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 Purpose: The determination of standard scores and levels for some mental skills by researchers is of great importance, especially if it matches the target research sample, Method: as the researchers used the descriptive approach in the survey method, and the researchers chose the sample of youth players for clubs for the season (2022-2021), numbering (127) players, and the researchers identified the scale and procedures and applied it to the research sample, Results: obtained the results that were processed, extracted grades and standard levels, and then interpreted them and obtained conclusions, Conclusion: the most important of which are: The standard levels of mental skills reached the results of the sample studied within the
... Show MoreTin dioxide doped silver oxide thin films with different x content (0, 0.03, 0.05, 0.07) have been prepared by pulse laser deposition technique (PLD) at room temperatures (RT). The effect of doping concentration on the structural and electrical properties of the films were studied. Atomic Force Measurement (AFM) measurements found that the average value of grain size for all films at RT decrease with increasing of AgO content. While an average roughness values increase with increasing x content. The electrical properties of these films were studied with different x content. The D.C conductivity for all films increases with increasing x content. Also, it found that activation energies decrease with increasing of AgO content for all films.
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Big developments in technology have led to upset the balance of ideas, given of its own post new properties for products not provided by traditional technology, especially economic units operating within the industrial sector, and therefore it is important to develop the Iraqi industrial sector and interest to do its vital role in light Of progress technological, and the cost accounting has benefited from this technology to development its goals in the regulatory process through the use of non-destructive evaluation perspective in carrying out its functions and to provide appropriate assistance for the use of the products, which were traditional accounting does not take them into consideration. The research aims to a statement that the u
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The research aims to identify the most important areas of voluntary work available to women in society, stand on the most important controls that push women to work in voluntary areas in society. The research also seeks to stand on the most prominent obstacles to the voluntary work of women in society. The research contained four main chapters: Chapter I: Definition of research, Chapter 2: Objectives, areas, controls and effects of volunteer work, Chapter 3: Voluntary Work of Women in the Celestial Religions, and lastly, Chapter 4: Theories, Constraints, and Recommendations for Voluntary Work for Women.The researcher suggested several recommendations: 1-establishing a unit responsible for planning,
... Show MoreBackground: Most prevalent chronic liver disease in developed and developing nations is non-alcoholic fatty liver disease. From fatty liver, which often has benign, non-progressive clinical history, to non-alcoholic steatohepatitis, a more serious variant of fatty liver that can lead to cirrhosis and end-stage liver disease, non-alcoholic fatty liver disease encompasses broad spectrum of diseases. The gold standard for determining extent of hepatic fibrosis is still liver biopsy; however, number of noninvasive tests have been established to make diagnosis and assess effectiveness of treatment.
Objective: Aim of study was to assess effectiveness of the combination of fibroscan and
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The study aims to identify the theoretical literature for all the variables of the study (ICT, GDP) as well as to identify the practical side of the impact of ICT on the per capita GDP in Iraq for the period (2004-2021). The study was based on the hypothesis that ICT impacts per capita GDP in Iraq. The problem of the study was to answer the question: does ICT contribute to per capita GDP? The study concluded that an increase in the rate of internet users per 100 people by one unit would increase. Increasing the landline telephone rate per 100 people by one unit will increase GDP per capita. In addition, increasing the mobile phone rate per 100 people by one unit will increase GDP per capita. The study recommended adopting rational poli
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The steady consumption of fish led many researchers to study it preferences over other foods, especially for radioactivity content. The specific activity concentration (S.A) of natural occurring radioactive materials (NORM) have been measured for Cyprinus carpio fishes collected from several industrial fishes' lakes located in Baghdad governorate using gamma spectroscopy doped with high purity germanium coaxial detector (HPGe). Thirteen fishes' samples were collected from industrial lakes, three samples were collected from cages, and two samples were collected from Trigger River. The last two types of samples were collected in order to compare the results with it. The measured overall averages of S.A for Ra-226, Th-232, and K-40 were 58.
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Abstract
The current research aims to construct a scale for the nine types of students’ personality according to Rob Fitzel model. To do this, (162) items were formed that present the nine types of personality with (18) items for each type. To test the validity of the scale, a sample of (584) students of Al-Mustansrya University were chosen. The data of their responses was analyzed by using factor analysis. The findings explored (9) factors as one factor for each type of personality with (12) items for each one. Then, the reliability of the scale was found by using the test-retest method and Alfa Cronbach method.