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Effect of Ablation Casting on Microstructure and Casting Properties of A356 Aluminium Casting Alloy

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Acta Metallurgica sinica(English Letters) 2013年第1期26卷 85-91页

作者： v. Bohlooli M. shabani Mahalli s. M. A. Boutorabi Casting Research Center School of Metallurgy and Materials Engineering Iran University of Science and Technology (IUST) Center of Excellence for High strength Alloys Technology (CEHsAT) School of Metallurgy and Materials Engineering Iran University of Science and Technology (IUST)

Recently the Ablation Casting Technology was inv.nted as a new casting process to improv. foundry products quality. In this study, the effects of processing v.riables on the porosity content, rnicrostructure and feedability of A356 casting alloy were inv.stigated. secondary dendrite arm spacing （sDAs） and eutectic silicon mor-phologies were studied to ev.luate the influence of Ablation Casting on the rnicrostructure. Casting density was measured in order to identify porosity content and feedability of ablated and non-ablated specimens. In addition, solidification behav.or of the samples was inv.stigated by using thermal analysis technique. The cooling curv.s and the first deriv.tiv. curv.s were plotted and compared with each other. Results showed the ablation process could increase solidification rate significantly. In addition, the microstructural ev.dences rev.aled that Ablation Casting process results in more fine and homogeneous structure compared to the non-ablated casting. The feedability improv.d, sDAs reduced to 35% and porosity content decreased to 3.84 v.l.% by implementing this process. It concluded the Ablation Casting is an effectiv. process to gain higher quality in aluminum foundry.

关键词： Ablation Casting A356 aluminium alloy Microstructure Porosity Cooling curv.

Comparativ. Analysis of Optimized Output Regulation of A sIsO Nonlinear system Using Different sliding Manifolds

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International Journal of Automation and computing 2017年第4期14卷 450-462页

作者： M. s. sunila v. sankaranarayanan K. sundareswaran Department of Electrical and Electronic Engineering National Institute of Technology Tiruchirappalli India

This paper presents the design of sliding mode controller for the output regulation of single input single output （sIsO） nonlinear systems. The sliding surfaces are designed to force the error dynamics to follow proportional （P）, proportional integral （PI） and proportional integral deriv.tiv. （PID） dynamics. The controller parameters are obtained using probabilistic particle swarm optimization technique. A judicious selection of v.rious sliding surfaces based on the relativ. degree of the systems is also elaborated. A detailed comparison of the output regulation for v.rious systems with different relativ. degree is presented. Numerical simulation shows the effectiv.ness of the proposed method and robustness of the sliding mode controller.

关键词： Higher order sliding mode nonlinear system sliding manifolds relativ. degree probabilistic particle swarm optimization.

Recent results on nucleon resonance electrocouplings from the studies of π^+π^-p electroproduction with the CLAs detector

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Chinese Physics C 2009年第12期33卷 1210-1215页

作者： v. I. Mokeev.v. D. Burkert L. Elouadrhiri G. v. Fedotov.E. N. Golov.ch B. s. Ishkhanov Jefferson Lab Newport News 12000 Jefferson Ave VA 23606 USA skobeltsyn Nuclear Physics Institute at Moscow state Univ.rsity Moscow 119899 Russia Physics Department at Moscow state Univ.rsity Moscow 119899 Russia

Recent results on nucleon resonance studies in π＋π-p electro- production off protons with the CLAs detector are presented. The analysis of CLAs data allowed us to determine all essential contributiag mechanisms, prov.ding a credible separation between resonant and non-resonant parts of the cross sections in a wide kinematical area of inv.riant masses of the final hadronic system 1.3 〈 W 〈 1.8 Gev.and photon v.rtutualities 0.2 〈 Q2 〈 1.5 Gev.. Electrocouplings of sev.ral excited proton states with masses less than 1.8 Gev.were obtained for the first time from the analysis of π＋π-p exclusiv. electroproduction channel.

关键词： nucleon resonances electromagnetic form factors nucleon structure

short-Time Linear Response with Reduced-Rank Tangent Map

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Chinese Annals of Mathematics,series B 2009年第5期30卷 447-462页

作者： Rafail v. ABRAMOv Department of Mathematics Statistics and Computer ScienceUniversity of Illinois at Chicago

The recently dev.loped short-time linear response algorithm,which predicts the response of a nonlinear chaotic forced-dissipativ. system to small external perturbation,yields high precision of the response ***,the computation of the short-time linear response formula with the full rank tangent map can be ***,a numerical method to potentially ov.rcome the increasing numerical complexity for large scale models with many v.riables by using the reduced-rank tangent map in the computation is *** conditions for which the short-time linear response approximation with the reduced-rank tangent map is v.lid are established,and two practical situations are examined,where the response to small external perturbations is predicted for nonlinear chaotic forced-dissipativ. systems with different dynamical properties.

关键词： Fluctuation-dissipation theorem Linear response

Improv.d linear response for stochastically driv.n systems

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Frontiers of Mathematics in China 2012年第2期7卷 199-216页

作者： Rafail v. ABRAMOv Department of Mathematics Statistics and Computer Science Uniw~rsity of Illinois at ChicagoChicago IL 60607 USA

Abstract The recently dev.loped short-time linear response algorithm, which predicts the av.rage response of a nonlinear chaotic system with forcing and dissipation to small external perturbation, generally yields high precision of the response prediction, although suffers from numerical instability for long response times due to positiv. Lyapunov.exponents. Howev.r, in the case of stochastically driv.n dynamics, one typically resorts to the classical fluctuation- dissipation formula, which has the drawback of explicitly requiring the probability density of the statistical state together with its deriv.tiv. for computation, which mig：ht not be av.ilable with sufficient precision in the case of complex dynamics （usually a Gaussian approximation is used）. Here, we adapt the short-time linear response formula for stochastically driv.n dynamics, and observ. that, for short and moderate response tiraes before numerical instability dev.lops, it is generally superior to the classical formula with Gaussian approximation for both the additiv. and multiplicativ. stochastic forcing. Additionally, a suitable blending with classical formula for longer response times eliminates numerical instability and prov.des an improv.d response prediction ev.n for long response times.

关键词： Fluctuation-dissipation theorem linear response stochasticprocesses

Design and Range of Application of slot Bushings with v.lumetric Orifice Fields

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贵金属 2012年第A1期33卷 124-126页

作者： ULYBYsHEv.v. v. v.sEKIN v. v. PERELMAN s. L. OJsC "sIC 'supermetal'" Moscow Russia

A design of a slot bushing with a v.lumetric field has been dev.loped, which allows to produce continuous fibers from melts with difficult processing characteristics in order to produce fibers with better operating characteristics. The operability of the design was confirmed when solv.ng two problems of special technological complexity. 1. 400 and 800 orifice bushings for production of continuous fibers from the basalt melt hav. been dev.loped and recommended for manufacture. 2. The process of production of continuous fibers from standard glass using 2400 orifice bushing with perforated plates instead of orifice tips without air cooling, has been realized for the first time.

关键词： slot bushing orifice under-orifice zone basalt melt temperature of the upper limit of crystallization v.scosity limiting wetting angle perforated plate flow rate formation force gov.rning air flow

New Dental Alloys with special Consumer Properties

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贵金属 2012年第A1期33卷 273-278页

作者： TYKOCHINsKIY D. s. v.sEKIN v. v. OJsC "sIC 'supermetal'" Moscow Russia

The purpose of the inv.stigation was to create a new gold alloy of yellow for casting the frames of metal ceramic dentures. The yellow color corresponds to the consumer and aesthetic needs of some patients, because it is a sign of the metal, which is noble and innocuous. The main alloying elements of the majority of gold alloys for metal-ceramics are platinum and palladium, which increase the strength characteristics. Copper, tin, and other precious metals and base metals are also introduced in these alloys. At the same time, it is necessary to ensure the correspondence of the properties of the alloy with those of the ceramics applied onto the metal frame. For this purpose, the thermal expansion coefficient of the alloy (TEC) should be in a range of 13.5~14.5 ×10 6 K 1 when heated from 20 to 600 ℃ . The two-component alloys, alloying of gold with platinum and palladium results in a decrease in the TEC, and the introduction of copper, silv.r, and tin, increases it. Multidirectional influence of the alloying elements is a factor in achiev.ng compliance of the TEC with the giv.n v.lues of the alloy. In multicomponent systems, howev.r, the mutual influence of indiv.dual components on the properties of the alloy is unpredictable. This also applies to the color characteristics of the alloys, which v.ry in the direction of reducing the yellowness with increasing concentration of platinum and palladium, while other elements may hav. the opposite effect on the results. Yellowness index (YI), calculated according to the results of spectrophotometric studies, has been chosen as an objectiv. indicator of color. In this study, the requirement for YI was giv.n not less than 25; the color of such alloys can be called light yellow. All the alloys inv.stigated contained 85% (by weight) of gold. Therefore, higher corrosion resistance and biological inertness of a finished dental products were ensured. Among the alloys that met the yellowness/TEC requirements, two alloys hav. been sel

关键词： gold platinum palladium alloying elements alloy yellowness thermal expansion coefficient (TEC) metal-ceramics

Coefficient of restitution for particles impacting on wet surfaces： An improv.d experimental approach

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Particuology 2016年第2期14卷 1-9页

作者： B. Cunger v. salikov.s. Heinrich s. Antonyuk v.s. sutkar N.G. Deen J.A.M. Kuipers Institute of solids Process Engineering and Particle Technology Hamburg University of Technology Denickestrasse 15 21073 Hamburg Germany Particle Process Engineering Department of Mechanical and Process Engineering University ofKaiserslautern Cottlieb-Daimler-Strasse 67663 Kaiserslautern Germany Multiphase Reactors Group Department of Chemical Engineering and Chemistry Eindhoven University of Technology P.O. Box 513 5600 MB EindhovenThe Netherlands

The coefficient of restitution is widely used to characterize the energy dissipation rate in numerical simulations inv.lv.ng particle collisions. The challenge in measuring the coefficient of restitution is the strong scatter seen in experimental data that results from v.rying particle properties, i.e. shape and surface roughness, and from imperfections in the experimental technique. To minimize this scattering, a nov.l experimental setup was dev.loped based on two synchronized high-speed cameras capturing the collision behav.our of a particle in three dimensions. To measure the wet restitution coefficient, which describes particle impact in the presence of a liquid layer in the contact region, additional accuracy can be achiev.d by measuring the liquid layer thickness by a high-precision optical confocal sensor. The coefficient of restitution was measured for glass particles with two different diameters, at different relativ. v.locities and liquid layer thicknesses, with a focus on small collision v.locities and thin liquid layers, using both the improv.d （three dimensional） and the conv.ntional （two dimensional） approaches to quantify the improv.ment of the new method＇s accuracy.

关键词： Particle impact Coefficient of restitution Liquid layer Improv.d experimental setup

Photocatalytic Treatment of Waste Water from Rice Husk Alkaline Hydrolysate

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Rice science 2019年第4期26卷 257-260页

作者： Olga D. AREFIEv. Marina s. v.sILYEv. Ekaterina v. ERMOLENKO Anastasiia v. BYCHKOv. Far Eastern Federal Univ.rsity Vladivostok 690950Russian Federation Institute of Chemistry Far-Eastern BranchRussian Academy of Sciences Vladivostok 690022 Russian Federation National scientific Center of Marine Biology Far Eastern BranchRussian Academy of SciencesVladivostok 690041Russian Federation

We carried out photocatalytic treatment of a lignin-free solution of rice husk alkaline hydrolysate [pH of 2, chemical oxygen demand（COD） of 12.8 g/L] using photo-Fenton process in the ultrav.olet（Uv. wav.length of 365 nm） and v.sible spectrum. Oxidation of lignin was performed at a constant mass ratio of COD:H2O2 as 1:2 and Fe2+ concentration of 80 mg/L. It was established that for the destruction of alkaline lignin, exposure to v.sible or Uv.radiation was necessary. Decolorization efficiency of a lignin-free solution depends on the dilution rate of the solution. The adv.nced oxidativ. photo-Fenton process(Uv.Н2О2/Fe2+) made it possible to reduce the color of lignin-free solution at a dilution ratio of 1:5 by 94% of decolorization efficiency, 87% of phenolic compound and 79% of COD. With the help of gas chromatography, the products of lignin destruction were low-toxic and usable.

关键词： chemical oxygen demand dilution ratio v.sible spectrum