background and objectives: psychrotrophic bacteria can produce enzymes at low temperatures; this provides a wide biotechnological potential, and offers numerous economical advantages over the use of mesophilic bacteria. in this study, extracellular protease production by psychrotrophic rheinheimera sp. (km459533) was optimized by the response surface methodology. materials and methods: the cult...

response surface methodology is a common tool in optimizing processes. it mainly concerns situations when there is only one response of interest. however, many designed experiments often involve simultaneous optimization of several quality characteristics. this is called a multiresponse surface optimization problem. a common approach in dealing with these problems is to apply desirability funct...

The present study presents an algorithm that models uncertainties at the structural component level to estimate the performance reliability of RC structures. The method calculates the performance reliability using a systemic approach and incorporates the improved response surface method based on sampling blocks using the first-order reliability method and conditional reliability indices. The re...

esterification of chitosan with adipic acid catalyzed by immobilized candida antarctica lipase b was carried out in this study. response surface methodology (rsm) based on a four-factor- five-level small central composite design (sccd) was employed to model and analyze the reaction. a total of 21 experiments representing different combinations of the four reaction parameters including ch...

vanadium phosphorus oxides (vpo) has been applied as a heterogeneous catalyst in gas phase oxidation reactions and its application is very limited in liquid phase. in this study a series of cobalt-doped vanadium phosphorus oxides (vpo-co) catalysts with different loading of co (0.01-1.0 mol ratio of co/v) were prepared. oxidation of benzyl alcohol was studied in the liquid phase over vpo and vp...

in this paper, size distribution of nano-bubbles was measured by the reliable and fast method of laserdiffraction technique. nano-bubbles were produced using a nano-bubble generator designed and madebased on hydrodynamic cavitation phenomenon in venturi tubes. a central composite design withresponse surface methodology was used to conduct a five factor, five level factorial experimental designo...

introduction: advanced oxidation processes (aops) suggest a highly reactive, nonspecific oxidant namely hydroxyl radical (oh•), that oxidize a wide range of pollutants fast and non-selective in wastewater and water. materials and methods: in this work, the nitrogen-doped titanium dioxide nanoparticles were primed by sol-gel method, characterized by x-ray diffraction and scanning electron micros...

in this present study the dissolved air flotation (daf) system was investigated for the treatment of kermanshah oil refinery wastewater. the effect of three parameters on flotation efficiency including of flow rate (outflow from the flotation tank), saturation pressure and coagulant dosage on chemical oxygen demand (cod) removal was examined experimentally. all the experiments were done under a...

in order to reduce the costs associated with poly-β-hydroxybutyrate production, growth and poly-β-hydroxybutyrate production of ralstonia eutropha were studied in batch culture on different carbon sources. experiments were designed and conducted to not only lower the cost of poly-β-hydroxybutyrate production by using inexpensive substrates, but also to increase poly-β-hydroxybutyrate production...