in this study, porous scaffolds from poly(d,l-lactic acid) have been prepared via liquid- liquid phase separation method in ternary system of polymer-1,4-dioxane-water. polymer dissolved in dioxane in 1.5, 2.5 and 5 % wt/v and the solvent/non-solvent ratios were 13/87, 15/85 and 17/83. cloud point curves prepared by visual turbidometry. in order to obtain porous scaffolds with inter-connected p...

in this research mass transfer coefficient under jetting regime in different directions (from dispersed to continuous and continuous to dispersed phase) has been studied using an experimental setup. n-butanol-succinic acid-water with low interfacial tension has been selected as experimental chemical system. the effects of various parameters such as jet velocity, nozzle diameter and the height o...

phase inversion in liquid-liquid dispersions corresponds to the transitional boundary between oil-in-aqueous dispersion and aqueous-in-oil dispersion. a theoretical model based on simple assumptions was proposed to predict phase inversion point, ambivalence region and the hysteresis effect of inversion. experimental data from the literature were used to validate the model and results were compa...

effects of temperature and percentage of organic modifier were studied on retention and selectivity in rp-hplc using solvation parameter model. the system constants were determined by multiple linear regression analysis from experimental values in the retention factor for a group of different solutes with known descriptors by computer using the program spss/pc. the experimental results showed t...

effects of temperature and percentage of organic modifier were studied on retention and selectivity in rp-hplc using solvation parameter model. the system constants were determined by multiple linear regression analysis from experimental values in the retention factor for a group of different solutes with known descriptors by computer using the program spss/pc. the experimental results showed t...

since solid-phase and liquid-phase microextraction (spme and lpme) were introduced, as effective solvent-free methods, many efforts have been made to improve their modes and applications. however, due to limitations with sensitivity and efficiency, researchers have focused on improving the performance of their basic primary modes. in this way, in recent years, different methods such as ultrason...

the determination region of solubility of methanol with gasoline of high aromatic content was investigated experimentally at temperature of 288.2 k. a type 1 liquid-liquid phase diagram was obtained for this ternary system. these results were correlated simultaneously by the uniquac model. the values of the interaction parameters between each pair of components in the system were obtained for t...

the applicability of hollow fiber-based liquid phase microextraction (hf-lpme) was evaluated for the extraction and preconcentration of loratadine prior to determination by hplc. in order to obtain high extraction recovery, the parameters affecting the hf-lpme including type of organic phase, ph of the source and receiving phases, stirring rate, extraction time and salt addition were studied an...

diosmin and hesperidin are natural flavonoid glycosides found in various plant materials, mainly in citrus fruits in different concentrations. diosmin for pharmaceutical use is obtained mainly semi-synthetically from hesperidin. hesperidin often accompanies diosmin as a natural impurity in different pharmaceutical formulations; therefore, a simple, fast and precise method for the simultaneous a...