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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.
321

The influence of a non-azeotropic refrigerant mixture on the performance of a hot water heat pump

Smit, Floris Jakobus 29 August 2012 (has links)
M.Ing. / The refrigerant R22, which is currently used in hot water heat pumps, delivers a maximum hot water temperature of 60 to 65 °C. This temperature is adequate for domestic use, but low if compared to temperatures that can be delivered by fossil fuels and direct electric resistance systems. This limits the potential applications of hot water heat pumps. In this study two analytical design methodologies were developed that can be used to predict the performances of water-to-water heat pumps. The first design methodology is for a pure R22 heat pump and the second for a non-azeotropic refrigerant mixture of R22 and R142b. These design methodologies were used as tools together with three methods of comparison to determine the influence of a non-azeotropic refrigerant mixture (R22 mixed with R142b) on the performance of a hot water heat pump. It was found in certain cases that, depending on the concentrations, not only are increased hot water temperatures possible but also an improved heating capacity, an improvement in the coefficient of performance and a reduction in pressure ratio of the compressor.
322

A Swamp in the Desert: Theory, Water Policy, and Malheur Lake Basin

Mandaville, Cristin R. 21 November 1995 (has links)
Two perspectives are debated in current United States water policy model development. One perspective calls for policy based on normative values, such as an environmental ethic. The second perspective calls for policy based on empirical, quantifiable values, for instance, economic benefits and costs. This theoretical debate arises from differing assumptions about what is problematic in contemporary water policy, and in turn gives rise to many water policy models. Developing such models ostensibly provides frameworks useful for developing real-world water policies. This paper proposes that these water policy models are not in fact useful frameworks for policy applications because the models do not accurately account for the actual circumstances confronting water policy makers. In order to illustrate this hypothesis, a comparison of two water policy models with a set of real-world policy circumstances is made here. The two models, each representing one of the dominant theoretical perspectives, are taken from David Lewis Feldman's Water resources manaiement: In search of an environmental ethic (1991) and Peter Rogers' America's water: Federal roles and responsibilities (1993). Feldman's model was selected to represent the normative perspective, and Rogers' model is selected to represent the empirical perspective. The real-world water policy circumstances selected for this study are those of Malheur Lake Basin, Oregon. This basin was selected because it provides the opportunity to consider a range of water policy issues and problems. This study shows that these two models do not offer adequate frameworks for applications. If water policy models are to provide useful frameworks for applications, model development must more closely consider actual cases.
323

Water conservation and water demand management pilot project: the case of Newcastle Municipality

Dube, Sandile Bonga January 2017 (has links)
A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, 2016 / The Newcastle Local Municipality (NLM) has been experiencing water supply interruptions since 2010 due to high demand. Between June 2011 to December 2011, water losses ranged from 49% to 62% (about 23 to 30 megalitres per day) in Madadeni and Osizweni townships (Newcastle East). The suburban areas (i.e. Newcastle West) also experienced water interruptions due to collapsing and/or aging infrastructure. About a thousand households in Madadeni were involved in this study to find the cause of the high water losses. Awareness campaigns, repairing household leaks, installation of intelligent meters and the increase of free basic water in indigent households from 6kℓ to 12kℓ per month reduced water losses from about 246 kℓ to 177kℓ per month. If similar Water Conservation (WC) and Water Demand Management (WDM) could be rolled out to the 35 000 households in the NLM and similar results to those in Madadeni are attained, conservative water saving of about 21Mℓ per day could be achieved. This would reduce the demand on the Ngagane Water Treatment Works (WTW) by 20%. / CK2018
324

Remote water quality diagnostic system

Gulzar, Iqra January 2019 (has links)
A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Masters of Science in Engineering, 2019 / Water is the basic necessity for all living organisms. About, five million people specifically children are dying each year due to dehydration or use of toxin infected water around the world. In South Africa approximately seventeen percent of the population do not have access to safe drinking water. Considering all of these challenges it is evident that monitoring the quality of water is important for providing safe and clean water. Several researchers have shown that the parameters related to the quality of drinking water can be monitored effectively in the field. To accurately determine the quality of water it needs to be tested for many parameters. Measuring all possible parameters can be a daunting task. It is very costly and time consuming at the same time. There is also research available in which researchers have proposed remote monitoring of water quality based on fewer parameters in a given water sample to conclude whether or not the given sample was safe for drinking. This has met with limited success. There is however very limited or no scientific evidence available to validate the effectiveness of the selected fewer parameters to determine the quality of drinking water. The research presented in this dissertation proposes a list of fewer parameters that are monitored to determine the quality of water. The effectiveness of those parameters in determining the quality of drinking water has been verified by conducting a detailed analysis on a number of water samples in a laboratory environment. The research has also proposed a system that is capable of monitoring those parameters remotely. This enables the water supplying authorities to determine the basic quality of water without testing it in the laboratory environment resulting in a decreased time and lower cost. / TL (2020)
325

Water Politics In The Middle East A Multicase Approach To Regional Water Shortage

Mulholland, Holly 01 January 2011 (has links)
Water shortage is a salient issue in the Middle East commonly overshadowed by more sensational topics such as the oil crisis and the Arab-Israeli Conflict. There is a debate among scholars as to whether water shortages in the Middle East will destabilize the region into armed conflict. Realists argue that non sustainable water sources will be the catalyst which will inevitably lead states to fight one another in a zero-sum game over limited water resources. Liberal Functionalists argue that there are precedents for multilateral cooperation and a technical approach may hold the key to providing solutions to the current water crisis. This research will examine three case studies from the Middle East region: the Jordan River Basin, the Tigris and Euphrates River Basin, and the Disi Aquifer on the border of Jordan and Saudi Arabia. Limited to a specific geographic region, these cases are indicative of water shortages that have or will become potential geostrategic centers for the water crisis.
326

Investigating the causes and impact of infrequent water supply on the wellbeing of communities : a case Greater Tzaneen Municipality, Limpopo Province

Makhubela, Ordnance Jabu January 2022 (has links)
Thesis (MPA.) -- University of Limpopo, 2022 / The provision of clean water and water scarcity are the most critical impediments to sustainable development in municipal water supply. Adequate water supply and sanitation services are essential for health, economic development, and environmental protection. Recognizing the importance of access to a safe and adequate water supply has become the core business of many South African municipalities. Among the major challenges facing local government regarding basic service provision in South Africa are acute problems of institutional capacity, maintenance of existing infrastructure, mismanagement of funds, high levels of corruption, political interference and a lack of public anticipation. There has been public outcry in South Africa about poor performance of municipalities in service delivery. Moreover, a good proportion of service delivery protests relate to municipalities‟ “failure to carry out” the supply of “basic” services like water.” It is against this” backdrop “that the” aim of this “study” was “to investigate the” causes of” infrequent “water” supply “on the” wellbeing “of” communities “in” the Greater Tzaneen Municipality, “Limpopo province. Although local municipalities in South Africa are regarded as the providers of essential services, such as water, to date most of the municipalities still lack the capacity to provide water services to community members across the country.” Greater Tzaneen “Municipality finds it challenging to provide water services to communities within its jurisdiction. To achieve this objective, the researcher utilised a combination of qualitative and quantitative research methodologies with a semi”- structured “questionnaire. The” study finds that the municipality is a water service provider and not as such has no authority in the provision of water to the villages. Moreover, it is found that the infrequent water supply has negative impact on the wellbeing of communities’ as water is a basic need and without it, it deprives the citizens of their dignity as enshrined in “Chapter two of the Bill of Rights of the” South African “Constitution.”
327

An Inventory of Public Water Supply Wells Owned and Operated by Orange County, Florida

Henry, Michael J. 01 July 1981 (has links) (PDF)
Orange County, Florida, through its Sewer and Water Department, own fifty active and ten inactive water treatment plants. These treatment plants have a total of ninety-four supply wells, sixty-four of which are actually in service. Most of these wells were obtained through purchase from private or investor owned utility companies. A file search was undertaken from records of the Orange County Sewer and Water Department, U.S. Geological Survey, former water system owners, and well drillers in order to compile all available information on these wells. Information was gathered on location, original drilling of the well, static water level and pumping tests, chemical and bacteriological quality of the water, and most recent pump, motor and auxiliary engine. This information was recorded on a date form for each well, with the well geographically categorized into five areas throughout the County. For each geographical area, mean, high and low values were determined for well and casing depth; static water level; well flow, specific pumping capacity and other flow type parameters; and various water quality parameters, such as total dissolved solids, chloride, sulfide, iron, alkalinity, and hardness concentrations. These were then compared to each other to see if any patterns could be established for wells in various areas of the County. Comparisons were also made to recorded piezometric surface levels of the Floridan Aquifer and to information in available literature on wells in the Orange County area. The comparisons indicated wells were slightly shallower in the wester part of the County than in the eastern part. Depth to static water level generally increased as you progressed from east to west, with the highest MSL elevations occurring in the southwest. Specific well capacity was greatest in the westerly area. Total dissolved solids content of the wells was much higher than that predicted by the literature, and hardness, iron and sulfide values were higher in the east than in the west.
328

Analysing Water Governance: A Tool for Sustainability

Franks, Tom R., Cleaver, Frances D. January 2009 (has links)
yes / Managing global water resources and providing water services to the world¿s people raises a continuing series of challenges, driven by increasing expectations, and a growing competition for water, which will be exacerbated by climate change. This paper explores how concepts of water governance and sustainability may help us to meet those challenges. Water governance is often equated with the role of government or management in the provision of water services. By contrast, we see governance as the system of actors, resources, mechanisms and processes, which mediate society¿s access to water. A broad conceptual framework is presented for the analysis of water governance, based on linkages between the resources available to society, the mechanisms that shape access to water and the outcomes of those mechanisms, both for people and the ecosystem. These linkages are mediated both by stakeholders and by management processes. It is argued that this conceptual framework offers a robust analytical tool for planning for sustainability as it is able to account for the complexities of water governance (of contexts, stakeholders, arrangements and uses). The paper concludes with observations about the ways in which the framework can be used to understand how different water governance arrangements produce variable outcomes in terms of sustainability.
329

A Parametric Simulation Model for Evaluating Cost Effectiveness of Remote Monitoring for Risk Reduction in Rural Water Supply Systems and Application to the Tazewell County, Virginia System

Wetzel, George L. 30 October 2003 (has links)
A simulation model analyzes cost effectiveness of remote facility monitoring for risk reduction in rural water supply systems by performing a break-even analysis that compares operating costs with manual and remote monitoring. Water system operating cost includes the value of water loss (i.e., realized risk) resulting from operating excursions which are inversely related to mechanical reliability. Reliability is controlled by facility monitoring that identifies excursions enabling operators to implement mitigating measures. Cost effectiveness refers to the cost relationship among operating alternatives that reveals changed economic conditions at different operating rates inherent in the inverse relationship between fixed and variable costs. Break-even analysis describes cost effectiveness by identifying the operating rate above which the more capital intensive alternative will result in lower operating cost. Evidence indicates that increased monitoring frequency associated with remote monitoring can reduce water system operating cost by improving reliability, but whether remote monitoring is cost effective depends upon system-specific factors. The lack of a documented tool for evaluating this type of cost effectiveness led to the project objective of developing a model that performs break-even analysis by simulating water system operating costs as functions of system size (delivery rate). When the spreadsheet-based static deterministic parametric simulation model is run for the Tazewell County, Virginia water system based upon 1998 data, break even is predicted at approximately fifty-five percent of annual capacity (116,338,000 gallons) with operating cost of $1,043,400. Maximum annual operating cost reduction from a $317,600 investment provides payback in nine years. / Master of Science
330

Consumptive Water Use: Refining State Water Supply Estimates with Discharge and Withdrawal Data

McCarthy, Mary Morgan 11 June 2019 (has links)
Water scarcity has quickly become one of the most pressing issues in the 21st century. Knowledge of the stress consumption places on water supply is therefore necessary for improved resource management. This research leverages monthly facility level withdrawal and discharge data from two different sources to provide important observations of consumptive water use across several spatial scales and water use sectors in Virginia between 2010-2016. Consumptive water is defined as water which is withdrawn and not returned to a water resource system. Consumption was estimated on statewide, watershed, county, and facility levels. The agriculture/irrigation, aquaculture, commercial, industrial, energy, and municipal sectors were considered for analysis. Facilities were matched between the two data sources by narrowing potential matches by distance and then by facility name using an approximate string distance mechanism. This analysis revealed that inconsistent discharge reporting affects estimates of consumption through time and any errors at finer spatial scales are ultimately masked at coarser levels. Statewide energy consumption in Virginia was found to be between 4-20% considering all available data and 0.4-4% across matched facilities. Non-energy consumption was an estimated 37-51% considering all available data and only 28-33% across matched facilities. Inconsistent reporting of discharge made it difficult to determine if consumption trends truly exist in Virginia, but monthly consumption appears to be persistent through time and slightly increasing in non-energy sectors. Industrial consumption in Virginia was also found to be higher than literature values. Results from this study are beneficial for water supply modeling and planning by providing more refined estimates of the actual stress withdrawals place on water supply. / This material is based upon work supported by the U.S. Geological Survey under Cooperative Agreement No. G17AC00322. The views and conclusions contained in this document are those of the author and should not be interpreted as representing the opinions or policies of the U.S. Geological Survey. Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey. / Master of Science / Water scarcity has quickly become one of the most pressing issues in the 21st century. Improved water resource management is critical for sustainable development, especially in historically water-rich states that have not had an urgency to improve water planning. This research provides key information about the impact consumption has on water supply in Virginia, using water use data from two different sources between 2010-2016. Consumptive water is defined as water which is withdrawn and not returned to a water resource system. This includes losses through evaporation, transpiration, conveyance, and incorporation into products and animals. Consumption was estimated on statewide, watershed, county, and facility levels. It was also estimated for the agriculture/irrigation, aquaculture, commercial, industrial, energy, and municipal sectors. Facilities were matched across the two data sources by narrowing potential matches by distance and then by facility name. This study revealed that statewide energy consumption in Virginia is between 4-20% considering all available data and 0.4-4% across matched facilities. Non-energy consumption is then between 37- 51% considering all available data and only 28-33% across matched facilities. Inconsistent reporting of return flow data made it difficult to determine if consumption trends truly exist in Virginia, but consumption appears to be persistent through time and slightly increasing in non-energy sectors. Results also suggest that industrial consumption in Virginia may be higher than published literature values. This study ultimately introduces a feasible method for water managers to estimate consumption using data from multiple sources. Results from this approach are beneficial for predicting future water demand and long-term resource planning by providing more knowledge of the actual stress withdrawals place on water supply.

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