bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Photocatalytic Activity of Titanium Dioxide-organosilicone-Heteropolyacid Photocatalysts
Authors: Piao Ming Jun , Feng Jia Ting , Li Qian Nan , Li Sheng Nan , Han Xiao Ke , Jin Xiang Guang , Hu Jiang Lei , Zhang Long
Published: August 2014

TiO2-organosilicone based hybrid catalysts functioned by Keggin-type heteropolyacid, TiO2-Si (Et)Si-H3PW12O40, were prepared via one-pot co-condensation method in the presence of a triblock copolymer surfactant (F127). The materials were well characterized by FT-IR, UV-vis DRS spectroscopy methods, and X-ray diffraction analysis to confirm the hybrid structure, to investigate correlation among TiO2-organosilicone matrix and H3PW12O40. Phtocatalytic tests show that, with a little amount of organosilicone and hybridization, the composite exhibits higher photocatalytic activity when decomposing the Rhodamine B ( RhB ) than anatase TiO2.
Study on Extraction of Mesophase from Steel Slag by Potassium Hydroxide-Sucrose (KOSH) Solution Method
Authors: Li Zhao Feng , Li Shu Cai , Zhou Zong Hui , Liu Ren Tai
Published: August 2014

The mesophase (iron aluminate, etc.) in steel slag was extracted by potassium hydroxide-sucrose (KOSH) solution method. The effects of partical size of steel slag, temperature and time of extraction on dissolution of mesophase phase were studied. The composition and morphology of the residue were analyzed by XRD and SEM. The results show the mesophase in steel slag powders (the weight was and the fineness was) could be fully dissolved when 4.00 g sample with a fineness about 600m2/kg is used and extraction temperature is kept at 90oC, however, other minerals in the steel slag could be hardly dissolved. The reason might be for that, in alkaline environment which provided by potassium hydroxide, the replacement of ions were took place between the mesophase in steel slag and the organic ligands formed by sugar and potassium hydroxide, and through the adsorption and polarization between ligand and steel slag surface, it will result in the decrease of activation energy of iron aluminate.
Study on Nano-Hydroxyapatite Assisted Preparing by Ionic Liquids
Authors: Bi Yong Guang , Xu Xu Si
Published: August 2014

Papers with Ca (NO3)2• 4H2O and (NH4)2HPO4as raw material, prepared by ionic liquids assisted nanoHAP, resulting hexagonal nanoHAP are crystal grain size are 10-20nm level, are smaller nanometer range ; specific surface area, the findings show that ionic liquids have the technology to promote the significance of the preparation method can provide a reference for large-scale preparation of biomedical nanomaterials.
Cyclic Oxidation Resistance of Co-10Cr-5Al-0.3Y Alloy at 800 oc
Authors: Bai Ling Yun , Zhang Hong Hua , Zhang Huai Shu , Zheng Yun Xiang , Xiang Jun Huai
Published: August 2014

The cyclic oxidation behavior of Co-10Cr-5Al alloys with and without 0.3 at% Y doped in atmosphere at 800oC was investigated. The addition of 0.3 at.% Y increased the oxidation rate of the alloy and changed the oxidation mechanism. The scales grown the alloys with and without Y were both composed of an outer Co2O3layer and an inner complex layer of Al2O3, Co2O3and Cr2O3, except that the addition of 0.3 at% Y enhanced the adhesion of the scale. 0.3 at% Y agglomerated in local zone which accelerated the oxidation rate and was not conductive to the oxidation process of the Co-10Cr-5Al alloy.
Ultra-Thin Shellac Fibers Fabricated Using Two Different Electrospinning Processes
Authors: Wu Yong Hui , Yu Deng Guang , Huang Shang Meng , Zha Dong Ping , Wang Meng Long , Wang Si Jia
Published: August 2014

The present study report two types of ultra-thin shellac fibers that were fabricated using a traditional single fluid electrospinning and a modified coaxial electrospinning. Ethanol was exploited as the solvent of shellac and also a sheath fluid of the coaxial process. A camera was used to observe the electrospinning processes and scanning electron microscope was taken to investigate the prepared shellac nanofibers. A single fluid electrospinning of 64% (w/v) shellac solutions not only clogged the spinneret now and then, but also resulted in fibers with a spindles-on-a-string morphology under a flow rate of 1.0 mL/h and an applied voltage of 12 kV. In sharp contrary, a coaxial electrospinning of 80% (w/v) shellac solutions (under a sheath and core flow rate of 0.2 and 0.8 mL/h, respectively, and an applied voltage of 12 kV) furnished linear nanofibers with an average diameter of 740 ± 60 nm. With the same outflows from the nozzles of spinneret, the ultrathine nanofibers from the modified coaxial process surpassed those from the single fluid process in terms of fibers’ morphology and size. The modified coaxial process described here expands the capability of electrospinning process and opens a new way to obtain thinner nanofibers with fine structural uniformity.
Transient Photoelectrochemical Analysis of the Semiconductor Properties of Oxide Films on Alloys
Authors: Tan Yu , Wang Wan Wan , Zhang Sheng Han , Liang Ke Xin
Published: August 2014

A transient photoelectrochemical analysis method is improved to investigate the semiconductor properties of oxide films on stainless steel 316L oxidized in high-temperature water. A minute amount of ZnO was added to the high-temperature water environment to alter the semiconductor properties of the oxide film deposited on stainless steel 316L. Characteristic phases in the oxide were investigated using the improved photoelectrochemical analysis method, and the semiconductor properties of the oxide film on stainless steel 316L suggested the presence of an n-type semiconductor. The photoelectrochemical dephasing angle showed movement of the flat band potential in the negative direction after ZnO addition.
The Plasma Treatment Influence on the Adhesive Wafer Bonding by the PDAP
Authors: Fang Zhong , Dong Tao , He Yong , Su Yan
Published: August 2014

This paper focus on the Oxygen plasma surface treatment affect on the bonding strength. In shearing force tests , total 10 samples were tested. Through the shear force tests, it indicates that moderate exposure to O2 plasma could increase the bonding strength to some extent. Then the AFM tests results shows that the MR-I 9100M coating topography is about 14 nm, while after Oxygen plasma treatment the topograhy decrease to 7.9 nm. And the MR-I 9150M coating topography is about 5.5 nm, while after Oxygen plasma treatment the topograhy decrease to 4.6 nm. By AFM tests, it can be found that the Oxygen plasma surface treatment cause the decrease of the surface roughness. And it puts forward another possible explanation for the Oxygen plasma treatment can improve the bonding strength.
Interaction between Enrofloxacin and the Extracellular Polymeric Substances from Platymonas Subcordiformis
Authors: Ge Li Yun , Li Shu Juan , Zhao Chang Rong , Deng Huan Huan
Published: August 2014

Extracellular polymeric substances (EPS) in marine algae-Platymonas subcordiformisaffected by enrofloxacin (ENR), the typical quinolone antibiotics released to the environment through different ways, was studied. A 3-dimension EEM (excitation –emission matrix) fluorescence spectroscopy was used to examine the interaction between EPS and ENR, and the fluorescent peaks A and B were detected, whose fluorescence intensity remarkably decreased with the increased ENR concentration. It was demonstrated that the interaction of EPS with ENR well fitted the modified Stern-Volmer. It was concluded that the presence of EPS in marine algae affected the transport and transform of antibiotics in aquatic environment.
Factor Group Analysis on the Deformed Pyrochlore-Structure Hydroxyl Transition Metal Halides
Authors: Liu Xiao Dong , Gao Sen , Meng Dong Dong , Zheng Xu Guang , Xu Xing Liang
Published: August 2014

Factor group analysis on the deformed pyrochlore-structure hydroxyl transition metal halidesM2(OH)3X(M= Co, Fe and Mn;X= Cl, Br and I) with the crystal symmetry ≡D3d5of space group No. 166 for their infrared (IR) and Raman spectroscopic studies are, for the fist time to the best of our knowledge, reported. Through a standard factor group analysis, we predict that there are 17 IR active normal modes (7A2u+ 10Eu) and 12 Raman active modes (5A1g+ 7Eg), caused by five atomic site groups [HOM3], [OM3], [MO4X2], [ClM3] and [MO6], where the black body letters represent the site atoms. In addition we figure out all the atomic displacement patterns of 12 Raman active normal modes, and point out these results are completely same as those of the famous geometric frustration material Herbertsmithite ZnCu3(OH)6Cl2.
Corrosion Rule and Amendment Method Research on the Natural Gas Long-Distance Pipeline in the Northwest Region
Authors: Guo Ren Yu
Published: August 2014

At present, transportation of the oil and gas resources in our country relies mainly on long-distance buried pipeline; pipe is commonly steel spiral welded pipe. The long-distance pipeline adopts buried way, crossing section of the complex terrain. Different soil properties, and soil have different degree and strong corrosion to the pipe, and the leakage point also is not easy to be found in time, as well as the underground pipeline maintenance needs a large number of earthwork, more hard than the construction of new line. Therefore, long-term, safe and steady operation is the main task of long-distance pipeline. How to prevent the corrosion of buried pipeline damage has long been an important part of pipeline engineering.
The Degradation of Chitosan Using Hydrodynamic Cavitation with NaNO2 Enhancement
Authors: Zhang Shu Jun , He Bing , Zhang De Li
Published: August 2014

The hydrodynamic cavitation degradation of chitosan with NaNO2enhancement was investigated. The effects of NaNO2dosage, temperature, inlet pressure, PH value, the concentration of the chitosan were been discussed. It was found that the hydrodynamic cavitation degradation of the chitosan can be largely enhanced by adding NaNO2. It was also seen that the extent of degradation chitosan can be changed marginally with the temperature.
Synthesis of Calixarene Derivatives in One Reaction System
Authors: Cao Bing Qing , Huang Qi Bin , Pan Yong , Qin Mo Lin
Published: August 2014

This paper presents a effective approach for one new supermolecule function materia preparation, 25-(thioalkyl-alkoxy)-p-tertbutylcalix [4] arene with self-assembled monolayers character was synthesized by two-step nucleophilic substitute reaction in NaH-THF phase with p-tertbutylcalix [4] arene and dibromodecne . The structure of product was characterized by FT-IR, 1H NMR, 13C NMR and MALDI-TOF-MS. The self-assembly molecular imprinted film as the sensitive film was coated on the gold delay line of SAW sensors to detect for detecting organophosphorus compounds such as sarin, had important reference value in counter-terrorism.
Adsorption and Diffusion of Aluminum, Gallium and Indium Atoms on Semi-Polar Gallium Nitride Substrate Surface: A First Principle Simulation
Authors: Yan Han , Wang Pei
Published: August 2014

The first principles simulations are performed to investigate the adsorption and diffusion of aluminum, gallium and indium atoms on semi-polar gallium nitrides surface, the calculations are performed by using the Car–Parrinello molecular dynamics (CPMD) method. The aluminum ad-atoms adsorption in path 1 and path 3 are much stable than in path 2. The maximum adsorption energy of path1, path2 and path3 are different, which reveal that a different barrier energy pathway between indium ad-atom diffuse along path 1, path2 and path3. Our calculation results reveal that diffusion barriers of aluminum, gallium and indium atoms on semi-polar gallium nitride surface are anisotropy.
Efficient Enantioselective Michael Addition of Nitroalkenes Catalyzed by a New Surfactant-Type Thiourea Organocatalyst in Water
Authors: Zhang Hong Ying , Yan Xue Ming
Published: August 2014

A new surfactant-type bifunctional thiourea organocatalysts were synthesized. In the presence of 10 mol% PhCOOH, the Michael reaction of nitroalkenes with various nucleophiles could be catalyzed smoothly by this new organocatalyst in water at room temperature, giving the desired adducts in good yields with high diastereoselectivities (syn/anti=82/18->99/1) and excellent enantioselectivities (up to 97% ee)
The Synthetic Process of Disperse Peach SE-RL
Authors: Zang Jian
Published: August 2014

Based on 1-amino-4-hydroxy-2-phenoxy anthraquinone (Disperse Red FB) and ethylene glycol phenyl ether as raw materials, polyethylene glycol (PEG) as catalyst, condensation in alkaline conditions. The optimum reaction temperature is about 140°C, 4 h reaction times, 9g catalyst, the ratio of recovery and fresh consumptions of ethylene glycol phenyl ether is controlled in 1:1 (ml). The reaction end point is easy to arrive in these conditions, and the yield of disperse peach SE-RL (Disperse Red 191) is the best, about 79.2%.
Preparation and Visible-Light Photocatalytic Activity of Cu2O/PVA/Chitosan Composite Films
Authors: Cao Chun Hua , Xiao Ling
Published: August 2014

Cu2O/PVA/chitosan composite films were prepared successfully by reduction-precipitation method and tape casting process. The composite films were characterized by TEM, SEM, XRD and FT-IR. The characterization results showed that Cu2O particles were 200-300 nm in diameter and in situ formed on PVA-chitosan blend films. The visible-light photocatalytic decolorization behavior on Cu2O/PVA/chitosan was evaluated using reactive brilliant red X-3B (X-3B) as a model pollutant. The influences of various experimental factors on X-3B decolorization were investigated. Results showed that the decolorization rate of X-3B could reach 99.8% after 50 min irradiation under the conditions of initial dye concentration 20 mg/L, catalyst amount of 0.8 g/L, H2O2 dosage of 4.04 mmol/L and pH 5.6. After composite film was reused for 5 times, the decolorization rate of X-3B could still reach more than 90% after 110 min irradiation
Nitrogen Removal by River Systems of the Feng River Basin in China
Authors: Zhi Jian Hui , Ding Ai Zhong , Zhang Shu Rong
Published: August 2014

As human activities continue to alter the global nitrogen cycle, the ability to predict the impact of increased nitrogen loading to river systems is becoming more and more important. Nitrogen retention is of particular interest because it is through its combined processes that local and downstream nitrogen concentrations are reduced. To determine the potential for N removed from Feng River network, we used stream chemistry and hydrogeo-morphology data from 17 stream and river sites to estimate NO3-–N removal in Feng River system of China. We used a N removal model to predict NO3-–N input and removal in December of 2011. NO3-–N input ranged from 0.06 to 20 kg km-1d-1in the Feng River system. Cumulative river network NO3-–N input was 446 ton year-1 in dry season in whole water system. NO3–N removal based on the model ranged from 0.04 to 4.2 kg km-1d-1 December of 2011 for Feng River. Cumulative river network NO3-–N removal predicted by the model was 58 ton year-1 in dry season. Proportional NO3–N removal (PNR) ranged from 0.2 to 0.6 in this time. PNR was negatively correlated with both stream orders.
Variation of pH during the Carbonation of CaCl2 and its Effect on the Concentration of CO32– and the Ratio of [Ca2+] to [CO32–]
Authors: Wang Yun , Zhu Shi Peng , Gan Xin Peng , Zhang Ying , Jiang Jiu Xin
Published: August 2014

The variation of pH value during the carbonation of CaCl2 solution was measured by pH meter and its effect on the dissolution of CO2 and the concentration of CO32– in the present work. Ca2+ is consumed gradually during the carbonation process, so the effect of pH value on the concentration ratio of Ca2+ to CO32– was also discussed in this paper. pH value decreases increasingly slowly as the reaction progresses. The addition of ammonia can not only improve the dissolution of CO2, but also enhance the concentration of CO32–. The concentration ratio of Ca2+ to CO32– decreases with reaction time because of no supplement in Ca2+ during the carbonation process.
The Adsorption of Chitosan-Aluminum Oxide Composite Material to Mercury Ions
Authors: Yang Yong Li , Zhao Sheng Guang , Song Chun Guang , Gao Ming
Published: August 2014

Chitosan-aluminum oxide composite material was synthesized through chemical bonds with chitosan and isopropanol aluminum as raw material, whose structure was characterized by SEM. The influence of reaction conditions on adsorption performance were studied, such as temperature, time. Results show that in the composite materials, chemical bonds were existed between aluminum and chitosan, inorganic aluminum oxide evenly dispersed in the surface of chitosan molecular. The adsorption capacity of such composite towards Hg2+ had been greatly improved better than the mixture of chitosan and Al2O3 materials and chitosan .the adsorption rate of Hg2+was 18% higher than that of chitosan, adsorption capacity is up to 900mg/g.
Coal Preparation Circulating Water Treatment Using Coarse Tail Coal-Slime as Filter Medium
Authors: Li Ji Hui , Ma Li Qiang , Li Jia Wang , Liu Qiang , Lan Cong , Jia Dong Fang
Published: August 2014

As the low economic value, many available chemical and physical properties of coarse tail coal-slime used to be ignored. In this paper, coarse tail coal-slime is used as the filer medium for the treatment of circulating water in coal preparation plants. Because coarse tail coal-slime has great adsorption performance, appropriate particle size composition and mechanical strength, it is used as filter medium for pressure feeding filtering equipment in this study, to probe the feasibility of the treatment of circulating water. The results show that with using coarse tail coal-slime as filter medium in pressure feeding filtering tank, the concentration of circulating water can be reduced to below 5 g/L, it will meet the requirements; the particle size and thickness of coarse tail coal-slime have great influence on the capacity and concentration. This method does not need settlement reagents, and it makes full use of coal preparation plant waste.
Frequency Domain Analysis and Application of Electrochemical Noise of X80 Pipeline Steel
Authors: Feng Peng Xin , Xu Wen Long , Lai Hai Tao , Zhu Xun , Lu Wen Wei , Liu Shi Xin , Yang Bin
Published: August 2014

In this paper, frequency domain analysis and application of electrochemical noise of X80 Pipeline Steel in Xinzhou Soil is researched. In the frequency data analysis of electrochemical noise, there are three characteristic parameters. It can be seen from experiments that X80 steel buried in Xinzhou soil with14% moisture content shows that metal corrosion is still not change much. And, it can be inferred that corrosion of X80 pipeline steel in Xinzhou soil with 18% moisture, corrosion is uniform while the morphology is not the uniform , it is the morphology that some pitting are connecting into the film. In Xinzhou soil with 22% moisture, potential PSD figure is different after corrosion happened for one day and three days. Thus, the corrosion type can be determined by high-frequency slope of the linear segment of potential PSD figure.
Growth of Semi-Insulating GaAs Crystal with Uniform Si Doping
Authors: Chen Shu Xian , Hou Jia Dong , Tan Xiao Ming
Published: August 2014

An improved double crucible method of melt replenishing to counteract the dopant segregation effect in order to grow homogeneous doped GaAs crystals is brought forward, and its validity and feasibility are demonstrated by analytical and numerical study. The numerical results show that the new method can suppress the increase of dopant concentration near the growth interface and can maintain the homogeneity of dopant distribution along the radial direction. The positions of replenishing melt exit almost have no effects on the axial and radial distribution homogeneity of dopant Si in the crystal. So the new method has many distinct advantages: it can improve the crystallization rate and size, the operation is flexible, etc.
Microstructural Characterization of In Situ Reaction TiB2/Zn-30Al-1Cu Composites Prepared by Spray Deposition Process
Authors: Wang Feng , Zhang Qiang , Xiong Bai Qing , Zhang Yong An , Liu Hong Wei , Li Zhi Hui , Li Xi Wu
Published: August 2014

An innovative spray deposition technique has been applied to produce in situ TiB2/Zn-30Al-1Cu composites. The microstructures of the spray-deposited composite were studied using scanning electron microscopy, transmission electron microscope and X-ray diffraction. The results have shown that the TiB2particulates are formed in the microstructure. It was found that the TiB2particles were distributed in Zn-30Al-1Cu matrix uniformly, and the TiB2particles are about 2μm in size.
Corrosion Inhibition of Polyethylene Glycol for Magnesium Alloy AZ91 at Different Temperatures
Authors: Shang Wei , Yin Zhou Lan , Wen Yu Qing , Wang Xu Feng
Published: August 2014

the corrosion inhibition of polyethylene glycol 200 for magnesium alloy AZ91 in 1% NaCl solution at different temperatures are studied. The morphology of the sample at 25°C is analyzed by SEM. And CHI600C electrochemistry workstation is employed to investigate the corrosion inhibition of the samples. The results show that the corrosion inhibition efficiency of polyethylene glycol 200 to the magnesium alloy AZ91 is affected by temperature. Polyethylene glycol 200 has superior corrosion inhibition to the magnesium alloy at the temperature of 25°C.
Saving Ladle Control Model of Steel Ladle in Steelworks
Authors: Huang Bang Fu , Shi Zhe , Zhang Gui Fang , Zhou Xiao Lei
Published: August 2014

Nowadays steelworks exists unmatched phenomenon of production rhythm between basic oxygen furnace and continuous caster, which need to saving ladle to ensure the caster casting, therefore the scientific-reasonable saving ladle control model of steel ladle could achieve energy saving significance. Based on the steel ladles of H steelworks as the research object, this article analyzes its operation process and time, matching model of basic oxygen furnace and caster. Through analyzing the relationship between the time of saving ladle and heats, the control model of saving ladle is constructed, which could calculate the reasonable time value of saving ladle, full ladle operation time and turnover cycle. Through applying Gantt chart to analysis and study the turnover rule of steel ladle, the turnover number control model of steel ladle is constructed. Satisfactory effects were obtained after applying the control model in production: saving number and turnover number were reduced, turnover ratio was increased, temperature drop was reduced.
Preparation and Characterization of Gossypol Nanosuspensions
Authors: Yang Si Tao , Tang Hui , Liu Yan Fang , Ying Xue
Published: August 2014

Gossypol (GP) is a kind of poorly water-soluble polyphenolic compounds. In this study, freeze dried gossypol nanosuspensions (GP-NS) were prepared by high-pressure homogenization and Freeze-drying technique. Bovine serum albumin (BSA) and D-alpha-tocopheryl polyethylene glycol succinate (TPGS) were used as stabilizing agents for the nanosuspensions while mannitol were used as lyophilized protecting medium. The physicochemical characteristics of the GP-NS were investigated when it was found that the mean particle size and zeta potential of the GP-NS were 217±23 nm and-21.4±2.7 mV, respectively, and the saturation solubility was 586.48±23.03 μg.mL-1. Differential scanning calorimetry and X-Ray Diffraction indicated that GP was in a crystalline state in nanosuspensions. GP-NS with a small particle size, and high saturation solubility, can be produced by the method described in this study.
A Biomimetic Approach to Enhancing Interfacial Interactions: Polydopamine-Coated Silica as Reinforcement for Epoxy Resin
Authors: Li Jian , Wen Xue Mei , Zhang Wei , Chen Yu Ping , Xiao Ying , Xiong Chen Xue , Zhu Wei , Jiang Tao
Published: August 2014

A facile biomimetic method was developed to enhance the interfacial interaction in polymer-inorganic composites. By mimicking mussel adhesive proteins, a monolayer of polydopamine (PD) was constructed on surface of silica particles through a controllable coating pathway. The modified silica (PD-silica) was incorporated into an epoxy resin. It is found that the strong interfacial interactions brought by the polydopamine benefits the effective interfacial stress transfer, leading to greatly improved flexural properties of epoxy based composites.
Synthesis of Hydroxyapatite Microspheres with Rutin as Template
Authors: Wu Hua Hong , Li Shan , Xu Guo Jie , Xiao Xiu Feng
Published: August 2014

Hydroxyapatite (HA) microspheres was successfully synthesized through biomimetic method using Ca (NO3)2·4H2O and (NH4)3PO4·3H2O as reagents and Rutin as organic substrate. The different concentration of Rutin had effect on the morphology of HA. Pore structure HA microspheres with diameter of 2μm and uniform distribution can be obtained when the concentration of Rutin was 0.01wt%. HA microspheres had smooth surface when the concentration of the template was increased. And the possible formation mechanism of HA was discussed.
Selection Research on Materials of Heat-Resistant Concrete Based on Range Theory
Authors: Xu Xing Wei , Yao Ji
Published: August 2014

Based on the technical performance index of heat-resistant concrete in a project, combined with local material performance and market supply and demand, based on the mix ratio for the concrete of strength C25, five factors as cementitious materials, admixtures, coarse aggregate, fine aggregate, admixtures were selected, every factor selected two levels, by orthogonal experiments, based on range theory, the heat-resistant concrete components that were the most suitable for the project were selected, and provided a research base for further preparation of different strength grade heat-resistant concrete.
The Higher Order Crack Tip Fields for Interfacial Crack between Linear Functionally Graded and Homogeneous Piezoelectric Materials
Authors: Dai Yao , Chong Xiao , Chen Ying
Published: August 2014

The higher order crack-tip fields for an anti-plane crack situated in the interface between functionally graded piezoelectric materials (FGPMs) and homogeneous piezoelectric materials (HPMs) are presented. The mechanical and electrical properties of the FGPMs are assumed to be linear functions of y perpendicular to the crack. The crack surfaces are supposed to be insulated electrically. By using the method of eigen-expansion, the higher order stress and electric displacement crack tip fields for FGPMs and HPMs are obtained. The analytic expressions of the stress intensity factors and the electric displacement intensity factors are derived.
Formability Discussion in Dieless Drawing of Stainless Steel Tubes
Authors: Hwang Yeong-Maw , Li Zong Sian , Lin Tsu Yu
Published: August 2014

Stainless steel tubes are widely used in various fields, such as electrode tubes, probe tubes, electronic parts, painless injection needles, and micro-nozzles etc. In this study, a self-developed prototype dieless drawing machine is used to explore the formability of the dieless drawing process of SUS304 stainless steel tubes. The critical process parameters of the forming temperature, drawing velocity, the drawing accelerations and area reduction are investigated. A commercial finite element code of DEFORM 3D is used to simulate the temperature, stress, strain distributions and drawing velocity limit in the dieless drawing process of the stainless steel tubes. The maximum area reduction obtained can reach 50% and the better forming temperatures are between 1000°C and 1100 °C.
Numerical Study of Corrugated Metal Panels Subjected to Windborne Debris Impacts
Authors: Chen Wen Su , Hao Hong , Du Hao
Published: August 2014

Hurricane, typhoon and cyclone take place more and more often around the world with changing climate. Such nature disasters cause tremendous economic loss and casualty. Various kinds of windborne debris such as compact-like, plate-like and rod-like objects driven by hurricane usually imposes localized impact loading on the structure envelopes such as cladding, wall or roof, etc. The dominant opening in the envelope might cause serious damage to the structures, even collapse. To withstand the impact of such extreme event, the requirements on panel capacity to resist windborne debris impact has been presented in the Australian Wind Loading Code (2011) [1]. Corrugated metal panels are widely used as building envelop. In a previous study, laboratory tests have been carried out to investigate the performance of corrugated metal panels subjected to a 4kg wooden projectile by considering various impact locations, impact velocities and boundary conditions. In this study, numerical models were developed to simulate the responses of the corrugated metal panels subjected to wooden debris impacts by using commercial software LS-DYNA. The predicted data from the numerical simulations were compared with the experimental results. The validated numerical model can be used to conduct intensive numerical simulation to study the failure probabilities of corrugated structural panels subjected to windborne debris impacts.
Temperature-Dependent Tension Plastic Deformation and Fracture Behavior of Ti-6.6Al-3.3Mo-1.8Zr-0.29Si Alloy at High Strain Rates
Authors: Zhang Jun , Zhang Qi Wei , Wang Yang
Published: August 2014

Titanium alloys have received great interest in the engineering applications requiring light weight and high impact resistance components. It is necessary to understand the mechanical properties of titanium alloys at high strain rates and various temperatures in the structural design. In the present paper, uniaxial tension tests at strain rates of 190, 500 and 1150s-1 and temperatures of 20, 150, 300°C are carried out using a modified split hopkinson tension bar system to investigate the effects of strain rate and temperature on tension behavior of the Ti-6.6Al-3.3Mo-1.8Zr-0.29Si alloy. Experimental results indicate that the alloy has the rate and temperature sensitivity and still keeps high strengths and toughness at temperature up to 300°C under high strain rate. SEM observations reveal that ductile fracture is the major fracture mode when the alloy is deformed at high strain rates.
Combined Compression-Shear Behavior of Aluminum Honeycombs
Authors: Ashab Asm , Ruan Dong , Lu Guo Xing , Wong Yat C.
Published: August 2014

Aluminum honeycombs are lightweight and have good energy absorption capability. They are widely used in industrial products and also as core materials in various fields of engineering such as aerospace, automotive and naval engineering because of their high specific strengths and they can undergo large plastic deformation to absorb high impact energy. In the applications of aluminum honeycombs they are not only subjected to pure compressive or indentation load but sometime also under combined compression-shear load. The mechanical response and crushing behavior under combined compression-shear loading condition is still limited in literature. In this paper, quasi-static out-of-plane combined compression-shear tests were conducted to study the deformation mechanism of different types of HEXCELL® aluminum honeycombs with different cell sizes and wall thicknesses. Three types of aluminum honeycombs were used in this study. A universal MTS machine with specially designed fixtures was employed in the quasi-static loading tests. The experiments were conducted at three different loading angles, that is, 30°, 45° and 60° and in TL and TW (T is out-of-plane direction and L, W are the two in-plane directions) plane orientation loading directions of aluminum honeycomb. The effects of different loading angle and different plane orientation are reported in this experimental study. Similarly, the effects of cell size and cell wall thickness were also analyzed.
Effect of Strain Hardening on Monotonic and Cyclic Loading Behavior of Plate-Fin Structures with Two Pore Pressures
Authors: Banno Shuhei , Okumura Dai , Ohno Nobutada
Published: August 2014

We perform finite element homogenization (FEH) analysis to investigate the effect of strain hardening on the monotonic and cyclic loading behavior of plate-fin structures with two pore pressures. As a typical base metal of plate-fin structures, 316 stainless steel is considered and assumed to be the viscoplastic material that obeys the Ohno-Wang kinematic hardening rule. The plate-fin structures are assumed to be periodic and subjected to uniaxial monotonic and cyclic loadings in the stacking direction. A periodic unit cell is used for FEH analysis. Results are compared with those based on three special cases derived from Hill’s macrohomogeneity equation. It is found that the mean pore pressure entirely affect the homogenized viscoplastic behavior. It is further found that the differential pore pressure causes the remarkable accumulation of ratcheting strain in the periodic unit cell, although this internal ratcheting gives no effect on macroscopic relations, resulting in providing a closed hysteresis loop for the plate-fin structures.
Simulation of Torsion of Thin FCC Single Crystal Wires by Mechanism-Based Strain Gradient Crystal Plasticity
Authors: Chen Yi Ping , Cai Ying Ying , Ni Q. , Zhao G.Y.
Published: August 2014

The size effects observed in the torsion of thin FCC single crystal wires is modelled by the employment of mechanism-based strain gradient crystal plasticity (MSG-CP). In the formulation the total slip resistance in each active slip system is assumed to be due to a mixed population of forest obstacles arising from both statistically stored and geometrically necessary dislocations. The MSG-CP constitutive model is implemented into the Abaqus/Standard FE platform by developing the User MATerial subroutine UMAT. By implementing the formulation, the relationship between the non-dimensional torque and the surface strain of the thin copper single crystal wires of different diameters is obtained with the [001] direction along that of the wire axis. The simulation results of torsion reveal size effects, which is in a qualitative agreement with those reported in existing literatures. An appreciable axial elongation is also found in the torsion of single crystal wires.Key words Size effect, MSG-CP model, Torsion
Crystal Plasticity Analysis of Scale Effect on Tensile Properties of Ferrite/Cementite Fine Lamellar Structure under Lattice Strain
Authors: Yasuda Yohei , Ohashi Tetsuya , Sugiyama Takuro
Published: August 2014

Tensile properties of ferrite lamella in pearlite under lattice strain are examined by a strain gradient crystal plasticity analysis. Tensile direction is made to be parallel to the lamella. Obtained results of macroscopic stress-strain relation of the lamella show significant increase of yield stress and strain hardening rate with the reduction of the lamella thickness and further increase of the yield stress with positive normal lattice strain parallel to the tensile direction in the ferrite layer. Whereas normal lattice strain perpendicular to the tensile direction contributes little to the tensile properties.
The Fabrication of a Micro-Channel for Metallic Bipolar Plates Using a Rubber Pad Forming Process
Authors: Huang You Min , Wu Yi Syun , Wang Shung Ping
Published: August 2014

A bipolar plate is one the most crucial and costliest of the various components of a proton exchange membrane fuel cell (PEMFC). It is important to reduce the cost of bipolar plate, not only in terms of material, but also in terms of the manufacturing process, to allow the commercialization of PEMFC’s. The performance of PEMFC’s is also of importance. Metallic bipolar plates have been the subject of much attention recently, because of their low material cost, formability and excellent thermal and mechanical prosperities. Therefore, this study uses a rubber pad forming process for stainless 316L steel to fabricate a bipolar plate with serpentine channels. A computational fluid dynamics (CFD) analysis is performed, in order to determine the influence of channel geometries, such as channel width, channel height and rib width, on the flow distribution of the reactant. Using the CFD results, finite element analysis models are then constructed and the formability of the micro-flow channel is studied. Finality, experiments are conducted to determine the channel height and thickness distribution of the bipolar plate. The numerical results are verified by the experimental results.
Capture of Shear Crack Propagation in Metallic Glass by High-Speed Camera and In Situ SEM
Authors: Hou Bing , Zhao Meng , Yang Pei , Li Yu Long
Published: August 2014

The dynamic double-notched experiments by using Split Hopkinson Pressure Bars (SHPB) and high-speed camera were performed on bulk metallic glass. In the double-notched experiment, shear crack propagating process was captured with the high temporal resolution of high-speed camera and the crack front propagating velocity was estimated to be 1137m/s. the shear strain/shear stress curve of BMG under dynamic loading was also obtained. Static in-situ SEM tensile experiments were included to study the multiple shear bands propagating behavior on a glassy ribbon. It was found that shear bands propagates progressively in an intermittent and discontinuous manner, and the choice of which shear bands to propagate and which ones to keep still among multiple shear bands is quite stochastic. This is explained qualitatively from the view point of energy.
Understanding the Formation Mechanism of Residual Stress during Precision Glass Moulding
Authors: Liu Wei Dong , Zhang Liang Chi
Published: August 2014

Precision glass moulding is a technique that enables the production of optical lenses of complex geometries in a single step. However, it has been reported that the product quality highly depends on the properties of a raw material, the design of a die, and the selection of a processing program. This paper aims to reveal the formation mechanism of the residual stresses by optical lens moulding. To this end, a modulus-based constitutive model was developed to integrate with the deformation and stress analyses by the finite element method. The investigation showed that the residual stresses are caused by the variability and heterogeneity of thermal expansion in a lens, but that they can be reduced effectively by decreasing the rate of cooling within the stage from the molding temperature to the glass transition temperature.
Finite Element Analysis of High Tensile Strength Steel Sheet by Using Complex Step Derivative Approximations
Authors: Uemori Takeshi , Miyake Hiroshi , Naka Tetsuo , Takiguchi Michihiro , Yoshida Fusahito
Published: August 2014

The framework for the complex step derivative approximations (hereafter CDSA) to calculate the consistent tangent moduli is studied. The present methods is one of the most effective methods to implement any material constitutive equations to the commercial finite element codes and does not suffer from calculation conditions and errors. In order to confirm the efficiency of CDSA, we developed the user subroutine code based on the CDSA using associative J2 flow rules with general nonlinear isotropic hardening rules that is commonly and widely utilized in commercial finite element codes. In this study, the user material subroutine ‘Hypela2’ of MSC.Marc (ver.2013.0.0) was utilized. The finite element calculation result by the proposal method shows a good agreement with the corresponding result by the MSC.Marc default setting. Also we apply the Yoshida-Uemori back stress model to the CDSA and evaluate this new technique to predict the deformation behavior of high tensile strength steel sheet.
Investigation into Bicycle Front Fork Forming Process of Simulation and Experiment
Authors: Chen Dyi Cheng , Ku Wen Hsuan
Published: August 2014

This study uses the three dimensional finite element code to examine the plastic deformation behavior of bicycle front fork forging. First the paper used Solid works 2010 3D graphics software to design the bicycle front fork die, and that used rigid-plastic model finite element analytical methods, and assuming mode to be rigid body. The front fork material is titanium alloy Ti-6Al-4V. A series of simulation analyses in which the variables depend on die temperature, billet temperature, forging speed, friction factors, die angle are reveal to effective stress, effective strain, die radial load distribution and damage value for bicycle front fork forming. The simulation combined Taguchi method to analysis optimization. The results of the analysis can be used to stabilize finite element software to forming front fork, and also confirm the suitability of bicycle front fork through experiment optimization.
Crystal Plasticity Analysis of Mechanical Response and Size Effect in Two Phase Alloys with Dispersion of Fine Particles
Authors: Okuyama Yelm , Ohashi Tetsuya
Published: August 2014

Plastic deformation and dislocations accumulation in a steel alloy dispersed with vanadium carbide particles is numerically analyzed by a crystal plasticity finite element technique and work hardening characteristics are discussed. Increment of dislocation density that contributes to work hardening is calculated from the mean free path of dislocations. The mean free path is defined by the spacing of forest dislocations and the average spacing of dispersed particles. Obtained yield stress and work hardening characteristics was close to that of experimental result, except that the value of work hardening rate was higher than that of experimental one.
Fabrication of Faucet Using Hydroforming and Bending Processing
Authors: Hu Hui Wen , Chen Ting Yu , Wang Sheng Yuan , Ho Tien Yo
Published: August 2014

This research aims at the development of faucet using the techniques of hydroforming and bending. In this study, a tube made from stainless steel SUS 304 is used. Finite element model, including tube, dies and punches, are established using a commercial code LS-DYNA. Tensile test is used to obtain the material properties especially in true stress-strain curve. Piecewise linear plasticity model is used to simulate the plastic deformation of material during the forming process. The initial internal pressure is designed by using the theory of thick-walled cylinder subjecting to internal pressure only. Simulation is first used to find the optimal loading conditions for hydroforming and bending forming. Experiment is then performed to fabricate the prototype of faucets using the simulated loading parameters. The results show that good correlation of the distributed thickness and profile dimension between simulation and experiment are obtained.
Finite Element Analyses of Elasto-Plastic Deformation in Pearlite Lamellar and Colony Structures
Authors: Lidyana Roslan , Ohashi Tetsuya , Yasuda Yohei , Takahashi Kohsuke , Suruga Chikara
Published: August 2014

Elasto-plastic tensile deformations in pearlite lamellar and two-colony structures are studied by finite element analyses to investigate the effects of lamellar thickness ratio and difference of lamellae orientation of two colonies in pearlite microstructure. The results obtained from plastic strain distributions in lamellar and colony structures show that plastic deformation in cementite lamellar stabilized when ferrite lamellar is thicker than cementite lamellar thickness and plastic strain concentrates when the difference between cementite lamellar orientation in two colonies are larger than 45°.
Experimental Tests of Steel Fibre Reinforced Concrete Beams under Drop-Weight Impacts
Authors: Hao Yi Fei , Hao Hong , Chen Gang
Published: August 2014

Concrete is a brittle material, especially under tension. Intensive researches have been reported to add various types of fibres into concrete mix to increase its ductility. Recently, the authors proposed a new type of steel fibre with spiral shape to reinforce concrete material. Laboratory tests on concrete cylinder specimens demonstrated that compared to other fibre types such as the hooked-end, deformed and corrugated fibres the new fibres have larger displacement capacity and provide better bonding with the concrete. This study performs drop-weight impact tests to investigate the behaviour of concrete beams reinforced by different types of steel fibres. The quasi-static compressive and split tensile tests were also conducted to obtain the static properties of plain concrete and steel fibre reinforced concrete (FRC) materials. The quasi-static tests were carried out using hydraulic testing machine and the impact tests were conducted using an instrumented drop-weight testing system. Plain concrete and concrete reinforced by the commonly used hooked-end steel fibres and the proposed spiral-shaped steel fibres were tested in this study. The volume dosage of 1% fibre was used to prepare all FRC specimens. Repeated drop-weight impacts were applied to the beam specimens until total collapse. A 15.2 kg hard steel was used as the drop-weight impactor. A drop height of 0.5 m was considered in performing the impact tests. The force-displacement relations and the energy absorption capabilities of plain concrete and FRC beams were obtained, compared and discussed. The advantage and effectiveness of the newly proposed spiral-shaped steel fibres in increasing the performance of FRC beam elements under impact loads were examined.
Dynamic Response of Polymer Based Shear Stiffening Composite
Authors: Xu Shan Qing , Ruan Dong , Miller Jason , Sbarski Igor , Kapoor Ajay
Published: August 2014

In this paper, the uniaxial dynamic compressive response and rheological properties of a newly developed commercially available polymer based shear stiffening (PSS) composite is experimentally studied at different crushing velocities. The results showed that the compressive stress of PSS composites increases with the rising strain rates. Comparing the stress-strain curves of PSS composites and neoprene at the same strain rate, it was found that the compressive stress of PSS composite increased gradually with strain, while the compressive stress of neoprene increased sharply with strain. The uniaxial dynamic mechanical analyses of PSS composites showed that storage modulus of PSS composite increased with the increase of sweep frequency. The rheological study of PSS composites showed that the storage modulus of PSS composite significantly increased when the angular frequency was higher than a critical value, e.g., 100 rad/s, demonstrating evident shear stiffening properties.
A Newly Developed Clamping Device for the Tension/Compression Test at Various Strain Rates
Authors: Joo Geun Su , Choi Min Kuk , Huh Hoon
Published: August 2014

The tension/compression hardening behavior is important in sheet metal forming processes because of complicated loading paths. Experimental methods to measure the tension/ compression behavior have not considered the effect of the strain rate although the strain rate is related to the hardening behavior of sheet metal. The tension/compression tests need to be conducted considering the strain rate to acquire accurate hardening behavior.This paper deals with an experimental technique to measure the tension/compression behavior of sheet metal at various strain rates. A new clamping device was developed to prevent a sheet specimen from buckling under compression loading condition. Compared to previous clamping devices, the clamping device was devised to uniformly impose a clamping force and easily measure the strain from side of a specimen. Tension/compression tests have been conducted at various strain rates for SPCC and DP590 with displacement of 10%. Hardening curves under the tension or compression loading condition were obtained and analyzed with respect to the strain rate.