Berry phase for spin--1/2 particles moving in a spacetime with torsion

Berry phase for a spin--1/2 particle moving in a flat spacetime with torsion is investigated in the context of the Einstein-Cartan-Dirac model. It is shown that if the torsion is due to a dense polarized background, then there is a Berry phase only if the fermion is massless and its momentum is perpendicular to the direction of the background polarization. The order of magnitude of this Berry phase is discussed in other theoretical frameworks.Comment: 9 pages. Some typos corrected, a discussion on propagating torsion is added, accepted for publication in Eur. Phys. J. C (2001

The universal R-matrix for the Jordanian deformation of sl(2), and the contracted forms of so(4)

We introduce a universal R matrix for the Jordanian deformation of \U{ \sl(2)}. Using \Uh{\so(4)}=\Uh{\sl(2)} \oplus {\rm U}_{-h}(\sl(2)), we obtain the universal R matrix for \Uh{\so(4)}. Applying the graded contractions on the universal R matrix of \Uh{\so(4)}, we show that there exist three distinct R matrices for all of the contracted algebras. It is shown that \Uh{\sl(2)}, \Uh{\so(4)}, and all of these contracted algebras are triangular.Comment: LaTeX, 8 page

Quantum reflection of massless neutrinos from a torsion-induced potential

In the context of the Einstein-Cartan-Dirac model, where the torsion of the space-time couples to the axial currents of the fermions, we study the effects of this quantum-gravitational interaction on a massless neutrino beam crossing through a medium with high number density of fermions at rest. We calculate the reflection amplitude and show that a specific fraction of the incident neutrinos reflects from this potential if the polarization of the medium is different from zero. We also discuss the order of magnitude of the fermionic number density in which this phenomenon is observable, in other theoretical contexts, for example the strong-gravity regime and the effective field theory approach.Comment: 8 pages, LaTe

A Triangular Deformation of the two Dimensional Poincare Algebra

Contracting the $h$-deformation of \SL(2,\Real), we construct a new deformation of two dimensional Poincar\'e algebra, the algebra of functions on its group and its differential structure. It is also shown that the Hopf algebra is triangular, and its universal R matrix is also constructed explicitly. Then, we find a deformation map for the universal enveloping algebra, and at the end, give the deformed mass shells and Lorentz transformation.Comment: 11 pages, LaTeX, Two figures upon reques

Application of neural network observer for on-line estimation of salient-pole synchronous generators' dynamic parameters using the operating data

Parameter identification is critical for modern control strategies in electrical power systems which is considered both dynamic performance and energy efficiency. This paper presents a novel application of ANN observers in estimating and tracking Salient-Pole Synchronous Generator Dynamic Parameters using time-domain, on-line disturbance measurements. The data for training ANN Observers are obtained through off-line simulations of a salient-pole synchronous generator operating in a one-machine-infinite-bus environment. The Levenberg-Marquardt algorithm has been adopted and assimilated into the back-propagation learning algorithm for training feed-forward neural networks. The inputs of ANNs are organized in conformity with the results of the observability analysis of synchronous generator dynamic parameters in its dynamic behavior. A collection of ANNs with same inputs but different outputs are developed to determine a set of the dynamic parameters. The ANNs are employed to estimate the dynamic parameters by the measurements which are carried out within each kind of fault separately. The trained ANNs are tested with on-line measurements to identify the dynamic parameters. Simulation studies indicate the ANN observer has a great ability to identify the dynamic parameters of salient-pole synchronous generator. The results also show that the tests which have given better results in estimation of each dynamic parameter can be obtained

Content validity of national post marriage educational program using mixed methods

Background: Although the validity of content of program is mostly conducted with qualitative methods, this study used both qualitative and quantitative methods for the validation of content of post marriage training program provid-ed for newly married couples. Content validity is a preliminary step of obtaining authorization required to install the program in country's health care system. Methods: This mixed methodological content validation study carried out in four steps with forming three expert panels. Altogether 24 expert panelists were involved in 3 qualitative and quantitative panels; 6 in the first item devel-opment one; 12 in the reduction kind, 4 of them were common with the first panel, and 10 executive experts in the last one organized to evaluate psychometric properties of CVR and CVI and Face validity of 57 educational objectives. Results: The raw data of post marriage program had been written by professional experts of Ministry of Health, using qualitative expert panel, the content was more developed by generating 3 topics and refining one topic and its respec-tive content. In the second panel, totally six other objectives were deleted, three for being out of agreement cut of point and three on experts' consensus. The validity of all items was above 0.8 and their content validity indices (0.8-1) were completely appropriate in quantitative assessment. Conclusion: This study provided a good evidence for validation and accreditation of national post marriage program planned for newly married couples in health centers of the country in the near future. © 2015, Iranian Journal of Public Health. All right reserved

Kinetic and Thermodynamic Studies of Charge-Transfer Complex Formation between Imipramine and 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in Acetonitrile and Dichloromethane Solutions

Spectro-kinetic studies revealed the formation of charge-transfer (CT) complex of imipramine as an electron donor with π acceptor 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in acetonitrile and dichloromethane solutions. The resulted CT complexes exhibit spectra that were remarkably different fromthose of the donor and acceptor. The stoichiometry of the resulting complex was found to be 1:1 by the method of Job‘s continuous variation. The formation constants and thermodynamic parameters of the resulting electron-donor-acceptor (DA) complexes were determined by Benesi-Hildebrand and van’t Hoff equations, respectively. The time-dependent spectra recorded after mixing donor and acceptor has been related to an immediate formation of DA complex, which is followed by two relatively slow consecutive reactions. The pseudo-first-order rate constants for the formation of the ionic intermediate and the final product have been evaluated at various temperatures by computer fitting of the absorbance-time data to appropriate equations. The activation parameters, i.e. activation energy, enthalpy, and entropy of activation were computed from temperature dependence of the rate constants. The observed results afford evidence concerning the critical role of solvent polarity on the kinetics and stability of the resulting charge transfer complexes. The ionization potential of the donor in the two solvents was estimated and compared with the theoretical values.KEYWORDS Charge-transfer complex, imipramine, DDQ, ionization potential, kinetic, thermodynamic