Browsing by Issue Date, starting with "2018-09-20"
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- Locating Unreported Leaks with Modelling Tools and Pressure Monitoring: a Case StudyPublication . Ribeiro, Luisa; Sousa, Joaquim; Muranho, João; Marques, Alfeu SáWater losses are a major concern for water companies, mostly due to their economical, technical, social and environmental negative impacts. Unreported leaks are a major cause of water losses in water distribution networks (WDNs) and they are difficult to locate, particularly in plastic pipes, large diameters and low pressure conditions. The location of these leaks is very time consuming and requires specialized human resources, using sophisticated and costly acoustic equipment. The use of modelling and optimization tools, supported by flow and pressure measurements, is showing to be a challenging alternative to the traditional procedure. This paper presents the application of the methodology proposed in Ribeiro L. S., 2012; Ribeiro L. S., 2015; Sousa, 2015 to a real WDN, highlighting the major difficulties faced when dealing with real world conditions, namely gathering and checking data, and building and calibrating the water distribution model. The results obtained in this case study show that this approach is very promising, encouraging future applications and developments
- Qualidade de vida após encerramento de estomaPublication . Santos, Pedro Miguel Dias dos; Vaz, Pedro Renato Sousa da Silva; Monteiro, Ana; Borges, SílviaDoentes com estomas de eliminação intestinal enfrentam inúmeros problemas tanto físicos como psicológicos. O encerramento do estoma apresenta-se como uma solução para esses problemas. Embora seja geralmente considerado um procedimento simples não previne eventuais complicações decorrentes tanto da patologia de base como da intervenção cirúrgica ou dos processos que lhe estão associados Esta dissertação surge com o propósito de, através da revisão bibliográfica e de um estudo retrospetivo com aplicação do score LARS aos doentes submetidos ao restabelecimento do trânsito intestinal após realização de estoma, analisar o real impacto do encerramento do estoma na qualidade de vida dos doentes nomeadamente no que diz respeito à continência fecal. Este estudo permitiu constatar uma baixa incidência de incontinência fecal bem como uma melhoria da qualidade de vida após o encerramento do estoma. A aplicação de questionários validados e o seu uso generalizado na prática clínica, com vista a um follow-up padronizado, permitirá a adoção de melhores estratégias visando maximizar a qualidade de vida do doente.
- Optimal District Metered Area Design by Simulated AnnealingPublication . Gomes, Ricardo; Sousa, J.; Marques, Alfeu Sá; Muranho, JoãoWater losses reduction in Water Distribution Systems (WDSs) is nowadays an issue of growing importance for water companies to ensure the economic sustainability of these public services. In this context, the implementation of District Metered Areas (DMAs) and/or pressure management are considered effective tools for leakage control, particularly in large networks and in systems with deteriorated infrastructures and with high pressure. Based in previous studies performed by the authors (Gomes et al., 2012; Gomes et al., 2015; Sousa et al., 2015), the methodology described in this paper follows the ‘water losses management international best practices’ and makes it possible to evaluate the Net Present Value (NPV) of DMAs project, as well as the benefits that can be achieved by pressure management in WDS, particularly in terms of water production reduction. Leakage assessment is performed using the analysis of the minimum night flow and the FAVAD concept, and it uses a pressure driven simulation model to predict the network hydraulic behaviour under different pressure conditions. The optimal location of DMAs entry points, pipes reinforcement/replacement and locations/settings of the Pressure Reduction Valves (PRVs) are identified by a Simulated Annealing algorithm. The potential of this methodology is illustrated through an hypothetical case study.
- Water Distribution Network Reliability: are Surrogate Measures Reliable?Publication . Muranho, João; Sousa, J.; Marques, Alfeu Sá; Gomes, RicardoWater distribution networks (WDNs) must be reliable infrastructures since they provide an essential service to society. Reliability assessment is a complex task and involves various aspects: mechanical, hydraulic, water quality, water safety, among others. This paper focus is on the hydraulic reliability. Hydraulic reliability is computationally hard to measure directly, therefore researchers came up with surrogate measures, like the resilience index, the modified resilience index, the flow entropy or the diameter-sensitive flow entropy, that are simple and fast to compute. But, are these surrogate measures reliable to be used in the design of WDNs? This paper proposes a new reliability index based on the surplus flow available on each node to mitigate the effects of a pipe failure. To illustrate the applicability of this new index, a WDN example is optimally designed (simulated annealing algorithm embedded in WaterNetGen) in order to maximize some reliability index subject to a given budget. Results show that the solutions based on the flow entropy or the proposed index are more reliable than the others, and, also, the maximization of the other reliability indexes gives only a residual contribution to the global reliability (or even no contribution at all).