Current Issue : January - March Volume : 2015 Issue Number : 1 Articles : 6 Articles
In the current economic and political scenario of Pakistan where new projects of Electrical generation\nseems impossible, one should adopt such means so as to minimize the power consumption\nvia load management. In this paper a relatively better Electrical power system is proposed for\nUniversity of Gujrat (UOG) power system. UOG runs its all generators whether it is full load or\nmerely a load of 20 percent as a standby power. It is suggested that if generators system is synchronized\nand connected in parallel, it can not only minimize the cost, number of personnel required\nbut also increase the reliability of the system. ETAP software is used for simulation and\nresults show that by adopting this method generation cost can be reduced up to 30 percent which\nis indeed a huge figure. Losses and cable parameters were calculated using this software and\nfound this proposal quite feasible....
Different oil samples were collected from oilfields in the North Western Desert namely Meleiha, Razaak and Qarun fields. These oils were analyzed geochemically, including sulfur content, API gravity and gas chromatography The results showed that. API gravity and sulfur content indicate that the crude oils have high mature level of marine origin. Distribution of n-alkanes (CPI, Pri/Phy and isoprenoide/n-alkanes) reflects that the oil samples are originated mainly from marine organic sources deposited in reducing environment. This indicates that the oil samples under investigation are good correlated with each other in the western part of the North Western Desert....
An endoreversible model is used to simulate the dynamic behavior of a solar driven absorption\nrefrigerator, the cycle under different operating and design conditions. A global time minimization\nprocedure is performed to reach maximum performances. To evaluate the influence of the cold\ntemperature on the system�s performances, results are carried out for three values of this temperature.\nThey are presented in normalized charts for general applications. The minimum time\nset point temperature, entropy and maximum refrigeration load are sharp and therefore, are important\nto be considered for system design....
Current PV cells technology takes advantage mainly from beam radiation. In this context the sun trackers\nare such devices for efficiency improvement. On the other hand, projected shadows between\ndevices make mandatory to increase the distances between mounting systems. Thus, the\nlandââ?¬â?¢s capacity for mounting PV panels can be dramatically decreased. This fact conducts us to\nwonder where the optimum efficient point is. First, in this paper different types of sun-tracking\nsystems are classified according to the movement they perform (cinematic classification). Further,\nthree real PV installations-fixed, horizontal-axis tracking and dual-axis mount trackingââ?¬â?located\nin the same geographical area in Spain (they are approximately under the same weather conditions)\nare analyzed. These installations have been studied in order to establish which one is the\nmost efficient and affordableââ?¬â?Specific Energy Production (SEP) and Performance Ratio (PR)\nanalysis. PVGIS solar radiation estimate tool has been used for comparing the theoretical radiation\npotential on each plant. The land requirements have been considered in the analysis of the\nGround Cover Ratio (GCR) and the Surface Performance Ratio (SPR). Moreover, comparing three\nmain financial indicators let us carry out a financial study: Payback Time (PBT), Net Present Value\n(NPV) and Internal Rate of Return (IRR). In the case study, final annual energetic results demonstrate\nthat the dual-axis plant shows a relevant SEP advantage, but if we take into account the land\noccupied for this sort of devices we find much more profitable the horizontal-axis sun-tracking\nsystem, with a SPR value 4.24% higher than the fixed system we have studied. Its PBT is also a 22%\nlower than the dual-axis tracking installation....
In this paper, we propose a H? robust observer-based control DC motor based on a photovoltaic\npumping system. Maximum power point tracking is achieved via an algorithm using Perturb and\nObserve method, with array voltage and current being used to generate the reference voltage\nwhich should be the PV panel�s operating voltage to get maximum available power. A Takagi-\nSugeno (T-S) observer has been proposed and designed with non-measurable premise variables\nand the conditions of stability are given in terms of Linear Matrix Inequality (LMI). The simulation\nresults show the effectiveness and robustness of the proposed method....
A sauna drying techniqueââ?¬â?the solar drier was designed and imposed, constructed and tested\nfor drying of seaweed. The seaweed moisture content was decreased around 50% in 2-day sauna.\nKinetic curves of drying of seaweed were known to be used in this system. The non-linear regression\nprocedure was used to fit three different drying models. The models were compared with\nexperimental data of red seaweed being dried on the daily average of air temperature about 40C.\nThe fit quality of the models was evaluated using the coefficient of determination (R2), Mean Bias\nError (MBE) and Root Mean Square Error (RMSE). The highest values of R2 (0.99027), the lowest\nMBE (0.00044) and RMSE (0.03039) indicated that the Page model was the best mathematical\nmodel to describe the drying behavior of sauna dried seaweed. The percentage of the saved time\nusing this technique was calculated at 57.9% on the average solar radiation of about 500 W/m2\nand air flow rate of 0.056 kg/s....
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