Dams and reservoirs located near populated areas represent a potential risk in the event of uncontrolled release of the reservoir water due to earthquake damage, endangering the people and properties. In the present work, the seismic performance of concrete gravity dams is studied numerically using commercially Finite Element based software ADINA (Automatic Dynamic Incremental Nonlinear Analysis). The study gives deep insight into the procedure of analysis and safety evaluation of concrete gravity dams, as well as improving its stability under earthquake loading. In the present study, the horizontal component of North Ridge earthquake was selected for analysis. The study covers a range of parameters including the effect of earthquake horizontal acceleration component, substrate soil type and strength properties of soil on the stability of concrete gravity dams. The behavior of upstream water surface under seismic shaking was also considered in the research.The results indicated that the relative uplift force, Ur, is linearly proportion to earthquake intensity. On contrary, Ur, decreases as the relative height of water in the reservoir, Hw/H, increases. The factors of safety, F.S, against overturning and sliding decrease with increasing the earthquake intensity. It was also found that sliding was the governing factor against failure.

Thermoelectric generators (TEGs) and their applications have gained momentum for their ability to use waste thermal energy. More contemporary technology must offer more exceptional energy-efficient applications at a lower cost. New technology must also have an ability to generate electric power through the conversion of wasted heat. The TEG has demonstrated its efficiency and how it can offer increased potential by adding an MPPT algorithm to increase the power flow while decreasing the cost of operation. The limitations can be offset by the use of lower cost manufacturing materials and automated systems in the TEG units. It is also important to note the cost per watt found in using a thermoelectric generator is estimated to be $1/W for an installed device. To achieve this goal, the optimum operating point should be monitored by DC to DC converters. The DC to DC converters should also be driven through a generated pulse using an MPPT algorithm.

No abstract

A number of embankment dams have failed or suffered major deformations during earthquakes. Numerical modeling methods can provide a powerful tool to predict the response of dams to earthquake loading. In the present work, the seismic performance of rockfill dams is numerically studied using the software ADINA (Automatic Dynamic Incremental Nonlinear Analysis) based on finite element method. The study is carried out to investigate the analysis procedures and safety evaluation of rockfill dams, and to improve its stability under earthquake loading. The study also investigates the generation and dissipation of pore water pressure generated within the dam clay core, the effect of earthquake horizontal acceleration component, and upstream water level on the stability of rockfill dams. Results indicated that large deformations took place within the clay core of the rockfill dam that consequently caused large crest settlements accompanied by relatively high generation of pore water pressure within that core. Moreover, the crest vertical displacements which can be used as an index of dam stability were relatively large enough in some cases to be more than freeboard that leads to overtopping.

This work presents the results of a laboratory study aims to improve the inlet of the pipe syphon to decrease the head losses resulting from the sudden contraction in the pipe. Box-type wing walls are considered upstream and downstream. Theoretical and experimental studies were conducted.For experimental study models with different cutting angles, measured from vertical axis, of pipe inlet ( 1 = 0 O , 15 O , 30 O , 45 O , and 60 O ). The pipe syphon was tested under different discharges (Q = 7.28 to 57.20 lit./sec). Different downstream submergence ratios (Hd /D = 0.0, 0.25, 0.50, 0.75, and 1.0) were considered. Dimensional analysis is employed to get the relationships between the different factors affecting the head losses through the syphon. The results of the study led to practical recommendations that are useful in the design of syphon inlet with low head losses.