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Watershed, Hydrodynamic, And Water Quality Models For Total Maximum Daily Load St. Louis Bay Watershed Mississippi, Noor Baharim Hashim

Theses and Dissertations

In the development of the watershed, hydrodynamic, and water quality models for St. Louis Bay in Mississippi, the Better Assessment Science Integrating Point and Nonpoint Sources (BASINS 2.0) - Nonpoint Source Model (NPSM) was selected as the watershed model and the Environmental Fluid Dynamics Code (EFDC) which includes hydrodynamic and water quality models was selected as the Bay model. Watershed model calibration was initially accomplished utilizing historical data collected by the U.S. Geological Survey (USGS), U.S. Environmental Protection Agency (USEPA), Mississippi Department of Environmental Quality (MDEQ), and Gulf Coast Research Laboratory (GCRL). The watershed model simulated nonpoint source flow and …

Human Thermal Comfort, Kien Khanh Huynh

Theses and Dissertations

The purpose of this research is to investigate human comfort criteria under steady-state conditions as a function of ambient air temperature, mean radiant temperature, relative humidity, air velocity, level of activity, and clothing insulation. Since the current ASHRAE Standard 55-1994 is for sedentary activity, this study will consider relative humidity (20% to 65%), dry bulb temperature (73 oF to 82 oF), air velocity (30 fpm and 50 fpm), and sedentary-to-moderate activity. The mean radiant temperature will be taken to be the same as the ambient air temperature. The experimental results collected at the Kansas State University Environmental Test Chamber are …

Effects Of Pressurization On Aluminum 319 And A356.2 Alloy Castings, Sharolyn Gales

Theses and Dissertations

Castings made of aluminum 319 and A356.2 alloy were examined to determine the effectiveness of using pressure application during solidification to reduce porosity levels. Pyknometry was the method chosen to measure porosity. It was determined that the porosity of castings poured in both alloys was reduced in some instances. During the study, the surfaces of these castings were also examined and some were found to have defects present. After the porosity was evaluated, specimens of castings poured in both alloys were tested to determine whether or not the surface intrusions affected the castings. The defects were found to reduce the …

Boiling Heat Transfer In Horizontal Micro-Fin Tubes, Soon Seng Tang

Theses and Dissertations

Two existing evaporation two-phase heat transfer models are validated using 526 experimental data points for pure refrigerants and refrigerant mixtures. The Kido et al. (1995) model fails to predict pure refrigerant data sets except their R22 experimental data set. The Cavallini et al. (1999) model successfully predicts the available R22 data sets; however, the model over-predicts the R12 and the R134a data sets. In addition, the Cavallini et al. (1999) mixture model fails to predict the available 155 refrigerant mixture data points. The proposed modified model, based on the Cavallini et al. (1999) model, successfully predicts the experimental data for …

Overlapping Of Communication And Computation And Early Binding: Fundamental Mechanisms For Improving Parallel Performance On Clusters Of Workstations, Rossen Petkov Dimitrov

Theses and Dissertations

This study considers software techniques for improving performance on clusters of workstations and approaches for designing message-passing middleware that facilitate scalable, parallel processing. Early binding and overlapping of communication and computation are identified as fundamental approaches for improving parallel performance and scalability on clusters. Currently, cluster computers using the Message-Passing Interface for interprocess communication are the predominant choice for building high-performance computing facilities, which makes the findings of this work relevant to a wide audience from the areas of high-performance computing and parallel processing. The performance-enhancing techniques studied in this work are presently underutilized in practice because of the lack …

Microbiotic Assessment Of An Upflow Anaerobic/Aerobic Swine Treatment Process, Robert Earl Mcclain

Theses and Dissertations

Confined animal feeding operations (CAFOs) relating to swine and their resulting odors continues to be an issue of concern. The primary sources of odors from a CAFO include general ventilation of the confinement house, the anaerobic lagoon, and the land application of lagoon sludge. This paper focuses on lagoon wastewaters, but the results therein could have influence on the other two aforementioned areas. An advanced upflow anaerobic/aerobic reactor system was developed to determine its impact on microbial activities that ultimately result in offensive odors. The microbial activity of SRB (sulfate-reducing bacteria) and hydrogen-sulfide production was monitored closely in each ?zone?, …

Watershed Based Analysis For Water Quality Management Within The Escatawpa River System, Gerrod Wayne Kilpatrick

Theses and Dissertations

Assessment of water quality within the Escatawpa River system was accomplished utilizing the Better Assessment Science Integrating Point and Nonpoint Sources (BASINS 2.0) to develop the watershed model, and the CE-QUAL-W2 software to develop the estuary model. The watershed model was utilized to quantify both hydrodynamic and water quality (fecal coliforms) characteristics of the watershed for a simulation period spanning from 1990 through 1999. Herein, calibration and application results are presented for watershed and estuary simulations made in an uncoupled manner. The models were developed such that loose coupling of watershed and estuary models can be accomplished as a subsequent …

A Process For Hydrogenation Of Silicon Carbide Crystals, Yeswanth Lakshman Rao

Theses and Dissertations

Doping control is the most important technology for any semiconductor system. In spite of significant progress in the doping of SiC, advancements are needed in the growth techniques and dopant incorporation. During processes such as Chemical Vapor Deposition (CVD), hydrogen is known to be trapped at defects or impurities and to alter the electrical properties of the material. This effect is known as ?hydrogen passivation?. In addition to the observed hydrogen passivation of shallow impurities in SiC crystals, it is important to know whether, and how, hydrogen present in the epi ? reactor can passivate doping impurities during growth of …

Characterization Of Fatigue Crack Propagation In Aa 7075-T651, Robert Blandford

Theses and Dissertations

To better design structures and machines, understanding of flaws and failures is essential. The body of this work has addressed numerous facets of fatigue crack propagation. The affect of crack closure, testing errors, and data scatter are a few important components of crack growth developed and investigated. It was found that the widely accepted compliance-offset technique for closure measurement may be sensitive to increases in load ratio. Opening load uncertainty was calculated to be on the order of 5%. The application of practical regression techniques and the use of DKeff were used to characterize closureree crack growth data to develop …

Development Of The Williams Work Estimator (W2e): A Tool For Determining The Most Effective Match Between Worker Capabilities And Job Task Requirements, Sabrina Natasha Williams

Theses and Dissertations

Demographics indicate that the United States and many other industrialized nations are currently experiencing what is called the ¡°graying¡± of the workforce (Hayslip & Panek, 1993). Today the majority of the workers in many companies are in the age groups of 40-44 and 45-49 years. However, by the year 2010, the largest proportion of workers will probably be in the age groups of 55-59 and 60-64 years (Ilmarinen, 1995). Thus, a growing concern of employers in the near future will be the assignment of older workers to specific job tasks and responsibilities (Williams & Crumpton, 1996) as well as other …

Application Of Remote Sensing For The Prediction, Monitoring, And Assessment Of Hazards And Disasters That Impact Transportation, Tai-Chi Wu

Theses and Dissertations

Although remote sensing has been used in predicting, monitoring, and assessing hazards and disasters for over 50 years, its use in the transportation domain is still in its infancy. This study was conducted to identify the research needs involving the use of remote sensing for such applications within the transportation domain. The first step taken was to determine the current state of remote sensing applications in the transportation domain associated with the prediction, monitor, and assessment of hazards and disasters. The second step was to identify the impacts that such events may cause and the information needed to prevent or …

An Investigation Of Flux-Splitting Algorithms For Chemically Reacting Flows, Rajasekhar Venkata Darapuram

Theses and Dissertations

This paper presents an investigation of seven different flux splitting algorithms for the discretization of inviscid fluxes, which are the primary source for the non-linear behavior (eg. shocks, contact discontinuities). The aim of the present work is to enhance the accuracy and robustness of CHEM, a three-dimensional flow solver, which is capable of simulating a wide range of flow conditions, including chemical non-equilibrium. Five different test cases cases are considered and thoroughly analyzed. The overall goal is to find a numerical scheme that can meet some stringent specifications of efficiency, accuracy and robustness on the widest possible spectrum of flow …

A Numerical Study Of The Conjugate Conduction-Convection Heat Transfer Problem, Robert Samuel Webster

Theses and Dissertations

This study investigates some of the basic aspects of conjugate, or coupled, heat transfer problems. The ultimate interest is in the improvement of an existing computational fluid dynamics (CFD) code by the inclusion of such a coupling capability. Many CFD codes in the past have treated the thermal boundary conditions of a bounding solid as the simple cases of either a surface across which there is no heat flux, or as a surface along which the temperature is a constant with respect to both space and time. These conditions are acceptable for some applications, but many real-world problems require a …

Analysis Of Bell Hole Morphology And Distribution: A Tool For Evaluating Formational Processes, Toby Joseph Dogwiler

Theses and Dissertations

Bell holes are described as vertical, cylindrical, dissolutional cave ceiling voids. Quantitative analysis of bell holes in San Salvador, Bahamas; Isla de Mona, Puerto Rico; Kentucky; and New York permit bell hole morphology to be contrasted in various geological settings and speleogenetic regimes. Mean bell hole height is 36 cm with a width of 34 cm and cross-sectional area of776 cm 2. Bell holes have elliptical openings, conical to cylindrical profiles, strong vertical development, and sometimes are associated with bell pits. Bell hole width remains constant between the study localities, but height varies. Several processes have been proposed to explain …

Impact Of Changes In Ocean Freight Rates On United States Rice Exports, Jorge Alfonso Alarcon

Theses and Dissertations

The direction and magnitude of the future world rice market is of vital consideration for the rice industries of both exporting and importing countries. Many studies have analyzed the international rice trade; however, there has been no published research that attempted to examine the effects of ocean freight rates on international rice trade. The major objective of this study was to analyze the effects of ocean freight rates on the flows, supplies, demands, and prices of world rice shipments. A reactive programming model, within a spatial equilibrium analysis framework, was developed to obtain equilibrium level estimates of the variables mentioned …

Problems And Limitations Of Long-Term Timberland Leases For Non-Industrial Private Landowners, Stephen M. Butler

Theses and Dissertations

Over seven million acres of non-industrial private forest land are controlled by the forest industry under long-term lease agreements. While many landowners appear to be content with these arrangements, others are dissatisfied. Landowners should be aware of the potential benefits, problems, and costs of the long-term commitments.

Hospital-Community Relations In Rural County, Mississippi, Vaughn Leroy Grisham Jr.

Theses and Dissertations

The objective of this study was to describe hospital-community relations in Rural County, Mississippi and to discover those factors which were related to the choice of a hospital by the respondents. Data for the study came largely from personal interviews with 150 rural white housewives. Additional data were obtained from interviews with the physicians, hospital administrator, board or trustees, and hospital auxiliary.

The study began with a description of the hospital situation in the county, this included the acceptance of the county hospital by the community, and the satisfaction expressed concerning the services of the hospital.

The major part of …