• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 23
  • 22
  • 4
  • 1
  • 1
  • 1
  • Tagged with
  • 54
  • 54
  • 21
  • 19
  • 14
  • 9
  • 9
  • 7
  • 7
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 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.
41

A comparative assessment of communal water supply and self supply models for sustainable rural water supplies : a case study of Luapula, Zambia

Kumamaru, Koji January 2011 (has links)
Over the last couple of decades, a significant amount of research has been carried out on rural water supplies in developing countries, and have identified the fact that the communal water supply model is not sustainable everywhere, especially in sparsely populated rural areas; factors obstructing sustainability include lack of spare parts, management systems and private/public capacity. Despite their enormous contribution to the water sector, the extant studies stay within the subsidized communal water supply and capacity building, post construction support or management system. In other words, very few studies have been done into household (private) level water supply. The Self Supply model is an approach which provides support to households/communities to complement their efforts and accelerate sustainable access to safe water incrementally through improvement to traditional water sources (hand dug wells) by putting in their own investment. The Self Supply model may give significant benefits for sustainable safe water supplies, especially in sparsely populated rural areas, in comparison with the communal water supply though to date there has been little monitoring and systematic analysis of what impact these changes have made at the grassroots level. The standpoint of this study is pragmatic, and herein, mixing quantitative and qualitative methods was justified in order to design the research methodologies. The research was conducted in the Luapula Province of Zambia using a concurrent triangulation strategy to offset the weakness inherent within one method with the strengths of the other. The data was collected through inventory and sanitary surveys, water quality testing, household surveys, document analyses, focus group discussions and key informant interviews to determine the most appropriate water supply model for safe, accessible, sustainable, cost-effective and acceptable water supplies for households in sparsely populated rural areas of Zambia. The principal argument of this study is that reliance only on a communal water supply model limits the achievement of increased sustainable access to a safe water supply; hence a Self Supply model is needed which does not compete with the communal models but works alongside them in sparsely populated rural areas of developing countries for the purpose of increasing access and achieving sustainability. It was strongly defended by the overall findings that a Self Supply model could significantly reduce the faecal contamination risk in water quality and deliver a higher per capita water use and better convenience of access than the communal model; however its reliability with respect to the water source drying up needs to be monitored. Further, this does not mean that the communal model is not sustainable anywhere, rather that it is important to build blocks for a sustainable environment to access safe water in a symbiotic way between the communal and Self Supply models under the condition that the government and NGOs/external support agencies overcome the temptation to provide a water supply to rural dwellers as a giveaway social service.
42

Antropogeninės veiklos įtaka Širvintos upės vandens kokybei / The influence of anthropological activity to water quality of Sirvinta‘s river

Bukauskaitė, Laima 01 June 2011 (has links)
Magistro darbe tiriama antropogeninės veiklos įtaka Širvintos upės vandens kokybei. Darbo objektas – Širvintos upė (Vilkaviškio rajone) ir jos baseinas. Darbo tikslas – nustatyti ir įvertinti antropogeninės veiklos įtaką Širvintos upės vandens kokybei. Tyrimų metu, nustatyti taršos šaltinius, ir taršos pobūdį Širvintos upės baseine, - taip pat atlikti vandens kokybės stebėjimus. Darbo metodika – taršos šaltiniai ir jos pobūdis Širvintos upės baseine nustatyti analizuojant Vilkaviškio rajono savivaldybės administracijos darbuotojų pateiktą informaciją. Cheminė vandens pavyzdžių analizė atlikta keturis kartus per metus (kartą per sezoną) dešimtyje upės vagos vietų. Vandens kokybė vertinta lyginant gautus cheminės analizės duomenis su DLK vandens telkinyje – priimtuve ir su Paviršinių vandens telkinių, kuriuose gali gyventi ir veistis gėlavandenės žuvys apsaugos reikalavimais. Darbo rezultatai. Širvintos upės baseino pagrindinis taršos šaltinis – žemės ūkis. Baseine 53 % apima dirbama žemė, laikoma 1742 sąlyginių gyvulių, per metus susidaro apie 20287,2 m3 mėšlo, o visame susidariusiame mėšle vidutiniškai – apie 110,5 t azoto. Tyrimu nustatyta, kad Širvintos upė yra vidutiniškai užteršta. Vidutinė metinė skendinčių medžiagų koncentracija 2010 – aisiais 6,9 mg l-1, pagal šį rodiklį upės vanduo – labai geros kokybės. Vidutinis pH ir biocheminis deguonies sunaudojimas, tyrimų laikotarpiu, neviršijo nustatytų normatyvų. Didžiausia leistina amonio koncentracija – 0,78 mg l-1... [toliau žr. visą tekstą] / This Master‘s work researches the influence of anthropological activity to water quality of Sirvinta‘s river. The object of the work – Sirvinta‘s river (Vilkaviškis district) and it‘s reservoir. The aim of the work – ascertine and evaluate the influence of antropological activity to water quality of Sirvint‘s river; define pollution sources and it‘s attribution in the reservoir of Sirvinta‘s river; fullfil the observation of water quality. The method of the work – pollution sources and it‘s attribotion in the reservoir of Sirvinta‘s river are ascertined according to the proposed informatikon of municipality administration of Vilkaviškis district. The chemical water samples‘ analysis is accomplished four times a year (once a season) in ten channels‘ places of the river. The quality of the water is evaluated comparing attained facts of chemical anglysis with DLK in water mines and With surface of water mines, where the freshwater fish can live and pullulate. The results of the work. The main pollution source of Sirvinta‘s river is agriculture. 53 % involve farmland, 1742 – livestock. Muck pompose about 20287,2 m3 per year and about 110,5 t azote are composed from that muck. According to the research, Sirvinta‘s river is polluted on average. The annual material concentration was 6,9 mg l-1 on average in 2010. According to this index the water of the river is very good quality. Medium pH an biochemical oxygen consumption did not execeed the stints. The biggest permissible... [to full text]
43

Effect of winter storm on water quality and fish toxicity the Duwamish and Nisqually Rivers /

Ubilava, Mariam. January 2007 (has links) (PDF)
Thesis (M.E.S.)--The Evergreen State College, 2007. / Title from title screen viewed (1/17/2008). Includes bibliographical references (leaves 67-68).
44

Comparing nitrogen and phosphorous trends in two watersheds the case of the urban Cuyahoga and agricultural Maumee Rivers /

Senyah, Hubert A. January 2005 (has links)
Thesis (M.A.)--Miami University, Dept. of Geography, 2005. / Title from first page of PDF document. Document formatted into pages; contains [1], iv, 49, [6] p. : ill., maps. Includes bibliographical references (p. 44-49).
45

Kvalita pitné vody určené k hromadnému zásobování obyvatel / The Quality of Drinking Water in Public Distribution Systems

SOMPEKOVÁ, Zuzana January 2010 (has links)
This research project was aimed at monitoring the quality of drinking water that is supplied to the inhabitants of small villages. The quality of drinking water produced by small waterworks in South Bohemia, in municipalities Mazelov, Ortvínovice, Doubravka and Rábín, was studied. Sanitary analyses of drinking water samples carried out by the waterworks operators in 2004-2009 showed some variability in the concentrations of free chlorine, nitrates, pH, turbidity and the content of Escherichia coli in all the waterworks during the investigated period. The hypothesis assuming that the quality of drinking water produced by water treatment from small water sources is stable and that it does not vary in some key indicators, such as nitrates, the contents of Escherichia coli etc., throughout the year was not confirmed. The other hypothesis assuming that the number of small water sources used for public drinking water supplies decreases during the period was confirmed. The causes of these changes depend on many factors, such as the location and source of drinking water, the type of treatment plant, and, last but not least, the quality of service and economic potential of the waterworks operators play a negative role.
46

Aplicação e analise de um modelo de qualidade de agua para a determinação da concentração de cloro livre residual em um setor de abastecimento de agua / Use and analysis of water quality model to determine the free residual chlorine concentration in the water supply setor

Trimboli, Marcelo Jose 09 August 2018 (has links)
Orientador: Edevar Luvizotto Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-09T19:18:58Z (GMT). No. of bitstreams: 1 Trimboli_MarceloJose_M.pdf: 5392045 bytes, checksum: cc7d8b290241329ec9e101fc336f718c (MD5) Previous issue date: 2006 / Resumo: Neste trabalho são estudadas e avaliadas as etapas que visam a aplicação de modelagem matemática para obtenção de parâmetros de qualidade como a concentração de cloro livre residual em sistemas de abastecimento de água. Como estudo de caso e avaliação da proposição fui empregado o setor de abastecimento de Vila Liberdade na Cidade de Jundiaí-SP. Os resultados foram comparados com medições exaustivas de campo / Abstract: This work were studied and evaluated the stages that look for the use of the mathematics modeling to get parameters of quality like residual free chlorine concentration in network pipes . How case study and valuation of the proposition it was used the water supply sector of Vila Liberdade in the town of Jundiai - estate of São Paulo, BraziL The results were compared with exhaustive field measures / Mestrado / Recursos Hidricos / Mestre em Engenharia Civil
47

Analýza stížností odběratelů pitné vody / Drinking water customer complaints analysis

Trněná, Eva January 2019 (has links)
The diploma thesis deals with the analysis of complaints from drinking water customers, particullary about water quality. Within the theoretical part, it presents both the view of the customer of the drinking water and the view of the operator of the water supply system. It also presents possible ways to use drinking water customers complaints as indicators of water system service quality. Further, the thesis focuses on the satisfaction of customers and their trust in the operators of water supply systems. An analysis of complaints of drinking water users on the quality of water that has been received by the operator during the last five years has been performed as part of the case study in the practical part of the thesis. The cases are interpreted in context of the conditions at the given site of the water supply network.
48

Nekonvenční technologie obrábění vodním paprskem / The unconventional Technology of Cutting Water Jet

Šimíček, Václav January 2010 (has links)
This diploma thesis deals with the unconventional technology of cutting water jet. The aim of this thesis is analysis of technological possibilities of water jet, possible operating modes (techniques) and entering technological data and influence of technical parameters on quality and accuracy of cutting. The thesis contains several experiment at which was examined achieved quality and accuracy of cuts, and simultaneously there is solved technoeconomic evaluation of this technology.
49

LUSAKA, ZAMBIA: PROVISIONS OF WATER IN PERI-URBAN COMMUNITIES AND THE INTRODUCTION OF QUALITATIVE DYE TRACING FOR INVESTIGATION OF KARST GROUNDWATER SYSTEMS

Woodling, Kristen Marie 13 August 2014 (has links)
No description available.
50

Avaliação da qualidade de mistura de águas de salinidades diferentes com e sem dessalinização solar para a Região do Semi-Árido da Paraíba. / Quality evaluation of water mixtures of different salinities with and without solar desalination for the Paraíba Semi-Arid Region.

COSTA, Silvana Nunes da. 08 November 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-11-08T23:51:54Z No. of bitstreams: 1 SILVANA NUNES DA COSTA - DISSERTAÇÃO PPGECA 1992..pdf: 17415948 bytes, checksum: cbc9fe9ab0e76268ae3458f2074e4013 (MD5) / Made available in DSpace on 2018-11-08T23:51:54Z (GMT). No. of bitstreams: 1 SILVANA NUNES DA COSTA - DISSERTAÇÃO PPGECA 1992..pdf: 17415948 bytes, checksum: cbc9fe9ab0e76268ae3458f2074e4013 (MD5) Previous issue date: 1992-08-27 / Na região do Semi-Arido do Estado da Paraíba, a maioria dos mananciais superficiais e subterrâneos não somente tem pequena caudabilidade como também apresentam elevado teor de salinidade (cloreto - C1 - > 800 mg/1). Tais águas de alta salinidade e alta força iônica são impróprias para o consumo humano e/ou para outras finalidades. como tentativa para contornar esta situação, este trabalho mostra um estudo aprofundado de qualidade de águas de mistura em termos de grau de salinidade e de grau de saturação. A partir da utilização de águas sintéticas de alta e de baixa salinidade e de um desalinizador solar, em escala reduzida, tipo convencional, foram analisados os seguintes tipos de misturas: (I) tipo MD ou de água de alta salinidade com água dessalinizada e (II) tipo MB ou de água de alta salinidade com água de baixa salinidade. As águas sintéticas de alta salinidade foram preparadas com composição química similar àquelas da região do Semi-Árido Paraibano, e foi inserida uma espécie carbônica para simular águas naturais. Dois sistemas foram utilizados: a saber: (I) MaHCO3 + MaC1 + CaSO42H20 + H0O e (II) MaHCO3 + MaC1 + MgC12 + H0O. A variação do grau de salinidade foi feita a partir do teor de cloreto, ou seja: de 1.500 mg/1 a 3000 mg/1 para as águas de alta salinidade do sistema I, de 1000 mg/1 a 3500 mg/1 para as do sistema II e, finalmente, de 100 mg/1 a 200 mg/1 para as de baixa salinidade dos dois sistemas. Todas as simulações das águas e as determinações experimentais foram feitas no Laboratório de qualidade de Água da Companhia de Água e Esgotos da Paraíba - CAGEPA no alto Branco, Campina Grande, PB. Os resultados experimentais mostraram que ambos os processos de mistura são eficientes para a redução da salinidade das águas naturais e produzem um maior volume de água. A teoria do sistema carbonatado de Loewnthal & Marais (1976 e 1986) foi aplicada para verificação do grau de saturação das águas (potencial de precipitação/dissolução de carbonato de cálcio - CaCO3). Os resultados mostraram que as águas finais de ambas os tipos de misturas, apesar de leve tendência a subsaturação são praticamente estáveis. / In the Semi-Arid region of Paraiba State the majority of the superficial waters and groundwaters not only has a small yield hut also shows a high salinity concentration (chloride - CI- > 800 mg/1). Such waters of high salinity and high ionic strength are inadequate for human use and/or for other uses. In order to help to minimize this problem, this work shows a deep study on the quality of blended waters concerning its salinity and saturation degree. From the preparation of synthetic high salinity waters and low salinity waters and with the aid of a solar distiller, built in reduced scale and of the conventional type, it were analized the following types of blend, (i) blend MB or high salinity water with dessalinized water and (ii) blend MB or high salinity water with Lou salinity water. The synthetic high salinity waters were prepared with chemical composition similar to those of the Semi-Arid region of Paraiba and it was included a carbonic species in order to simulate a natural water. Two types of waters were used, i.e.: (I> MaHC03 + MaCl + CaSGU2HK0 and (II) MaHC03 i MaCl f MgC'ls: + CaCla + H3O. The degree of salinity was prepared from the chloride - Cl~ concentration; i.e.; from C1 - (mg/1) 1500 to 3000 for high 'salinity waters of the system I, from C1 - (mg/1) 1000 to 3500 for those of the system II and finally, from Cl~ (mg/1) 100 to 200 for low salinity waters. All simulations of the waters - and experimental determinations were made at the Laboratório of Water Quality of the Water and Wastewater Agency of Paraiba CAGEPA, in Alto Branco township, Campina Grande, PB. The experimental results indicate that both blending processes are efficient for minimizing the salinity of natural waters and produce a greater water volume. The theory of the carbonated system of Loewenthal & Marais (1976 and 1986) was applied to evaluate the saturation degree of the waters (potencial of precipitation/dissolution of calcium carbonate - CaCDs). The results showed that the final waters of both blending types although showing a slight subsaturation tendence, are practically stable.

Page generated in 0.1025 seconds