bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of the SCR Catalyst Ce-V/TiO2
Authors: Wang Fen , Ren Xiu Feng , Zhu Jian Feng , Yang Hai Bo
Published: March 2009

The Ce-V/TiO2 catalysts with the selective catalytic reduction (SCR) were prepared by method of Sol-gel and insuccation. The phase compositions, microstructures and specific surface area of the catalysts were analyzed by XRD, SEM and BET, respectively. The effect of CeO2 and V2O5 loading and reaction temperature on the catalytic performances of the as-prepared catalysts was investigated by using the selective reduction of NOx with NH3. The results showed all the as-prepared Ce-V/TiO2 catalysts were made up of nanometer grains. Compared to conventional TiO2 catalysts, the as-prepared Ce-V/TiO2 catalysts possessed better catalytic performance, higher adsorbability and larger area of contact with reactant, which is due to large quantity surface micropores. The NOx conversion of SCR over 5wt%Ce-10wt%V/TiO2 catalysts reached 96.2% at the reaction temperature of 500 oC.
Preparation of Eco-Friendly Composite Ceramic from Iron Ore Tailings
Authors: Liu Ming , Xu Li Hua , Zhang Xiao Meng , Hao Hong Shun , Di Yun Ping
Published: March 2009

In this paper, the research mainly focused on utilization of iron ore tailing of Panzhihua region. Based on the analysis of its components, Carbothermal Reduction Nitridation (CRN) method was selected to synthesize eco-friendly composite material. Different additives were tried to improve the property of the samples. The influence of different sintering temperature, holding time and contents of additives were taken into account, and orthogonal design was employed to obtain the optimal parameters. It indicated that only when the temperature was 1450°C and the holding time was 5 hours, the samples with the bulk density of 3.42g/cm3 was obtained. The phase and surface morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Experimental results showed that the phases of the product were Fe3Si and TiC0.3N0.7. The research provided a novel recycling process for ore tailings.
Photo-Catalytic Activity of Cu2O Films with Various Crystal Structures Prepared by DC Reactive Magnetron Sputtering
Authors: Zhu Hai Ling , Zhang Jun Ying , Lan Xiang , Li Chun Zhi , Wang Tian Min , Huang Bai Biao
Published: March 2009

The direct current (DC) reactive magnetron sputtering of a metal copper target in oxygen-argon mixed atmospheres to produce thin films of crystalline copper oxides was described. The sputtering pressure, sputtering power and oxygen flow rate were established in order to control the structures and properties of Cu2O films. The as-deposited Cu2O films with various crystal structures have high visible absorption and photo-catalytic activity under visible light irradiation. The photo-catalytic properties of Cu2O films are affected by not only the crystal structure but also the surface morphology.
Experimental Study on Macro-Kinetics of Flue Gas Desulfurization Using Pyrolusite Pulp by a Double Magnetic Stirred Reactor
Authors: Zhao Jing Dong , Su Shi Jun , Zhu Xiao Fan , Wang Hong Lei
Published: March 2009

It’s a gas-liquid-solid three-phase reaction system in the reactor for flue gas desulfurization using pyrolusite pulp. Based on the two-film mass transfer theory and shrine core model, the macro-kinetics of flue gas desulfurization using pyrolusite pulp in a double magnetic stirred reactor were investigated. The effects of diffusion in solid film, surface chemical reaction, diffusion in liquid phase and gas phase of the process, have been carried out to distinguish the control step of the process. It was observed that SO2 absorption efficiency increased with the decreasing of pyrolusite particle size and varied gently when the pyrolusite particle diameter decreased to 0.18mm. SO2 absorption efficiency increased not significantly along with the increase of temperature and the liquid phase stirring speed but increased significantly along with the increase of the gas phase stirring speed. Experiment results showed that under simulated industrial conditions, gas phase diffusion was the control step compared to other related factors, given that pyrolusite particle diameter was kept below 0.1mm.
O2 Reduction Reaction Activity of MN4 Spherical Polymeric Cobalt Porphyrin
Authors: Xie Jia , Xia Ding Guo , Yu Zhi Hui
Published: March 2009

A novel cathode catalyst for direct methanol fuel cell, MN4 polymeric cobalt tetrametho -xyphenyl porphyrin (PCoTMPP), was prepared by solvent thermal method. The PCoTMPP exhibited spherical particles with diameter of 0.8~1µm. The spherical PCoTMPP showed a good monodisperse. The oxygen reduction reaction activity of PCoTMPP was examined by CV, LSV and CA methods. The results showed that PCoTMPP has a better oxygen reduction reaction activity and stability in comparison with CoTMPP and leads to a four-electron reduction of dioxygen to water.
The Study of Boron-Doped Nanocrystalline Silicon Film with High Conductivity
Authors: Liu Hao , Zhang Wei Jia , Jia Shi Liang , Guo Wei , Wu Jin
Published: March 2009

Boron-doped nanocrystalline silicon film was prepared through plasma enhanced chemical vapor deposition (PECVD) on silicon substrate and glass substrate under the high deposition pressure (332.5-399Pa) and the high deposition temperature (320-360°C). The film was investigated by Raman, electron probe microanalyser, conductivity and mobility experimenting techniques. The conductivity of the boron-doped nanocrystalline silicon film was 2.97×102Ω-1cm-1. The results showed that the interface between the film and the silicon substrate might have quantum spot and small size effect, causing the increasing of conductivity.
Influences of Stabilizers on the Microstructure and Properties of Sol-Gel Tin Doped Indium Oxide Thin Films
Authors: Xu Xue Qing , Zhang Yu , Xu G.
Published: March 2009

The tin doped indium oxide (ITO) thin films were prepared by sol-gel dip-coating process from InCl2.4H2O and SnCl4 in alcoholic solutions. The influences of organic ligands, including acetylacetone (AcAc) and diethanolamine (DEA), on the stability and the composition of the sols, and on the microstructure and properties of the thin films have been investigated. It is indicated that a suitable amount of DEA or AcAc helped to keep the stability of the ITO sols, and helpful for the formation of the homogeneous thin films. The TG-DSC and X-ray diffraction analysis revealed that the organic ligands also had effect on the crystallization temperature and crystal structures of the thin films. The thin films with DEA as coordination ligands had a good crystal quality when heated at 450°C. As a result, it exhibited a better electrical property than that with AcAc as stabilizers.
Processing 20 Ply Clad Plate by Accumulative Clad Rolling from Stainless Steel/Aluminum/Aluminum Alloy…/Stainless Steel Sheets
Authors: Pang Yu Hua , Yuan Jia Wei , Sun Qi , Hu Yang Lei
Published: March 2009

According to the principle of accumulative roll bonding(ARB),the 20 ply clad sheet from austenitic stainless steel (STS304)/pure aluminum(Al1060)/aluminum alloy(Al3003) …/ austenitic stainless steel (STS304)sheets with excellent heat, anti-corrosion and mechanical properties of stainless steel and the high thermal and electrical conductivities of aluminum was fabricated by accumulative clad rolling (ACR). Well-bonded clad plate was successfully obtained in the procedure: Al1060 sheets with a thickness of 0.5mm and Al3003 sheets 0.5mm thick and STS304 sheets 0.5mm thick were employed. Basic clad sheet from different ply Al1060/Al3003 sheets was obtained with an initial rolling reduction of 44% at 450°C followed by annealing at 300°C, then ACR was with reduction of 50% at 550°C from STS304 on each side. The stretch property, bonding property, microscopic structure and interface composition were measured and analyzed. It was indicated that the best clad sheet had bonding strength of 129MPa and stretch strength of 225MPa. was of 129Mpa bonding strength and 225Mpa stretch strength. At the end,STS304 sheet with thickness of 3mm which being used in superior quality kitchenware and finishing material and so on was taken the place of the clad sheet from STS304 sheets of 1mm and Al1060 of 1mm and Al3003 of 1mm. Therefore, it decreased by 44% in weight and economizes rare metal elements Cr and Ni of 66% in weight.
Preparation of Nanosize Iron Pyrite FeS2 and its Properties
Authors: Zou Jian , Gao Jia Cheng
Published: March 2009

The nano-particle pyrite in nano-particle form was synthesized by the deposition hydrothermal reaction using FeCl3•6H2O, Na2S•9H2O and S as the starting materials. The property of particles was investigated by X-ray diffraction, transmission electron microscope, UV-Vis spectrophotometer. The results indicated that the pure iron pyrite could be achieved in the alkaline condition. Increasing the proportion of S avails to removing marcasite and ferric oxide . Wwhen the amount of FeCl3, Na2S and S is in the ratio of 1:3:1.5, the product is pure pyrite FeS2 powder with a polyhedron shape is obtained and the average particle size isof about 20~40nm, and this result can be easily repeated. Optical analysis indicates that the optic energy band gap is about 1.62 eV. Its open circuit voltage is 456mV, and the corresponding short circuit current is 19 μA.
Optimizing on the Negative Electrode of Ni/MH Power Battery by Orthogonal Design
Authors: Zhong Xiao Liang , Zhu Lei , Jian Xu Yu , Yu Hai Jun , Wang Zhong
Published: March 2009

In this paper, the influences of different binders (Hydroxypropyl Methyl Cellulose (HPMC), Carboxymethyl Cellulose Sodium (CMC), Polytetrafluoroethylene (PTFE) and Styrene- butadiene Rubber (SBR)) on high-rate discharge performances at low temperature for the negative electrode of Ni/MH battery have been studied by orthogonal experimental design. Electrochemical measurements have been conducted to investigate the capacity, charge-discharge performance, cyclic voltammetry and electrochemical impedance characteristics. The surface morphology and chemical compositions have been investigated by SEM and EDS. Based on the range analysis, the primary and secondary influence factors as well as the optimization results were obtained. From the CV characteristic curves, the oxidization peaks and reduction peaks are not clearly shown, which indicates that the redox reaction does not occur clearly after binders added. The EIS experiments show that the deterioration of the voltage characteristic of the battery is due to drying out of the separator that increases the ohmic resistance (Rs ), and the decay of the discharge capacity is due to the passivity surface that increases the charge-transfer resistance (Rt) of the battery.
Research of a Novel MEMS Vector Hydrophone Based on a New Package Process
Authors: Zhang Kai Rui , Li Qiu Zhu , Liu Guo Wen , Shi Xiao Jun
Published: March 2009

A new method for the MEMS die package process was reported. Using the method of bionic package, a novel MEMS vector hydrophone was fabricated from a typical mass-beam accelerometer structure. According to the auditory principle of fish’s lateral line and its nature’s fundamental acoustic sensors-stereocilia, a rigidity cylinder was fixed on the center of the mass as a stereocilia, and the sensitivity structure of the hydrophone was obtained. By means of a specific package process, the sensor was fabricated properly for the underwater sound detection application. From the test results of the sensor, we can see that, this vector hydrophone has a receiving sensitivity of -165dB (0dB=1V/µPa, the amplification factor of the preamplifier is 100.) and a good directional pattern in form of “8”-shape. The hydrophone can work well under the maximum pressure of 2MPa.
Study on the Microstructure and Deformation Behavior of Ultrafine-Crystalline Cu-Y Ribbons
Authors: Du Zhi Wei , Sun Z.M. , Shao B.L. , Liu A.S.
Published: March 2009

Cu99.8Y0.2, Cu99.2Y0.8 and Cu98Y2 alloy ribbons were prepared by single roller melt spinning. The microstructure was studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), high voltage electron microscope (HVEM) and high resolution electron microscopy (HREM). The results showed that α-Cu was the dominative phase in the rapid solidification ribbons of three alloys. A secondary phase Cu4Y was detected in the Cu98Y2 ribbon by XRD. The grain size was in a range of 50-200 nm in the Cu99.2Y0.8 and Cu98Y2 ribbons. Many nano-scale twins and some dislocations existed inside the larger grains. However, the grains in Cu99.8Y0.2 ribbon were in the size of microns and the sub-grains with small misorentations were in 100-200 nm. To understand the deformation mechanism, in situ tensile test were carried out at a High Voltage Electron Microscope (HVEM). The results showed that the deformation is predominated by the dislocation slip in larger grains. To accommodate the deformation, elastic deformation occured in the small grains in the initial stage of the deformation. Meanwhile, some small grains maybe deform by grain rotations. With strain increasing, some fractures generated and propagated along the grain boundaries or across the grains.
Photoluminescence Properties Influenced by Calcining Condition and Doping Concentration of Nano-Sized ZnGa2O4: Cr3+
Authors: Zhang Wei Wei , Zhang Jun Ying , Wan Hui , Chen Zi Yu , Wang Tian Min
Published: March 2009

Chromium-activated ZnGa2O4 nano-sized phosphor powder was prepared by the Sol-Gel technique using citric acid as chelator, and the microstructure and luminescent property were studied. The host ZnGa2O4 belongs to the spinel structure and the ZnGa2O4:Cr3+ phosphor powder exhibited bright red emission band. The excitation bands with peak of maximum height at about 250 nm, 410 nm and 560 nm were related to the charge transfer (CT) of Ga-O, 4A2-4T1 and 4A2-4T2 transitions of Cr3+, respectively. Different quenching concentrations of the CT state and intrinsic excitation were discovered originating from different energy transfer schemes. Meanwhile, with the increasing of the calcining temperature the PLE spectrum exhibited an obvious blue-shift which is attributed to the enhancement of the crystal field.
Study of a New Chromium Carbide Reinforced Ni3Al Matrix Composite Hardfacing Material on IC6SX
Authors: Sun Lu , Li Shu Suo , Jiang Li Wu , Han Ya Fang
Published: March 2009

The microstructure and property of a new high temperature surface wear-resistant chromium carbide/Ni3Al composite deposited onto IC6SX alloy by manual argon tungsten-arc welding.have been investigated The microstructures of the WL(welding layer), HAZ(heat affected zone), BM(base metal) were observed by SEM and Optical microscope and analyzed by EDS and EMPA. Since the large amount of Mo which diffused from the substrate IC6SX strongly effected the formation of hard phases in the welding layer, the microstructures of WL in this study turned out to be very different from former studies where the different materials were chosen as base metals. Due to the high welding temperature and the rapid cooling process, the microstructures in HAZ were much smaller than that in BM. And the microhardness tests results illustrated that the two materials were well metallurgically bonded.
Strength Properties of Thin Alumina Coatings on 4043 Aluminum Alloy
Authors: Gong Man Feng , Qiao Sheng Ru , Zhang Cheng Yu , Ji Hao
Published: March 2009

Alumina (Al2O3) coatings in the thickness of 10μm and 15μm were prepared on the 4043 Al-Si alloy substrates by electroplating technology. Multiple mechanical properties of alumina coatings were evaluated by various techniques: the long distance microscope, Charge Coupled Device microphotographics, acoustic emission and strain foils. For the electroplating alumina coatings, the in-plane tensile strength is 68.1 MPa, the cohesive strength is 96.2 MPa and the adhesive strength is over 22.7 MPa. Three different directional microcracks, which are relative to the tensile directional and corresponding to two fail modes in the alumina (coatings)/4043 Al-alloy (substrate) system, were found.
Resistance Spot Welding Process of Galvanized Steel Sheet Based on Regression Modeling
Authors: Luo Yi , Ye Hong , Xiong Cheng Zhi , Liu Lin , Lv Xu Wei
Published: March 2009

The resistance spot welding process of galvanized steel sheet used in the body manufacturing of family car was studied, and the indexes of nugget geometry and tensile-shear strength of spot welds were tested. Four process parameters, namely welding current, electrode force, welding current duration and preheat current, and interactions among them were regarded as factors impacting indexes. Method using in mathematical models developing was nonlinear multiple orthogonal regression assembling design, which was optimized by the technology of variance analysis. The experimental results showed that more accurate prediction on nugget size and mechanical properties of spot welds can be obtained by the models optimized. With these prediction results, the optimization of welding process also was realized by the analysis to effect of the parameters and interactions on the welding quality.
Study of the Effect of Microstructure on the Anisotropy of AZ31 Magnesium Alloy Thin Sheet
Authors: Wang Qun Jiao , Zhang Yi Bin , Sun Ya Fei , Chen Jin Geng , Cui Jian Zhong
Published: March 2009

Stronger (0001) basal plane textures mainly include two types: and in AZ31 magnesium alloy thin sheet were formed after hot-rolling. The texture types of hot-rolled AZ31 magnesium alloy thin sheet after annealing at 523K and 673K respectively were as same as that of hot-rolled thin sheet without annealing, but texture intensities became weaker, especially after annealing at 673K. The strong texture of hot-rolled thin sheet caused anisotropy of mechanical properties (tensile strength b, yield strength s and elongation ) significantly , and the anisotropy reduced with the decrease of texture intensity after annealing. Besides texture, the grain shape also effects anisotropy of mechanical properties. The anisotropy becames more significantly with the increase of relative difference of grain diameter between transverse and longitudinal directions.
Effect of the Thickness of Dies for the Solidification Balance of Permanent Mould Casting AZ91D Magnesium Alloy
Authors: Zhao Jian Hua , Long Si Yuan , Xu Hui , Yan Li
Published: March 2009

The hot spot forming tendency during solidification of AZ91D magnesium alloy in permanent mould casting with the dies of different wall thickness via numerical simulation with Anycasting software was studied in the present paper. The experimental results showed that in a single cycle casting the increase in the thickness enhanced the cooling ability of the mould and promoted balanced solidification in a certain degree, while in multi-cycle casting, the thickened die-wall gradually lose its localized chilling effect. In contrast, the die with a decreased wall thickness in a certain range was easier to achieve the desired solidification balance.
Research on the Microstructures and Mechanical Properties of Annealed Cold Upsetting AZ31 Magnesium Alloy
Authors: Liu Tian Mo , Hu Wei Hui , Liu Qing
Published: March 2009

The microstructures and mechanical properties of cold upsetting magnesium alloys were investigated upon anneal under different conditions. The results show that a large amount of twins were observed in the original grains of cold upsetting AZ31 magnesium alloys. The twins disappeared gradually and recrystal grains formed after anneal. The volume fraction of the recrystal grains increases as the strain of samples rises. Recrystal grain size grows large with the elevated annealing temperature. Recrystal grain size reduces at first and then grows as the annealing time is prolonged. In addition, compared with as-cast magnesium alloys, the yield strength of cold upsetting samples increase apparently due to grain refinement after anneals.
Upper-Bound Analysis for Change-Channel Angular Extrusion
Authors: Liu Tian Mo , Liu Yu , Lu Li Wei , Pan Fu Sheng
Published: March 2009

Deformation of the material during 90° change-channel angular extrusion (CCAE) process is analyzed using upper-bound theorem. The mathematical model was established which includes the effect of friction between the sample and inner surface of the die, radius of inner and outer corner of the die, and the dead metal zone on the deformation patterns during change-channel angular extrusion deformation process. The model of parameters is explored in relation to the deformation of the material during the change-channel angular extrusion process. Results showed that the extrusion force increased with the increase of extrusion ratio (a2/b2), friction factor m, out corner and the reduce of inner corner. Further directions for progress in upper-bound analysis in change-channel angular extrusion deformation process are outlined.
Modelling Flue Gas Desulfurization Using Pyrolusite Pulp in a Jet Bubbling Reactor
Authors: Zhao Jing Dong , Su Shi Jun , Ai Nan Shan , Zhu Xiao Fan
Published: March 2009

A mathematical model for flue gas desulfurization using pyrolusite pulp in jet bubbling reactor (JBR) was described. Firstly, based on the concept of two stages mass balance with chemical reaction, two models were set up, for jet bubbling zone and rising bubble zone, respectively, according to the construction of JBR. The models consist of two coupling differential equations and were solved simultaneously by integral and separation of the variables. Then the SO2 absorption efficiency expression was developed, considering the great discrepancy existing between the gas-side mass transfer coefficients of the jet bubbling zone and gas bubble rising zone. The final expression associates SO2 absorption efficiency with process conditions and JBR structure parameters, which can give some instruction and guidance for the study of reactor operation process. Predicted results from the theoretical model, including effect of pH value of the pulp, flue gas temperature and inlet SO2 concentration of flue gas on SO2 absorption efficiency, were found to be in good agreement with experimental data obtained in a jet bubbling reactor. The model provides a basis for the process scale up and operating guide.
Morphology of α-Mg3Sb2 Precipitates in Mg-Sb Binary Alloys
Authors: Liu Hong Bin , Qi Guo Hong , Ma Yu Tao , Zhang Xing Guo
Published: March 2009

When Mg-10(wt.%)Sb alloy was melted, the alloy melt was into two tiers. The semisolid formed in the bottom of the melt became Mg-13Sb alloy and the upper of the melt became Mg-9Sb alloy. Both of Mg-9Sb and Mg-13Sb alloys consist of α-Mg phase and α-Mg3Sb2 precipitates which distributed homogenously in the matrices. In Mg-9Sb alloy, two types of precipitates are observed, the majority rod-shaped and the minority rectangle-shaped. In Mg-13Sb alloy, all of the precipitates were just block.
Mechanochemical Synthesis of Nanocrystalline Mg-Based Hydrogen Storage Composites in Hydrogen Alloying Mills
Authors: Zhang Jing , Yan Wei , Bai Chen Guang , Luo Xiao Dong , Pan Fu Sheng
Published: March 2009

Hydrogen storage in solid hydrides is the most attractive method of on-board hydrogen storage in fuel cell for cars. Mg metal exhibits a high-storage capacity by weight and has been considered a group of potentially attractive candidates for solid-state hydrogen storage. In this study, mechanochemical synthesis of nanocrystalline Mg-based hydrogen storage composites from various starting materials in specialized hydrogen ball mills has been achieved. The reactive synthesis process and the hydrogen desorption behaviors of the composite hydrides were investigated by X-ray diffraction (XRD), thermogravimetric and differential scanning calorimetry (TG-DSC). The results show that nano-sized MgH2 and Mg(AlH4)2 could be directly synthesized by pure Mg and pretreated Al powder, as well as Mg-Li-Al alloy powder. Alloying element Li could remarkably promote the synthesis of magnesium alanate, the product composite hydrides releasing 6.2wt% H2 through multi-step decompositions, of which the starting endothermic peaks are as low as 65°C.
Enhancement Corrosion Resistance of Two (Vinyl)Silsesquioxane Hybrid Films and their Validation by Gas-Molecule Diffusion Coefficients Using Molecular Dynamics Simulation
Authors: Wang Di , Chen Xiao Dong , Liu Yu , Hu Li Jiang
Published: March 2009

Based on silsesquioxanes (SSO) derived from hydrolytic condensation of (vinyl)trimethoxysilane (VMS) and tetraethoxysilane (TEOS), two hybrid films, f-VMS-SSO (f-VS) and f-VMS-TEOS-SSO (f-VTS) modified with 15 wt-% TEOS, were prepared. The anticorrosion properties (corrosion potential, Ecorr, and corrosion current density, Icorr) of the bare aluminum alloy (AA) and the two films on AA were tested by electrochemical measurements with typical potentiodynamic polarization curves. The Icorr values of three samples are significantly different in the order of f-VTS<f-VS<AA which implies that the TEOS addition in the f-VTS coating indeed enhances the electrochemical corrosion resistance. Correlations between the structures of two films and anticorrosion properties were discussed. Four different 3D-amorphous cubic unit cells, two cell(f-VS)s and two cell(f-VTS)s, as models were employed to investigate self-diffusion coefficients by molecular dynamics (MD) simulation for the NO2, SO2 and H2O molecules. All three self-diffusion coefficients of NO2, SO2 and H2O in cell(f-VTS) were less than the corresponding values in cell(f-VS), which validates the anticorrosion experiment results. The reasons why the addition of TEOS in the system of f-VTS leads to a lower gas self-diffusion coefficient compared to the f-VS system, were discussed.
Finishing Advanced Surface of Magnesium Alloy Tube Based on Abrasive Belt Grinding Techology
Authors: Huang Zhi , Huang Yun , Wu Yue Yu , Zhang Wei Wen
Published: March 2009

A new maching method of pretreatment magnesium alloy surface was design based on abrasive belt grinding technology, which offered a kind of technology for magnesium alloy tube surface machining. Experimental results indicated that abrasive grain granularity, belt speed and workpiece feed speed play an important role in grinding for magnesium alloy tube surface, which made magnesium alloy tube surface roughness from 0.22 um to 2.93 um with 400 grade to 80 grade on abrasive grain granularity of belt, raise the belt speed to reduce surface roughness, but raise workpiece feed speed to deteriorate roughness.
Inside Residual Stress Analysis of Carburizing-Nitriding Quenching Spur Gear by Neutron Diffraction Method
Authors: Mukai Ryuji , Ju Dong Ying , Suzuki Hiroshi
Published: March 2009

The purpose of this paper is coming thing by the neutron diffraction method in respect of inside residual stress of carburizing-nitriding quenching spur gear measure. Moreover, from Metallo-thermo-mechanical theory, simulation using the coupled analysis by finite element method is carried out, and the residual stress is predicted.
Shot Peening Using Wet Blasting Machine with a Wide Nozzle
Authors: Sakoda Seiki , Tosha Katsuji
Published: March 2009

This paper describes the influence of shot peening on of the peened surface and fatigue strength. Shot peening was performed by a wet blasting machine with a wide nozzle. At first, influences of particle size and geometry on characteristic values such as surface roughness, residual stress, FWHM, and Vickers hardness were examined, and then fatigue strength was studied on the peened materials. The material is a medium carbon steel (C:0.45%, 180HV) and the peening particles are alumina and glass beads. The following results are shown in this paper: (1) On the specimen a width of 83% of the wide nozzle is peened uniformly judging from chatterings of FWHM, compressive residual stresses and surface roughness. (2) Surface roughness, compression residual stress, FWHM and the maximum hardness increase with increasing particle size except for the case of 57μm particles; the maximum values are 0.52μm, 390MPa, 2.15deg, 205.6HV respectively. (3) Fatigue strength is improved using alumina and glass beads by 20% and 15%. (4) The peening process using a wide nozzle can effectively improve fatigue strength.
Formation of Metallic Micro/Nanomaterials by Utilizing Migration Phenomena and Techniques for their Applications
Authors: Saka Masumi , Tohmyoh Hironori , Muraoka M. , Ju Yang , Sasagawa K.
Published: March 2009

Migration of atoms is presented to be utilized for fabrication of metallic micro/nanomaterials by controlling the phenomenon. Two kinds of migration phenomena are treated; one is electromigration and the other is stress migration. In addition to the formation of micro/nanomaterials, some achievements in enhancing their functions are demonstrated. One is a technique to fabricate nanocoils from the formed Cu nanowires. The others are techniques to weld or cut the micro/nanowires by using Joule heating. Finally, regarding evaluation of mechanical and electrical properties of the micro/nanomaterials, the concentrated-mass cantilever technique in atomic force acoustic microscopy and the four-point atomic force microscope technique are shown to be powerful tools, respectively.
Analysis of Metals Surface Structure Modifications Induced by High Current Pulsed Electron Beam (HCPEB) under the “Heating” and “Melting” Modes
Authors: Grosdidier Thierry , Zou J.X. , Wu Jiang , Zhang X.D. , Zhang K.M. , Wu Ai Min , Hao Sheng Zhi , Dong Chuang
Published: March 2009

High current pulsed electron beam (HCPEB) is a fairly new technique for surface modifications, including hardening, alloying and formation of metastable phases. The present contribution gives some new insights on the microstructure modifications encountered at the top surface of HCPEB treated metals. In particular, the potential of the technique for structure modifications associated with the use of the pulsed electron beam under “heating” and “melting” conditions are highlighted.
Prolonged 500 °C Operation of 6H-SiC JFET Integrated Circuitry
Authors: Neudeck Philip G. , Spry David J. , Chen Liang Yu , Chang Carl W. , Beheim Glenn M. , Okojie Robert S. , Evans Laura J. , Meredith Roger D. , Ferrier Terry L. , Krasowski Michael J. , Prokop Norman F.
Published: March 2009

This paper updates the long-term 500 °C electrical testing results from 6H-SiC junction field effect transistors (JFETs) and small integrated circuits that were introduced at ICSCRM-2007. Two packaged JFETs have now been operated in excess of 7000 hours at 500 °C with less than 10% degradation in linear I-V characteristics. Several simple digital and analog demonstration integrated circuits successfully operated for 2000-6500 hours at 500 °C before failure.
Phase Formation in Ti-Al-N MAX-Phase Contacts to GaN
Authors: Borysiewicz Michał A. , Kamińska Eliana , Piotrowska Anna , Pasternak Iwona , Jakieła Rafał , Dynowska Elżbieta
Published: March 2009

Presented are the results of studies on Ti-Al-N MAX phase formation in thin film multilayers of Ti, Al and TiN deposited on n-type GaN by magnetron sputtering. Two approaches to phase formation are shown, annealing Ti-Al-TiN multilayers at 600oC in argon and annealing Ti/Al multilayers at 600oC in nitrogen. Samples are characterized by means of High Resolution X-Ray Diffraction and Secondary Ion Mass Spectrometry profiling. As MAX phases are very stable at high temperatures the potential of their application as ohmic contacts to n-GaN devices is discussed.
Vibratory communication signal produced by male western conifer seed bugs (Hemiptera: Coreidae)
Authors: Takács Stephen , Hardin Karl , Gries Gerhard , Strong Ward , Bennett Robb
Published: March 2009

We tested the hypothesis that the western conifer seed bug,Leptoglossus occidentalisHeidemann, uses a substrate-borne vibratory signal for short-range communication. To record such a signal we used computers equipped with data-acquisition hardware and software, microphones sensitive to sonic and (or) ultrasonic frequencies, membrane-type and piezoelectric speakers capable of emitting sonic and ultrasonic sound, and piezoelectric devices capable of emitting low-level, low-frequency vibrations. By tapping their abdomen on substrate, males produced a wide-band vibratory signal 20 dB (sound pressure level; 0 dB = 20 µPa) above ambient sound, with dominant frequencies of 115 ± 10 and 175 ± 15 Hz and a distinct temporal pattern. There was no evidence for (i) ultrasonic signal components; (ii) signals produced by females or nymphs, or (iii) repeated trains of signal pulses. In two-choice arena experiments, males and females preferred the played-back recording of the male-produced substrate-borne signal over silent controls, whereas nymphs showed no preference for either stimulus. In two-choice dowel experiments with hickory wood or lodgepole pine crossbeams, females (unlike males or nymphs) preferred played-back recordings of the same signal over controls. In two-choice field experiments, this signal emitted in the air by piezoelectric devices or transferred through a wire to lodgepole pine branches attracted moreL. occidentalisthan did silent controls. Our data support the hypothesis thatL. occidentalisuses a substrate-borne vibratory signal for short-range communication. The use of such a signal is consistent with reports on communication by other true bug species.
Diversity of cavity-nesting bees (Hymenoptera: Apoidea) within apple orchards and wild habitats in the Annapolis Valley, Nova Scotia, Canada
Authors: Sheffield Cory S. , Kevan Peter G. , Westby Sue M. , Smith Robert F.
Published: March 2009

Solitary cavity-nesting bees, especially trap-nesting Megachilidae, have great potential as commercial pollinators. A few species have been developed for crop pollination, but the diversity, abundance, and potential pollination contributions of native cavity-nesting bees within agricultural systems have seldom been assessed. Our objectives were to compare the diversity and fecundity of cavity-nesting bees in Nova Scotia in natural ecosystems with those in apple orchards under three levels of management, using trap nests, and to determine whether any native bees show promise for development as pollinators. Our results show that species richness and numbers of bees reared from trap nests in commercially managed orchards, abandoned orchards, and natural habitats were similar, and species’ compositional patterns were not unique to specific habitats. Trap nests can be used to increase and maintain cavity-nesting bee populations within Nova Scotia apple orchards.Osmia tersulaCockerell (Megachilidae), which accounted for almost 45% of all bees captured and was the most abundant species nesting in all habitats evaluated, should be assessed for potential as a commercial pollinator of spring-flowering crops. The influence of natural cavities on bee species richness in trap-nesting surveys is also discussed.
Life history of a secondary bark beetle, Pseudips mexicanus (Coleoptera: Curculionidae: Scolytinae), in lodgepole pine in British Columbia
Authors: Smith G.D. , Carroll A.L. , Lindgren B.S.
Published: March 2009

Pseudips mexicanus (Hopkins) is a secondary bark beetle native to western North and Central America that attacks most species of pine (Pinus L. (Pinaceae)) within its range. A pair of life-history studies examined P. mexicanus in other host species, but until now, no work has been conducted on lodgepole pine (Pinus contorta Douglas ex Louden var. latifolia Engelm. ex S. Watson). Pseudips mexicanus in lodgepole pine was found to be polygynous. Galleries were shorter, offspring smaller, and the eggs laid per niche and the potential progeny fewer than in populations from California and Guatemala. Development from the time of female attack to emergence of adult offspring took less than 50 days at 26.5 °C, and the accumulated heat required to complete the life cycle was determined to be 889.2 degree days above 8.5 °C, indicating that in the northern portion of its range P. mexicanus is univoltine. Determination of these life-history traits will facilitate study of interactions between P. mexicanus and other bark beetle associates in lodgepole pine.
Acute and chronic insecticidal activity of a new mannose-binding lectin from Allium porrum against Acyrthosiphon pisum via an artificial diet
Authors: Sadeghi Amin , Van Damme J.M. , Michiels Katrien , Kabera Anita , Smagghe Guy
Published: March 2009

In view of the increasing use of plant proteins as valuable alternatives to chemical insecticides, the susceptibility of pea aphids, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae), to three purified mannose-binding plant lectins was determined in an artificial-diet bioassay. The insecticidal activities of a new lectin, APA (Allium porrum L. (Liliaceae) agglutinin) from garden leek, were compared with those of GNA (Galanthus nivalis L. (Liliaceae) agglutinin) from snowdrop and ASA (Allium sativum L. agglutinin) from cultivated garlic. GNA and ASA showed acute toxicity to first-instar nymphs; LC50 values for GNA and ASA were 350 and 700 µg/mL, respectively. With APA, mortality was scored only at high doses. In chronic experiments, however, lower doses significantly reduced survival and fecundity of adults (P < 0.05). Aphids fed a diet containing APA at 100, 500, and 750 µg/mL showed a significant delay in reaching adulthood and no aphids survived beyond 19 days of development. The data support the potential application of APA in the integrated management of insect pests.
Pore‐scale simulations of unsteady flow and heat transfer in tubular fixed beds
Authors: Magnico P.
Published: March 2009

Small tube‐to‐particle‐diameter ratio induces a radial heterogeneity in tubular fixed beds on the particle scale. In this complex topology, theoretical models fail to predict wall‐to‐fluid heat transfer. In order to be more realistic, a deterministic Bennett method is first used to synthesize two packings with a tube‐to‐sphere‐diameter ratio of 5.96 and 7.8, containing 236 and 620 spheres, respectively. In a second step, unsteady velocity and temperature fields are computed by CFD. In the range of Reynolds number lying between 80 and 160, hydrodynamic results are validated with experimental data. The thermal disequilibrium in the near‐wall region is described in detail. Several pseudo‐homogeneous models are compared to the numerical simulations. The radial and axial profiles of temperature show a clear agreement with the model of Schlünder's research group and the model of Martin and Nilles. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Test of the relationship between sutural ossicles and cultural cranial deformation: Results from Hawikuh, New Mexico
Authors: Wilczak Cynthia A. , Ousley Stephen D.
Published: March 2009

A number of researchers have hypothesized that the biomechanical forces associated with cultural cranial deformation can influence the formation of sutural ossicles. However, it is still difficult to make definitive conclusions about this relationship because the effects appear to be quite weak, and contradictory results have been obtained when specific sutures and deformation types are compared across studies. This research retests the hypothesis using a single archeological sample of lamdoidally deformed, occipitally deformed, and undeformed crania from Hawikuh, New Mexico (AD 1300–1680). Our results show no significant difference in either the prevalence or number of ossicles between deformed and undeformed crania, suggesting that the abnormal strains generated by cranial shape modification during infancy are not a factor in ossicle development for this population. One significant relationship was detected at the right lambdoid suture in crania with asymmetrical occipital deformation. Crania that were more deformed on the left side showed greater numbers of ossicles on the right side, but the effect was small. Furthermore, the relationship may well reflect a sampling error, due to the small number of crania with greater left side deformation and scorable right side lambdoid ossicles (n = 11). Although it is possible that forms of cranial deformation other than the posterior tabular types examined here may affect ossicle expression, our review of the literature suggests that the relationship in humans is complex and incompletely understood at this time. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.
Basic skills revisited–and rewarded–in CPR's annual awards
Authors: Bleemer Russ
Published: March 2009

A rundown of the CPR Institute 25th Annual Awards for Excellence in ADR, including excerpts, as well as registration details for next month's Chicago E‐Discovery CLE training event; the release of new CPR franchise and drafting guidance, and highlights from the keynote address at CPR's Annual Meeting.
Shape‐memory polymer networks with Fe3O4 nanoparticles for remote activation
Authors: Yakacki Christopher M. , Satarkar Nitin S. , Gall Ken , Likos Roxanne , Hilt J. Zach
Published: March 2009

Shape‐memory polymers (SMPs) have recently shown the capacity to actuate by remote heating via the incorporation of magnetic nanoparticles into the polymer matrix and exposure to an alternating magnetic field. In this study, methacrylate‐based thermoset SMP networks were synthesized through free‐radical polymerization with varying amounts of Fe3O4 magnetite (0, 1, and 2.5 wt %). Furthermore, the chemistry of the networks was controlled to maintain a constant glass transition temperature (Tg) while varying the degree of chemical crosslinking. Remote heating of the networks was shown to be a direct function of the nanoparticle concentration and independent of the chemistry. Magnetite reinforcement was shown to influence the thermomechanical properties of the networks; increasing Fe3O4 concentrations led to decreases in Tg and rubbery modulus. However, networks with a higher degree of crosslinking were more resistant to thermomechanical changes with respect to magnetite concentration. Strain to failure was shown to decrease with the addition of nanoparticles and the free‐strain shape‐memory cycle was investigated for all of the networks. Networks with lower degrees of crosslinking and high magnetite concentrations showed a significant amount of irrecoverable strain. Last, the use of remotely heated shape‐memory materials is discussed in light of potential biomedical applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Keratin‐lipid structural organization in the corneous layer of snake
Authors: Ripamonti Alberto , Alibardi Lorenzo , Falini Giuseppe , Fermani Simona , Gazzano Massimo
Published: March 2009

The shed epidermis (molt) of snakes comprises four distinct layers. The upper two layers, here considered as β‐layer, contain essentially β‐keratin. The following layer, known as mesos‐layer, is similar to the human stratum corneum, and is formed by thin cells surrounded by intercellular lipids. The latter layer mainly contains α‐keratin. In this study, the molecular assemblies of proteins and lipids contained in these layers have been analyzed in the scale of two species of snakes, the elapid Tiger snake (TS, Notechis scutatus) and the viperid Gabon viper (GV, Bitis gabonica). Scanning X‐ray micro‐diffraction, FTIR and Raman spectroscopies, thermal analysis, and scanning electron microscopy experiments confirm the presence of the three layers in the GV skin scale. Conversely, in the TS molt a typical α‐keratin layer appears to be absent. In the latter, experimental data suggest the presence of two domains similar to those found in the lipid intercellular matrix of stratum corneum. X‐ray diffraction data also allow to determine the relative orientation of keratins and lipids. The keratin fibrils are randomly oriented inside the layers parallel to the surface of scales while the lipids are organized in lamellar structures having aliphatic chains normal to the scale surface. The high ordered lipid organization in the mature mesos layer probably increases its effectiveness in limiting water‐loss. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 1172–1181, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Henry Gray's Anatomy
Authors: Pearce J.M.S.
Published: March 2009

Little is generally known of Henry Gray, the author of Gray's Anatomy, and even less of his colleague Henry Vandyke Carter, who played a vital role in the dissections and illustrations leading to the production of the first volume in 1859. This essay attempts to sketch briefly the salient, know aspects of these two men and their divergent careers. It traces succinctly the subsequent fate of the unique anatomy book that has influenced and instructed almost every student of medicine. Clin. Anat. 22:291–295, 2009. © 2009 Wiley‐Liss, Inc.
Attitudes to anatomy dissection in an Irish medical school
Authors: Cahill Kevin C. , Ettarh Raj R.
Published: March 2009

Many studies around the world have looked at the stresses placed on medical students by cadaveric dissection. Although these studies have linked the use of cadavers in medical teaching to stress, some investigations have suggested an association with severe psychological stress and even post‐traumatic stress disorder. This study assessed the attitudes of medical and biomedical sciences students in an Irish medical school towards cadaveric dissection by recording, through a questionnaire, their perceptions and experience before initial exposure to dissection and subsequently examining their attitudes after the first dissection and after 9 weeks. Student attitudes towards the dissecting room remained consistently positive for the duration of the study with only a minority of respondents reporting negative symptoms. Pre‐existing attitudes to the idea of dissection were unaffected by exposure and subsequent continuous experience of dissection. The majority of students in this study did not find the dissecting room experience stressful, and considered time spent in the dissecting room valuable. However, the proportion of students with negative experiences in the dissecting room was higher than has been reported in previous studies. Many respondents felt they could be better prepared for the dissecting room experience, indicating an increasing requirement for effective preparatory programmes. Clin. Anat. 22:386–391, 2009. © 2009 Wiley‐Liss, Inc.
Cover Picture: Exploring the Implications of Vitamin B12 Conjugation to Insulin on Insulin Receptor Binding (ChemMedChem 3/2009)
Authors: Petrus Amanda K. , Allis Damian G. , Smith Robert P. , Fairchild Timothy J. , Doyle Robert P.
Published: March 2009

The cover picture shows three views of a vitamin B12–insulin conjugate bound to transcobalamin II, docked in the insulin receptor (IR). This study reveals how the structure of an orally deliverable insulin changes in solution after vitamin B12 conjugation and its effect on IR binding capacity. The results demonstrate that chemical modification of insulin by linking relatively large pendant groups does not interfere with IR recognition. For more details, see the Full Paper by T. J. Fairchild, R. P. Doyle, et al. on p. 421 ff.

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