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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.
151

Distritos de medição e controle como ferramenta de gestão de perdas em redes de distribuição de água / District metered area as a tool for managing losses in water distribution networks

Souza Júnior, José do Carmo de, 1975- 26 August 2018 (has links)
Orientador: Paulo Vatavuk / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-26T05:26:13Z (GMT). No. of bitstreams: 1 SouzaJunior_JosedoCarmode_M.pdf: 6575151 bytes, checksum: ab067f578f53eb5139546f4f0f2c13e2 (MD5) Previous issue date: 2014 / Resumo: O volume global de perdas de água é significativo. Cada ano, mais de 32 bilhões de m3 de água tratada são perdidos por vazamentos em redes de distribuição. Tendo em vista a complexidade dos sistemas de abastecimento de água, a divisão em sistemas menores permite analisar individualmente cada componente do sistema e definir ações que proporcionem uma gestão mais adequada. O presente trabalho tem por objetivo apresentar as ferramentas para gestão de perdas de água através da utilização dos Distritos de Medição e Controle (DMC's), que são áreas menores e mais gerenciáveis e possibilitam um controle efetivo de pressões e vazões nas redes de distribuição, proporcionando a redução dos volumes de água perdidos. A metodologia de utilização dos DMC's é internacionalmente aceita como uma das melhores práticas para redução de perdas de água, entretanto, sua aplicação é relativamente recente no campo de redes de distribuição. As áreas de abrangência dos DMC's são definidas tomando-se por base parâmetros como número de ligações de água, requisitos de pressão mínima e máxima, nível atual de vazamentos, limites do sistema de abastecimento, como áreas de bombeamento e áreas de válvulas redutoras de pressão, ou limites definidos através de estudos que identificam locais estratégicos para implantação de medidores de vazão. Após a implantação dos DMC's é realizado o gerenciamento das perdas de água, através do monitoramento das pressões e vazões. Os efeitos positivos do gerenciamento das pressões são reais para diminuir as perdas de água através da redução de pressões. A medição de vazão em redes de distribuição é outro fator importante no controle de perdas de água, pois sua correta utilização tem influência direta nos índices de perdas, onde é possível identificar áreas com níveis elevados de vazamentos. O trabalho apresenta um estudo de caso da implantação de DMC's no município de Bragança Paulista, operado pela Companhia de Saneamento Básico do Estado de São Paulo ¿ SABESP, demonstrando as ferramentas utilizadas para o gerenciamento das pressões e vazões, e propõe uma metodologia para intensificar os trabalhos de redução de perdas em DMC's, através de um sistema de informações geográficas, indicadores de desempenho adotados pela International Water Association (IWA) e da elaboração do balanço hídrico com o software gratuito do Banco Mundial WB-EasyCalc. Os resultados demonstram que a ferramenta possibilita uma gestão efetiva, através de uma ação mais focada nos DMC's que apresentam os maiores índices de perdas de água. Palavras-chave: Distrito de Medição e Controle (DMC), Rede de Distribuição de Água, Perdas de Água / Abstract: The overall volume of water losses is considerable. Each year, more than 32 billion m3 of drinking water are lost through leakage in water distribution networks. Given the complexity of water supply systems, the division into smaller structures allows the analysis of individual components and define actions that provides better management. This study presents the tools for managing water losses using District Metered Areas (DMAs), which are smaller and more manageable areas and enable effective control of pressures and flows in water distribution networks, providing a reduction in the volume of water losses. The methodology of using DMAs is internationally accepted as one of the best practices for reducing water losses, however, it¿s application is relatively new in the field of water distribution networks. The areas covered by the DMAs are defined by taking into consideration parameters like number of connections, minimum and maximum pressure requirements, current leakage level, limits of the water supply system as pump areas, and pressure reducing valves areas, or boundaries defined by studies that identify strategic locations for deployment of flowmeters. After having established DMAs, management of water losses is performed supervising the pressures and flow rates. The pressure management result in positive effects reducing water losses through reduced pressures. The measurement of flow in water distribution networks is another important factor in water loss control, because it¿s proper use has a direct influence on loss rates, where can identify areas with high levels of leakage. This study presents a case study about implementation of DMAs in the city of Bragança Paulista, operated by the Water Sanitation & Company of the State of São Paulo - SABESP, showing the tools used to manage pressures and flow rates, and proposes a methodology to improve works about water losses reduction in DMAs, through a Geographic Information System, performance indicators used by the International Water Association (IWA) and the development with the free water balance software from the World Bank, WB EasyCalc. The results shows that the tool allows effective management of water losses through actions in DMAs wich have the highest water losses. Keywords: District Metered Area (DMA), Water Distribution Network (WDN), Water Loss / Mestrado / Recursos Hidricos, Energeticos e Ambientais / Mestre em Engenharia Civil
152

Contribuição ao estudo do planejamento de reabilitação de redes de distribuição de água / Contribution to the study of planning for rehabilitation of water distribution networks

Orellana, Alex 19 August 2018 (has links)
Orientador: José Gilberto Dalfré Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-19T11:46:23Z (GMT). No. of bitstreams: 1 Orellana_Alex_M.pdf: 2196008 bytes, checksum: c129f161955e6e3ababf74b55fe054a0 (MD5) Previous issue date: 2011 / Resumo: Diversos operadores de sistemas de distribuição de água estão confrontando-se com a importante tarefa de reabilitar as redes de abastecimento de água. O envelhecimento das tubulações leva a aumentos na frequência de vazamentos, nos custos de operação e manutenção, nos problemas de regularidade do fornecimento de água, na qualidade da água e no volume de água perdida, acarretando em decréscimo da eficiência do sistema. Contudo, a reabilitação dos sistemas de distribuição de água ainda é uma questão controversa para os gestores dos serviços de saneamento, pois se há consenso sobre os efeitos negativos gerados pela deterioração das redes de distribuição, não há a mesma certeza quanto à decisão de reabilitá-las. Diante deste cenário, desenvolveu-se uma metodologia para o planejamento de reabilitação de redes de distribuição de água em larga escala. Trata-se de uma metodologia de planejamento para a identificação e classificação das áreas objeto de reabilitação utilizando-se a análise de dados cadastrais, indicadores de desempenho e histórico de dados operacionais, factíveis a uma empresa de saneamento. Para o desenvolvimento da metodologia foi utilizado o caso real do planejamento de reabilitação de redes da Unidade de Negócio Norte da Sabesp. Como resultados, apresentam-se as áreas elegíveis para reabilitação no sistema de abastecimento em estudo / Abstract: Several operators of water distribution systems are confronted with the important task of rehabilitating their supply networks. The aging of the pipes increases in the frequency of leaks, operation and maintenance costs, the problems of regular water supply, water quality and volume of water lost, resulting in a decrease in efficiency. However, rehabilitation of water distribution systems is still a controversial issue for managers of sanitation services, because if there is consensus about the negative effects generated by the deterioration of distribution networks, there isn't the same certainty about the decision to rehabilitate them. In this scenario, was developed a methodology for planning the rehabilitation of water distribution networks on a large scale. It is a planning methodology for the identification and classification of the subject areas of rehabilitation using the analysis of registration data, performance indicators and historical operational data, feasible at a sanitation company. In order to develop the methodology, it was studied the real case of rehabilitation planning from Business Unit North of Sabesp. As a result, shows the areas eligible for rehabilitation in the supply system under study / Mestrado / Recursos Hidricos, Energeticos e Ambientais / Mestre em Engenharia Civil
153

SEGMENT-BASED RELIABILITY ASSESSMENT FOR WATER DISTRIBUTION NETWORKS

Hernandez Hernandez, Erika 01 January 2017 (has links)
In recent years, water utilities have placed a greater emphasis on the reliability and resilience of their water distribution networks. This focus has increased due to the continuing aging of such infrastructure and the potential threat of natural or man-made disruptions. As a result, water utilities continue to look for ways to evaluate the resiliency of their systems with a goal of identifying critical elements that need to be reinforced or replaced. The simulation of pipe breaks in water reliability studies is traditionally modeled as the loss of a single pipe element. This assumes that each pipe has an isolation valve on both ends of the pipe that can be readily located and operated under emergency conditions. This is seldom the case. The proposed methodology takes into account that multiple pipes may be impacted during a single failure as a result of the necessity to close multiple isolation valves in order to isolate the “segment” of pipes necessary to contain the leak. This document presents a simple graphical metric for use in evaluating the performance of a system in response to a pipe failure. The metrics are applied to three different water distribution systems in an attempt to illustrate the fact that different pipe segments may impact system performance in different ways. This information is critical for use by system managers in deciding which segments to prioritize for upgrades or replacement.
154

Stochastic analysis of water supply systems including system hydraulics

Kretzmann, Hayley Ann 27 August 2012 (has links)
M.Ing. / Stochastic analysis of water distribution systems allow the performance of systems to be evaluated under more realistic conditions that involve both deterministic and probabilistic factors. A software package called Mocasim II has been developed to perform stochastic analysis on water supply systems. This allows the relationship between the reliability of the supply system and the capacity of its service reservoir(s) to be quantified using Monte Carlo analysis. In a Monte Carlo analysis the factors which influence the reliability of the system such as water demand, fires, and pipe failures are simulated stochastically over a long period of time. A reliability-capacity relationship is quantified by analysing the failure behaviour of different service reservoir sizes. A previous version of Mocasim used a simple mass balance model for calculating the flows in simple, linear distribution networks. Mocasim II extends the functionality of its predecessor by enabling the probabilistic modelling of more complex water distribution models. This was achieved by integrating the stochastic modelling technique into the Epanet hydraulic analysis software package. Mocasim II was designed using an object-oriented model which has various advantages such as ease of programme testing, upgrading and maintaining as well as minimum repetitive code and a logical structure. Additional capabilities of Mocasim II include the determination of probability distributions for network properties such as flow rate, pressure and water quality at any node in the network. This will assist in estimating the levels of service of a water supply system. This project focussed on developing sections of Mocasim II to be integrated with existing software such as Mocasim I, the Epanet hydraulic engine, OOTEN, and a random number generator. The software was tested thoroughly. This involved testing each class separately as well as applying it to a test case which is a simple network consisting of a source, reservoir and demand node. The theoretical background of the stochastic model has been investigated and various aspects discussed. Various case studies in Windhoek-Namibia, Mabeskraal-South Africa and an Epanet design example demonstrate the capabilities of the software and benefits of a stochastic analysis. A workbook to be used in addition to the software's help facility has been developed.
155

Assessing biofilm development in drinking water distribution systems by Machine Learning methods

Ramos Martínez, Eva 02 May 2016 (has links)
[EN] One of the main challenges of drinking water utilities is to ensure high quality supply, in particular, in chemical and microbiological terms. However, biofilms invariably develop in all drinking water distribution systems (DWDSs), despite the presence of residual disinfectant. As a result, water utilities are not able to ensure total bacteriological control. Currently biofilms represent a real paradigm in water quality management for all DWDSs. Biofilms are complex communities of microorganisms bound by an extracellular polymer that provides them with structure, protection from toxics and helps retain food. Besides the health risk that biofilms involve, due to their role as a pathogen shelter, a number of additional problems associated with biofilm development in DWDSs can be identified. Among others, aesthetic deterioration of water, biocorrosion and disinfectant decay are universally recognized. A large amount of research has been conducted on this field since the earliest 80's. However, due to the complex environment and the community studied most of the studies have been developed under certain simplifications. We resort to this already done work and acquired knowledge on biofilm growth in DWDSs to change the common approaches of these studies. Our proposal is based on arduous preprocessing and posterior analysis by Machine Learning approaches. A multi-disciplinary procedure is undertaken, helping as a practical approach to develop a decision-making tool to help DWDS management to maintain, as much as possible, biofilm at the lowest level, and mitigating its negative effects on the service. A methodology to detect the more susceptible areas to biofilm development in DWDSs is proposed. Knowing the location of these hot-spots of the network, mitigation actions could be focused more specifically, thus saving resources and money. Also, prevention programs could be developed, acting before the consequences of biofilm are noticed by the consumers. In this way, the economic cost would be reduced and the service quality would improve, eventually increasing consumers' satisfaction. / [ES] Uno de los principales objetivos de las empresas encargadas de la gestión de los sistemas de distribución de agua potable (DWDSs, del inglés Drinking Water Distribution Systems) es asegurar una alta calidad del agua en su abastecimiento, tanto química como microbiológica. Sin embargo, la existencia de biofilms en todos ellos, a pesar de la presencia de desinfectante residual, hace que no se pueda asegurar un control bacteriológico total, por lo que, hoy en día, los biofilms representan un paradigma en la gestión de la calidad del agua en los DWDSs. Los biofilms son comunidades complejas de microorganismos recubiertas de un polímero extracelular que les da estructura y les ayuda a retener el alimento y a protegerse de agentes tóxicos. Además del riesgo sanitario que suponen por su papel como refugio de patógenos, existen muchos otros problemas asociados al desarrollo de biofilms en los DWDSs, como deterioro estético del agua, biocorrosión y consumo de desinfectante, entre otros. Una gran cantidad de investigaciones se han realizado en este campo desde los primeros años 80. Sin embargo, debido a la complejidad del entorno y la comunidad estudiada la mayoría de estos estudios se han llevado a cabo bajo ciertas simplificaciones. En nuestro caso, recurrimos a estos trabajos ya realizados y al conocimiento adquirido sobre el desarrollo del biofilm en los DWDSs para cambiar el enfoque en el que normalmente se enmarcan estos estudios. Nuestra propuesta se basa en un intenso pre-proceso y posterior análisis con técnicas de aprendizaje automático. Se implementa un proceso multidisciplinar que ayuda a la realización de un enfoque práctico para el desarrollo de una herramienta de ayuda a la toma de decisiones que ayude a la gestión de los DWDSs, manteniendo, en lo posible, el biofilm en los niveles más bajos, y mitigando sus efectos negativos sobre el servicio de agua. Se propone una metodología para detectar las áreas más susceptibles al desarrollo del biofilm en los DWDSs. Conocer la ubicación de estos puntos calientes de biofilm en la red permitiría llevar a cabo acciones de mitigación de manera localizada, ahorrando recursos y dinero, y asimismo, podrían desarrollarse programas de prevención, actuando antes de que las consecuencias derivadas del desarrollo de biofilm sean percibidas por los consumidores. De esta manera, el coste económico se vería reducido y la calidad del servicio mejoraría, aumentando, finalmente, la satisfacción de los usuarios. / [CAT] Un dels principals reptes dels serveis d'aigua potable és garantir el subministrament d'alta qualitat, en particular, en termes químics i microbiològics. No obstant això, els biofilms desenvolupen invariablement en tots els sistemes de distribució d'aigua potable (DWDSs, de l'anglès, Drinking Water Distribution Systems), tot i la presència de desinfectant residual. Com a resultat, les empreses d'aigua no són capaces de garantir un control bacteriològic total. Actualment el biofilms representen un veritable paradigma en la gestió de la qualitat de l'aigua per a tots les DWDSs. Els biofilms són comunitats complexes de microorganismes vinculats per un polímer extracel·lular que els proporciona estructura, protecció contra els tòxics i ajuda a retenir els aliments. A més del risc de salut que impliquen els biofilms, com a causa del seu paper com a refugi de patògens, una sèrie de problemes addicionals associats amb el desenvolupament del biofilm en els DWDSs pot ser identificat. Entre altres, deteriorament estètic d'aigua, biocorrosión i decadència de desinfectant són universalment reconeguts. Una gran quantitat d'investigació s'ha realitzat en aquest camp des dels primers anys de la dècada del 80. No obstant això, a causa de la complexitat de l'entorn i la comunitat estudiada, la major part dels estudis s'han desenvolupat sota certes simplificacions. Recorrem a aquest treball ja realitzat i a aquest coneixement adquirit en el creixement de biofilms en els DWDSs per canviar el punt de vista clàssic del biofilm en estudis en els DWDSs. La nostra proposta es basa en l'ardu processament previ i posterior anàlisi mitjançant enfocaments d'aprenentatge automàtic. Es va dur a terme un procediment multidisciplinari, ajudant com un enfocament pràctic per desenvolupar una eina de presa de decisions per ajudar a la gestió dels DWDS a mantenir, en la mesura possible, els biofilm en els nivells més baixos, i la mitigació dels seus efectes negatius sobre el servei. Es proposa una metodologia per detectar les àrees més susceptibles al desenvolupament de biofilms en els DWDSs. En conèixer la ubicació d'aquests punts calents de la xarxa, les accions de mitigació podrien centrar-se més específicament, estalviant recursos i diners. A més, els programes de prevenció es podrien desenvolupar, actuant abans que les conseqüències del biofilm es noten pels consumidors. D'aquesta manera, el cost econòmic seria reduït i la qualitat del servei podria millorar, finalment augmentant la satisfacció dels consumidors. / Ramos Martínez, E. (2016). Assessing biofilm development in drinking water distribution systems by Machine Learning methods [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/63257 / TESIS
156

Manganese Accumulation and its Control in Chlorinated Drinking Water Distribution System / 塩素処理された水道配水システムにおけるマンガンの蓄積性とその制御

Zhou, Xinyi 24 November 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22841号 / 工博第4781号 / 新制||工||1748(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 伊藤 禎彦, 教授 米田 稔, 准教授 越後 信哉 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
157

Posouzení vybrané části vodovodní sítě / Assessment of a selected part of the water supply network

Mrázek, Jan January 2021 (has links)
The aim of this thesis is to research the field of water distribution system monitoring and modeling such system. In the next section the thesis describes a part of the water distribution system which is located in Pardubice district, specifically south of town Přelouč. With knowledge from the done research a hydraulic model will be done. This model made in EPANET interface will be calibrated and verified using data, which was acquired by the administrator of the system VAK Pardubice a.s. Afterwards new pipelines will be added to simulate the future situation accordingly to the area plans of the cencerned towns. Furthermore another aim is to simulate the requirements made towards the water distribution system in the future in case all the areas in area plan will be completely used. This will result into creation of forward looking hydraulic model which will show possible weaknesses of the water distribution system. In case of any shortcomings, according measures will be designed for future use.
158

Critical Node Analysis for Water Distribution System Using Flow Distribution

Hopkins, Michael 01 May 2012 (has links)
The expansive nature of water distribution system makes them susceptible to threats such as natural disasters and man-made destructions. Vulnerability assessment research efforts have increased since the passing of “Bioterrorism Preparedness and Response Act” in 2002 to harden WDS. This study aimed to develop a method that locates critical nodes without hydraulic analysis of every failure scenario, applicable for any size WDS, incorporates critical infrastructure, and capable of verifying method accuracy. The Flow Distribution method is the application of the gravity model, typically used to predict traffic flows in transportation engineering, to a distribution system. Flow distribution predicts the amount of demand and population that would be affected if any node in the system were disabled by solving for the distribution of each node’s outflow. Flow Distribution is applied to the hypothetical city, Anytown, USA using the computer simulation program WaterCAD to model two different disaster scenarios. Results were verified by analyzing sixteen failure scenarios (one for each node) to measure the actual demand and population effect, which was then compared to the nodes predicted by Flow Distribution. Flow Distribution predicted the critical nodes with 70% accuracy and can still be improved with future work.
159

Understanding the Impacts of Organic Matter on Microbial Biofilms in Engineered Drinking Water Systems

Li, Lei January 2020 (has links)
No description available.
160

Modelling of Pressurised Water Supply Networks that May Exhibit Transient Low Pressure - Open Channel Flow Conditions

Byakika, Stephen Nyende 03 1900 (has links)
D. Tech. (Department of Civil Engineering and Building, Faculty of Engineering and Technology), Vaal University of Technology / Growing demand for water due to increasing populations, industrialisation and water consuming lifestyles puts stress on existing water supply systems. To cater for the rising demand, water distribution networks are expanded beyond their design capacities and this creates transient “low-pressure-open-channel flow” (LPOCF) conditions. Current water supply models use “demand driven approach” (DDA) methodology which is not able to simulate transient LPOCF conditions, that poses an impediment to management/analysis of pressure-deficient networks. With a case study of the water supply network of Kampala City, LPOCF conditions were studied in this research. A “pressure/head driven approach” (PDA/HDA) was used in order to determine what demand is enabled by particular nodal pressures. Conversion of free surface to pressurised flow was analysed and modelled, with a view to clearly understanding occurrence of this phenomenon. The research demonstrated that if adequate pressures and flows are to be maintained, effectiveness of the water distribution network should be given as much attention as water production capacity. The research also indicated that when network pressures are low, the head-driven approach to water distribution modelling gives more accurate results than the traditional demand-driven methodology. Coexistence of free-surface and pressurised flow in networks prone to LPOCF conditions was confirmed and modelled. Results obtained highlighted the advantages of developing fully dynamic and transient models in the solution of transient LPOCF conditions in water distribution networks. Models developed allow application of PDA/HDA and DDA methodologies in systems that may exhibit LPOCF conditions thus enabling identification, understanding and analysis of the status of all sections of the network. These culminated in the development of a DSS to guide operational decisions that can be made to optimise network performance.

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