Impulse voltage distribution and frequency response of intershield windings

Impulse voltage distributions in continuous disk windings are nonlinear, due to the small series capacitance of the winding. Consequently, transformer manufacturers often design large power transformers with interleaved windings to increase series capacitance, but in doing so reduce the value of the initial impulse voltage distribution coefficient α given by α = √(Cg/Cs), (1) where Cg is the shunt capacitance and Cs is the series capacitance of the winding. Sometimes fully interleaved windings are employed because they are more reliable, ensuring that the transformer will operate properly under lightning strike

Geometric approach to nonlinear coherent states using the Higgs model for harmonic oscillator

In this paper, we investigate the relation between the curvature of the physical space and the deformation function of the deformed oscillator algebra using non-linear coherent states approach. For this purpose, we study two-dimensional harmonic oscillators on the flat surface and on a sphere by applying the Higgs modell. With the use of their algebras, we show that the two-dimensional oscillator algebra on a surface can be considered as a deformed one-dimensional oscillator algebra where the effect of the curvature of the surface is appeared as a deformation function. We also show that the curvature of the physical space plays the role of deformation parameter. Then we construct the associated coherent states on the flat surface and on a sphere and compare their quantum statistical properties, including quadrature squeezing and antibunching effect.Comment: 12 pages, 7 figs. To be appeared in J. Phys.

Influence of gravitational field on quantum-nondemolition measurement of atomic momentum in the dispersive Jaynes-Cummings model

We present a theoretical scheme based on su(2) algebra to investigate the influence of homogeneous gravitational field on the quantum nondemolition measurement of atomic momentum in dispersive Jaynes-Cummings model. In the dispersive Jaynes-Cummings model, when detuning is large and the atomic motion is in a propagating light wave, we consider a two-level atom with quantized cavity-field in the presence of a homogeneous gravitational field. We derive an effective Hamiltonian describing the dispersive atom-field interaction in the presence of gravitational field. We can see gravitational influence both on the momentum filter and momentum distribution. Moreover, gravitational field decreases both tooth spacing of momentum and the width of teeth of momentum.Comment: 21 pages, 8 figure

Damage analysis and fracture toughness evaluation in a thin woven composite laminate under static tension using infrared thermography

This work deals with the issue of damage growth in thin woven composite laminates subjected to tensile loading. The conducted tensile tests were monitored on-line with an infrared camera, and tested specimens were analysed using Scanning Electron Microscopy (SEM). Combined with SEM micrographs, observation of heat source fields enabled us to assess the damage sequence. Transverse weft cracking was confirmed to be the main damage mode and fiber breakage was the final damage leading to failure. For cracks which induce little variation of specimen stiffness, the classic “Compliance method” could not be used to compute energy release rate. Hence, we present here a new procedure based on the estimation of heat source fields to calculate the energy release rate associated with transverse weft cracking. The results are then compared to those computed with a simple 3D inverse model of the heat diffusion problem and those presented in the literature

Digitization of the Canadian Parliamentary debates

This paper describes the digitization and enrichment of the Canadian House of Commons English Debates from 1901 to present. We start by laying out the general framework in which this project took place and then present the structure of the database and provide guidelines to prospective users. The paper concludes with the introduction of www.lipad.ca, an online platform designed as a hub for archiving Canadian political data, with the parliamentary proceedings at the centre of its architecture

Effect of Ursodeoxycholic Acid on Pentylenetetrazole Kindling and Kindling Induced Memory Impairment in Rat

BACKGROUND AND OBJECTIVE: Epilepsy is one of the common diseases of the brain that about 30-40% of patients with epilepsy experience recurent attacks due to drug resistance. Recently, the beneficial effects of Ursodeoxycholic acid on brain disorders have been considered. The aim of this study was to evaluate the effect of Ursodeoxycholic acid(UDCA)on the Pentylenetetrazole (PTZ) induced kindling, and related learning and memory impairments on Morris water maze. METHODS: This experimental study was done on 32 male Winstar rats divided into 4 groups. The first(n=7)and the second(n=9)groups have received three injections of 0.5 ml NaCl or 50 mg/kg of UDCA respectively and third(n=7) and fourth(n=9) groups have received fifteen injections of 0.5 ml NaCl or 50 mg/kg of UDCA respectively. All injections were given intraperitoneally(ip)(every 48 hours). In all groups, chemical kindling were started after third injections. Twenty-four hour after the last injection, spatial memory was investigated in the Morris water maze. FINDING: Fifteen injections of UDCA significantly reduced the seizure stage from 3.5±0.17 to 3.08±0.11 and duration of stages five from 12.37±1.21 to 8.43±1.09 and increased time to reach the stage five seizures from 1021.65±72.07 to 1252.41±49.63 as compared to control group. However, three injections of UDCA have no effect on the kindling process. However, three time administration of UDCA significantly increased reference memory from 18.72±1.2 s to 26.11±1.8 s. CONCLUSION: Ursodeoxycholic acid inhibits chemical kindling and improves kindling induced memory impairment