The efficient behavior of a low-concentrating photovoltaic-thermal system with a micro-jet channel (LCPV/T-JET) and booster mirror reflector is experimentally evaluated here. Micro-jets promote the thermal management of PV solar cells by implementing jet water as active cooling, which is still in the early stages of development. The booster mirror reflector concentrates solar irradiance into solar cells and improves the thermal, electrical, and combined efficiencies of the LCPV/T-JET system. The LCPV/T-JET system was tested under ambient weather conditions in the city of Bangi, Selangor, Malaysia, and all data was recorded between 10:00 a.m. and 4:00 p.m. Parametric studies were conducted to compare the performance of the LCPV/T-JET system to that of a conventional PV module. It is found that the short-circuit current of a standard PV module could be increased by 28% and 11.7%, with and without the use of jet water and booster mirror reflectors, respectively. Moreover, the power supplied by the PV component increases to 31% and 16%, respectively, with and without jet water and a booster mirror reflector. The characteristic curves for current–voltage and power–voltage curves also confirmed the superior thermoelectric properties of the LCPV/T-JET system. The measurements reveal a drop in the electrical efficiency of solar cells from 14.5% to 12.25% as the temperature of the cells increases from 32.5 °C to 66.5 °C between 10:00 a.m. and 1:00 p.m. Meanwhile, the thermal and overall efficiencies declined from 84% to 81.5% and 96% to 93%, respectively.
In this study, the effect of the combination of micro steel fibers and additives (calcium hydroxide and sodium carbonate) on the size of cracks formation and healing them were investigated. This study aims to apply the use of self-healing phenomenon to repair cracks and to enhance the service life of the concrete structures. Micro steel fibers straight type were used in this research with 0.2% and 0.4% by volume of concrete. A weight of 20 and 30 kg/m3 of Ca(OH)2 and 2 and 3 kg/m3 of Na2CO3 were used as a partial cement replacement. The results confirm that the concrete cracks were significantly self-healed up to 30 days re-curing. Cracks width up to 0.2 mm were comp
... Show MoreNanocrystalline TiO 2 and CuO doped TiO 2 thin films were successfully deposited on suitably cleaned glass substrate at constant room temperature and different concentrations of CuO (0.05,0.1,0.15,0.2) wt% using pulse laser deposition(PLD) technique at a constant deposition parameter such as : (pulse Nd:YAG laser with λ=1064 nm, constant energy 800 mJ, with repetition rate 6 Hz and No. of pulse (500). The films were annealed at different annealing temperatures 423K and 523 K. The effect of annealing on the morphological and electrical properties was studied. Surface morphology of the thin films has been studied by using atomic force microscopes which showed that the films have good crystalline and homogeneous surface. The Root M
... Show MoreThe international order have been changed during the modern and contemporary history, and however those changing in international order doesn't go to beyond several concepts such as " balance of power";" conflict"; "power" and " threaten", which all those are depending on the fundamentals or basic terms which was called " power" or" hard power". In this time, we can say that the political relations among the effective units could be analyzed according to the concept of " balance of threaten" instead of the classic concept which had called " balance of power" that the scholars used to describe the international relations . In conclusion , the concept of " balance of threaten" has a significant importance in the studies of the internationa
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Our research was launched in the study of the sustainable conflict of globalization and the rebalancing of the great powers that have made life on the earth unstable and insecure over the past and present eras, the purpose of which is to pay attention to the waste and instability that human societies are exposed to in different proportions between abstract right and continuous deviation.
The purpose of the study is to show the loss, waste and backwardness in managing and governing societies towards private interests, away from the standards of good institutional governance.
The study’s design was based on two demands, the first on the nature and eternity of
... Show MoreThe performance of photovoltaic (PV) panel having staggered metal foam fins was examined experimentally in Baghdad, Iraq. Three staggered metal foam fin configurations attached to the backside of the PV panel were studied. The measured parameters were front and back surfaces temperature, open voltage and current circuits, maximum power, and PV efficiency. It was noted that the maximum electrical efficiency enhancement was 4.7% for staggered metal foam fins (case III) than the reference PV panel. The operating temperature of the cell was increased when the value of solar intensity was high. Thereby, the electrical efficiency was decreased. It was found that the metal foam fins decreased the PV temperature by 2-3 o
... Show MoreLevofloxacin belongs to the fluoroquinolone family; it is a potent broad-spectrum bactericidal agent. The pharmacophore required for significant antibacterial activity is the C-3 carboxylic acid group and the 4-pyridine ring with the C-4 carbonyl group, into which binding to the DNA bases occur. In this work, we tried to show that by masking the carboxyl group through amide formation using certain amines to form levofloxacin carboxamides, an interesting activity is kept. Levofloxacin carboxamides on the C-3 group were prepared, followed by the formation of their copper complexes. The target compounds were characterized by FT-IR, elemental analysis. The antimicrobial activity of the target compounds was evaluated and showed satisfactory resu
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Most of the industrial organization in the world became suffering from the problem of the pollution of the poisonous chemicals things, this urged to depend on the principle of the responsible production, because it has the positive role by dealing with these chemical things and to safe the health of the society, due to the main goal of this study is to restrict the role responsible production in accomplishing the system of the environmental management through an actual study in the northern gas company in Kirkuk province, the topic has acquired a big importance bacause there were a limited number of studies and res
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