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Design Of Water Distribution System By Optimization Using Reliability ConsiderationsAkdogan, Tevfik 01 June 2005 (has links) (PDF)
ABSTRACT
DESIGN OF WATER DISTRIBUTION SYSTEM BY OPTIMIZATION USING RELIABILITY CONSIDERATIONS
Akdogan, Tevfik
Department of Civil Engineering
Supervisor : Assoc. Prof. Dr. Nuri Merzi
April 2005, 91 pages
In spite of a wide research, design of water distribution networks are not realized using optimization techniques. One reason for this fact is, design of water distribution networks is evaluated, mostly, as a least-cost optimization problem where pipe diameters being the only decision variables. The other motivation for preferring the traditional modeling practice is that, existing optimization algorithms are not presented to the user as friendly as it should be.
In fact, water distribution systems are very complex systems such that it is not easy to obtain least-cost design systems considering other constraints such as reliability, in addition to classical constraints related to hydraulic feasibility, satisfaction of nodal demands and requirement of nodal pressures. This study presents a user-friendly package concerning the design of water distribution networks by optimization using reliability considerations / this works employs the algorithm proposed by Goulter and Coals (1986). At the end, a skeletonized network design is offered / various costs are estimated in regard to the degree of reliability.
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Experimental Investigation Of Energy Dissipation Through Triangular ScreensGungor, Endam 01 June 2005 (has links) (PDF)
ABSTRACT
EXPERIMENTAL INVESTIGATION OF ENERGY DISSIPATION THROUGH TRIANGULAR SCREENS
Gü / ngö / r, Endam
M.Sc., Department of Civil Engineering
Supervisor: Assoc. Prof. Dr. Zafer BozkuS
Co-Supervisor: Prof. Dr. Metin Ger
May 2005, 82 pages
For the present study, a series of experimental works are executed to dissipate energy through triangular screens. Recent studies have shown that the implementation of the screen for energy dissipation is an effective way to extract out the excessive energy of water downstream of small hydraulic structures located in rivers of relatively negligible sediment content. In the present study, double screen arrangement with a porosity of 40% is used. The inclination angle of the screens is opted as 60 degree. The major parameters for the present study are upstream flow depth, location of the screen together with the supercritical upstream flow Froude number for a range covering from 7.5 to 25.5. The gate opening simulating a hydraulic structure is adjusted with various heights of 1 cm, 1.25 cm, 1.6 cm, 1.7 cm, 2 cm, 2.5 cm, 2.7 cm, 3.2 cm and 3.3 cm during the study. The results of the experiments show that the triangular screen configuration with the same pore geometry has no significant additional contribution on the energy dissipation as compared to vertically placed screens.
Keywords: Screen, energy dissipation, triangular configuration, porosity, hydraulic jump, supercritical flow.
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Non-darcian Flow In A Fractured AquiferAltinors, Adnan Altay 01 August 2005 (has links) (PDF)
Non-Darcian flow in a finite fractured aquifer is studied in this thesis. A stream bounds the aquifer at one side and an impervious stratum at the other. The aquifer consists of fractures capable of transmitting water rapidly and porous blocks which mainly store water. Unsteady flow in the aquifer due to a sudden or a gradual rise in the stream level is analysed by the double-porosity conceptual model. Governing equations for the flow in fractures and blocks are developed using the continuity equation. The fluid velocity in fractures is often too high for the linear Darcian flow so that the governing equation for fracture flow is modified by Forcheimer&rsquo / s equation which incorporates a nonlinear term. Governing equations are coupled by an interaction term that controls the quasi-steady state fracture-block interflow. Governing equations are solved numerically by the Crank-Nicolson implicit scheme. The numerical results are compared to the analytical results for the same problem which assumes Darcian flow both in fractures and blocks. Numerical and analytical solutions give same results when Reynold&rsquo / s number is less than 0.1. The effect of non-linearity on the flow appears when Reynold&rsquo / s number is greater than 0.1. The larger the piezometric head gradient, the higher the flow rate and, thus, higher the non-linearity is. The effect of aquifer parameters on the flow is also investigated. The proposed model and its numerical solution is a unique application of non-linear flow models to the fractured aquifers. It can be used in predicting water levels in fractured aquifers and evaluating time dependent flow rates in the analysis of recession hydrographs.
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Discharge Predictions Using Ann In Sloping Rectangular Channels With Free OverfallOzturk, Hayrullah Ugras 01 October 2005 (has links) (PDF)
In recent years, artificial neural networks (ANNs) have been applied to estimate in many areas of hydrology and hydraulic engineering. In this thesis, multilayered feedforward backpropagation algorithm was used to establish for the prediction of unit discharge q (m3/s/m) in a rectangular free overfall. Researchers&rsquo / experimental data were used to train and validate the network with high reliability. First, an appropriate ANN model has been established by considering determination of hidden layer and node numbers related to training function and training epoch number. Then by applying sensitivity analysis, parameters involved in and their effectiveness relatively has been determined in the phenomenon. In the scope of the thesis, there are two case studies. In the first case study, ANN models reliability has been investigated according to the training data clustered and the results are given by comparing to regression analysis. In the second case, ANN models&rsquo / ability in establishing relations with different data clusters is investigated and effectiveness of ANN is scrutinized.
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Management Of Reservoir Sedimentation Case Studies From TurkeyCetinkaya, Oguz Kagan 01 February 2006 (has links) (PDF)
Siltation is becoming a big problem as the dams get older all over the world. Conservation and sustainable management of existing reservoirs is gaining more importance than constructing new dams. In this study the program RESCON, which is outcome of a World Bank sponsored project, has been used to examine sediment removal strategies (flushing, hydrosuction sediment removal, dredging and trucking) for four dams of Turkey namely Ç / ubuk I Dam, Bayindir Dam, ivriz Dam and Borç / ka Dam. Sediment measurements are made by governmental agencies in Turkey. In this study characteristics of these measurements will be presented for the future sediment related studies. Then sediment removal strategies which were used in RESCON will be introduced. Evaluation of RESCON results have been made and compared with previous studies for verification except Borç / ka Dam, since it is under construction.
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Social And Economic Impacts Of The Southeastern Anatolia ProjectErcin, Ali Ertug 01 June 2006 (has links) (PDF)
This thesis is an assessment of socio-economic development of Southeastern Anatolia Region of Turkey after GAP Project. The aim of this study is to analyze and discuss impacts of the GAP Project and to evaluate achievements of the most important sustainable development project of Turkey.
Several social and economic indicators, like demographic structure, education, health, financial figures, industry, agriculture and energy, have been analyzed and evaluated in order to obtain reliable and realistic conclusions.
The main conclusion of this thesis states that Southeastern Anatolia Region has developed both socially and economically with the impacts of GAP Project. Rapid economic growth, increased agricultural and industrial activities are the evidences of this development. However, another conclusion of the study indicates that the achievements of GAP cannot ensure the expected socio-economic development of the Region. This conclusion shows the necessity of questioning the success of the governance and execution of the GAP Project.
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Bandwidth regulation and performance enhancements for Open-iSCSI networked storageZhang, Yongjian 11 1900 (has links)
Virtual machines are gaining a growing importance in modern business IT infrastructure. They facilitate multiple operating system instances on one physical host, which provides more efficient use of the computing power of the physical host but increases the amount of network traffic as well. To avoid potential network congestion and prioritize link resource usage in a virtual machine system, we propose a bandwidth regulation scheme. Extensive evaluation demonstrates that this bandwidth regulation scheme is accurate and effective. In addition, we resolved a drastic performance degradation of the Open-iSCSI initiator. We thoroughly tested the performance of the Open-iSCSI initiator and three modified versions under two methods of setting the TCP send buffer size - statically and dynamically. Based on these results, we propose a performance tuning scheme, which can enable users of Open-iSCSI, especially those using Open-iSCSI over a long fat network, to achieve significant throughput gains.
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Women of childbearing age: dietary patterns and vitamin B12 statusXin, Liping January 2008 (has links)
From conception the dynamic balance between nutritional and activity factors play a role in the accumulation of risk for future disease. Maternal nutrient balance and the subsequent dietary pattern of the family set the path for the growth and development of the individual and therefore also for their offspring. There is strong evidence from studies in India that mothers who have a low vitamin B12 status, but high folate, will have children with higher adiposity and more cardiovascular risk factors than those with adequate B12. The B12 status is closely linked to the dietary pattern particularly the consumption of red meat which has a high B12 content. In New Zealand there are an increasing number of Indian migrants. Vegetarianism is also practiced by an increasing number including young women. In addition, there is a high rate (up to 60%) of unplanned pregnancies in New Zealand. In the 1997 New Zealand National Nutrition Survey (NNS97) report, vitamin B12 intake appeared adequate for the New Zealand population and breakfast cereals were reported as one major dietary source of B12. Cereals in New Zealand however, were not fortified with B12 and there was an error in the FOODfile™ data entries for B12 in some cereals. The raw data of reported B12 intakes in the 24-hour diet recall (24HDR) of NNS97 was reanalysed at the individual level by subtracting the B12 derived from breakfast cereals and applying the 2005 revised estimated average requirement (EAR) value. The possible prevalence of B12 insufficiency was 2.4 times that originally reported by the NNS97, translating into a prevalence of up to 27% of the population sampled. This analysis was limited as it was not adjusted for day-to-day variance or to the New Zealand population. This apparently high prevalence of risk for inadequate B12 intake in the surveyed individuals required confirmation that the B12 intake from 24HDR and also a 7-day diet diary (7DDD) was a valid assessment of B12 status. The group of particular interest is women of childbearing age (18-50y) with a range of eating patterns. Thirty eight women aged 19-48y; 12 non-red-meat-eaters (5 Indians vs. 7 non-Indians) and 26 red-meat-eaters (1 Indian vs. 25 non-Indians) participated in this validation study. Anthropometry and hand-to-foot bioelectrical impedance (BIA) were measured on the same day as a 24HDR was recorded. Fasting serum lipids, glucose, haematological parameters, and serum B12, holotranscobalamin II (holo-TC II, a specific B12 biomarker), and folate concentrations were measured. Foods eaten and time spent in physical activity during the following 7 days were extracted from 7DDD and 7-day physical activity diary (7DPAD). There was no significant correlation between dietary intake (24HDR or 7DDD) and biomarkers for B12 status. Indians reported lower mean daily B12 intakes in 7DDD than non-Indians (1.6 vs. 4.5 μg/day, p<0.001) and this was confirmed by Indians’ significantly low serum B12 (203 vs. 383 pmol/L, p=0.04) and holo-TC II (35 vs. 72 pmol/L, p=0.02) concentrations compared to non-Indians. A similar pattern was found between non-red-meat-eaters and red-meat-eaters in daily B12 intake in 7DDD (2.3 vs. 4.8 μg/day, p<0.001) and in B12 biomarkers (serum B12, 263 vs. 397 pmol/L, p=0.01; holo-TC II, 43 vs. 77 pmol/L, p<0.005). Non-red-meat-eaters reported significantly higher daily folate intake in 7DDD (359 vs. 260 μg/day, p=0.01) than red-meat-eaters but no significant difference was found in serum folate concentration between these groups (29 vs. 24 pmol/L, p=0.10). Indians/non-red-meat-eaters also reported lower daily protein intake and higher percentage of total energy from carbohydrate in 7DDD compared to non-Indians/red-meat-eaters but total reported energy intake tended to be under-reported and physical activity over-reported when assessed against estimated basal metabolic rate (BMR). Body composition varied by dietary pattern. Indians/non-red-meat-eaters had higher body fat percentage (BF %) and weaker grip strength than non-Indians/red-meat-eaters. In addition, Indians had a significantly higher waist-to-hip ratio (WHR) than non-Indians. Overall, the whole group reported that they were inactive. The median time spent in moderate, high and maximal intensity activities was only 19 minutes a day, which did not meet the NZ guideline for adults of 30 minutes a day. In this small study nutrient analysis of diet by 24HDR or 7DDD, was not a reliable or accurate way to assess B12 insufficiency. Questions about dietary patterns such as “do you eat red meat”, and taking ethnicity into account could more easily identify the at risk population. Supplementation and/or fortification of B12 should be considered before pregnancy.
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Imaging-based dynamic liver testing : studies of segmental hepatic parenchymal function and biliary flow using dynamic ⁹⁹Tcm-HIDA SPECT /Jonas, Eduard, January 2002 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 5 uppsatser.
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The synthesis and characterisation of Langmuir-Blodgett film forming TCNQ adductsBradley, Christopher Simon January 1999 (has links)
Substitution reactions of TCNQ (7,7,8,8-tetracyanoquinodimethane) with suitable electron donor moieties extended the range of gamma-bridged adducts R(4)Q3CNQ and R(4)P3CNQ of which the short chain Z-beta-(l-butyl-4'-quinolinium)-alpha-cyano-4-styryldicyanomethanide (C[4]H[9](4)Q3CNQ) is a typical example. These zwitterionic D-pi-A materials (where D and A are electron donors and acceptors respectively) exhibit properties such as solvatochromism, molecular rectification and second harmonic generation. Further synthetic work concentrated on modifying the donor, the acceptor and the substitution position within these zwitterions to create a series of diverse materials for non-linear optic research. Modification of the picolinium and quinolinium systems where the TCNQ substitution is in the alpha-position, has created the extensive analogous series-R(2)Q3CNQ and R(2)P3CNQ, their properties being compared and contrasted to the original gamma-bridged adducts. The behaviour of the materials on the subphase and their resultant Langmuir-Blodgett (LB) film fabrication was studied. The abrupt change in molecular orientation in LB films of the gamma-bridged adducts occurring at R= C[15]H[31] and above was not seen in the more flatly orientated alpha-bridged adducts. Further characterisation of the LB films was performed using reflectance-absorption infrared spectroscopy (RAIRS) and surface plasmon resonance (SPR).A number of N-alkylpyridinium benzimidazolate betaine derivatives and the related betaine-TCNQ adducts were prepared and their LB film forming properties were studied.
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