Effective harmonic oscillator description of anharmonic molecular vibrations

The validity of an effective harmonic oscillator approximation for anharmonic molecular vibrations is tested and compared with vibrational self consistent field and vibrational configurational interaction results. The effective harmonic oscillator is constructed variationally, by taking the trial wave function as a harmonic oscillator eigenfunction with the centroid and width parameter as variational paraeters. It is found that the effective harmonic oscillator approximation provides a description of the anharmonic eigenstates very similar to the vibrational self consistent field results. Coriolis coupling is also included in these studies

On the development of many-body theories for intramolecular dynamics

The efficacy of using time-dependent generalizations of the closed shell coupled cluster method for intramolecular processes associated with non-degenerate vacuum in the context of molecular absorption spectra is examined. Since the separability requirements are built into such an ansatz for the time evolution operator, it is possible to develop approximations which can take into account any number of modes, with much less computational effort than in a calculation by basis set expansion

Dynamic Stability and Analysis of SMIB system with FLC Based PSS including Load Damping Parameter Sensitivity

This paper studies Dynamic Analysis and Stability of Single machine connected to infinite bus (SMIB) with power system stabilizer (PSS) in presence of Fuzzy logic controller (FLC) including load damping parameter sensitivity. Here PSS is modeled using fuzzy logic controller and the response is compared with the responses of the system in presence of conventional PI, PID controllers including load damping parameters sensitivity. In case of FLC based PSS the responses are compared different load damping parameters. Matlab-Simulink is used to test the results

Diversity pattern elucidating choice of parents for hybridization in varieties of groundnut, Arachis hypogaea L.

Genetic divergence within and between the four varietal groups, Spanish bunch, Valencia, Virginia bunch and Virginia runner, of groundnut (Arachis hypogaea L.) was assessed by Mahalanobis's D2 statistic using a representative sample of 40 germplasm lines in each group. Estimates of divergence were based on 17 characters spanning the seedling, flowering, post-flowering and harvest stages. The diversity within bunch groups was high enough to form six different clusters out of the total sixteen. The method used was thus efficient in diagnosing within-group divergence. The clustering pattern of the varieties remained essentially the same when the experiment was repeated on a sub-sample of 48 germplasm lines in the next season. The results revealed that identified bunch x bunch crosses involving divergent parents could combine earliness with productivity, and should be used to complement the currently advocated bunch x runner crosses. Flowering time, weight of mature pods, shelling percentage and seedling attributes, like number of leaves and shoot-root dry weight ratio, were found to be important in assessing genetic variance

Bibliografia Lul·lística

The open circuit voltage recovery transient of a positive-limited nickel-cadmium cell has been theoretically analysed taking into account the double-layer charging process, polarization due to charge transfer, mass transfer and ohmic resistance in the cell, and self-discharge due to any internal electronic short. Expressions have been obtained for charge transfer and mass transfer polarization. Experimental data on open circuit voltage recovery transients obtained for nickel-cadmium cells indicate that the rate of the electrode reaction at the positive electrode of the cells is controlled by mass transfer process

Optimized Coefficients of Interpolation Filter To Adapt Statistical Property of Each Image

Spatial transform has assumed an essential part in most picture and video coding routines. Wavelet change has numerous points of interest, for example, multi-determination representation, great vitality compaction and de-correlation. We propose another weighted versatile lifting (WAL)- based wavelet change that is intended to take care of the issues existing in the past versatile directional lifting (ADL) approach. The proposed methodology utilizes the weighted capacity to ensure that the prediction and update stages are predictable, the directional addition to enhance the introduction property of added image, and adaptive interpolation filter to adjust to statistical property of each image

SIMULATION AND PERFORMANCE ANALYSIS OF CNG FUELED HCCI ENGINE

ABSTRACT Compressed Natural Gas (CNG) is a difficult fuel to use in a Homogenous Charge Compression Ignition (HCCI) engine because of high octane number, high auto-ignition temperature, and rapid heat release. These properties force CNG HCCI engines to use extreme levels of intake heating. The Homogeneous Charge Compression Ignition concept has the potential to meet the need for a high efficiency and low emission engine. Fluent is one of the promising operating tools in the computational fluid dynamics. In the present study the Computational Fluid dynamics (CFD) code FLUENT is used to model complex combustion phenomenon in homogeneous charge compression Ignition engine. The variation of various properties like the peak cylinder pressure, peak cylinder temperature at various crank angles, at different relative air fuel mixture inlet temperatures and with hemi spherical combustion chamber and toroidal bowl has been studied. It was found that heated inlet air fuel mixture enhance combustion, peak cylinder pressure, peak cylinder temperature and change peak pressure timing

Quantum phases of dimerized and frustrated Heisenberg spin chains with s = 1/2, 1 and 3/2: an entanglement entropy and fidelity study

We study here different regions in phase diagrams of the spin-1/2, spin-1 and spin-3/2 one dimensional antiferromagnetic Heisenberg systems with frustration (next-nearest-neighbor interaction $J_2$) and dimerization ($\delta$). In particular, we analyze the behaviors of the bipartite entanglement entropy and fidelity at the gapless to gapped phase transitions and across the lines separating different phases in the $J_2-\delta$ plane. All the calculations in this work are based on numerical exact diagonalizations of finite systems.Comment: 12 pages, 15 figures; provided some finite size analysis results, some changes in text accordingly; to appear in J. Phys.: Condens. Matte