compressible gas flow inside a convergent-divergent nozzle and its exhaust plume atdifferent nozzle pressure ratios (npr) have been numerically studied with severalturbulence models. the numerical results reveal that, the sst k–ω model give the bestresults compared with other models in time and accuracy. the effect of changes in value ofdivergence half-angle (ε ) on the nozzle performance, thru...

Problem statement: The extraction of lipids from microalgae for biofuel production is a significant problem due to the intractability of their cell wall. The aim of this study of lipid extraction from Nannochloropsis microalgae was to examine the relative efficiencies of some commonly used solvent systems and test the use of co-boiling solvents in Soxhlet extraction as an improved method. Appro...

We investigate Li+ coordination in mixed electrolytes based on ionic liquids (ILs) and organic solvents and its relation with the macroscopic properties such as phase behaviour and ionic conductivity. Using Raman spectroscopy we determine the solvation shell around Li+ in mixtures formed by the IL N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide, the organic solvents ethylene ca...

Using the mixed solvents, (water +ethanol + propanol), the solubility of CdF2 was determined byevaporating method at 25° C. The results showed that the sollbility, s, of CdF2 decreases bydecreasing the dielectric constant of the mixed solvent .Once the solubility of CdF2 was determined,the concentration solubility product, Ksp(c)=4s3, was calculated .Furthermore ,by estimating the meanactivity ...

The electric and optical properties of molecules are commonly investigated by measurements of their absorption and fluorescence spectra, both in pure solvents of different polarities [1] and in mixed solvents [2]. The molecules benzophenone (BF), 2-aminobenzophenone (2ABF) and 4-aminobenzophenone (4ABF) investigated in this paper show no fluorescence at room temperature. Their absorption spectr...

Using the Jagla model potential we calculate the potential of mean force (PMF) between hard sphere solutes immersed in a liquid displaying water-like properties. Consistent estimates of the PMF are obtained by (a) umbrella sampling, (b) calculating the work done by the mean force acting on the hard spheres as a function of their separation, and (c) determining the position dependent chemical po...

The aggregation and interfacial behavior of mixtures of anionic (sodium dodecylsulfate, SDS) and cationic (dodecylammonium bromide, DTAB) surfactants were investigated. A room-temperature ionic liquid (IL) was explored as a solvent for the SDS/DTAB system and compared to water. The critical micelle concentration (cmc) and composition in mixed micelles were determined for both solvents. Our expe...

1,3-Butadiene, BD is produced from C4-cut by extractive distillation. The separation of 1,3-Butadiene from C4-cut is not possible through the conventional distillation processes, because several mixtures have consisted of close boiling points constituents and make azeotrope. The BASF extraction distillation process in BD unit of Jam and Amirkabir Petrochemical Company improves the relative vola...