Accuracy of the Adomian decomposition method applied to the Lorenz system

In this paper, the Adomian decomposition method (ADM) is applied to the famous Lorenz system. The ADM yields an analytical solution in terms of a rapidly convergent infinite power series with easily computable terms. Comparisons between the decomposition solutions and the fourth-order Runge–Kutta (RK4) numerical solutions are made for various time steps. In particular we look at the accuracy of the ADM as the Lorenz system changes from a non-chaotic system to a chaotic one.     

Solving systems of ODEs by homotopy analysis method

This paper applies the homotopy analysis method (HAM) to systems of ordinary differential equations (ODEs). The systems investigated include stiff systems, the chaotic Genesio system and the matrix Riccati-type differential equation. The HAM gives approximate analytical solutions which are of comparable accuracy to the seven- and eight-order Runge–Kutta method (RK78).     

Solution of fully developed free convection of a micropolar fluid in a vertical channel by homotopy analysis method

In this paper, we reconsider the problem of fully developed natural convection heat and mass transfer of a micropolar fluid in a vertical channel with asymmetric wall temperatures and concentrations. The resulting boundary‐value problem is solved analytically by the homotopy analysis method. The accuracy of the present solution is found to be in excellent agreement with the solutions of Cheng (Int. Commun. Heat Mass Transfer 2006; 33 :627–635). Copyright © 2008 John Wiley & Sons, Ltd.     

Photoelectric studies of gallium monosulfide single crystals

Photoconductivity (PC) studies were carried out on GaS single crystals prepared from melt by directional solidification. We studied the effect of light intensity, applied voltage on both the PC and the lifetime of carriers. The V-I characteristics and the absorption spectra were checked for different sample thickness. The present investigation was extended to study the spectral distribution of the photocurrent for GaS. It was found that the photocurrent curves are practically independent of the bias voltage. The energy gap for GaS was found to be 2.5 eV.     

从光子晶体效应到表面等离子波的实时演变

文章报道了激光诱导太赫兹表面等离子谐振效应。采用激光抽运-太赫兹波探测技术，实时改变单晶硅中的载流子浓度，使其介电特性从类绝缘体演变为类金属导体，以支持表面等离子谐振效应，进而实现太赫兹波在周期性亚波长单晶硅孔阵列中的实时可控制谐振增强传输。同时还通过实验观测到太赫兹波从光子晶体效应到表面等离子波的实时演变。文章作者采用Fano模型对实验结果进行模拟分析，获得了与实验数据一致的理论拟合。     

Performance analysis of wick-assisted heat pipe solar collector and comparison with experimental results

The performance of heat pipe solar collector is investigated theoretically and experimentally. The system employs wick-assisted heat pipe for the heat transfer from the absorber (evaporator) to a heat exchanger (condenser). The heat pipe is made with a copper tube and the evaporator section is finned with aluminium plate. Theoretical model predicts the outlet water from heat exchanger, heat pipe temperature and also the thermal efficiency of solar collector. The results are compared with experimental data.     

Preferred design of recurrent neural network architecture using a multiobjective evolutionary algorithm with un-supervised information recruitment: a paradigm for modeling shape memory alloy actuators

Shape memory alloys (SMAs) are able to compensate any undergoing plastic deformations and return to their memorized shape. Such a behavior persuades industrialists to use them for different engineering applications, as smart actuators and sensors. Because of their vast applications, it is crucial to engineers to develop effective identification tools capable of simulating the behavior of SMAs. However, SMA actuators have complex and hysteric behavior that in turn obstructs the modeling process. The motivation behind the current study emanates in the pursuit of developing efficient prediction tools for effective modeling of SMA actuators. Actually, after several experiments and software simulations, the authors develop a hybrid intelligent tool which takes advantage of the self-organizing Pareto based evolutionary algorithm (SOPEA) and simultaneous recurrent neural network (SRNN), as a black-box model, to automatically identify the behavior of SMA. SOPEA is a multiobjective evolutionary algorithm which is based on the concepts of survival of the fittest, non-dominated sorting and information recruitment. The information recruitment is guaranteed by applying an un-supervised neuro computing technique, i.e. adaptive self organizing map (ASOM) with conscience mechanism. ASOM is an un-supervised network that assists SOPEA to recognize the non-dominated patterns and produce further non-dominated solutions. Together with the structure of SOPEA, the authors follow a comprehensive preference-based strategy to exploit the desired regions in the Pareto front. This occurs through introducing deliberate reference points. The outcome method is applied to the design of SRNN for modeling the SMA actuator. It is demonstrated that the designed optimization tool can show acceptable performance for the present case study within the imposed computational budget. Besides, through a rigorous experimental procedure, it is indicated that by applying an efficient artificial system, the behavior of SMA can be identified without any specific knowledge of the physical conditions and governing equations.     

Zinc oxide nanorod‐loaded activated carbon for ultrasound‐assisted adsorption of safranin O: Central composite design and genetic algorithm optimization

This paper focuses on the development of an effective methodology to obtain the optimum ultrasonic‐assisted removal of a dye, safranin O (SO), under optimum conditions that maximize the removal percentage, using ZnO nanorod‐loaded activated carbon (ZnO‐NRs‐AC) in aqueous solution. Central composite design coupled with genetic algorithm was used for parameter optimization. The effects of variables such as pH, initial dye concentration, mass of ZnO‐NRs‐AC and sonication time were studied. The interactive and main effects of these variables were evaluated using analysis of variance. The structural and physicochemical properties of the ZnO‐NRs‐AC adsorbent were investigated using field emission scanning electron microscopy and X‐ray diffraction. Adsorption equilibrium data were fitted well with the Langmuir isotherm and the maximum monolayer capacity was found to be 32.06 mg g^?1. Studies of the adsorption kinetics of the SO dye showed a rapid sorption dynamic with a ^pseudo‐second‐order kinetic model, suggesting a chemisorption mechanism.     

Analysis of a Drop-Push Model for Percolation and Coagulation

In this article, we study a type of a one dimensional percolation and coagulation model whose basic features include a sequential dropping of particles on a substrate followed by their transport via a pushing mechanism. Particles are dropped onto a one dimensional lattice and carry out a random walk until they encounter an empty site where they become stuck. In such a model, calculating the probability of coalescence of two arbitrary clusters of particles, we embed a certain coalescence process, called the additive Marcus-Lushnikov process, which converges to a particular solution of the Smoluchowski equation. Throughout, we study the asymptotic behavior of the arrangement of empty sites and of the total displacement of all particles as well as the partial displacement of some particles, when the number of sites and of the particles tend to infinite.