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Effect of Plastic Deformation on Magnetic Properties of Fe-40%Ni-2%Mn Austenitic Alloy

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Journal of Iron and steel Research International 2007年第4期14卷 56-60页

作者： selva Büyükakka■ H Aktas s Akturk Physics Department Nigde UniversityNigde 51100NigdeTurkey Physics Department Kirikkale UniversityYahsihan 71450KirikkaleTurkey

The effects of plastic deformation on the magnetic properties of austenite structure in an Fe-40% Ni-2 % Mn alloy is investigated by using Mossbauer spectroscopy and Differential scanning Calorimetry （DsC） techniques The morphology of the alloy has been obtained by using scanning Electron Microscopy （sEM）. The magnetic behaviour of austenite state is ferromagnetic. After plastic deformation, a mixed magnetic structure including both paramagnet- ic and ferromagnetic states has been obtained at the room temperature. The volume fraction changes, the effective hyperfine fields of the ferromagnetic austenite phase and isomery shift values have also been determined by Mossbauer spectroscopy. The Curie point （Tc） and the Neel temperature （TN） have been investigated by means of DsC system for non-deformed and deformed Fe-Ni-Mn alloy. The plastic deformation of the alloy reduces the TN and enhances the paramagnetic character of austenitic Fe-Ni-Mn alloy.

关键词： Mossbauer spectroscopy differential scanning calorimetry (DsC) scanning electron microscopy (sEM) plastic deformation magnetically ordered material ferromagnetic austenite

Mathematical Model Development of Raceway Parameters and Their Effects on Corex Process

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Journal of Iron and steel Research International 2011年第5期18卷 20-24页

作者： s C Barman K P Mrunmaya M Ranjan Arcelor Mittal Design and Engineering Centre JsW steel Ltd Vijayanagar Works

Corex is an alternative ironmaking process and raceway is one of the important areas to maintain the stability of the furnace. The raceway parameters are well established for blast furnace operation. But for Corex process,it has not yet been established and optimized. Thus,a mathematical model was developed to determine various raceway parameters such as RAFT （raceway adiabatic flame temperature）,tuyere gas velocity and kinetic energy. The model provides an idea about the raceway geometry,zone temperature and kinetic energy accumulated in tuyere gas. Besides,all the raceway parameters have been analyzed to find out their effects on the Corex process. It is found that RAFT influences the gasification reaction kinetics and higher RAFT generates more CO in reduction gas,which improves the metallisation degree of the DRI in shaft. It is also found that increased gas velocity and kinetic energy generate more fines and demand more coke to maintain char bed permeability. High coke rate increases the production cost and lowers the production of hot metal.

关键词： Corex raceway RAFT reducing gas metallisation

skew Pairs of Idempotents in Transformation semigroups

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Acta Mathematica sinica,English series 2006年第6期22卷 1705-1714页

作者： T.s.BLYTH M.H.ALMEIDA sANTOs Mathematical Institute University of St Andrews Departamentode Matemática F.C.T.Universidade Nova de Lisboa

An ordered pair （e, f） of idempotents of a regular semigroup is called a skew pair if ef is not idempotent whereas fe is idempotent. We have shown previously that there are four distinct types of skew pairs of idemp... 详细信息

关键词： full transformation semigroups idempotents skew pairs

Transient mixed convection flow arising due to thermal and mass diffusion over porous sensor surface inside squeezing horizontal channel

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Applied Mathematics and Mechanics(English Edition) 2013年第1期34卷 97-112页

作者： M.MAHMOOD s.AsGHAR M.A.HOssAIN Department of Mathematics COMSATS Institute of Information TechnologyPark RoadChak ShahzadIslamabad 44000Pakistan

The double diffusion effect on the mixed convection flow over a horizontal porous sensor surface placed inside a horizontal channel is analyzed. With the appropriate transformations, the unsteady equations governing the flow are reduced to non-similar boundary layer equations which are solved numerically for the time-dependent mixed convection parameter. The asymptotic solutions are obtained for small and large values of the time-dependent mixed convection parameter. The results are discussed in terms of the skin friction, the heat transfer coefficient, the mass transfer coefficient, and the velocity, temperature, and concentration profiles for different values of the Prandtl number, the schmidt number, the squeezing index, and the mixed convection parameter.

关键词： squeezed flow mass transfer mixed convection horizontal surface

PREPARATION AND ANALYsIs OF Ni-P-Zn ELECTROLEss DEPOsITION FROM ALKALI BATH

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Acta Metallurgica sinica(English Letters) 2005年第3期18卷 204-208页

作者： Y.s.Huang F.Z.Cui DepartmentofMaterialsscience＆Engineering TsinghuaUniversityBeijing100084China／／InstituteofBiomechanicsSouthChinaUniversityofTechnologyGuangzhou510641China DepartmentofMaterialsscience＆Engineering TsinghuaUniversityBeijing100084China

Electroless Ni-P-Zn alloys deposited from alkali bath were investigated in this paper. The deposition bath contained nickel sulfate, zinc chloride and hypophosp hate. The process parameters, such as temperature, pH and zinc salt concentratio n were presented and discussed. The microstructure of the coatings was studied b y XRD and sEM. The cathode glowing discharge characters of Ni-P-Zn depositions w ere studied with luminous Neon lamps. Electrodes deposited by electroless Ni-P a lloys were apt to sputter during luminous working hours. Electroless Ni-P-Zn dep ositions improved the discharge characters of the electrodes. With the concentra tion of zinc in the deposition rising to 4wt%, electrode sputter was largely res trained. The thickness of the deposition also influenced the discharge character s of the electrode. To avoid electrode sputter, the concentration of zinc has to rise with the thickness of the depositions.

关键词： electroless Ni-P-Zn alloy electrode sputter cathode glowing Discharge

Analysis and formulation of spur gear stresses with different tip modifications

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Journal of Central south University 2019年第9期26卷 2368-2378页

作者： A.MAPER s.KARUPPANAN s.s.PATIL Department of Mechanical Engineering Universiti Teknologi PETRONASBandar Seri Iskandar 32610Perak Darul RidzuanMalaysia Department of Mechanical Engineering Manipal University JaipurJaipur 303007RajasthanIndia

spur gears are widely used in the power transmission mechanism of several *** to the transmitted torque,spur gears experience high stresses which could cause gear tooth failure by surface pitting or root *** relief and other gear profile modification have been considered for reducing the induced stresses in the gear *** this work,the influence of tip relief on stresses on a pair of identical spur gear was analyzed using commercial FEA software ANsYs,and formulae for estimating contact and bending stresses were *** cases of gear sets were analyzed;a non-modified pair and another two sets with linear and parabolic tip relief *** non-modified gear set frictionless contact stress was validated against the calculated AGMA pitting resistance,Hertzian contact stress and a reported contact stress value in the *** four methods agreed well with each ***,bending stress was also compared with the AGMA bending strength and Lewis bending stress for ***,friction coefficient was varied from 0.0 to 0.3 with increment of *** gear contact stress increased up to 11%relative to the frictionless case,whereas bending stress decreased by 6%.Linear tip relief modification was carried out for increasing normalised tip relief values of 0.25 to 1.0 with increment of *** gear frictionless contact and bending stresses decreased by a maximum of 4%and 2%,*** contact stress increased by up to 7.1%and the bending stress is almost identical with the frictionless *** tip relief was also carried out with similar normalised tip relief *** contact stress decreased by 5%while frictional contact stress increased by up to 11.5%and the bending stress is also almost identical with the frictionless ***,four formulae were introduced for estimating the contact and bending stresses for a tip modified spur gear.

关键词： gear stresses friction linear tip relief parabolic tip relief

Central serotonergic and noradrenergic receptors in functional dyspepsia

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World Journal of Gastroenterology 2006年第17期12卷 2681-2687页

作者： s O'Mahony TG Dinan PW Keeling AsB Chua Department of Psychiatry and Alimentary Pharmabiotic Centre University College Cork Ireland Department of Medicine Trinity College Dublin Ireland Ipoh Gastro Centre Ipoh PerakMalaysia

Functional dyspepsia is a symptom complex characterised by upper abdominal discomfort or pain, early satiety, motor abnormalities, abdominal bloating and nausea in the absence of organic disease. The central nervous system plays an important role in the conducting and processing of visceral signals. Alterations in brain processing of pain, perception and affective responses may be key factors in the pathogenesis of functional dyspepsia. Central serotonergic and noradrenergic receptor systems are involved in the processing of motor, sensory and secretory activities of the gastrointestinal tract. Visceral hypersensitivity is currently regarded as the mechanism responsible for both motor alterations and abdominal pain in functional dyspepsia. some studies suggest that there are alterations in central serotonergic and noradrenergic systems which may partially explain some of the symptoms of functional dyspepsia. Alterations in the autonomic nervous system may be implicated in the motor abnormalities and increases in visceral sensitivity in these patients. Noradrenaline is the main neurotransmitter in the sympathetic nervous system and again alterations in the functioning of this system may lead to changes in motor function. Functional dyspepsia causes considerable burden on the patient and society. The pathophysiology of functional dyspepsia is not fully understood but alterations in central processing by the serotonergic and noradrenergic systems may provide plausible explanations for at least some of the symptoms and offer possible treatment targets for the future.

关键词： Functional dyspepsia serotonin Nor- adrenaline Gastrointestinal disorders

Periodic Algebras Generated by Groups

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Algebra Colloquium 2015年第4期22卷 541-554页

作者： s. Albeverio B.A. Omirov U.A. Rozikov Institut fur Angewandte Mathematik and HCM Universitat Bonn Bonn Germany Institute of Mathematics 29 Do'rmon Yo'li str. 100125 Tashkent Uzbekistan

We consider algebras with basis numerated by elements of a group G. We fix a function f from G × G to a ground field and give a multiplication of the algebra which depends on f. We study the basic properties of such algebras. In particular, we find a condition on f under which the corresponding algebra is a Leibniz algebra. Moreover, for a given subgroup G of G we define a G-periodic algebra, which corresponds to a G-periodic function f, we establish a criterion for the right nilpotency of a G-periodic algebra. In addition, for （7 = Z we describe all 2Z- and 3Z-periodic algebras. some properties of nZ-periodic algebras are obtained.

关键词： periodic algebra Leibniz algebra group

First-line eradication of H pylori infection in Europe:A metaanalysis based on congress abstracts,1997-2004

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World Journal of Gastroenterology 2006年第33期12卷 5311-5319页

作者： Gyrgy M Buzás Jolán Józan Ferencváros Health Center Gastroenterology Budapest Hungary National Institute of Traumatology Department of Experimental Medicine Budapest Hungary

AIM： To meta-analyse the European abstracts presented between 1997-2004 at the European Hpylori study Group, United European Gastroenterology Week meetings and World Congresses of Gastroenterology. METHODs： The abstracts of randomized/controlled prospective studies were classified into groups based on first-line eradication schedules. The quality of the abstracts was checked by a validated score system. The pooled eradication rates （PER） and combined odds ratios （OR） were calculated and compared with the published meta-analyses. REsULTs： The PER of proton pump inhibitor-based （PPI） one week triple therapies was 81.4% （confidence interval, 95% CI： 78.5-84.5）. Ranitidine bismuth citratebased （RBC） triple regimens have an efficiency rate of 78.5% （95% CI： 70.5%-84.3%）（P = 0.28 vs PPI）. The OR for PPI effect vs RBC regimens was 1.1 （95% CI： 0.92-1.30）. H2 receptor antagonist-based triple therapies achieved 64.1% （95% CI： 52.6-75.6）（P = 0.02 〈 0.05 vs PPI）, the OR vs PPI regimens was 1.55 （95% CI： 0.72-3.78）. PPI-based double combinations were less efficient than triple regimens （PER： 55.0%, OR： 4.90, 95% CI： 2.36-9.70）. Quadruple regimens were successful in 82.6% （95% CI： 76.0-89.7）, the OR vs triple therapies was 0.80 （0.62-1.03）. Clarithromycin ＋ amoxicillin or nitroimidazole combinations were efficient in 80.5% （95% CI： 77.2-84.2） and 83.8% （95% CI： 81.7-85.9）, respectively. Amoxicillin ＋ nitromidazole therapies eradicated the infection in 73.5% （66.6-78.5）（P = 0.01 〈 0.05 vs clarithromycin-based regimens）. CONCLUsION： PPI/RBC-based triple therapies achieved comparable results with the meta-analyses. H2-receptor antagonists and PPI-based double combinations were less efficient. Triple and quadruple regimens were equally effective. Clarithmmycin ＋ either amoxicillin or nitroimidazole containing regimens were more effective than amoxicillin ＋ nitroimidazole combinations. High quality congress abstracts constitutes a valuable pool of data which is suitable for

关键词： Antimicrobials Eradication H pylori Protonpump Inhibitors Ranitidine bismuth citrate