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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

A fundamental design study of electrochemical processes for the control of pathogenic bacteria

Cossali, Giovanna January 2015 (has links)
Water systems in buildings have been reported to contribute to pseudomonal infection transmission and have been associated with Legionnaires’ disease (LD) outbreaks, for they provide the perfect conditions for bacteria proliferation and biofilms formation. An overview of the problem has highlighted that the economic burden, the healthcare and mortality costs of both LD and pseudomonal infections are significant. Although critical to the safe delivery of water, pathogen control continues to remain a challenge as current hot water treatments are not always effective, are often energy intensive and require expensive maintenance. This thesis was set out to evaluate the potential use of electrochemical disinfection (ED) in controlling pathogens in hot water systems of buildings. In this project, we performed a fundamental systematic study on the effect of geometrical and operational parameters in a flask, to gather an understanding of the effect of each parameter on the rate of bacteria elimination, crucial for the design and optimization of electrolytic cells. ED prototypes were then installed in in the hot water systems of two different buildings operating at 60°C, the temperature recommended for Legionella control (HSE, 2013), and their efficacy was monitored long term. In one of the buildings, 2 to 4– log reductions in total bacteria counts was observed, while Pseudomonas species counts were reduced by 3 log. The apparent failure in the other building was due to the inadequate operation of the water system. In order to achieve the 2019 zero carbon targets for new non-domestic buildings set by the UK government, the energy demand associated with heating water needs to be addressed, but maintaining systems at such high temperatures renders difficult the use of greener technologies that could further reduce the CO2 impact of heating water. Given that ED generates disinfectants and that the Health and Safety Executive advises that if hot water is treated with biocides, water temperatures can be reduced, the efficacy of the prototype device was evaluated under laboratory conditions at temperatures between 30 and 45˚C. The prototype was found to be effective both on laboratory-grown biofilm and on planktonic Legionella pneumophila serogroup 1, with 5-log reduction on bacteria counts.
12

Resilience of urban water systems: an 'infrastructure ecology' approach to sustainable and resilient (SuRe) planning and design

Pandit, Arka 08 June 2015 (has links)
Increasing urbanization is a dominant global trend of the past few decades. For cities to become more sustainable, however, the infrastructure on which they rely must also become more efficient and resilient. Urban infrastructure systems are analogous to ecological systems because they are interconnected, complex and adaptive, are comprised of interconnected components, and exhibit characteristic scaling properties. Analyzing them together as a whole, as one would do for an ecological system, provides a better understanding about their dynamics and interactions, and enables system-level optimization. The adoption of this “infrastructure ecology” approach will result in urban development that costs less to build and maintain, is more sustainable (e.g. uses less materials and energy) and resilient, and enables a greater and more equitable creation of wealth and comfort. Resilience, or the capacity of a system to absorb shocks and perform under perturbations, can serve as an appropriate indicator of functional sustainability for dynamic adaptive systems like Urban Water Systems. This research developed an index of resilience (R-Index) to quantify the “full-spectrum” resilience of urban water systems. It developed five separate indices, namely (i) Index of Water Scarcity (IWS), (ii) Relative Dependency Index (RDI), (iii) Water Quality Index (WQI), (iv) Index of Network Resilience (INR), and (v) Relative Criticality Index (RCI), to address the criticalities inherent to urban water systems and then combines them to develop the R-Index through a multi-criteria decision analysis method. The research further developed a theoretical construct to quantify the temporal aspect of resilience, i.e. how quickly the system can return back to its original performance level. While there is a growing impetus of incorporating sustainability in decision making, frequently it comes at the cost of resilience. This is attributable to the fact that the decision-makers often lack a life-cycle perspective and a proven, consistent and robust approach to understand the tradeoff between increased resilience and its impact on sustainability. This research developed an approach to identify the sustainable and resilient (SuRe) zone of urban infrastructure planning and design where both sustainability and resilience can be pursued together.
13

The Solar Energy Tracker

Maples, David William January 2008 (has links)
Reference is increasingly being made towards the need for the world to find new and renewable forms of energy, especially for electric power generation, but also for space heating and the heating of water. Solar energy is one of the cheapest forms of renewable energy available and is so far one of the most underutilised resources. One contribution makes reference to the way forward as being ‘using concentrating solar power which uses parabolic mirrors to focus the solar heat (energy) and generate steam to drive electric generators’ as is currently happening in the utility power marketplace in the USA. This thesis deals with the issues surrounding the original development of a two axis solar energy tracking system (SET) in 1997. The subsequent redesign, development and upgrade, undertaken from 2002 to 2006, with its performance and efficiency being measured in 2006 and 2007 using a specially configured measurement and recording system. A Solar Energy Tracker (SET) is designed to track the sun moving in two axes, reflecting the solar radiation received on its mirrors to a target mounted at the end of a boom, at the focal point of the mirrors. In late 2005 and early 2006, a solar thermal hot water manufacturer and installer heard about the developments and requested some form of involvement, especially if Christchurch Polytechnic Institute of Technology (CPIT) provided research input and assisted in the further development and testing of solar thermal hot water systems. This sponsor offered two projects in 2006 and again in 2007. Other solar thermal hot water suppliers also requested involvement in the research and development being performed at CPIT, which led in August 2006, December 2006, June 2007 and December 2007, to a number of other solar thermal hot water and air wall systems being installed. Progressively, the roof of C block at CPIT has become full of solar thermal hot water systems and solar air wall systems, both of the conventional type and those with newer technologies at the core of their development. This thesis outlines the stages in the redesign and development of the SET, and the various stages in its testing, development and refinement up to its present form. The thesis chapters are written based around the mechanical and electrical design, the auto-tracking and daylight controls, the PLC (programmable logic controller) controller, the mirror and substrate testing, the SCADA (Supervisory Control And Data Acquisition) system, the testing and comparison with other domestic solar thermal hot water systems and finally the testing of the SET itself. It also details the future developments and outlines possible uses for the SET in its redefined form. With clean and polished mirrors the SET has proven itself capable of achieving a temperature rise across the target of 15 °C at a flow rate of 4 l/m. On some occasions this temperature rise can be in excess of 20 °C, but testing thus far, has shown this cannot be sustained for any worthwhile period of time (15-30 minutes). This translates to an efficiency of 5-10 % when related to an energy produced per twenty four hour time period. However, if the efficiency is calculated for the actual period of generation, ‘generation efficiency,’ then this figure rises to 24 %. An overview is given of associated solar thermal hot water and solar air wall system research and development (that is ongoing at CPIT) as well as the performance and efficiency graphs for the solar thermal hot water systems on test. No manufacturer’s, industry or brand trade names are mentioned, as this research is still confidential and commercially sensitive. However, the technology involved and characterised by each solar thermal system is recorded in a generic sense. The SET was originally developed with the purpose of heating hot water and today this is still the intent. The possible applications for this hot water are many and varied from electricity generation, space heating and further into developing or new industrial processes. The performances of the other domestic solar thermal hot water systems currently under test, are compared with the figures from the SET, with the maximum efficiency, presently available, being from an evacuated tube heat pipe system at up to 65 %, whereas traditional finned flat plate technologies have efficiencies after twelve months of up to 48 %.
14

Water Management Modelling in the Simulation of Water Systems in Coastal Communities

Sara, Barghi 29 July 2013 (has links)
It is no longer a question of scientific debate that research declares our climate is changing. One of the most important and visible impacts of this phenomenon is sea level rise which has impacts on coastal cities and island communities. Sea level rise also magnifies storm surges which can have severely damaging impacts on different human made infrastructure facilities near the shorelines in coastal zones. In this research we are concerned about the proximity of water systems as one of the most vulnerable infrastructures in the coastal zones because of the impact of stormwater combining with sewage water. In Canada, the government has plans to address these issues, but to date, there needs to be further attention to stormwater management in coastal zones across the country. This research discusses the impacts of severe environmental events, e.g., hurricanes and storm surge, on the water systems of selected coastal communities in Canada. The purpose of this research is to model coastal zone water systems using the open source StormWater Management Modelling (SWMM) software in order to manage stormwater and system response to storms and storm surge on water treatment plants in these areas. Arichat on Isle Madame, Cape Breton, one of the most sensitive coastal zones in Canada, is the focal point case study for this research as part of the C-Change International Community-University Research Alliance (ICURA) 2009-2015 project.
15

Water Management Modelling in the Simulation of Water Systems in Coastal Communities

Sara, Barghi January 2013 (has links)
It is no longer a question of scientific debate that research declares our climate is changing. One of the most important and visible impacts of this phenomenon is sea level rise which has impacts on coastal cities and island communities. Sea level rise also magnifies storm surges which can have severely damaging impacts on different human made infrastructure facilities near the shorelines in coastal zones. In this research we are concerned about the proximity of water systems as one of the most vulnerable infrastructures in the coastal zones because of the impact of stormwater combining with sewage water. In Canada, the government has plans to address these issues, but to date, there needs to be further attention to stormwater management in coastal zones across the country. This research discusses the impacts of severe environmental events, e.g., hurricanes and storm surge, on the water systems of selected coastal communities in Canada. The purpose of this research is to model coastal zone water systems using the open source StormWater Management Modelling (SWMM) software in order to manage stormwater and system response to storms and storm surge on water treatment plants in these areas. Arichat on Isle Madame, Cape Breton, one of the most sensitive coastal zones in Canada, is the focal point case study for this research as part of the C-Change International Community-University Research Alliance (ICURA) 2009-2015 project.
16

Natural Water Infrastructure: Integrating Nature Water Systems into Existing Infrastructure

Lenarduzzi, Laura January 2021 (has links)
No description available.
17

The Greco-Roman Water Catchment Theater: Identification and Distribution

Lee, Allison Nicole 01 March 2015 (has links) (PDF)
Water has always been a necessity for human beings. How individuals and populations have reacted to, adapted, and manipulated water is apparent in the archaeological record. Ancient urban water systems often utilized a number of components, including aqueducts, siphons, underground tunneling, and cisterns. This thesis proposes that Greco-Roman theaters were utilized as components of ancient urban water systems in specific environments, and that this theater type may be identified in the archaeological and literary record as a water catchment theater. The goal of my thesis was to define, describe, identify, and plot the distribution of water catchment theaters in order to compare their distribution with the environments where they were found. Previous research on Greco-Roman theaters has not focused on theaters as components of ancient urban water systems. Because of this deficiency, it was necessary to define what water catchment theaters were, describe the architectural traits that were found in water catchment theaters, and finally, using this information, identify water catchment theaters and look at their distribution throughout the Greco-Roman world. To meet my objective I created a new typology of water theaters based on extensive research and on-site visits to 30 theaters in five countries, surveyed and classified the 927 theaters found in Frank Sear's Roman Theatres: An Architectural Study, and plotted the distribution of water catchment theaters in relation to space, time, and climate. My study gives new insight into the uses of Greco-Roman theaters but also introduces new methods to examine these ancient buildings with relation to their potential roles in urban water systems.
18

Implementing US EPA's Operator Certification Program for Small Drinking Water Systems in Virginia

Adam, Carrie Ann 12 September 2000 (has links)
Virginia Tech researchers conducted a study to assist the Virginia Department of Health (VDH) in determining the policies and procedures necessary for the implementation of the United States Environmental Protection Agency final guidelines for the certification and recertification of small water system operators of community (CWS) and nontransient noncommunity public (NTNC) water systems serving under 3,300 people. A 42-question survey was developed and mailed to 2011 public water systems that serve 3,300 people or less. Survey results revealed that small systems in Virginia encompassed a diverse group of waterworks and owners/operators. Significant differences were found when survey results were analyzed by the number of people served and system category. Systems serving less than 100 people tended to not have a licensed operator, not have a full time employee, not meter their customers, and not have an operations and maintenance budget. As the system size increased, the likelihood of each increased. This research was supported by a grant from the Virginia Department of Health. / Master of Science
19

Clinoptilolite-polypropylene composites for the remediation of water systems polluted with heavy metals and phenolic compounds

07 June 2012 (has links)
M.Sc. / In this study, natural and modified clinoptilolite (CLI) reinforced polypropylene (PP) composites possessing improved mechanical and adsorptive properties were prepared through melt-mixing. Determination of morphological, structural and thermal properties was achieved by means of different techniques (FTIR, TGA, DSC, electron microscopy and x-ray spectroscopy). Electron microscopy revealed that increasing filler loading beyond 20% leads to agglomeration of clinoptilolite particles reducing their dispersion within the matrix. Thermal studies showed that the reinforced composites had a lower thermal stability than the neat PP polymer, suggesting that the clinoptilolite interfered with polymer chain arrangement and bonding. It also showed that percentage crystallinity increased with increasing filler loading indicating that the filler particles acted as nucleating agents within the polymeric matrix during composite synthesis. Prior to the ion-exchange studies, water sorption behaviour of fabricated composites was evaluated because ion-exchange/adsorption studies were to be performed in aqueous media. It was therefore observed that the hydrophobic polymer, PP attained the property of water sorption mainly due to the porous structure of the composites created by mixing and extrusion and also by the addition of the hydrophilic filler material.
20

Water Quality Monitoring in the SADC region

Macatsha, Nosimo 14 November 2006 (has links)
Student Number : 0107471X - MSc research report - School of Civil and Environmental Engineering - Faculty of Engineering and the Built Environment / Water plays a global role in an enormous variety of ways. More importantely it also plays a fundamental role on a regional and local scales where it has a profound effect on the environment and socio economic development. It is a prerequisite for many of the mans activities and as such it must be managed and protected accordingly. In this water quality plays a fundamental role and water quality monitoring is a foundation stone of any serious efforts to manage water resources on any scale. The research conducted focused on water quality monitoring in the SADC region. It looked at the current practice and the gaps present with respect to the real needs and international best practice. SADC region is characterized by trans-boundary water systems where pollution of water resources is often not understood properly nor has been seriously studied. A regional Water Quality Monitoring Program is advocated to address these issues and is seen as one of the prerequisites for effective water resources management in the SADC region. Existing Water Quality Monitoring in individual countries of the SADC region has been studied on the basis of existing (limited) information and gaps with respect to international best practice have been identified. Recommendations have been made regarding the establishment of the SADC Water Quality Monitoring program. A set of principles on which this should be based have been formulated. It has been concluded that SADC countries do not have an appropriate water quality monitoring in place and that what does exist is not in line with the best practice recommendations. It is suggested that without an appropriate regional water quality monitoring program water quality could become one of the limiting factors of the future economic development in the region.

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