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 curriculum balancer (comparative) (comparative linguistics), of great
importance in studies of language in general, and study any phenomenon of
acoustic phenomena, morphological, syntactic and semantic study of balance in the
Arabic language in the light of the dialects of the Arabian Peninsula, leading to
significant results in linguistic research, which could achieve Some issues that were
not up to where the old research conclusive results, and helps to explain things may
have created confusion if it did not mean the budget in the interpretation of the
study, as well as its importance in the origination of phenomena of language and
reasoning on the same phenomenon, followed by the Sisters Arab Veseltha.
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The research addresses a pattern of imagery which is regarded a Prominent feature of Abi Tamaam's Poetry (the image of implicit simile) which is based on the hidden signified and the signifier which can be deduced out of context . The investigation requires a study whose proof is based on imagery which is of three types: natural proof , human proof and Quran proof . After handling the realistic structures of this image, the researcher has shifted attention to its types and has dealt with the psychological domain , dividing it in two types: the sensory image and the mental image. The research is directed towards studying the implicit sentence regarding its styles of expression : declarative expression and composition expression . The
... Show MoreEvery era characterizes with its thought and life philosophy , where Muslims left behind them educational and intellectual heritage we should proud of it because it reflects the image of past and lights the way of present and future path where we should make use of it to fit with our statuesque and contemporary issues because we don’t know about it but little as result of ignorance or imitation of the western culture.
It’s wrong to regard heritage from the past but aphasia of Islamic and Arab genies that its roots tracing back to past and extending to future .
Islamic Arab educational thought regards one of the ric
... Show MoreIbn Hajar is one of historian who had a role in historical writing represented by his writings in those active participation in the Arab-Islamic civilization, particularly his approach to intellectual, and pictures of us in his book that's part of the intellectual heritage, but a line that was a key part of the book, any manuscript
السياسة الداخلية لعراق ما بعد الانتخابات 2010 دراسة في الثوابت والمتغيرات
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
The objective of the research is to find the best method to estimate rice crop through out evaluating the applied methods of stratified random sampling .By using different sorts of sampling estimators, a comparison was held among the variances of the mean for simple random sampling, stratified random sampling(var()) and separate regression estimator. The results indicate that the separate regression estimator give best estimations. The approximate cum.f4/5 method was used to determine the optimum stratum boundaries, new strata was put and then var () was calculated .In comparison with strata used nowadays in central statistical organization, the new strata led to obvious decrease in the variance. The stratified mean wa
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تم التطرق إلى مفهومي الخجل والعنف الأسري لدى الفتيات ضعيفات السمع ومشكلة البحث تكمن بدراسة العنف الأسري لضعيفات السمع وعلاقته بالخجل ومعرفة ما يترتب عن ذلك بالنسبة للفتاة المراهقة ضعيفة السمع أثناء تعرضها للمعاملة السيئة وأثره على شخصيتها ، فالخجل هو نتيجة لأساليب التربية الخاطئة التي تعاني منها الفتاة ضعيفة السمع ، ويهدف البحث إلى التعرف على الخجل وعلاقته بالعنف الأسري لدى ضعيفات السمع في محافظة بغداد ، و
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