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.
Education received the attention of the monarchy in Iraq, especially after the developments that the country witnessed after Iraq gained independence and joined the League of Nations in 1932 AD in all political, economic and cultural aspects. In this regard, due to its distinguished geographical location, where the atmosphere, the natural environment and the religious and political standing were available, which made it a center of attraction for most Iraqi families and political figures. Learning and pioneering the path of knowledge, so it witnessed a great prosperity in secondary education, so several important schools appeared that contributed to advancing the wheel of learning forward, including Baghdad College High Schoo
... Show MoreThis study discussed a biased estimator of the Negative Binomial Regression model known as (Liu Estimator), This estimate was used to reduce variance and overcome the problem Multicollinearity between explanatory variables, Some estimates were used such as Ridge Regression and Maximum Likelihood Estimators, This research aims at the theoretical comparisons between the new estimator (Liu Estimator) and the estimators
أثر استراتيجية التدريس البصري باستخدام الانـفوجرافيك في التحصيل والتفكير البصري لدى طلاب المرحلة المتوسطة فـي مادة الرياضيات
Water resources would be differentiate in Morocco specially in Morocco which appear as form of eyes ,rivers as dissolved water of mountain.
The human takes care of water either as rains to store and use in necessity trying to bring it to Maracas by helping from state .
The religious tried to dig wells to emphasize that water is rumored and do not monopolized.
تلخصت مشکلة هذا البحث في التعرف على الدوافع التي تقف وراء تعرض الطلبة الدارسين في أقسام اللُّغة الإنکليزية للقنوات الفضائية الناطقة باللُّغة الإنکليزية والإشباعات المتحققة عن هذا التعرض في هذا المجتمع الخاص الذي يشکل بيئة اجتماعية علمية محددة، عن طريق تطبيق نظرية الإستخدامات والإشباعات في إطار المجتمعات الخاصة، وسعى هذا البحث إلى تحقيق ثلاثة أهداف هي، قياس استخدامات لطلبة الدارسين في أقسام اللُّغة الإنک
... Show Moreيهدف البحث الى تطبيق تزامن تصميم عملية انتاج معجون الاسنان في مصنع المامون التابع للشركة العامة للمنتوجات الغذائية مع نظام تكاليف الجودة المطبق في الشركة لتحقيق الميزة التنافسية. وتمثلت مشكلة البحث في أن الشركة عينة البحث لا تستخدم نظام تكاليف الجودة بالتزامن مع تصميم عملية إنتاج هذا المنتج لاغراض تحقيق الميزة التنافسية حيث تواجه منتجات الشركة منافسة عالية في الاسواق المحلية. إن الشركة تطبق نظام تكاليف الج
... Show MoreEducation received the attention of the monarchy in Iraq, especially after the developments that the country witnessed after Iraq gained independence and joined the League of Nations in 1932 AD in all political, economic and cultural aspects. In this regard, due to its distinguished geographical location, where the atmosphere, the natural environment and the religious and political standing were available, which made it a center of attraction for most Iraqi families and political figures.
Five mixed primary schools from the district of Tikrit/ Salah al- din province
with a total of 100 male and female pupils and two ages(8-9 and 10-11 years),
were selected randomly to study the relationship between the breakfast meal and
the academic level, the socioeconomic situation, and the number of family
members. The study showed a positive linear correlation between the morning
meal, and academic level of students for both two covered ages, also showed a
clear impact between the development of family's socioeconomic situation and
their nutrition level. There were an increase in the percentage of pupils aged 8-9
years with a poor nutrition when they were belonged to a poor or medium
socioeconomic families,
The writer of this messagewas Tajaddin Ahmad Abdulqader bin Maktoom Al-Qaisy Al-masry.
This message dealt with the biographies of twenty scientists of readers about Quran readings in Cairo . He comprehended these biographies and make it an appendage