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Mechanical properties of Ga_xIn_(1-x)As_yP_(1-y)/GaAs system at different temperatures and pressures

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Chinese Physics b 2015年第9期24卷 313-318页

作者： A.r.Degheidy E.b.Elkenany Department of Physics Faculty of ScienceMansoura University

The mechanical properties, such as the elastic constants C11, C12, C44, and bulk, Young＇s, and shear moduli, of a Ga x In1-x As y P1-y alloy lattice matching to a Ga As substrate are calculated for various As concentrations. The calculations are based on the pseudo-potential method within the virtual crystal approximation containing the effective disorder potential. The variations of the studied properties with pressure and temperature are investigated. A comparison between the calculated results and the available published data for binary parent compounds shows that they have good agreement,while the calculated results for the quaternary alloys at various temperature and pressure may be taken as a reference.

关键词： elastic constants temperature and pressure electronic band gaps

SECOND-OrDEr INTErACTION OF IrrEGULAr WAVES WITH A TrUNCATED COLUMN

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Acta Mechanica Sinica 1997年第2期13卷 130-142页

作者： J.b.Huang r.EatockTaylor Department of Engineering Science University of OxfordParks RoadOxfordOX1 3PJUK

A complete semi-analytical solution is obtained for second-order diffraction of plane bichromatic waves by a fixed truncated circular *** fluid domain is divided into interior and exterior *** the exterior region,the second-order velocity potential is expressed in terms of‘locked-wave’and‘free-wave’ components,both are solved using Fourier and eigenfunction *** re- sulting‘locked wave’potential is expressed by one-dimensional Green's integrals with oscillating *** order to increase computational efficiency,the far-field part of the integrals are carried out *** in both regions are matched on the interface by the potential and its normal derivative continuity *** on the present approach,the sum-and difference-frequency potentials are efficiently evaluated and are used to generate the quadratic transfer functions which correlates the incident wave spectrum with second-order forcing spectrum on the *** sum-frequency QTFs for a TLP column are present,which are compared for some frequency pairs with those from a fully numerical *** agreement has been *** spectra for a case study TLP column,generated using the semi-analytical solution are *** given are the results for nonlinear wave field around the column.

关键词： marine hydrodynamics nonlinear wave force wave-structure interaction second-order wave diffraction

Motion of a permeable shell in a spherical container filled with non-Newtonian fluid

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Applied Mathematics and Mechanics(English Edition) 2017年第12期38卷 1697-1708页

作者： V.MISHrA b.r.GUPTA Department of Mathematics Jaypee University of Engineering and TechnologyMadhya Pradesh 473226India

This paper presents an analytical study of creeping motion of a permeable sphere in a spherical container filled with a micro-polar fluid. The drag experienced by the permeable sphere when it passes through the center of the spherical container is studied. Stream function solutions for the flow fields are obtained in terms of modified bessel functions and Gegenbauer functions. The pressure fields, the micro-rotation components, the drag experienced by a permeable sphere, the wall correction factor, and the flow rate through the permeable surface are obtained for the frictionless impermeable spherical container and the zero shear stress at the impermeable spherical container. Variations of the drag force and the wall correction factor with respect to different fluid parameters are studied. It is observed that the drag force, the wall correction factor, and the flow rate are greater for the frictionless impermeable spherical container than the zero shear stress at the impermeable spherical container. Several cases of interest are deduced from the present analysis.

关键词： micro-polar fluid permeable sphere Darcy law stream function drag force wall correction factor spherical container

Exact solutions to drift-flux multiphase flow models through Lie group symmetry analysis

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Applied Mathematics and Mechanics(English Edition) 2015年第8期36卷 1105-1112页

作者： b.bIrA T.r.SEKHAr Department of Mathematics National Institute of Science and Technology Department of Mathematics Indian Institute of Technology Kharagpur

In the present paper, Lie group symmetry method is used to obtain some exact solutions for a hyperbolic system of partial differential equations （PDEs）, which governs an isothermal no-slip drift-flux model for multiphase flow problem. Those sym- metries are used for the governing system of equations to obtain infinitesimal transforma- tions, which consequently reduces the governing system of PDEs to a system of ODEs. Further, the solutions of the system of ODEs which in turn produces some exact solutions for the PDEs are presented. Finally, the evolutionary behavior of weak discontinuity is discussed.

关键词： multiphase flow drift-flux models Lie group analysis exact solution weakdiscontinuity

Inhibition of NO emission by adding antioxidant mixture in Jatropha biodiesel on the performance and emission characteristics of a C.I. engine

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Frontiers in Energy 2015年第2期9卷 238-245页

作者： A. PrAbU r. b. ANAND Department of Mechanical Engineering National Institute of Technol-ogy Tiruchirappalli 620015 India

In this paper, the effect of adding an antiox- idant mixture in Jatropha biodiesel as fuel, in a single cylinder, direct injection compression ignition engine was experimentally investigated and the level of pollutants in the exhaust and performance characteristics of the engine were analyzed. Nine test fuels were prepared with three antioxidants, namely, Suecinimide （C4H5NO2）, N,N-dimethyl-p-phenylenediamine-dihydrochloride （C8H14C12N2）, and N-phenyl-p-phenylenediamine （C6H5NHC6H4NH2） added to neat biodiesel at 500 parts per million （ppm）, 1000ppm and 2000ppm and the observed experimental results were compared with those of neat biodiese! and neat diesel as base fuels. The comparison showed that NO emission was reduced drastically for the test fuels with the antioxidant addition of 2000ppm. The maximum reduction of 10% of NO emission was observed for the antioxidant mixture in neat biodiesel, with a slight increase in unburned HC, CO and smoke opacity. In addition, the obtained experimental results reveal that the addition of two antioxidants as mixture in neat biodiesel caused improved NO emission reduction for all test fuels.

关键词： NO emission antioxidants Succinimide,N,N-dimethyl-p-phenylenediamine-dihydrochloride N-phenyl-p-phenylenediamine

The response of temperature and hydrostatic pressure of zinc-blende Ga_xIn_(1-x)As semiconducting alloys

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Chinese Physics b 2012年第12期21卷 327-334页

作者： A.r.Degheidy E.b.Elkenany Department of Physics Faculty of ScienceMansoura University

The electronic band structure of GaxIn1-xAs alloy is calculated by using the local empirical pseudo-potential method including the effective disorder potential in the virtual crystal approximation. The compositional effect of the electronic energy band structure of this alloy is studied with composition x ranging from 0 to 1. Various physical quantities such as band gaps, bowing parameters, refractive indices, and high frequency dielectric constants of the considered alloys with different Ga concentrations are calculated. The effects of both temperature and hydrostatic pressure on the calculated quantities are studied. The obtained results are found to be in good agreement with the available experimental and published data.

关键词： temperature hydrostatic pressure to GaxIn1-xAs alloys

Impact analysis of compressor rotor blades of an aircraft engine

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Frontiers of Structural and Civil Engineering 2019年第3期13卷 505-514页

作者： Y b SUDHIr SASTrY b G KIrOS F HAILU r bUDArAPU Department of Aeronautical Engineering Institute of Aeronautical EngineeringDundigalHyderabad 500043India Department of Aeronautical Engineering College of EngineeringDefense UniversityBishoftu 1041Ethiopia School of Mechanical Sciences Indian Institute of Technology BhubaneswarBhubaneswar 752050India

Frequent failures due to foreign particle impacts are observed in compressor blades of the interceptor fighter MIG-23 aircraft engines in the Ethiopian air force,supplied by the Dejen Aviation *** this paper,we made an attempt to identify the causes of failure and hence recommend the suitable materials to withstand the foreign particle *** and stress analysis of one of the recently failed MIG-23 gas turbine compressor blades made up of the following Aluminum based alloys:6061-T6,7075-T6,and 2024-T4,has been performed,apart from the impact analysis of the rotor blades hit by a granite *** numerical results are correlated to the practical *** on the modal,stress and impact analysis and the material properties of the three considered alloys,alloy 7075-T6 has been recommended as the blade material.

关键词： axial flow compressor rotor and stator blades aircraft engine stress and impact analysis aluminum alloys

Injection of N-radicals into Diesel Engine Exhaust Treated by Plasma for Improved NO_x removal: A Feasibility Study

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Plasma Science and Technology 2006年第2期8卷 202-206页

作者： b. S. rAJANIKANTH b. r. SUSHMA Dept. of High Voltage Engineering Indian Institute of Science Bangalore 560012 India

reported in this paper is a feasibility study on the injection of plasma induced N radicals for the abatement of NO and NOx present in the actual diesel exhaust. The radical laden diesel exhaust was further treated by discharge plasma in a dielectric barrier discharge reactor. N radicals were produced in a separate plasma reactor filled with baTiO3 pellets and were then injected into the treatment zone, There was a significant improvement in the efficiency when the radicals were injected compared to that when there was no radical injection. The efficiency of NOx removal at 0 load with plasma alone was 14% whereas with the injection of N radicals it went up to 38%, The results of the experiments conducted at different loads are discussed,

关键词： N-radical diesel engine exhaust NOx removal plasma treatment

Why Geometry radiates: Quantum Gravity as Perspective

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Journal of Modern Physics 2016年第6期7卷 489-500页

作者： r.b.langley Norwich UK

It is reasonably expected 1) that a theory of quantum gravity will unify the extremes of scale currently described by General relativity and quantum mechanics, and 2) that black holes are the crucible from which a theory of quantum gravity will emerge. In perspective, we already have a mechanism that links the local, macroscopic frame with the remote, apparently microscopic frame. A simple mathematical principle acts as a limit on D(n), suggesting a “maximum physical reality”, and that effects which are clearly perspectival at D=3 become “more real” (effectively observer-independent) with each D(n) increment. The model suggests alternative interpretations of gravitation and the quantum, entanglement, space, the Standard Model of particles and interactions, black holes, the measurement problem and the information paradox.

关键词： Quantum Gravity black Holes Entanglement Firewalls Er = EPr Information Paradox