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.
تهدف هذه الدراسة إلى استقصاء العلاقة الديناميكية بين التحولات السياسية والحراك الشعبي وتأثيرهما في تجسيد الزيارة الأربعينية في العراق، من خلال تحليل تطورها الرمزي وتفاعلها مع سياسات الحكومات العراقية المتعاقبة منذ تأسيسها عام 1921 وحتى مرحلة ما بعد 2003. تُفصل الدراسة كيفية تعامل السلطات العراقية المتعاقبة مع الزيارة الأربعينية، مع تسليط الضوء على اعتبار الزيارة منبراً للتعبير عن الحراك الشعبي والرفض للإجرا
... Show Moreالنحت العربي في جنوب شبه الجزيرة العربية (اليمن) قبل الاسلام
The research studies the semantic generation structures of
commodity names in the Baghdad dialect of Arabic, specifically
those names that reflect popular taste. Through descriptive field
studies of the social use of these words
يعد التحليل العاملي Factor Analysis أحد الأساليب الإحصائية المهمة والتي يصعب تنفيذها يدويا ً أو بالألات الحاسبة الصغيرة لذا لاقى الباحثين صعوبة في إستخدامه في البداية بل كان من المستحيل القيام به ، لذا فالمؤلف قد تناول التحيلي العاملي الاستكشافي لكونه إسلوب إحصائي يستخدم في تحليل البيانات ويتطلب شروطا ً لأستخدامه ودقة في مراعاة هذه الشروط ويتطلب أيضا ً معايير يجب أن يتأكد الباحث من توافرها في البيانات وهذا ما تم ت
... Show Moreالغلط في القانون الانجليزي على انواع ثلاثة (غلط مشترك Common mistake ) يقع فيه الطرفان مع علم كل منهما بنية الآخر ويقبلها دون ان يشوب الاتفاق نقص او يعتريه تحفظ ، و(غلط من الجانبين Mutual mistake) يكون كل متعاقد واقعا في غلط فيما يتعلق بما قصده الآخر، فيقدم كل منهما عرضاً مخالفاً للآخر و(غلط من جانب واحدUnliteral mistake ) يقع فيه احد المتعاقدين فقط ويكون المتعاقد الآخر اما عالماً بالغلط او يفترض انه عالم به . فإذا دفع احد المتعاقدين
... Show MoreThe phenomenon of multi-class construction and landlords has increased in Iraq, and this is not justified except because of the change in the economic and social conditions in it, because like any social system interacts with what happens in society, whether it is positive or negative, and since the vertical housing system contains common parts and these parts need to Maintenance and preservation, and in order to continue to perform the construction and other parts in an effective and regular manner for a long period of time and with appropriate efficiency, it must be maintained, and maintenance is one of the most important and difficult problems facing the partners. It is recognized that it is not possible to understand these practical dif
... Show Moreهدف البحث معرفة نسبة تضمين معايير التنور التقني في محتوى كتابي الحاسوب للمرحلة الإعدادية في العراق عن طريق الإجابة عن السؤال الآتي: ما نسبة توافر معايير التنور التقني في محتوى كتابي الحاسوب المقرران على طلبة المرحلة الاعدادية بفرعيها ( العلمي والادبي ) المعتمدان من وزارة التربية العراقية/ المديرية العامة للمناهج في العام الدراسي (2016-2017 )؟ وتم اعتماد المنهج الوصفي التحليلي، وتكون مجتمع البحث وعينته من محتو
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Language is a gift from God to His servants, as it is a tool of communication, rather it is a tool of life, and without it, life cannot be straight and complete.
A language is a kind of substitution. A vocal disorder that may be a disease of speech, and it is one of the obstacles caused by organic and congenital causes, perhaps the common one is genetic.If we separate between lisping in children and separating it from what happens in adults, we find that lisping in children may have psychological causes as well as other ones, this is what we will show in this research.
It was the sayings of Andalusia scholars in agriculture based on experiments and theories that helped a lot in the success and development of agriculture in the Andalusia ,and also The divisions of the soil and out types and forms it helped a lot of to know arable of non-arable land earth and all off the determination of the color of repentance is important often discovered by agricultural scientists and that helped in the cultivation of certain crops in certain land without another land.and though each particular agricultural crops specific soil in which to live and not live in other soil ,
Abstract
The Holy Quran is the greatest motivator for the mind to keep pace with life. The doctrine of faith is a requirement of logic and wisdom, and it cannot be reached by the hand of superstition. The Qur’an destroyed the principle of superstition in the verses of the creation of the universe. The principle of inactivity of the Qur’an is a false accusation that collision with the texts of the Qur’an. The secret of scientific development is to harness the laws of nature, benefit from them, and walk according to its requirements, on which the manifestations of civilization and the Qur’an are based
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