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.
Abstract
This study dealt with " The Strategic analysis of Operating Income". The study Concerned with two main variables, they are: Strategic analysis and operating income and used one of the total strategic analysis tools, it is "resources analysis method" through analysing the change in operating income in the years that taken in comparing in three components: growth, price recovery and productivity.
To achieve the goal of the research, the study depended upon a hypothesis, "The strategic analysis of operating income leads to supply the appropriate information for the management to make sure of executing its definite strategies".
There is agroup o
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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.
The Arab woman expressed the life of oppression that she suffers from in her masculine environment, as she expressed her linguistic abilities with eloquence and intelligence, as she did not neglect philosophy, wisdom, and exhortation
الحمد لله رب العالمين والصلاة والسلام على سيد المرسلين أبي القاسم محمد (صلى الله عليه وآله وسلم ) وعلى آله الأطهار الميامين ، وصحبه الأبرار المنتجبين إلى يوم الدين 0
وبعد : فإن أجلّ ما بأيدي أبناء هذه الأمة القرآن كتاب ربّها ، الناطق بمصالح دينها ودنياها ، الذي جعله الله تعالى هدىً ورحمةً للعالمين ، وأنزله على خير خلقه من عباده محمّد الصادق الأمين ، وحث المسلمين على أتباعه ، وأمرهم على ل
... Show MorePlay constitutes a significant means for children to figure out the world around. Play helps children to have a healthy brain that increase their creativity via developing emotional, cognitive, physical strength. Thus, the current research aims to identify the role of play in psychological development of children. The findings of study revealed that play develops children’s cognitive, emotional abilities and enhances their self-confidence. Play forms a major approach for learning that promotes children to get rid of stress. Additionally, it supports language development of children
تشكل الاقاليم الانفصالية خطرا يهدد نسيج الدولة
This research aims at studying each of the cold and hot thermal wavelengths affecting
Iraq for a minimum climatic course of 11 years beginning from 1992 till 2002. Three stations
were selected including the parts of Iraq surface: Mosul, Baghdad and Basrah.
The wave days were also connected with the related climatic elements represented by
the wind direction and speeds and the relative humidity. It was shown that Iraq is affected by
the rates of hot thermal wave lengths greatly compared to the rates of cold wavelengths. The
results suggested that the highest rate of hot and cold wavelengths recorded over Basra station
was (3.5) days for the cold and (5) days for the hot. While the lowest rates was at Mosul
station
The research aims to prepare a report by the external auditor (Federal Office of Financial Supervision) for the control environment it is includes financial control, commitment and performance of the North Oil Company (extractive) according to the causes of pollution. The research problem it is not the Federal Office of Financial Supervision preparation a report on the things the environment include the prevent or reduction failure the administration of the causes of the pollution caused by oil mining industry by both bad planning or operational or related to efficient human resources as well as of technology to use and resulting from non-compliance local laws and instructions, as well as the inefficiency of spending on environme
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Recently, the theory of Complex Networks gives a modern insight into a variety of applications in our life. Complex Networks are used to form complex phenomena into graph-based models that include nodes and edges connecting them. This representation can be analyzed by using network metrics such as node degree, clustering coefficient, path length, closeness, betweenness, density, and diameter, to mention a few. The topology of the complex interconnections of power grids is considered one of the challenges that can be faced in terms of understanding and analyzing them. Therefore, some countries use Complex Networks concepts to model their power grid networks. In this work, the Iraqi Power Grid network (IPG) has been modeled, visua
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