Correlation effects in a one-dimensional electron gas with short-range interaction

Cataloged from PDF version of article.We study the correlation effects in a one-dimensional electron gas with repulsive delta-function interaction. The correlation effects are described by a local-held correction which takes into account the short-range correlations. We find that the ground state energy is in good agreement with the exact result up to intermediate coupling strengths, showing an improvement over the STLS approximation. The compressibility, the static structure factor and the pair-correlation function are also calculated within the present approximation. (C) 1999 Elsevier Science Ltd. All rights reserved

Effects of Trade Tariffs on Domestic Economies and Global Trade: an Exploratory Analysis

2019 dissertation for MSc. Purpose – Firstly, the purpose of this study is to examine the trade tariffs, its reasons to be imposed and more importantly its outcomes to the economies. Furthermore, the outcomes of the trade tariffs will be investigated both for domestic economies and in global trade. It shortly focus on to explore the relation between the tariffs and economic growth. Methodology – The research has conducted by using exploratory design, it aims to explore while researching. Interpretivist approach has been applied. Secondary data collection has followed, also quantitative and qualitative approach of data has used for analyzing the research objectives to gain in-depth understanding. Multiple samples has used and purposeful sampling method has been applied. In order to validate the findings, convergence method will be applied. To test the reliability of findings, stability method will be applied. Findings – Findings show that there are certain outcomes of the trade tariffs. However, the precision of outcomes are not certain, as there are certain variables that can change the outcomes of tariffs probabilistically. The outcomes could be in favor of the nation or not. Therefore, all theories couldn’t be proved in this research. Practical Implications – The research have practical implications for governments while imposing trade tariffs. The study has found that the global trade is vulnerable especially because of domination of some currency which has been used in international trade. Therefore it has been recommended to encourage nations to trade with their own currencies in between many other nations. Therefore trouble in one currency would not be affecting other nations. Another recommendation is that nations should avoid radical decisions on trade tariffs

Methyldecalin hydrocracking over palladium/zeolite-X

Cataloged from PDF version of article.Hydrocracking of methyldecalin over Pd/REX has been studied with surface sensitive techniques in the critical temperature range 325-350 degrees C. Results from in situ characterization of adsorbed species, and post-reaction analysis of the catalyst surface by infrared and photoemission spectroscopies, were related to product distributions. The results are discussed in light of quantum chemical calculations of free and catalyst bound intermediates, following ring-opening reactions. Liquid and gaseous products were detected by infrared and WNis spectroscopies. Apparent activation energies of product formation hydrogen consumption, over a broader temperature range, were derived from previous autoclave experiments. An increase in temperature, 325-350 degrees C, results in a shift from preferred cracking products to aromatics, an enhanced level of light hydrocarbon off-gases, and a higher coverage of carbonaceous residues. The increased level of carbonaceous residues is accompanied by a lowered coverage of the reactant, at the surface. The altered product distribution can be characterized by apparent single activation energies, valid from 300 to 450 degrees C. Methane and aromatics show a similar rapid increase with temperature, hydrogen consumption a more timid increase, indicating a reaction limited by diffusion, and cycloalkane production a modest inverse temperature dependence. Fully hydrogenated ring-opening products represent valuable fuel components, but hydrogen deficiency can instead lead to chemisorbed precursors to coke. Our calculations show that cyclohexane, 1,2-diethyl, 3-methyl has a lower heat of formation than the corresponding surface intermediates, but a small enthalpy advantage can easily be countered by entropy effects at higher temperatures. This balance is critical to the formation of preferred products, instead of catalyst deactivation and aromatics. The theoretical results further show that surface intermediates, where the terminating hydrogen is replaced by a C-O bond, have distinct vibrations around 1150 cm(-1). (C) 2000 Elsevier Science Ltd. All rights reserved

Conserved mass models with stickiness and chipping

We study a chipping model in one dimensional periodic lattice with continuous mass, where a fixed fraction of the mass is chipped off from a site and distributed randomly among the departure site and its neighbours; the remaining mass sticks to the site. In the asymmetric version, the chipped off mass is distributed among the site and the right neighbour, whereas in the symmetric version the redistribution occurs among the two neighbours. The steady state mass distribution of the model is obtained using a perturbation method for both parallel and random sequential updates. In most cases, this perturbation theory provides a steady state distribution with reasonable accuracy.Comment: 17 pages, 4 eps figure

The spectral shift function and Levinson's theorem for quantum star graphs

We consider the Schr\"odinger operator on a star shaped graph with $n$ edges joined at a single vertex. We derive an expression for the trace of the difference of the perturbed and unperturbed resolvent in terms of a Wronskian. This leads to representations for the perturbation determinant and the spectral shift function, and to an analog of Levinson's formula

Many-body vertex corrections in a one-dimensional electron system interacting with a long-range Coulomb potential

We study the quasiparticle properties of a one-dimensional electron gas interacting with a long-range electron-electron interaction. The electron self-energy is calculated using the leading-order dynamical-screening approximation with (GWΓ approximation) and without the vertex corrections (GW approximation). The calculated one-electron properties such as the spectral function, damping rate, and also the momentum distribution indicate the significance of vertex corrections at low densities. ©2000 The American Physical Society

Pluronic polymer capped biocompatible mesoporous silica nanocarriers

A facile self-assembly method is described to prepare PEGylated silica nanocarriers using hydrophobic mesoporous silica nanoparticles and a pluronic F127 polymer. Pluronic capped nanocarriers revealed excellent dispersibility in biological media with cyto- and blood compatibilities. © 2013 The Royal Society of Chemistry