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%.
The linguistic meaning of the verse in the Arabic dictionaries applies very much to the reality of rent and its effect. This is true of economic growth as a continuous increase in real per capita income in addition to the same thing. Therefore, development does not necessarily achieve a comprehensive and structural increase of the various economic sectors. As the rent came in the sense of a terrible land open Maim any fertilized. And the camel is a ma'aya and a ra'i: that is, it goes in the pasture and returns itself. This is similar to the extraction of oil after it is ready for investment and earn its revenue as soon as it exists or is extracted by external parties. If the rent is first linked to agriculture, especially the fertile lan
... Show MoreThe post-Corona Covid-19 world is not the world before it, the problem of perception of personality traits with two axes: the characteristics of psychological and social compatibility, and the second aspect the mental disorder during the pandemic, and the accompanying precautions and prohibitions during the academic year 2020 AD. The aim of the research is to reveal the perception of the personal characteristics of Bisha University employees (students and faculty) during the Corona Covid-19 pandemic, and to reveal statistically significant differences in the perception of the personality traits of Bisha’s members during the Covid 19 according to the scientific qualification variables (female students -faculty members), marital st
... Show MoreThe upbringing of Yehuda Amichai and the conditions he lived in had a great influence on his deep sense of pain, which made him think of death and suicide. Especially after the Nazis came to power in Germany, and his emigration with his family. Amichai searched for love throughout his life, and his failure was one of the most important factors affecting his psyche, which is A deep influence that made him live in harsh and painful pains that broke him, and prevented her from achieving his ambitions in life.Dramatic texts are characterized by repetition in writing and presentation. It is a textual discourse that has two advantages, first, that it can be read as a literary text like all other literary texts, and second, that it can be consider
... Show MoreTax revenues are considered one of the important sources of public revenues for the state as one of the tributaries that finance the public treasury to implement development plans. Real estate taxes are one of the sources of obtaining tax revenues in the state, as it follows that there are a number of factors that affect these revenues, which requires the development of necessary solutions and recommendations to address the resulting effects. Accordingly, this research sheds light on tax revenues in general and real estate tax revenues in particular to indicate the extent of their contribution to the total tax proceeds, as the tax proceeds of the real estate tax were analyzed into the total tax proceeds for the years (2017-2021). A numbe
... Show MoreThis study aims at identifying thinking, its aspects, controls, thinker’s characteristics, and the attempts that followed by Ibrahim’s people. This was achieved under Ibrahim’s story, (peace and blessing be upon him), in the Holy Qur’an. The study used the descriptive method through induction and deduction. The study reached the following results: thinking is an organized reasonable human action, which includes all human life in the fields of science, knowledge, and calling for Allah. It depends on remembering what is already in the memory and it should be subjected by revelation and Islamic legislation. The study illustrated that the most important thinking controls are monotheism, piety, Islamic legislation, the Holy Qur’an,
... Show MoreThe study aimed to identify the role of the teacher in confronting intellectual extremism in high school students, and identify the differences of statistical significance in the role of teacher in confronting intellectual extremism in secondary school students according to gender variable (males, females) and the duration of service (less than 5 years more than 5 years), the sample was consisted of (100) teachers with (50) male and (50) female in the city of Bayaa, Dora and Sadiya, the measure of intellectual extremism was applied by the researcher, and the study reached a role of the teacher in facing the intellectual extremism at Secondary school students, and the existence of differences of statistical significance in the role
... Show MoreIH Abdul-Abbas, QJ Rashid, M RasimYounus, PalArch's Journal of Archaeology of Egypt/Egyptology, 2021 - Cited by 9
Everywhere carriers incur a measure of liability for the safety of the goods. Carriers are liable for any damage or for the loss of the goods that are in their possession as carriers unless they prove that the damage or loss is attributable to certain excepted causes. Damaged and lost items can unfortunately be a common problem when shipping freight. Legal responsibilities arise due to loss or damage during transit while cargo is in their care. This study intends to investigate the nature of the liability of the maritime carrier when this liability is realized, and the extent to which it can be paid or disposed of given the risks realized from the transportation process, which may result in damage or loss of the goods, and the damag
... Show MoreThe operation of production planning is a difficult operation and it's required High effect and large time especially it is dynamic activity which it's basic variables change in continuous with the time, for this reason it needs using one of the operation research manner (Dynamic programming) which has a force in the decision making process in the planning and control on the production and its direct affect on the cost of production operation and control on the inventory.