Optical properties and electronic band structure of topological insulators (on A5 2B6 3 compound based)

Cataloged from PDF version of article.We have performed a first principles study of structural, electronic, and optical properties of rhombohedral Sb2Te3 and Bi 2Te3 compounds using the density functional theory within the local density approximation. The lattice parameters, bulk modulus, and its pressure derivatives of these compounds have been obtained. The linear photon-energy dependent dielectric functions and some optical properties such as the energy-loss function, the effective number of valance electrons and the effective optical dielectric constant are calculated and presented in the study. © 2013 Copyright Taylor and Francis Group, LLC

Development of an approximate method for quantum optical models and their pseudo-Hermicity

An approximate method is suggested to obtain analytical expressions for the eigenvalues and eigenfunctions of the some quantum optical models. The method is based on the Lie-type transformation of the Hamiltonians. In a particular case it is demonstrated that $E\times \epsilon$ Jahn-Teller Hamiltonian can easily be solved within the framework of the suggested approximation. The method presented here is conceptually simple and can easily be extended to the other quantum optical models. We also show that for a purely imaginary coupling the $E\times \epsilon$ Hamiltonian becomes non-Hermitian but $P\sigma _{0}$-symmetric. Possible generalization of this approach is outlined.Comment: Paper prepared fo the "3rd International Workshop on Pseudo-Hermitian Hamiltonians in Quantum Physics" June 2005 Istanbul. To be published in Czechoslovak Journal of Physic

Budd-chiari syndrome and renal arterial neurysms due to behcet disease: a rare association

Behcet’s disease is a multisystemic vasculitis of unknown etiology with a chronic relapsing course. Vasculitis in Behcet’s disease with predominant vascular involvement is the only vasculitis that affects both arteries and veins of any size. Involvement of the renal artery and inferior vena cava is rare among the arteries and veins, respectively. When disease affect the veins, it is in the form of thrombosis. Arterial complications include  aneurysms, stenosis and occlusions. Both rupture of arterial aneurysm and occlusion of suprahepatic veins,  causing Budd-Chiari syndrome, are associated with a high mortality rate. Vascular involvement is more common in male patients than in female patients. Men and patients with a younger age of onset present with a more severe prognosis. In this case report, we describe a very rare cause of intrarenal arterial aneurysm’s rupture with  previous Budd-Chiari syndrome due to Behcet’s disease and successful angiographic embolization of actively bleeding aneurysm

Coherent States for the Non-Linear Harmonic Oscillator

Wave packets for the Quantum Non-Linear Oscillator are considered in the Generalized Coherent State framerwork. To first order in the non-linearity parameter the Coherent State behaves very similarly to its classical counterpart. The position expectation value oscillates in a simple harmonic manner. The energy-momentum uncertainty relation is time independent as in a harmonic oscillator. Various features, (such as the Squeezed State nature), of the Coherent State have been discussed

An Iterative and Toolchain-Based Approach to Automate Scanning and Mapping Computer Networks

As today's organizational computer networks are ever evolving and becoming more and more complex, finding potential vulnerabilities and conducting security audits has become a crucial element in securing these networks. The first step in auditing a network is reconnaissance by mapping it to get a comprehensive overview over its structure. The growing complexity, however, makes this task increasingly effortful, even more as mapping (instead of plain scanning), presently, still involves a lot of manual work. Therefore, the concept proposed in this paper automates the scanning and mapping of unknown and non-cooperative computer networks in order to find security weaknesses or verify access controls. It further helps to conduct audits by allowing comparing documented with actual networks and finding unauthorized network devices, as well as evaluating access control methods by conducting delta scans. It uses a novel approach of augmenting data from iteratively chained existing scanning tools with context, using genuine analytics modules to allow assessing a network's topology instead of just generating a list of scanned devices. It further contains a visualization model that provides a clear, lucid topology map and a special graph for comparative analysis. The goal is to provide maximum insight with a minimum of a priori knowledge.Comment: 7 pages, 6 figure

Energy sinks: vibration absorption by an optimal set of undamped oscillators

This paper describes a new concept referred to here as “energy sinks” as an alternative to conventional methods of vibration absorption and damping. A prototypical energy sink envisioned here consists of a set of oscillators attached to, or an integral part of, a vibrating structure. The oscillators that make up an energy sink absorb vibratory energy from a structure and retain it in their phase space. In principle, energy sinks do not dissipate vibratory energy as heat in the classical sense. The absorbed energy remains in an energy sink permanently (or for sufficiently long durations) so that the flow of energy from the primary structure appears to it as damping. This paper demonstrates that a set of linear oscillators can collectively absorb and retain vibratory energy with near irreversibility when they have a particular distribution of natural frequencies. The approach to obtain such a frequency distribution is based on an optimization that minimizes the energy retained by the structure as a function of frequency distribution of the oscillators in the set. The paper offers verification of such optimal frequency spectra with numerical simulations and physical demonstrations

A rat model for the immune response to the intrauterine administration of BCG

This study was designed to investigate the changes in the numbers of lymphocytes, macrophages and plasma cells in the uterus and ileocecal lymph nodes of rats exposed to the intrauterine administration of Baeillus-Calmette Guerin (BCG). Thirty female Wistar Albino rats, age 6 months and weighing between 200-250 g, were assigned to the two experimental groups BCG treated and controls (n = 15). The intrauterine BCG injections were made using laparatomy in the diestrous cycle under Rompun and Ketalar anesthesia. 0.1 ml BCG were injected for each into cornu uteri while the control group received 0.1 ml sterile saline in the same place. Two weeks later, the rats in both groups were anesthetized with ether and decapitated. Uterus and ileocecal lymph nodes were processed to determine alpha naphthyl acid esterase (ANAE) - positive T lymphocytes and macrophages. The plasma cells were stained with the methyl green-pyronin method; It was found that the numbers of lymphocytes macrophages and plasma cells on the uterus increased (P<0.01) in BCG treated rats. In addition, the number of these cells also increased in the ileoeeeal lymph nodes indicating the presence of an immune response to the intrauterine BCG administration, It is concluded that although the rat was chosen as a model and ECG was given by the process of laparatomy in this study, intracervical administration of BCG tn the uterus should be studied clinically in cases of immune deficiency disorders related to the uterus. such as endometritis, myometritis, pyometra, endometriosis. infertility and implantation problems of domestic animals, to see if there is an increase in the immune response

Electron Spectroscopy and the Electronic Structure of KNbO3: First Principle Calculations

Cataloged from PDF version of article.The electronic structures of KNbO(3)were calculated within the density functional theory, and their evolution was analyzed as the crystal-field symmetry changes from cubic to rhombohedral via tetragonal phase. We carried out electron-energy loss spectroscopy experiments by using synchrotron radiation and compared the results with the theoretical spectra calculated within Density Functional Theory. The dominant role of the NbO(6)octahedra in the formation of the energy spectra of KNbO(3)compound was demonstrated. The anomalous behavior of plasmons in ferroelectrics was exhibited by the function representing the characteristic energy loss in the region of phase transition

Mechanical, electronic and optical properties of Bi2S3 and Bi2Se3 compounds: first principle investigations

Cataloged from PDF version of article.The structural, mechanical, electronic, and optical properties of orthorhombic Bi2S3 and Bi2Se3 compounds have been investigated by means of first principles calculations. The calculated lattice parameters and internal coordinates are in very good agreement with the experimental findings. The elastic constants are obtained, then the secondary results such as bulk modulus, shear modulus, Young's modulus, Poisson's ratio, anisotropy factor, and Debye temperature of polycrystalline aggregates are derived, and the relevant mechanical properties are also discussed. Furthermore, the band structures and optical properties such as real and imaginary parts of dielectric functions, energy-loss function, the effective number of valance electrons, and the effective optical dielectric constant have been computed. We also calculated some non-linearities for Bi2S3 and Bi2Se3 (tensors of elasto-optical coefficients) under pressur

A quantum exactly solvable non-linear oscillator related with the isotonic oscillator

A nonpolynomial one-dimensional quantum potential representing an oscillator, that can be considered as placed in the middle between the harmonic oscillator and the isotonic oscillator (harmonic oscillator with a centripetal barrier), is studied. First the general case, that depends of a parameter $a$, is considered and then a particular case is studied with great detail. It is proven that it is Schr\"odinger solvable and then the wave functions $\Psi_n$ and the energies $E_n$ of the bound states are explicitly obtained. Finally it is proven that the solutions determine a family of orthogonal polynomials ${\cal P}_n(x)$ related with the Hermite polynomials and such that: (i) Every ${\cal P}_n$ is a linear combination of three Hermite polynomials, and (ii) They are orthogonal with respect to a new measure obtained by modifying the classic Hermite measure.Comment: 11 pages, 11 figure