Volume 2 Issue 3
Authors: Bimola Huidrom; N. Rajmuhon Singh
Abstract: Neodymium(III) with L(-) asparagine(monohydrate) complexes in binary and ternary organic solvent mixtures had been spectrophotometrically and thermodynamically investigated. The observed spectra in the visible and near IR-region had been analyzed to calculate interelectronic repulsion parameterSlater-Condon (Fk), Lande spin-orbit coupling constant (ξ4f), covalency parameters (β, b½ and δ) and intensity parameters such as oscillator strengths (P) and Judd-Ofelt parameters (T). The degree of covalency in the complexes increases with increase in oscillator strength values. The hypersensitive band (4I9/2→4G5/2) was correlated with the one of the most intense band of pseudo-hypersensitive i.e., 4I9/2 →4F5/2 transition band to determine the degree of sensitivity of ligand and solvent environment on the complexation. The higher values of covalency parameters and oscillator strength are taken as evidence of participation of f-orbitals in bonding. The positive values of standard enthalpy (H°) and standard entropy (S°) confirmed the endothermic nature and the increasing randomness respectively. The negative values of standard free energy (G°) favours the formation of neodymium (III) with L(-) asparagine(monohydrate) complex in the solution.
Keywords: Neodymium(III); L(-) Asparagine(monohydrate); Hypersensitive; Pseudo-hypersensitive
Authors: Hien Dinh Sy
Abstract: We have developed NEMO-VN2, a quantum device modeling tool that simulates a wide variety of quantum devices including the resonant tunneling diode, the single electron transistor, the molecular field effect transistor, the carbon nanotube field effect transistor. In the simulator the non-equilibrium Green’s function is used to perform a comprehensive study of emerging nanoelectronics devices. The program has been written by using graphic user interface of Matlab. NEMO-VN2 uses Matlab to solve Schrodinger equation with Poisson equation to get current-voltage characteristics of quantum devices. In the report, we describe the upgraded simulator, provide a short overview of the theoretical methodology using nonequilibrium Green’s function for modeling of nanoscale devices and typical simulations related to spin field effect transistor and graphene field effect transistor used to illustrate the capabilities of the NEMO-VN2.
Keywords: Spin Transistor; Spin Field Effect Transistor; Graphene; Graphene Field Effect Transistor; Current; Voltage Characteristics
Authors: Yao Ji-quan; Zhao Shu-qiang; Zhang Er-geng
Abstract: In order to study the failure cause of the wear and breakage of coating cutters, model of coating cutter is built by the Pro/ Engineer, and model file is imported into Ansys software so as to carry out the post-processing by the finite element, and subsequently mechanics, thermal and kinetic analysis of coating cutters are conducted. The failure reasons of coating cutters are also discussed which has certain reference value on the rapid development and to improve the durability for the coating tools.
Keywords: Coating Cutter; Finite Element; Wear; Breakage; PVD
Authors: Muthukumaram Packirisamy; Vo-Van Truong; Simona Badilescu; Mohammed Alsawafta
Abstract: Gold crystals of various morphologies have been produced by evaporating under controlled temperatures asolution of the gold-poly (vinyl alcohol) nanocomposite having entrapped hydrogen bubbles. Three-dimensional structures as well as two-dimensional dendritic gold nanostructures are formed on the different areas of the nanocomposite films. It is thought that the multitude of morphologiesis may be associated to the presence of bubbles of various shapes,entrapped under the surface of the polymer films and distorted by the confinement created by the drying films. The bubbles, through the intermediary of the over layer of poly (vinyl alcohol) film, may act as templates, providing preferential sites for nucleation of gold, confined in more and more reduced volumes, as the evaporation of the solvent advances. It is shown that the degree of super saturation of the solution, mediated by temperature, is one of the parameters determining the morphology of the growing crystals. The procedure holds promise as a new approach for the preparation of shaped gold nanoparticles.
Keywords: Bubbles; Gold Crystals; Shape Control; Templating Methods; Au-PVA Nanocomposite
Authors: Mozhgan Shahamirian; Salma Zamirian
Abstract: The concept of nanoscale reinforcement provides opportunity for synthesis of polymer materials with unique properties. Behaviors of EVA nanocomposites containing nanofillers, such as nanoclay (Cloisite®30B) were investigated. Samples were prepared with the nanoclay content 1, 3 and 5 wt % and their mechanical properties such as tensile strength, tensile modulus have been considered. So O2 permeablity and optical transparency test have also been done. Wide Angle X-Ray Diffraction (WAXD) and Transmission Electron Microscopy (TEM) were in support of the formation of partially delaminated nanocomposite material. TEM images confirmed that the nanocomposites possessed a high level homogeneity resulted from a sufficient dispersion of nanoparticles in the resin matrix. The results also indicated that tensile test of the nanocomposites was significantly influenced by the VA content. O2 Permeability decreases with increasing clay. Also optical transparency is seen that one sample has the maximum haze and minimum gloss.
Keywords: Nanocomposites; EVA; Clay, Mechanical Properties; Gas Permeablity; Optical Transparency