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.
Abstract
The study deal with two main variables:- the dimensions of distribution, and the customer loyalty . the researcher has chosen samples of Iraqi newspapers like (AL Sabah, AL Mada, AL Bayna aljdeida newspaper), because this product depends greatly on the consumption of customers so as to achieve the success. After studying the dimensions of these variables ( cost, flixibilty & deliver time ) which concerns the distribution, and for these dimensions ( marketing relationship, customer perception, customer experience, brand, & product quality) which relate to the customer loyalty . the problem has been identified in a number of remarks concerning the extent of awareness that the administration
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The Ant System Algorithm (ASA) is a member of the ant colony algorithms family in swarm intelligence methods (part of the Artificial Intelligence field), which is based on the behavior of ants seeking a path and a source of food in their colonies. The aim of This algorithm is to search for an optimal solution for Combinational Optimization Problems (COP) for which is extremely difficult to find solution using the classical methods like linear and non-linear programming methods.
The Ant System Algorithm was used in the management of water resources field in Iraq, specifically for Haditha dam which is one of the most important dams in Iraq. The target is to find out an efficient management system for
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تقييم قابلية اداء متطلبات العمل للعاملين في الصناعة باستخدام طريقة القصور الذاتي
Background: preparation of root canals is an important step in root canal treatment. Mechanical instrumentation of root canals cause an irregular layer of debris, known as the smear layer. As a result, several studies reported that preferring the removal of the smear layer. Objective: To study the influence of the energy (100 mJ) of Erbium, Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser at short pulse duration (60 μs) on smear layer removal of apical third after using Photon induced photoacoustic streaming technique. Materials and methods: Eighteen straight single-rooted mandibular premolars were used. The roots length were uniform to 14mm from the anatomic apex and
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الجمود المؤسسي واثره في فشل التنمية السياسية : محاولة من اجل بناء مفهوم
Objective: To evaluate the client's satisfaction about the services provided in primary health care centers in the
city of Baghdad and its impact on the improvement of services.
Methodology: A simple random sample consisting of (200) clients to primary health care centers in the city of
Baghdad, (15-20) clients for each center using a questionnaire to evaluate the client's satisfaction for the service
and the use of the direct method of interview, which lasts for (6-10) minutes.
Results: Results of the study show that the number of men visits to primary health care centers, fewer women
This indicates that the most important responsibilities of family members and private health care is the
responsibility of women than
ان مرتكزات السياسة الخارجية العراقية لمرحلة ما بعد العام 2003 قد عكست توجهات ايجابية قادت الى صياغة مجموعة من الرؤى والتصورات الاستراتيجية الجديدة التي افضت الى اعتماد وتوظيف الوسائل والقنوات الدبلوماسية بوصفها وسائل فعالة وبطريقة متكاملة ومتوازنة من اجل تعزيز مستويات الاداء الفعلي وتحقيق جميع الاهداف المستقبلية للسياسة الخارجية العراقية في ضوء صياغة معادلة مفادها: تدعيم وترصين اداء مؤسسات صنع السياسة ال
... Show MoreThe stage of the establishment of the Alawite state in tabaristan was one of the most important stages in the history of the Shiite sect in Iran , from a political , religious and even military point of view ,