asymmetric membranes are widely used in many industrial membrane separation processes. the major advantage of membrane filtration over the conventional process is its ability to remove a wider spectrum of particles without using any chemicals. hollow fiber configuration offer many advantages over flat-sheet or tubular membranes. the spinning process of hollow fiber may look simple, yet it is te...

a semi-empirical mathematical model for predicting physical part of ignition delay period in the combustion of direct - injection diesel engines with swirl is developed . this model based on a single droplet evaporation model . the governing equations , namely , equations of droplet motion , heat and mass transfer were solved simultaneously using a rung-kutta step by step unmerical method . the...

This study was conducted in a sugar beet field at Collage of Agriculture Experimental Station, Ferdowsi University of Mashhad, Iran. In order to describe the pattern of spatial variations and density of Chenopodium album, Solanum nigrum, Amaranthus sp., Portulaca oleracea, Echinochla crus-galli, and Convulvulus arvense as the main prevalent annual and perennial weeds of sugar beet fields, geost...

the history of plant’s used for mankind is as old as the start of humankind. initially, people used plants for their nutritional proposes but after the discovery of medicinal properties, this natural ?ora became a useful source of disease cure and health improvement across various human communities. berberis vulgaris is one of the medicinal plants used in iranian traditional medicine. berberis ...

in this thesis, a new optically active poly(amide-imide) (pai) was synthesized by the indirect polycondensation reaction of the l-phenylalanine based diacid chloride and 4,4?-diaminodiphenylether in the presence of triethylamine in n-methyl-2-pyrrolidone. the formation of pai was confirmed by ftir, 1h nmr and elemental analysis. in next step, the surface of titanium dioxide (tio2) nanoparticles...

in this thesis a calibration transfer method is used to achieve bilinearity for augmented first order kinetic data. first, the proposed method is investigated using simulated data and next the concept is applied to experimental data. the experimental data consists of spectroscopic monitoring of the first order degradation reaction of carbaryl. this component is used for control of pests in frui...