Search results for " water supply"

Control and prevention measures for legionellosis in hospitals: A cross-sectional survey in Italy

2018

Abstract Risk assessment, environmental monitoring, and the disinfection of water systems are the key elements in preventing legionellosis risk. The Italian Study Group of Hospital Hygiene of the Italian Society of Hygiene, Preventive Medicine, and Public Health and the Italian Multidisciplinary Society for the Prevention of Health Care-Associated Infections carried out a national cross-sectional survey to investigate the measures taken to prevent and control legionellosis in Italian hospitals. A multiple-choice questionnaire was developed, comprising 71 questions regarding hospital location, general characteristics, clinical and environmental surveillance, and control and preventive measur…

Experimental and modeling analysis of an apparent losses reduction device

2009

Drinking water source and cigarette smoking in transitional cell carcinoma of the bladder.

2006

OBJECTIVE: Water source and cigarette smoking are related to clinical characteristics and pathology of superficial transitional cell carcinoma of the bladder. METHODS: Tumor number, dimension, G-grade, T-stage, recurrences, cigarette smoking and water supply were recorded in patients harboring Ta-T1 G1-3 transitional cell carcinoma of the bladder. RESULTS: Of 577 patients, 61% had multiple and 36% recurrent tumors. Two hundred and forty-one patients (42%) were current smokers and 188 (33%) were former smokers. Bottled water was the only drinkable source for 249 (45%) patients, municipal water supply for 177 (32%), artesian wells for 38 (7%), spring water for 7 (1%) and mixed source for 89 (…

TOWERS, URNS AND CASTLETS. HISTORICAL EVIDENCE OF ANCIENT SYSTEMS OF WATER SUPPLY AND CONVEYANCE IN PALERMO

2016

Le vestigia del sistema distributivo idrico in uso a Palermo fino agli inizi del ventesimo secolo, sono ancora oggi visibili in alcune vie cittadine. Sono i castella dividicula, ovvero bacini di raccolta e distribuzione idrica. I castella dividicula comprendevano un sistema di urne, torri e castelletti posti ad un livello piezometrico equivalente alla quota della sorgente, sfruttando il principio dei vasi comunicanti. Il perpetuarsi del disuso e l’intensificarsi dell’attività edificatoria ha fatto si che molti di questi manufatti scomparissero inglobati all’interno di fabbricati, cortili, pozzi luce, o abbandonati come ruderi all’angolo di una piazza o lungo una via. Considerate per secoli …

The Economic Impact of Restricted Water Supply: a Computable General Equilibrium Analysis

2007

Water problems are typically studied at the level of the river catchment. About 70% of all water is used for agriculture, and agricultural products are traded internationally. A full understanding of water use is impossible without understanding the international market for food and related products, such as textiles. The water embedded in commodities is called virtual water. Based on a general equilibrium model, we offer a method for investigating the role of water resources and water scarcity in the context of international trade. We run five alternative scenarios, analyzing the effects of water scarcity due to reduced availability of groundwater. This can be a consequence of physical con…

A New Device for Pressure Control and Energy Recovery in Water Distribution Networks

2017

The potential energy of the water in Water Distribution Networks (WDNs) usually exceeds the amount needed for delivery and consumption and, at the present time, it is mainly dissipated through Pressure Reducing Valves (PRVs) or Open Water Tanks. The present study suggests the use of a new energy-producing device, a Cross-flow turbine with positive outlet pressure named PRS (Power Recovery System), which can provide the same service as PRVs and water tanks, with additional significant hydropower production. After a short presentation of the PRS, the management rules of the proposed device are laid out, according to two possible modes. In the ‘passive’ mode, the piezometric level downstream o…

Optimization of Osmotic Desalination Plants for Water Supply Networks

2016

Water scarcity and the poor quality of water resources are leading to a wider diffusion of desalination plants using the Reverse Osmosis (RO) process. Unfortunately, the cost of a cubic meter of fresh water produced by an RO plants is still high and many efforts are in progress to increase the efficiency of the membranes used in osmotic plants and to limit the energy required by the process. A further reduction of the energy cost could be obtained by an optimal operation of the desalination plant so reducing the hourly energy cost, or by coupling the RO plant with an energy production plant based on direct osmosis (Pressure Retarded Osmosis PRO). The economic viability of the desalination p…

Cross-Flow Turbine Design For Energy Production And Discharge Regulation

2015

Cross-flow turbines are very efficient and cheap turbines that allow a very good cost/benefit ratio for energy production located at the end of conduits carrying water from a water source to a tank. In this paper a new design procedure for a cross-flow turbine working with a variable flow rate is proposed. The regulation of the head immediately upstream the turbine is faced by adopting a shaped semicircular segment moving around the impeller. The maximum efficiency of the turbine is attained by setting the velocity of the particles entering the impeller at about twice the velocity of the rotating system at the impeller inlet. If energy losses along the pipe are negligible, the semicircular …

Evaluating Infrastructure Alternatives for Regional Water Supply Systems by Model-assisted Cost-benefit Analysis – A Case Study from Apulia, Italy

2014

The main challenge associated to regional water supply systems planning lies in understanding the best infrastructure alternatives to improve service given a certain configuration of the resources system. While cost-effectiveness assessments are still widespread in this type of analyses, they do not account for the fact that, especially in mature systems, service improvements tend to follow the law of marginal diminishing returns, so that a cost – benefit assessment should be preferable. Both costs and benefits can be organized into a cost-benefit analysis (CBA) framework. In a complex system, a model reproducing its topology and characteristics better describes the impacts of the alternati…

Sensitivity of Regional Water Supply Systems Models to the Level of Skeletonization – A Case Study from Apulia, Italy

2015

AbstractSimulation models supported by state-of-the-art software packages are nowadays available to explore operation rules of regional water supply systems or to select structural alternatives for improving long-term service performances.Given the, sometimes high, complexity of these systems, model calibration can become a lengthy procedure and many runs are necessary before obtaining convincing results. However, even after calibration, depending on system's complexity and the number of time steps investigated, a single run can take up to several minutes, even on state-of-the-art computers, so that simulation time can become a true bottleneck if such models are to be coupled with metaheuri…