in this research, rice husk and activated carbon adsorbents were used for removal of lead ion from aqueous solution at ph= 6. in the batch tests experimental parameters were studied, including contact time and initial metal ions concentration.survey of the equilibrium time at different concentration showed that equilibrium time is reduced with decrease of initial concentration of solution from ...

In this paper, the Bertrand's price competition in the retail duopoly with asymmetric costs is analyzed. Retailers sell substitute products in the framework of the classical economic order quantity (EOQ) model with linear demand function. The market potential and competitor price are considered to be the bifurcation parameters of retailers. Levels of the barriers to market penetration depending...

This research presents adsorption potential of surfactant (sodium dodecyl sulphate; SDS) coated magnetite nanoparticles as suitable and efficient adsorbent for the removal of Basic Blue 41 (BB 41), as a cationic dye from textile’s company wastewater. The effects of various experimental parameters (e.g. initial pH of the solution, SDS amount, and ionic strength) on the adsorption efficiency of B...

Fine particles Silicoaluminophosphate-34 were synthesized by hydrothermal sol-gel method. The effect of crystallization time, as one of the important synthesis factors on particle size and crystallinity, kinetic and equilibrium adsorption, and selectivity of CO2 / CH4 has been studied in this work. The adsorption isotherms are obtained at mod...

Hydroxyapatite nanocrystals were synthesized by sol-gel combustion method for the sorption ofHg(II) ions from aqueous solutions. The effects of varying parameters such as pH, temperature, initialmetal concentration, and contact time on the adsorption process were examined. Adsorptionequilibrium was established in 360 minutes and the maximum adsorption of Hg(II) on thehydroxyapatite was observed...

This paper introduces a methodology for soil slope stability analysis based on optimization, limit equilibrium principles and method of slices. In this study, the slope stability analysis problem is transformed into a constrained nonlinear optimization problem. To solve that, a Self-Adaptive Genetic Algorithm (GA) is utilized. In this study, the slope stability safety factors are the objective ...

To determine the maximum equilibrium prevalence of mosquito-borne microparasitic infections, this paper proposes a general model for vector-borne infections which is flexible enough to comprise the dynamics of a great number of the known diseases transmitted by arthropods. From equilibrium analysis, we determined the number of infected vectors as an explicit function of the model's parameters a...

What is the best description that we can construct of a thermodynamic system that is not in equilibrium, given only one, or a few, extra parameters over and above those needed for a description of the same system at equilibrium? Here, we argue the most appropriate additional parameter is the nonequilibrium entropy of the system. Moreover, we should not attempt to estimate the probability distri...

In this study, a limit equilibrium method has been developed that satisfies all conditions of equilibrium and assumes circular slip surfaces. All force and moment equilibrium equations are employed without using simplification assumptions. A non-linear optimization technique is used to solve the system of equations with the corresponding constraints. The proposed method is capable to determine ...