a chemically modified carbon paste electrode with multiwall carbon nanotube (mwcnt) was prepared and used as a sensor for cu2+ ion. the unique chemical and physical properties of cnt have paved the way  to  new  and  improved  sensing  devices.  a  central  composite chemometrics  design  was  applied  for  multivariate  optimization  of the  effects  of  three  significant  parameters  (graphi...

considering the increasingly high attention to quality, promoting the reliability of products during designing process has gained significant importance. in this study, we consider one of the current models of the reliability science and propose a non-linear programming model for redundancy allocation in the series-parallel systems according to the redundancy strategy and considering the assump...

in this research, a rapid, reliable and selective dispersive liquid-liquid microextraction (dllme) followed by direct injection of microdroplet to graphite furnace atomic absorption spectrometry (gf-aas) method for the determination of ultra-trace amounts of ag(i) was developed. effect of the important experimental parameters on the extraction efficiency of ag(i) was investigated using response...

background and objective: glucoamylase is a potent starch degrading enzyme whose cheap production has been an area of research. its production by aspergillus niger in solid-state fermentation was studied using dried garden pea peel as a substrate, which enormously reduced the production cost. the current study intended to produce glucoamylase by a cost-effective strategy and exhaustively charac...

tannase has several important applications in food, feed, chemical and pharmaceutical industries. in the present study, production of tannase by mutant strain, penicillium sp. ez-zh390, was optimized in submerged fermentation utilizing two statistical approaches. at first step, a one factor at a time design was employed to screen the preferable nutriments (carbon and nitrogen sources of the med...

incorporation of functional foods and nutraceuticals such as carotenoids which suffer from poor water solubility and low bioavailability into nano-sized delivery systems can improve their solubility, stability and oral bioavailability. the aim of this study was to prepare β-carotene nanodispersion and investigate the effects of preparation parameters by means of response surface methodology usi...

conclusions we found ccd and rsm very effective in optimizing hib culture conditions, and hib biomass production was greatly influenced by ph and incubation temperature. therefore, optimization of the growth factors to maximize hib production can lead to 1) an increase in bacterial biomass and prp productions, 2) lower vaccine prices, 3) vaccination of more susceptible populations, and 4) lower...

in design of experiments, analysis and identifying those variables that affect the outputs are of interest. response surface methodology is a mathematical-statistical method to optimize the experiment outputs. this method tries to find the best response levels by optimizing the design variables called factors. in many engineering applications, robust design has become the most important issues....

conclusions the results of this study show that it is possible to remove nitrate, and its intermediates from waste water. regarding the desirability of the process, the field scale study is proposed. results the results showed that by applying electric current of 0.14 a for 120 minutes, the nitrate content would reduce down to 97%. the obtained r2 for the nitrate removal model was higher than 0...