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Effects of Mo and Zr on Microstructure,Mechanical Properties and Wear Resistance of Fe-Al Based Alloys

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Journal of Materials Science & Technology 2008年第3期24卷 309-312页

作者： i.D.yeo H.S.Kim y.G.yoo W.y.Kim Advanced Materials R&D Division Korea Institute of Industrial Technology7-47Songdo-dongYeonsu-gu

in this work the microstructure, mechanical properties and wear resistance of Fe-Al based alloys with various alloying elements were studied. The microstructures were examined by optical and scanning electron microscopy （SEM） equipped with an energy dispersive X-ray spectroscope （EDS）. Two types of alloys were prepared by vacuum arc melting. One is Fe-28Al based alloys （D03 structured） with and without alloying elements such as Mo and Zr. The other one is Fe-35Al based alloys （B2 structured） produced with the same manner. For both types of alloys, Mo addition had found to exhibit an equiaxed microstructure, while dendritic structure was observed to show the effect of Zr addition. These microstructural features were more evinced with increasing content of alloying element. Concerning the mechanical properties and wear resistance, Fe-35Al based alloys were superior to Fe-28Al based alloys over the whole temperature range investigated.

关键词： Fe-Al alloy intermetallic Mechanical properties Wear resistance

Couple stress fluid flow in a rotating channel with peristalsis

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Journal of Hydrodynamics 2018年第2期30卷 307-316页

作者： y.Abd elmaboud Sara i.Abdelsalam Kh.S.Mekheimer Mathematics Department Faculty of Science and Arts Khulais University Of Jeddah Mathematics Department Faculty of Science Al-Azhar University (Assiut Branch) Department of Mechanical Engineering University of CaliforniaRiverside USA Basic Science Department Faculty of Engineering The British University in Egypt Mathematics Department Faculty of Science Al-Azhar University

This article describes a new model for obtaining closed-form semi-analytical solutions of peristaltic flow induced by sinusoidal wave trains propagating with constant speed on the walls of a two-dimensional rotating infinite channel. The channel rotates with a constant angular speed about the z-axis and is filled with couple stress fluid. The governing equations of the channel deformation and the flow rate inside the channel are derived using the lubrication theory approach. The resulting equations are solved, using the homotopy perturbation method（HPM）, for exact solutions to the longitudinal velocity distribution, pressure gradient, flow rate due to secondary velocity, and pressure rise per wavelength. The effect of various values of physical parameters, such as, Taylor＇s number and couple stress parameter, together with some interesting features of peristaltic flow are discussed through graphs. The trapping phenomenon is investigated for different values of parameters under consideration. it is shown that Taylor＇s number and the couple stress parameter have an increasing effect on the longitudinal velocity distribution till half of the channel, on the flow rate due to secondary velocity, and on the number of closed streamlines circulating the bolus.

关键词： Homotopy perturbation method (HPM) couple stress fluid rotating channel peristaltic transport

Systematic experimental study of the temperature dependence of viscosity and rheological behavior of water-based drilling fluids with nano-additives

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Petroleum 2023年第4期9卷 534-544页

作者： A.V.Minakov M.i.Pryazhnikov E.i.Mikhienkova y.O.Voronenkova Siberian Federal University KrasnoyarskRussia Kutateladze institute of Thermophysics SB RASNovosibirskRussia

The paper presents the results of a systematic study of the influence of nano-additives of various concentrations,average sizes and composition on the temperature dependence of the viscosity and rheological behavior of water-based drilling *** compositions of drilling fluids,such as water suspensions of various clay solutions and gammaxan-based polymer solutions,were *** nanoparticles of silicon and aluminum oxides were used as nano-additives at concentrations ranging from 0.25 to 3 wt%.The average nanoparticle size varied from 10 to 151 *** temperature of drilling fluids varied from 25℃ to 80℃.it is shown that the addition of nanoparticles to drilling fluids leads to a significant change in their rheological properties depending on the *** was found that with increasing temperature,the yield stress and consistency index of drilling fluids with nanoparticles increase,while the behavior index,on the contrary,*** behavior depends on the size of the *** the particle size increases,their influence on the temperature dependence of the drilling fluids’viscosity *** general,it is shown that the addition of nanoparticles makes the viscosity of drilling fluid more stable with regard to the *** is an essential fact for practical application.

关键词： Drilling fluid Nano-additive Viscosity Rheology Temperature

On n-Widths of a Sobolev Function Class in Orlicz Spaces

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Acta Mathematica Sinica,English Series 2015年第9期31卷 1475-1486页

作者： Xiao Li waNG ga Ridi WU College of Statistics and Mathematics Inner Mongolia University of Finance and Economics College of Mathematics Science Inner Mongolia Normal University

This paper considers the problem of n-widths of a Sobolev function class Ωr∞ determined by Pr（D） = DσПlj=1 （D2 - tj2i） in Orlicz spaces. The relationship between the extreme value problem and width theory is revealed by using the methods of functional analysis. Particularly, as σ = 0 or σ = 1, the exact values of Kolmogorov＇s widths, Gelfand＇s widths, and linear widths are obtained respectively, and the related extremal subspaces and optimal linear operators are given.

关键词： n-width extremal subspace optimal linear operator Orlicz space

B(E2) value of even-even ^(108-112)Pd isotopes by interacting boson model-1

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Chinese Physics C 2014年第2期38卷 24-28页

作者： i.Hossain H.y.Abdullah i.M.Ahmad M.A.Saeed Department of Physics Rabigh College of Science and Arts King Abdulaziz University Department of Physics College of Education Scientific Department Salahaddin University Department of Physics College of Education Mosul University Department of Physics Faculty of Science Universiti Teknologi Malaysia

This work studies the systematic reduced transition probabilities B（E2）↓, intrinsic quadrupole moments and deformation parameters of Pd isotopes with even neutrons from N =62 to 66. The downward reduced transition probabilities B（E2）↓from gamma transition 8^＋to 6^＋, 6^＋ to 4^＋, 4^＋ to 2^＋ and 2^＋ to 0＋states of even-even108 112Pd isotopes were calculated by the interacting Boson Model（iBM-1） and compared with the available previous experimental results. The ratio of the excitation energies of the first 4＋and the first 2＋excited states, R4/2, is also studied for the classification of symmetry of these nuclei. Furthermore we have studied systematically the transition rate R = B（E2： L＋ →（L 2）＋）/B（E2 ： 2＋ →0＋） of some of the low-lying quadrupole collective states in comparison with the available experimental data. The associated quadrupole moments and deformation parameters have been calculated. The results of this calculation are in good agreement with the corresponding available experimental data. The108 112Pd isotopes show the O（6） symmetry.

关键词： B(E2) ground-states Pd isotopes.quadrupole moments deformation parameter

Hydrogen transport in metals: integration of permeation, thermal desorption and degassing

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Journal of Materials Science & Technology 2017年第12期33卷 1433-1447页

作者： E.i.galindo-Nava B.i.y.Basha P.E.J.Rivera-Díaz-del-Castillo Department of Materials Science and Metallurgy University of Cambridge Department of Engineering Lancaster University

A modelling suite for hydrogen transport during electrochemical permeation, degassing and thermal desorption spectroscopy is presented. The approach is based on Fick＇s diffusion laws, where the initial concentration and diffusion coefficients depend on microstructure and charging conditions. The evolution equations are shown to reduce to classical models for hydrogen diffusion and thermal desorption spectroscopy. The number density of trapping sites is found to be proportional to the mean spacing of each microstructural feature, including dislocations, grain boundaries and various precipitates. The model is validated with several steel grades and polycrystalline nickel for a wide range of processing conditions and microstructures. A systematic study of the factors affecting hydrogen mobility in martensitic steels showed that dislocations control the effective diffusion coefficient of hydrogen. However,they also release hydrogen into the lattice more rapidly than other kind of traps. it is suggested that these effects contribute to the increased susceptibility to hydrogen embrittlement in martensitic and other high-strength steels. These results show that the methodology can be employed as a tool for alloy and process design, and that dislocation kinematics play a crucial role in such design.

关键词： Hydrogen Diffusion Modelling Trapping Permeation Desorption

Hybrid therapy for Helicobacter pylori infection:A systemic review and meta-analysis

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World Journal of gastroenterology 2015年第45期21卷 12954-12962页

作者： Ping-i Hsu Pei-Chin Lin David y Graham Division of gastroenterology Department of Internal Medicine Kaohsiung Veterans General Hospital and National Yang-Ming University Department of Pharmacy Kaohsiung Veterans General Hospital College of Pharmacy Kaohsiung Medical University Department of Medicine/gastroenterology Michael E. De Bakey Veterans Affairs Medical Center and Baylor College of Medicine Houston

AiM: To compare the effectiveness of hybrid therapy with other recommended regimens using ***: Bibliographical searches for randomized trials comparing hybrid and other therapies were performed in Pubmed, the Cochrane Library and relevant congresses up to February 2015 using the following keywords(all fields and/or me SH):("Helicobacter pylori " or "H. pylori") and("hybrid therapy" or "sequential-concomitant therapy"). metaanalyses were performed with Cochrane Review manager 5.1. The random effect model proposed by Der Simonian and Laird and the mantel-Haenszel method were used to estimate the pooled relative risk and 95%Ci of the efficacy outcomes between hybrid therapy and other eradication therapies. RESULTS: Eight studies(2516 subjects) met entry criteria. The antimicrobial resistance in the study groups ranged from 6.9% to 23.5%. The mean cure rates of hybrid therapy by intention-to-treat(iTT) and perprotocol analyses were 88.5%(n = 1207; range: 80.0% to 97.4%) and 93.3%(n = 1109; range: 85.7% to99.1%), respectively. meta-analysis showed there was no significant difference in iTT eradication rate between hybrid and sequential therapy(relative risk: 1.01; 95%Ci: 0.92-1.11). Subgroup analysis revealed hybrid therapy was more effective than sequential therapy in the non-italian populations(95%Ci: 1.01-1.18) and was only less effective in one, italian population(95%Ci: 0.83-0.98). There was no significant difference in eradication rate between hybrid therapy and concomitant therapy(95%Ci: 0.93-1.02). No head-tohead comparisons of hybrid therapy and standard triple therapy or bismuth quadruple therapy were found. However, a multicenter, randomized trial showed that reverse hybrid therapy was superior to standard triple therapy(95.5% vs 88.6% iTT; P = 0.011).CONCLUSiON: Hybrid therapy appears to be an effective, safe, and well-tolerated treatment for H. pylori infection in the era of increasing antibiotic resistance.

关键词： Helicobacter pylori Concomitant therapy Hybrid the

Transfusion-transmitted virus in association with hepatitis A-E viral infections in various forms of liver diseases in india

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World Journal of gastroenterology 2006年第15期12卷 2432-2436页

作者： M irshad y Sharma i Dhar J Singh yK Joshi Clinical Biochemistry Division Department of Laboratory Medicine All India Institute of Medical SciencesAnsari NagarNew Delhi 110029India Department of gastroenterology & Human Nutrition Unit All india institute of Medical Sciences Ansari NagarNew Delhi-110029India

AiM： To describe the prevalence of transfusiontransmitted virus （TTV） infection in association with hepatitis A-E viral infections in different forms of liver diseases in North india. METHODS： Sera from a total number of 137 patients, including 37 patients with acute viral hepatitis （AVH）, 37 patients with chronic viral hepatitis （CVH）, 31 patients with cirrhosis of liver and 32 patients with fulminant hepatic failure （FHF）, were analyzed both for TTV-DNA and hepatitis A-E viral markers. Presence of hepatitis B virus （HBV）, hepatitis C virus （HCV） and hepatitis E virus （HEV） infections was detected in different proportions in different groups. Moreover, rrV-DNA was simultaneously tested in 100 healthy blood donors also. RESULTS： None of the patients had hepatitis A virus （HAV） and hepatitis D virus （HDV） infections. Overall prevalence of TTV-DNA was detected in 27.1% cases with AVH, 18.9% cases with CVH, 48.4% cases with cirrhosis and 9.4% cases with FHF. TTV-DNA simultaneously tested in 100 healthy blood donors showed 27% positivity. On establishing a relation between TTV infection with other hepatitis viral infections, TTV demonstrated co-infection with HBV, HCV and HEV in these disease groups. Correlation of TTV with ALT level in sera did not demonstrate high ALT level in TTV-infected patients, suggesting that Ti-V does not cause severe liver damage. CONCLUSiON： TTV infection is prevalent both in patients and healthy individuals in india. However, it does not have any significant correlation with other hepatitis viral infections, nor does it produce an evidence of severe liver damage in patients with liver diseases.

关键词： Transfusion-transmitted virus HCV hepatitis AVH

Production of porous silica by the combustion of rice husk ash for tundish lining

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Journal of University of Science and Technology Beijing 2008年第3期15卷 307-313页

作者： y.M.Z.Ahmed E.M.Ewais Z.i.Zaki Central Metallurgical Research and Development institute(CMRDi)

in order to study the production of porous silica compacts by the combustion of rice husk ash （RHA） for tundish lining, the experimental design technique was used to evaluate the effect of firing temperature, soaking time and compaction pressure on controlling both the porosity degree and compressive strength of rice husk ash compacts. The results revealed that while the porosity degree of the compacts decreased with the increase in the entire studied parameters, the compressive strength exhibited another trend especially at a lower soaking time. At a lower soaking time, the increase in firing temperature led to a slight decrease in compressive strength and then increasing thereafter. The porous silica compacts having 30% porosity and 〉 2.5 MPa compressive strength suitable for tundish lining could be obtained from the combustion of rice husk ash compacts.

关键词： porous silica rice husk ash tundish lining compressive strength porosity