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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

Hydrological modeling to support simulation of an ozone exceedance episode over Texas

Stewart, Adam Gillis 12 1900 (has links)
No description available.
12

Handheld infrared CO2 gas detector

Coetzee, George January 2000 (has links)
A handheld InfraRed (IR) Carbon Dioxide (CO2) gas detector was developed and used to carry out a study of water and urine samples in South Africa. The details of the model and the results of the study are discussed here. The overseas markets are not geared for the current South African conditions. Use is made of components that can be obtained locally. Imported components are very expensive and should an imported model be damaged, it has to be returned overseas to be repaired. As an illustration of this technology it was decided to perform research in water technology and then develope a handheld Infrared CO2 gas detector based prototype which would: highlight the benefits of using handheld IR CO2 gas detectors; be built locally; be powered by a 12 Volt supply; be very easy to maintain; and be cost effective. Experimental results on the accuracy and stability of the instrument formed part of this study. The IR CO2 Gas detector that was developed was used throughout the project as a prototype and testing vehicle for numerous designs. It proved to be superior to the current imported commercial instruments in terms of size, cost effectiveness and user friendliness. A further advantage of the instrument is its robustness.
13

Investigating the toxicity of Dense Non-aqueous Phase Liquids (DNAPL) in contaminated groundwater

Mwamba, Olivier 24 June 2009 (has links)
M.Tech. Biomedical Technology / Previous studies have reported on the potential health risks associated with direct contact with chemicals (such as DNAPLs) via inhalation or drinking of contaminated groundwater. Dense Non-Aqueous Phase Liquids (DNAPLs) enter into groundwater through incorrect storage or disposal and pose risk to human health. Industrialization contributes considerably to contamination of ground water with waste disposal practices leading to the deposition of hazardous waste at geologically/hydro-geologically unsuitable locations. Many hazardous chemicals found their way into groundwater by this mean and might cause problems if ingested in drinking water. Most of these compounds undergo only limited degradation in the subsurface, and persist for long periods of time while slowly releasing soluble organic constituents that present hazardous health effects (both toxic and non-toxic) to humans.
14

Statistical evaluation of water quality measurements

Bujatzeck, Baldur January 1998 (has links)
No description available.
15

Quantitative and Qualitative Responses of Lake Eola to Urban Runoff

Walsh, Timothy B. 01 October 1981 (has links) (PDF)
For temperate lakes which receive a variable nutrient loading with seasonal variance in their hydrology, it is necessary to consider the dynamic response of the lake to these variable nutrient loadings. An approach to evaluate Lake Eola water quality responses to dynamic discharge of nutrients is presented. The major source of nutrients for this lake is stormwater runoff containing nitrogen and phosphorus. A mass balance of nutrient sources and sinks for the period of one year (April 1980 - March 1981) was performed. To accomplish this, a field determination for various parameters of the hydrologic budget was performed on a monthly basis. A monthly water quality analysis of the lake was measured. It was determined that Lake Eola was phosphorus limited and that 87% of the Total Phosphorus entering the lake via stormwater runoff was retained in the bottom sediments. Retention of various nutrients ranged from 77% to 93%. In order to evaluate the dynamic response of this lake, it was necessary to consider the retention of the nutrients as a function of time. The inductive methodology for this analysis and an example for Total Phosphorus is presented.
16

Development of a water sample concentrator for the concentration of bacteria in drinking water

Daugherty, James Michael January 1982 (has links)
A water sample concentrator utilizing a membrane adsorption/elutriation procedure for bacterial recovery was developed and field-tested. Influent sample volumes of 19.0 liters were processed by the concentrator within 10 minutes. Standard MPN and membrane filtration tests were conducted to determine the efficiency of the concentrator. In laboratory experiments, an average bacterial recovery of 48 percent was accomplished when E. Coli was the bacterium concentrated. An average recovery of 78 percent was achieved with Streptococcus faecalis. Various commercially available 142 mm diameter membrane filters were tested with the concentrator. Millipore membrane filters having a porosity of 0.45 m were found to be superior to Cox membrane filters with 0.45 and 5.0 m porosities and to zeta plus filters. The most promising technique for eluting bacteria from the membrane filter appeared to consist of mixing the filter and 125 mL of three percent bovine serum solution at pH 9.0 in an electric blender for 30 seconds and then allowing 15 minutes of contact. Miscellaneous experiments investigated the addition of multivalent cations to enhance adsorption of bacteria to the membrane filters, the use of vacuum induced flow through the concentrator and the possibility of monitoring bacterial levels through adenosine triphosphate analysis. In the field trials, the water sample concentrator detected coliform bacteria in drinking water in which no coliforms were detected in grab samples by the standard MPN method. / Master of Science
17

Apportionment of air particulate sources in Hong Kong: development of sampling and analytical methods for thedetermination of organic and inorganic compounds

Cheung, Ho-kwong., 張可光. January 1996 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy
18

An Analysis of Quality Improvement Education at US Colleges of Pharmacy.

Cooley, Janet, Stolpe, Samuel F, Montoya, Amber, Walsh, Angela, Hincapie, Ana L, Arya, Vibhuti, Nelson, Melissa L, Warholak, Terri 04 1900 (has links)
Objective. Analyze quality improvement (QI) education across US pharmacy programs. Methods. This was a two stage cross-sectional study that inspected each accredited school website for published QI curriculum or related content, and e-mailed a questionnaire to each school asking about QI curriculum or content. T-test and chi square were used for analysis with an alpha a priori set at .05. Results. Sixty responses (47% response rate) revealed the least-covered QI topics: quality dashboards /sentinel systems (30%); six-sigma or other QI methodologies (45%); safety and quality measures (57%); Medicare Star measures and payment incentives (58%); and how to implement changes to improve quality (60%). More private institutions covered Adverse Drug Events than public institutions and required a dedicated QI class; however, required QI projects were more often reported by public institutions. Conclusion. Despite the need for pharmacists to understand QI, it is not covered well in school curricula.
19

Quality Assessment for HEVC Encoded Videos: Study of Transmission and Encoding Errors

Ansari, Yousuf Hameed, Siddiqui, Sohaib Ahmed January 2016 (has links)
There is a demand for video quality measurements in modern video applications specifically in wireless and mobile communication. In real time video streaming it is experienced that the quality of video becomes low due to different factors such as encoder and transmission errors. HEVC/H.265 is considered as one of the promising codecs for compression of ultra-high definition videos. In this research, full reference based video quality assessment is performed. The raw format reference videos have been taken from Texas database to make test videos data set. The videos are encoded using HM9 reference software in HEVC format. Encoding errors has been set during the encoding process by adjusting the QP values. To introduce packet loss in the video, the real-time environment has been created. Videos are sent from one system to another system over UDP protocol in NETCAT software. Packet loss is induced with different packet loss ratios into the video using NETEM software. After the compilation of video data set, to assess the video quality two kind of analysis has been performed on them. Subjective analysis has been carried on different human subjects. Objective analysis has been achieved by applying five quality matrices PSNR, SSIM, UIQI, VFI and VSNR. The comparison is conducted on the objective measurement scores with the subjective and in the end results deduce from classical correlation methods.
20

Study of selected water quality parameters at Narellan Creek

Xu, Yan Fan, University of Western Sydney, College of Health and Science, School of Biomedical and Health Sciences January 2006 (has links)
A two-year study was conducted at the Narellan Creek Catchment between September 1998 and August 2000. To improve the quality of the water that flows in to the Nepean River, the Harrington Park retention basin was enlarged and rehabilitated from 7.0 ha to 12.0 ha area. This study measured several parameters of water quality to assess the efficiency of the Harrington Park retention basin for water quality improvement. Three sampling sites – the Camden Valley Way (CVW), Harrington Park retention basin (HPK) and Kirkham Lane (KLN) were selected for sample collection. Water flows from CVW to HPK then to KLN and finally to the Nepean River. Rainfall, water level, discharge rate and ambient temperature were recorded at the KLN site while the selected water quality parameters were determined at all the three sites. Low flow samples were manually collected at monthly intervals. An auto-sampler which collected water samples during rain events (for high flow data) was set up at the KLN site. Rising stage samplers which collected water at different water levels during a rain event, was set up at all the sites but data from this device was found to be of limited use due to the varying time lags between the filling of each bottle. Statistical analyses by various measures show that the Harrington Park retention basin played a significant role in improving the upstream and in-stream water quality. These study shows that constructed wetlands like the Harrington Park retention basin has the ability to significantly improve the water quality of a catchment. The water quality improvement is greater at lower water flow rates. / Doctor of Philosophy (PhD)

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