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.
تُعد دراسة أعلام الفكر العربي والإسلامي من أهم الدراسات التاريخية ولا يمكن للأمم المتحضرة أن تنسى علمائها ومفكريها لما لهم من دور كبير في حاضر الأمة ومستقبلها و تاريخنا الإسلامي يحفل بالعديد من العلماء ورجال المعرفة الذين ساعدوا على تقدم ورقي العرب والمسلمين على الأمم الأخرى0
Addition of bioactive materials such as Titanium oxide (TiO2), and incorporation of bio inert ceramic such as alumina (Al2O3), into polyetheretherketone (PEEK) has been adopted as an effective approach to improve bone-implant interfaces. In this paper, hot pressing technique has been adopted as a production method. This technique gave a homogenous distribution of the additive materials in the proposed composite biomaterial. Different compositions and compounding temperatures have been applied to all samples. Mechanical properties and animal model have been studied in all different production conditions. The results of these new TiO2/Al2O3/PEEK biocomposites with different
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تعتبر لعبة كرة اليد من الالعاب الفرقية، وان هذه اللعبة تستند الى قاعدة اساسية وهي الاداء الصحيح للمهارات، وللتقدم في هذه اللعبة يجب تعلم وأتقان اداء المهارات للوصول الى مستوى افضل للتعلم، من خلال الدور الذي يؤديه اسلوب نموذج كولب لأنماط التعلم (التكيفي) الذي يعمل على تحديد اسلوب التفكير والمفضل لكل فرد وتاثيره في تعلم مهارة الطبطبة للطالبات، اذ يعمل على ايصال المعلومات والافكار الخاصة باداء المهارة وحس
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This research aimed to diagnose the perception based on Telecommunications of Iraq to the importance of activating knowledge management marketing in possession, as well as Indication of impediments to activate the management of marketing knowledge in the researched companies, also aimed to show the extent of the existence of significant differences in perception based on Telecommunications Iraqi importance of activating the management marketing knowledge in possession. To achieve the objectives of this research, the questionnaire was developed and distributed to a sample of telecommunications companies in the city of Sulaimaniya, was selected on the criterion according to the company's life in terms of seniority in the telecommunication
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Background: Laparoscopic sleeve gastrectomy (LSG)is derived from the biliopancreatic diversion with duodenal switch operation(BPD-DS). Specific and potentially severe complications of LSG are bleeding from the staple line and staple line leakage (SLL). A staple line leak may result in severe morbidity with potential sepsis and multi- organ failure.
Objectives: To review our experience with the definitive surgical management of staple line leak Post sleeve gastrectomy and its outcomes.
Patients and methods: retrospective review of patients who underwent definitive surgical treatment of staple line leak post sleeve gastrectomy from May 2014 till June 2016 at Saint Raphael center of morbid obesity, Primary surgery was laparoscopic sle
Abstract
The analysis of Least Squares: LS is often unsuccessful in the case of outliers in the studied phenomena. OLS will lose their properties and then lose the property of Beast Linear Unbiased Estimator (BLUE), because of the Outliers have a bad effect on the phenomenon. To address this problem, new statistical methods have been developed so that they are not easily affected by outliers. These methods are characterized by robustness or (resistance). The Least Trimmed Squares: LTS method was therefore a good alternative to achieving more feasible results and optimization. However, it is possible to assume weights that take into consideration the location of the outliers in the data and det
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تتطلب عملية التنمية الاقتصـادية في الدول النامية مبالغ كبيرة من رؤوس الأمـوال اللازمة لتنفيذ البرامج والخطط الاقتصادية، ولما كانت الاسـتثمارات التي تنفذها هذه الدول خلال حقبة معينة، تزيد على ما تم تحقيقه من موارد مالية محلية، فلابد أنْ يمول الفرق من خلال انسياب صافٍ لرأس المال الأجنبي (قروض ومساعدات) إلى الداخل خلال المدة نفسها، لغـرض سَدّ الفجوة في المـوارد المحلية المعدة للاسـتثمار، وعانت بعض د
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The aim of the thesis is to estimate the partial and inaccessible population groups, which is a field study to estimate the number of drug’s users in the Baghdad governorate for males who are (15-60) years old.
Because of the absence of data approved by government institutions, as well as the difficulty of estimating the numbers of these people from the traditional survey, in which the respondent expresses himself or his family members in some cases. In these challenges, the NSUM Network Scale-Up Method Is mainly based on asking respondents about the number of people they know in their network of drug addicts.
Based on this principle, a statistical questionnaire was designed to
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A group of acceptance sampling to testing the products was designed when the life time of an item follows a log-logistics distribution. The minimum number of groups (k) required for a given group size and acceptance number is determined when various values of Consumer’s Risk and test termination time are specified. All the results about these sampling plan and probability of acceptance were explained with tables.