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.
عرفت النظم القانونية انواعا مختلفة من الشركات اذ تعتبر الشركة الوعاء القانوني الاكثر ملائمة لغرض توظيف اموال المستثمرين في مشاريع ذات اهمية والذي يحقق نفا لاصحاب رؤوس الاموال المستثمرة فضلا عن اثرها البالغ على اقتصاد الدول وقد كان للشركة القابضة نصيب من هذا الاهتمام منذ القدم لدى العديد من الدول ووضعت لها احكاما تفصيلية تتناسب مع الاهمية التي يحظى بها هذا النوع من الشركات كونها تجمع لعدة شركات فرعية تسيطر ع
... Show MoreThe main target of this research is to follow the stages of the emergence of
the idea of republican form of government from its very beginning , yet there
were many elements from different estates thinker , educated , few of heads of
clans . This first opportunity for the mobilization of politically-minded people
with fundamental activity like najei shokat . hussain al-rahal notable poet maruf
al-rasafi those who formed what so called the political elite who believed in
constitutional , democratic parliamentary republic , one of them was al-rahal who
called for a constitutional republic even before the emergence of the
constitutional movement in Iran and ottoman empire (1908).
The holy najaf become cultural cen
اسلوب الحوار في القرآن الكريم اسلوب حياة وفي حقيقة الامر يضم القرآن الكريم بين دفتيه حوارات كثير مابين الله عزوجل وخلقه وما بين الانبياء واقوامهم وما بين الانبياء والطواغيت ومابين المؤمنين والكفار وهكذا ، وبدء الخلق قام على حوار مابين الله عزوجل وآدم وما بين آدم وابليس وما بيا الله جل وعلا والملائكة .
لم تعد اللغة مجرد أداة للتعبير عما يفكر به المتكلمون، إذ تعدت ذلك إلى أن تكون سبيلاً في صناعة العالم على وفق مقاربة تداولية، وقف عليها علماء البحث اللساني من أمثال أوستن و هرسل، للكشف عما وراء اللغة، وما يقصده المتكلمون، والبحث عن أفعال الكلام التي يسعى المتحدثون الى استعمالها، ولذلك اتجهت هذه الدراسة للوقوف على شعر عصر صدر الإسلام، واجراء دراسة تداولية لاستكشاف الأفعال التي كثيرا ما استعملها شعراء الإسلام
... Show MoreThe concept of poetics has different dimensions, part of which is related to the creative achievement, and part is related to the critical perspective.
Among the commentators who contributed greatly to explaining the basic rules of civilizations in general and Islamic civilization in particular, Sheikh Muhammad Rashid Rida in his interpretation called (Interpretation of the Wise Qur’an), known as (Al-Manar); Whoever reads the tafsir will notice that it was concerned with explaining the civilized aspects in terms of foundations, methodology, factors of demolition and destruction, and ways to avoid them.
This research attempts to study Monetary system status and financing in the CIB through 4 sections, starting with the methodology and ending with conclusions and recommendations.
These two topics of Monetary and financing, that falls within the mandate of the CBI, are researched / studied relying on the resources and relevant literature. This research is a simple contribution, but meantime it is an honest attempt to elevate the effective role of the CBI which is considered one of the most pioneering central banks in the region.
على وفق ستراتيجية توظيف الامكانيات الاسلوبية والفنية والجمالية للحوار بنوعيه( الحوار الداخلي ) و( الحوار الخارجي ) استطاعت الكاتبة ان تمنح روايتها ( ذاكرة الجسد ) خصوصيتها الادبية .فعلى مستوى الوظيفة البنائية اسهم الحوار في التشكيل الزمني لبناء الرواية ،وتقديم الشخصية ،وبناء الحدث وتطويره .وعلى المستوى الاسلوبي نجد أن الحوار تجاوز وظيفته الاخبارية الى وظيفة التأثير في المتلقي من خلال الافادة من معطيات المسر
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