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.
Review of the research and the reality of the costs of the survey and exploration in the oil exploration company The study showed the effect of the application of standard financial reporting (6) "mineral resources exploration and evaluation" on the financial statements, have touched on a range of problems, the most important deficiencies in the disclosure of information relating to expenses of research and exploration that must be show Kmugod and which should be recognized as an expense in the financial statements of the company based on the international standard (6) for the purpose of knowing the financial situation of the company, and to find solutions presented researcher hypothesis is the following: that the Company's application s
... Show MoreThe aim of the research is to use methods based on cost-based activities )ABC) to identify the activities that cause the costs resulting from the environmental impact of the gas filling company and then to manage on the basis of the activities to manage the costs of these activities, which in turn rationalizes the environmental costs by eliminating activities that do not add .The research a number of conclusions, the most important of which is that the management of the company should continuously seek to train and qualify its staff on the accounting systems, especially in the field of accounting of environmental costs, the high environmental costs by the company, bears as a result of its activity.
In this paper, a compact multiband printed dipole antenna is presented as a candidate for use in wireless communication applications. The proposed fractal antenna design is based on the second level tent transformation. The space-filling property of this fractal geometry permits producing longer lengths in a more compact size. Theoretical performance of this antenna has been calculated using the commercially available software IE3D from Zeland Software Inc. This electromagnetic simulator is based on the method of moments (MoM). The proposed dipole antenna has been found to possess a considerable size reduction compared with the conventional printed or wire dipole antenna designed at the same design frequency and using the same substrate
... Show Moreدور الذكاء الصناعي في تحقيق رضا الزبون وانعكاسه على محاسبة التكاليف بحث تطبيقي في شركة الصناعات الالكترونية
The great challenge that will face the management in the developed and developing countries at the same time as core issue is represented in the question of the labor productivity in the field of in the Training Of human which is believed that it will prevail upon the jobs of their organization for many coming decades in in next years. Farther more, it will limit the construction of the communities and the quality of this life. Therefore, the priority of the economics of those countries will be headed toward increasing this productivity and giving it tried finally to control economically and managerially. In the light of information era, every organization should become knowledgeable enterprise. And for this reason, the achievement of su
... Show MoreA simple setup of random number generator is proposed. The random number generation is based on the shot-noise fluctuations in a p-i-n photodiode. These fluctuations that are defined as shot noise are based on a stationary random process whose statistical properties reflect Poisson statistics associated with photon streams. It has its origin in the quantum nature of light and it is related to vacuum fluctuations. Two photodiodes were used and their shot noise fluctuations were subtracted. The difference was applied to a comparator to obtain the random sequence.
The rise of edge-cloud continuum computing is a result of the growing significance of edge computing, which has become a complementary or substitute option for traditional cloud services. The convergence of networking and computers presents a notable challenge due to their distinct historical development. Task scheduling is a major challenge in the context of edge-cloud continuum computing. The selection of the execution location of tasks, is crucial in meeting the quality-of-service (QoS) requirements of applications. An efficient scheduling strategy for distributing workloads among virtual machines in the edge-cloud continuum data center is mandatory to ensure the fulfilment of QoS requirements for both customer and service provider. E
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