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New Naturally Occurring Product Extract as Corrosion Inhibitor for 316 Stainless Steel in 5% HCl

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Journal of Materials Science & technology 2004年第4期20卷 463-466页

作者： t.Y.Soror Chemistry Department Faculty of Science Cairo University Cairo Egypt

Medipolymorphol, a new sterol isolated from the whole plant of Medicago polymorpha Roxb was used as corrosion inhibitor for 316 stainless steel in 5% HCI at room temperature. Electrochemical techniques have been found to be reliable in evaluating corrosion characteristics of the system. Several techniques have been used including tafel, linear polarization, potentiodynamic polarization, and open circuit potential (OCP) studies. the additives simultaneously deaccelerated the anodic process, intensified the cathodic process and provided a stable passive state, giving good inhibition efficiencies to stainless steel electrodes. In addition, adsorption isotherm have been fitted for the inhibitor under investigation.

关键词： Medipolymorpho] Plant extract Stainless steel HCl Corrosion inhibitor

Ion Heating from Nonlinear Landau Damping of High Mode Number toroidal Alfvén Eigenmodes

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Plasma Science and technology 2015年第7期17卷 534-538页

作者： t.S.HAHM Department of Nuclear Engineering Seoul National University

Bulk ion heating rate from nonlinear Landau damping of high mode number toroidal Alfven Eigenmodes （tAEs） is calculated in the frame work of weak turbulence theory. the heating rate is lower than the nonlinear spect... 详细信息

关键词： Alfven wave nonlinear Landau damping toroidal Alfven eigenmode

Free vibration analysis of laminated FG-CNt reinforced composite beams using finite element method

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Frontiers of Structural and Civil Engineering 2019年第2期13卷 324-336页

作者： t.VO-DUY V.HO-HUU t.NGUYEN-tHOI Division of Computational Mathematics and Engineering Institute for Computational ScienceTon Due Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Due Thang UniversityHo Chi Minh CityVietnam

In the present study, the free vibration of laminated functionally graded carbon nanotube reinforced composite beams is analyzed. the laminated beam is made of perfectly bonded carbon nanotubes reinforced composite (CNtRC) layers. In each layer, single-walled carbon nanotubes are assumed to be unifonnly distributed (UD) or functionally graded (FG) distributed along the thickness direction. Effective material properties of the two-phase composites, a mixture of carbon nanotubes (CNts) and an isotropic polymer, are calculated using the extended nile of mixture. the first-order shear deformation theory is used to formulate a governing equation for predicting free vibration of laminated functionally graded carbon nanotubes reinforced composite (FG?CNtRC) beams. the governing equation is solved by the finite element method with various boundary conditions. Several numerical tests are perfbnned to investigate the influence of the CNts volume fractions, CNts distributions, CNts orientation angles, boundary conditions, length-to-thickness ratios and the numbers of layers on the frequencies of the laminated FG-CNtRC beams. Moreover, a laminated composite beam combined by various distribution types of CNts is also studied.

关键词： free vibration analysis laminated FG-CNtRC beam finite element method first-order shear deformation theory composite material

Phase Composition of Sputtered Film from a Mixture target of Hydroxyapatite and Strontium-apatite

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Journal of Materials Science & technology 2013年第1期29卷 1-6页

作者： K.Ozeki t.Hoshino H.Aoki t.Masuzawa Department of Mechanical Engineering Ibaraki University International Apatite Co. Ltd.

to obtain an Sr-substituted hydroxyapatite thin film, sputter-coating was performed on a cellulose filter acting as a substrate from the mixture target of hydroxyapatite （HA） and strontium-apatite （SrAp） at an Ar pressure of 0.5-5.0 Pa. the ratio of the SrAp in the mixture target was varied from 25% to 100%. After coating, the films were heated at 700 ℃ to remove the cellulose filter substrate, and the crystalline phases were identified by X-ray diffraction （XRD）. the sputter-coated film was identified as the Sr-substituted /3-tri-calcium phosphate （tCP） and the Sr-substituted/3-calcium pyrophosphate （CPP） as well as the Sr-substituted HA. the weight ratio of the Sr-substituted HA decreased with increasing Ar pressure or with an increasing ratio of SrAp to HA in the target. the average Sr/（Ca ＋ Sr） molar ratio in the film was 1.9%-3.5% slightly lower than the initial SrAp ratio of the target, and the ratio was not influenced by the Ar pressure. In the （Sr ＋ Ca）/P ratio, the ratio decreased while increasing the SrAp ratio in the target.

关键词： Sputtering Hydroxyapatite Strontium Strontium-apatite Crystal phase

InP/GaInP nanowire tunnel diodes

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Nano Research 2018年第5期11卷 2523-2531页

作者： Xulu Zeng Gaute Otnes Magnus Heurlin Renato t Mourao Magnus t Borgstrom Solid State Physics NanoLund Department of Physics Lund University P.O. Box 118 Lund 5E-22100 Sweden Instituto de Fisica Universidade Federal do Rio de Janeiro Caixa Postal 68528 Rio de Janeiro 21941-972 Brazil

Semiconductor nanowire （NW） solar cells with a single p-n junction have exhibited efficiency comparable to that of their planar counterparts with a substantial reduction in material consumption. tandem geometry is a path toward the fabrication of devices with even higher efficiencies, for which a key step is the fabrication of tunnel （Esaki） diodes within NWs with the correct diameter, pitch, and material combination for maximized efficiency. InP/GaInP and GaInP/InP NW tunnel diodes with band gap combinations corresponding to high-efficiency solar energy harvesting were fabricated and their electrical characteristics and material properties were compared. Four different configurations, with respect to material composition and doping, were investigated. the NW arrays were grown with metal-organic vapor-phase epitaxy from Au particles by use of nano-imprint lithography, metal evaporation and lift-off. Electrical measurements showed that the NWs behave as tunnel diodes in both InP （bottom）/GaInP （top） and GaInP （bottom）/InP （top） configurations, exhibiting a maximum peak current density of 25 A/cm^2, and maximum peak to valley current ratio of 2.5 at room temperature. the realization of NW tunnel diodes in both InP/GaInP and GaInP/InP configurations represent an opportunity for the use of NW tandem solar cells, whose efficiency is independent of the growth order of the different materials, increasing the flexibility regarding dopant incorporation polarity.

关键词： nanowire tunnel diode InP GaInP tandem junction solar cell

Performance Analysis of Mini Centrifugal Pump with Splitter Blades

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Journal of thermal Science 2013年第6期22卷 573-579页

作者： t. Shigemitsu J. Fukutomi t. Wada H. Shinohara Institute of technology and Science The University of Tokushima 2-1 Minamijosanjima-cho Tokushima 770-8506Japan Graduate School of Advanced technology and Science The University of Tokushima 2-1 Minamijosanjima-choTokushima 770-8506 Japan

Design method for a mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. then, a semi-open impeller for the mini centrifugal pump with 55mm impeller diameter is adopted in this research to take simplicity and maintenance into consideration. Splitter blades are adopted in this research to improve the performance and internal flow condition of mini centrifugal pump having large blade outlet angle. the performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on the performance and internal flow condition of the mini centrifugal pump. A three dimensional steady numerical flow analysis is conducted to analyze rotor, volute efficiency and loss caused by a vortex. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. Flow condition at outlet of the rotor becomes uniform and back flow regions are suppressed in the case with the splitter ***, the volute efficiency increases and the vortex loss decreases. In the present paper, the performance of the mini centrifugal pump is shown and the flow condition is clarified with the results of the experiment and the numerical flow analysis. Furthermore, the performance analyses of the mini centrifugal pumps with and without the splitter blades are conducted.

关键词： Centrifugal pump Performance Internal flow Splitter blade

Unsteady Internal Flow Conditions of Mini-Centrifugal Pump with Splitter Blades

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Journal of thermal Science 2013年第1期22卷 86-91页

作者： t. Shigemitsu J. Fukutomi K. Kaji t. Wada Institute of technology and Science The University of Tokushima Graduate School of Advanced technology and Science The University of Tokushima

Mini centrifugal pumps having a diameter smaller than lOOmm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. therefore, mini cen- trifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this re- search to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. the original impeller without the splitter blades and the impeller with the splitter blades were prepared for experiment. the performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional unsteady numerical flow analysis was conducted to investigate the change of the internal flow according to the rotor rotation. It is clarified from the experimental results that the performance of the mini cen- trifugal pump is improved by the splitter blades. the blade-to-blade low velocity region was suppressed in the case with the splitter blades. In addition to that, the unsteady flows near the volute casing tongue were suppressed due to the splitter blades. In the present paper, the performance of the mini centrifugal pump is shown and the un- steady flow condition is clarified with the results of the numerical flow analysis. Furthermore, the effects of the splitter blades on the performance and the unsteady internal flow condition are investigated.

关键词： Mini-centrifugal pump Unsteady flow condition Performance Splitter blades

Electrodeposition of aluminium and aluminium-copper alloys from a room temperature ionic liquid electrolyte containing aluminium chloride and triethylamine hydrochloride

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International Journal of Minerals,Metallurgy and Materials 2013年第9期20卷 909-916页

作者： P.V. Suneesh t.G. Satheesh Babu t. Ramachandran Department of Sciences Amrita School of Engineering Amrita Vishwa Vidyapeetham Amritanagar P. O.Coimbatore - 641112India

the electrodeposition of A1 and A1-Cu binary alloys on to gold substrates from a room temperature ionic liquid electrolyte containing A1C13-EtaNHC1 was studied. the electrochemical behavior of the electrolyte and the mechanism of deposition were investigated through cyclic voltammetry （CV）, and the properties of deposits obtained were assessed by scanning electron microscopy with energy dispersive X-ray spectroscopy （SEM-EDS） and X-ray diffraction （XRD）. A1 of 70μm in thickness and an A1-Cu alloy of 30μm in thickness with 8at% copper were deposited from the electrolyte. SEM images of the deposits indicate that the A1 deposit was smooth and uniform, whereas the Al-Cu deposit was nodular. the average crystalline size, as determined by XRD patterns, was found to be （30±5） and （29±5） nm, respectively, for A1 and A1-Cu alloys. Potentiodynamic polarization （tafel plots） and electrochemical impedance spectroscopic （EIS） measurements showed that Al-Cu alloys are more corrosion resistant than Al.

关键词： electrodeposition aluminium copper alloys ionic liquids triethylamine hydrochloride copper acetylacetonate

Effect of Doping and High-temperature Annealing on the Structural and Electrical Properties of Zn_(1-X)Ni_XO(0≤X≤0.15) Powders

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Journal of Materials Science & technology 2011年第10期27卷 944-950页

作者： Hakan olak Orhan trkoglu Department of Chemistry Faculty of ScienceUniversity of Erciyes

this paper reported the synthesis, crystal structure and electrical conductivity properties of Ni-doped ZnO powders （i.e. Zn1-xNixO binary system, X=0, 0.0025, 0.005, 0.0075 and in the range 0.01≤X〈0.15）. I- phase samples, which were indexed as single phase with a hexagonal （wurtzite） structure in the Zn1-xNixO binary system, were determined by X-ray diffraction （XRD）. the widest range of the I-phase was determined as 0≤X≤0.03 at 1200℃; above this range the mixed phase was observed. the impurity phase was determined as NiO when compared with standard XRD data, using the PDF program. We focused on single f-phase ZnO samples which were synthesized at 1200℃ because of the widest range of solubility limit at this temperature. It was observed that the lattice parameters a and c of the I-phase decreased with Ni doping concentration. the morphology of the I-phase samples was analyzed with a scanning electron microscope. the electrical conductivity of the pure ZnO and single I-phase samples were studied by using the four-probe dc method at temperatures between 100 and 950℃ in air atmosphere. the electrical conductivity values of pure ZnO and 3 mol% Ni-doped ZnO samples at 100℃C were 2×10^-6 and 4.8×10^-6 Ω-***^-1, and at 950℃ they were 1.8 and 3.6 Ω-1cm-1, respectively. In other words, electrical conductivity increased with Ni doping concentration.

关键词： Ⅱ-Ⅵ semiconductors Zinc oxide and doped zinc oxide Four point probe method