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 commercial job is one of the most important businesses in the cities as there is no city can exist without commercial markets to offer service to its inhabitants. This study aims to distribute the commercial function in Abu Tayara Street located in the municipality of Al-Dora by highlighting the size of such businesses in this street. It focuses on analyzing the change that has occurred due to the usages of the commercial land not only in the residential areas, but also in various aspects associated with the growth of the population in the city. Both expansion and development of the economic and social aspects in the area have increased the demand for commercial services. So, the research focuses on the aspects of functional speciali
... Show MoreEverywhere 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 MoreA field experiment is conducted to study the effect of different levels of peat (0, 25, 50, 75, and 100 Mg ha-1 to uncropped and cropped soil to wheat. Soil samples are taken in different period of time (0, 3, 30, 60, 90, 120, and 180 days after cultivation to determine (NaHCO3-Exteractable P at 3 different depths (0-10, 10-20, and 20-30 cm). Field Experiment is conducted in a randomized complete block design (RCBD) with four replicates. Wheat, Al-Rasheed variety, is cultivated as a testing crop. The entire field is equally dived in two divisions. One of the two divisions is cultivated to wheat and the second is left uncropped. The effect of five levels of peat namely 0, 25, 50, 75, 100 Mg ha-1 is investigated. Soils are fully analyzed
... Show MoreHaving signed my eyes on the manuscript labeled (equity in the ancestral quarrel at the meeting of subordinate and representative metaphors) I was impressed by the process of achieving it; That manuscript came to light; to be seen by specialists in Arabic rhetoric and students of science, and supplement the library of rhetoric one of the sources ..
The 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 MoreThe problem of the tagged research (experimentation in the works of the artist Muhammad al-Kinani is an analytical study) dealt with the nature of the concept of experimentation and its work in the works of Muhammad al-Kinani. Which adopts the removal of the concept of style and artistic style and takes the experience away from the pattern of repetition The importance of the research comes through the identification of the materials founding the artistic work. The current research benefits the specialists in the field of arts from the students of studies with a new and renewed formulation of creativity. The research objectives shed light on the contemporary experiences of the artist Muhammad Al-Kinani and its importance in benefiting res
... Show MoreFinance is considered as an important and essential element when developing any housing policy which has a basic role creation of channels and effective means of saving money for individuals and institutions involved in the construction of housing units , and in particular that there is a deficit of residential dramatically in Iraq offset by a significant decline in the rates of construction housing and the accumulation of housing need in the coming years , the importance lies of the subject in creating mechanism for financing this sector and the impact of such a mechanism in solving the problem of the deficit number of housing units, through studying the experiences of some countries in the policies of housing finance to take advantage
... Show MoreSemiconductor-based metal oxide gas detector of five mixed from zinc chloride Z and tin chloride S salts Z:S ratio 0, 25, 50, 75 and 100% were fabricated on glass substrate by a spray pyrolysis technique. With thickness were about 0.2 ±0.05 μm using water soluble as precursors at a glass substrate temperature 500 ºC±5, 0.05 M, and their gas sensing properties toward CH4, LPG and H2S gas at different concentration (10, 100, 1000 ppm) in air were investigated at room temperature which related with the petroleum refining industry.
Furthermore structural and morphology properties were scrutinize. Results shows that the mixing ratio affect the composition of formative oxides were (ZnO, Zn2SnO4, Zn2SnO4+ZnSnO3, ZnSnO3, SnO2) ratios ment
This study aims to identify how the Zakat Fund contributes to financing entrepreneurial projects; and the role that these projects play in achieving economic and social development, despite the importance that contracting projects have in most countries as the main engine of growth; however, they still face many challenges that In the forefront of which is the challenge of obtaining financing; in this regard, it is possible to resort to the use of Zakat funds in the Islamic economy as it is a funding source that is closely proportional to the characteristics and goals of entrepreneurial projects in achieving development;
 
... 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.