formaldehyde in small quantities is commonly analyzed by spectrophotometric methods. one of the most-commonly used spectrophotometric techniques for this purpose is based on the reaction with chromotropic acid. because of its simplicity, sensitivity, selectivity and its low cost, it is still widely used. investigations for replacing the concentrated sulfuric acid with other acids or using more ...

a box-behnken design with three replicates was used for preparation and evaluation of eudragit vancomycin (vcm) nanoparticles prepared by double emulsion. the purpose of this work was to optimize vcm nanoparticles to improve the physicochemical properties. nanoparticles were formed by using w1/o/w2 double-emulsion solvent evaporation method using eudragit rs as a retardant material. full factor...

a rhamnolipid–type biosurfactant production by pseudomonas aeruginosa mm1011 was studied in a miniaturized shaken bioreactor. the operational parameters, affecting the biosurfactant production in shaken bioreactors, such as shaking frequency (200, 250, 300 rpm), filling volume (50, 75, 100 ml), and aeration rate (0.2, 0.6, 1 vvm), were optimized using response surface methodology. the optimizat...

in this study fullerene functionalized using oleum (h2so4·so3), followed by the hydrolysis of the intermediate cyclosulfated fullerene as well as  an oxidizing agent was employed to functionalize the fullerenes. ruthenium was then added by the impregnation method or deposited on the functionalized fullerene. subsequent to this step, response surface methodology (rsm) was used to study the cumul...

in this work, hydrochloric acid is used to remove iron impurities in the bauxite ore contained in the diasporite mineral located in the sari region. the bauxite ore was calcined at different temperatures and times, and then dissolved in a hydrochloric acid solution. after determining the optimum calcination conditions in 1 h at 900 °c, the response surface methodology (rsm) with four factors in...

Liquid sloshing is a common phenomenon in the transporting of liquid tanks. Liquid waves lead to fluctuating forces on the tank wall. If these fluctuations are not predicted or controlled, they can lead to large forces and momentum. Baffles can control liquid sloshing fluctuations. One numerical method, widely used to model the liquid sloshing phenomena is Smoothed Particle Hydrodynamics (SPH)....

production of several yeast products occur in presence of mixtures of monosaccharides. to study effect of xylose and glucose mixtures with system aeration and nitrogen source as the other two operative variables on xylitol production by pichia guilliermondii, the present work was defined. artificial neural network (ann) strategy was used to athematically show interplay between these three contr...

a hydrothermal method for preparation of nano-size zirconia has been studied to optimize the effective parameters (precursor concentration, temperature and time) using response surface methodology (rsm). the synthesized zirconia samples were characterized through x-ray diffraction (xrd), scanning electron microscope (sem) and transmission electron microscopy (tem) analyses to identify mean nano...

the effect of dry material, glycerol and ratio of water to seed in alyssum homalocarpum films on their thickness, transparency, moisture content, tensile strength, elongation and water vapor permeability was investigated using mixture response surface methods. dry material and glycerol were important factors influencing tensile strength, elongation and water vapor permeability. ratio of water t...