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.
Background: Poly propylene fibers with and without silane treatment have been used to reinforce heat cure denture base acrylic but, some mechanical properties like transverse strength, impact strength, tensile strength, hardness, wear resistance and wettability. Which are related to the clinical use of the prosthesis are not evaluated yet. The aim of the study is to identify the influence of incorporation of treated and untreated fibers on these properties Materials and methods: Eighty four heat cure acrylic specimens were constructed by conventional flasking technique. They were divided into six groups according to the tests and each group was subdivided into two subgroups control and experimental groups (seven samples for each subgroup
... Show MoreThe current research aims to develop the skills of the kindergarten students in designing and implementing a theater for gauntlets made of cardboard materials. To study this, the researcher determined to build teaching plans for design and implementation skills according to (Kolb model).
The results of this research showed the effectiveness of teaching plans according to (Kolb's model) in developing skills of design and implementation (theater for gauntlets made of cardboard materials) for the students of the Kindergarten Department - the experimental group. Which had a positive effect to reach the desired results in the design and implementation of the gauntlet theater and dealing with cardboard materials
The examination of gills of the common carp Cyprinus carpio revealed the presence of two species of the family Trichodinidae belonging to the genus Dipartiella (Raabe, 1959) Stein, 1961 namely D. indiana Saha and Bandyopadhyay, 2017 and D. kazubski Mitra and Bandyopadhyay, 2009 for the first time in Iraq from Al-Graiat location on the Tigris River at Baghdad city. This also represents the first record of the genus Dipartiella from fishes of Iraq. The descriptions and measurements of these two parasite species as well as their illustrations were given.
This paper aims at the fact that most organizations today suffer from a waste of time, effort, and cost, and they have difficulty in achieving the best performance situations and compete strongly. The researcher distributed 108 questionnaires as a statistical analyzable sample society where the sample intentionally consists of general managers, department head, and division head. The questionnaire was formulated according to the Likert scale. The use of personal interviews and observations are additional tools for data collection and a number of statistical methods is used for data analysis such as simple regression and correlation coefficient (Pearson). One of the most prominent conclusions is that the company has adequate and c
... Show More
(1)
Background: Posterior superior alveolar artery (PSAA) is branch of the maxillary artery. It usually supplies the lateral wall of the sinus and overlying membrane. Evaluation and awareness of the anatomy of maxillary sinus before surgery is crucial to avoid surgical complications. The aim of this study is to examine the prevalence, location of the (PSAA) in relation to the floor of the maxillary sinus and alveolar crest using computerized tomography (CT) scans. Materials and Methods: This study included 180 Iraqi subjects (99 males and 81 females) with age more than 16 years old. CT scans for (right and left) Maxillary sinuses were done for each patient. The information obtained was assessed in a coronal multi planar reconstructions images (
... Show More
(1)
The current study aimed to reveal the moral values available in the Arabic language textbook (Al-Mu’nes) for grades eleven and twelve for post-basic education in the Sultanate of Oman. The researcher adopted the descriptive approach using the sentence as measuring unit in the analysis process. The five fields of moral values and their subcategories values represented the categories of the analysis. Iterations of values and the percentages of iteration were calculated in those textbooks. Moreover and the analysis and stability of the process were confirmed.
After referring to previous studies, it was possible to de
... Show MoreThe experiment was carried out to study the effect of variety and gibberellic acid in concentration (0 and 50)mg.lat-1 and BL in five concentration (0, 0.50 ,1 ,2 and 3)mg.ltr-1 and their interaction in some chemical Characteristics and total chlorophyll for Dill plant . the experiment designed according Randomized Complete Block Design (RCBD) and three replicates per treatment, compared to the average using less significant difference at the level of probability (0.05) , the results showed the following:- The effect of brassinolide with it,s concentrations led to obtain a significant increase in all the studied characteristics, so the superiority of the concentration of 2 mg.L-1 of brassinolide in each of Ca, Mg,Fe, and total chlorophyll T
... Show More
(25)
: Cervical cancer representsone of the possibly preventable cancer. The study was designed to find the possible correlation of Tafazzin on the progression of cervical carcinoma. Two groups of paraffinized blocks were included. The study group of 30 cervical tumors as well as 15 biopsies of healthy cervical tissues. After sectioning on a positive charge, immunohistochemical application (IHC) was performed to detect Tafazzin expression. Nighnty percentage (27 out of 30) of the studies group showed positive overexpression as shown in with a significant association of the expression with cervical cancer with a significant association. There is a possible role of TAZ in hastening the development of cervical cancer through different mechanisms. F
... Show More