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Convective, Diffusive Effects on Magnetic Fields and Eddy Current in Compulsators
Compulsators are being designed at ever increasing energies and energy densities and are required to deliver energy to the load in less than 10 ms. These require high speeds of operation and dense spacing of conductors. Diffusion of magnetic fields into the conductors and the formation of nonuniform, time-dependent distribution of eddy currents become dominant design considerations due to their major mechanical, thermal, and thermodynamic impact. A semi-analytical method has been developed for the two-dimensional analysis of field diffusion and eddy currents in high speed rotary machines to aid design decisions. Analytical results for fields are utilized and computations are restricted to the conductor domains alone. The semi-analytical method has been tested with two conductors (one in the stator and one in the rotor rotating at high speed). The resulting distributions of fields and eddy currents are presented.Center for Electromechanic
Bis[5-(4-bromophenyl)-4-(tert-butoxycarbonyl)pyrrolidine-2-carboxylato]copper(II) dihydrate
In the title compound, [Cu(C16H19BrNO4)2]·2H2O, the CuII ion resides on an inversion centre and is coordinated by two O and two N atoms from two enantiomeric 5-(4-bromophenyl)-4-(tert-butoxycarbonyl)pyrrolidine-2-carboxylate ligands in a distorted square-planar geometry. The relative stereochemistry of the three stereogenic C atoms in each ligand has been determined. In the crystal, intermolecular N—H⋯O and O—H⋯O hydrogen bonds link the molecules into layers parallel to the bc plane. The crystal studied was twinned by pseudomerohedry with twin fractions of 0.719 (3) and 0.281 (3)
Thermo-Mechanical Modeling of Friction Stir Spot Welding and Numerical Solution With The Finite Element Method
In this paper, friction stir spot welding (FSSW) of magnesium sheets were analyzed using finite element method (FEM). Various tool shoulder types used in Friction stir welding (FSW) were chosen as different parameter. Thermic simulations were showed that thermic conditions vary with tool shoulder design types used in friction stir welding. Heat energy input (Q) of numerical model was solved analytically and calculated based on the various parameter values. Friction factor surface pressure and materials thermic properties which are changing with generated heat during friction welding were also considered in the FEM analysis. Thermic field model was solved numerically and results were presented
2-[(1RS,3RS,3aRS,6aSR)-5-Benzyl-4,6-dioxo-3-phenyloctahydropyrrolo[3,4-c]pyrrol-1-yl]acetamide
In the title compound, C21H21N3O3, the relative stereochemistry of the four stereogenic C atoms has been determined. The dihedral angle between the phenyl rings is 77.63 (7)°. In the crystal, ribbons spread along the a axis are formed by N—H⋯O hydrogen bonds. C—H⋯π interactions also occur
Step Bunching with Alternation of Structural Parameters
By taking account of the alternation of structural parameters, we study
bunching of impermeable steps induced by drift of adatoms on a vicinal face of
Si(001). With the alternation of diffusion coefficient, the step bunching
occurs irrespective of the direction of the drift if the step distance is
large. Like the bunching of permeable steps, the type of large terraces is
determined by the drift direction. With step-down drift, step bunches grows
faster than those with step-up drift. The ratio of the growth rates is larger
than the ratio of the diffusion coefficients. Evaporation of adatoms, which
does not cause the step bunching, decreases the difference. If only the
alternation of kinetic coefficient is taken into account, the step bunching
occurs with step-down drift. In an early stage, the initial fluctuation of the
step distance determines the type of large terraces, but in a late stage, the
type of large terraces is opposite to the case of alternating diffusion
coefficient.Comment: 8pages, 16 figure
A systematic study on luminescence characterization of lanthanide-doped BeO ceramic dosimeters
This work aimed to investigate the luminescent characteristics of lanthanide and alkali metal ion-doped BeO ceramic pellets prepared using the co-precipitation synthesis technique for Optically Stimulated Luminescence (OSL) dosimetry applications. In this study, BeO nano phosphor was doped with lanthanides (Ln(3+)) Eu3+, Ce3+, Nd3+, Yb3+, Er3+, Gd3+, Tb3+, Tm3+, Sm3+, Pr3+, and Dy3+ and co-doped with Na+, and characterized using radioluminescence (RL), thermoluminescence (TL) and OSL techniques. Lanthanides introduced as dopants not only affected the luminescence centers but also changed the luminescence mechanisms. The RL spectra of lanthanide-doped BeO samples showed that they mostly possess dominant emissions in the narrow bands (between 200 and 450 nm) in the UV region. OSL emission bands were found to be located between similar to 250 and similar to 390 nm. The results have demonstrated that the incorporation of appropriate Ln(3+) and alkali metal ion dopants and their optimum concentrations enhanced the luminescence intensity of undoped BeO. The studied BeO:Na-5%,Ce-0.01%,Er-0.01%, BeO:Na-5%,Ce-0.005%,Tb-0.05%, and BeO:Na-5%,Ce-0.01%,Dy-0.01% ceramics can be regarded as highly sensitive controllable luminescence dosimeters. The range of sensitivity of those samples is such that their most probable use in clinical therapy dosimetry rather than in health physics. (C) 2021 Elsevier B.V. All rights reserved
Entanglement and teleportation via chaotic system
The dynamics of entangled state interacting with a single cavity mode is
investigated in the presence of a random parameter. We have shown that degree
of entanglement decays with time and rate of decay is defined by features of
random parameter. Quantum teleportation through dissipative channal and
teleportation fidelity as a function of damping rates has been studied. The
sensitivity of the fidelity with respect to random parameter is discussed. We
have evaluated the time interval during which one can perform the quantum
teleportation and send the information with reasonable fidelity, for a given
values of correlation length of random parameter.Comment: Accepted in Physica
The SFXC software correlator for Very Long Baseline Interferometry: Algorithms and Implementation
In this paper a description is given of the SFXC software correlator,
developed and maintained at the Joint Institute for VLBI in Europe (JIVE). The
software is designed to run on generic Linux-based computing clusters. The
correlation algorithm is explained in detail, as are some of the novel modes
that software correlation has enabled, such as wide-field VLBI imaging through
the use of multiple phase centres and pulsar gating and binning. This is
followed by an overview of the software architecture. Finally, the performance
of the correlator as a function of number of CPU cores, telescopes and spectral
channels is shown.Comment: Accepted by Experimental Astronom
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