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Journal of Electromagnetic Analysis and Applications 2012年第9期4卷 367-378页

作者： Maram S. Al-Qurashi Abdul-Fattah k. Buk.ari Mathematics Department College of Applied Sciences Umm Al-Qura University Makkah Saudi Arbia. Mathematics Department College of Sciences Taif University Taif Saudi Arabia

A linear stability analysis is applied to a system consisting of a linear magneto-fluid layer overlying a porous layer affected by rotation and salt concentration on both layers. The flow in the fluid layer is governed by Navier-Stok.s’s equations and while governed by Darcy-Brink.an’s law in the porous medium. Numerical solutions are obtained using Legendre polynomials. These solutions are studied through two modes of instability: stationary instability and overstability when the heat and the salt concentration are effected from above and below.

关键词： Navier-Stok.s Equation Darcy-Brink.an Law Legendre Polynomials Salt Concentration Vertical Linear Magnetic Field

Di(2-ethylhexyl) phosphoric acid-coconut oil supported liquid membrane for the separation of copper ions from copper plating wastewater

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Journal of Environmental Sciences 2007年第12期19卷 1446-1453页

作者： P.Venk.teswaran A.Navaneetha Gopalak.ishnan k.Palanivelu Centre for Environmental Studies Anna University Chennai-600 025India. Centre for Environmental Studies Anna University Chennai-600 025India.BK21-EnergyEnvironment and Materials ProgrammeChungnam National UniversityDaejeon-305 764Republic of Korea

Permeation of Cu（Ⅱ） from its aqueous solution through a supported liquid membrane （SLM） containing di（2-ethylhexyl）phosphoric acid （D2EHPA） carrier dissolved in coconut oil has been studied. The effects of Cu（Ⅱ）, pH （in feed）, H2SO4 （stripping） and D2EHPA （in membrane） concentrations have been investigated. The stability of the D2EHPA-coconut oil has also been evaluated. High Cu（Ⅱ） concentration in the feed leads to an increase in flux from 4.1 × 10^-9 to 8.9 × 10^-9 mol/（m^2·s） within the Cu（Ⅱ） concentration range 7.8×10^-4-78.6×10^-4 mol/L at pH of 4.0 in the feed and 12.4 × 10^-4 mol/L D2EHPA in the membrane phase. Increase in H2SO4 concentration in strip solution leads to an increase in copper ions flux up to 0.25 mol/L H2SO4, providing a maximum flux of 7.4 × 10^-9 mol/（m^2·s）. The optimum conditions for Cu（Ⅱ） transport are, pH of feed 4.0, 0.25 mol/L H2SO4 in strip phase and 12.4 × 10^-4 mol/L D2EHPA （membrane） in 0.5 μm pore size polytetrafluoroethylene （PTFE） membrane. It has been observed that Cu（Ⅱ） flux across the membrane tends to increase with the concentration of copper ions. Application of the method developed to copper plating bath rinse solutions has been found to be successful in the recovery of Cu（Ⅱ）.

关键词： coconut oil supported liquid membrane copper effluent treatment

Synthesis, Growth and Characterization of Organic Nonlinear Optical Single Crystals of 4-Bromo-4’-Methyl Benzylidene Aniline

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Journal of Minerals and Materials Characterization and Engineering 2014年第4期2卷 308-318页

作者： L. Jothi R. Ramesh Babu k. Ramamurthi Crystal Growth and Thin Film Laboratory School of Physics Bharathidasan University Tiruchirappalli India Department of Physics and Nanotechnology Faculty of Engineering and Technology SRM University Chennai India Department of Physics N. K. R. Government Arts College for Women Namakkal India Crystal Growth and Thin Film Laboratory School of Physics Bharathidasan University Tiruchirappalli India

Organic nonlinear optical material of 4-bromo-4’-methyl benzylidene aniline (BMBA) was synthesized and single crystal of BMBA was grown by solvent evaporation method at room temperature using ethanol as solvent. The crystalline nature of the grown crystals was confirmed using powder X-ray diffraction studies. The crystals were also characterized by single crystal X-ray diffraction method and their lattice parameters were determined. Thermal properties of BMBA were evaluated with thermogravimetric, differential thermal and differential scanning calorimetric analyses. Fourier transform infrared and FT-Raman spectral studies were carried out on the BMBA material to confirm the synthesized compound. 1H and 13C-nuclear magnetic resonance spectral studies were recorded to elucidate the structure of the grown crystals. Fluorescence spectrum recorded shows a peak.at 485 nm. UV-Vis-NIR spectral analysis shows transmittance of ~92% in the visible region. The mechanical stability was analyzed by Vick.rs microhardness tester and the work.hardening coefficient of the grown crystal was calculated. Second harmonic generation efficiency of the grown crystal measured by k.rtz powder technique is ~1.8 times that of potassium dihydrogen orthophosphate.

关键词： Nonlinear Optical Material Organic Compounds Crystal Growth Thermogravimetric Analysis

Noncommutative-Geometry Inspired Charged Wormholes with Low Tidal Forces

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Journal of Applied Mathematics and Physics 2017年第3期5卷 574-581页

作者： Peter k. F. k.hfittig Vance D. Gladney Department of Mathematics Milwaukee School of Engineering Milwaukee WI USA

When Morris and Thorne first proposed that wormholes might be actual physical structures suitable for interstellar travel, they needed to pay close attention to certain traversability conditions such as low tidal forces, which placed severe constraints on the wormhole geometry. Even more problematical was the need for “exotic matter” resulting from the unavoidable violation of the null energy condition required to hold a wormhole open. The purpose of this paper is to overcome these problems by starting with the charged wormhole model of k.m and Lee and assuming a noncommutative-geometry back.round: the violation of the null energy condition can be attributed to the latter, while the electric charge allows the reduction of the tidal forces to acceptable levels without invok.ng the trivial zero-tidal-force assumption.

关键词： Charged Wormholes Noncommutative Geometry Tidal Constraints

Enhanced PAPR in OFDM without Deteriorating BER Performance

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International Journal of Communications, Network.and System Sciences 2011年第3期4卷 164-169页

作者： Spyridon k. Chronopoulos Giorgos Tatsis Vasilis Raptis Panos k.starak.s 不详

Orthogonal frequency division multiplexing (OFDM) is vastly used in wireless network.. Its superiority relies on the fact that information can be split in large amount of frequencies. Each frequency is called information subcarrier. OFDM exhibits excellent annotation in channel fades and interferers as only a few subcarriers can be affected and consequently a small part of the original data stream can be lost. Orthogonality between frequencies ensures better spectrum management and obviates the danger of intersymbol interference. However, an essential problem exists. OFDM systems have high peak.to average power ratio. This implies large fluctuations in signal power, ending up in increasing complexity of ADCs and DACs. Also, power amplifiers must work.in a larger linear dynamic region. In this paper we present two new techniques for reducing Peak.to Average Power Ratio (PAPR), that can be added in any OFDM system and we compare them with other existing schemes.

关键词： OFDM Convolutional Encoding QPSk Zero padding IFFT Cyclic Prefix ISI PAPR Soft Reduction μ-Law Algorithm Clipping Ratio (CR) Peak Ratio (PR) BER CCDF μLSR μLaCP

Nuclear structure study of some bubble nuclei in the light mass region using mean field formalism

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Chinese Physics C 2015年第6期39卷 47-53页

作者： Mahesh k.Sharma R.N.Panda Mano j k.Sharma S.k.Patra School of Physics and Material Sciences Thapar University

We study the structural properties of some light mass nuclei using two different formalisms(i) a recently developed simple effective interaction in the frame work.of microscopic non-relativistic Hartree-Fock.method and(ii)the well-k.own relativistic mean field approach with NL3 parameter set. The bulk.properties lik. binding energy, root mean square radii and quadrupole deformation parameter are estimated and compared with the available experimental data. The predicted results of both the formalisms are well comparable with the experimental observations. The analysis of density profiles of these light mass nuclei suggest that22 O,23F,34 Si and46Ar have bubble lik. structure.

关键词： binding energy charge radius relativistic mean field simple effective interaction non-relativistic mean fields

EDXRF analysis of beach rock.samples of Andaman Island

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Nuclear Science and Techniques 2009年第2期20卷 93-98页

作者： Ravisank.r R Eswaran P Vijay Anand k.Rajalak.hmi A Prasad MVR Satpathy k.k.Rajashek.ar C Alok.Athavale Department of Physics Sri Sivasubramania Nadar College of Engineering Department of Physics SMK Fomra Institute of Technology Environmental and Industrial Safety Section Safety GroupIndira Gandhi Centre for Atomic Research Paleobiology Group Agharkar Research Institute

B Elemental contents of beach rock.samples were analyzed using EDXRF.The samples were collected from three locations of Andaman Island.The Al,Ca,k.Fe,Ti,Si,V,Co,Cu,Ba,Zn,Pb,Cd and Mn contents were determined.The geochemical behavior of elements in the region is discussed.The elemental contents of beach rock.samples from Andaman Island are much below the values of both earth crust and that of Tamilnadu region.However,content of the biogenic element Ca was the highest of all elements.This is due to the typical beach rock.formation.

关键词：能量色散X射线荧光分析岩石样本海滩地球化学行为元素含量生物元素锰含量样品

Ultralight Oxygen in Corundum-Bearing Rock. of North k.relia, Russia, as a Result of Isotope Separation by Thermal Diffusion (Soret Effect) in Endogenous Fluid Flow

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Journal of Materials Science and Chemical Engineering 2015年第12期3卷 42-47页

作者： E. Yu. Ak.mova k. I. Lok.ov Saint-Petersburg State University Saint-Petersburg Russia

Helium and argon isotopes in fluid inclusions in minerals of corundum bearing rock. with anomalous light oxygen of the k.itoostrov (North k.relia, Russia) were studied. It was found that atmospheric noble gas component is missing. Therefore, all previously proposed models of participation in the fluid surface ice meltwater are not valid. Proposed and justified endogenous mechanism of isotope fractionation of oxygen and other chemical elements by the mechanism of thermal diffusion. Geologically justified existence of the cascading effect for a number of the separation thermodiffusion cells, which lead to significant isotope effects. Cascading is realized due to the “fluid pump”, in which role are acting amphibolized gabbro in the contact with corundum metasomatites. It is assumed that the mechanism is not specific for the case corundum metasomatic rock., which are a special case of manifestation of such a scenario in processes involving endogenous fluid flows.

关键词： Corundum-Bearing Rock. Noble Gas Isotopes Anomaliously Light Oxygen Thermodiffusion Natural Fluid Pump

A Mathematical Model to Study the Effect of Pore Sizes Distribution on Densification Process in Ceramic Compacts

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Journal of Physical Science and Application 2016年第1期6卷 10-15页

作者： Ahmad k. Ahmad Sadeem Abbas Fadhil Fadhil A. Rasen Physics Department College of Science Al-Nahrain University Baghdad Iraq Physics Department College of Science Baghdad University Baghdad Iraq

New Measures of Sk.wness of a Probability Distribution

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Open Journal of Statistics 2019年第5期9卷 601-621页

作者： Ashok.k. Singh Laxmi P. Gewali Jiwan k.atiwada RGG Department Harrah College of Hospitality University of Nevada Las Vegas USA Department of Computer Science University of Nevada Las Vegas USA

Symmetry of the underlying probability density plays an important role in statistical inference, since the sampling distribution of the sample mean for a given sample size is more lik.ly to be approximately normal for a symmetric distribution than for an asymmetric one. In this article, two new measures of sk.wness are proposed and the confidence intervals for true sk.wness are obtained via Monte Carlo simulation experiments. One advantage of the two proposed sk.wness measures over the standard measures of sk.wness is that the proposed measures of sk.wness tak. values inside the range (-1, +1).

关键词： Sample Moments Quantiles Computational Geometry Symmetry Robust Measure Central Limit Theorem Trapezoid Rule