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 essential objective of this study presents a analyzes of the combination of reality and fantasy in three dramas of Spanish author Alejandro Casona. "Trees die standing" (premiered in Buenos Aires in 1949), “Prohibited suicide in spring” (premiered in Mexico in 1937) and "The boat without fisherman" (premiered in Buenos Aires in 1945).
The first part is an introduction about the biography of Spanish author Alejandro Casona that will allow us to understand some peculiarities of his work in relation to the social historical context of his time.
In the second part of this study we have analyzed elements of reality and fantasy in the th
... Show Moreدراسة تحليلية لترجمة المسكوكات اللغوية في الصحافة الاسبانية.
ان العقد – في تكوينه – عبارة عن اتفاق ارادتين من اجل احداث اثر قانوني معين ، بيد ان العقد نفسه – في آثاره – يخضع لمجموع الالتزامات التي تشكلت طبقاً لما انصرفت اليه ارادة طرفيه ، فضلاً عمّا تيسّر من احكام اخرى فرضها المشرع او العرف او العدالة او مبادئ حسن النية .
There is no doubt that the narrative form is a mixture of many elements that it
becomes so hard to differentiate between them. Thus, to differentiate between those
elements we must understand the job of every element; and that is the structure of narrative
form in the artistic frame of the old Arabic poem.
Poetry, as the readers confirm, is strongly related to a lot of arts. The rhetorical
form is related to the art of drawing and photography, the rhythm- the core of poetry- is
related to music, its structure to the art of architecture, its tension to drama as it consist of
internal conflict between its elements and ingredients, and the poetry has a narrative
element which relates it to the art of narration and it
نزع السلاح بعد انتهاء الحرب الباردة " دراسة نقدية"
Financial compensation contracts related to Hajj
أسلوب العطف: دراسة مقارنة بين اللغة العربية والاسبانية
This research is a rhetorical study that sheds light on theme
prominent of central identified as custom poet of MUDAFAR AL NAWAB
political and national' that "wine "that themes which had a prominent
presence and intense in his poetry .and objective of this research is to detect
the aesthetic performance ALNAWABY in which he put to categorization
"wine" ,through observation of manifestation the presence of winey. And
related scream the images and the meaning of talking semantics base to
move in the spaces of the text and have built our study on three topics: we
started The first research with lexicon russet in the processes of counting
and analysis of the semantics wine in the office of the poet trying to reveal
התמצית השניות היא התורה שנזכרת כי המוצאים בלשון הערבית וכך בלשונות השמיות אינם הבטויים בעלי האותיות השלושיות , אלא בעלי שתי אותיות . לפי כך אפשר להשיב השורשים השלושיים לשורשים השניים . וכל אות שנאספה בשורש שׁניוני, יהיה לפי חוק ההתפתחות הלשונית , הוספות תחילית , תוכית , סופית , עם השארת החיבור המשמעתית בין השׁניוני והשׁלשׁי כמו היא ממושכת בין השׁלשׁי והרביעי ומה שרבה ההוספות . השרשים השניים מוצאים הם: אות וה
... Show MoreThe importance the youth because they are the fundamental basis of the development process so to be an emphasis on their active participation in community building . When there is community participation the democratization . Will tazzfa community because the process of community participation and develop the capacity to carry on almsoulin among young people and will lead to culture of self confidence and alhawwar walaklauah . Beactivted and community participation for young people through several channels . Family , school , media and civil society organization as we discussed in the research factrstnat hinder community participation of youth in development . The most important factors that hinder participating based on patriarc
... Show More