Cadmium is a hazardous non-biodegradable material that enters the food chain. In this study, the removal of cadmium from aqueous solutions by Canola residues (a natural biosorbent) was investigated. The effect of parameters such as contact time, pH, cadmium concentration and adsorbent dose were evaluated, the results showed that increasing of pH, and contact time and adsorbent caused increasing of efficiency of removal cadmium from aqueous solutions. A comparison between non-linear and linear of estimating the isotherm and kinetic parameters was discussed. The results confirmed that the non-linear method was a more efficient method to gain isotherm and kinetic parameters.

In the present study, we have investigated the external free convection of a nanofluid near a vertical heated surface embedded in a saturated porous medium using the thermal non - Equilibrium assumption. The vertical surface has a linear temperature distribution with a uniform mass suction or injection. Assuming the Brownian motion and thermophoresis as the primary driving mechanisms of free convection of the nanofluid, suitable volume averaged equations are employed. We have also followed similarity solution method for transforming the governing equations in to the ordinary differential equations. The new set of ordinary equations is solved numerically by the Shooting method and the flow and temperature fields are determined completely. The obtained numerical results are employed for calculating the Nusselt numbers for both the solid and liquid phases in the physical domain. Moreover, the Sherwood number for the nanoparticles is determined over a wide range of parameters.

Non-cooperative intelligent control agents (ICAs) with dedicated cost functions, can lead the system to poor performance and in some cases, closed-loop instability. A robust solution to this challenge is to place the ICAs at the feedback Nash Equilibrium point (FNEP) of the differential game between them. This paper introduces the designation of a robust decentralized infinite horizon LQR control system based on the FNEP for a linear time-invariant system. For this purpose, two control strategies are defined. The first one is a centralized infinite horizon LQR (CIHLQR) problem (i.e. a supervisory problem), and the second one is a decentralized control problem (i.e. an infinite horizon linear-quadratic differential game). Then, while examining the optimal solution of each of the above strategies on the performance of the other, the necessary and sufficient conditions for the equivalence of the two problems are presented. In the absence of the conditions, by using the least-squares error criterion, an approximated CIHLQR controller is presented. It is shown that the theorems could be extended from a two-agent control system to a multi-agent system. Finally, the results are evaluated using the simulation results of a Two-Area non-reheat power system.

Equilibrium calculations of H2S-CO2-alkanolamine solutions (MEA, DEA, DGA, MDEA and DIPA) are performed using. the Gibbs free energy minimization. Two equations for chemical potential as a function of temperature mid loading for amine and its carbamate derivative are proposed and their coefficients are determined and reported. Partial pressures of H2S, CO2 over alkanolamine solutions are predicted and compared with experimental data and also with the modified Kent-Eisenberg model. Overall, the accuracy of the model is good and, in some cases, better results than those of the modified Kent-Eisenberg model sire obtained.

Sawdust of Triplochiton Scleroxylon was evaluated as a new biosorbent of heavy metals. On contacting 100mgL-l copper (II) solutions with 20 g L-1 Sawdust, during shake flask contact time of 45 min, the metal removal was noted to be 69%. The influence of pH, sorbent dose, concentration, temperature, and contact time on the sorption of Cu (II) on sawdust has been studied by batch process. The optimum conditions of sorption were found to be: contact time of 45 min, pH and temperature 4.0 and 40oC respectively. The sorption kinetics was found to follow pseudo-second-order model. The sorption data perfectly fit the linear Langmuir isotherm model with 0.99 regression coefficient (R2) and 0.66 average percentage errors (e%). The fit on Freundlich adsorption isotherm model was acceptable but not as good. Calculated thermodynamic parameters such as DHo, DSo and DGo indicated spontaneous and exothermic nature of the process. The study points out the potential use of sawdust; at present has no commercial value, for the treatment of wastewaters contaminated with heavy metals.