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.
Praise be to God, Lord of the worlds, and peace and blessings be upon our master Muhammad, and upon his family and companions as a whole. Now, the research deals with the grammatical issues mentioned in the Book of Al-Zahir in the meanings of people's words to Abu Bakr Al-Anbari (d. 328 AH). Two parts of the book have more than one edition, it was printed by the Iraqi Ministry of Culture and Information Beirut in 1979 AD, and the Al-Resala Foundation issued the second edition in 1992 AD The third edition was printed in Dar Al-Bashaer in Damascus in the year 2003 AD and it was the reliance on the research and the grammatical issues were arranged on topics that are: interrogation - Deletion, exclusion, marbling, call and Wallace Relief and
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The study aims to know the degree of secondary school managers' practice of servant leadership in Gaza from their teachers’ perspective. It further aims to examine whether there are any statistically significant differences at (α 0.05≥) between the means of the study sample’s members attributed to variables such as (gender, educational qualification, and years of experience). To achieve the objectives of the study, the study adopted the descriptive survey method, using a questionnaire consisting of (30) items distributed to four domains: (workers service, ethical dealing, motivation & influence, and building an organized, integrated society). Then, the questionnaire was distributed to t
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In this work an enzyme linked immunosorbent assay (ELISA) technique has been used for detection of some inflammatory markers in serum of acute coronary syndrome (ACS)-Patients Admitted to the cardiac care unit (CCU) of Iraqi Centre For Heart Diseases and Ibn AlNafees Teaching Hospital. The present method includes quantitative measurement of interleukine-6 (IL-6) and C-reactive protein (CRP), as their increase during symptoms may be responsible for identifying the mechanism of myocardial damag, in addition to their best performance than other quantitative tests perhaps due to their association with atherosclerotic process that belongs to the endothelial dysfunction. Aim of this study is to estimate the prevalence and correlation of IL-6 w
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In this research we study a variance component model, Which is the one of the most important models widely used in the analysis of the data, this model is one type of a multilevel models, and it is considered as linear models , there are three types of linear variance component models ,Fixed effect of linear variance component model, Random effect of linear variance component model and Mixed effect of linear variance component model . In this paper we will examine the model of mixed effect of linear variance component model with one –way random effect ,and the mixed model is a mixture of fixed effect and random effect in the same model, where it contains the parameter (μ) and treatment effect (τi ) which has
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The present study discusses the semantic characteristics of the Russian newspapers journalistic headlines (The Russian newspaper "Komsomolskaya Pravda" as Example"). The study traces the characteristics of the Russian newspaper headlines, its relevance to grammar, syntax, lexical items and style. These characteristics in Russian will be investigated and compared to their Arabic correspondents in the process of translation. The study also specifies the meanings and the functions of the newspaper headlines in the light of modern linguistics stressing the grammatical, lexical and stylistic aspects of headlines translation from Russian into Arabic.
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The goal of current research is marked "student services for the university student at the Faculty of Education for Girls at Baghdad University in light of the overall quality indicators)" to identify the relative importance of the availability of student services offered by the College of Education at the University of Baghdad, from the viewpoint of the students. The research was Aaguetdy followers researcher Find descriptive approach to suitability research topic and in order to achieve the purposes of research, the researcher designed questionnaire examined consisted of (18) items and has been questionnaire on arbitrators and experts to verify the validity and reliability that's been applied to the questionnaire on a group of students
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The research explain the analysis of finance investments through analyze the finance tables for commercial banks, by using the pointers to indicate the limits of economical benefit for these investments, and fix the negative deviations and as well positive, for the purpose of diagnostic the negative (disadvantage) and develop the advantage deviation, For the importance of finance investments in the development operation and economical growth, further to that the finance investments is represent one of the most activities in the commercial banks in which aim the adequate incomes as a result of the commercial banks act to receipt the banks deposits and then make it growth and develop through commercial advantage o
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