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.
Si le rire est censé être le propre de l'homme, il n'en est pas pour autant toujours signe d'intelligence. Qui n'a jamais eu honte d'avoir ri àune blague idiote ou méchante?
Il y a plusieurs façons de rire , ce qui fait que ce qui est comique pour les uns ne l'est pas pour les autres et que le comique réside moins dans l'objet ( situation, blague..) que dans le point de vue et dans l'interprétation que nous en ferons. " Le rire .. contient toutes les mélancolies humaines ([1]) ".
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إلى إامة مجتمع متماسك البنيان، وبناء فرد ذي شخصية متزنة، لا تعر التردد
مما توصل إليه البحث :
إن الدوافع النفسية تنفرد في تجسيد الأحاسيس والمشاعر في نتاج الشاعر , من خلال رؤيته لتلك الحالة , فتسهم في صورة المقارنة في التشبيه , فتبعث في المتلقي حالة التأمل والمقارنة بين الحالتين اللتين تجمع بين مكوناتهما صفة واحدة فتصل إلى حالة التلاحم , ويكون ذلك باعثا لرسم صورة التشبيه ال
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The distribution is one of the elements of the marketing mix key by which companies can to deliver their products through private channels to all customers in right time and right place to check though in which the levels desired by customer satisfaction, the and purpose of the discussion dealt with the preparation of analytical studies to explain the impact of live performance of distribution channels in achieve customer satisfaction in industrial companies, as well as the diagnosis and the reality of the research variables in companies under study and describe the kind of relationship between changers Home on the one hand and the relationship between the variables sub on the other hand, represe
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تهدف هذه المقالة إلى توضيح أخلاقيات العلم وضوابطه التي يجب على من يعمل في هذا المجال أن يكون متحلي بها حتى يحافظ على القيم والأخلاق الفاضلة والموروثة من الآباء والاجداد والنابعة من الصالحين والاخيار لديم ومة الحياة بأفضل وجه وكما يتمناه الكل وكذلك عدم تجاوز الحدود التي تؤدي إلى الأض ا رر بالمجتمع والبيئة . وتوضيح الحدود الغير مسموح بتجاوزها في مجال العلم والتكنولوجيا ومن هذه الأخلاقيات أو الضوابط التي يجب أن
... Show MoreAfter atour-For quite somtime,in the field of research and investingation on the economic aspects and the impact of her money is mportantin the evolution and emegece of the Islamic countres,especially including especially Morkhana him specimer nigh borhood the countries of the mashreq al islami,searhout,among other things summarilesas
After the fall of the Iraqi regime in the 9th of April 2003, and after the disintegration of the country, political and party political chaos that had never been witnessed before, has now taken over. In the past 2 years, the American military forces had a primary role in spreading this chaos and disorder by applying a set of wrong measures and policies. This chaos that is still affecting the iraqi people was completely ignored by the USA even 2 years after the occupation, no serious steps have been taken in order to bring back order and security, on the other hand, most of the government institutions and its forces were disintegrated, along with the decision made by Paul Bremer of dismissing all the iraqi journals and the workers of the
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Our research, entitled(Population and economic determinants of society and its impact in the history of contemporary Baghdad 1940-1960), dealt with a number of historical facts and events of the social, demographic and economic
The principal components analysis is used in analyzing many economic and social phenomena; and one of them is related to a large group in our society who are the university instructors. This phenomenon is the delay occurred in getting university instructor to his next scientific title. And as the determination of the principal components number inside the principal components depends on using many methods, we have compared between three of these methods that are: (BARTLETT, SCREE DIAGRAM, JOLLIFFE).
We concluded that JOLLIFFE method was the best one in analyzing the studying phenomenon data among these three methods, we found the most distinguishing factors effecting on t
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