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.
كانت االمثمة ومازالت الػسيمة الػحيجة واالىع في ايزاح القػاعج الشحػية قجيسا وحجيثا ، فالسثال ىػ الصخيقة التي بػاسصتيا يفيع الستعمع ما يخيج ان يػصمو السعمع ، فالذخح الكثيخ والدخد ال يػصل الى بيان القاعجة مالع يعدز باالمثمة . وليحا فان اختيار السثال السشاسب في السكان السشاسب ال يتع بصخيقة عذػائية اذا يشبغي ان يكػن السثال ذا معاييخ ومػاصفات تشاسب السقام الحي قيمت فيو . مغ ىشا جاء ىحا البحث ليبيغ ما السػاصفات الت
... Show MoreThe literature in general, such as the spanish literature as british literature presence lot of literary figures giant that managed its continuing work that leaves lasting impression and clear in all fields of literary world throughout history, among these writers giants can remind great writer spanish (Miguel de Cervantes) and the great british writer (William Shakespeare), this study is about them.
We can say that there are a lot of studies , works and gossip , whether literary or non- literary show how the close relationship that bound both Cervantes and William Shakespeare, although they did not meet personally never, it was not able to critics that the sweep of the differences and similarities that was between the two, becau
... Show Moreدور المراكز البحثية في الحياة السياسية وصنع القرار السياسي الخارجي الامريكي
Long memory analysis is one of the most active areas in econometrics and time series where various methods have been introduced to identify and estimate the long memory parameter in partially integrated time series. One of the most common models used to represent time series that have a long memory is the ARFIMA (Auto Regressive Fractional Integration Moving Average Model) which diffs are a fractional number called the fractional parameter. To analyze and determine the ARFIMA model, the fractal parameter must be estimated. There are many methods for fractional parameter estimation. In this research, the estimation methods were divided into indirect methods, where the Hurst parameter is estimated fir
... Show Moreتعد ظاهرة الإتجار بالنساء جريمة من الجرائم ضد الأنسانية لما تنطوي على عدوان صريح وواضح على القيم الأنسانية والجماعات البشرية اذ تجعل من النساء سلعة رخيصة ومحلا للعرض والطلب، يمكن تداولها واستغلالها بالوسائل كافة غير المشروعة، فعلى سبيل المثال ان الاتجار بالنساء والأطفال لأغراض الدعارة والاستغلال الجنسي وبيع الأعضاء البشرية والزواج القسري والاستغلال السيء للمهاجرين بصفة غير شرعية، كلها تعد جانباً من جوان
... Show MoreThe scientific abandonment of the most important places of education and science in the Happy Yemen, which Manfred them from the rest of the Islamic Alomassar such kind of places Education existence, has contributed to a variety of factors paved the way for the emergence and originated scientific migration in the (fifth century AH / atheist century AD), and was in the forefront divisions witnessed by the Zaidi sect to if divided into three teams are (Almpartyah and inventor and Husseiniya) Because of differences doctrinal debates Pima including a heated end the fighting of the conflict between the parties,
يُعدّ الأشخاص ذوو الإعاقة أكبر أقلية في العالم وأكثرها حرمانًا، حيث تشير الإحصاءات إلى أن نحو مليار شخص، أي ما يعادل 15% من سكان العالم، يعانون من بعض أشكال الإعاقة، مع تزايد معدلاتها في البلدان النامية. وتشير الدراسات العلمية إلى أن ذوي الإعاقة قادرون على مزاولة العمل بإتقان ومثابرة، بل وقد تتفوق مهاراتهم أحيانًا على مهارات الأشخاص غير المعاقين، إذا تم اختيار العمل المناسب لقدراتهم ومواهبهم. كما أن حق العمل
... Show MoreDue to the importance of the word and because it is the basic building block from which speech is formed, it has become the subject of the attention of many scholars, ancient and modern, especially the Qur’anic vocabulary, which scholars dealt with in various branches of the Arabic language
تعد دراسة التراث العلمي العربي من الدراسات التي تلقي الضوء على التطور التاريخي للعلوم العربية وما أنجزته العقلية العربية في هذا الميدان للمدة التاريخية التي ابتدأت بعصر صدر الإسلام وانتهت بالخلافة ويرى الكثير من العلماء سواء كان