نتایج جستجو برای: known drawbacks and advantages
تعداد نتایج: 16845649 فیلتر نتایج به سال:
Global air pollution is a serious threat caused by excessive use of fossil fuels for transportation. Despite the fact that diesel fuel is a big environmental pollutant as it contains different hydrocarbons, sulphur and crude oil residues, it is yet regarded as a highly critical fuel due to its wide applications. Nowadays, biodiesel as a renewable additive is blended with diesel fuel to achie...
The contents of total ashes and ethanol soluble substances were determined for propolis samples from species two Meliponini genera: Melipona Scaptotrigona. All corresponded to geopropolis (propolis containing aggregated soil material), with ash above 40%. Only one Scaptotrigona was shown produce geopropolis, but content (12%) much lower than samples. In a high negative correlation observed betw...
the space now known as complete erdos space ec was introduced by paul erdos in 1940 as the closed subspace of the hilbert space ?2 consisting of all vectors such that every coordinate is in the convergent sequence {0} ? { 1 n : n ? n}. in a solution to a problem posed by lex g. oversteegen we present simple and useful topological characterizations of ec. as an application we determine the ...
Abstract: The big share of electrical breakdown in electrical devices failure among other factors is caused by multitasking such as electrical insulation, mechanical support, energy dissipation, Energy storage, etc. which brings many attentions to lifetime estimation of said insulation material. Up to now, there was no-general theory had been suggested for lifetime estimation of mentioned insul...
abstract: in this thesis, we focus to class of convex optimization problem whose objective function is given as a linear function and a convex function of a linear transformation of the decision variables and whose feasible region is a polytope. we show that there exists an optimal solution to this class of problems on a face of the constraint polytope of feasible region. based on this, we dev...
titanium and its alloy are known as important load-bearing biomaterials. the major drawbacks of these metals are fibrous formation and low corrosion rate after implantation. the surface modification of biomedical implants through various methods such as plasma spray improves their osseointegration and clinical lifetime. different materials have been already used as coatings on biomedical implan...
Considering the drawbacks associated with fossil-based molecules, polymers and materials, lignin has acquired immense popularity owing to its distinct advantages. However, date it not been w...
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