Journal of Multiscale Modelling

The present study deals with both experimental and numerical investigation on vibration behavior of laminated composite plates subjected to varying temperature and moisture. Extensive experiments are carried out for free vibration analysis of woven fiber Glass/Epoxy composite plates under hygrothermal conditions. The specimens were hygrothermally conditioned in a humidity cabinet where the conditions were maintained at high temperatures and moisture concentrations.

Calcium plays a significant role in a number of processes like muscle contraction, gene expression, synaptic plasticity, signal transduction etc. but the significance of calcium oscillation is not yet completely understood in most of the cell types. A number of investigators have reported the oscillatory behavior of calcium due to intracellular concentration of inositol 1,4,5-trisphosphate (IP₃). In this paper, an attempt has been made to study the oscillations induced in calcium due to dynamically changing membrane potential with special relevance to sodium pump. A mathematical model is developed which incorporates nearly all important and necessary biophysical components like L-type calcium channel, sodium channel, potassium channel, cytosolic buffers, calcium pump, sodium–calcium exchanger (NCX), sodium–potassium ATPase (sodium pump), and dynamic membrane potential. These channels have realistic gating mechanism and emulate the gating mechanism proposed in the famous paper of Hodgkin and Huxley.¹ The model leads to an initial value problem involving system of non-linear ordinary differential equations. A numerical solution has been obtained using Gear's method. The numerical results have been used to study the effect of sodium pump over the frequency of Ca²⁺ oscillation. At lower and higher sodium pump current densities the Ca²⁺ oscillation frequency is observed to be 278 Hz and 225 Hz respectively.

In this paper, we anatomized transport properties of butane belonging to the saturated alkane group (C_nH_2n+2) using three terminal anchor elements (nitrogen, oxygen and sulfur) in Trans configuration connected to gold electrodes, forming a two probe model. The transport properties of three variants of butane were investigated in terms of Transmission spectra, Eigenstates, I-V characteristics and differential conductance for different values of biasing voltage using Keldysh's non-equilibrium Green's function combined with semi-empirical extended Hückel theory. Amongst the three binding elements, Butane exhibited maximum charge transfer with sulfur, then with nitrogen and least with oxygen. The HOMO-LUMO gap for both nitrogen and Oxygen as terminal anchoring elements suggested that conduction was virtually impossible through Butane in particular cases. Nature of Ballistic current for butane anchored with sulfur is ideal for its applicability as nano-diode or resonant tunneling diodes (RTDs) in arena of quantum-electronics due to its strong coupling between the terminal atoms and carbon atoms of butane. The retrenching order obtained in terms of conductance is S > N > O anchored butane molecule which seemed in full confirmation with the results of Transmission spectrum and its Eigenstates and proved sulfur to be a promising binding element and can produce much better results in comparison to oxygen and nitrogen. This paper marked another step in the field of molecular electronics as the butane anchored with sulfur has characteristics in conjunction to the semiconductor junction diode.

In this study, the influence of porosity on the elastic effective properties of polycrystalline materials is investigated using a 3D grain boundary micro mechanical model. The volume fraction of pores, their size and distribution can be varied to better simulate the response of real porous materials. The formulation is built on a boundary integral representation of the elastic problem for the grains, which are modeled as 3D linearly elastic orthotropic domains with arbitrary spatial orientation. The artificial polycrystalline morphology is represented using 3D Voronoi Tessellations. The formulation is expressed in terms of intergranular fields, namely displacements and tractions that play an important role in polycrystalline micromechanics. The continuity of the aggregate is enforced through suitable intergranular conditions. The effective material properties are obtained through material homogenization, computing the volume averages of micro-strains and stresses and taking the ensemble average over a certain number of microstructural samples. The obtained results show the capability of the model to assess the macroscopic effects of porosity.