Current Issue : October - December Volume : 2015 Issue Number : 4 Articles : 6 Articles
Solar energy is very useful in the process of desalination especially for areas that suffer from a\nlack of clean water resources. In recent years, many people have been using solar still. Therefore\nthe raising of the productivity and efficiency of solar still represents the most important problems\nthat need further research. The present work aims to study the effect of preheating the water entering\nto still and the effect of reducing pressure inside the still on the productivity of the solar\nstill. Therefore in present work two identical single basin typical double slope solar stills of the\ninner basin dimensions for each still 2 m Ã?â?? 1 m Ã?â?? 0.08 m, have been designed and fabricated with\nmild steel plate. One of them is conventional solar still and the other is modified with flat plate\ncollector and vacuum pump to study the effect of preheating and vacuum on the performance of\nsolar still. The experimental measurements are made to enhance the solar still productivity by\nfirstly preheating the water entering the still using flat plate collector and secondly by integrating\nthe still basin with vacuum pump. The results show that preheating the water entering the still increases\nthe water productivity by amount about 27.7% - 29.3%. The results also show that decreasing\npressure inside the still using vacuum pump improves the solar still water productivety\nby amount about 21.8% - 23.9%....
Water hyacinth, E. crassipes, an invasive water weed thrives in fresh water bodies causing serious\nenvironmental problems. In Kenya the weed has invaded Lake Victoria and poses great socioeconomic\nand environmental challenges. Currently the weed is harvested from the Lake and left in\nthe open to rot and decay leading to loss of aesthetics, land and air pollution. There is therefore\nneed for development of value addition and economic exploitation strategies. The aim of the study\nis to assess the potential for utilization of the weed as a renewable energy resource for biogas production.\nSamples were collected from Lake Victoria, pulped and blend with cow dung at a ratio of\n3:1 as inoculum. The resultant mixture was mixed with water at a ratio of 1:1 and fed into a 6 m3\ntubular digester. The digester was recharged with 20 kg after every three days. The temperature,\npH variations, gas compositions, upgrading and gas yields were studied. The temperature ranged\nbetween 22.8 - 36.6 and pH 7.4 - 8.5. Biogas was found to contain 49% - 53% methane (CH4),\n30% - 33% carbon dioxide (CO2), 5% - 6% nitrogen (N2) and traces of hydrogen sulphide (H2S).\nThe biogas was upgraded using solid adsorbents and wet scrubbers increasing the methane content\nby up to 70% - 76%. The upgraded gas was used to power internal combustion engines coupled\nwith an electricity generator and direct heat applications. The study concludes that E. crassipes\nis a potential feedstock for biogas production especially in areas where it is abundant....
Rapidly increasing consumption and consequent depletion of reserves clearly show that the end of the fossil fuel age is not far. Besides there fuels are the chief contributors to urban air pollution and major sources of green house gases. Since Biodiesel can be operated in almost all diesel engines, it offers an immediate displacement of petroleum. Biodiesel technically is sold off at high cost due to the complex processing protocol. Biodiesel production also makes by-products that are of significant market value. In fact, the economic viability of today’s Biodiesel industry is so sensitive that the overall economic viability is highly dependent the market price of these byproducts....
This paper aims to study the impact of the Fermeuse wind farm (4658'42\"N 5257'18\"W) through\nsimulation of wind turbines driven by doubly fed induction generator which feed AC power to the\nisolated utility grid of Newfoundland. The focus is on the determination of both voltage and system\nstability constraints. The complete system is modeled and simulated in Matlab Simulink environment....
According to surveyed literature, there may be a health hazard associated with extremely low\nfrequency magnetic fields. This study aims at presenting a recent survey of this literature. It also\naims at measuring magnetic field levels close to power transmission lines at inhabited areas in\nKuwait to see if current levels are safe and to establish a database of 50 Hz magnetic field levels at\ninhabited areas. Measurements were made, according to the international standard procedures in\nwinter, spring, summer and fall, and three times of a day. Four inhabited areas were surveyed.\nResults provide us with an independent view of the levels in the vicinity of power lines and houses.\nResults show that the highest level is measured in the summer, reaching 115 mG while the minimum\nlevel is measured in the fall. We found that some houses were at less than 50 meters distance\nfrom the edge of the transmission lines. Some houses were, as close as 22 meters to the line. We\nfound that levels at the entrance of houses and at outdoor parking areas were mostly higher than\n4 mG....
Load forecasting is vitally important for electric industry in the deregulated economy. This paper\naims to face the power crisis and to achieve energy security in Jordan. Our participation is localized\nin the southern parts of Jordan including, Ma�an, Karak and Aqaba. The available statistical\ndata about the load of southern part of Jordan are supplied by electricity Distribution Company.\nMathematical and statistical methods attempted to forecast future demand by determining trends\nof past results and use the trends to extrapolate the curve demand in the future...
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