3,217 research outputs found

    The orbit method solution for the deformed three coupled scalar fields

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    In this work, we present a deformed solutions starting from systems of three coupled scalar fields with super-potential W(ϕ1,ϕ2,ϕ3)W(\phi_1, \phi_2, \phi_3) by orbit method. First, we deform the corresponding super-potential and obtain defect solutions. It is shown that how to construct new models altogether with its defect solutions in terms of the non-deformed model. Therefore, we draw the graph of super-potential and different fields in terms of x.x. So we observe that the graphs for deformed and non - deformed cases are changed by the scale.Comment: 9 pages, 5 figure

    Thermodynamics of string black hole with hyperscaling violation

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    In this paper, we start with black brane and construct specific space-time which violates hyperscaling. In order to obtain the string solution we apply Null-Melvin-Twist and KKKK-reduction. By using the difference action method we study thermodynamics of system to obtain Hawking-Page phase transition. In order to have hyperscaling violation we need to consider θ=d2.\theta=\frac{d}{2}. In that case the free energy FF is always negative and our solution is thermal radiation without a black hole. Therefore we find that there is not any Hawking-Page transition. Also, we discuss the stability of system and all thermodynamical quantities.Comment: 12 pages. Accepted for publication in EPJ

    Asymptomatic bacteriuria and pyuria in patients with chronic renal failure undergoing hemodialysis at dialysis centers in Kermanshah, Iran

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    Pyuria is the presence of increased numbers of polymorphonuclear leukocytes in the urine and is evidence of an inflammatory response in the Urinary Tract Infection (UTI). The aim of this study is determination asymptomatic bacteriuria and pyuria in patients undergoing hemodialysis with chronic renal failure. Out of 103 patients with renal failure undergoing hemodialysis who were able to produce urine with clean catch way, we received urine sample. All samples were examined by the Microbiologist in Central Laboratory of Kermanshah, Iran. The mean age for the patients at diagnosis was 42.4 years (range, 20-67 years). Sixty-four patients (62.5) were male and thirty-nine (37.5) were female. Results have been showed 39 cases were aged between 44-49 years and the highest number cases were middle-aged. Out of 31 patients with leukocytosis, 14 patients had age between 44-49 years and majority of them were male. Pyuria(>10 WBC/HPF or 10 WBC/HPF) developed colony count more than 105 colony-forming units per milliliter that indicating positive culture. Microorganisms didn�t grow in patients (10/19) with pyuria (10 WBC/HPF is a good marker for significant bacteriuria in these patients. © 2015 Academic Journals Inc

    High Sensitivity AC Field Measurement Using Rhombic Inducer

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    The principle behind the ac field measurement (ACFM) technique has been explained in [1]. In this technique, a thin-skin eddy current is induced in the metal under test. The current is perturbed by defects in the metal surface and the result is reflected in the magnetic field above the surface. A probe is used to detect perturbations in this field

    A Multi-scale Approach for Simulations of Kelvin Probe Force Microscopy with Atomic Resolution

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    The distance dependence and atomic-scale contrast observed in nominal contact potential difference (CPD) signals recorded by KPFM on surfaces of insulating and semiconducting samples, have stimulated theoretical attempts to explain such effects. We attack this problem in two steps. First, the electrostatics of the macroscopic tip-cantilever-sample system is treated by a finite-difference method on an adjustable nonuniform mesh. Then the resulting electric field under the tip apex is inserted into a series of atomistic wavelet-based density functional theory (DFT) calculations. Results are shown for a realistic neutral but reactive silicon nano-scale tip interacting with a NaCl(001) sample. Bias-dependent forces and resulting atomic displacements are computed to within an unprecedented accuracy. Theoretical expressions for amplitude modulation (AM) and frequency modulation (FM) KPFM signals and for the corresponding local contact potential differences (LCPD) are obtained by combining the macroscopic and atomistic contributions to the electrostatic force component generated at the voltage modulation frequency, and evaluated for several tip oscillation amplitudes A up to 10 nm. Being essentially constant over a few Volts, the slope of atomistic force versus bias is the basic quantity which determines variations of the atomic-scale LCPD contrast. Already above A = 0.1 nm, the LCPD contrasts in both modes exhibit almost the same spatial dependence as the slope. In the AM mode, this contrast is approximately proportional to A1/2A^{-1/2}, but remains much weaker than the contrast in the FM mode, which drops somewhat faster as A is increased. These trends are a consequence of the macroscopic contributions to the KPFM signal, which are stronger in the AM-mode and especially important if the sample is an insulator even at sub-nanometer separations where atomic-scale contrast appears.Comment: 19 pages, 13 figure

    Fast directional spatially localized spherical harmonic transform

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    We propose a transform for signals defined on the sphere that reveals their localized directional content in the spatio-spectral domain when used in conjunction with an asymmetric window function. We call this transform the directional spatially localized spherical harmonic transform (directional SLSHT) which extends the SLSHT from the literature whose usefulness is limited to symmetric windows. We present an inversion relation to synthesize the original signal from its directional-SLSHT distribution for an arbitrary window function. As an example of an asymmetric window, the most concentrated band-limited eigenfunction in an elliptical region on the sphere is proposed for directional spatio-spectral analysis and its effectiveness is illustrated on the synthetic and Mars topographic data-sets. Finally, since such typical data-sets on the sphere are of considerable size and the directional SLSHT is intrinsically computationally demanding depending on the band-limits of the signal and window, a fast algorithm for the efficient computation of the transform is developed. The floating point precision numerical accuracy of the fast algorithm is demonstrated and a full numerical complexity analysis is presented.Comment: 12 pages, 5 figure
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