The design, construction and investigation of experimental study of two compound parabolic concentrators (CPCs) with tubular absorber have been presented. The performance of CPCs have been evaluated by using outdoor experimental measurements including the instantaneous thermal efficiency. The two CPCs are tested instantly by holding them on a common structure. Many tests are conducted in the present work by truncating one of them in three different levels. For each truncation the acceptance half angle (θc) was changed. Geometrically, the acceptance half angle for standard CPC is (26o). For the truncation levels for the other CPC 1, 2 and 3 the acceptance half angle were 20o, 26o and 59o, consequently. A significant difference between the instantaneous thermal efficiency of 3.86× CPC (θc=20o) and 2.32× CPC (θc=26o), and between that for 3.61× CPC (θc=26o) and 2.32× CPC (θc=26o). It's noticed that the difference between the instantaneous thermal efficiency of 2.32× CPC (θc=59o) and 2.32× CPC (θc=26o) is small compared with the difference of the first and second cases, the instantaneous thermal efficiency of 2.32× CPC (26o) was higher than those for other three CPCs. The experimental results show that the maximum thermal efficiency of the full 2.32×CPC (26o) is 0.708, the maximum thermal efficiency of the 3.93×CPC (15o), when it's truncated to 3.84× CPC (20o), 3.61× CPC (26o) and 2.32× CPC (59o) are 0.51, 0.52 and 0.66, respectively. As the concentration ratio decreases from (3.93× to 1×), the thermal efficiency, energy losses and optical efficiency increase from (0.47 to 63), (1.58 to 7.2 K.m2/W) and (0.494 to 0.797), respectively.
the boot of honesty in the dictionary the term linguistic and religious
heritage, literary and Islamic Sufi thought, and concept in the literature of Imam
Ali, peace is upon him. And studied the summary first concerns its presence in the
literature and implications and directions, either the second part, has cared for the
analytical study has found research that safe weight was the counterpart of the
personality of the Imam accompanied the character most prominent in his
character, namely, (courage), it has struggled to deliver a impact of humanity in his
time and after the word and deed, It was based on the imagination in the formation
of images sensual and intellectual, to his persuasion of the evidence and argu
It is summarized that Abu-Baker Al-Soly is one of Arabic Muslim scientists who had special style in literary writing specifically in sciences and knowledge that had depended on the encyclopedia culture gained from various fields of science , this means that he was an individual who had participated to characterize features of Islamic –Arabic history enhanced the rules of it , this matter would encourage us to know the method and style of writing in the field of intellectual life in which the writer depended on the procedures direction of scientists that he lived in the Abbasid era .
يعد التأمين أحد المؤسسات المالية ذات التأثير على برامج التنمية ، وما زال قطاع التأمين يعاني من العديد من المشاكل منها الوعي أو التشريع أو كيفية توظيفه كمورد اقتصادي واجتماعي خدمة للمجتمع والمؤسسات والافراد. وحيث أن التأمين يقدم خدمة تستوجب التزامها بمواصفات محددة ، لذا أصبح من الضروري دراسة آليات تحسين جودة الخدمة التأمينية وكذلك دراسة واقع العملية التسويقية للخدمة التأمينية وما ينالها من تحديات داخلية أ
... Show Moreالسياسة الداخلية لعراق ما بعد الانتخابات 2010 دراسة في الثوابت والمتغيرات
Quran orders and commandments and principles, has avenged children, their status and dearest, and saved their lives, which reached ill before Islam, and filled the hearts of the fathers and mothers for their love, but to make them embellish life.
Cette recherche étudie les structures composant Barbara, un poème de Jacques Prévert pour mettre en valeur la particularité de ce langage. Nous avons d'abord, dissocié ces structures, en : structure thématique, actancielle, syntaxico-énonciative, sémantique, formelle et finalement spacio-temporelle en vue de les analyser minutieusement. Le poète a adopté pour les thèmes : souvenir, nostalgie et guerre, un langage simple et une syntaxe incomplexe. L'usage du lexique et des figures de style célèbrent ces thèmes. La forme, la versification et la sonorité approfondissent ces images et renforcent ce langage. Ce poème dépend des phrases simples et variées : affirmative, interrogative, exclamative qui s'orientent vers des acte
... Show MoreThis study is a complementary one to an extended series of research work that aims to produce a thermodynamiclly stable asphalt –sulfur blend. Asphalt was physically modified wiht different percentages of asphaltenes , oxidized asphaltenes and then mixed with sulfur as an attempt to obtaine a stable compatible asphalt-sulfur blend. The homogeneneity of asphalt-asphaltenes[oxidized asphaltenes]-sulfur blends were studied microscopically and the results are prsented as photomicrographs. Generally more stable and compatible asphalt-sulfur blends were obtained by this treatment.
The central nervous system is the most important system and is very sensitive to any accidental infection during ontogenesis; it includes brain and spinal cord. The cerebellum is the second largest part of the brain after cerebrum and it’s very sensitive to the abnormal changes during the embryological development. This study was designed to investigate the effect of the maternal exposure of selected concentrations of suspension of nanoparticles on the ontogenesis of the rat cerebellum after embryos implanted in uterus. A total of 60 female pregnant rats were divided in to three groups, each contains 20 females. Group1 (G1) was treated orally with 2mg/kg /body weight (b. wt) of suspension of silver nanoparticles (Ag NPs). While group 2 (G
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Reflect the sustainable development of the interaction of three key elements are the economic component and the social component and the environmental component while focusing economic component to achieve economic growth and focuses social element to achieve social justice in the distribution of income and achieve prosperity, the environmental component related fields and including emphasizes the protection of the environment and to ensure the continuation and sustainability of resources physical, biological and form in which it believes the interaction required for development process real and effective and sustainable, and is considered the province of Kurdistan Iraq of important areas where the movement of developmental mount
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