The thermal and electrical performance of different designs of air based hybrid photovoltaic/thermal collectors is investigated experimentally and theoretically. The circulating air is used to cool PV panels and to collect the absorbed energy to improve their performance. Four different collectors have been designed, manufactured and instrumented namely; double PV panels without cooling (model I), single duct double pass collector (model II), double duct single pass (model III), and single duct single pass (model IV) . Each collector consists of: channel duct, glass cover, axial fan to circulate air and two PV panel in parallel connection. The temperature of the upper and lower surfaces of PV panels, air temperature, air flow rate, air pressure drop, wind speed, solar radiation and ambient temperature were measured. The power produced by solar cells is measured also. A theoretical model has been developed for the collector model IV based on energy balance principle. The prediction of the thermal and hydraulic performance was obtained for the fourth model of PV/T collector by developing a Matlab computer program to solve the numerical model. The experimental results show that the combined efficiency of model III is higher than that of models II and IV. The pressure drop of model III is less than that of models I and IV, by (43.67% and 49%). The average percentage error between the theoretical and experimental results was 9.67%.
This study was carried out to measure the percentage of heavy metals pollution in the water of the Diyala river and to measure the percentage of contamination of these elements in the leafy vegetables grown on both sides of the Diyala river, which are irrigated by the contaminated river water (celery, radish, lepidium, green onions, beta vulgaris subsp, and malva). Laboratory analysis was achieved to measure the ratio of heavy element contamination (Pb, Fe, Ni, Cd, Zn and Cr) using flame atomic absorption spectrophotometer during the summer months of July and August for the year 2017. The study showed that the elements of zinc, chromium, nickel and cadmium were high concentrations and exceeded. The maximum concentration of these
... Show MoreSummary First: The importance of the study and the need for it: The society is composed of an integrated unit of groups and institutions that seek to achieve a specific goal within a system of salary, and the family remains the most influential institutions on the individual and the unity of society, with the roles and responsibilities of the individual and society, and through the continuation and strength of other social organizations derive their ability On the other hand, any break-up in the institution of the family is reflected negatively on the cohesion of society and its interdependence, and the causes of this disintegration vary from society to another, but family problems remain the main factor in obtaining it. Second: Study Ob
... Show MoreExtensive 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
... Show MorePorosity and pore structure are important characteristics of pharmaceutical tablets, since they influence the physical properties, such as mechanical strength, density and disintegration time. This paper is an attempt to investigate the pore structure of four different paracetamol tablets based on mercury porosimetry. The intrusion volumes of mercury were used to calculate the pore diameter, pore volume and pore size distribution. The result obtained indicate that the variation of the pore volume in the tablets followed the sequence:- S.D.I. Iraq? Pharmacare,Dubai-U.A.E.? Bron and Burk(UK) London?Lark Laboratories(India), while the variation of surface area followed the sequence:- S.D.I. Iraq? Lark Laboratories(India)? Pharmacare,Dubai-U.A
... Show MoreThe researchers go to the classification of the book (mortality of objects) of Ibn Khalkan in the books of biographies, translations and history and consider it an important dictionary in translations and this is not disputed, but none of them did not reveal clearly about the literary phenomenon in which it is clearly related and the size of this phenomenon, it has come in the side This research sought to investigate this critical encyclopedia, which occupied a large area of the historical framework of the book as we rarely found a figure in which did not turn - in extrapolation of translations - in the orbit of poetry as well as the great celebration of poetic speech during Translation has reached a number Perhaps the most promine
... Show MoreThis research aims to introduce a new technique-off-site and self-form segmental concrete masonry arches fabrication, without the need of construction formwork or centering. The innovative construction method in the current study encompasses two construction materials forms the self-form masonry arches, wedge-shape plain concrete voussoirs, and carbon fiber-reinforced polymer (CFRP) composites. The employment of CFRP fabrics was for two main reasons: bonding the voussoirs and forming the masonry arches. In addition, CFRP proved to be efficient for strengthening the extrados of the arch rings under service loadings. An experimental test was conducted on four sophisticated masonry arch specimens. The research parameters were the Keystone thic
... Show MorePlane cubics curves may be classified up to isomorphism or projective equivalence. In this paper, the inequivalent elliptic cubic curves which are non-singular plane cubic curves have been classified projectively over the finite field of order nineteen, and determined if they are complete or incomplete as arcs of degree three. Also, the maximum size of a complete elliptic curve that can be constructed from each incomplete elliptic curve are given.
Receipt date:06/23/2020 accepted date:7/15/2020 Publication date:12/31/2021
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The executive authority differs from one country to another, as it differs from a federal state to another according to the nature of the applied political systems, so this research focused on federal states according to their political systems, then going into the details of the executive authority and its role In the federal states by referring to the four federal experiments
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