In this study, molecular dynamics simulation is used to investigate the adsorption of an anticancer drug, doxorubicin, on bundles of functionalized single-walled carbon nanotubes (SWNTs) in an aqueous solution. Carboxylic group has been selected as the functional group. Molecular dynamics (MD) simulations are performed for both separated systems containing a SWNT bundle and a functionalized carbon nanotube bundle, and results are compared with existing experimental data. MD results show that doxorubicin can be adsorbed on CNTs using different methods such as entrapment within CNT bundle, attachment to the side wall of the CNT, and adsorption on the CNT inner cavity. For functionalized CNT, the adsorption of drugs on the functional groups is essential for predicting the enhancement of drug loading on the functionalized nanotubes. Furthermore, the adsorption behavior of doxorubicin on CNTs is fitted with Langmuir and Freundlich isotherm models. The results show that Langmuir model can predict the adsorption behavior of doxorubicin on CNTs more accurately than Freundlich model does. As predicted by this isotherm model, the adsorption process of doxorubicin on CNTs is relatively difficult, but it can be improved by increasing the functional groups on the CNTs surface.

BET surface area and micropore volume are important factors for improving methane storage in activated carbons (ACs). Specification and optimization of carbon structures are vastly examined by different researchers. However, because of complex relations between independent and dependent variables, the proposed statistical and mathematical models are not satisfactory. In this paper, the specifications of some ACs synthesized by chemical activation methods are predicted. The effects of parameters such as agent type, activation time, activation temperature, impregnation ratio and heating rate on the BET surface areas and micropore volumes of ACs are also analyzed. Two models of artificial neural networks and adaptive neuro-fuzzy interference systems are used. Later on, a number of data on other ACs reported by several researchers are used for the model validation. The obtained results from these two models are found to be satisfactory. The coefficients of determination for these models were 0.982 and 0.984, respectively. Through this modelling of AC production process, which was the main purpose of this study, the specifications of ACs may be obtained without spending extra time and expenses.

In this paper, simulation of InAs/GaAs quantum dot (QD) laser is performed based upon a set of eight rate equations for the carriers and photons in five energy states. Carrier dynamics in these lasers were under analysis and the rate equations are solved using 4th order Runge-Kutta method. We have shown that by increasing injected current to the active medium of laser, switching-on and stability time of the system would decrease and power peak and stationary power will be increased. Also, emission in any state will start when the lower state is saturated and remain steady. The results including P-I characteristic curve for the ground state (GS), first excited state (ES1), second excited state (ES2) and output power of the QD laser will be presented.