Richard Tabors Jan 1997

Operation And Control In A Competitive Market: Distributed Generation In A Restructured Industry, Judith Cardell, Richard Tabors

Engineering: Faculty Publications

The prospect of independent ownership for distributed technologies is being encouraged by the current deregulation of the industry, and it is possible that the new generators will be independently operated as well as independently owned. The siting of numerous small-scale generators in distribution feeders is likely to have an impact on the operations and control of the power system, a system designed to operate with large, central generating facilities. In response to the new and potentially conflicting economic and technical demands of a growing number of independent players, the power system may require new means for coordinating system operations. Price …


An Aggregation Procedure For Simulating Manufacturing Flow Line Models, Paul Savory, Gerald Mackulak Jan 1997

An Aggregation Procedure For Simulating Manufacturing Flow Line Models, Paul Savory, Gerald Mackulak

Department of Industrial and Management Systems Engineering: Faculty Publications

We develop a formal method for specifying an aggregate discrete-event simulation model of a production flow line manufacturing system. The methodology operates by aggregating production stations or resources of a flow line. Determining the specifications for representing the aggregated resources in a simulation model is the focus of our presentation. We test the methodology for a set of flow lines with exponentially distributed arrival and service times. Comparisons between analytical and simulation results indicate the aggregation approach is quite accurate for estimating average part cycle time.


Part Form Errors Predicted From Machine Tool Performance Measurements, R. G. Wilhelm, N. Srinivasan, F. Farabaugh, R. Hocken Jan 1997

Part Form Errors Predicted From Machine Tool Performance Measurements, R. G. Wilhelm, N. Srinivasan, F. Farabaugh, R. Hocken

Department of Mechanical and Materials Engineering: Faculty Publications

Machine tool performance testing, as defined by IS0 230 and ANSI B5.54 has been successfully used to maintain and improve the accuracy and repeatability of production-level machine tools. In this study, a controlled series of experiments have been used to test the efficacy of these performance tests in the prediction of part form errors. Results are shown for flatness, squareness, position, and profile tolerances. The experimental results suggest that standard machine tool performance tests can also be used to predict the “best-case” tolerances that can be achieved for particular part features.


Selected Physical Properties Of Jointed Goatgrass (Aegilops Cylindrica Host.), C. M. Hubbard, Curtis L. Weller, David D. Jones Jan 1997

Selected Physical Properties Of Jointed Goatgrass (Aegilops Cylindrica Host.), C. M. Hubbard, Curtis L. Weller, David D. Jones

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Selected physical properties of jointed goatgrass samples collected in western Nebraska and eastern Colorado were determined. Measured properties were spikelet dimensions (length 10.8 ± 0.35 mm; width 2.59 ± 0.25 mm), particle density (0.761 ± 0.016 g/m3), bulk density (351 ± 26.9 kg/m3), terminal velocity (301 ± 25.9 m/min), angle of repose (26.3 ± 0.286°), internal coefficient of friction (0.494 ± 0.007), and equilibrium moisture contents at 10% RH (6.56 ± 1.03% w.b.), 30% RH (7.43 ± 1.21% w.b.), 50% RH (9.01 ± 0.67% w.b.), 70% RH (11.89 ± 0.61% w.b.), and 90% RH (20.39 ± …


Runoff, Erosion, And Soil Quality Characteristics Of A Former Conservation Reserve Program Site, John E. Gilley, John W. Doran, Douglas Karlen, T. C. Kaspar Jan 1997

Runoff, Erosion, And Soil Quality Characteristics Of A Former Conservation Reserve Program Site, John E. Gilley, John W. Doran, Douglas Karlen, T. C. Kaspar

Department of Agricultural and Biological Systems Engineering: Faculty Publications

No-till and moldboard plow tillage systems were established on a former Conservation Reserve Program (CRP) site in southwest Iowa. Runoff rates from simulated rainfall events were significantly greater on sites returned to crop production than from adjoining, undisturbed CRP areas. Substantial soil loss was measured from the moldboard plow treatments, but no significant differences in erosion rates were found between the undisturbed CRP and no-till management systems. No-till management maintained levels of soil quality similar to those of CRP by preserving soil structural integrity and reducing losses of soil organic matter (SOM) associated with tillage. Conservation tillage systems which maintain …


Governing Equations For Transport In Porous Electrodes, Pauline De Vidts, Ralph E. White Jan 1997

Governing Equations For Transport In Porous Electrodes, Pauline De Vidts, Ralph E. White

Faculty Publications

No abstract provided.


An Electrochemical Route For Making Porous Nickel Oxide Electrochemical Capacitors, Venkat Srinivasan, John W. Weidner Jan 1997

An Electrochemical Route For Making Porous Nickel Oxide Electrochemical Capacitors, Venkat Srinivasan, John W. Weidner

Faculty Publications

Porous nickel oxide films were prepared by electrochemically precipitating nickel hydroxide and heating the hydroxide in air at 300°C. The resulting nickel oxide films behave as an electrochemical capacitor with a specific capacitance of 59 F/g electrode material. These nickel oxide films maintain high utilization at high rates of discharge (i.e., high power density) and have excellent cycle life. Porous cobalt oxide films were also synthesized. Although the specific capacitances of these films are approximately one-fifth that of the nickel oxide films, the results demonstrate the versatility of fabricating a wide range of porous metal oxide films using …


Molecular-Level Modeling Of The Viscoelasticity Of Crosslinked Polymers: Effect Of Time And Temperature, Philip P. Simon, Harry J. Ploehn Jan 1997

Molecular-Level Modeling Of The Viscoelasticity Of Crosslinked Polymers: Effect Of Time And Temperature, Philip P. Simon, Harry J. Ploehn

Faculty Publications

We present a new molecular-level picture of chain dynamics for describing the viscoelasticity of crosslinked polymers. The associated mathematical model consists of a time-dependent momentum balance on a representative polymer segment in the crosslinked network, plus phenomenological expressions for forces acting on the segments. These include a cohesive force that accounts for intermolecular attraction, an entropic force describing the thermodynamics governing chain conformations, and a frictional force that captures the temperature dependence of relative chain motion. We treat the case of oscillatory uniaxial deformation. Solution of the model equations in the frequency domain yields the dynamic moduli as functions of …


Assessment Methods For Virtual Laboratories In Civil Engineering Technology, Carol L. Considine, Vernon W. Lewis Jr. Jan 1997

Assessment Methods For Virtual Laboratories In Civil Engineering Technology, Carol L. Considine, Vernon W. Lewis Jr.

Engineering Technology Faculty Publications

Old Dominion University has developed an extensive distance learning system that includes 40 remote sites. A majority of the sites are located at community colleges. There are 30 sites in Virginia, three sites in North Carolina, one site in Washington State and one site in Arizona. In addition, there are four sites at Higher Education Centers in Virginia and one site at a local industrial facility. The Civil Engineering Technology curriculum requires three laboratory courses, which are a challenge in the distance learning environment because of the lack of laboratory equipment and computers at the broadcast sites. The three courses …


Practice And Fit In The Allocation Of The Resource Of Faculty Time: A Study Of Current And Preferred Scholarly Practice Of The Faculties Of Ten Theological Schools Affiliated With The Presbyterian Church (Usa), Roger Allen Nicholson Jan 1997

Practice And Fit In The Allocation Of The Resource Of Faculty Time: A Study Of Current And Preferred Scholarly Practice Of The Faculties Of Ten Theological Schools Affiliated With The Presbyterian Church (Usa), Roger Allen Nicholson

Theses and Dissertations

Faculties, deans, and trustees of theological schools affiliated with the Presbyterian Church (USA) were surveyed to determine current faculty practice; the practice preferred by faculty, deans. and trustees; the fit between current and preferred practice; and faculty practice and faculty preference difference according to categorical variables such as gender, race, and rank.

Seven variables defined faculty practice: workweek in hours, instruction, scholarship, service, advising, governance, and other. Scholarship was subdivided into three categories adapting Ernest Boyer’s multi-dimensional definition of scholarship: orginitive, applied, and teaching. Fit was defined in two ways: statistical fit and practical fit.

The reported workweek was comparable …


A Monte Carlo Model Of Uncertainty In A Deterministic Hazardous Waste Transportation Risk Assessment, Michael A. Cowen Jan 1997

A Monte Carlo Model Of Uncertainty In A Deterministic Hazardous Waste Transportation Risk Assessment, Michael A. Cowen

Masters Theses

This thesis is aimed at developing and applying advanced modeling tools in the prediction of risk to the general public from transportation of chemical waste on public highways. The modeling tools developed can then be used to compare alternative waste management scenarios. The application considered is related to the transport of hazardous waste generated by the United States Department of Energy (DOE) to current treatment, storage, and disposal facilities. DOE is currently considering four different scenarios.

The application considered can be more specifically defined as an analysis of the risk to the general public from transporting the 63 shipments of …


Mechanical And Tribological Properties Of Composites Of Recycled High Density Polyethylene And Recycled Rubber, Jason G. Boulanger Jan 1997

Mechanical And Tribological Properties Of Composites Of Recycled High Density Polyethylene And Recycled Rubber, Jason G. Boulanger

Masters Theses

This thesis presents a study on the mechanical and tribological properties of composite materials of recycled high density polyethylene (HDPE) and recycled rubber tire particles. The materials were compounded by extrusion and formed into test specimens by injection molding.

The first experiment studied the effect of recycled rubber percentage on mechanical properties of composites of recycled HDPE and recycled rubber. The mechanical properties included tensile strength, percent elongation, hardness, and impact resistance. Recycled rubber concentrations of 0, 5, 10, 15, 20, 25, and 30 percent were tested. The second experiment investigated the tribological properties of recycled HDPE and recycled rubber …


A Self-Consistent Power Relation For An Inverse Compton Scattering Theory, Robert A. Schill Jr. Jan 1997

A Self-Consistent Power Relation For An Inverse Compton Scattering Theory, Robert A. Schill Jr.

Electrical & Computer Engineering Faculty Research

In a self-consistent manner, the total power for linear inverse Compton scattering between a Gaussian electron beam colliding head on with a Gaussian laser beam is obtained. The theory is shown to agree with well-known limiting cases. Coupling among harmonic modes is explicitly shown in the resultant power relation. Even so, for the parameters of interest, harmonic modes are negligible compared to the fundamental mode. Total power calculations are of importance in detector calibration. The theory is applied using practical linear accelerator and laser parameters.


Damage Detection Of Bridge-Like Structures Using State Space Models, Javier Valentin Sivico Jan 1997

Damage Detection Of Bridge-Like Structures Using State Space Models, Javier Valentin Sivico

Masters Theses

"A global damage detection algorithm for bridge-like structures is proposed. This method provides the capability of determining the reduction in both stiffness and damping parameters of the structural elements. It is assumed the mass of the structural elements is not affected by the damages, which is a reasonable assumption for bridge-like structures. The proposed method uses the state space representation of the structural dynamics to make the diagnosis of the structural integrity. Given that the state space representation of any system is not unique, the damage detection procedure is developed for the physical coordinates of the state space representation. A …


Urban Infrastructure: Transportation, Public Utilities, Waste Management And Pollution Control, A. Bruce Bishop Jan 1997

Urban Infrastructure: Transportation, Public Utilities, Waste Management And Pollution Control, A. Bruce Bishop

Civil and Environmental Engineering Faculty Publications

Paris, tube under the channel -- London, satellite spinning above cables on the ocean floor -- New York, concrete ribbons across undulating land -- San Francisco, silver wings soaring across the Pacific -- Tokyo and Seoul. Etched against the sky are the graceful towers of mighty bridges, the broad glass and steel fronts to massive buildings, the tall slender stacks of industries exhaling; and traced on the surface are the intricate patterns of people and their machines; and buried below are the tubes and tunnels, water pipes and power conduits and communication networks along with concrete caissons and piles that …


Introduction To Simulation/Optimization Modeling For Groundwater Containment Remediation And (B) Ramifications Of Applying S/O Modeling To Groundwater Containment Remediation, With Case Study Examples, Richard C. Peralta Jan 1997

Introduction To Simulation/Optimization Modeling For Groundwater Containment Remediation And (B) Ramifications Of Applying S/O Modeling To Groundwater Containment Remediation, With Case Study Examples, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Normal use of a simulation model to develop a groundwater extraction/injection strategy employs the following process: (1) specify management goals, (2) assume a pumping strategy, (3) simulate system response to the pumping strategy, (4) evaluate acceptability of the system responses, (5) repeat steps (2-4) as required. This is a trial and error approach that is unlikely to actually yield the best pumping strategy for complicated problems


Optimal System Design Of In-Situ Bioremediation Using Parallel Recombinative Simulated Annealing, Horng-Jer Shieh, Richard C. Peralta Jan 1997

Optimal System Design Of In-Situ Bioremediation Using Parallel Recombinative Simulated Annealing, Horng-Jer Shieh, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

We present a simulation/optimization model combining optimization with BIOPLUME II simulation for optimizing in-situ bioremediation system design. In-situ bioremediation of contaminated groundwater has become widely accepted because of its cost-effective ability to achieve satisfactory cleanup. We use parallel recombinative simulated annealing to search for an optimal design and apply the BIOPLUME II model to simulate aquifer hydraulics and bioremediation. Parallel recombinative simulated annealing is a general-purpose optimization approach that has the good convergence of simulated annealing and the efficient parallelization of a genetic algorithm. This is the first time that parallel recombinative simulated annealing has been applied to groundwater management. …


Optimal In-Situ Bioremediation System Design Using Parallel Recombinative Simulated Annealing, Horng-Jer Shieh, Richard C. Peralta Jan 1997

Optimal In-Situ Bioremediation System Design Using Parallel Recombinative Simulated Annealing, Horng-Jer Shieh, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Presented is a simulation/optimization (S/0) model combining optimization with BIOPLUME II simulation for optimizing in-situ bioremediation system design. The (S/0) model uses parallel recombinative simulated annealing to search for an optimal design and applies the BIOPLUME II model to simulate aquifer hydraulics and bioremediation. Parallel recombinative simulated annealing is a general-purpose optimization approach that has the good convergence of simulated annealing and the efficient parallelization of a genetic algorithm. We propose a two-stage management approach. The first stage design goal is to minimize total system cost (pumping/treatment, well installation and facility capital costs). The second stage design goal is to …