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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.
1

The effects of using a cation exchange water softener on blood pressure

Kang, Ki Sung 29 August 1990 (has links)
Water in 70 percent of the cities in the United States is hard enough that softening is either required or recommended. It is estimated that approximately 30 percent of all homes in the United States use water softeners. Water softeners, the cation exchange types suited for residential use, exchange sodium for the calcium and magnesium in water. The increase in sodium levels in the softened water caused by cation exchange softening is a direct function of the hardness level of the untreated water. For people who use groundwater, which has a relatively high level of naturally occurring sodium, magnesium and calcium, the additional sodium from cation exchange water softeners may create health hazards for the general population and could adversely affect those who are sensitive to salt or on low sodium diets. To prevent potential health hazards for the general population, no consumption of softened water by cation exchange water softeners should be recommended. If soft water is needed for some practical reasons, a "Separate Water Line System" should be recommended for homeowners. / Graduation date: 1991
2

Identifying the prevalence of and pathways to diarrhoeal disease in rural KwaZulu-Natal and the implications for evaluating the impact of water supply schemes on community health.

Archer, Lynette Deborah. January 1999 (has links)
Since the establishment of a democratic South Africa in 1994, a number of rural water supply schemes have been implemented. A specific aim of these schemes is to improve the health of the population. The underlying assumption is that a supply of reticulated water will improve the quality of water used by the community, reduce the exposure of the community to contaminated water supplies, and reduce water related diseases, in particular diarrhoea. This research thesis focuses on two rural water supply schemes in KwaZulu-Natal: Mpolweni and Vulindlela, both being developed by Umgeni Water, the regional water utility. These communities depended variously on rivers, rain harvesting, and springs for their water supply. For sanitation, the majority of people used unimproved pit latrines. This research thesis is based on information gathered from the communities prior to the installation of the water supply schemes. It focuses on the linkage between water supply and health by examining diarrhoeal morbidity as a measurable disease outcome and by identifying possible pathways to the prevalence of diarrhoea. Questionnaire and observational surveys were undertaken of 181 households in Mpolweni and 100 households in Vulindlela. From these surveys, the prevalence of diarrhoea in Vulindlela households was found to be 40.4% and in Mpolweni to be 49%. Children under the age of five years old are the most vulnerable, with 20.1% of children in Mpolweni and 21 .3% of children in Vulindlela reported as having had diarrhoea in the recall period prior to the surveys. The Mpolweni study considered eighty exposure variables, finding an association between diarrhoeal disease and sixteen of these variables (p value < 0.05). The Vulindlela study considered fifty-five exposure variables, of which eight were considered significant (p value < 0.05). In regard to water and diarrhoea: • no association was found between the prevalence of diarrhoea and the source of water in either Mpolweni or Vulindlela. • using water to wash nappies was associated with diarrhoeal disease in Vulindlela. However, it is postulated that it is the faecal contamination in the nappy, rather than the water, that is problematic. No association between water use and diarrhoea was established in Mpolweni. • poor disinfection of stored water supplies was associated with diarrhoeal disease in both Mpolweni and Vulindlela. In addition, the use of plastic storage containers to store water at the household provided additional risk in Mpolweni. However, once the reticulated system is installed, the communities are likely to continue to store water due to a distrust of the reliability of water supply. The above surveys form the baseline for additional studies currently being undertaken by Umgeni Water that are intended to measure the effectiveness of the water supply schemes on community health. However, from this thesis, it is concluded that many of the risk factors associated with diarrhoeal disease in both Vulindlela and Mpolweni will not directly be addressed by the introduction of the water supply schemes. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2000.
3

Medical radionuclides and their impurities in wastewater

Hay, Tristan Ryan 24 May 2014 (has links)
NCRP report No.160 states that medical exposure increased to nearly half of the total radiation exposure of the U.S. population from all sources in 2006 (NCRP 2009). Part of this increase in exposure is due to the rise in nuclear medicine procedures. With this observed growth in medical radionuclide usage, there is an increase in the radionuclide being released into wastewater after the medical procedures. The question then arises: what is the behavior of medical radionuclides and their impurities in the wastewater process? It is important to note that, often, medical radionuclides are not exactly 100% radionuclide pure, but they meet a certain standard of purity. Of particular interest are the longer lived impurities associated with these medical radionuclides. The longer lived impurities have a higher chance of reaching the environment. The goal of this study is to identify the behavior of medical radionuclides and their impurities associated with some of the more common radiopharmaceuticals, including Tc-99m and I-131, and locate and quantify levels of these impurities in municipal wastewater and develop a model that can be used to estimate potential dose and risk to the public. / Graduation date: 2012 / Access restricted to the OSU Community at author's request from May 24, 2012 - May 24, 2014
4

Experiences of Laotian teachers of the Human Values Water, Sanitation and Hygiene Education training programme

Padayachee, Silverani 01 1900 (has links)
Access to safe water and improved sanitation remains threatened by the ever increasing demand in urbanised cities of the world. Adequate management of this problem could not be achieved through technical and regulatory methods alone. A human values-based education approach, namely the Human Values Water, Sanitation and Hygiene Education (HVWSHE) programme, was considered a suitable intervention strategy to bring about the desired changes in attitude and behaviour by the water users. This research involves an empirical case study approach that explores the experiences of Laotian teachers as adult learners of the HVWSHE intervention as well as a literature study on adult education, adult learning facilitation, human values-based education and teacher beliefs. Focus group meetings, lesson observations, participant observation, field notes and a researcher journal was used to collect data. This study revealed that the HVWSHE training programme had a positive effect on the adult learners’ attitude and behaviour towards a better water-use and sanitation-friendly ethic. / Educational Studies / M. Ed. (Adult Education)
5

Experiences of Laotian teachers of the Human Values Water, Sanitation and Hygiene Education training programme

Padayachee, Silverani 01 1900 (has links)
Access to safe water and improved sanitation remains threatened by the ever increasing demand in urbanised cities of the world. Adequate management of this problem could not be achieved through technical and regulatory methods alone. A human values-based education approach, namely the Human Values Water, Sanitation and Hygiene Education (HVWSHE) programme, was considered a suitable intervention strategy to bring about the desired changes in attitude and behaviour by the water users. This research involves an empirical case study approach that explores the experiences of Laotian teachers as adult learners of the HVWSHE intervention as well as a literature study on adult education, adult learning facilitation, human values-based education and teacher beliefs. Focus group meetings, lesson observations, participant observation, field notes and a researcher journal was used to collect data. This study revealed that the HVWSHE training programme had a positive effect on the adult learners’ attitude and behaviour towards a better water-use and sanitation-friendly ethic. / Educational Studies / M. Ed. (Adult Education)

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