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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Comparison of biomonitoring techniques for evaluating effects of jet fuel on bluegill sunfish (Lepomis macrochirus)

Doane, Thomas R. January 1984 (has links)
The purpose of this study was to compare the simultaneous effects of the water soluble fraction (WSF) of JP-4, a common military and civilian jet fuel, on survival, ventilatory rate, preference-avoidance behavior, and blood enzymes and ions of the bluegill sunfish (Lepomis rnacrochirus) to determine possible interrelationships and which procedures might be most descriptive of sublethal stress. The dynamic 96-h LCSO for WSF JP-4 was 26.2% (percent of the maximum soluble amount of JP-4). A concentration of 5.1% WSF JP-4 caused a detectable shift in ventilatory functions (rate and amplitude); this concentration was equivalent to the 96-h LCOl. Fish did not display a strong preference-avoidance reaction when exposed to WSF JP-4. Some avoidance occurred at 3.5% and 4.9% WSF JP-4. At concentrations near the 96-h LCSO fish appeared to lose their ability to detect WSF JP-4, indicating potential for fish not to avoid lethal levels of WSF JP-4. Few significant changes in whole and serum blood parameters were measured in fish exposed to 13% WSF JP-4; at near lethal concentrations changes were primarily attributed to osmoregulatory failure. Therefore such changes in blood parameters would not be useful to validate or confirm exposure to WSF JP-4. There were few significant changes in gill and liver histology of fish exposed to WSF JP-4 other than an increase in size or number of lipid vacuoles in the liver of exposed fish. / Ph. D.
12

Análise da micromedição do volume de água potável domiciliar e sua influência no cálculo das perdas no sistema de distribuição / Micro-measurement of domestic drinking water volume and its influence on the calculation of losses in the distribution system

Borges, Elsio Júnior Bonati 29 August 2007 (has links)
The accelerated degradation of natural hydric resources, along with the increasing demand for drinking water, urge for programs which deal with the losses of this essential good, and that are essential for environmental managers. This work is inserted in this context, with the objective of evaluating the magnitude of the measurement error of the hydrometers installed in Uberlândia-MG, when subjected to consumption variations. There have been comparisons of the equipment commonly used with systems that are more sensible to the measurement of low flows, in order to verify the reliability of the micro-measurement accomplished and serve as subsidy for the calculation of the indicators of losses. The evaluation showed that the equipment with larger sensibility totaled, on average, a volume 13.56% higher than the more commonly used hydrometer. / A acelerada degradação dos recursos hídricos naturais, juntamente com a crescente demanda por água potável, faz com que programas de combate às perdas desse bem essencial se tornem cada vez mais indispensáveis aos gestores ambientais. Este trabalho está inserido nesse contexto, com o objetivo de avaliar a magnitude do erro de medição do parque de hidrômetros instalados na cidade de Uberlândia-MG, quando sujeitos às variações de demanda. Nesse sentido, buscou-se comparar o equipamento comumente utilizado com sistemas mais sensíveis à medição de baixas vazões, para verificar a confiabilidade da micromedição realizada e servir como subsídio para o cálculo dos indicadores de perdas. A avaliação mostrou que o aparelho com maior sensibilidade totalizou, em média, um volume 13,56% superior ao do hidrômetro normalmente utilizado. / Mestre em Engenharia Civil
13

Ultrasonic Flow Measurement for Pipe Installations with Non-Ideal Conditions

Stoker, Devin M. 01 December 2011 (has links)
In the arid west, water is among the most valuable of resources. Typically, in order to successfully and accurately measure a flow rate using most types of flow meters, it is recommended that a straight section of pipe be installed immediately upstream from the flow meter to avoid distorted flow patterns and extreme turbulence at the metering location. In many field piping situations, however, such flow conditions are impossible to achieve. The performance of ultrasonic flow meters in non-ideal piping scenarios was studied using laboratory experiments and numerical Computational Fluid Dynamics models. A Fuji PortaflowX clamp-on transit-time ultrasonic flow meter was calibrated in the laboratory and performed well within the manufacturer’s stated level of accuracy of ±1% for straight pipe. The ultrasonic flow meter was also used downstream of a single 12-inch long-radius elbow and the error in flow measurement resulting from the flow disturbance was measured. These tests were performed at four locations downstream of the elbow, at three orientations on the circumference of the pipe, and for three flow rates with Reynolds numbers ranging from 250,000 to 750,000. Using the same physical conditions, numerical models were built that utilized the realizable k-ε eddy viscosity model for turbulent flows. The resulting downstream velocity profiles from the numerical models were used to integrate the velocity of the flow across the ultrasonic signal path. The resulting velocity profiles were compared to similar profiles for fully developed flow to determine the error in flow measurement. The ultrasonic flow meter measurement errors downstream of the elbow were always negative, and were found to be as great as -16%. In general, the ultrasonic flow meter performed less accurately closer to the elbow due to the turbulent fluctuations and flow separation created by the elbow. A correction curve was applied to the results of this study, which provided a method to correct the ultrasonic flow measurement. By applying the correction equation to the laboratory ultrasonic flow meter measurements downstream of the elbow, the measurement error was reduced by nearly 90%. Computational Fluid Dynamics appears to be a viable tool for studying flow disturbances and making appropriate corrections for ultrasonic flow measurement in pipes.
14

Zdravotně technické instalace ve studentských kolejích / Sanitation installation in student dormitories

Kucharik, Miroslav January 2015 (has links)
Diploma thesis describes the design of plumbing systems in student dormitories. The theoretical part discusses the types of waste water, focusing on gray water and its subsequent use. The experimental part is focused on measurement drinking water consumption and drinking water discharge in existing buildings student dormitories and apartment building. The work also contains other variants of possible installation solutions. The project is part of the selected solutions developed a variant form of project documentation for construction.
15

The quality of water sample from Maungani community domestic water pots, Limpopo Province, South Africa

Okosi, Emmanuel Okori 05 1900 (has links)
MPH / Department of Public Health / See the attached abstract below

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