Solar photovoltaic (PV) has many environmental benefits and it is considered to be a practical alternative to traditional energy generation. The electrical conversion efficiency of such systems is inherently limited due to the relatively high thermal resistance of the PV components. An approach for intensifying electrical and thermal production of air-type photovoltaic thermal (PVT) systems via applying a combination of fins and surface zigzags was proposed in this paper. This research study aims to apply three performance enhancers: case B, including internal fins; case C, back surface zigzags; and case D, combinations of fins and surface zigzags; whereas the baseline smooth duct rep
In this study, the optical and thermal performance of a Parabolic Trough Collector PTC system is investigated theoretically. A series of numerical simulations and theoretical analysis has been conducted to investigate the effect of the receiver geometry and location relative to the focal line on its optical performance. The examined receiver geometries are circular, square, triangular, elliptical and a new design of circular‐ square named as channel receiver. The thermal performance of PTC is studied for different flow rates from (0.27 to 0.6 lpm) theoretically. Results showed that the best optical design is the channel receiver with an optical efficiency of 84% while the worst is the elliptical
Schiff bases were prepared prepared Baaan NMR to some elements of which have contributed to the results of different methods in diagnosis prove structural formulas of compounds prepared
Objective(s): To determine the prevalence and predisposing factors of psychology & personality types among
infertile and fertile women attending in Complex Imam Khomeini Hospital.
Methodology: A total of 150 infertile women from Vali-Asr Reproduction Health Research Center and 150 fertile
women from the Gynecology Clinic of Imam Khomeini Hospital in Tehran / Iran were chosen by simple
randomization. Data was obtained by using Eysenck personality (EPQ) and structured researcher questionnaires.
Results: showed that based on Eysenck personality questionnaire (EPQ), personality instability was more common
among infertile women than fertile women; this relationship was statistically significant (P<0.001). Housewives
This study attempts to focus on there lation ship between employment policies andsocietal changesinIraq.Theconstruction ofoperational policyincommunitiesin crisis remains fraught with challenges and risks, especially in countries that have longoutstanding conflict sand crises, it is important in this context to achieve those policy and build the foundations of human security and poverty alleviation, unemployment, to find effective ways to help the community to achieve stability and reduce the risk of renew edorrepeat the cycleofviolence-butthatwouldrequirearadicalrethinking, including rethinking the way evaluating therisksandchallengesand management.And thatsuchaprojectshouldbe based ona clear roadmap, andthevisionsofdevelopmentanda clea
... Show MoreThis study try to discovering continuity in heritage, from its engaged with emotional side, the core of study is Islamic architectural, these architectural result still estate with time, due to role of it with Islam law, importance of continuity from finding real things of essential architects result The research reaching to concept of thoughtstaying, for Islamic heritage, as basic factor in continuity process by it is architecture. The mostly searches seeing imitation of figures as recently events, or as final result to stage conditions state, but we must remember the Islamic thinking as base stone to architecture results
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New derivatives of pyromellitamic diacids and pyromellitdiimides have been prepared by the reaction of one mole of pyromellitic dianhydride with two moles of aromatic amines, these derivatives were characterized by elemental analysis, FT-IR and melting point.
Stress is an inevitable part of life. Stress occurs when stressful events of self, environmental, or social origin affect the individual's resilience and threaten to collapse his psychological and physical systems. The stress represents difficulties and obstacles that may exceed the individual's ability to bear them and deal with them, which causes him stress and causes negative effects on his psychological and physical health. Therefore, the current research aimed to identify the negative effects of psychological stress on the psychological and physical health of the individual through the literature that dealt with this topic. It was among the results of the research that one of the negative effects of stresses on mental health is the
... Show MoreBackground: Obesity has become one of the most important public heath problems all over the world.An epidemic of obesity is affecting children and adolescents across the developed and developing countries in recent years. As the prevalence of obesity increased, so did the prevalence of co morbidities like metabolic and endocrine diseases.Objectives: To overview obesity clinical features and the prevalence of associated co morbidities in children and adolescents attended the obesity researches and therapy center in Alkindy medical collage.Type of study: This is a cohort observational studyMethods : Obese child and adolescents aged 4-15year attended the obesity research and therapy unit in AL Kindy medical collage from the 1st of September
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