Engineering Commons^™

Nebraska Summary: S155 John Deere 6200, 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: S154 John Deere 6200, 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: S156 John Deere 6300, 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 …

Structural Properties Of Mixtures Of Highly Asymmetrical Electrolytes And Uncharged Particles Using The Hypernetted Chain Approximation, Daniel Forciniti, Carol K. Hall

Chemical and Biochemical Engineering Faculty Research & Creative Works

We have solved the Ornstein-Zernike equation in the hypernetted chain (HNC) approximation for several mixtures of electrolytes and uncharged hard spheres. The mixtures that we studied range from a simple restricted primitive model plus hard spheres of the same size to highly asymmetric electrolytes plus hard spheres of different sizes. We monitored the radial distribution function and thermodynamic properties. We find that the presence of neutral particles changes the nature of the interaction between the charged particles. We also find a strong correlation between nonelectrostatic and electrostatic contributions to the free energy of the mixtures. Potential applications of this approach …

Dominance Of The Thomas Mechanism For Electron Capture From Orientated Rydberg Atoms, Jee-Ching Wang, Ronald E. Olson

Chemical and Biochemical Engineering Faculty Research & Creative Works

We investigate electron capture from initially oriented circular Rydberg atoms by proton impact at collision speeds comparable to the electron orbital speed. The Thomas double scattering mechanism is observed even at these low relative speeds. Furthermore, we find evidence for the dominance of a quasi Thomas capture mechanism in the form of not a single peak, but a double-peaked structure in the differential cross section when the plane of the circular orbit is nearly perpendicular to the incident direction of the projectile. © 1994 The American Physical Society.

Multiphase Equilibrium Behavior Of The Mixture Carbon Dioxide + Ethane + Methanol, Seung Pyo Hong, Christi L. Patton (Luks), Kraemer D. Luke

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Three-Phase Liquid-Liquid-Vapor (Llg) Phase Equilibrium Behavior of the Mixture Carbon Dioxide + Ethane + Methanol Was Experimentally Studied. the Boundaries of the Three-Phase Llg Region in Pressure-Temperature Space Are Delineated. Compositions and Molar Volumes of the Two Liquid Phases and the Vapor Phase Along the 288.15 and 298.15 K Isotherms Are Reported. © 1994, American Chemical Society. All Rights Reserved.

A Study Of Similarity And Analogical Decision-Making In Collaborative Design, Christopher Edward Weeks

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this study is to investigate the role of similarity and analogy in design communication and propose a descriptive representation of the analogical decision-making process in the context of engineering design. It is proposed that social, cultural, and contextual knowledge are brought to bear on statements of need in the form of analogy as a means to elicit and evince potential design solutions. A goal of this study is to identify communicative behaviors, representing process variables of analogical decision-making, that can be used to describe how design information is represented, manipulated, and conveyed in a collaborative design effort. …

Materials Recovery Facilities In The United States Virgin Islands: A Regional Facilities Location Model Study, Lloyd O. Prince Jr.

Engineering Management & Systems Engineering Theses & Dissertations

Continental municipalities have derived many benefits from the economies of scale associated with a regional approach to facilities location and management planning. Centralized solid waste processing facilities is an example. Island communities, however, surrounded by miles of ocean, are constrained to a fragmented approach to the facilities location solution. This research was conducted to determine if the regional paradigm suggested in the literature is applicable to a set of island communities connected by an ocean transportation infrastructure. A linear programming (LP) model, constraints and data requirements were developed and applied to a network of islands. A series of hypothetical material …

Teamwork In The Workplace: A Discovery Of The Work Processes One Team Used To Meet Its Goals, Thomas Andrew Hassler

Engineering Management & Systems Engineering Theses & Dissertations

A century-old disagreement in academia surrounds the question of whether individuals acting alone accomplish all work or whether workers can truly act in concert to meet management's production requirements. Total Quality Management (TQM) is a powerful force today in the industrial world, and the formation of teams to solve short-term problems is one of its fundamental techniques. This dissertation focuses on a particular TQM team with the purpose of understanding the processes it used to meet its goals. This ten-member team functioned for about one year and was assigned goals leading to improved accelerator reliability. The investigator was a member …

Buckling Of A Coating Bonded To A Round Bar Subjected To Axial Extension. Mech. Mater. 15 (1993) 131-138, C. W. Bert, Victor Birman

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

On The Propagation Of A Shear Band In A Steel Tube, R. C. Batra, Xiangtong Zhang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Marchand and Duffy tested thin-walled steel tubes in a split Hopkinson torsion bar at a nominal strain-rate of approximately 1600/s and could not determine conclusively whether a shear band initiating at a point in the tube propagated around the circumference in one direction or in both directions. They estimated the speed of propagation to be 520 m/s in the former case and 260 m/s in the latter. Here we simulate their test numerically and find that the shear band propagates in both directions around the circumference of the tube. When the tube is twisted at a nominal strain-rate of 5000/s, …

Numerical Simulation Of The Nonlinear Response Of Composite Plates Under Combined Thermal And Acoustic Loading, Jayashree Moorthy

Mechanical & Aerospace Engineering Theses & Dissertations

A time-domain study of the random response of a laminated plate subjected to combined acoustic and thermal loads is carried out. The features of this problem also include given uniform static inplane forces. The formulation takes into consideration a possible initial imperfection in the flatness of the plate. High decibel sound pressure levels along with high thermal gradients across thickness drive the plate response into nonlinear regimes. This calls for the analysis to use von Karman large deflection strain-displacement relationships. A finite element model that combines the von Karman strains with the first-order shear deformation plate theory is developed. The …

Finite Element Analysis For Nonlinear Flutter Suppression Of Composite Panels At Elevated Temperatures Using Piezoelectric Materials, Run Chen Zhou

Mechanical & Aerospace Engineering Theses & Dissertations

Nonlinear coupled finite element equations of motion are derived for composite panels with embedded piezoelectric layers subjected to aerodynamic, thermal loads and applied electric fields. The nonlinear equations of motion describe the coupling between a structure and an electrical network through the piezoelectric effect. The von Karman large-deflection strain-displacement relations, quasi-steady first-order piston theory aerodynamics, quasi-steady thermal stress theory and linear piezoelectricity theory are used to formulate the nonlinear coupled panel flutter finite element equations of motion in nodal displacements. The governing equations, which are referred to actuator and sensor equations, form a basis for piezoelectric actuation and sensing. Following …

Field Tests Of The Dolphin--A Remotely Operated Survey Vehicle, M T. Kalcic, Edit J. Kaminsky

Electrical Engineering Faculty Publications

No abstract provided.

Measurement Of Acoustic Impedance And Reflectance In The Human Ear Canal, Susan E. Voss, Jont B. Allen

Engineering: Faculty Publications

The pressure reflectance R(ω) is the transfer function which may be defined for a linear one‐port network by the ratio of the reflected complex pressure divided by the incident complex pressure. The reflectance is a function that is closely related to the impedance of the 1‐port. The energy reflectance ℛ(ω) is defined as ‖R‖². It represents the ratio of reflected to incident energy. In the human ear canal the energy reflectance is important because it is a measure of the inefficiency of the middle ear and cochlea, and because of the insight provided by its …

Extending Simulation’S Advantages To Novice Model Builders: Intellisim Tutorial, Paul Savory, Gerald Mackulak, Jeff Cochran

Department of Industrial and Management Systems Engineering: Faculty Publications

The potential benefits that discrete-event simulation offers are impeded by the high level of expertise necessary to successfully conduct a sound simulation study. As a solution, this paper introduces IntelliSIM, an intelligent simulation environment. Using this environment makes simulation more accessible to users by reducing the need for extensive experience or training. One of IntelliSIM’s key features for accomplishing this is a tutorial and training module that quickly acquaints a novice simulation user with IntelliSIM’s features and the process of performing a simulation study. This paper discusses this tutorial by explaining how IntelliSIM develops a simulation model, thus illustrating how …

Ascertaining Important Features For Industrial Simulation Environments, Gerald Mackulak, Jeffery Cichran, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

Recent years have witnessed the development and commercial release of multiple simulation tools, environments, and intelligent simulators. Each release seems to contain additional advanced features designed to simplify simulation use and increase the productivity of model builders. But to date, no one has addressed feature definition from the viewpoint of a simulation practitioner. This paper discusses our efforts to identify and prioritize simulation features deemed most desirable from the practitioner viewpoint. A series of three questionnaires were developed and administered to a group of qualified simulation practitioners. With results that are of interest to simulation users, researchers, and simulation software …

Darcy-Weisbach Roughness Coefficients For Selected Crops, John E. Gilley, E. R. Kottwitz

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Total hydraulic resistance on an upland agricultural site may be influenced by several factors including standing vegetation. In this laboratory study, Darcy-Weisbach roughness coefficients were measured for corn, cotton, sorghum, soybeans, sunflower, and wheat vegetation. Experimental variables used in this investigation in addition to crop type included plant population, row spacing, row orientation, and flow rate. For some of the experimental tests, a single row of vegetation was oriented within a flume parallel to the principal flow direction. For the remainder of the tests, rows of vegetation were placed perpendicular to the flow using row spacings and plant populations recommended …

Tillage And Planting System, Stalk Chopper, And Knife Applicator Influences On Corn Residue Cover, David P. Shelton, Stephen D. Kachman, Elbert C. Dickey, K.T. Fairbanks, Paul J. Jasa

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Percent corn (Zea mays L.) residue cover remaining on the soil surface after planting was measured for 11 tillage and planting systems that included combinations of the use, and timing, of a stalk chopper and/or a knife-type fertilizer applicator. Tillage, as well as use of a stalk chopper or knife applicator, significantly reduced residue cover. Only 27 of the 69 stalk chopper/knife applicator/tillage and planting system treatment combinations that were evaluated could be classified as conservation tillage by having at least 30% residue cover remaining after planting.

Effect Of Proton Diffusion, Electron Conductivity, And Charge-Transfer Resistance On Nickel Hydroxide Discharge Curves, John W. Weidner, Paul Timmerman

Faculty Publications

Constant-current discharge curves for the nickel hydroxide electrode are simulated assuming resistances due to diffusion of protons and conduction of electrons through the nickel hydroxide film, and charge-transfer resistance at the film/electrolyte interface contribute to the polarization losses of the electrode. Good qualitative agreement is observed between the model predictions and experimental discharge curves. The results suggest that polarization losses due to diffusional limitations of protons is a critical factor in determining the characteristics of the discharge curve. Ohmic resistance has a significant effect on the discharge curves at the end of discharge, and charge-transfer resistance is a minor contributor …

Theoretical Analysis Of The Discharge Performance Of A Niooh/H2 Cell, Z. Mao, P. De Vidts, Ralph E. White, John Newman

Faculty Publications

A mathematical model is presented for the discharge of a NiOOH/H₂ cell. This model includes diffusion and migration in the electrolyte phase as well as proton diffusion and ohmic drop across the solid active material in the porous nickelelectrode. A theoretical analysis of the cell performance is presented for different design parameters using this model. It is predicted that proton diffusion in the solid active material is the main factor in limiting the cell voltage and the utilizationof the active material. It is also predicted that use of a thick nickel electrode is an effective method for increasing electrode …

Thermal Characteristics Of A Nickel-Hydrogen Battery, Junbom Kim, T. V. Nguyen, Ralph E. White

Faculty Publications

The maximum allowable temperature difference inside a nickel-hydrogen battery to avoid water relocation was calculated by using a graphical method together with a vapor pressure vs. temperature correlation equation for water vapor over potassium hydroxide solution. An equation was developed for this maximum allowable temperature difference for vessel-wall temperatures from 0 to 30°C and potassium hydroxide concentrations from 20 to 32%. A heat-generation equation for the nickel-hydrogen battery was used to investigate the effect of the location of heat generation on the maximum temperature in the cell and the temperature distribution in the cell.

Neutron-Scattering Study Of Librations And Intramolecular Phonons In Rb_{2.6}K_{0.4}C_{60}, D. Reznik, W. A. Kamitakahara, D. A. Neumann, J. R. D. Copley, J. E. Fischer, Robert M. Strongin, M. A. Cichy, Amos B. Smith Iii

Chemistry Faculty Publications and Presentations

We report the results of inelastic neutron-scattering measurements on Rb_2.6K_0.4C₆₀. Librational modes were observed as broad peaks with maxima between 4.1 and 4.7 meV, as the temperature is lowered from 300 to 12 K. As in K₃C₆₀, no change in the width or position of the librational peak was observed when the sample was cooled through the superconducting transition. Thus any coupling of the librations to electronic states is small. The magnitude of the orientational potential barrier was estimated from the librational peak frequency. A flat background observed in the …

An Analysis Of The Payback Potential Of New Lighting Technology, James L. Cox

Masters Theses

Recent, energy saving improvements in lighting technology have been made involving the use of more efficient lamps, silver coated light reflectors, and electronic light ballasts. Research indicates that it is economically feasible to retrofit existing light fixtures to utilize the advantages of these developments. This process consists of the removal of all standard lamps and ballasts in each light fixture, the installation of a highly refined light reflector and the replacement of the existing lamps with brighter, more efficient ones. Standard magnetic ballasts are exchanged for more efficient electronic ballasts. Resulting is a light fixture that produces a comparable amount …

An Investigation Of Recycled High Density Polyethylene Reinforced By Short Glass Fibers, Tony Lynn Alwardt

Masters Theses

The mechanical properties of recycled high density polyethylene (HDPE) reinforced by short glass fibers were investigated. The composites formed by an injection molding process were examined in terms of tensile strength, percent elongation, and hardness. Recycled HDPE was compared to virgin HDPE regarding the effects of fiber concentrations, types, sizes, and treatments. The addition of three coupling agents at different concentrations was investigated.

The virgin HDPE composites slightly outperformed their recycled HDPE counterparts; having higher tensile strength and hardness, but were less ductile. Increase in fiber concentration generally increased the tensile strength and hardness, but the concentration of fibers was …

Hycrest Crested Wheatgrass Accelerates The Degradation Of Pentachlorophenol In Soil, A. Ferro, Ronald C. Sims, B. Bugbee

Biological Engineering Faculty Publications

We investigated the effects of vegetation on the fate of pentachlorophenol (PCP) in soil using a novel high-flow sealed test system. Pentachlorophenol has been widely used as a wood preservative, and this highly toxic biocide contaminates soil and ground water at many sites. Although plants are known to accelerate the rates of degradation of certain soil contaminants, this approach has not been thoroughly investigated for PCP. The fate of [14C]PCP, added to soil at a concentration of 100 mg/kg, was compared in three unplanted and three planted systems. The plant used was Hycrest, a perennial, drought-tolerant cultivar of crested wheatgrass …

Information Processing Using Laser Speckle, Rathnakar Gopisetty

Masters Theses

"The random speckle intensity pattern, which is produced by the scattered optical field from a rough surface when illuminated, can be used as a carrier of information. A theoretical study is performed to use the speckle patterns for retrieving the information of various kinds of object motions. A mathematical model of speckle is developed and used to relate different speckle patterns at various intervals as the object is experiencing motion. Four different object motions, i.e., one dimensional perpendicular motion, axial motion, three-dimensional motion, and rotational motion of an object are analyzed. In each case an interference pattern is produced which …

Antecedent Moisture Conditions For Utah Local Storm Probable Maximum Floods, Travis S. Taylor, David S. Bowles

Reports

Introduction: The critical inflow design flood for most dams in Utah is the probable maximum flood (PMF) resulting from the local storm probable maximum precipitation (PMP) event. Commonly, the Soil Conservation Service (SCS) curve number method is used to determine the PMF from the local storm PMP. An important factor in this determination is the assumption of antecedent moisture conditions (AMC) existing immediately prior to the onset of the PMP event. At one northern Utah dam site the use of AMC III increased the PMF peak flowrate by 50 percent over the peak obtained when AMC II was used (Win …

Low Frequency Climate Variability: Understanding The Rise And Fall Of The Great Salt Lake, Michael E. Mann, Upmanu Lall, Barry Saltzman

Reports

Connections between the Great Salt Lake (GSL) volume (V) and large-scale climate variations are developed through an analysis of the time series of the month-to-month differences in V (change in V), local precipitation and streamflow, and gridded U.S. sea level pressure and global temperature data. We isolate decadal and secular mdoes of cliamte variability that are coherent with change in V variations. The decadal variations results from a low-frequency north-south shifting of storm tracks which influence winter precipitation. These variations describe nearly 18% of the interannual variance in change in V, while the secular trend accounts for only ~1.5%. The …

Introducing Uncertainty Of Aquifer Parameters Into An Optimization Model, Robert L. Ward, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

A stochastic analysis is made for a previously described groundwater contaminant management model {Peralta and Ward, 1988). The stochastic model is based on incorporating uncertainty of the aquifer parameters transmissivity and effective porosity into the model. This is accomplished by finding the partial derivative of drawdown with respect to each of these parameters using a Taylor series expansion approximation of the Theis equation. Input that is required for the stochastic version is the mean of the transmissivity and effective porosity, the coefficient of variation of the transmissivity and effective porosity, and a reliability level (0%-100%) . The reliability is a …