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This paper is aimed at proposing a new design of a corona-discharge based electrostatic motor with a cylindrical rotor made from aluminum foil and multi copper strip stator electrodes. The stator electrodes are alternately stressed positively and negatively. The onset voltage of corona discharge is calculated based on the condition of discharge sustenance at stator electrodes. The corona currents emitted from positively and negatively stressed electrodes are calculated being dependent on the applied voltage and motor geometry. This calls at first for calculation of the spatial distribution of electric field within the motor volume using the accurate charge simulation technique. The calculated corona onset voltage and current-voltage characteristics of the motor agreed reasonably with those measured experimentally for three motors built-in the laboratory. The dependency of the motor speed on the applied voltage is reported for the different investigated motors.

This paper is aimed at proposing a new design of a corona-discharge based electrostatic motor with a cylindrical rotor made from aluminum foil and multi copper strip stator electrodes. The stator electrodes are alternately stressed positively and negatively. The onset voltage of corona discharge is calculated based on the condition of discharge sustenance at stator electrodes. The corona currents emitted from positively and negatively stressed electrodes are calculated being dependent on the applied voltage and motor geometry. This calls at first for calculation of the spatial distribution of electric field within the motor volume using the accurate charge simulation technique. The calculated corona onset voltage and current-voltage characteristics of the motor agreed reasonably with those measured experimentally for three motors built-in the laboratory. The dependency of the motor speed on the applied voltage is reported for the different investigated motors.

This paper is aimed at proposing a new design of a corona-discharge based electrostatic motor with a cylindrical rotor made from aluminum foil and multi copper strip stator electrodes. The stator electrodes are alternately stressed positively and negatively. The onset voltage of corona discharge is calculated based on the condition of discharge sustenance at stator electrodes. The corona currents emitted from positively and negatively stressed electrodes are calculated being dependent on the applied voltage and motor geometry. This calls at first for calculation of the spatial distribution of electric field within the motor volume using the accurate charge simulation technique. The calculated corona onset voltage and current-voltage characteristics of the motor agreed reasonably with those measured experimentally for three motors built-in the laboratory. The dependency of the motor speed on the applied voltage is reported for the different investigated motors.

This paper is aimed at proposing a new design of a corona-discharge based electrostatic motor with a cylindrical rotor made from aluminum foil and multi copper strip stator electrodes. The stator electrodes are alternately stressed positively and negatively. The onset voltage of corona discharge is calculated based on the condition of discharge sustenance at stator electrodes. The corona currents emitted from positively and negatively stressed electrodes are calculated being dependent on the applied voltage and motor geometry. This calls at first for calculation of the spatial distribution of electric field within the motor volume using the accurate charge simulation technique. The calculated corona onset voltage and current-voltage characteristics of the motor agreed reasonably with those measured experimentally for three motors built-in the laboratory. The dependency of the motor speed on the applied voltage is reported for the different investigated motors.

Hybrid Renewable Energy System (HRES) is an attractive system for stand-alone electrification in remote areas. The hydrokinetic power avoids all the disadvantages of hydropower, unlike dams that have obstructed the natural water flow and ended up displacing animals and people. The main objective of this work is to provide a feasibility study of using SMART MONOFLOAT** hydrokinetic power in hybrid photovoltaic (PV)/HKT/diesel/battery system to satisfy the electrical energy needs for the selected rural households in Naga Hammadi, Egypt in this study. The SMART MONOFLOAT hydrokinetic turbine has been used as it was developed to produce a maximum amount of electrical power with the kinetic energy of flowing water. The well-known Hybrid Optimization of Multiple Electric Renewables (HOMER) software is used as a software tool in this study. The 22-year monthly average solar radiation data of the selected rural households in Naga Hammadi, located at latitude of 26.013 and longitude of 32.32 was obtained from National Aeronautics and Space Administration (NASA) database. The monthly average current velocity data in this study, was collected for a single year during 1991 after the construction of the Aswan Dam in 1904. According to the simulation results in this work, it was found that the optimum HRES consisting of; 90 kW of PV panels, 90 kW of HKTs, 22 kW of diesel generators, 60 kW of power converters and 225 batteries. In addition to, a great reduction in greenhouse gases emission during the project lifetime could be achieved in the optimum system.

Abstract Drilling and blasting operation are an essential and integral part of mining cycle/process. They are almost employed in all mining methods (e.g., surface and underground works) as well some civil engineering projects (e.g., dams, roads construction and tunnel excavation). In feasibility studies (e.g., planning and preliminary cost estimation), the rock penetration rate (e.g., drillability) is used as a tool to predict the rock mass strength properties/characteristics. This paper examines the relationship between strength properties of selected rocks in Egypt and their drillability. Six natural rock types; were selected from different locations in the country, and another five artificial rocks; prepared in the lab with different composition, were tested in the laboratory for uniaxial compressive strength, tensile strength, shear strength, hardness (e.g., point load strength and impact strength) and rate of penetration. The regression equation is then established from the relationship between strength properties of rock and the penetration rate. The results revealed that strong correlation exists between penetration rate and compressive and tensile strength with correlation coefficient of R2 ≥ 0.75 for both exponential and logarithmic functions. For Barazilian tensile strength, the correlation coefficient was of R2 ≥ 0.7. The relationship between specific energy (SE) and rock strength properties are also presented and discussed in this study, where the results showed strong correlation.

In such a hard water situation in Egypt, in which we are facing a serious scarcity problem in our needs of water, we as water engineers have to adapt all the water measuring tools to perform accurate as maximum as possible. Since such tools are exciting everywhere along the very long, and complicated irrigation, and drainage systems on the network, in the forms of weirs, regulators, waterfalls, and others. The accuracy of such measuring structures is of great important in saving the water, and minimizing the overuse water. Owing to the simplicity, low cost, and its wide suitability for all types of waterways, we decided to investigate the clear over-fall weir as one of the most popular tools usually used for measuring the discharge in open channels. As the top edge geometry condition is an important parameter affecting the accuracy performance of such weirs, the present study investigates different top edges geometry conditions. Five shapes of the front weir top edge will be tested to point out the most effective shape in increasing the coefficient of discharge, and hence improving the discharge measuring efficiency. After that, the same tested edge shapes with the front edge, will be tested with the behind the top weir edge to fix the most compatible shapes may be used in both front, and behind top edges in achieving the optimum discharge measuring accuracy. An additional weir model with sharp edges in both fronts, and behind top edges will be tested under the same hydraulic conditions as a reference for comparison purposes. Experiments will be carried out using a horizontal testing laboratory flume 13.0m long, 0.30m wide, and 0.30m height in the Irrigation