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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.
21

Hydraulic Characteristics Of Tyrolean Weirs Having Steel Racks And Circular-perforated Entry

Sahiner, Halit 01 March 2012 (has links) (PDF)
Tyrolean type water-intake structures are commonly used on mountain rivers to supply water to hydropower stations. The amount of water to be diverted from the main channel is the major concern in these kind of structures and should not be less than the design discharge. In this study a physical model of a Tyrolean type water-intake structure was built at the laboratory and the diverted flow from the main channel through the intake structure having steel racks and perforated plates of different types were measured. The experiments were conducted in two stages. In the first stage the tests were carried out with only steel racks having three different bar openings and slopes, and in the second stage, perforated screens of three different circular openings and screen slopes were used. Applying dimensional analysis to the related parameters of the system the dimensionless terms were defined for the water capture efficiency and discharge coefficient of the system, and their variations with the relevant parameters were plotted. Using these diagrams one can determine the amount of water to be diverted by a Tyrolean weir of known geometry and main channel discharge.
22

Modellierung historischer Abflussverhältnisse für die Hochwasserprognose

Kirsch, Franziska, Pohl, Reinhard 11 February 2015 (has links) (PDF)
Um historische Durchflussangaben an Flüssen, die in die Hochwasserstatistik eingehen, überprüfen und bewerten zu können, werden 1-D- und 2-D-Wasserspiegellagenberechnungen unter Verwendung historischer morphologischer Daten durchgeführt. Die Methodik sowie ihre Möglichkeiten und Grenzen werden am Beispiel der Elbe im Stadtgebiet von Dresden erläutert.Es wird deutlich, dass die notwendigen Korrekturen auch Auswirkungen auf die Hochwasserstatistik und damit auf die Schutzgrade haben.
23

Water Metering in Rural, Piped, Community-Managed Water Systems in the Developing World

Platukyte, Simona 23 March 2016 (has links)
In the early 1990s, the United Nations (UN) recognized water as a finite resource to the entire ecosystem with an economic value that should be developed and managed based on the participatory approach using the Integrated Water Resource Management (IWRM) strategy. Many studies on water management practices have thus emerged in the developing world. Of particular interest to this work is the management of water through metering, price-setting, and rule enforcement in the rural setting in piped, community-owned water systems. There is very little published information regarding metering, enforcement experiments, and experiences in these systems. This is because metering and enforcement mechanisms are not typically included in rural piped community-managed water supply system design and water committee training schemes. Along with an increase in population growth and changing climate patterns, there is a burgeoning interest to manage demand and reduce non-revenue water (NRW) in urban utilities in developing countries. Metering is often the demand management tool considered because it has been reported to increase customer payment rates as well as social equity. Rural, community-managed systems often suffer high failure rates due to the lack of preventative maintenance, which maybe closely linked to customer dissatisfaction and non-payment of tariffs. The inclusion of a metering and enforcement program to such systems may help to address the problem of high rates of premature failure. An inclusion of a metering program for rural community-managed water supply systems is a non-trivial task in terms of cost as well as the system designer’s time, thus there is significant interest in ensuring such a program’s success. Many field workers may have familiarity with water system design but not specifically in the area of water flow metering and currently no beginner-level resources are publicly available. This work is ultimately intended to facilitate the inclusion of metering into rural, piped, community-managed water supply systems through: 1) compilation of technical information regarding metering which would be accessible to field practitioners and relevant to the rural community-managed setting, 2) a proposed decision-making tool to facilitate the selection of the most appropriate meter for the community, 3) proposed installation tips, and 4) suggested strategies for including metering into the community-management model. Objectives 1, 3, and 4 were pursued via review of industry, peer-reviewed, and field literature along with the author’s personal experience. Multiple criteria decision analysis (MCDA) was the method proposed for aiding in the selection of the most appropriate meter type. It was determined that four types of meters are used for residential metering in developed and developing urban utility-managed systems: the nutating disc, oscillating piston, multi-jet, and single-jet. The nutating disc and oscillating piston meters operate through a volumetric or displacement mechanism, while the single- and multi-jet meters function through a velocity or non-displacement mechanism. While a lot of variation between models of meters exists, there are fewer characteristics that can be used to differentiate between mechanisms. After applying the multiple-criteria decision analysis to aid in the selection of the most appropriate meter for a rural, community-managed systems, the nutating disc and oscillating piston types of meters were most preferred under the set of criteria chosen by the author for the purpose of example in this analysis. It is recommended that meter selection be performed on a site-specific basis with local stakeholder involvement for criteria determination. Meter installation is similar for all four types of meters and whichever type of meter is chosen, it should be protected from tampering. Increasing-block pricing is recommended to accompany metering in order to motivate water conservation. The size and price of the initial block of water should be determined according to the system’s operation and maintenance costs as well as users’ willingness to pay information. Field practitioners should prepare the community to take over the metering program by providing basic training to the users and selected meter readers/technicians.
24

Modellierung historischer Abflussverhältnisse für die Hochwasserprognose

Kirsch, Franziska, Pohl, Reinhard January 2011 (has links)
Um historische Durchflussangaben an Flüssen, die in die Hochwasserstatistik eingehen, überprüfen und bewerten zu können, werden 1-D- und 2-D-Wasserspiegellagenberechnungen unter Verwendung historischer morphologischer Daten durchgeführt. Die Methodik sowie ihre Möglichkeiten und Grenzen werden am Beispiel der Elbe im Stadtgebiet von Dresden erläutert.Es wird deutlich, dass die notwendigen Korrekturen auch Auswirkungen auf die Hochwasserstatistik und damit auf die Schutzgrade haben.
25

Computational Modeling of A Williams Cross Flow Turbine

Pokhrel, Sajjan January 2017 (has links)
No description available.
26

Řízení zásobní funkce nádrže s využitím metod umělé inteligence / Control of the reservoir storage function using artificial intelligence methods

Hon, Matěj January 2022 (has links)
The diploma thesis deals with flow prediction using artificial intelligence to control the storage function of the reservoir. It focuses on the control of storage function using combination of dispatching graphs and flow prediction. The work is divided into a methodological part and an application part. The methodological part contain describes how the acquisition of historical data, a description of the work of dispatching graphs and forecasting models. The application part contains flow forecasts and outflow control. A prediction model is based on the fuzzy method, and it is used to predict inflows. The calibration and validation of the prediction model is also described. Results of prediction model were evaluated. In next step the results of control method were evaluated and compared with result of dispatching graphs. The results of controlled method were satisfactory.

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