Browsing by Author "Ayesha Mohy-Ud-Din"

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    Characterization of biodiesel samples produced from fresh and waste vegetable oils to evaluate their feasibility for power generation
    (2013) Mehwish Inam; Ayesha Mohy-Ud-Din; Abdul Aziz Bhatti; Mashood Nasir
    The purpose of this paper is to design a system in which the biodiesel prepared from fresh and waste vegetable oil can be converted into useful power output. It is intended that this biodiesel produced may ultimately be a fuel source for the power generation from the generators. The optimal conditions of temperatures and concentration have also been discussed and the criteria to select these parameters have been evaluated.
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    Comparative analysis on the efficiency and engine properties by using biodiesel and fossil diesel
    (2013) Ayesha Mohy-Ud-Din; Mehwish Inam; Abdul Aziz Bhatti; Mashood Nasir
    The increase in the demand and prices of petroleum products as well as the environmental concerns resulting from the burning of fossil fuels in electricity production has resulted in focusing on the use of environmental friendly renewable alternative energy resources, like solar, hydro, tidal, wind, geothermal and biomass energy. There has been plenty of research done so far on engine performance and biodiesel production. Biodiesel was produced from fresh oil (BFO) and waste vegetable oil (BWO) on using biofuels for electricity generation. The engine performance tests were conducted with petroleum diesel and biodiesel samples at different loads and variable speeds. On comparing the electrical efficiency of generator and brake specific fuel consumption(BSFC) values, it was observed that less fuel is required for same power output when BFO (0.19kg/kWh) and BWO (0.18kg/kWh) were used in place of petroleum diesel. Moreover, an increase in BSFC values of BFO and BWO as compare to petroleum diesel at different speeds leads to the same interpretation. Higher efficiency and lower BSFC values of BFO (Efficiency: 43.25%; BSFC: 0.19 kg/kWhr) and BWO (Efficiency:41.34%;BSFC:0.2kg/kWh) due to complete combustion and reduction in calorific value of the fuel. In case of BWO, the operational efficiency (41.34%) was found less than the diesel-fueled condition.
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    Effect of syngas and coal composition on performance of solid oxide fuel cell
    (2012) Ayesha Mohy-Ud-Din; Mehwish Mujahid; Muhammad Hassan Qayyum Khan
    Gasification technology includes the conversion of fossil fuels into either combustible gas or synthesis gas (syngas) for subsequent utilization. It finds its applications in the production of clean power as well as chemicals. Coal is one of the world's important sources of energy fueling around 40% of the power stations around the world. It is commonly agreed that coal pits will be mined more intensively and in more numbers in the coming years and that lignite and hard coals will be the major energy suppliers until 2100. Integrated gasification fuel cell hybrid power generation system is a promising system for coal utilization. It combines clean coal gasification technology with high efficient fuel cell technology. In this paper, effect of syngas and coal composition on performance of solid oxide fuel cell was studied. It was observed that different ratios of H2 and CO affect the current and voltage of fuel cell. With higher molar fraction of H2 the better output voltage was obtained under the same working conditions. The trace species in coal also affect the performance of solid oxide fuel cell. Ni, Be, Cr, K and Na trace species present in coal also affect the performance to some extent.
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    GC-MS and HPLC as the analytical tools in solving the taxonomic controversies of plants
    (2013) Ayesha Mohy-Ud-Din; Muhammad A.Kashmiri; Z. Khan; Muhammad Mujahid; Muhammad H.Q. Khan
    The science of chemical taxonomy is used for the classification of plants on the basis of their chemical constituents which are deeply concerned with the molecular characteristics. Five locally available plant taxa of Solanum nigrum Complex viz.: S. americanum Mill., S. chenopodioides Lam., S. nigrum L., S. retroflexum Dunal and S. villosum Mill. were investigated. GC-MS and HPLC were used as the analytical tools to resolve the international taxonomic controversy about these plants. Comparative qualitative and quantitative analyses of these plant samples were undertaken keeping Alkaloids, Flavonoids and Epicuticular wax as potential characters. The glycosides of alkaloids and flavonoids were determined by HPLC whereas their aglycones and epicuticular waxes were analysed using GC-MS. HPLC and GC-MS analyses of these constituents from S. nigrum Complex had not been reported previously. Statistical cluster analyses of results grouped taxa into different clusters on the basis of similarity index and Euclidean distance.
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    Impact of wind farms on birds: a review
    (2012) Mehwish Mujahid; Ayesha Mohy-Ud-Din
    Islam is recognized as a broad approach of life whose teachings cover every likely human relationship including that with the environment. We, human beings, are permitted to employ the earth's resources land, water, air, minerals, flora, fauna, feathered creatures to accommodate our needs, but only in an approach that does not disturb ecological equilibrium and that does not discredit the ability of future generations to meet their needs. Wind farming is a mean of obtaining electric energy that does not produce air toxic wastes, effluence, greenhouse gasses, smog, fumes, litter, trash or other forms of environmental squalor associated with fossil fuel technologies. For a wind farm model, birds may be injured by direct impact with turbine blades, towers and/or transmission lines. This review explains the impact of wind farms on birds with an assessment of the probable bird species/groups that may fabricate problems by wind farm occurrences. It describes a couple of means by which wind farms can possibly have cogent effects on birds. Firstly they can pose a risk of collision, with birds soaring into rotor blades, resulting in increased mortality rates. Secondly they can cause loss of habitat, mainly through movement of birds from an area around the wind turbines. The degree and austerity of all impacts could best be lessened by the careful laying of proposed wind farms and by preparing a site management plan and design through numerous active strategies as explained in the paper