bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the Manufacturing of Zirconia Cutting Square Tools by PIM and Hot Isostatic Pressing Process and Test Cutting
Authors: Heo Young Moo , Chang Sung Ho , Shin Kwang Ho
Published: June 2012

The purpose of present study was to increase productivity and to reduce the polution of dust for making of endmill by conventional method such as grinding process. The micro scale endmill manufactured by powder injection molding, the molding (green part) was debinded and sintered. After that decreasing the porosities of the parts sintered, HIP process was adapted. After HIP process the relative density was shown more than 99% of the tools sintered. Finally, the micro cutting experiment using manufactured tool by PIM and HIP were implemented for verifying the feasibility of the tool. The ware of zirconia micro tool was observed very small, but the concentricity is less than the conventional tool made by grinding process. This type of tool is adequate to use in rough milling.
A Study on the Effect of High Calorie Diet on Stress Alleviation
Authors: Roh Sang Gyun , Lee Jae Gook
Published: June 2012

In this study, we tried to reveal the presence of a cytokine that is regulated by weight, food intake, body fat, the hypothalamus-pituitary-adrenal axis, and corticosterone. The experiment group was given a high calorie diet and the control group was fed a normal calorie diet, and both groups were exposed to various stresses. The behavioral and hormonal change by the kinds and severity of stresses were measured via their immunologic aspect as well as their stress alleviation by voluntary high calorie food intake. After sacrificing the animal, the adrenal gland fat tissues were weighed, and the high calorie diet group showed heavier adrenal glands than those of the control group. In particular, the CVS A group had lighter adrenal gland weight than the Res B and CVS B groups, and the other groups had heavier adrenal glands. The comparison of plasma ACTH concentration to the corticosteroid secretion ratio showed that the CVS A group had decreased ACTH and an increased corticosteroid/ACTH ratio. This fact shows that the adrenal gland was highly active and, in spite of a normal corticosteroid concentration, induced too much negative feedback inhibition.
Fabrication and Surface Hardening Properties for SiC/AlN Ceramic Composites with Different SiC Grain Size
Authors: Jin Hai Yun , Huang Zhen , He Bo , Gao Nai Kui , Shao Liang , Qiao Guan Jun
Published: June 2012

In this research, the SiC/Al/h-BN composite ceramics with different SiC grain size were fabricated by the method of preparing the machinable pre-sintered body through Plasma Activated Sintering (PAS), which has the advantage of complex shape formation for precision parts. By hardening treatment, the SiC/Al/h-BN composite ceramics would be changed to SiC/AlN composites, and the relatively higher hardness and mechanical properties could be obtained accordingly. The phase transformation and microstructure were observed and the mechanical and other properties were also measured. The results showed that, for different matrix SiC particle size, change tendency of the bending strength was different with the heat treatment temperature change. And the bending strength of composites with larger SiC grain size was higher than that with smaller SiC grain size.
Defects Diagnosis Technology of Water Supply Pipe's Network Using Pipe Endoscope Camera of High Resolution/High Pressure Resistance Performance
Authors: Lee Hyun Dong , Kwak Pill Jae , Lee Joo Yeon , Park Chul Han , Ko Ja Yong , Cho Myoung Hun
Published: June 2012

The size of pipe network accident caused by aging of water distribution system, rapid urbanization, abnormal climate or a disaster such as an earthquake is gradually becoming larger. Accordingly, it is required to improve the technology to maintain the water distribution system so that the related technologies can be scientifically and systematically applied. The paradigm of Korean water supply service is changing from supply era to maintenance era, and it is required to apply equipment and method to effectively check, diagnose and test the internal condition of the pipe without stopping water supply. If photographing and diagnosis of the burial environment around the water service pipeline and inside the pipe can be carried out without stopping water supply effectively utilizing the surrounding facilities such as straight piping and air valve to the maximum, decrepit pipe (defective pipe) improvement projects can be effectively carried out by making adequate decisions. Also, a systematic and more efficient water supply service maintenance system can be established by building a database of surrounding pipeline directly investigated and selecting priority of direct/indirect evaluation. This study has raised accuracy of a diagnosis by applying a camera capable of securing high resolution without generation of distortion in case of photographing the inside of a pipe, and suggested an application method of the pipe endoscope camera using an inspection hole inside a pipe.
Effect of Aluminum Addition on the Static Recrystallization Behavior of Magnesium
Authors: Kim Keun Joon , Ha Tae Kwon
Published: June 2012

Recrystallization kinetics of Mg alloy has been investigated in this study. Mg alloys such as Mg-3Al and Mg-6Al in weight percents were cast into rectangular shaped ingots of 20mm thickness. Solution treatment at 400°C for 24 hrs has been carried out on these ingots and pure Mg for comparison. Heat treated ingots including pure Mg were rolled at room temperature by thickness reductions of 10, 20, and 30 percents. Annealing treatment for recrystallization has been conducted on these cold-rolled plates at temperatures of 200, 300, and 400°C for various times from 1 min to 24 hrs. The microstructure observation and hardness measurement conducted on the recrystallized specimens revealed that static recrystallization at 200°C was very slow and expedited with increasing temperature, regardless of Al contents. While recrystallization behavior of Mg at 300°C appeared to be retarded by increase in Al contents, that of Mg was not affected at 400°C.
A Study on Thermal Conductivity and Mechanical Properties of Al-Zn-Mg Aluminum Alloys
Authors: Shin Je Sik , Ko Se Hyun , Kim Ki Tae
Published: June 2012

In this paper, it was aimed to develop a new Al-Zn-Mg base aluminum alloy having high electrical conductivity, strength, and formability simultaneously. As a result, Al-Zn-Mg base low aluminum alloy sheet can be effectively strengthened without significant thermal conductivity loss by multiply alloying precipitation hardening elements and properly controlling production process parameters.
A Study on Surface Oxidation Coating Characteristic of Al-Si Casting Alloys
Authors: Shin Je Sik , Kim Bong Hwan , Lee Sang Mok
Published: June 2012

in this paper, it was aimed to improve understanding about the effects of physical melt treatment on the morphologies of eutectic silicon crystal size, and then the effects of these microstructural features on anodizing characteristics. A380 and A356 casting aluminum alloys were used in this experiment. A twin-screw melt-shearing process and an electro magnetic stirring process were utilized before high pressure die casting. In order to refine and homogenize the microstructure of the diecast Al-Si alloys, the melt-shearing process parameters were controlled and T6 heat treatment was carried out. A uniform microstructure over the whole thickness of the diecast specimens caused smaller difference in oxidation coating layer thickness between machined and non-machined surfaces. More uniform anodic coating layer was obtained by AC/DC coupled anodizing and PEO processes compared to conventional DC anodizing process.
Effect of Deep Cryogenic Treatment on Microstructure of 5A06 Aluminum Alloy MIG Welded Joint
Authors: Gao Shan , Wu Zhi Sheng , Jin Peng Fei , Wang Jun Jie , Shuai Peng
Published: June 2012

5A06 aluminum alloy welding was obtained by using SAlMg-3 as welding wire with MIG (metal inert gas arc welding). The welded joint with deep cryogenic treatment at liquid nitrogen temperature (-155) for 4h, 8h, 10h were analyzed by metallographic and XRD examination. The results have shown that a lot of subgrain appears in the microstructure of the welded joint resulting in the refined grain after cryogenic treatment. The obvious increasing in content ofβ-phase (Mg2Al3) is distributed and dispersed evenly, contributed to dispersion strengthening of the welded joint. Meanwhile, orientation phenomena is obtained for some grain after deep cryogenic treatment. As a result, the microstructure of the joint can be modified by the deep cryogenic treatment.
Synthesis of ZnO Nanorods with Tunable Aspect Ratio
Authors: Zhang Li Yan , Wang Fen , Zhu Jian Feng
Published: June 2012

ZnO nanorods were prepared by heat treating of aqueous zinc acetate treated with organic of PVA. The products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The results indicate that the as synthesized ZnO are hexagonal wurtzite nanorods with the maximum aspect ratio of 10:1 (100 nm in diameter and about 1 μm in length). The morphology of nanorods was formed by the regulation of appropriate organic under a pH value of 8.5. The growth mechanism of ZnO is proposed that the nanocrystals grow along a preferred direction in a growth tunnel provided by organics.
Hydrogen Permeability of NiO-Doped Alumina with Nickel Composites Membrane
Authors: Shon Bo Young , Jung Mie Won
Published: June 2012

NiO-doped Al2O3was synthesized with 20 wt% of nickel nitrate using the sol-gel process. P123 as an organic additive added to increase surface area of powder. The phase transformation, thermal evolution and surface morphology of the powder were characterized by XRD, TG-DTA and FE-SEM. The 20 wt% NiO-doped Al2O3/10 wt% Ni composite membrane was prepared by hot press sintering (HPS) following with a mechanical alloying process. Hydrogen permeation flux for 20 wt% NiO-doped Al2O3/10 wt% Ni membrane was obtained as 0.1 mol/m2s at 673K.
Development of Dynamically-Formed Membranes Using Colloidal Silica and Kaolin
Authors: Yun Taek Gun , Kim Yun Jin , Lee Sang Ho , Sohn Jin Sik , Choi June Seok
Published: June 2012

Low pressure membranes such as microfiltration (MF) and ultrafiltration (UF) have been widely used for water and wastewater treatment. However, most MF and UF membranes are made of polymeric materials, leading to limited resistance to external streeses. Ceramic membranes are also used but they are more expensive than the polymeric membranes. In this study, novel inorganic membranes were developed for water treatment applications. Colloidal silica and kaolin were used to form dynamic membranes. Stainless steel filter was used as supports for the dynamic membranes. Laboratory-scale systems were used to evaluate their potential and performance. Water permeability and turbidity removal were monitored to confirm their initial efficiency and long-term stability.
Preparation and Characterization of Polyethylene/Ethylene Vinyl Acetate Composite Non-Dropping Greenhouse Film
Authors: Wei Jia Cheng , Luo Xue Gang , Lin Xiao Yan , Zhang Hong Ping
Published: June 2012

For the problem it is easy for the film to generate fog and drop in greenhouse, Polyethylene/Ethylene Vinyl Acetate (PE/EVA) composite greenhouse film was prepared by co-blending and extrusion. The impact of preparation parameters and the dosage of anti-fogging and anti-dropping masterbatch on the mechanical properties and non-dropping properties of the film has been investigated by versatile mechanical testing machine, atomic force microscope (AFM), contact angle tester, water bath acceleration method. The results show that the elongation at break and tensile strength of the composite film, contact angle of water and the film have decreased after added the anti-fogging and anti-dropping masterbatch. The addition of the anti-fogging and anti-dropping masterbatch can increase the non-dropping property of the greenhouse film greatly.
Study on Microstructure and Mechanical Properties of Porous Si3N4 Ceramics
Authors: Yu Fang Li , Bai Yu , Du Jun , Yu Ping Ping , Wang Jian Zhi , Yang Jian Feng
Published: June 2012

Porous Si3N4ceramics were fabricated by using different species β-Si3N4as seeds, 5 wt.% Y2O3and Lu2O3as sintering additives. Effects of three types of β-Si3N4seeds and two types of sintering additives on the microstructure and mechanical properties of porous Si3N4ceramics were investigated. The results showed rod-like β-Si3N4grains with finer and high aspect ratio developed in the porous microstructure. The microstructure and mechanical properties of specimens added with Lu2O3and β-Si3N4seeds were better than which of those added with Y2O3and β-Si3N4powder. The flexural strength and average aspect ratio of porous Si3N4ceramics were in the range of 297349 MPa and 5.757.26 with the porosity range of 41.07%44.40%.
Characterization of Cold-Rolled Nickel Electroplated Copper Sheet
Authors: Lee Jung Il , Hong Chang Woo
Published: June 2012

The electroplating of nickel on the copper sheet for lead tap, which is one of the important parts of the secondary battery, has been conducted to improve functional properties such as electrical, thermal and mechanical properties. Materials used for secondary battery parts were known manufactured as cladding methods with different kind metal bonding by cold-roll process. In this study, the nickel was electroplated on the copper sheet and cold rolled and heat treated to evaluate the functional properties and to determinate the grain growth orientation and to investigate the texture formation. Grain growth direction and texture formation were analyzed by the X-ray pole figure. The influence of texture on the mechanical properties could be quantitatively confirmed by the results from the orientation distribution function and the tensile test. The heat-treated textures of the cold-rolled hybrid copper sheet were also investigated.
Fabrication and Characterization of Alumina/Zirconia Ceramic Compound
Authors: Cho Bum Rae , Chae Ji Hoon , Kim Bo Lang , Kang Jong Bong
Published: June 2012

Sintered ZTA(zirconia toughened alumina) which has good mechanical properties at a low temperature was produced by milling and mixing with Al2O3 and ZrO2(3Y-TZP). In order to examine the effect of sintering aids on the mechanical properties of ZTA, fracture toughness and hardness of the produced ZTA were observed in accordance with change of the added quantity of ZrO2 Scanning electron microscopy and X-ray diffraction technique were applied to observe microstructural change and phase transformation during the process. Experimental results showed that the addition of sintering aids in ZTA at a low temperature induced densification and adding SiO2 and talc lowered sintering temperature and promoted crystallization process of the compound. The mechanical strength of ZTA added ZrO2 showed higher mechanical strength and SEM analysis revealed that Al2O3 and ZrO2 during the sintering process restrained the grain growth each other. Especially, the 92% Al2O3 added sintering aids showed more than 98% of the theoretical density and more than 1500 Hv of hardness value at a low temperature of 1400. It was also showed that the fracture toughness is gradually increasing first and decreasing later in accordance with the quantity of ZrO2.
Removal of Isopropyl Alcohol (IPA) Using Anodized Photocatalytic Metal Membrane Reactor
Authors: Kim Jong Oh , Choi Won Youl , Lee Yong Woo
Published: June 2012

This study was conducted to investigate the effect of operational parameters in anodized photocatalytic metal membrane reactor (PMMR) for the removal of Isopropyl alcohol in electric wastewater. The effect of UV light type, the strength of UV light, the injection of TiO2 powder and air flowrate was investigated. About 70% of removal of IPA under the condition of UV irradiation (UV-C, 64W) in combination with an anodized TiO2 metal membrane was achieved within 180 minutes treatment, indicating that the UV/anodized photocatalytic TiO2 metal membrane process is a promising treatment technology for treating IPA in electric wastewater.
Research of Assembled Monolithic Compound Spiral Reinforced Concrete Column Encased by Steel Plate Hoop and Jointed by Bolts
Authors: Li Jin , Li Xiao Jie , Li Qing Ning , Jiang Wei Shan , Ying Yi Hui
Published: June 2012

The assembled monolithic compound spiral reinforced concrete column in this paper is consisted of two concrete columns reinforced by high-strength compound spiral hoop and jointed by encased steel and bolts. Experiments of four specimens under low cyclic loading and different axial compressive loads are carried out, and the result testifies that the anti-seismic property of this measure is not worse than the integral compound spiral hoop columns under the same load.
Shot Peening Characteristics of Cold-Rolled Mo Sheet
Authors: Cho Gue Serb , Choe Kyeong Hwan , Lee Won Beom
Published: June 2012

The commercial pure Mo sheet was shot peened to increase high-temperature mechanical and thermal resistance. Shot peenining was conducted on the surface of cold-rolled Mo sheet with 0.4MPa of shot pressure. The hardness of bcc Mo sheet was increased with increase of shot peening time. Surface hardenss is gradually increased to 120s at the 0.4MPa pressure, but the profiles become almost flat at the prolonged time. The grains were deformed and work hardened in the surface layer. The surface roughness was also increased with peening time. The grain size of shot-peened Mo sheet was smaller than that of cold-rolled Mo sheet in the all recrystallization temperature range. The reason for this could be a larger density of nucleation sites caused by the higher surface deformation of shot-peened Mo sheet. Mo2C carbide phase was analyzed on the surface of recrystallized Mo sheet at the secondary recrystallization temperature range. It was considered that molybdenum carbide was formed due to the evaporation of graphite heating element in the hot-zone furnace. From this study, shot peening of Mo sheet could be a good cold work hardening method to improve high-temperature mechanical and thermal resistance properties.
Preparation and Mechanism of Nano-TiO2 Coatings on Poly(p-phenylene-benzobisoxazole) (PBO) Fiber
Authors: Luan Yan Yan , Liu Xue Feng , Peng Zhan Nan , Xie Jian Xin
Published: June 2012

nanoTiO2/PBO composite fiber was prepared with a chemical method by depositing nanoTiO2 on the surface of PBO fiber which was treated by silane coupling agent. The process parameters on the preparation of nanoTiO2/PBO composite fiber were optimized according to the interfacial adhesion between the composite fiber and epoxy resin, and the coating mechanism of nanoTiO2/PBO composite fiber was also discussed. The results show that the uniform nanoTiO2/PBO composite fiber with high interfacial adhesion can be prepared on the PBO fiber which was pretreated by silane coupling agent with a concentration of 1.5 % for 35 min at room temperature, in which the nanoTiO2 aqueous solution with a concentration of 1.0wt% was ultrasonic dispersed for 1h in alkaline environment (pH 11), and then the PBO fiber was immersed in the dispersed solution at 60 °C for 6 h to prepare nanoTiO2/PBO composite fiber. The single fiber pull-out strength of the prepared composite fiber was increased by 85.28 % compared with that of the untreated PBO fiber. Silane coupling agent was a bridge of PBO and nanoTiO2, hydrogen bond association and like dissolves like were attributed to the improvement of interfacial adhesion between nanoTiO2 and PBO fiber.
Effect of TiC Content on the Microstructure and Mechanical Properties of Ti3AlC2/Al2O3 In Situ Composites Synthesized by Hot Pressing
Authors: Ye Lan , Zhu Jian Feng
Published: June 2012

The Ti3AlC2/Al2O3 in situ composites were successfully synthesized from the system of Ti-TiC-Al-TiO2 by reactive hot pressing at 1350 °C. The effect of TiC content on the phase composition, microstructure and mechanical properties were investigated in detail. The results indicate that the fabricated products possess the highest purity as the TiC contents reduce to 90 % of its theoretical content. This deviation is mainly attributed to the decomposition of Ti3AlC2 and vaporization of Al at high temperatures. The effect of TiC content on the fracture toughness, flexural strength, Vickers hardness of Ti3AlC2/Al2O3 composites was also discussed in detail.
Effects of Sintering Conditions and Additives on Translucent Silicon Nitride Ceramics
Authors: Yang Wen Wu , Inada Miki , Tanaka Yumi , Enomoto Naoya , Hojo Junichi
Published: June 2012

Translucent β-Si3N4sintered ceramics have been fabricated by using AlN-MgO sintering additives. In the present study, the authors employed AlN-MgO as a standard sintering aid, and investigated the effects of sintering conditions on the translucency of Si3N4. Furthermore, various oxides such as HfO2, Sm2O3, Y2O3, Sc2O3, La2O3, Nd2O3, CeO2, CaO, ZrO2etc. were used as the sintering aids of Si3N4, and the sintered β-Si3N4ceramics exhibited different transmittances in the visible region. It was found that the transmittance of sintered ceramics was mainly affected by the sintering additives.
The Dynamic Recrystallization of Hot-Deformed Austenite in a Micro-Alloyed Steel
Authors: She Yuan , Zhang Zhao Hui , Yang Jun , Ju Jian Tao
Published: June 2012

As the dynamic recrystallization (DRX) behavior of hot-deformed austenite is the basis of determining controlled rolling schedule for steel, in the present work, the dynamic recrystallization behavior of austenite of a 0.22%C-1.30%Mn-0.04%Nb micro-alloyed steel was investigated by means of high temperature compression tests on the Thermecmastor-Z simulator. By the analysis of true stress-strain curves at different deformation stages, the hot deformation equation of austenite was established for the steel. As a result, the energy to induce recrystallization of austenite for the steel is 419.1 kJmol-1, as it was influenced by the drag effect of micro-alloyed element Nb in solid solution. The ratio (σc/σp) of critical stress σc (where DRX occurs) to peak stress σp is 0.93 while the ratio (εc/εp) of critical strain εc to peak stress εp is 0.52 for the steel. The austenite grain size of dynamic recrystallization of the micro-alloyed steel is refined by decreasing the deformation temperature and improving the stain rate.
Molten Salt Synthesis of Mullite Whiskers from Silicon Carbide Precursor
Authors: Wang Wei , Liu Gui Wu , Qiao Guan Jun , Yang Jian Feng , Li Hong Wei , Guo Ya Jie
Published: June 2012

Mullite whiskers were prepared from SiC powders in molten Al2(SO4)3-Na2SO4 mixture salts at different temperatures. The morphology and phase composition of resulting whiskers were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) techniques. Mullite tiny fiber clusters with diameter about 50 nanometers and lengths of over several microns were obtained in 900°C mixture molten salts system. A new oxidation-dissolution mechanism was proposed for explanation mullite whiskers growth.
Effect of Solution Treatment on Microstructure and Properties of the SAF2507 Super Duplex Stainless Steel
Authors: Liu Jin Ming , Liu Jie , Fan Guang Wei , Du Dong Fang , Li Guo Ping , Chai Cheng Jun
Published: June 2012

Effect of solution treated temperature at 5001100°C on ferrite/austenite ratio and σ phase precipitation has been studied in this paper, and the tensile properties after solution treatment at 950°C and 1050°C is compared. The results shows that the ferrite/austenite ratio treated 1050~1100°C is about 1:1; and the formation of σ phase occurs in the ferrite or at ferrite - austenite boundary. The quantity of the σ phase precipitation increases firstly and then decreases with increase of the solution treatment temperature, reaching the maximum at 900°C, and disperse at above 1050°C. Tensile tests show that the fracture is brittle divided and stretched by ductile belt at 950°C, and ductile at 1050°C.
Microstructure Evolution during Combustion Synthesis of Ni/Ni-Aluminide Laminated Composites
Authors: Guo Ya Jie , Shi Zhong Qi , Li Hong Wei , Liu Gui Wu , Qiao Guan Jun
Published: June 2012

Combustion reaction in laminated Ni and Al foils was ignited by plasma activated sintering (PAS) to synthesize metal-intermetallic laminated composites (MILCs). The microstructure evolution in the reaction and the post-heat treatment was investigated. The results showed that thermal explosion (TE) reaction were happened between Ni and Al foils at the melting point of Al. The reaction was incomplete due to the heat loss through the thick foils. The produced phases, Ni2Al3 and NiAl3, were converted to a compositionally gradient series of intermetallic phases in the nal microstructures of the intermetallic layers after the post heat treatment.
Drawing and Property of 316L Extra Fine Stainless Steel Wires
Authors: Liu Shi Feng , Xu Ping , Wang Bo Jian
Published: June 2012

The purpose of this paper is to study the compression ratio per pass, drawing rules of three differential commercial 316L stainless steel wires during drawing extra fine stainless steel processing. In addition, the influence of chemical composite on the mechanical property has been discussed as well. The results indicate that the tensile strength of austenite stainless steel wires was increased obviously by multi-passes drawing. The strength-enhancing effect of wire drawing can be substantial.
Effect of Impact Angle on Erosion Wear Behaviours of SiCp/Cast Iron Surface Composite
Authors: Lu Zhen Lin , Jin Han , Zhou Yong Xin , Xie Hui
Published: June 2012

The slurry erosion wear performances of the SiCp/cast iron surface composite, which was prepared by infiltrating molten cast iron into SiC particles preforms, were studied on self-made slurry inject erosion wear machine. The results show that the erosion wear rate of the SiCp/cast iron surface composite would be the lowest at impact angle of 30°, and the largest at impact angle of 60°. The erosion wear rate increases gradually when impact angle is changed from 30° to 60°, and then decreased with increasing the impact angle. The erosion wear mechanism of the SiCp/cast iron surface composite is dominated by cutting and grooving at low impact angle, and by fatigue spalling and cutting at high impact angle. For the gray cast iron, the erosion wear rate of would be increased gradually with the increase of impact angle, reaching the peak value at 90°, which indicates the typical characteristics of brittle material in slurry erosion wear process.
Experimental Study on Intensified Leaching of Vanadium Ore
Authors: Zhu Jun , Guo Ji Ke , Xue Jing Jing , Li Xin
Published: June 2012

The wet technology for vanadium extraction from the complex refractory vanadium ores was studied as a preferred approach with phosphoric acid as helper leaching agent. The results showed that the addition of phosphoric acid could improve the vanadium leaching rate significantly. Combination with sulfuric acid, high amount of phosphoric acid and high leaching temperature can promote the leaching of vanadium. With the sulfuric acid concentration of 425.6 g/L, leaching temperature of 90 °C, leaching time of 4 h and liquid-solid mass ratio 2:1, the vanadium leaching rate of 90 wt.% can be achieved. Meanwhile, about 15% of the consumption of sulfuric acid could be reduced with 39 wt.% phosphoric acid.
Precipitation Behavior of High-Nitrogen Low-Nickel Austenitic Stainless Steel at Intermediate Temperature
Authors: Zou De Ning , Liu Rong , Li Jiao , Wu Kun , Liu Xiao Hua
Published: June 2012

The precipitation behavior of nitrides and carbides occurred in aging process for 10Cr21Mn16NiN austenitic stainless steel at intermediate temperature was investigated by use of thermodynamic calculation, metallography and electron microscopy analysis. The precipitates evolved from chain-like initiatively along grain boundaries at lower aging temperature, to that along grain boundaries and inside the grain of austenite with more content as the temperature rising gradually. When aging at 800 °C, precipitates became layered tablet shaped and the composition was ascertained the mixture of Cr2N and M23C6. At a certain temperature, the volume fraction of precipitates for the aged testing steel by air cooling was slightly higher than that by water quenching.
The Effect of Porosity of CBN Grinding Tools on Grinding Properties
Authors: Yang Xing Hua , Yang Jian Feng , Bai Jian Guang , Xu Sao Chun
Published: June 2012

The CBN grinding wheels with different porosity, which used 100/120 CBN grind grain and 15μm glass powder as main starting materials, pore creating material as auxiliary material, were prepared by conventional sintering technology; Used GCr15 bearing steel which quenching hardness was 60HRC as ground materials, investigated the effect of porosity of CBN wheel on its cutting ability. In this paper , the metal removal rate was measured by electronic analytical balance, surface roughness of GCr15 was analyzed used LEXT laser scanning confocal microscope and the surface topography of grinding face was observed used scanning electron microscope. The investigated results showed that the metal removal rate acutely increasing with the porosity of wheels increasing in same loading weight, it reached 0.445g/min with 41% porosity in 3500g loading weight, at the same time, the difference of surface roughness caused by variation of porosity of CBN grinding wheel was slight, it did not severely lower machining precision of workpiece.
Preparation and Microstructure of Biomorphic Hydroxyapatite Using Extracted Beech Wood Template
Authors: Hou Guang Ya , Jin Zhi Hao , Qian Jun Min , Zheng Guo Qu
Published: June 2012

Biomorphic hydroxyapatite (Bio-HA) was fabricated using extracted beech wood that was impregnated with HA sol followed by sintering at 600~1300 °C for 2 hours. The extraction using boiling 5% ammonia solution was helpful to bring more pores to benefit to impregnation of the HA sol into wood templates. The weight changes of the exacted wood sample with HA gel, phase formation and microstructures evolution of resulting products were investigated by TGA, XRD and SEM. The main weight loss occurred below 600 °C. The biomorphic HA sintered at 1100~1300 °C were three dimensions and connective pores structure, in which the main tracheid pores with diameter of 60~80 μm derived from beech wood template and the small pores with 1~8 μm in the strut walls resulted from the sintering process. Bio-HA faithfully retained the woods porous structure. The method provided a novel candidate for fabricating a porous scaffold suitable for bone tissue engineering applications.
Influence of Composition of Gd-Doped Ceria Electrolyte on Performance of Solid Oxide Fuel Cell
Authors: Ibusuki Yuta , Hirata Yoshihiro , Sameshima Soichiro , Matsunaga Naoki
Published: June 2012

Cell performance was measured for four types of Ni (40 vol%)-Gd-doped ceria (GDC) anode-supported solid oxide fuel cells with GDC electrolyte (40-120 μm thickness) of Ce1-xGdxO2-x/2 compositions (x = 0.05, 0.1, 0.15 and 0.2) at 773-1073 K using a H2 fuel. (La0.8Sr0.2)(Co0.8Fe0.2)O3 cathode was printed on the GDC films. The open circuit voltage and maximum power density at 873-1073 K showed a maximum at x = 0.1. The maximum power density at x = 0.1 was 166 and 506 mW/cm2 at 873 and 1073 K, respectively. The excess oxygen vacancy at x = 0.1-0.2, which does not contribute to the oxide ion conductivity, reacts with a H2 fuel to form electrons (H2 + VO 2H+ + VO×, VO× VO + 2e-). This reaction reduces the cell performance.
Low Temperature Molten-Salt Synthesis and Characterization of Nanocrystalline Mullite Whiskers from Coal Gangue
Authors: Wu Xiu Lan , Zhao Dan , Zhu Jian Feng , Ren Qiang
Published: June 2012

The high purity mullite whiskers were successfully prepared via molten-salt synthesis (MSS) method using eutectic salt Na2SO4 as the flux at a relatively low temperature of 1100 °C for 3 h from a mixture of coal gangue and Al2(SO4)3·18H2O. The phase formation and microstructure of the as synthesized whiskers were characterized via differential scanning calorimetry (DSC), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The influence of Na2SO4 content on the morphology and size of the resulting mullite whiskers were also investigated in detail. The results indicate that the as fabricated mullite whiskers are dispersed uniformly with a diameter of 43-69 nm and a relatively large aspect ratio of more than 30.
Nano Composite Membranes of Sulfonated Poly(ether sulfone)s Containing DHTPE and SiO2 for PEMFC
Authors: Lim Young Don , Seo Dong Wan , Lee Soon Ho , Hossain Md. Awlad , Lee Hyun Chul , Jung In Seok , Kim Whan Gi
Published: June 2012

Sulfonated poly (ethersulfone) s (S-PDHTPEs) were prepared from 4,4-(2,2-diphenylethenylidene) bisphenol (DHTPE), 4,4-sulfonyldiphenol, 4-fluorophenylsulfone using potassium carbonate, and followed sulfonation reaction with conc. sulfuric acid. DHTPE is a conjugated structure, which enables to form planar conformation between aromatic rings, and selectively sufonated on phenyl rings of polymer side chain. Composite membranes were prepared with copolymers and SiO2nanoparticles (20 nm, 4~10%wt). The composite membranes were cast from DMSO. A series of composite membranes structures and characteristic were evaluated by the1H-NMR spectroscopy, and thermal stabilities. The membranes were performed by ion exchange capacity (IEC), water uptake and proton conductivity as a function of degree of sulfonation.
Research on Electrothermal Properties of a Composite Carbon Fiber Paper
Authors: Zhou Jun , Wu Lei , Lan Xin Zhe , Zhang Qiu Li , Chen Xiang Yang , Zhao Xi Cheng
Published: June 2012

The effect of different factors, such as carbon fiber content, temperature, electrifying time and frequency, power density on the electrothermal properties of the composite papers with different carbon fiber content was researched. The results show that the resistivity of the composite papers decreases with the increasing of carbon fibers. The current-voltage relationship is in good conformity with the Ohm's law. The negative temperature coefficient and good reversibility are shown during the heated and cooled process of the papers. The resistance of the papers decreases gradually with electrifying time and trends to stable after several hours. On-off electrifying times on its resistance have little effect in the long term. The curve of power density and surface temperature shows a good linear behavior.
Effect of Heat Treatment on Microstructures and Hardness of SiC/Steel Armor Composite
Authors: Dong Jie , Pan Jie , Wang Miao , Zhang Cong Rong , Liu Wei , Lv Zhen Li
Published: June 2012

The SiC reinforced ferrous based armor composites were treated with three heat treatments of annealing, isothermal quenching and annealing. The relationships between the treatment processing and the microstructures and hardness of the composite material were investigated. The results revealed that the heat treatment had scarcely any influence on the reinforced component but there appeared iron silicide existing at the interface of the two component, and the hardness of the component changed in three same treatment situation, the highest hardness of the matrix reached 532HB after subjecting to the isothermal quenching at 300°C.
Effect of Temperature and Carbon Contents on the Synthesis of β-SiC from Silicon Sludge by Direct Carbonization Method
Authors: Kwon Woo Teck , Kim Soo Ryong , Kim Y. , Lee Yoon Joo , Won Ji Yeon , Park Won Kyu , Oh Sea Cheon
Published: June 2012

β-SiC powder was synthesized using silicon sludge from photovoltaic silicon-wafer production by varying heat treatment temperature and carbon contents. The synthesized β-SiC powder and silicon sludge was analyzed by XRD, SEM, FT-IR and Particle size analysis. It is known that the conversion of SiC from the mixture of Silicon and Carbon is mainly affected by the mole ratio of C/Si and heat treatment temperature. In this study, the influence of reaction temperature and carbon contents on the synthesis of β-SiC from silicon sludge was examined.
The Relationship between Viscosity and Electrical Conductivity of CaF2-SiO2-Al2O3-CaO-MgO Slag System
Authors: Ju Jian Tao , Lu Zhen Lin , Jiao Zhi Yuan , Yang Jun , Zhang Zhao Hui
Published: June 2012

The relationship between the viscosity and the electrical conductivity of CaF2-SiO2- Al2O3-CaO-MgO slag system was deduced through theoretical calculation and experiment. The experiment was designed by quadratic orthogonal rotary regression method. The slag viscosity and conductivity were measured at 1600, and the constant (C) was calculated. The calculating model between each component mass fraction and constant C was performed, and the stability of calculating model was also verified by representative slag. The results showed that the calculating constant (C) of regression model is in good agreement with experimental values. Thus, the relationship between refining slag viscosity and conductivity using the formula at certain temperature is feasible.
Failure Analysis of ERW Seam Weld Pipeline in Internal Pressure
Authors: Wang Rui , Li Dong Feng , Yang Peng , Han Jun , Han Xin Li
Published: June 2012

Fracture failure behavior of the electric resistance welding (ERW) seam weld of Φ355.6×10.3 mm L360 in high internal pressure was investigated in this paper. The mechanical, metallurgical and fractographic characteristics were studied to clarify the reason of fracture failure for the ERW seam weld. The experimental results showed that the impurity and flaw of weld area were the main factors for the failure of ERW seam weld in high internal pressure. The impurity and flaw in welds had great effects on the mechanical characteristics of ERW. The approaches to ensure the integrity of the pipeline in service were proposed.
The Behaviors of Removing Silver Ions by Low-Cost Expanded Rice Husk, Nature Diatomite and Nature Bentonite as Sorbents
Authors: Liang Xuan , Luo Xue Gang , Lin Xiao Yan , Mei Qiang
Published: June 2012

Low cost industrial and agricultural by-products are promising materials for water pollution treatment such as removal of heavy metals. This work deals with removal of silver ions from solutions using expanded rice husk (ERH), nature diatomite (ND) and nature bentonite (NB). Firstly the influence of pH value of the solution on adsorption capacity for silver ions was studied, and then the effect of initial silver concentration on adsorbents adsorption capacity was investigated. The silver ions removal percentage increases with initial pH and achieves a maximum value of nearly 94% at pH= 5.0 ± 0.5 for ERH. The maximum adsorption capacity is 18.6 mg/g for ERH.
Investigation of Microstructure and Mechanical Properties of Friction Stir Lap Jointed Ni Base Superalloy
Authors: Song Kuk Hyun , Nakata Kazuhiro
Published: June 2012

This study evaluated the microstructure and mechanical properties of friction stir welded lap joints. Inconel 600 and SS 400 as experimental materials were selected, and friction stir welding was carried out at tool rotation speed of 200 rpm and welding speed of 100 mm/min. Applying the friction stir welding was notably effective to reduce the grain size of the stir zone, as a result, the average grain size of Inconel 600 was reduced from 20 μm in the base material to 8.5 μm in the stir zone. Joint interface between Inconel 600 and SS 400 showed a sound weld without voids and cracks. Also, the hook, along the Inconel 600 alloy from SS 400, was formed at advancing side, which directly affected an increase in peel strength. In this study, we systematically discussed the evolution on microstructure and mechanical properties of friction stir lap jointed Inconel 600 and SS 400.
A Study on the Synthesis of SiC Powder from the Silicon Sludge of the Photovoltaic Industry
Authors: Kwon Woo Teck , Kim Soo Ryong , Kim Y. , Lee Yoon Joo , Jung Eun Jin , Park Won Kyu , Oh Sea Cheon
Published: June 2012

β-SiC powder was synthesized directly from silicon sludge with carbon black. Large amount of silicon sludge is generated from Solar Cell industry. In an environmental and economic point of view, recycling silicon sludge is important. In this study, two kinds of silicon sludge were characterized using XRD, SEM/EDS and FT-IR. SiC powder was synthesized by the reaction of ball-milled silicon powder for 3h in vacuum at different temperatures (1350 and 1600). Physical properties of the heat treated SiC have been characterized using a SEM, XRD, Particle size analyzer and FT-IR Spectroscopy.
Studies on Adsorption of Strontium (II) by Expanded Rice Husk
Authors: Tang Yun Qiang , Lin Xiao Yan , Zhang Ya Ping , Luo Xue Gang
Published: June 2012

The expanded rice husk, a low-cost and environmental friendly absorbent, was used to remove Sr2+ from the simulated radioactive wastewater. The adsorption behaviors for the radionuclide ion Sr2+ was studied, and effects of various parameters including pH, temperature, expanded rice husk dose, initial concentration of Sr2+ and adsorbed time on the removal rate of ion Sr2+ from the simulated radioactive wastewater were evaluated. Results show that Sr2+ can be successfully removed from the simulated wastewater by the expanded rice husk, and the removal rate of ion Sr2+ on the expanded rice husk achieves as high as 99.37%, which is much higher than that on activated carbon (42.50%) at optimized conditions.
Effect of Gelatinization on Morphology and Thermal Properties of Polyvinyl Alcohol-Corn Starch Blend Films
Authors: Li Ji Wei , Luo Xue Gang , Lin Xiao Yan , Li Xian Hong
Published: June 2012

The blend films of ungelatinized and gelatinized starch/polyvinyl alcohol (PVA) were prepared by solution casting method. Their morphologies and thermal properties were analyzed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). A droplet phase was observed in the blends containing ungelatinized starch and a laminated phase was observed in the blends containing gelatinized starch. For both ungelatinized and gelatinized starch/PVA blends the melting temperature (Tm) (210230) of PVA was detected, and the Tm of gelatinized starch/PVA blends was higher than that of the ungelatinized starch/PVA blends. TGA results showed that over the rst 300 the weight loss for ungelatinized starch/PVA blends was higher than that for gelatinized starch/PVA blends, however the gelatinized starch/PVA blends showed the greater weight loss after scanning up to 400. Different morphologies and thermal properties of two types of blends were attributed to the different hydrogen bonding interactions between starch and polyvinyl alcohol.
Adsorption of Bromic Acid Ion in Water by the Reduced Titanium Oxide
Authors: Watanabe Eiji , Nishizawa Kaori , Tazawa Masato
Published: June 2012

Because bromic acid ion generated by the ozone processing of drinking water for sterilization is strong carcinogenic, there is a high possibility in persons health hazard. The titanium dioxide was reduced at 900-degree Centigrade by the gas atmosphere (CO or H2). It was found that the concentration of the bromic acid ion in water was decreased at time when the reduced titanium oxide was added to water including the bromic acid ion. The bromic acid ion in water could be adsorbed by the titanium oxide reduced. In addition, it was suggested that the bromic acid ion could be decomposed into the bromide ion with low carcinogenic by using the photocatalitic function of titanium oxide under UV irradiation.
Spin-Polarized Current in the Magnetic Nano Wire
Authors: Habashi L. Babazadeh , Kanjouri F. , Esmailian A.H.
Published: June 2012

We calculate the TMR of a quantum nanowire with circle cross section consisting of two ferromagnetic electrodes separated by an insulator based on the nearly-free-electron approximation. The dependence of TMR to applied voltage by different cross-sections of nanowire and different electron effective mass of nanowire are studied theoretically.
Theoretical Investigation of the Magnetic Order in FeAs
Authors: Dobysheva Lyudmila V. , Arzhnikov Anatoly K.
Published: June 2012

The magnetic structure of the iron monoarsenide FeAs is studied using ﬁrst-principlescalculations. We consider the collinear and non-collinear (spin-spiral wave) magnetic orderingand magnetic anisotropy. It is analitically shown that a magnetic triaxial anisotropy resultsin a sum of two spin-spiral waves with opposite directions of wave vectors and diﬀerent spinamplitudes, so that the magnetic moments in two perpendicular directions do not equal eachother.
Spin Hall Effect Induced by Sound
Authors: Lyapilin I.I.
Published: June 2012

Transport of electronic spins in low-dimensional and nanoscale systems is the subject of thenovel and quickly developing eld of spintronics. The possibility of coherent spin manipulationrepresents an ultimate goal of this eld. Typically, spin transport is strongly aected by couplingof spin and orbital degrees of freedom. The inuence of the spin orbit interaction is twofold.The momentum relaxation due to the scattering of carriers, inevitably leads to spin relaxationand destroys the spin coherence. On the other hand, the controlled orbital motion of carrierscan result in a coherent motion of their spins. Thus, the spin orbit coupling is envisaged as apossible tool for spin controling in electronic devices. In particular, it is possible to generatespin polarization and spin currents by applying electric eld, the phenomenon known as thespin-Hall eect (SHE) [1- 3]. The eect is manifested in the form of a spin current directedperpendicular to the normal current, which takes place in an electric eld.
Magnetic Structure of La0.54Ho0.11Sr0.35Mn1-XCuxO3 Manganites
Authors: Craus M.L. , Anitas E. , Cornei N. , Islamov A. , Garamus V.
Published: June 2012

New La0.54Ho0.11Sr0.35Mn1-xCuxO3 manganites were obtained by sol-gel method using oxides and acetates and sintered finally in air at 12000 C for 15 h. The samples were studied by X-ray diffraction, magnetic and electric methods. Space group, lattice constants, average size of the crystalline blocks and positions of cations/anions in the unit cell, were determined using the FullProf code. The samples contain only a perovskite phase with an orthorhombic structure (Pnma space group). Small-angle neutron scattering (SANS) measurements were performed on the SANS-1 setup at the FRG-1 reactor of the GKSS Research Centre (Geesthacht, Germany). The sizes of magnetic clusters have been determined at room temperature.
Response of a Manganite-Based Magnetic Tunnel Structure to Microwave Radiation
Authors: Volkov Nikita V. , Rautskiy M.V. , Eremin E.V. , Patrin G.S. , Kim P.D. , Lee Chan Gyu
Published: June 2012

We demonstrate that a magnetic tunnel structure irradiated by microwaves can generate a significant voltage signal due to the rectification effect. The measurements were carried out using current-in-plane geometry with a current flowing parallel to the interfaces in the structure. A value of the microwave-induced voltage strongly depends on a bias current and can be driven by a magnetic field. The rectification effect is discussed both in classical terms of nonlinearity of the current-voltage characteristic and using a mechanism that involves the interplay between the spin-polarized current and magnetization dynamics in the magnetic tunnel structure.
Electro-Assisted Magnetization Switching in Asymmetric Spin-Valves
Authors: Sohatsky V.
Published: June 2012

The magnetic and electric properties of Fe/Cu/Fe sandwiches deposited on Si were studied in order to improve the efficiency of such a model of spin transistor with a spin-valve. Evaluations of the energy balance and measurements of current dependence on voltage and applied magnetic field confirmed the possibility of amplification increasing in case of additional effect of current on remagnetization.