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.
مجتمع مدني ام مجتمع اهلي ؟ دراسة لواقع المجتمع المدني في البلدان العربية
تزايد اهتمام الحكومات باختلاف أنظمة الحكم فيها والأفكار السياسية التي تؤمن بها، بالضرائب كأحد أدوات السياسة المالية، تسعى إلى أن تحقق من خلالها أهداف اقتصادية واجتماعية وسياسية فضلا" عن الأهداف المالية، إذ إن السياسة الضريبية تصاغ أهدافها باتساق وانسجام مع أهداف السياسة الاقتصادية بشكل عام، و إنما كانت الضريبة عام، ولما كانت الضريبة على هذا القدر من الأهمية فانه لم يكن مستبعدا" أن تحظى بعناية مشرعي ا
... Show Moreولد ابو بكر محمد بن زكريا الرازي في الري سنة 250هـ (864م) وتعمق في الطب والكيمياء والفلك والأدب والفلسفة وهو أحد مشاهير الاطباء في زمانه وهذا هو السبب الذي دعاه لأن يتنقل من بلاط الى اَخر , ولم ينعم بالأستقرار في حياته بالنظر الى تقلب الأهواء والاُمراء وأضطراب الأحوال السياسية . قام برحلات كثيرة , وعهدت اليه ادارة بيمارستان ( مصح ومشفى ) الري ثم قام بهذه المهمة نفسها في بغداد.
لقب بـ( طبي
... Show MoreContemporary art has been widely affected by technology, and ceramics production is no exception. As an ancient art that originates from clay and other humble materials found in the ground, ceramics is considered one of the most adaptable art forms. Once it is realised how flexible ceramics as a material is, it can be easily altered into endless forms and shapes. Therefore, it is vital for ceramics practitioners to find a relationship between this wonderful material and the media of contemporary art, culture and modelling software or technology in general so that they can take their deformable art pieces to a whole new level. Such a relationship is worth investigating. Thus, for the purposes of this research, several ceramic pieces were
... Show MoreThe reasons for the totality are varied and multiple, some of which are attributed to the methods of the Arabic language as the participant
Verbal and omnipotent differences in the oud of conscience, which are comprehensive reasons for language in all
And some of these reasons are due to the sciences of the Qur'an, such as cessation and initiation
The explanation of the explanation for the multiplicity of words and differences in them, which necessarily led to a dispute jurisprudence
Linked to the origin of disagreement in the interpretation of the totality and its orientation and understanding and to summarize this subject and diverge
Parts and vocabulary did not receive the necessary care and did not absorb the lesson an
يستعرض المقال تطور مؤتمرات القمة العربية منذ أول قمة عام 1946 حتى قمة المنامة 2024. ويسلط الضوء على القضايا التي تناولتها القمم، مثل فلسطين، سوريا، والسودان. كما يشير إلى أهمية قمة جدة 2023 التي شهدت عودة سوريا للجامعة العربية. وتستعد بغداد لاستضافة القمة الرابعة والثلاثين في 17 مايو 2025، وسط تحديات إقليمية كبيرة. وتعد القمة فرصة للعراق لاستعادة دوره العربي وتعزيز التعاون المشترك لمواجهة الأزمات السياسية والاقتصادي
... Show Moreيمر عالمنا المعاصر اليوم بمرحلة من التطور والتغيير السريعين لم يسبق له أن مر بهما فـي تاريخ البشرية ، ويشمل مظاهر الحياة الأنسانية والأقتصادية والعلمية والتربويـة والنفسية وغير ذلك . وتختلف سرعة هذا التغيير من مجتمع الـى مجتمع آخر , وأدى هذا الى تراكم كميات كبيرة من المعلومات .
لقد أكد الكثير مـن التربويين أن التطور التكنولوجي فـي ال
... Show MoreThe Negro minority in the United States is associated with social injustice,
political deprivation, and economic oppresion. Its members felt that they are
second-class citizens, and that the acceptance of such status will lead to the
continual oppresion of the Whites upon them. As a result, the educated community
adopted a process to put a framework to their opposition to the former's injustice.
This organised framework is exemplified in the "Niagara Movement," which is
regarded as the first national organisation for Negros. The topic of this study is
chosen due to its historical and political significance.
The study consists of an introduction and five sections. The first section
addresses the preliminaries an
Abstract The present research aims to know the range of Knowledge and the using of teachers of aerography department in colleges of Education to Applicant electronic Learning , So the Sample of the research reached (129) teacher, of the university of Boghdad and Al mustansiria who were chosen by using Randomly sample , and applauding questioner for these perpos that prepared by muhamed bn Ghazi Al Judi – and by using the T-test for one sample and person correlation formula as a statistical means. The research reached to the results which indicate that weakness knowledge and using the theachers of geographe department to the application electronic learning. And according this the researcher put some Recommendation and suggestions.
... Show More