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As-Cast Acicular Ductile Aluminum Cast Iron

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Journal of Iron and steel Research International 2009年第6期16卷 23-28页

作者： s m mostafavi Kashani s m A Boutorabi school of metallurgy and materials Engineering Iran University of Science and Technology

The effects of nickel （2.2 %） and molybdenum （0.6 % ） additions on the kinetics, microstrueture, and mechanical properties of ductile aluminum cast iron were studied under the as-cast and tempered conditions. Test bars machined from cast to size samples were used for mechanical and metallurgical studies. The results showed that adding nickel and molybdenum to the base iron produced an upper bainitic structure, resulting in an increase in strength and hardness. The same trend was shown when the test bars were tempered at 300 ℃in the range of 300 ℃ to 400 ℃. The elongation increased with increasing the temperature from 300 ℃ to 400 ℃. The carbon content of the retained austenite also increased with increasing the temperature. The results also showed that the kinetics, microstructure, and mechanical properties of this iron were similar to those of Ni-mo alloyed silicon ductile iron.

关键词： ductile aluminum cast iron acicular bainite carbon content retained austenite

Head-on collision between single-and multi-soliton heavy ion acoustic waves in multi-ion plasmas

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Plasma science and Technology 2019年第9期21卷 58-72页

作者： m s ALAm m R TALUKDER Department of mathematics Chittagong University of Engineering and Technology Chittagong-4349 Bangladesh Plasma science and Technology Lab Department of Electrical and Electronic Engineering University of Rajshahi Rajshahi-6205 Bangladesh

Head-on collisions among the single-and multi-soliton’s heavy ion acoustic waves(HIAWs) of multi-ion plasma are studied. The plasma consists of adiabatic positively charged inertial heavy ions, Boltzmann energy distributed light ions and kappa energy distributed electrons. The extended poincaré-Lighthill-Kuo(e PLK) method is applied for the derivation of two-sided Korteweg–de Vries(KdV) equations(KdVEs). The KdV single-soliton solutions(KdVsss) are determined using the hyperbolic secant method and the KdV multi-soliton solutions(KdVmss)are obtained using the Hirota method. The effects of superthermality of electrons, temperature ratios of electron to light ion and heavy ion to electron, and the density ratio of electron to heavy ion on phase shifts are investigated for the head-on collisions between two-soliton HIAWs. The effects of plasma parameters on angular frequency, phase speed, production of multi-soliton structures, and the head-on collisions among single-, double-, triple-, quadruple-, and quintuplesolitons are also studied.

关键词： HIAWs multi-soliton kappa-distribution ePLK method Hirotta's method multi-ion

Calculation and Analysis of Velocity and Viscous Drag in an Artery with a Periodic Pressure Gradient

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Chinese Journal of mechanical Engineering 2012年第4期25卷 715-721页

作者： ALIZADEH m sEYEDPOUR s m mOZAFARI V BABAZADEH shayan s Department of mechanical Engineering Iran University of Science and TechnologyTehranIran Department of mechanical Engineering Islamic Azad University of Science and ResearchTehranIran Department of mechanical Engineering Tarbiat Modares UniversityTehranIran

Blood as a fluid that human and other living creatures are dependent on has been always considered by scientists and *** changes in blood pressure and its normal velocity can be a sign of a *** significant in blood fluid＇s mechanics is Constitutive equations and finding some relations for analysis and description of drag,velocity and periodic blood pressure in *** this paper,by considering available experimental quantities,for blood pressure and velocity in periodic time of a thigh artery of a living dog,at first it is written into Fourier series,then by solving Navier-stokes equations,a relation for curve drawing of vessel blood pressure with rigid wall is *** in another part of this paper,vessel wall is taken in to consideration that vessel wall is elastic and its pressure and velocity are written into complex Fourier *** this case,by solving Navier-stokes equations,some relations for blood velocity,viscous drag on vessel wall and blood pressure are *** this study by noting that vessel diameter is almost is large（3.7 mm）,and blood is considered as a Newtonian ***,available experimental quantities of pressure with obtained curve of solving Navier-stokes equations are *** blood analysis in rigid vessel,existence of 48% variance in pressure curve systole peak caused vessel blood flow analysis with elastic wall,results in new relations for blood flow *** Resultant curve is obtained from new relations holding 10% variance in systole peak.

关键词： artery newtonian fluid rigid & elastic wall newtonian fluid

self-seeded quantum-dash laser based 5 m–128 Gb/s indoor free-space optical communication

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Chinese Optics Letters 2017年第12期15卷 38-41页

作者： m.A.shemis A.m.Ragheb E.Alkhazraji m.A.Esmail H.Fathallah s.Alshebeili m.Z.m.Khan Optoelectronics Research Laboratory Electrical Engineering DepartmentKing Fahd University of Petroleum and Minerals KACsT-TIC in Radio Frequency and Photonics for the e-society (RFTONICs) Department of Electrical and Electronics Engineering Technology Jubail Industrial College Computer Department of the College of science of Bizerte University of Carthage Electrical Engineering Department King Saud University

We demonstrate an indoor 5 m free-space optical wireless coherent communication in mid L-band（1606.7 nm）by employing a tunable self-seeded InAs/InGaAlAs/InP quantum-dash（Qdash） laser as a subcarrier generator for 128 Gb/s dual-polarization quadrature phase shift keying（DP-QPsK） modulation signal. The bare Qdash laser diode displays ~6 nm self-locked Fabry-Perot mode tunability with ~30 dB side mode suppression ratio（smsR） and ~10 dBm mode power across the tuning range, thus encompassing ~10 modes with an achievable capacity of 1.28 Tb/s（10 × 128 Gb∕s） and potentially qualifying the source requirements for future access networks.

关键词： FsO Gb/s indoor free-space optical communication self-seeded quantum-dash laser based 5 m

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Analysis of mode Ⅲ crack perpendicular to the interface between two dissimilar strips

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Acta mechanica sinica 2008年第4期24卷 433-438页

作者： m.s.matbuly Department of Engineering mathematics and Physics Faculty of Engineering Zagazig University P.O. 44519 Zagazig Egypt

The present work is concerned with the problem of mode Ⅲ crack perpendicular to the interface of a bi-strip composite. One of these strips is made of a functionally graded material and the other of an isotropic material, which contains an edge crack perpendicular to and terminating at the interface. Fourier transforms and asymptotic analysis are employed to reduce the problem to a singular integral equation which is numerically solved using Gauss-Chebyshev quadrature formulae. Furthermore, a parametric study is carried out to investigate the effects of elastic and geometric characteristics of the composite on the values of stress intensity factor.

关键词： Composite · Interface · Perpendicular crack ·Anti-plane shear stress · Fourier transform. singular integral equation

Engineering of efficient visible light photocatalysts:Ti_(1-x+y)Cu_(x)La_(y)O_(2)(x=0.03;y=0,0.005,0.01) compositions

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Journal of Rare Earths 2024年第3期42卷 497-505,I0003页

作者： s.m.Yakout A.m.Youssef Inorganic Chemistry Department National Research Centre(NRC)El Buhouth StDokkiCairo12622Egypt

In dye-photocatalysis, widening the wavelengths absorption range of catalysts as well as aborting the recombination of the photoexcited charge carriers(electrons-holes pairs) are of paramount *** the current study, we report the photocatalytic characteristics of four compositions composed of TiO_(2),Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders for two harmful dyes(Congo red and methylene blue). The X-ray diffraction technique verified the configuration of mixed anatase and rutile phases in pure TiO_(2)and Ti_(0.97)Cu_(0.03)O_(2)powders while Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders possess anatase phase only. The changes of the band gap structure and dimensions of the unit cell volume of TiO_(2)confirm the substitution of Ti^(4+)sites by Cu^(2+)and La^(3+)ions. Remarkable widening of wavelengths absorption with formation of long absorption tails were found in TiO_(2)(3.13 e V) through insertion of La^(3+)plus Cu^(2+)ions. Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)samples exhibit a visible light band gap of 2.3 and 2.7 e V, respectively. Based on sEm images, incorporation of Cu^(2+)and La^(3+)ions influences the surface morphology of TiO_(2). The resulting Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders present enhanced photocatalytic activity towards Congo red dye degradation compared to pure one under natural solar spectrum. The best Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst exhibits superior photocatalytic activity of 96% for 10 ppm CR dye in 20 min as well as above average photocatalytic efficiency of 63% for 30 ppm CR dye in 120 min. As well, it showed acceptable photodegradation activity of 52% for 30 ppm mB solution in 140 min of sunlight irradiation. The heightened photodegradation efficiency of Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst can be clarified in terms of higher ch

关键词： semiconductor TiO_(2) Rare earths Congo red methylene blue solar spectrum Photodegradation

Hydromagnetic oscillatory Couette flow in rotating system with induced magnetic field

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Applied mathematics and mechanics(English Edition) 2014年第10期35卷 1331-1344页

作者： G.s.sETH s.m.HUssAIN s.sARKAR Department of Applied mathematics Indian School of Mines Department of mathematics O.P.Jindal Institute of Technology

This paper presents a study of hydromagnetic Couette flow of an incompress- ible and electrically conducting fluid between two parallel rotating plates, one of which is oscillating in its own plane. A uniform transverse magnetic field is used, and the induced magnetic field is taken into account. The exact solution to the governing equations is obtained in a closed form. The solution to the problem in the case of vanishing and small finite magnetic Prandtl numbers is also derived from the general solution. The asymp- totic behavior of the solution for large values of the frequency parameter is analyzed to gain some physical insights into the flow pattern. Expressions for the shear stress at both the oscillatory and stationary plates due to primary and secondary flows and mass flow rate in the primary and secondary flow directions are also obtained. The results of the fluid velocity and the induced magnetic field are presented. The shear stresses on the plates due to the primary and secondary flows and the corresponding mass flow rates are presented in a tabular form.

关键词： magnetic interaction parameter Ekman number frequency parameter,hydromagnetic stokes-Ekman boundary layer magnetic diffusion boundary layer

Cost-effective integrated strategy for the fabrication of hard-magnet barium hexaferrite powders from low-grade barite ore

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International Journal of minerals,metallurgy and materials 2016年第9期23卷 991-1000页

作者： m.m.s.sanad m.m.Rashad Central metallurgical R & D Institute

Ultrafine barium hexaferrite（BaFe12O19） powders were synthesized from the metallurgical extracts of low-grade Egyptian barite ore via a co-precipitation route. Hydrometallurgical treatment of barite ore was systematically studied to achieve the maximum dissolution efficiency of Fe（～99.7%） under the optimum conditions. The hexaferrite precursors were obtained by the co-precipitation of Bas produced by the reduction of barite ore with carbon at 1273 K and then dissolved in diluted HCl and FeCl3 solution at pH 10 using NaOH as a base; the product was then annealed at 1273 K in an open atmosphere. The effect of Fe^3＋/Ba^2＋ molar ratio and the addition of hydrogen peroxide（H2O2） on the phase structure, crystallite size, morphology, and magnetic properties were investigated by X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. single-phase BaFe（12）O（19） powder was obtained at an Fe^3＋/Ba^2＋ molar ratio of 8.00. The formed powders exhibited a hexagonal platelet-like structure. Good maximum magnetization（48.3 A×m^2×kg^–1） was achieved in the material prepared at an Fe^3＋/Ba^2＋ molar ratio of 8.0 in the presence of 5% H2O2 as an oxidizer and at 1273 K because of the formation of a uniform, hexagonal-shaped structure.

关键词： chemical process barite ore treatment characterization magnetic properties ferrites

Catalytic effect of srTiO_3 on the hydrogen storage behaviour of mgH_2

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Journal of Energy Chemistry 2019年第1期28卷 46-53页

作者： m.s.Yahya m.Ismail school of Ocean Engineering University Malaysia Terengganu

The effects of sr TiO_3 on the hydrogen storage properties of mgH_2 have been studied for the first *** onset dehydrogenation temperature of the mgH_2-10 wt% srTiO_3 is found to be 275 ℃, which is 55 ℃ lower as compared to the as-milled mgH_2. The composite is able to absorb 4.3 wt% of hydrogen in 60 min instead of 1.1 wt% for the as-milled mg H_2. meanwhile, the composite is able to release 5.3 wt% of hydrogen in 17 min compared to 1.9 wt% by the as-milled mg H_2 at 320 ℃. The calculated Eaof the mg H_2-10 wt% srTiO_3 is 109 k J/mol, which is 26.3 kJ/mol lower than the calculated Eaof the as-milled mgH_2. The sr TiO_3 is not decomposed during the ball milling and the re/dehydrogenation processes. The catalytic effect shown by the srTiO_3 is owing to its ability to change the physical structure of the mgH_2 particles during the ball milling process.

关键词： Hydrogen storage magnesium hydride Catalytic effect sorption properties