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.
We have found through research , that administrative institutions on the outskirts of Kufa and their management is not as important as administrative institution in place that were associated with it and subject to its control ,as it often was express power , or poor ( if true ) expression , directors of the center for the suburbs , as it became clear to our diversity of those administrative institutions and prominent role in the interest of the affairs of the people and society in all aspects of life , and are the functions and different staff from the highest authority the suburbs represented by house of representatives ( the workers ) ,then workers abscess and Al-dhaqan and not to mention for other jobs came the actions of Bhaltsier a
... Show MoreLinear and nonlinear optical properties of epoxy/ Al2O3 nanocomposites system were studied for epoxy neat and (0.5, 1.5, 3, and 5) % Al2O3 nanocomposites.The band gap of epoxy and its nanocomposites was obtained at these weight ratios. Nonlinear optical properties experiments were performed using Q-switched Nd:YAG laser z-scan system.These experiments were carried out for different parameters: wavelengths (1064 nm and 532 nm), laser intensities (0.530, 0.679, and 0.772) GW/cm2 and weight ratio of Al2O3 nanocomposites. The results showed that the band gaps were decreased with increasing the weight ratio of nanoalumina except at 5wt% and the nonlinear refractive index coefficient is directly proportional to the incident intensities while o
... Show MoreThe aim of this work is to study the effect of mud compositions on it’s rheological behavior under high temperature conditions. Seventeen samples of five types of water base mud in which (fresh water bentonite mud. Lignosulphonate mud, gypsum mud, polymer mud, and salt saturated mud) were tested with different temperatures using the fann viscometer model 50-c. All the tested samples, except the fresh water bentonite mud, have the same trend reduction in both plastic viscosity and yield point with increasing temperature. Six rheological models has been adapted: Bingham plastic, power law, Casson model represent the laboratory data accurately
The paper tries to explore the grammatical phenomenon of rankshift in Systemic Grammar, a functional grammar that establishes five units or the rank scale , : namely sentence, clause phrase, word and morpheme .Rankshift a Hallidayan term , occurs when a given unit is downgraded or shifted down the rank scale and operates further down its rank or a rank equal to itself as when a clause which has to operate in sentence structure operates at q “ qualifier” in a nominal group. The paper , quite significantly, introduces the systemic background that enunciates the systemic theory whose organising concept system rather than structure. The paper then, grammatically explores rankshifted elements, successive rankshifting, degrees of rankshifting
... Show MoreEmbedded advertisement constitutes a special kind of communication. As it performs many important roles such as giving information, highlighting the value of the product, and urging the target consumer to buy it by influencing his/ her behavior using an attractive manner of mind and conscience. Both cinema and television are the most prominent and powerful advertising media that enjoy the interest of all audiences and capture most of the advertising spending. As advertisers have paid attention to the importance of indirectly incorporating their products into content that the audience loves and is keen to follow, since the actual impact lies in the inclusion of the product within content that the audience appeals to. Hence, this leads to
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The Present study aims to shed some light on the concept of authority of university students and to find statistically significant differences as regards this concepts in accordance with three variables gender (males, females),field of study(scientific ,humanities)and grade(second ,fourth). To accomplish the study a ( 7) level scale was developed for the concept of authority and it subjected to validity and credibility the scale was used with 590 student sample (237) males and (353) females Results show that male students show obedience to authority forms below the Avery e component with the theoretical Avery of the scale besides ,reinforcement was on the top of authority chain ,followed by person traits ,friends, affect punishment and t
... Show MorePraise be to Allah, Lord of the Worlds, and peace and blessings be upon our master Muhammad and his good and pure family. At the end of this research, we summarize some of the most important findings of our research, namely:
Raising a child properly from childhood leads to integrity in the life of the individual society, and if the young raised bad education, this education will affect itself and society negatively, so on parents and government institutions in any country to take care of children, and Islamic countries Specifically to give the child great attention; he is raised on the Koran and watered from its fountains, and armed with a weapon of morality from a young age, and to understand the biography of Mustafa (peace be upon h
In order to reduce the losses due to evaporation in the stored crude oil and minimizing the decrease in °API many affecting parameters were studied (i.e. Different storage system, namely batch system with different types of storage tanks under different temperatures and:or different pressures). Continuous circulation storage system was also studied. It was found that increasing pressure of the inert gas from 1 bar to 8 bar over the surface of the crude oil will decrease the percentage losses due to evaporation by (0.016%) and decrease the change of °API by (0.9) during 96 hours storage time. Similarly using covering by surfactant (potassium oleate) or using polymer (polyurethane foam) decreases the percentage evaporation losses compare
... Show MoreThis study aims to discuss the projects of poultry in Wasit province in 2013 and geographical distribution according to the type and contrast on the level of administrative units representing Districts and The reasons for this discrepancy, as well as knowledge of the factors affecting the distribution by the analysis and reasoning and description This study divided to the four themes, The first of the statement of nutritional importance and economic Poultry focused on the importance of various poultry products, The second one shows the relative position of the province of Wasit between the provinces of Iraq in poultry and production of eggs and meat farming projects, and then followed by the third one (theme) as it ensures the geographic
... Show MoreThis research deals with the formalities of the mortgage contract according to American law, We have given an overview of the provisions of this law related to the subject, We have also taken into consideration the role of American jurisprudence and the judiciary in finding legal solutions to the aforementioned formality, We have discussed the formality of mortgage in American law in two sections, In the first section we showed the formalism in immovable mortgage, and the second section specified to studying the formalism in movable mortgage.