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.
Aim: This study aimed to investigate the impact of rabbit serum on skin wound healing with the help of histological examination. Materials and Methods: A total of ten indigenous rabbits were used in this study. The animals were divided into two groups: control and serum- treated. The histological assessment was done with a paraffin embedding technique and the histological sections were stained with H&E stain. Results: Severe infiltration of polymorphonuclear leukocytes with severe fibrin deposits were seen in serum treated group at 2 days post-injury; at 7 days post-injury the changes revealed moderate fibroplasia, fibrin deposit and severe infiltration of both mononuclear and polymorphonuclear leukocytes; at 14 days post-inju
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Sheets of Epoxy (EP) resin with addition of TiO2 of grain size (1.5μm, and 50nm) and weight percentage (1%, 3%, and 5%) were prepared. Discs of 20mm diameter and 3mm thickness were cut for dielectric measurements. Dielectric properties (dielectric constant, dispassion factor and electrical conductivity) over the frequency range 102 -106 Hz were measured.
Comparison was made between the effect of micro and nano particles of TiO2 on the dielectric properties of EP composites with different weight percentage. Epoxy composites with micro sized particles of TiO2 were observed to have the better values of dielectric properties.
This research aims to identify the role of radio advertising in promoting purchasing decisions of Iraqi audiences, especially that the placement of the announcement through the Iraqi radio stations dealt with a little of Iraqi researchers, and the goal of the research to know the extent of public exposure to the radio advertising through Iraqi radio and patterns of exposure,disclosure of the reasons for public hearing of the radio advertisement, identifying the most important factors influencing the decision to buy in the radio advertisement, this research is descriptive in terms of type as the researcher used the survey method,questionnaire and scale for data and information collection, the sample was selected according to the purp
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The paper discusses the lack of a uniform definition of politeness due to the constant tension between its universality and language specificity, and argues that some of the theoretical debate could be resolved if the distinction between politeness as a commonsense notion and politeness as a theoretical construct were clearly addressed and acknowledged in the research.
Investigation of the adsorption of acid fuchsin dye (AFD) on Zeolite 5A is carried out using batch scale experiments according to statistical design. Adsorption isotherms, kinetics and thermodynamics were demonstrated. Results showed that the maximum removal efficiency was using zeolite at a temperature of 93.68751 mg/g. Experimental data was found to fit the Langmuir isotherm and pseudo second order kinetics with maximum removal of about 95%. Thermodynamic analysis showed an endothermic adsorption. Optimization was made for the most affecting operating variables and a model equation for the predicted efficiency was suggested.
Background: The quality of drinking water is directly related to community health. Therefore, improving the quality of drinking reflects positively on the health situation in general. The studies that deal with the quality of drinking water in the city of Baghdad in terms of chemical or microbial content are very scanty. Objective: The current review highlights the most important studies and research articles that concern the quality of drinking water, both bottled water and tap water, in terms of chemical and biological contamination and chemophysical specifications for drinking water. Abstract: Studies have shown that drinking water in the city of Baghdad, especially tap water, contains certain levels of heavy metals,
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The study focused on the results of first paleostress from thrust fault slip data on Tertiary age of Hemrin North Structure, North of Iraq. The stress inversion was performed for fault slip data using an improved right dihedral model, and then followed by rotational optimization (Georient Software). The trend of the principal stress axes (σ1, σ2 and σ3) and the ratio of the principal stress differences (R) show the main paleostress field is NE-SW compression regime. As well as using Lisle graph and Mohr diagram to determine the magnitudes of palestress. The values paleostress of the study area were σ1=1430 bars, σ2=632 bars and σ3=166 bar. The large magnitudes of the primary stress axes could be attributed to active tecto
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Extensive evaluation of 76 women with polycystic ovary syndrome compared with 25 fertile women as control group was achieved by routine investigations and hormonal study of each female which were done in one period during the menstrual cycle. Then the women with PCOS have been divided into 2 groups according to their menstrual cycle (irregular menstrual cycle) during assessing their hormonal profiles as follow:- 1- (54) Patients with oligomenorrhea. 2- (22) Patients with menorrhea. This study shows that the women with PCOs have different clinical features taken from a history of disease of all of the women. Those features were distributed as follow: 57.92% of them suffer from hirsutism. 19.24% suffer from irregular menstr
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In the present study, semi – batch experiments were conducted to investigate the efficiency of ozone microbubbles (OMBs) in the treatment of aqueous dye solutions methylene orange under different reaction conditions such as effect of initial solution pH , ozone generation rate and initial MO-concentration. The results showed that the removal of MO by OMBs were very high at the acidic and alkaline media and upon increasing the generation rate of ozone from 0.498 to 0.83 mg/s, the removal efficiency dramatically increased from 75to 100% within 15 min. The rate of oxidation reaction followed a pseudo first- order kinetic model. The results demonstrated that OMBs is efficient in terms of the decline of methylene orange c
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