Engineering Commons^™

Effect Of Screw Configuration And Speed On Rtd And Expansion Of Rice Extrudate, Siew-Yoong Lee, Kathryn L. Mccarthy

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The influence of screw configuration and screw speed on the residence time distribution and product expansion was determined for rice meal processed in a corotating twin screw extruder. Screw speed had strong effect on the E(t)- and F(t)-diagrams, with the mean residence time varying inversely with screw speed from 206 s to 256 s. the F-diagram was modeled by the combination of perfect mixing and plug flow. the P estimates, which express the fraction of material in plug flow, varied inversely with screw speed from 0.41 to 0.55 for the operating conditions in this study. Both screw configuration and screw …

Development And Operation Of Buried Channel Charge Coupled Devices In 6h Silicon Carbide, Scott T. Sheppard, Michael R. Melloch, James A. Cooper Jr.

Department of Electrical and Computer Engineering Technical Reports

Silicon carbide is a wide bandgap semiconductor that is well suited for high power, high temperature electronic devices due to its remarkable electronic and thermal properties. Photosensitive devices in the 6H polytype of Sic have also been demonstrated, showing high sensitivity in ultraviolet wavelengths near 270 nm. Furthermore, the native oxide on Sic is silicon dioxide, meaning that SIC can be thermally oxidized to form a high quality gate dielectric, making metal-oxide-semiconductor (MOS) devices possible. These qualities make silicon carbide ideal for constructing UV sensitive CCD imagers. 'This work investigates the feasibility for developing imagers in Sic through the fabrication …

Applications Of The Normal-Incidence Rotating-Sample Ellipsometer To High- And Low-Spatial-Frequency Gratings, Y. Cui, R. M.A. Azzam

Electrical Engineering Faculty Publications

The normal-incidence rotating-sample ellipsometer is an instrument that can be used to characterize grating surfaces from the measured ratio ρof complex reflection coefficients r_y/r_x of light polarized perpendicular and parallel to the grating groove direction. Experimental results at different wavelengths for different gratings with spatial frequencies from 150 to 5880 grooves/mm are presented. The groove depth of the 5880-grooves/mm gold-coated grating can be estimated from the measured ρ and rigorous grating theory.

Storage And Delivery Constrained Unit Commitment, Y. Al-Kalaani, F. Eugenio Villaseca, F Renovich Jr

Electrical and Computer Engineering Faculty Publications

A general formulation and the development of a dynamic programming algorithm to solve a fuel-constrained unit commitment problem is presented. The system under consideration has oil units with storage constraints, gas units with delivery constraints, and unconstrained coal units. An optimal approach to transfer the fuel delivery constraints into unit capacity limits using a closed-form dual dispatch is introduced. As a result, the gas units can be viewed as fuel-unconstrained, thus greatly reducing complexity. It is shown that the optimization problem, which requires that storage levels be parameterized, leads to two different dispatch rules. The oil units are dispatched to …

A Spatially-Distributed Hydrologic Model For A Small Arid Mountain Watershed, Thomas H. Jackson, David G. Tarboton, Keith R. Cooley

Civil and Environmental Engineering Faculty Publications

A distributed water balance model was developed as a part of an intensive-field study to simulate the snowmelt-driven hydrologic response of a small mountain watershed using measured values of solar radiation, wind speed, air temperature, relative humidity and precipitation as input.

Snowmelt and evapotranspiration were modeled with point energy balances, written in terms of the snow surface and soil surface temperatures, respectively, corrected for local topographic characteristics and snow drifting. Meltwater was routed to the basin outlet as topography-driven, saturated subsurface flow, with all flow in excess of local transmissivity taken as surface runoff.

The model was calibrated with 1985-6 …

Toward A Balanced Strategy To Address Contaminated Groundwater Plumes At The Massachusetts Military Reservation, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

This document contains the findings and recommendations of the Technical Review and Evaluation Team (TRET) for the plume containment project at the Massachusetts Military Reservation (MMR). The findings and recommendations are in response to the 60 Percent Plume Containment Design, submitted by Operational Technologies (OpTech) in January 1996. In short, the TRET recommends the MMR depart substantially from the strategy of simultaneous, 100 percent containment and treatment that was assigned to OpTech for design in accordance with the Record of Decision (ROD) for Interim Action. This strategy guided the course of the plume containment project over the past two years

Extensive Study Of The Pvc Industry: Relation Of The Processing Time And Processing Temperature To The Degree Of Fusion, As Well As A Strategic Plan For Increasing Consumer Demand, Erick Jason Comeaux

Honors Capstones

No abstract provided.

Cost Competitiveness Of Airlines: An International Comparison, Tae Oum, Chunyan Yu

Publications

Significant structural, institutional and regulatory changes have occurred in the airline industry since the mid-1980s. These changes have intensified competition in both domestic and international air transport market. As the market becomes more competitive, the ultimate ability of a carrier to survive and prosper depends greatly on its cost competitiveness. This paper measures and compares the unit cost competitiveness of the world's major airlines, using the yearly panel data of 23 major airlines over the 1986-93 period. We focus our analysis on identifying the potential factors which influence the observed unit cost differentials among airlines, including input prices, productivity, network …

Dependence Of The Normalized Radar Cross Section Of Water Waves On Bragg Wavelength-Wind Speed Sensitivity, David G. Long, R. Scott Collyer, David V. Arnold

Faculty Publications

Measurements of the normalized radar cross section (O) made by the YSCAT ultrawideband scatterometer during an extended deployment on the Canada Centre for Inland Waters (CCIW) Research Tower located at Lake Ontario are analyzed and compared with anemometer wind measurements to study the sensitivity of O to the wind speed as a function of the Bragg wavelength. This paper concentrates on upwind and downwind azimuth angles in the wind speed range of 4.5-12 m/s. While YSCAT collected measurements of O at a variety of frequencies and incidence angles, this paper focuses on frequencies of 2.0, 3.05, 5.30, 10.02, and 14.0 …

Evaluation Of Superior Performing Portland Cement Concrete Pavements In Kentucky, Jerry G. Rose, Bobby W. Meade, David Q. Hunsucker

Kentucky Transportation Center Research Report

This research report describes a program of study directed at determining common factors which have contributed to the superior performances of selected sections of Portland cement concrete (PCC) pavements in Kentucky. The program involved an extensive survey of Kentucky's interstate, partway and other primary routes to determine locations of PCC pavement sections greater than 15 years old that had performed satisfactorily with minimal maintenance. Twelve of the best performing PCC pavements with long service life and heavy traffic were selected for detailed evaluations. Initial designs were documented and a series of in-situ pavement tests were conducted including core dnlling and …

Discharge Coefficient Scale Effects Analysis For Weirs, Michael Clyde Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Much work has been published regarding discharge coefficients for various weir structures. What has not been published to the same extent are the effects of model scale associated with the weirs being studied. If laboratory weirs are too small, scale effects can affect the magnitude of the discharge coefficient. These errors may be significant if the weir serves as a control structure for an emergency spillway. It is imperative that discharge be accurately predicted to enable safe design and operation.

Numerical and physical means were employed to analyze the effects of scale associated with Froude Modeling of weirs with sharp …

Experimental And Theoretical Study Of Vibrations Of A Cantilevered Beam Using A Zno Piezoelectric Sensor, B. R. Jooste, Hendrik J. Viljoen, S. L. Rohde, N. F. J. Van Rensburg

Hendrik J. Viljoen Publications

Piezoelectric sensors can measure vibrations of solid structures very accurately. A model of a cantilevered beam, with a ZnO film on one side is presented. Both viscous and internal damping are considered. The output of the sensor is modeled and matched with experimental results by adjusting the damping parameters. A theoretical formulation for damage is introduced. Experimental results for a damaged beam confirm the shift in frequencies to lower values. The model is used to identify the extent of the damage.

A Fuzzy Logic Based Approach To Direct Load Control, K. Bhattacharyya, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Demand side management programs are strategies designed to alter the shape of the load curve. In order to successfully implement such a strategy, customer acceptance of the program is vital. It is thus desirable to design a model for direct load control which may accommodate customer preferences. This paper presents a methodology for optimizing both customer satisfaction and utility unit commitment savings, based on a fuzzy load model for the direct load control of appliances

Evaluation Of Edge Drains On Pennyrile Parkway Webster County, L. John Fleckenstein, David L. Allen

Kentucky Transportation Center Research Report

This report documents findings of the investigation of pipe edge drains and outlets on the Pennyrile Parkway from Milepost 60.476 to Milepost 65.305 in Webster County. The study was initiated due to concerns from District 2 personnel that possible failures in the edge drains were causing pavement distress along the right wheel path. Findings from this study indicated that approximately 40 percent of the 123 edge drain outlets were less than 50 to 60 percent open. The round perforated pipe edge drain appeared to be in excellent condition, including the integrity of the pipe and the filter material. The sand …

Organic Matter Characterization Of Virginia Rivers And Reservoirs, Susanne Margaret Lockhart

Civil & Environmental Engineering Theses & Dissertations

Research was conducted on characterizing the DOC characteristics and to discern whether spatial and temporal variations exist in these characteristics as impacted by seasonal, hydrologic or other factors. Data was cumulative of two studies: the State-Wide Survey in which water samples were taken in March and July 1995 from surface waters in four physiographic regions of Virginia and the James River Peninsula Survey concentrating on reservoirs and rivers on the James River Peninsula.

Results illustrate that the two largest fractions of DOC were the hydrophilic and hydrophobic acid fractions. An increase in DOC was observed between the mountains and the …

Bs News

Building Services Engineering

No abstract provided.

Dispersion Comparison For Dsi- And Tensor-Based Nonorthogonal Fdtd, Hao Shi, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

An explicit formulation of the finite-difference time-domain-discrete surface integral (FDTD-DSI) technique has allowed a rigorous study of numerical dispersion for the method. The study shows that the DSI- and tensor-based FDTD methods do not have the same numerical dispersion relation. It also clarifies the recently reported discrepancies in the dispersion relation between the two approaches. This study also shows that the tensor-based FDTD algorithm exhibits better dispersion properties for a two-dimensional uniformly skewed mesh.

Implementation Of An Integrated Cost And Schedule Control System In The Egyptian Construction Industry, Nahla Mofid El-Ebiary

Archived Theses and Dissertations

No abstract provided.

Effect Of River Impoundment On Its Water Salinity And Associated Environmental Impacts, Ayat Ahmed Soliman

Archived Theses and Dissertations

No abstract provided.

Developing An Expert System For Processing Planning, Mahmoud M Abdel Wahab

Archived Theses and Dissertations

No abstract provided.

Waste Steel Chips From Workshops As A Substitute For Fiber Reinforcement In Concrete, Alaa Abdultawab Abulella

Archived Theses and Dissertations

No abstract provided.

Layout Synthesis For Datapath Designs, Naveen Buddi

Dissertations and Theses

As datapath chips such as microprocessors and digital signal processors become more complex, efficient CAD tools that preserve the regularity of datapath designs and result in small layout area are required. The standard-cell placement techniques ignore the regularity of datapath designs and hence give inefficient layouts. This has necessitated the development of new techniques for datapath module placement.

We developed a layout synthesis tool DataPathLAYOUT, for the bit-slice datapath logic designed using standard-cell libraries. We developed fast and area efficient heuristics for placing the cells in a bit-slice such that the regularity of datapath circuits is preserved and the number …

Software Design Control Of An Autonomous Vehicle, Monish Sharma

Honors Capstone Projects and Theses

No abstract provided.

Space Trajectory Simulation For The Internet, Michael Selby, Patrick Newton

Honors Capstone Projects and Theses

No abstract provided.

Daylighting Dimming And Energy Savings: The Effects Of Window Orientation And Blinds, Florida Solar Energy Center, Lynn Schrum

FSEC Energy Research Center®

The Daylighting Test Facility (DTF) located at Florida Solar Energy Center, was used to study daylight dimming systems and how orientation and blinds effect energy savings. To evaluate the impact of blinds on dimming savings, the energy consumption was compared in two pairs of offices for all four window orientations: north, south, east and west. One office in each pair had blinds in a fixed position (down and open) and the other office had no blinds. From September through December of 1994, data were collected on the north- and south-facing offices. The DTF was rotated 90 degrees and data were …

Explosive Compaction Of Magnequench Nd–Fe–B Magnetic Powders, S. Guruswamy, M.K. Mccarter, Jeffrey E. Shield, V. Panthanachan

Nebraska Center for Materials and Nanoscience: Faculty Publications

Magnequench NdFeB powders having high and low rare earth contents were explosively compacted to obtain cylindrical magnets. The magnetic properties were found to be isotropic and were superior to conventionally consolidated isotropic magnets. The (BH) _max was 14.7 MGOe and the remanence was 8.7 kG for the explosively compacted magnet with lower rare earth content. X-ray diffraction patterns confirm the explosively compacted magnet to be crystalline and the predominant phase to be the 2-14-1 phase. Transmission electron microscopy examination showed a microstructure to consist of 20–25 nm size equiaxed grains consistent with the magnetic measurements.

In Situ And Ex Situ Optical Characterization Of Electro Deposited Magneto-Optic Materials, James N. Hilfiker, Darin W. Glenn, Scott W. Heckens, John A. Woollam, Kurt W. Weirman

Department of Electrical and Computer Engineering: Faculty Publications

Electrodeposition is being investigated as a novel and low-cost method to prepare magneto-optic thin film and nanostructured materials. This deposition method allows precise control over thin-film properties and permits deposition of novel magnetic geometries. Multilayers and alloys can be deposited and controlled by adjusting deposition potentials and ion concentrations in the bath. Nickel/cobalt alloys have been electrodeposited from sulfamate, sulfate, and chloride solutions onto Au substrates. The optical properties were monitored in situ with a real-time spectroscopic ellipsometer measuring simultaneously at 44 wavelengths in the 410–750 nm spectral range. In situ measurements have the advantage of determining the material microstructural …

Applying Photovoltaics To Disaster Relief, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

Hurricanes, floods, tornadoes, earthquakes, and other disasters can happen at any time, often with little or no advance warning. They can be as destructive as Hurricane Andrew leaving several hundred-thousand people homeless or as minor as an afternoon thunderstorm knocking down local power lines to your home. Major disasters leave many people without adequate medical services, portable water, electrical service and communications. In response to a natural disaster, photovoltaic (solar electric) modules offer a source of quite, safe, pollution-free electrical power. Photovoltaic (PV) power systems are capable of providing the electrical needs for vaccine refrigerators, microscopes, medical equipment, lighting, radios, …

Measurements Of The Complex Dielectric Constant Of Volcanic Ash From 4 To 19 Ghz, R. J. Adams, Warren F. Perger, William I. Rose, A. Kostinski

Department of Geological and Mining Engineering and Sciences Publications

Dielectric data in volcanic ash at weather radar wavelengths (centimeter range) are extremely sparse and are crucial for radar sensing of ash clouds and for imaging of volcanic terrains. This study extends previous data to include a wavelength range of 1.5–7.5 cm and volcanic ash compositions of 50–75% silica. The real part of the complex permittivity, ε′, of volcanic ash is 6 ± 0.5 (1σ) for all wavelengths. The imaginary part, ε″, ranges from 0.08 to 0.27. Both ε′ and ε″ show higher values at lower SiO2 concentration. It is safe to assume in any weather radar applications that the …

Coupling And Attenuation Of Waves In Plates By Randomly Distributed Attached Impedances, Joseph A. Turner, Richard L. Weaver

Department of Engineering Mechanics: Faculty Publications

The average response of an infinite thin plate with statistically homogeneous attached random impedances is examined. The added impedances, which represent typical heterogeneities that might occur on complex shells, provide light coupling between the extensional, shear, and flexural waves. The mean plate response is formulated in terms of the Dyson equation which is solved within the assumptions of the first-order smoothing approximation, or Keller approximation, valid when the heterogeneities are weak. Scattering attenuations are derived for each propagation mode. It is shown that the attenuation of one wave type due to coupling to another is proportional to the modal density …