In this paper the parametric study is carried out to investigate the effect of number of cells in optimal cost of the non-prismatic reinforced concrete (RC) box girder bridges. The variables are geometry of cross section, tapered length, concrete strength and reinforcement of the box girders and slabs that are obtained using ECBO metaheuristic algorithm. The design is based on AASHTO standard s...

in this study, the influence of the salts as an additive on the performance of the membrane was investigated and an extensive work was performed to optimize pvdf hollow fiber membranes through a response surface methodology (rsm). the prepared membranes were characterized by sem, contact angle and lep measurement. then, the rsm was used for the optimization of surface pore size, porosity and hy...

The interaction between the ions and the charge of membranes can affect the efficiency of pollutant removal. The present study investigated the removal efficiency of hexavalent chromium and nitrate ions from both actual and synthetic contaminated water via two different commercial spiral wound polyamide nanofilters. In addition, the interaction of ions under different experimental conditions wa...

chaetomorpha sp is one of the persian gulf green algae which can be a marine source of natural antioxidants such as polyphenols. industrial and economic development of these materials is influenced by effective extraction and application methods. microwave-assisted extraction (mae) and ultrasound-assisted extraction (uae) are novel techniques which have a potential to apply in laboratory with a...

This technical note deals with a priori estimation of efficiency of functional magnetic resonance imaging (fMRI) designs. The efficiency of an estimator is a measure of how reliable it is and depends on error variance (the variance not modeled by explanatory variables in the design matrix) and the design variance (a function of the explanatory variables and the contrast tested). Changes in the ...

Nearly every theory of causal induction assumes that the existence and strength of causal relations needs to be inferred from observational data in the form of covariations. The last few decades have seen much controversy over exactly how covariations license causal conjectures. One consequence of this debate is that causal induction research has taken for granted that covariation information i...

the ultrasound assisted emulsification microextraction (usaeme) method followed byinductively coupled plasma-atomic emission spectrometry (icp-aes) was used for preconcentration anddetermination of bismuth (bi), indium (in) and lead (pb) in the plant azolla filiculoides lam. calix [4] pyrrole was used as a chelating agent and tetrachloroethylene was selected as extraction solvent. the main para...

enhanced oil recovery using nitrogen injection is a commonly applied method for pressuremaintenance in conventional reservoirs. numerical simulations can be practiced for the prediction ofa reservoir performance in the course of injection process; however, a detailed simulation might takeup enormous computer processing time. in such cases, a simple statistical model may be a goodapproach to the...

nanostructured ruo2 powders were synthesized via a hydrothermal method at 180 °c for 12 h using 1 and 2 m naoh aqueous solutions. the structure of the obtained nanomaterials was investigated by powder x-ray diffraction (pxrd) technique. the morphology the obtained materials were studied by field emission scanning electron microscope (fesem). the technique showed that with changing the reaction ...

the ultrasound assisted emulsification microextraction (usaeme) method followed byinductively coupled plasma-atomic emission spectrometry (icp-aes) was used for preconcentration anddetermination of bismuth (bi), indium (in) and lead (pb) in the plant azolla filiculoides lam. calix [4] pyrrole was used as a chelating agent and tetrachloroethylene was selected as extraction solvent. the main para...