In this work, the effect of vortex shedding on the solar collector performance of the parabolic trough solar collector (PTSC) was estimated experimentally. The effect of structure oscillations due to wind vortex shedding on solar collector performance degradation was estimated. The performance of PTSC is evaluated by using the useful heat gain and the thermal instantaneous efficiency. Experimental work to simulate the vortex shedding excitation was done. The useful heat gain and the thermal efficiency of the parabolic trough collector were calculated from experimental measurements with and without vortex loading. The prototype of the collector was fabricated for this purpose. The effect of vortex shedding at different operation condition

Limited importance of research in a stand on the most important difficulties faced by both faculty and parents to communicate with each process to follow up on their children, and the analysis and inventory of the obstacles that hinder the educational process, and work to develop a vision of how to address these constraints and the important role of technology in the treatment of problems of the society so as to develop frameworks future to minimize the errors and the problems they face, and the development outlook for future generations in order to promote the educational level, especially that Iraq is going through a change in conditions in all sectors. Through the questionnaire, which includes questions set that was made on a sample o

The povety in a subjct of one of the most important problems that
accompanied the development process in iraq and is now pointing in the
depth of institutional struetues and threaten the sociol fabric and cohesion
mechamisms .
The study included of the most importana social problems that
accompamied thecrises and occupation in iraq as aproblem of unemployment
aworce, forced displacement and disintegration of family and juvenile
delinguency and the problems of drug addiction .
The study relied on sample slected from the city of Baghdad ,showed
the most important results of that two-thirds of the asssets of an urban sample
compared to one third of them from rural aelcyrounds and that there is
arelationship

The study highlights the rivalry of foreign interests in Iraq, especially after the establishment of the monarchy in 1921. This period was characterized by extensive American activity in Iraq in general and Baghdad in particular. This activity increased after the Americans obtained the concession which came in the light of Article IV of the 1930 Treaty. Which officially guaranteed US interests in Iraq. The research also discussed the efforts of the Jesuit Fathers in Baghdad to convert the Church of Wisdom from a place of worship and rites of the Christian religion to a school of the propagation of science and culture along the lines of American schools, College Baghdad), which has become an important school in Baghd

The legal text in the language of civil law, constitutional law, language of judges, and legal profession is concerned with a legal language and words that are coherently significant

The proliferation of electronic games, video games and computers has caused children and teenagers to become attracted to these games and become their favorite entertainment. The widespread of these games has generated widespread debate about positive aspects and negative aspects. It is evident that there are two main trends in the impact of electronic games on the behavior of children and adolescents. The first trend is that e-games have positive effects on children and adolescents, especially in cognitive abilities and skills in learning. While the second view sees that electronic games have negative effects that appear in social isolation and lack of movement and aggression. Through the review of previous literature, the current resea

تم ت داول مصطلح الأزمة ا دلولية في السياسية ا دلولية خال القرن التاسع عش ر لتحدي دا ملدة الانتقالية بين السلم والحرب سواء أ دت الأزمة إلى نشوب صراع مسلح أم مت ت ت سويتها بالطرق السلمية، وتع دالأزمة ا دلولية مرحلة مت هيدية ل لحرب وهي ا رملحلة التي يسعى فيها أ طرا فالأزمة إلى إبعاد احتمالية نشوء أ و اندلاع الحرب، فالأزمة ه ي مدة حرجة ومرحلة خطيرة بين وقتي السلم والحرب، إن العلاقات ا دلولية تكاد ت عيشأ زمات متلاحقة ع

The study of the future of the international system currently appears, according to scientific data and existing facts in light of the emergence of international actors from non-states and international informal institutions, to be heading towards a non-polarity system and this trend is fueled by many variables to reduce polarity, and it is expected in the future that the international system will turn into a non-polarity.

Abstract The Kenyan policy towards Somalia was influenced by a set of interrelated factors between the two countries and stemmed from the internal environment and most prominent: the geographical factor, ethnic, cultural, religious, political, economic and security, has been dominated by this policy since independence from the British colonial administration in the sixties of the last century and so far the nature of instability and tension, As the two countries are geographically contiguous and as security risks escalate, Kenya in 2011 rushed military action against Somalia, the first military action by Kenya outside its borders since independence.

اهمية البحث والحاجة اليه :

            في بداية ظهور التلفزيون كانت البرامج المقدمة تعتمد على المنوعات والمسرحيات المنقولة من المسرح . وقد استفاد التلفزيون من الفنون التي سبقته مثل المسرح فنرى ان :

" محطات التلفزيون بادرت بتسجيل المسرحيات المتعددة لتملأ بها ساعات الارسال " [1]

            وكذلك