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.
That less duration takes larva mature into a virgin under field conditions is one day during Alguetrh from April to October and last longer to more than a day during Alguetrh from November to February and up to nine days in January when low minimum temperature to zero degreespercentage that these larvae can not be a high percentage in the field ranging from 90-100% reduced Hessian Alnsphaly 85% during the months of July and Cape
General Directorate of Surveying is considered one of the most important sources of maps in Iraq. It produced digital maps for whole Iraq in the last six years. These maps are produced from different data sources with unknown accuracy; therefore, the quality of these maps needs to be assessed. The main aim of this study is to evaluate the positional accuracy of digital maps that produced from General Directorate of Surveying. Two different study areas were selected: AL-Rusafa and AL-Karkh in Baghdad / Iraq with an area of 172.826 and 135.106 square kilometers, respectively. Different statistical analyses were conducted to calculate the elements of positional accuracy assessment (mean µ, root mean square error RMSE, minimum and maxi
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Islamic periodicals are defined as: publications issued periodically, and containing articles, research, or studies that convey Islamic thought and culture. Islamic periodicals have a prominent place among other types of sources of documentary and non-documentary Islamic information, because they are characterized by the speed of their issuance and the modernity and diversity of their Islamic information. This study aims to explain the reality of Islamic periodicals published in Iraq, graphically analyze their bibliographic characteristics and emphasize the importance of their issuance, as well as give a historical overview of the issuance and publication of Islamic periodicals in the Arab world and the world, while presenting examples of I
... Show MoreIraqi provinces suffer many of the environmental problems, appear explained these problems in the city of Basra, Basra, the largest province and is among Iraq's provinces in the annexation of oil fields, which is experiencing an oil production operations of large, it suffers from the burning of gas associated with oil extraction resulting in the emission severe gas process including toxic hydrogen sulfide gas (h2S) and oxides of carbon, sulfur and nitrogen in addition to the release of toxic metal elements such as mercury, arsenic, vanadium, which caused the man many serious diseases. , And perhaps one of the most important of these problems are worsening air quality and increasing cases of air pollution and the deterioration of the qual
... Show MoreIn this paper, the Normality set will be investigated. Then, the study highlights some concepts properties and important results. In addition, it will prove that every operator with normality set has non trivial invariant subspace of .
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This research is based on the study of a group of Quranic verses that share a certain part, and these verses are verses of righteousness, and the word righteousness has been mentioned in the Holy Qur’an eight times, and the number of verses in this word was six verses, in four walls, all of which are from the civil fence which is the cow and was There are five words of righteousness contained in them, and the family of Imran is one word, and the table is one word, and the argument is one word. This study adopts the method of analytical interpretation of the Quranic text is a term that means statement and clarification in a way that the researcher produces to divide a Quranic text into its elements that are involved in its formation and
... Show MoreThree plant species were picked randomly and their alcoholic extracts have been screened to know their effects on the phagocytic capability and intracellular killing of yeast by human peripheral macrophages. Macrophage cultures were incubated with different concentration of each plant extract: for 15 min., 30 min .and 45 min. The phagocytes activity in Iresine herbstii extract was significantly (p?0.05) increased with increasing dose and time of incubation. In Mentha piperita extract, increasing in dose and time of incubation leads to elevate phagocytic capbility, especially in the dose of 20% and 25% of plant extract, perhaps because the antimicrobial and antiviral activities of this plant, as well as strong antioxidant and antitumor act
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Historical concepts are among the concepts that are difficult to present to the pre-school child except by using modern techniques, as well as the difficulty of making visits to all historical monuments and going back to antiquity and the lack of studies in this area, therefore, we need an attractive medium that children love which is able to convey some abstract concepts that are difficult to teach to children using traditional methods, and among these activities that the kindergarten provides to children are the stories through which they develop their linguistic wealth, consolidate their religious and spiritual inclinations, refine their correct morals, and form their proper attitudes, knowledge and life concepts.
The
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