This paper presents an experimental study of cooling photovoltaic (PV) panels using evaporative cooling. Underground (geothermal energy) water used to extract heat from it during cooling and cleaning of PV panels. An experimental test rig was constructed and tested under hot and dusty climate conditions in Baghdad. An active cooling system was used with auxiliary an underground water tank to provide cold water as a coolant over both PV surfaces to reduce its temperature. The cellulose pad has been arranged on the back surface and sprays cooling on the front side. Two identical PV panels modules used: without cooling and evaporative water cooling. The experiments are comprised of four cases: Case (I): backside cooling, Case (II): front and back cooling (pump supply water every 35 minutes), Case (III): cooling both sides using Arduino controller. Water cooling pump operation depending on the panel temperatures (temperature sensors were installed on the front of the panel), Case (IV): Repeating case III with different water flow rates. Experimental results showed that the average reduction in module temperatures was 4, 8,12.2 and 12.6 ⁰C respectively by Case (I), (II), (III) and (IV) with respect to a non-cooling module. Using evaporative water cooling achieved a total improvement of 1.74%, 2.8%, 15.8%, and 16% in the conversion efficiency of the panel by the Case (I), (II), (III) and (IV) respectively when compared to a non-cooling module.
To evaluate the bioactivity and the cytocompatibility of experimental Bioglass-reinforced polyethylene-based root-canal filling materials. The thermal properties of the experimental materials were also evaluated using differential scanning calorimetry, while their radiopacity was assessed using a grey-scale value (GSV) aluminium step wedge and a phosphor plate digital system. Bioglass 45S5 (BAG), polyethylene and Strontium oxide (SrO) were used to create tailored composite fibres. The filler distribution within the composites was assessed using SEM, while their bioactivity was evaluated through infrared spectroscopy (FTIR) after storage in simulated body fluid (SBF). The radiopacity of the composite fibres and their thermal properties were
... Show MoreThis study investigated the shear performance of concrete beams with GFRP stirrups vs. traditional steel stirrups. Longitudinal glass fiber‐reinforced polymer (GFRP) bars were used to doubly reinforce the tested beams at both the top and bottom of their cross sections. To accomplish this, several stirrup spacings were provided. Eight beam specimens, measuring 300 × 250 × 2400 mm, were used in an experimental program to test under a two‐point concentrated load with an equal span‐to‐depth ratio until failure. Four beams in Group I have standard mild steel stirrups of 8 mm diameter, while four beams in Group II have GFRP stirrups with the same adopted diameter. The difference betwe
This work investigates experimentally the effect of using a skirt with a square foundation of 100 mm width resting on dry gypseous soil (i.e., loose soil with 33% relative density), and subjected to an inclined load. Previous works did not study the use square skirted foundation rested on gypseous soil and subjected to inclined load. The investigated soil was brought from Tikrit city with 59% gypsum content. Standard physical and chemical tests on selected soil were carried out. Model laboratory tests were carried out to determine the effect of using a skirt with a square foundation on the load-settlement behavior of gypseous soil and subjected to inclined load with various Skirt depth (Ds) to foundation width (B) ratio
... Show MoreBackground: The quality of drinking water is directly related to community health. Therefore, improving the quality of drinking reflects positively on the health situation in general. The studies that deal with the quality of drinking water in the city of Baghdad in terms of chemical or microbial content are very scanty. Objective: The current review highlights the most important studies and research articles that concern the quality of drinking water, both bottled water and tap water, in terms of chemical and biological contamination and chemophysical specifications for drinking water. Abstract: Studies have shown that drinking water in the city of Baghdad, especially tap water, contains certain levels of heavy metals,
... Show MoreHuwaiza marsh is considered the largest marsh in the southern part of Iraq. It is located between 31° and 31.75° latitude and extends over the Iraqi-Iranian border; but the largest part lies in Iraq. It is located to the east of Tigris River in Messan and Basra governorates.
In this research, the variation of some water quality parameters at different locations of Huwaiza marsh were studied to find out its efficacy in the treatment of the contamination coming from the wastewater outfall of Kahlaa brokendown sewage treatment plant which lies on the Kahlaa River. This rive is the main feeder of Huwaiza marsh. Ten water quality sampling locations were chosen in this marsh. The water samples were taken during 2009 for three months; Janu
The electrochemical behavior of carbon steel in water sweetening station in Libya has been studied in the range of ( 293–333 oC) using weight loss technique. Measurements were carried out over a range of Reynolds number (5000 – 25000).An apparatus was designed for studying the corrosion process in the turbulent regime, which is of industrial significance. It was found that The corrosion rate of carbon steel in water sweetening station is under diffusion control and increases with increasing Reynolds number. On the other hand the variation of corrosion rate with temperature in the range of (293–333 oC) was found to follow Arrhenius equation and the activation energy approximately the same except at low Reynolds
... Show MoreABSTRACT The antibacterial and antbiofilm activities of water extract of Calendula officinalis flowers against some of enteropathogenic bacteria was studied, also phytochemical screening and determination of antioxidant activity of the extract has been investigated. The results showed that the water extract of C. officinalis exhibited a good antibacterial activity against all pathogenic bacterial isolates (Salmonella, Shigella dysenteriae, Shigella flexneri, Shigella sonnei and E. coli) especially at concentration 100 µg/ml in contrast with the control cefotan antibiotic. S. sonnei was more sensitive to extract than other bacteria with highest inhibition zone (23 mm). The preliminary phytochemical tests results indicated the presence
... Show MoreABSTRACT In dam construction stages when an earth embankment has retained a reservoir with constant water surface elevation for a long time, seepage conditions within the embankment will be reach a steady state. If it is necessary to drain the reservoir quickly, the pore-water pressures in the embankment may remain relatively high while the stabling effect of the reservoir's weight along the upstream (U/S) side for the embankment has removed. This process is referring to as "Rapid Drawdown" and may be cause instability in the upstream (U/S) face of the embankment. Kongele dam is one of the proposed earth dams to be implement within the current plan in Iraq. The authors study pore water pressure and the effect of rapid drawdown for the dam d
... Show MoreThe present work aimed to study the efficiency of thermal osmosis process for recovery of water from organic wastewater solution and study the factors affecting the performance of the osmosis cell. The driving force in the thermo osmosis cell is provided by a difference in temperature across the membrane sides between the draw and feed solution. In this research used a cellulose triacetate (CTA), as flat sheet membranes for treatment of organic wastewater under orientation membrane of active layer facing feed solution (FS) and draw solution (DS) is placed against the support layer. The organic materials were phenol, toluene, xylene and BTX (benzene, toluene, and xylene) used as feed solution. The osmotic agent in draw solution was
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