Engineering Commons^™

Polarimetric Characterization Of Random Electromagnetic Beams And Applications, Mircea Mujat

Electronic Theses and Dissertations

Polarimetry is one of the principal means of investigating the interaction of light with matter. Theoretical models and experimental techniques are presented in this dissertation for polarimetric characterization of random electromagnetic beams and of signatures of random media in different scattering regimes and configurations. The degree of polarization rather than the full description of the state of polarization is of interest in multiple scattering and free space propagation where the statistical nature and not the deterministic component of light bears the relevant information. A new interferometric technique for determining the degree of polarization by measuring the intensity fluctuations in a …

Quadratic Spatial Soliton Interactions, Ladislav Jankovic

Electronic Theses and Dissertations

Quadratic spatial soliton interactions were investigated in this Dissertation. The first part deals with characterizing the principal features of multi-soliton generation and soliton self-reflection. The second deals with two beam processes leading to soliton interactions and collisions. These subjects were investigated both theoretically and experimentally. The experiments were performed by using potassium niobate (KNBO3) and periodically poled potassium titanyl phosphate (KTP) crystals. These particular crystals were desirable for these experiments because of their large nonlinear coefficients and, more importantly, because the experiments could be performed under non-critical-phase-matching (NCPM) conditions. The single soliton generation measurements, performed on KNBO3 by launching the …

Stable Spatial Solitons In Semiconductor Optical Amplifiers, Erdem Ultanir

Electronic Theses and Dissertations

A spatial soliton is a shape invariant self guided beam of light or a self induced waveguide. Spatial solitons appear as a result of the balance of diffraction and nonlinear focusing in a system. They have been observed in many different conservative media in the last couple of years. Solitons are ubiquitous, because of the probability of using their interactions in optical data processing, communications etc. Up to now due to the power required to generate the solitons, and the response times of the soliton supporting media, these special waves of nature could not penetrate the applications arena. Semiconductors, with …

Dispersion-Managed Breathing-Mode Semiconductor Mode-Locked Ring Laser, Bojan Resan

Electronic Theses and Dissertations

A novel dispersion-managed breathing-mode semiconductor mode-locked ring laser is developed. The "breathing-mode" designation derives from the fact that intracavity pulses are alternately stretched and compressed as they circulate around the ring resonator. The pulses are stretched before entering the semiconductor gain medium to minimize the detrimental strong integrating self-phase modulation and to enable efficient pulse amplification. Subsequently compressed pulses facilitate bleaching the semiconductor saturable absorber. The intracavity pulse compression ratio is higher than 50. Down chirping when compared to up chirping allows broader mode-locked spectra and shorter pulse generation owing to temporal and spectral semiconductor gain dynamics. Pulses as short …

Towards Direct Writing Of 3-D Photonic Circuits Using Ultrafast Lasers, Arnaud Zoubir

Electronic Theses and Dissertations

The advent of ultrafast lasers has enabled micromachining schemes that cannot be achieved by other current techniques. Laser direct writing has emerged as one of the possible routes for fabrication of optical waveguides in transparent materials. In this thesis, the advantages and limitations of this technique are explored. Two extended-cavity ultrafast lasers were built and characterized as the laser sources for this study, with improved performance over existing systems. Waveguides are fabricated in oxide glass, chalcogenide glass, and polymers, these being the three major classes of materials for the telecommunication industry. Standard waveguide metrology is performed on the fabricated waveguides, …

Design And Development Of A Lubrication Pump For A Horizontally Mounted Air-Conditioning Compressor., Kenneth T. Gilbert

Electronic Theses and Dissertations

Horizontally mounted compressors offer the advantage of reduced height in central air-conditioning units but prove difficult to produce economically due to costs associated with the manufacture of acceptable lubrication systems for the compressors. This study develops an effective, affordable oil pump for use on a horizontal compressor. Concepts are proven through testing of prototype assemblies. Test results drive modifications for future prototypes, and prototypes demonstrating adequate performance are modified for ease of manufacture.

Research in this study proves that the most suitable design results from a modification of a rotating vane pump. The pump’s modifications enable it to pump oil …

Modeling Sugarbeet Quality Variables From Satellite Images And Canopy Spectral Indices, Subodh Kulkarni

Electronic Theses and Dissertations

Remote sensing was used to model crop quality from measurements of canopy spectra. Three indices of canopy characteristics, derived from satellite image data, were tested for relationship to whole-field sugarbeet quality. Quality was quantified as recoverable sucrose per ton of harvested sugarbeets. Quality data were extracted from the year 2002 Field Database of the Southern Minnesota Beet Sugar Co-operative, (SMBSC), Renville, Minnesota. Linear regression models utilizing canopy indices and changes in canopy indices over time were tested for relationship to sugarbeet quality for four classes of sugarbeets. Classes of sugarbeet tested represented fields planted to a mix of varieties resistant …

Effects Of Temperature, Water Hardness, And Recirculation On Copper Corrosion, Brian R. Weiss

Electronic Theses and Dissertations

In previous work, the effects of water quality have been shown to influence the formation of scale from copper corrosion. A general understanding of the effects of water quality on copper corrosion have been difficult to obtain because of complex interactions of water quality variables on copper corrosion in different water supply systems. The objective of this study was to examine the effects of temperature and water hardness on copper corrosion occurring in a household water supply system. The effects of recirculation were also studied in concurrence with the above water quality parameters. Electrochemical corrosion testing and corrosion by -product …

Design Modification And Optimization Of The Interior Ballistics For An Existing Naval Gun System., Gregory Allen Dennison

Electronic Theses and Dissertations

This thesis determines the physical, chemical and thermodynamic properties of an advanced solid propellant that can be used in the proposed upgrade of the Navy's 5-inch, Mark 45 gun system to achieve a muzzle energy of 14.928x16^6 ft-lbf (20.24 mega Joules(MJ)) firing a proposed 110 pound Precision Guided Munition (PGM). This energy level corresponds to an 95% increase over the current system that uses Navy Cool, or NACO, solid propellant and a 70 pound projectile. The propellant properties were parameterized using the interior ballistics simulation code known as Interior Ballistics of High Velocity Guns - 2 (IBHVG2), version 505D. The …

Preprocessing Of Microcirculatory Images., Mohamed S. Mansour

Electronic Theses and Dissertations

This thesis project consists of the development of a computerized image processing system to preprocess microvascular images of the mouse Latisimus Dorsi Muscle (LDM). This research has been conducted in association with the Division of Plastic and Reconstructive Surgery at the University of Louisville. The input to the system is a set of 35 or more overlapping microscopic fields or sub_images containing segments of the LDM microcirculation, the output is an adjacent single montage encompassing the entire LDM microvasculature. The developed system presents practical solutions to the problems of image registration, overlap resolution, and image segmentation, in addition, the results …

Development Of Stereoscopic Particle Tracking Velocimetry For Turbulent Flow Field Diagnostics, Veera P. Rajendran

Electronic Theses and Dissertations

Stereoscopic particle tracking velocimetry (SPTV) was used to analyze a turbulent submerged jet of Reynolds number (based on the diameter of the nozzle) 8000. SPTV involves tracking the motion of tracer particles over time in a flow in three dimensions. The first part of this work consisted of developing a stereoscopic particle tracking technique using two high-speed video cameras. This included calibration of the cameras with "known" points, and developing an algorithm to automatically match and track particles. The second part was to apply the same to a submerged water jet in order to measure velocities. The velocities were subsequently …

Nitric Oxide Production: A Mechanism For Inhibition Of Chlamydia Trachomatis Replication, Bojun Chen

Electronic Theses and Dissertations

Chlamydia trachomatis (CT) replicates in macrophages, but is inhibited by IFN-$\gamma$ or LPS. IFN-$\gamma$ and/or LPS induced nitrite production in mouse peritoneal macrophages, macrophage cell lines (RAW264.7 and J774A.1) and McCoy cells. Kinetic studies indicated that peak production occurred 48 hours post-treatment. CT infection itself was insufficient to induce nitrite production, but resulted in enhancement of nitrite production in IFN-$\gamma$-treated cells. Treatment with IFN-$\gamma$ or LPS resulted in significant inhibition of CT replication in these cells. Strong correlation between nitrite production and inhibition of CT replication was observed in RAW264.7 and J774A.1 cells (correlation coefficients: $-$0.93 and $-$0.94, p $<$ 0.001). N$\sp{\rm g}$- monomethyl-L-arginine (L-NMMA) specifically inhibited nitrite production and partially reversed inhibition of CT replication in macrophage cell lines. NOS mRNA was measured in RAW264.7 cells by Northern blot and Dot blot hybridization. Strong correlation between NOS mRNA expression and inhibition of CT replication (correlation coefficient: $-$0.97, p $<$ 0.05) was observed. Anti-TNF-$\alpha$ antibody completely neutralized the biological activity of TNF-$\alpha$ secreted by LPS-treated RAW264.7 cells, yet the antibody neither reduced nitrite production nor restored CT replication. Combination of the antibody and L-NMMA significantly enhanced restoration of CT replication. In peritoneal macrophages, inhibition of CT replication induced by IFN-$\gamma$ was partially restored by L-NMMA or anti-TNF-$\alpha$ antibody. In McCoy cells, inhibition of CT replication induced by IFN-$\gamma$ and LPS was not significantly restored by L-NMMA. Great restoration of CT replication by 1 mM L-NMMA was observed in LPS-treated J774A.1 cells (31%), but not in IFN-$\gamma$-treated cells (5%). Our data indicate that (1) NO production is one of the mechanisms for inhibition of CT replication in IFN-$\gamma$-activated peritoneal macrophages and RAW264.7 cells; (2) NO plays a significant role in CT inhibition in LPS-treated macrophage cell lines, but not peritoneal macrophages; (3) TNF-$\alpha$ may be associated with inhibition, but the mechanism(s) may not involve NO production; (4) NO production may not be the mechanism for CT inhibition in McCoy cells treated with IFN-$\gamma$ and LPS.

Proposed Smoothing Technique To Avoid Numerical Instabilities In A Hydrodynamic Numerical Model, Thomas P. Abraham

Electronic Theses and Dissertations

Despite every effort being made to produce a completely problem-free computational model, no breakthrough has yet been made. When a numerical model is used to solve a real world problem, there is a tendency for the non-physical spurious waves to creep in. If these waves are not checked, they can lead to serious instability problems. Once these waves are removed, the model should be able to simulate physical phenomenon like circulation, separation, flow reversal in the vertical plane, mixing/transport, convection/diffusion, etc.

When a numerical mode] is made to run for a certain period of time, node-to-node oscillations may arise and …

The Development Of A Solar Radiation Extinction Correction For Satellite Data, Widad I. Mohamed

Electronic Theses and Dissertations

The main objectives of this thesis are the following: 1) Remove the haze using water surfaces in Landsat satellite imagery of the visible and near-infrared regions for their properties of high absorption of solar radiation and weak reflection of it. The scattered solar radiation is most obvious in dark weakly reflecting regions such as water. The haze removal technique depends on subtraction of scattered light from picture elements within the satellite imagery. 2) Derive a formula and techniques for a given image to correct for extinction by transforming the observed intensity of the signal transmitted to the Landsat detector to …

Metabolism Of Arachidonate-Containing Phospholipid Molecular Species In The Murine Macrophage-Like Cell Line, P388d1, Crystal R. Waites

Electronic Theses and Dissertations

Glycerophospholipids of mammalian cells exist as chemically diverse structures with various fatty acids at the sn-1 and sn-2 positions. Arachidonic acid, a polyunsaturated fatty acid, which may be converted to biologically active eicosanoids such as prostaglandins, thromboxanes, and leukotrienes, is found predominantly in the sn-2 position of glycerophospholipids. The purpose of this study was to examine, at the level of the individual molecular species, the incorporation of arachidonate into phospholipids and its release from phospholipids during stimulation. In this way, the specificity of the enzymes controlling arachidonate metabolism could be examined in order to clarify the processes that control the …

Spatial Control Of Crop Inputs Via Laptop And Typical Field Travel, Joseph Alan Schumacher

Electronic Theses and Dissertations

Field Grid Sense (FGS) is a system developed for use with a laptop computer to control crop production inputs. FGS can be used for spatially controlling and recording field inputs according to regional requirements within the field. Location is identified via the travel lanes formed during field operations. Grid areas within lanes are formed by measuring from the beginning of each lane to the start of each grid within the lane. Distance measurements are reset at the beginning of each lane in order to eliminate accumulated distance error in the field. A fifth wheel, which runs in the smooth path …

Design And Applications Of A Graphics Package For The Hp1000 Computer., Hsiao-Chih George Lee

Electronic Theses and Dissertations

The objective of this thesis is to develop the FORTRAN subroutine PLOTER which is a general-purpose plotting tool to plot charts on a Hewlett Packard plotter. The programs RESP and INVLAP which can plot the frequency and time responses of system functions are modified to adopt the PLOTER subroutine and are stored of the HP1000-A900 minicomputer whose software, the GRAPHICS/1000, supports the graphics ability of PLOTER. This thesis describes the theories, functions, software techniques and operations of the PLOTER subroutine and the application programs RESP and the INVLAP. It also provides program listings and example plots.

A Loran-C Antenna Coupling Unit., Timothy Andrew Reilly 1963-

Electronic Theses and Dissertations

This project is the design of an antenna-coupling unit (ACU) that will operate with the Texas Instruments LORAN-C receiver and a 28-inch antenna. The height of the antenna used at the present is eight feet. Since the application of LORAN-C positioning is being expanded to vehicular location, an eight-foot antenna is not practical. The shorter antenna is necessary to prohibit striking trees, overpasses, etc. The newly designed ACU has more voltage gain to compensate for the attenuation of the incoming signal due to the shortening of the antenna. It also has a bandpass of 90 KHz-110 KHz with the center …

A Master Clock For The Speed School Impulse Clock System Using Wwv Time Information, John E. Pfeifer Jr.

Electronic Theses and Dissertations

Since approximately February of 1979, the Speed School impulse clock system has not functioned due to a worn-out master clock that was never replaced because of a lack of fund. For this thesis project, a solid-state master clock that performs the same functions as the old mechanical master clock was built for less than $200. The new clock features accuracy traceable to the National Bureau of Standards, automatic reset after a power-down and subsequent power-up, and a daylight savings time provision. A decoder that recovers time information broadcast by radio station WWV from Fort Collins, Colorado was built and interfaced …

Performance And Evaluation Of A Variable-Speed Darrieus Wind Turbine, Kasey W. Abbott

Electronic Theses and Dissertations

Developing wind energy suitable for agriculture applications is a critical step towards providing a reliable, affordable energy supply for United States agriculture. United States agriculture, due to its energy intensive nature-, is dependent on petroleum fuels. Because agriculture is extremely sensitive, to supply interruptions, steps must be taken to reduce this dependence on oil, including developing wind energy systems. It appears that the potential is there since winds over the United States contain more than 30 times the total energy consumed in this nation (Soderholm, 1979).
Agricultural applications (e.g. irrigation pumping, product processing and building heating) are uniquely suited to …

Probable Causes Of Cracking In A Series Of Reinforced Concrete Box Girder Bridges, Steven Milton Bjordahl

Electronic Theses and Dissertations

This thesis is the result of a study undertaken at the request of the South Dakota Department of Transportation (SDDOT) to determine the probable cause of a specific type of cracking that was observed in a series of reinforced concrete box girder bridges. The cracking consists of horizontal cracks through the end diaphragms of the girder and horizontal cracking over the interior bents. Typical crack patterns obtained from information supplied by the SDDOT are shown in Figure 1.

Ozonation Of A Municipal Groundwater Supply To Reduce Iron, Manganese, And Trihalomethane Formation, Richard Alan Stoebner

Electronic Theses and Dissertations

The purpose of this investigation was to determine the feasibility of using ozonation followed by filtration for removal of iron and manganese and prevention of trihalomethane formation. To avoid disruption of the treatment plant operation, pilot-scale units were used in the investigation. The filter media and filtering rates employed during the pilot studies were identical to those used at the East Water Treatment Plant.

Petrology Of North Mississippi Bauxite : A Case For Depositional Bauxite And Kaolin, Charles Nelson Thompson

Electronic Theses and Dissertations

In the past 55 years, there has been considerable debate over the stratigraphic position, genesis, and economic value of North Mississippi bauxite. The aluminum rich deposits are unlike most deposits found around the world. The deposits are associated with 200-300 foot thick marine to nonmarine clays overlain by feldspar poor, fluvial-deltaic sediments. The possible source areas are composed of limestone, marls, sand, and muds ranging in age from Late Cretaceous to Late Paleocene. These factors prohibit the direct application of previous theories derived from studies outside Mississippi. The deposits, therefore, cannot be considered a textbook example of bauxite formation.

To …

Performance And Evaluation Of Swine House Heating With A Solar Energy Intensifier-Thermal Energy Storage System, Albert J. Heber

Electronic Theses and Dissertations

The urgency for energy independence in the United States is unprecedented in its history. The demand for energy is reflected in rising fuel costs which affects every segment of the economy. Among the most severely affected sectors is the agriculture industry, whose fossil fuel consumption is crucial to its efficient production of food and fiber. Solar, one of several alternative energy sources being developed nationwide has unique possibilities in the U.S. agriculture system. Large areas are available for locating collector units, and the energy requirements in the farm are low compared with the available radiation falling on the area. Drying …

Design Of A Vertical Axis And Turbine-Variable Speed Heat Pump Alternate Energy System, John V. Karnitis

Electronic Theses and Dissertations

The primary objective if the project is to design an unguyed wind energy conversion system consisting of a Savonius rotor assisted non-articulating 5m (15 ft) diameter Darrius vertical axis wind turbine, which is self-starting, and is mechanically coupled by a V-belt drive to an automotive air conditioning variable speed compressor. The variable speed-compressor is utilized as a mover for a variable speed heat pump system. The basic objective is further subdivided into the following objectives:
1. To develop a preliminary design of the wind energy conversion system, which later cane be modified to the existing energy needs.
2. To predict …

Design And Performance Of A Solar Energy Intensifier System For Drying Shelled Corn, Kenneth J. Hellevang

Electronic Theses and Dissertations

Since utilizing solar energy as an alternate energy source for agricultural applications is dependent on improvement in the design of solar systems and on documentation of the performance characteristics, reliability and economic feasibility of solar systems, research was conducted with the following objectives: 1. Design a multi-purpose solar energy system with a diurnally tracking solar energy intensifier and a thermal energy storage unit to warm the ventilation air for a swine confinement building and to dry corn. 2. Test the solar energy intensifier-collector system for corn drying under actual conditions. 3. Evaluate the performance and economic feasibility of a diurnally …

The Practicality Of The Caldwell-Lawrence Diagrams For Predicting Lime-Softened Water Quality, James A. Arndt

Electronic Theses and Dissertations

The objectives of the investigation were: 1.) to determine the validity of the Caldwell-Lawrence diagrams in predicting alkalinity, calcium, and pH values at various levels of lime addition of the softening process. 2.) to determine the practical application of the diagram for plant operators in daily operations and design engineers for design calculations. Throughout the investigation, primary consideration was given to the practical aspects of water treatment in terms of water sampled, methodology, and.statistical analysis of test results. Construction of the Caldwell-Lawrence diagrams is based on chemical equilibrium between the carbonic species and calcium and magnesium in water. The theory …

Bearing Capacity Of Eccentrically Loaded Surface Footings On A Sand Layer Resting On A Rough Rigid Base, Roland Dale Maynard

Electronic Theses and Dissertations

The purpose of this investigation is to present the results of some recent laboratory model testing of the ultimate load carrying capacity of eccentrically loaded strip, surface footings on sand, with a rigid base located at varying depths. It is expected that these results will. lend to a better quantatative [sic] understanding of the problems encountered in these situations.

Ground Water Quality Variation At A Rapid Infiltration Land Treatment System Used For Tertiary Wastewater Treatment, Thomas W. Drake

Electronic Theses and Dissertations

Based on the need to monitor nitrates because of the 1977 modifications, as well as upon the original EPA provisions for ground water monitoring, the studies reported in this thesis were initiated. The objectives of this investigation were as follows: 1. To monitor four wells within the influence of the rapid infiltration pilot units, as well as two control wells located beyond the influence of the units, to determine any substantial changes in ground water quality, which might be attributed to the rapid infiltration pilot unit operation; 2. To specifically examine the nitrogen data collected from the perforated drains in …

Comparison Of Theoretical And Experimental Results Pertaining To R-Curves In Low And High Ductility Solids, Rabindra Nath Dash

Electronic Theses and Dissertations

Existing linear elastic fracture mechanics and J-integral analyses are well suited for safety assessments of high-strength, low-toughness materials. These analyses apply only to the onset of crack growth, which is usually tantamount to crack instability and structural failure in that class of materials. However, this is not the case for the low-strength, high-toughness materials in which crack instability may be preceeded [sic] by extensive stable crack growth under rising loads. Here, a substantial margin of safety may exist even when the onset of crack growth is imminent. This thesis describes research leading to a ductile fracture-mechanics methodology designed to treat …