The present study involves experimental analysis of the modified Closed Wet Cooling Tower (CWCT) based on first and second law of thermodynamics, to gain a deeper knowledge in this important field of engineering in Iraq. For this purpose, a prototype of CWCT optimized by added packing under a heat exchanger was designed, manufactured and tested for cooling capacity of 9 kW. Experiments are conducted to explore the effects of various operational and conformational parameters on the towers thermal performance. In the test section, spray water temperature and both dry bulb temperature and relative humidity of air measured at intermediate points of the heat exchanger and packing. Exergy of water and air were calculated by applying the exergy destruction method on the cooling tower. Experimental results showed a significant performance improvement when using packing on the CWCT. It can be observed that the thermal efficiency for the CWCT with packing under a heat exchanger and CWCT with packing above the heat exchanger are approximately 40% and 25% higher than that of the CWCT without packing respectively. As another part of the experiment results, it is indicated that the exergy destruction is directly proportional to air flow rate, cooling water flow rate, inlet cooling water flow rate and inlet Air Wet Bulb Temperature (AWBT) whereas, it is inversely proportional with spray water flow rate. In comparison with the cooling capacity of the tower, it was found that the exergy destruction approximately less than 20%. Exergy efficiency behavior is inversely proportional with the behavior of the exergy destruction. Empirical correlations are obtained to predict water film heat transfer coefficient and air-water mass transfer coefficient considering the influences of operational parameters.
اهتمام العلماء العرب بالحروف مبينين معانيه موضحين مقاصده
That the Jewish minority in Iraq, were considered among the Iraqi people, building.
This paper presents a robust control method for the trajectory control of the robotic manipulator. The standard Computed Torque Control (CTC) is an important method in the robotic control systems but its not robust to system uncertainty and external disturbance. The proposed method overcome the system uncertainty and external disturbance problems. In this paper, a robustification term has been added to the standard CTC. The stability of the proposed control method is approved by the Lyapunov stability theorem. The performance of the presented controller is tested by MATLAB-Simulink environment and is compared with different control methods to illustrate its robustness and performance.
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Violence can be identified as an outreaching on others’ dignity,
freedom, properties, and life. Therefore, violent actions cannot be determined
only on materialistic attacks such as killing, beating, robbery, rape, and civil
wars, but it also includes the verbal attacks such as insult, threat, and cursing.
Violence against women can be identified as any bad actions that are
done against women, which lead to a physical or psychological harm, and
invade their safety and freedom whether these actions come from men or
women, against one woman or a group of women in special and general
places.
Before, the social, historical and lawful manners concentrated on
sexual distinction between the men and a woman, which
البنية الاقتصادية الاجتماعية للادارة الجديدة في الولايات المتحدة الامريكية
The research aimed at measuring the degree to which the accept their class environment in governmental & civil Kindergartens & it also aimed at knowing the differences between the dimensions of the measurement & the differences according to the kindergarten & class variables .
The researcher made a measurement for the class environment & it included five dimensions & the answering choices were three ( to a big extent , to some extent and no ) and after making sure that the measurement is usable , the researcher applied it on the sample which consisted of ( 212 )male & female children through the estimated answers of the teacher & the result was that there was an accep
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Bekanntlich hat jede Sprache ihre eigenen charakteristischen Besonderheiten. Davon ausgehend gibt es auch gewisse Unterschiede zwischen dem Arabischen und dem Deutschen. Zu den wichtigsten Gebieten der deutschen Grammatik gehören die zusammengesetzten Sätze, vor allem Satzgefüge mit den über- und untergeordneten Sätzen. Dazu gehören auch die Äquivalente der Nebensätze, besonders die Infinitiv- und Partizipialkonstruktionen.
Die vorliegende Recherche hat eine der grammatischen Strukturen des Arabischen und des Deutschen nämlich die dass-Sätze und Infintivsätze mit zu und deren Wiedergabemöglichkeiten in den beiden Sprachen zum Inhalt, weil die Infinitivsätze mit zu den Deutschlernenden beson
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