In this work, some strategies and methods, based on finite-difference schemes, are introduced to model the propagation of acoustic waves in a three-dimensional fluid-solid configuration. Specifically, we have considered a heterogeneous propagation medium placed inside a 3D rectangular volume. A plane interface separates the volume into two regions: the first region is a fluid and the second one...

We consider the scattering of time harmonic electromagnetic plane waves by a bounded, inhomogeneous, anisotropic dielectric medium and show that under certain assumptions a lower bound on the norm of the (matrix) index of refraction can be obtained from a knowledge of the smallest transmission eigenvalue corresponding to the medium. Numerical examples are given showing the efficaciousness of ou...

several strains of saccharomyces cerevisiae were isolated from different sources. these strains were under taken for ethanol tolerance analysis and growth under stress condition. exponential phase to various concentrations of ethanol (2–26% v/v) for 1 h was used for isolation of resistant strains. viable cells were isolated and purified by inoculation of diluted samples on yeast extract peptone...

cyanobacteria were collected and identified in five paddy fields with different soil textures of golestan province in iran. it was determined that nostoc ellipsosporum and nostoc muscorum were dominant in all sites among 20 species. to assess the ability of atmospheric nitrogen fixation by the species, their pure cultures were provided by growing on bg-11 solid culture medium. subsequently, eac...

Optimization of the fermentation medium for maximum alkaline protease production was carried out. Fifteen positive isolates were examined for their extent of alkaline protease production. The most potent producer was identified as Bacillus sp. The solid substrate screening showed that the combination of wheat straw and bean husk was the best one. The initial screening by using Plackett–Burman’s...

An experimental study was conducted to determine the effects of the leaching parameters on impurity ion concentrations of the liquid phase in ulexite leaching. Powdered ulexite ore was leached in an aqueous medium with sulfur dioxide. The Taguchi experimental design approach and statistical methods were used to evaluate the effects of the leaching parameters (solid/liquid ratio, temperature...

Pipelines transporting solid-liquid mixtures are of practical interest to the oil and pipe industry throughout the world. Such pipelines are known as slurry pipelines where the solid medium of the flow is commonly known as slurry. The optimal designing of such pipelines is of commercial interests for their widespread acceptance. A methodology has been evolved for the optimal sizing of a pipelin...

Steady state natural convection of Al2O3-water nanofluid inside a square cavity filled with a porous medium is investigated numerically. The temperatures of the two side walls of the cavity are maintained at TH and TC, where TC has been considered as the reference condition. The top and the bottom horizontal walls have been considered to be insulated i.e., non-conducting and impermeable to mass...