Engineering Commons^™

Microwave Transmission Through Laser Irradiated Dielectrics, Ronald Robert Delyser

Electrical and Computer Engineering ETDs

An investigation is made of microwave transmission through two types of dielectrics while being irradiated by a 15 Kw, CO₂ continuous wave laser. The two materials, a high silica ceramic and a fiber­glass laminate, present two different problems for solution of their microwave transmission characteristics while being subjected to high intensity continuous wave irradiation.

The high silica ceramic was found to exhibit a slightly reduced transmission coefficient with an accompanying change in phase delay due to ablation of the material during laser irradiation. As much as -4db loss with a phase delay of +30° is observed at an intensity …

Buckling Of Stiffened Plates And Shells, William De La Garza

Civil Engineering ETDs

The emphasis in this dissertation is the determination of buckling loads on many types of structures. The available solutions are usually written in a complex form that requires large amounts of time in order to find the buckling loads. For stiffened structures the use of finite difference calculus will provide a vehicle for obtaining solutions that are not as complex. In addition, the use of a reasonable approximation for the stiffener behavior allows the solution to be written in closed from. Direct substitution of the elastic and geometric properties of the stiffeners gives the buckling loads. The application of finite …

Affinity Of Roadside Soils For Lead, Zinc, And Chromium, John H. Bell

Retrospective Theses and Dissertations

Highways are known to be a source of several toxic pollutants including the heavy metals lead, zinc and chromium. The need to manage highway runoff in a manner which reduces or eliminates the loading of heavy metals to receiving waters is evident, but more research has been required to develop cost-effective ways of meeting this need. Recent studies have indicated that the soil is a significant "sink" for heavy metals, allowing speculation that management practices which make use of the soil to retain metals from highway runoff should be employed. The purpose of this study is to evaluate the ability …

Sensitivity Analysis Of Stormwater Runoff Using The "Bmp" And "Nonpt" Computer Programs, George D. Flatt

Retrospective Theses and Dissertations

No abstract provided.

Temperature And Time Dependent Viscosity Of An Elastomer Modified Epoxy Resin, Woodrow Williard Wagner Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

Temperature effects on the viiscosity of an epoxy resin (diglycidyl ether of bisphenol A - DGEBA), an elastomer (carboxy terminated butadiene acrylonitrile - CTBN), and two blends containing nominally 10 percent elastomer were examined from strain rates of 0.1 sec^-1 to 10,000 sec-¹ over a temperature range from 300K to 450K. All results indicated the greatest drop in viscosity occurred for each of the materials over the temperature range of 300K to 350K. In addition, the materials exhibited Newtonian responses over the entire strain rate range, Adding small amounts of elastomer to the I epoxy only moderately effected …

The Mining Of Coal In Bristol, Rhode Island: Potential Methodology, Impacts, And Evaluation Of Community Response, Norman Kahn

Marine Affairs Theses and Major Papers

This report addresses the potential commercial mining of coal in the coastal community of Bristol, Rhode Island, with respect to methodology and community response.The attitude of the local community towards any mining proposal will greatly influence the course of development of the resource. In addition, maximum community participation is mandated by both Federal and State law (NEPA and the Rhode Island Coastal Zone Management Act, respectively) (7, 8). It is to be expected that the character of the response will be mediated to a great degree by the expected impacts of the mining operation. For this reason, the methods of …

Studies Of Fracture And Deformed Surfaces Of High Strength Aluminum Alloys By X-Ray Diffraction, Tamma K. Kumar

Mechanical & Aerospace Engineering Theses & Dissertations

X-ray observations of fatigue fracture and deformed surfaces of 7075-T6 aluminum were conducted in this study. The (111) and (222) diffraction peaks were obtained from the fractured and deformed surfaces. It was observed that in comparison with the base metal, the fracture exhibited line broadening similar to that due to cold working. The broadening is indicative of plastic deformation in the vicinity of the advancing crack tip during the fracture process. Also the different regions of fracture exhibited varying degrees of line broadening. With respect to the fatigue crack, the slow crack growth region showed a greater broadening, and, hence, …

Crack Propagation In Aluminum Sheets Reinforced With Boron-Epoxy, George Lawrence Roderick

Mechanical & Aerospace Engineering Theses & Dissertations

The literature has shown that crack propagation in cracked metal sheets can be significantly reduced by bonding an uncracked reinforcement to the metal sheet. However, cyclic debonding typically occurs over a localized area near the crack. Herein, an analysis was developed to predict both the crack growth and debond growth in a reinforced system. The analysis was based on the use of complex variable Green's functions for cracked, isotropic sheets and uncracked, orthotropic sheets to calculate inplane and interlaminar stresses, stress intensities and strain-energy-release rates. An iterative solution was developed that used the stress intensities and strain-energy-release rates to predict …

Analysis Of Moisture Absorption And Diffusion In Fiber Reinforced Polymeric Resin-Matrix Composite Materials, Stephen Stern Tompkins

Mechanical & Aerospace Engineering Theses & Dissertations

The diffusion of moisture through fiber reinforced polymeric-matrix composite materials has been studied analytically. The diffusion in the orthotropic, nonhomogeneous material was modeled, in detail, with a two-dimensional transient diffusion analysis. An effective diffusivity for the composite was determined in terms of the fiber volume fraction and the resin diffusivity. This effective diffusivity is in better agreement with recent data than those previously determined using less complex models.

The influence of both material and environmental parameters on the moisture content of the composite was determined analytically. Predicted moisture contents were compared over a wide range of values for emittance, solar …

A Synchronous Detection System For Dc Resistivity Mapping At The Earth's Surface, Stewart Lee Olsen

Electrical and Computer Engineering ETDs

Current practices in geothermal research require electrical prospecting methods such as resistivity mapping and profiling. This project was predicated on the need for an improved measurement technique for performing dc resistivity mapping at the earth's surface. A synchronous detection system provides automatic detection, recording, and flexible control for the signal current source used in resistivity mapping. As a part of this project, a synchronous detection system was designed, fabricated, and tested. The system incorporates a noise suppression scheme using the frequency-modulated spectrum of the noisy signal. The overall system, which includes a Synchronous Transmitter Control, a Synchronous Detector, and a …

Information Systems For Natural Resources Managers: An Exercise In Interfacing, Connie L. Knapp

Marine Affairs Theses and Major Papers

This thesis proposes guidelines for achieving the human interfaces which are requisite to the development and operation of natural resources information systems. Conclusions were drawn from an evaluation of past experiences in building and attempting to use these types of systems. Both successful and unsuccessful systems were considered, as well as the current effort in Rhode Island to develop a system for coastal resources managers. Examples are presented to support particular conclusions and recommendations. The perspective is nontechnical. Examples and recommendations, therefore, are conceptual rather than quantitative or technical. While a variety of mechanisms can be used to achieve the …

Concrete Ships, Mark L. Lavache

Marine Affairs Theses and Major Papers

The incentive behind this study is based on a two-fold premise: 1) that a comprehensive outline of the historical development of concrete shipbuilding and its related technologies is either non-existent or defies discovery, and 2) that although this study is neither based on a hypothesis, nor intended to resolve a problem area or promote a position, its merit lies in its inductive nature. Included are explanations of of the various compositions, uses, and construction techniques relating to reinforced concrete, ferro-cement, and prestressed concrete.

Metrication In Highway Design And Operations, Taher A. Al-Fadhli

Dissertations and Theses

The complex problem of metrication of highway design, construction and maintenance has been the subject of a number of studies and pilot projects carried out by the Federal Highway Administration (F.H.W.A.) of the United States and the Roads and Transportation Association of Canada. Through a research grant, the FHWA of the U.S.A. assigned the Ohio Department of Transportation, the Illinois Department of Transportation and the Oregon Highway Division to design, construct, and maintain these metric projects. The author has reviewed the experience and conclusions of these studies and the problems encountered in the pilot projects relative to the design, survey, …

Site Selection For Air Pollution Monitoring In The Vicinity Of Point Sources, John C. Brown

Retrospective Theses and Dissertations

Ever since air pollution became a national concern in the 1950's, more and more emphasis has been placed on collection of representative air samples for many purposed, to include (1) evaluation of the degree to which national ambient air quality standards are being met and (2) to monitor maximum emission levels from point sources. Until recently efforts were directed toward qualitative methods of siting monitors for representative sampling. Since the dispersion of effluents is most complex, the quality of the data collected on the basis of judgment and, more or less, incremental siting about the source, has become suspect. Furthermore, …

Investigations Of Inertia Effects On An Infinite Solid Cylinder Due To Thermal Shock, Roland Vanderbilt Williams

Retrospective Theses and Dissertations

In this paper the effects of inertia are explored for the case of a thermal excitation applied on the surface of an infinitely long, solid circular cylinder. The linear uncoupled field equations for a homogeneous, isotropic, thermoelastic medium are used to derive the desired field equations of stress and displacement. The solution procedure included, first, the determination of the thermal boundary value problem from the energy equation which is identically satisfied for the uncoupled condition. Secondly, substitution of the strain-displacement relationships and the previously obtained thermal relation into the equilibrium equation containing inertial effects. The equilibrium equation is the only …

Power Inverters, Ezzatollah. Vahedi-Faridi

Retrospective Theses and Dissertations

This paper treats the theory and basic design of a DC-AC inverter. The output voltage, a periodic wave form, is derived from a low level DC source. The inverter's operation is described in detail for two different classes of switching device: SCR and transistor. A new design configuration which achieves higher efficiency than most commercial inverters on the market is discussed. Laboratory measurements for the design are tabulated in order to give an estimate of its performance.

Analysis Of System Reliability As A Capital Investment, Albert J. Williams

Retrospective Theses and Dissertations

This report, "Analysis of System Reliability as a Capital Investment", is an analysis of radar system reliability of two similar tracking radar systems as a capital investment. It describes the two tracking radar systems and calculates the mission failures rates based upon field failure data. Additionally, an analysis of a simulation program written in FORTRAN is performed which treats system reliability as a capital investment based on 335 electronic systems that were fabricated with a reliability program versus 564 electronic systems fabricated without a reliability program. The data from the two tracking radar systems, one with reliability program and the …

Digital Computer Analysis Of The Kinetic Response Of A Thermal Pressurized Water Reactor Power Plant, John F. Alburger

Retrospective Theses and Dissertations

A digital computer model has been developed to simulate the kinetic response of a thermal pressurized water reactor power plant. The program is capable of predicting core power and plant temperature variations which result from disturbances due to routine demand changes, control rod movement, and fission product poison transients as well as from transients during plausible accident situations. The development of the differential equations describing the influence of various primary plant components on the dynamics of the reactor have been heretofore documented in the literature. Finite difference equations facilitating the employment of a digital computer solution are fully derived. Confidence …

Web Crippling Strength And A Combination Of Bending And Web Crippling Of Cold-Formed Steel Beams, Nipon Hetrakul

Doctoral Dissertations

"The web crippling strength of cold-formed steel beams was investigated experimentally. In this investigation, due consideration was given to the possible influence of bending moment and shear force on the web-crippling loads.

For the subject of web crippling strength, the study involved the testing of 140 built-up beams having single unreinforced webs and 152 I-beams having double webs. In addition, 66 beam tests were conducted for the case of combined bending moment, shear and web crippling.

The experimental results obtained from the beam tests conducted at the University of Missouri-Rolla and the early tests performed previously at Cornell University were …

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 …

Bearing Capacity Of Surface Footings On A Sand Layer Resting On A Rigid Rough Base, Tom Walter Pfeifle

Electronic Theses and Dissertations

The purpose of this study is to present the results of some recent laboratory model testing on the ultimate vertical load carrying capacity of rough, rectangular, surface footings which were placed on granular soil. A rigid base was located at limited depths. It is expected that these results will lend to a better quantitative understanding of the problem.

Treatment Capabilities Of A Rapid Infiltration Pilot Unit Treating Stabilization Pond Effluent, Richard G. Seas

Electronic Theses and Dissertations

In October, 1972, Congress passed PL 92-500, "Federal Water Pollution Control Act Amendments of 1972 1; which is designed to upgrade the quality of the nation's water. The act requires the formulation of effluent standards that would require use of “best practicable treatment”. The effluent standards are to require use of the "best available" technology by July 1, 1983 (1). PL 92-500 requires the Environmental Protection Agency Administrator to publish information explaining which treatment techniques may be used to meet the requirement of "best practicable treatment". Land application of wastewater has been designated as a viable alternative to traditional treatment …

An In-Plant Waste Survey Of An Egg-Processing Plant, James R. Schultz

Electronic Theses and Dissertations

The total number of eggs produced.in the United States has increased from 40 billion in 1940 to approximately 70 billion in 196 7 (1-265). It is expected that the demand for processed eggs will increase from ten percent of the total production in the 1960's to over 30 percent in the 1970's (2-805). The increase in use of processed eggs will undoubtedly result in an increase in production wastes. To estimate the water pollution potential of egg wastes and to provide the information necessary for procurement of waste discharge permits, knowledge of the volume, strength and treatability of egg-processing wastes …

Application Analysis Of A Cellular Geographic Information System, Michael Edward Wehde

Electronic Theses and Dissertations

AREAS, the Area REsource Analysis System, was developed by the author as an analytical tool for resource data manipulation in a spatial context. The data base and processing software design factors relevant to economical application are reviewed. The investigation seeks to define a procedure for selection and justification of the grid cell size used to quantify the spatial domain. The performance of a cellular information system is measured in terms of mapping and inventory accuracy. These measures of performance are evaluated for various cellularizations of a single map. The interboundary distance distribution is justified as the only unique characterization of …

The Effect Of Potassium Permanganate On The Removal Of Iron And Manganese From Ground Water, Mohammad Reza Farvardin

Electronic Theses and Dissertations

For the past three years or so, a gradual migration of iron and manganese deposits has been observed in the water mains to the west of the East Water Treatment Plant of Brookings, South Dakota. These deposits have been gradually migrating further westward from the plant (8). Routine analyses of the treated water from the East Plant indicate that the iron and manganese levels are within the USPHS recommended limits (9). Consequently, conclusive evidence that this plant is the source of the problem does not exist. However, the analyses are normally conducted on samples collected shortly before backwashing the filters. …

Discharge Measurement And Energy Efficiency Evaluation Of Irrigation Pumping Plants, Bruce A. Jennings

Electronic Theses and Dissertations

No information has been available regarding efficiencies of electric irrigation pumping plants in South Dakota. Pumping plant discharge, a key parameter in the calculation of pumping plant efficiency, is often difficult to measure in the field. A project was initiated at South Dakota State University in 1976 to investigate field pumping plant efficiencies. The following objectives were established for the project. 1. To investigate various methods of measuring irrigation pumping plant discharge. 2. To develop a suitable field procedure for determining electric irrigation pumping plant efficiency. 3. To measure energy efficiency of selected electric irrigation pumping plants in South Dakota.

A Hydrologic Analysis Of The Meramec River Basin, Missouri, Glendon Taylor Stevens Iii

Masters Theses

"The purpose of this study was to develop water budgets for the Meramec River Basin. These budgets, developed from average annual data, are quantitative assessments of the basin's water resources.

On a long-term basis, inflow was approximately balanced by outflow indicating that the system is steady state.

Precipitation was found to be the only substantial source of inflow to the basin and averages about 40 inches per year.

Evapotranspiration was found to be the major source of outflow from the basin. Annually it accounts for about three quarters of the total outflow and averages about 30 inches.

Streamflow was found …