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.
the Reception and the Creative Reaction
I often read in Islamic jurisprudence in all chapters as much as possible from divine success, time and health, and everything I read in any of the chapters of jurisprudence, I see divine light, eternal wisdom, and a constitution that does not accept error and alteration, as I looked at the great jurisprudential treasures and this enormous wealth, A person finds in himself helplessness in front of this law, how clear, easy, and accurate it is, and it contains permanent good for man, as it is a religion of mercy, benevolence, and goodness, and among these chapters of jurisprudence is the jurisprudence of the commandment. Of the reasons, in the will, the person has had the opportunity to make up for what he missed of doing good that a pers
... Show MoreThe method of Similarity of important topics in Arabic Rhetoric has ample evidence in the Qur'an and the Hadith and the words of the Arabs and this study is limited to only the Koran.
There have been Similarity in the Holy Quran on both types : investigative and discretion , but the verses are more Similarity investigative and in verse 49 Similarity investigative and in verse 25.
The rush of Albulageyen and many other examples of Quranic Vmtheloa on Similarity , with a linguistic analysis and return to the origins of the meanings are not properly counted Similarity , Kolvaz cunning , deception , and maliciousness , the bad and ridicule.
This study seeks as much as possible to the statement of this phenomenon and stand on these t
There is an association between the signifier and the signifier. This association shows the eyeball, which acquires a direct presence and whose presence influences the level of production of the hidden connotation. Because the theatrical presentation is a series of auditory-visual functions, these signs are looking for the exploration of their meanings and their evocation to form a complete loop to achieve the association of the above. This is what made the researcher to monitor the abundance of semantic shifts in theatrical presentation as long as the implications of the strategy continue in the game of semantic production with multiple horizons, and the idea in theatrical presentation tolerates multiple readings according to the refere
... Show More
This research is interested in studying the constant and the variable within the signing reality in Iraqi Kurdistan region, and the researcher tries to tackle the importance of this topic within a search that serves the Kurdish culture, and contribute to its intellectual settlement, and introducing it to centers concerned with studying singing and music science in any civilized environment, whether inside or outside the territory of Kurdistan region. We see that this research which dealt with the topic (the constant and the variable in the Kurdish signing between the past and the present) deserves research and investigation for all its causes, being one of the academic necessities that contribute in identifying the historic artist
... Show More
(1)
Increasingly, public organizations in the federal state are required to work together, as well as to work with others to achieve their objectives. In Iraq there are two levels of organizations, including federal and local, and these organizations have been forced to work for many years in an environment in which the responsibility for service delivery is shared between policy makers and service providers, and between local governments and the federal government. It is sometimes difficult to manage the relationship between these organizations (federal and local) and do not always provide the best possible outcome of this relationship. This paper reviews how to manage the relationship between local administrations and
... Show More
The research abstract included introduction and the importance of the research, also included display of the problem represented by weakness for the players when performing some of the basic skills in badminton and the shuttle not reaching to the back corners of the court which gives the player the opportunity to win through applying the pressure on the opponent and make him away from the control center(T) which definitely required level of a collection muscular strength contributed in performance perhaps this related to a number of reasons related with weakness in physical changes especially explosive and characterized by speed forces for the badminton players and be acquainted with them and knowing the extent of their effect in performanc
... Show More
The experiment was carried out in the green house of botanical garden belong to Department of Biology/College of Education for Pure Science- Ibn–al- Haitham/University of Baghdad, for the growth season 2015 using plastic pots. The experiment aimed to study the effect of two concentrations of sodium chloride (50, 100) mM.L-1 in addition to the control and four concentrations of kinetin (25, 50, 75, 100) mg.L-1 in addition to the control and the influence of application and non application of fertilizlizer NPKZn in the level 160 kg.h1- and their interactions on some growth parameters (fresh weight for both root and vegetative part, dry weight for leaves , value of secondary productivity, biomass duration for vegetative part and dry weight f
... Show More
(1)
(2)
A poetic vision appeared in the poem of Al-Abbas bin Mardas Al-Sulami. He lived in the eras of pre-Islamic times and the emergence of Islam. The focus of this research: is the study of poetic text in the pre-Islamic era and the era of early Islam. The research followed a method in treating poetic texts, as it is based on presenting poetic texts from the collection of Al-Abbas bin Mardas, explaining the features of his poetic vision, and examining all the external factors that surrounded the poet and influenced his vision and all his thoughts. The results of this research was that Al-Abbas Ibn Mardas revealed some of the positions that he found contradicted the authentic Arab value before the advent of Islam, and the poet Abbas bin Mardas tr
... Show More