bluuebunny/crossref_metadata_2025 huggingface dataset:
Tribological and Oxidation Properties Study of a Kind of Sulfonate-Modified Nano Na2CO3 and K2CO3
Authors: He Zhong Yi , Xiong Li Ping , Wang Jun Xiao , Qiu Jian Wei , Fu Xi Sheng
Published: August 2011

The tribological properties of a middle base value metal alkali sulfonate-modified nano Na2CO3 and K2CO3 as lubricating oil additives were introduced in this paper, and its collaboration with the ashless antioxidant properties were evaluation by using PDSC. The results show that the product possesses good tribological properties, thermal stability, and a good synergistic antioxidation effect with ashless antioxidant, it mainly to increase oxidation free energy of base oil.
Barium-Free Glass-Ceramic Sealants from the System CaO-MgO-B2O3-Al2O3-SiO2 for Application in the SOFC
Authors: Theerapapvisetpong Apirat , Jiemsirilers Sirithan , Thavorniti Parjaree , Conradt Reinhard
Published: August 2011

The planar solid oxide fuel cell (p-SOFC) is a promising configuration of a high-T fuel cell. Barium alumosilicate glass ceramics are suggested to use as sealants by many authors since these materials seem to meet the requirements to establish a hermetic and electrically insulating seal between the steel components of the SOFC. However, in long-term application, the formation of BaCrO4 may degrade the interfacial strength between glass-ceramics and metallic interconnect and disrupt the cell components. In this work, a series of barium-free glass-ceramics in the system of CaO-MgO-B2O3-Al2O3-SiO2 were prepared. The selected compositions were located within the constitutional range of åkermanite – forsterite –anorthite. The thermal properties including glass transition temperature (Tg) and crystallization temperature (Tc) of the produced glasses were measured. The effect of boron oxide additions was studied in order to optimize the softening and flow behavior. For the experiments, a hot – stage microscope was used. Some glass compositions were mixed with high – CTE akermanite powder in order to increase their CTE after sintering. The CTE of the investigated materials after sintering at 900 °C, 2 h, ranged from 10.5 to 11.8 10−6 K−1.
Catalytic Oxidation of Toluene over Fe2O3/Al2O3 Catalyst
Authors: Miki Takeshi , Tai Yutaka
Published: August 2011

Fe2O3/Al2O3 catalyst was prepared and the catalytic oxidation of toluene over the catalyst was investigated. The catalyst was prepared by wet impregnation of commercial alumina support. The support was impregnated with an aqueous solution of iron nitrate. The wet support was dried and calcined at 600-800 °C. The catalytic property of the catalyst was measured by the light-off curve of CO2 yield. All these catalysts were active for total oxidation of toluene above 250 °C. The catalytic activity of catalyst calcined at 600 °C was better than those of catalysts calcined at 700 and 800 °C.
Characterization of CuO/ZnO/Al2O3 Catalyst for Methanol Synthesis
Authors: Zhou Jun , Lan Xin Zhe , Luo Wan Jiang , Song Yong Hui , Zhang Qiu Li , Tian Yu Hong
Published: August 2011

The property of CuO/ZnO/Al2O3 catalysts for methanol synthesis was investigated by means of XRD, H2-TPR and DTG. The results show that the thermal activity of the self-made CuO/ZnO/Al2O3 catalyst is better than the commercial catalyst C302 and displayed stable property after 180h application. The catalyst calcinated revealed strong interaction between CuO and ZnO, and the dispersion of CuO crystal particular was uniform. There was a small amount of carbon deposition on the surface of CuO/ZnO/Al2O3 catalyst after synthesis reaction. For synthesis of methanol with self-made catalyst in fixed reactor from the analog components of reformed bluecoke furnace gas, the space time yield and selectivity of coarse methanol respectively reached 1.5451 g·g-1·h-1 and 99.6143% under the conditions of temperature of 240°C, pressure of 5.5MPa and space velocity of 12000h-1.
Comparison of Sonochemistry Method and Sol-Gel Method for the Fabrication of TiO2 Powder
Authors: Choi Jinhyuk , Cho Sung Hun , Kim Tae Ho , Lee Soo Wohn
Published: August 2011

Sol-gel with sonochemical process and sol-gel method were used for the fabrication of photocatalytic TiO2 powder and the properties of the TiO2 powder thus prepared were examined and compared. For the synthesis of TiO2 powder, the starting material was Ti-butoxide and H2O and the reaction was carried out at 80 °C in a sol-gel method. On the other hand, Ti-butoxide was reacted with H2O in an ultrasonic frequency of 23 kHz with ultrasonic powers of 800 W for two hours. After evaporation, 24 hours aging time was kept at 400 °C in both cases, the final product appeared was the anatase phase. Ultrasonic chemical method was found to be excellent for flocculation and crushing effects where as in sol-gel method, the product obtained was of high purity and high homogeneity. Sol-gel with sonochemical process has found to be excellent for flocculation and crushing effects. From Sol-gel method, the size of TiO2 particles produced were found to be about 20 nm, spherical, homogeneous while severe agglomeration. In contrast, by sonochemistry method, the size of TiO2 particles produced were about 10 ~ 22 nm size and it has shown more photocatalytic activity than sol-gel sample which is about 28.7 % greater efficiency
Adsorption Studies of Nitrobenzene onto Aminated Lignin
Authors: Lin Xiao Yan , Zhang Jian Ping , Luo Xue Gang , Zhang Chi
Published: August 2011

Adsorption performance of aminated lignin (AmL) for nitrobenzene (NB) removal was investigated through batch experiments. The results showed that AmL possessed strong adsorption ability for NB with hydrogen bond interaction. The equilibrium adsorption data were well represented by the Freundlich isotherm model and the saturated adsorption capacity could reach 24.2mg/g. The adsorption process was found to follow pseudo-second-order kinetics. The maximum adsorption of NB on AmL occurred around the neutral pH.
Photocatalytic Activities of Transition Metal-Doped TiO2 Nano-Powders by Sonochemical Method and their Physicochemical Properties
Authors: Choi Ah Young , Tokutaro Yamaguchi , Cho Sung Hun , Han Chul Hee
Published: August 2011

With respect to metal doping into TiO2, the doping limits for V, Cr, Zr, Nb, Mo, and W are predicted to be higher than other transition metals according to the binding energy calculations in a unit cell model of anatase TiO2, which suggests that Cr and W can be doped into anatase structure more easily than Ag or Pt, for example. Our investigation has twofold research objectives. One is to prepare metal-doped TiO2 nano-powders from these transition metals, and the other is to test photocatalytic activity of each resulting powder. For the former, sonochemical process has been used to produce Cr-doped, W-doped, Ag-doped, and Pt-doped TiO2 nanoparticles. For the latter, we have performed photocatalytic oxidation of methylene blue. The combined results of the morphology and photocatalytic activites have enabled characterization of the physicochemical properties of these transition metal-doped nanoparticles.
Photocatalytic Decolorization of Methylene Blue by Ferric Stearate, Ferrocene and NiDBC under Sunlight Irradiation
Authors: Zhao Zhao , Luo Xue Gang , Lin Xiao Yan
Published: August 2011

In this work, ferric stearate, ferrocene and nickel N,N-dibuty dithiocarbamate (NiDBC) were utilized as photocatalyst for the decolorization of methylene blue (MB) aqueous solutions under sunlight irradiation. Pure MB solution was used as reference. Absorption intensities and surface morphology of these photocatalyst were investigated by Diffuse Reflectance Spectroscopy (DRS) and Scanning Electron Microscopy (SEM).The study indicated that ferric stearate had minimal promotion to the decolorization of MB aqueous solutions; and ferrocene exhibited better photocatalysis ability after had been irradiated 60 hours. In this study, NiDBC showed the best photocatalysis ability from the beginning. Furthermore, NiDBC enhanced the decolorization of MB after been irradiated for 31 hours. And after being irradiated 270 hours, the MB aqueous was completely decolorized by NiDBC.
Relationship between Chemical Composition and the Amount of Phosphorus Adsorbed
Authors: Watanabe Eiji , Nishizawa Kaori , Maeda Masaki
Published: August 2011

Relationship of the adsorption behaviors of phosphorus with several natural materials and artificial HAS-clay with various chemical compositions was investigated. The amounts of phosphorus adsorbed by them were closely related with the contents of aluminum in the material. It was found that the higher the aluminum contents of material, larger the amount of phosphorus were adsorbed.
Separation of Cobalt from Zinc Sulfate Solution by Novel Oxidant
Authors: Li Lin Bo , Xue Juan Qin , Hong Tao , Yang Jun , Wang Xing
Published: August 2011

The separation of cobalt from zinc sulfate solutions by oxidation-precipitation process using peroxy-monosulfuric acid as oxidant has been presented according to the technological conditions of removal of cobalt from zinc electrolyte. After investigating the important parameters governing the separation of cobalt and their effect on the separation process, the optimal parameters of oxidation precipitation of cobalt were determined, the oxidation precipitation percent of cobalt was up to 90% under the conditions. The XRD analysis results of precipitates demonstrated that the precipitate was cobalt hydroxide oxide (CoOOH) in pure cobalt system while the precipitates were cobaltosic oxide (Co3O4) and basic zinc sulfate (ZnSO4(OH)6.H2O) in zinc-cobalt system.
Texture Development in Cold Rolled and Annealed Ta
Authors: Song Kuk Hyun , Kim Han Sol , Kim Won Yong
Published: August 2011

In order to investigate the texture development in cold rolled and annealed tantalum (Ta), the present study was carried out. For this work, cold rolling was performed up to ~ 96% reduction in thickness, and annealing was performed at elevated temperature up to ~ 1200 °C for 60 min under the high vacuum to prevent the surface oxidation. As a result, increase in the reduction ratio of the cold rolled Ta was effective to develop the a fibre texture, with its texture components such as (001)<110> and (112)<110>. Also, resulting grain size was more refined by increase in reduction ratio, consequently, 96% cold rolled and annealed material showed the best refined grain size. However, in case of annealed material, g fibre texture with its texture component, such as (111)<121> and (111)<112>, was developed by increase in annealing temperature. In this study, we systematically discussed the texture development due to the increase in reduction ratio.
Theoretical Study for the Interaction of Chitosan and Sulfate
Authors: Xue Juan Qin , Ma Xiao Na , Wang Yu Jie , Wen Dan Dan , Yang Jun
Published: August 2011

Choosing the basis of 6-311++G (d. p) with chitosan as its model, we use the density functional B3LYP method to optimize the structure and calculate the energy for the chitosan and sulfate. We study the adsorption for the sulfate from different adsorption point (amidogen, hydroxide and carbon-ring) with or without the protonation of chitosan amidogen. Through a comparative analysis of the bond-lengths, bond-angles, charges and binding energies before and after the interaction of chitosan and sulfate, we find that the adsorption of chitosan for sulfate is mainly the adsorption of amidogen after protonation. The adsorption mode is the combination of sulfate with two amidogens after protonation.
Effect of Annealing on the Properties of Surface Nanocrystallized CP-Ti
Authors: Zhang Cong Hui , He Xiao Mei , Lan Xin Zhe , Zhao Xi Cheng
Published: August 2011

Vacuum annealing was carried out for the SMAT treated CP-Ti sample at different temperatures. The structure and the properties of the SMAT sample before and after the annealing were analyzed by means of the optical microscope, hardness and polarization curve testing. The results show that, when the annealing temperature of surface nanocrystallized CP-Ti treated CP-Ti (SMAT) was below 350°C, the microstructure and hardness of nanostructured surface was stability, and its corrosion resistance was improved compared to non-annealing one. In particular, the corrosion resistance at 150°C was better than that of the original CP-Ti.
Structure and Dielectric Properties of Bi0.5K0.5TiO3-SrTiO3 Lead-Free Ceramics
Authors: Ruangphanit Anucha , Phetnoi Prapapim , Niemcharoen Surasak , Muanghlua Rangson
Published: August 2011

Bismuth potassium titanate – strontium titanate (1-x)Bi0.5K0.5TiO3-(x)SrTiO3 (BKT-ST) lead-free ceramics when x = 0-0.20 were synthesized by the solid state reaction method with normal sintering. The ferroelectric phase transition was studied by X-ray diffraction (XRD). All compositions showed a single phase perovskite structure with tetragonal symmetry at room temperature and the phase structure transformed from ferroelectric tetragonal – paraelectric cubic in the range of x ³ 0.10 . Dielectric study revealed that the dielectric relaxor behavior was induced with increasing ST and transition temperature (Tm@εr max) of ST-doped BKT had a tendency to decrease with increasing ST. The Bi0.5K0.5TiO3 – SrTiO3 system was expected to be a new and promising candidate for lead-free capacitors.
Effect of Microcrystalline Cellulose from Banana Stem Fiber on Mechanical Properties and Crystallinity of PLA Composite Films
Authors: Suchaiya Voravadee , Aht-Ong Duangdao
Published: August 2011

This work focused on the preparation of the biocomposite films of polylactic acid (PLA) reinforced with microcrystalline cellulose (MCC) prepared from agricultural waste, banana stem fiber, and commercial microcrystalline cellulose, Avicel PH 101. Banana stem microcrystalline cellulose (BS MCC) was prepared by three steps, delignification, bleaching, and acid hydrolysis. PLA and two types of MCC were processed using twin screw extruder and fabricated into film by a compression molding. The mechanical and crystalline behaviors of the biocomopsite films were investigated as a function of type and amount of MCC. The tensile strength and Young’s modulus of PLA composites were increased when concentration of MCC increased. Particularly, banana stem (BS MCC) can enhance tensile strength and Young’s modulus of PLA composites than the commercial MCC (Avicel PH 101) because BS MCC had better dispersion in PLA matrix than Avicel PH 101. This result was confirmed by SEM image of fractured surface of PLA composites. In addition, XRD patterns of BS MCC/PLA composites exhibited higher crystalline peak than that of Avicel PH 101/PLA composites
Effect of Artificial Aging on Aluminum Extrusion Alloy for Automobile Bumper
Authors: Kim Sun Dae , Cho Hoon , Kim Do Hyang
Published: August 2011

The heat-treatable, precipitation-hardening, aluminum alloys are of special interest for automobile where high strength and dent resistance are required, and for bumpers, where good strength and shock absorption are needed. In both cases, good formability is also an important requirement. The heat-treatable 6000-series Al-Mg-Si alloys have been the material of choice for automobile. Despite the high strengthening potential of Al-Mg-Si alloys, processing factors such as the artificial aging processes, as well as the duration of artificial aging, can seriously impede the strengthening process. The highest tensile strength of A6082 alloy was obtained when Mg/Si atomic ratio is set to 1.1 due to the biggest volume fraction of intermetallic compound containing Mg and Si. It was to determine how aging process affected the microstructure and mechanical properties of the A6082 alloy as different ratio between Mg and Si.
Effect of Sodium Carbonate Addition on the Property and Formation of Terracotta Panel
Authors: Wang Bao Hua , Shen Liang , Wang Qiong
Published: August 2011

The extrusion property of the paste has a significant effect on the production of terracotta panel. The influence of sodium carbonate addition on the exchange ability of ions, thickened hydrate film with the sodium cations and the plasticity of mud pie was investigated. When the addition of sodium carbonate is 0.015%wt, the plasticity and yield strength of paste are excellent. The best performance specimen with 0.015% sodium carbonate has a few fluctuation of effective strain and the ratio of the maximum with the minimum velocity of paste is the least while extruding from meatus of discharging.
Control of Microstructure and Texture for Mechanical Properties of Mg-Al-Zn Alloys
Authors: Jeong Ha Guk , Lee Jong Beom , Kim Yong Geun
Published: August 2011

In Mg-Al-Zn alloy sheets, the grains were refined from 30 mm to 2 mm during the process of differential speed rolling at 473 K, having approximately the same size dominate at a high thickness reduction rate of 60 %. In addition to these microstructural changes, the rolled sheets showed a weaker texture characterized by pole than those of commercial sheets. The DSR sheets have equal value of elongation at 0, 45, and 90 degrees from the rolling direction. With the mechanical properties, the results of Erichsen test indicate that DSR process remarkably enhanced ductility of the present Mg alloy sheets at room temperature.
Cu Particles Deposition onto MWCNTs by Chemical Reaction
Authors: Cho Gue Serb , Lim Jung Kyu , Jang Hoon , Choe Kyeong Hwan , Lee Won Sik
Published: August 2011

CNTs were decorated with Cu particles to decrease floatation of CNTs and improve the wettability between CNTs and Al melt by chemical reaction method. The as-received size of multi-wall CNTs with 99.5% purity was 10~20nm in diameter and 20um in length. Before Cu deposition, the purified CNTs were suspended in solvent solution and ultrasonically stirred to improve the dispersion of CNTs in the copper chloride solution. The metallic Zn and Zn/CNTs composite powders were added into the suspension to precipitate Cu onto the CNTs surface. The Cu deposited CNTs have been characterized in respect of dispersion and size changes of CNTs and Cu particles with field emission scanning electron microscopy(FESEM). The deposited Cu particles onto the CNTs surface were in the range of 100~300nm in diameter. Also, the application of high ultrasonic treatment improved the full coverage of CNTs surface with Cu nanoparticles. From this study, the multi-wall CNTs have been deposited and embedded with Cu particles by chemical reduction process.
Eco-Glass Based on Thailand Quartz Sands and Bismuth Oxide
Authors: Won-In Krit , Pongkrapan Sorapong , Dararutana Pisutti
Published: August 2011

Ecological glass with non-toxic was fabricated in bismuth-bearing glass using mainly local quartz sands and various concentration of bismuth oxide. The specific gravity (SG), refractive index (RI), thermal expansion coefficient (CoE) and hardness (HV) were determined. It was found that the values of SG, RI and HV were increased linearly as the increasing of bismuth oxide, whiles that of CoE was decreased. This glass is environmentally friendly materials.
Effects of Fabricated Method on the Coefficient of Friction of Al2O3-15 wt% ZrO2-3 wt% Solid Lubricant Composites
Authors: Kim Seung Ho , Cura M. Erkin , Söderberg Outi , Hannula Simo Pekka , Lee Soo Wohn
Published: August 2011

The coefficient of friction was very important factor for the applications of high temperature parts. In vehicles, the coefficient of friction was decreased due to lubricants as like engine oil etc. Lubricant such as oils is difficult to apply at high temperature. To apply high temperature parts, lubricants were demanded for high temperature stability. This work is to use the pulsed electric current sintering (PECS) technique and the atmospheric plasma spraying (APS) method in order to make self-lubricating Al2O3-15wt% ZrO2-solid lubricant composites. We focused on the coefficient of friction for the fabrication method of self-lubricating Al2O3-15wt% ZrO2-solid lubricant composites. We compared with the coefficient of friction of PECSed and APSed composites. The surface roughness of PECSed Al2O3-15wt% ZrO2-solid lubricant composites were 0.06 ~ 0.31 μm of Ra and 10.16 ~ 33.12 μm of Ry. In the case of APSed Al2O3-15wt% ZrO2-solid lubricant composites, as-coated samples were 6.56 ~ 11.42 μm of Ra and 59.68 ~ 81.79 μm of Ry, and polished samples were 1.12 ~ 3.70 μm of Ra and 11.66 ~ 32.22 μm of Ry. The coefficient of friction of PECSed and APSed Al2O3-15wt% ZrO2-solid lubricant composites were 0.19 ~ 0.49 and 0.41 ~ 0.61, respectively.
Effect of Heat Treatment Temperature and Atmosphere on Micro Structure of Polyphenylcarbosilane
Authors: Kwon Woo Teck , Kim Soo Ryong , Kim Jong II , Lee Yoon Joo , Bhave Ramesh R. , Kim Y.
Published: August 2011

Polyphenylcarbosilane (PPCS) was synthesized from thermal rearrangement of the polymethylphenylsilane around 350 ~ 430°C. Characterization of synthesized PPCS was performed with FT-IR spectroscopy analysis. From FT-IR data, the band at 1035cm-1 is very strong and assigned to CH2 bending vibration in Si-CH2-Si group, indicating the formation of the PPCS. Ceramic thin film was fabricated onto stainless substrate by dip coating using a 20wt% PPCS in toluene. Heat treatment of the samples was performed at various temperatures (600°C and 800°C) under nitrogen atmospheres. The prepared PPCS samples and the coating layers on SUS316 after heat treatment were analyzed using FT-IR and XPS, respectively.
Influence of Raw Materials on the Preparation of Terracotta Panel
Authors: Zhang Bin , Wang Bao Hua , Shen Liang
Published: August 2011

Influence of the ratio of raw materials on the extrusive property and drying performance of the terracotta panel was investigated by the thermo-gravimetry, differential thermal analysis (TG-DTA) and SEM methods. The results show that the optimization extrusion property of paste body and drying behavior can be achieved by the ratio of plastic and non-plastic materials is 45:55.
Influence of Volume Fraction of Bainite on Mechanical Properties of X80 Pipeline Steel with Excellent Deformability
Authors: Zhang Xiao Yong , Gao Hui Lin , Zhang Xue Qin , Yang Yan
Published: August 2011

The pipeline steel with excellent deformability with ferrite and bainite dual-phase microstructure are obtained by inter-critically accelerating cooling method, aiming to get good deformation capability of avoiding failure from the geological disasters such as landslides and earthquake. The influence of volume fraction of bainite on the mechanical properties of dual-phase pipeline steels was investigated by means of microscopic analysis method and mechanical properties testing. The results indicated that both yield strength and ultimate tensile strength of the steels increase almost linearly with the increasing volume fraction of bainite, while ductility, work hardening exponent and impact absorption energy decrease. When the volume fraction of bainite is about 50%, the yield strength, the yield strength/tensile strength ratio (Y/T), work hardening exponent, uniform elongation and impact absorption energy of X80 pipeline steels with excellent deformability is 665MPa, 0.8, 0.12, 8% and 245J respectively.
Pigment Printing of Natural Dye from Red Mangrove Bark on Silk Fabrics
Authors: Nakpathom Monthon , Somboon Buppha , Narumol Nootsara
Published: August 2011

Recently, the use of natural dyes in textile industry has gained more significant attention owing to environmental concern on the use of certain toxic synthetic dyes. In this research, pigment printing of silk fabrics with natural dye from red mangrove bark has been investigated. Three types of thickening agents, i.e., synthetic thickener, sodium alginate and tex gum were used to prepare printing pastes. In addition, the effects of dye concentration and steaming time during fixation step on color strength in term of K/S values were evaluated. The results on color fastness to washing and light as well as stiffness of the printed fabrics were also reported.
Pollutant Decomposition in Micro Porous Ceramics Made Out of Volcanic Rocks
Authors: Lee Youn Ki , Kim Byung Sung , Ryu Sung Lim
Published: August 2011

Micro porous ceramics made out of volcanic rock have been considered as a pollution control material, since they show unique functional properties such as far infrared ray(IR) radiation, deodorization, anti bacterial function, and hygroscopic function. Here, it is well known that the ceramics have shown a mere adsorption function rather than the decomposition of absorbed substances. In an attempt to endow a sustained deodorization capability into the micro porous ceramics made out of volcanic rock, which has a normal pollution control function, TiO2slurry as a photo catalyst was prepared and spray coated on the surface of the ceramics. Specific heat treatment has been performed at 200°C for 30 minutes after spray coating of TiO2slurry and the subsequent deodorization properties were evaluated using the standard gas-bag method, which was established by Korea Photo catalyst Association and Japan Photo catalyst Association.
Synthesis and Characterization of Triglyceride-Based Copolymer from Soybean Oil
Authors: Saithai Pimchanok , Tanrattanakul Varaporn , Chinpa Watchanida , Kaewtathip Kaewta , Dubreucq Eric
Published: August 2011

The objective of this research is to develop bioplastic from soybean oil. Triglyceride-based copolymers were prepared from free radical copolymerization between acrylated epoxidized soybean oil (AESO) and methyl mathacrylate (MMA). AESO was synthesized by acrylation reaction with acrylic acid. Triethylamine was used as a catalyst and hydroquinone was used as a free radical initiator. The numbers of acrylate groups in soybean oil were determined by using the nuclear magnetic resonance spectroscopy (1H-NMR). Then AESO was copolymerized with MMA as a comonomer to form rigid polymer using 1 wt% of benzoyl peroxide as a free radical initiator. The mixture was cured at 90-100°C for 30 min in the oven. The effect of MMA content between 30-60 pph (part per hundred) based on weight of AESO was also studied. The transparent bioplastic, AESO-PMMA copolymer, are characterized by using the Fourier transform infrared spectrometer (FTIR) to confirm molecular structure. The glass transition temperature was determined by using dynamic mechanical thermal analysis (DMTA). The thermal resistance is analyzed by using thermogravimetric analysis (TGA). The tensile and tear properties were investigated as well.
Preparation of Ca-α-Sialon-SiC Multiphase Ceramics from Gasification Slag
Authors: Yin Hong Feng , Tang Yun
Published: August 2011

The chemical composition, phase constituents and microstructure of gasification slag from Texaco gasifier, the carbothermal reduction nitridation of gasification slag were investigated by X-ray fluorescence spectrometry, X-ray diffractometry and scanning electron microscopy. The effect of nitridation temperature on the phase composition and morphology of nitridation reaction products was studied. Ca-α-sialon—SiC multiphase ceramics were fabricated and characterized. The results showed that: The coal gasification slag was an ideal raw material to synthesize Sialon powder. When introducing 3wt%Y2O3+2wt% MgO into sialon powder carbothermally synthesized at 1450°C, the Vickers hardness and fracture toughness of Sialon-SiC multiphase ceramics hot-pressed at 1650 °C were 18.6 GPa and 5.2 MPa·m1/2, respectively.
Graft Copolymerization of Soybean Protein Isolate and Methyl Methacrylate
Authors: Lu Yan , Luo Xue Gang , Lin Xiao Yan
Published: August 2011

New thermoplastic soy protein isolated (SPI) and methyl methacrylate (MMA) copolymers (T-SPI) were prepared using graft copolymerization and initiated with ammonium persulfate (APS). The reaction conditions such as initiator concentration and temperature on the graft percentage (GP) were investigated. The single factor experimental showed that the optimal conditions of the graft reaction. The products were characterized by means of FT-IR and DSC. The results indicated that the monomer was grafted successfully on SPI and the T-SPI had a glass transition at 122°C, and the most important, the water absorption of materials declined obviously.
Rubber Blend of 80/20 NR/SBR Reinforced with Nanosilica and PS-Encapsulated Nanosilica
Authors: Boonmahitthisud Anyaporn , Song Zheng Hua
Published: August 2011

In this study, rubber blend of natural rubber (NR) and styrene butadiene rubber (SBR) at 80/20 NR/SBR was reinforced with nanosilica (nSiO2) and polystyrene-encapsulated nanosilica (PS-nSiO2) in the latex state. The latex of PS-nSiO2 was synthesized by in situ differential microemulsion polymerization using sodium dodecyl sulfate and azobisisobutyronitrile as the surfactant and initiator, respectively. The nanoparticles at the amount of 0.1, 0.2, 0.3 and 0.4 parts per hundred of rubber (based on dry weight of nSiO2) were dispersed in the rubber blend compound and subsequently cured at 80°C for 3 h to prepare rubber nanocomposites. Using this technique, nanoparticles could be well dispersed in the rubber matrix. The influences of the nSiO2 and PS-nSiO2 on the mechanical and thermal properties of the resulting nanocomposites were quantified and compared. It is found that the tensile properties and thermal stability of the rubber blends were improved with the appropriate amounts of the nanofillers. However, the PS-nSiO2 exhibited reinforcing efficiency superior to nSiO2 with the same nSiO2 content due to the stronger rubber-filler interfacial adhesion.
Electrochemical Synthesis of Sensitive Layer of Polyaniline/Multi Wall Carbon Nanotube Composite
Authors: Pattananuwat Prasit , Aht-Ong Duangdao
Published: August 2011

The release of ethylene gas from agricultural products such as fruits, vegetables, and flowers during storage and transportation is the main cause of blooming of flowers and ripeness of fruits before their ripening phase. The ethylene gas acts as hormone plant leading to a decrease in the life time of agricultural products and a deterioration of product value. The continuous development of ethylene gas sensor is needed to increase an efficiency in detection and indicating life time cycle of agricultural products. The aims of this research were to fabricate ethylene gas sensor based on polyaniline/multiwall carbon nanotube (PANi/MWCNT) composites and to investigate the effect of MWCNT content on an improvement of its sensitivity. The sensitive layer for ethylene sensor was electrochemically synthesized from aniline in acid aqueous solution with different amounts of MWCNT. With cyclic voltammetry method, the sensitive layer of PANi/MWCNT was electrochemically synthesized via an in situ radical polymerization by repeating potential cycling in the range of -0.3 to 1.0 V relative to the silver reference electrode and platinum counter electrode. The response of these composite films for ethylene gas was evaluated by monitoring the change in electrical resistance at room temperature. After three month aging, the results revealed that the PANi/MWCNT composite films had higher response than pure PANi film and can be responded ethylene gas as lower as 10 ppm. The PANi/MWCNT composite films were characterized by fourier transform raman spectroscopy (FT-RAMAN). Thermal behaviors of PANi-MWCNT composite films were investigated by thermogravimetric analyzer (TGA). The morphology of PANi/MWCNT composite films were investigated by scanning electron microscope (SEM).
Research on the Optimization of Ni/Si Atomic Ratio for Cu-Ni-Si Alloys with High Strength and High Electrical Conductivity
Authors: Jia Lei , Xie Hui , Lu Zhen Lin , Wang Xiao , Zhao Ya Ling
Published: August 2011

Two sets of Cu-Ni-Si alloys with different Cu contents and Ni/Si atomic ratios were fabricated under the state of near-equilibrium solidification. The microstructures were observed by SEM and phase compositions were identified by XRD. The electrical conductivity and hardness were tested by Eddy-Conductivity Apparatus (ECA) and Digital Rockwell Hardmeter, respectively. The experimental results show that all the researched Cu-Ni-Si alloys are consisted of three phases, i.e. α-Cu(Ni,Si), Ni3Si and δ-Ni2Si. With the increase of Ni/Si atomic ratio, the amount of Ni3Si decreases persistently but that of δ-Ni2Si and electrical conductivity increases firstly and then decreases, the hardness decreases firstly and then increases following by a decrease finally. Both the electrical conductivity and hardness reach a relativity highest value when the Ni/Si atomic ratios are 2.6:1 and 2.4:1 for Cu-Ni-Si alloys with 95wt.% and 90wt.% Cu content respectively.
Artificial Neural Network to Predict the Hot Deformation Behavior of Super 13Cr Martensitic Stainless Steel
Authors: Han Ying , Qiao Guan Jun , Yan Dong Na , Zou De Ning
Published: August 2011

The hot deformation behavior of super 13Cr martensitic stainless steel was investigated using artificial neural network (ANN). Hot compression tests were carried out at the temperature range of 950°C to 1200°C and strain rate range of 0.1–50s–1at an interval of an order of magnitude. Based on the limited experimental data, the ANN model for the constitutive relationship existed between flow stress and strain, strain rate and deformation temperature was developed by back-propagation (BP) neural network method. A three layer structured network with one hidden layer and ten hidden neurons was trained and the normalization method was employed in training for avoiding over fitting. Modeling results show that the developed ANN model can efficiently predict the flow stress of the steel and reflect the hot deformation behavior in the whole deforming process.
Nano Composite Membranes of Sulfonated Poly(ether sulfone) Containing 4,4-Bis(4-hydroxylphenyl)valeric Acid and SiO2 for PEMFC
Authors: Lim Young Don , Seo Dong Wan , Lee Soon Ho , Islam Md. Monirul , Jin Hyun Mi , Jang Ho Hyoun , Jeong Insuk , Kim Whan Gi
Published: August 2011

Poly(ether sulfone)s (PES) containing 25-75 mol % valeric acid were prepared with bisphenol A, bis(4-chlorophenyl)sulfone and 4,4-Bis(4-hydroxylphenyl)valeric acid using potassium carbonate in DMAc (dimethylacetamide) at 160 °C. Copolymers containing carboxylacid group were reduced to hydroxy group by BH3solution 1M in THF and NaBH4 co-catalyst. Sulfonated poly(ether sulfone)s (S-PES) were obtained by reaction of 1,3-propanesultone and the reduced copolymer (PES-OH) with potassium t-butoxide. 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 were studied by1H-NMR spectroscopy, differential scanning calorimetry (DSC), and thermo gravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol.
Investigation of Fabrication and Microstructure of the Fe3Al/Al2O3 Composites by Hot-Pressing Process
Authors: Jiang Tao , Jin Hai Yun
Published: August 2011

The Fe3Al/Al2O3composites were fabricated by hot-pressing process at 1300°C for 2h under the pressure of 35MPa, by using the Fe3Al intermetallics compounds powders fabricated by mechanical alloying and heat treatment. The phase composition and microstructure of the Fe3Al intermetallics compounds powders and Fe3Al/Al2O3composites were investigated. The XRD patterns results showed that the Fe-Al intermetallics compounds powders were prepared by mechanical alloying for 60h and heat treatment process at 800°C and 1000°C. The XRD patterns results showed that there existed Fe3Al phase and Al2O3phase in sintered composites. The Fe3Al/Al2O3composites exhibited homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in Al2O3matrix. The mean particles size of Fe3Al was about 3-4μm and the mean particles size of Al2O3matrix was about 4-5μm.
Effect of Ag Addition on the Microstructure and Mechanical Properties of High Conductivity Cu-1Cr-Mg-P Alloy
Authors: Lee Seung Jin , Park Joon Sik , Kim Ki Tae , Kim Jeong Min
Published: August 2011

High strength high conductivity Cu-1%Cr-Mg-P alloy was selected as a base composition and Ag was added to the alloy in order to further increase the strength without sacrificing the conductivity. SEM and TEM analyses indicated that very fine MgP and Ag(Mg) precipitates were formed in addition to relatively large Cr phase in the Cu matrix. Significantly high strength could be obtained through the special cold rolling at an extremely low temperature using liquid nitrogen. The electrical conductivity of alloy was slightly decreased by the Ag addition, but the tensile strength could be further enhanced by it.
Using GA–ANN to Optimize Heat Treatment Technological Parameters of Super-Martensitic Stainless Steel
Authors: Liu Huan , Yu Jun Hui , Wang Duo , Zou De Ning
Published: August 2011

In this investigation a theoretical model based on artificial neural network (ANN) and genetic algorithm (GA) have been developed to optimize the heat treatment technological parameters for achieving the excellent mechanical property of super-martensitic stainless steel (SMSS). The ANN was used to correlate the heat treatment technological conditions to the mechanical property. The GA and ANN were incorporated to find the optimal technological parameters. The result shows that the most optimal heat treatment technological is 1003.9°C×0.5h (air cooling) +629.75°C+2.06h (air cooling). By comparing the prediction values with the experimental data it is demonstrated that the combined GA–ANN algorithm is efficient and strong method to find the optimum heat treatment technological for producing super-martensitic stainless steel.
Effect of Heat Treatment on the Microstructural Characteristics of IN738 Turbine Blade
Authors: Yun Ho Seob , Park Joon Sik , An Seong Uk , Kim Jeong Min
Published: August 2011

It was observed that both primary and secondary gamma prime precipitates were more significantly influenced by the solid solution treatment temperature as compared to the following cooling rate. Single and duplex size precipitate distribution with different average size could be obtained through the appropriate solid solution and aging treatment. Micro-hardness test result indicated that single size distribution of gamma prime precipitates provides higher hardness than duplex size distribution.
Separability of Fe from Cyanide Tailing by Magnetic Roasting
Authors: Zhang Zhao Hui , Liu Bai Long , Ma Hong Zhou , Wei Wu Qiang
Published: August 2011

According to the properties of cyanide tailing from Lingbao, the quantitative analysis and phase analysis were chosen to define the chemical composition of the tailing and separability of Fe from cyanide tailing was investigated. The impacts of parameters on the recovery of Fe were probed to determine the optimal iron separation technological flow. The result indicated that the iron ore concentrate containing 62.69% Fe can been obtained by wet and weak magnetic separation (one roughing and two cleaning) under the optimum conditions of stirring intensity 1800r/min, stirring time 15min, roughing magnetic field intensity 63.68KA/m, and cleaning magnetic field intensity of Ⅰand Ⅱ47.76 and 39.80 KA/m separately, and a recovery ratio reached 81.78%.
Synthesis of High-Purity Ti3SiC2 by Infiltration-Sintering
Authors: Lu Zhen Lin , Xiao Qi Dan , Zhou Yong Xin , Xie Hui
Published: August 2011

Titanium silicon carbide (Ti3SiC2) is a remarkable material for its combination of the best properties of metals and ceramics. The high purity Ti3SiC2 ceramic has been prepared by infiltration sintering (IS), and the effect of a small amount of Si on Ti3SiC2 ceramic formation was investigated. The results show that the purity of Ti3SiC2 ceramic could be increased significantly and the sintering time for Ti3SiC2 could be decreased remarkably when proper amount of Si was added in the starting mixture. The Ti3SiC2 sintered compact with a purity of 99.2wt% and a relative density of 97% was obtained by the infiltration sintering from a starting mixture composed of n(Ti):n(Si):n(TiC) = 1:0.3:2 at 1500 °C with holding time of 2/3h.
Investigation of Thermal Sprayed Stainless Steel/WC-12wt%Co Nanocomposite Coatings
Authors: Banjongprasert Chaiyasit , Jaimeewong Piyaporn , Jiansirisomboon Sukanda
Published: August 2011

The thermal spray coatings of stainless steel with nano-sized particles as reinforcement have been studied. Stainless steel powder mixed with 0, 2.5, 5 and 10 wt% WC-12wt%Co nano-sized powder was flame sprayed. The presence of WC-12wt%Co nano-particles in mixed powders as feedstock was confirmed. The microstructure of the coatings has been investigated using a wide range of characterization techniques: optical microscopy with image analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) to understand the microstructure evolution. Chemical composition and microstructure of the coatings showed that the coatings contained stainless steel, WC, Co, and oxide layers. The addition of WC-12wt%Co increased cross-sectional hardness, reduced porosity and friction coefficient. The improved wear properties demonstrate a high potential for industrial applications of stainless steel/WC-12wt%Co coatings.
Ultrasound-Enhanced Electrochemical Preparation of Atomic Oxidants
Authors: Li Lin Bo , Xue Juan Qin , Hong Tao , Yang Jun , Zhang Yi
Published: August 2011

The atomic oxidant was prepared under conditions of ultrasound and non-ultrasound. The influence of electrolysis time, electrolyte concentration, electrolysis voltage and additive concentration on concentration of oxidant were investigated. The results show that ultrasound could enhance the perpetrating rate. For ultrasonic cavitation and chemical effect, the concentration of oxidant significantly increased. Under the condition of electrolysis time 3 hours, voltage 6V, 35% sulfuric acid concentration and 0.5g/L additive, the ultrasonic frequency 40kHz and power 150W, the effect of oxidation could get the best result, and the oxidant concentration reached 0.9177mol/L.
Surface and Mechanical Properties of Cellulose Micro-Fiber Reinforced Recycle Polyethylene Film
Authors: Aht-Ong Duangdao , Atong Duangduen , Pechyen Chiravoot
Published: August 2011

This work involved a study of polymer-fiber composites as biodegradable packaging made from recycled polyethylene (r-PE) and chemical-treated cotton fabric waste micro fibers. A compatibilizer, polyethylene-graft-maleic anhydride (PE-g-MA), was used to improve properties of the composites. Factors affecting composite properties were investigated including % PE-g-MA loading, and % fiber loading. The fiber composites were prepared by melt-blending technique. The materials were first mixed by a twin-screw extruder and shaped into samples by an extrusion blow molding machine. The samples were then characterized for mechanical, and morphological properties. It was found that properties of the composites were improved by adding the compatibilizer. Optimum properties of the composites were found at 10% (wt%) PE-g-MA loading. It was also revealed that tensile strength and modulus was found to increase as the % fiber loading was increased. SEM micrographs confirmed that interfacial bonding between the cellulose fibers and the r-PE matrix was enhanced as fewer voids at the interfaces were revealed by adding the PE-g-MA compatibilizer to the composites. Film formation occurred on all composites even if the polymer itself was inert biodegradation. The microbial colonization affected mainly of surface properties r-PE composites while changes were monitored also in the bulk properties of cellulose microfiber.
Doted Titania(B) Nanobelts with Anatase Nanocrystals for Improved Photocatlytic Activity
Authors: Luo Jian Qiang , Gao Lian , Sun Jing
Published: August 2011

Titania(B) nanobelt and anatase titania nanobelt could be prepared by calcining hydrogen titanate nanobelt at 450 °C and 550 °C respectively. When the hydrogen titanate was previously treated with HNO3 for some time before calcination at 450 °C, titania(B) and anatase mixed phase titania could be obtained. The ratio of anatase phase in the product could be changed by control the time of HNO3 treating. TEM images show that the mixed phase product was anatase nanocrystals doted on titania(B) nanobelts. The mixed phase product shows higher photocatalytic activity on the decomposition of Methylene Blue (MB) than the pure titania(B) nanobelt and anatase nanobelt.
Preparation of Nanocrystalline W-Doped TiO2 Powders and their Photocatalytic Properties under Visible Light Irradiation
Authors: Song Yun Ting , Shao Wei Na , Cao Wen Bin
Published: August 2011

Nanocrystalline W-doped TiO2 powders with different initial W/Ti ratio in starting materials have been prepared by hydrothermal method. The phase composition, morphologies, specific surface areas and the photocatalytic activities under visible light irradiation of the synthesized powders have been characterized. XRD identification reveals that the synthesized powders were composed of anatase. No rutile has been detected in the products. The specific surface area of the powders was ranged from 185 to 210 m2/g by BET measurement. The averaged grain size of the powders was calculated as about 12 nm by Scheller's method. Uniform size distribution and good crystallinity have been confirmed by TEM. UV-Vis spectra show that the absorption edges of the synthesized W-doped TiO2 powders with different nominal doping concentration of Wions have been red-shifted into visible light region, which suggests that the W ions have been doped into the lattice of TiO2. In our case, W-doped TiO2 with initial W/Ti atomic ratio of 1% in starting materials has the best photocatalytic activities when decompose the Methylblue in its aqueous solution, which is consistent with that of the theoretical results from our previous work.
Fabrication of Bi0.5Na0.5ZrO3 Powder by Mixed Oxide Method
Authors: Jaiban Panupong , Rachakom Ampika , Buntham Suwapitcha , Jiansirisomboon Sukanda , Watcharapasorn Anucha
Published: August 2011

Lead-free bismuth sodium zirconate powder with formula Na0.5Bi0.5ZrO3 was prepared by conventional mixed oxide method. Bismuth sodium zirconate (BNZ) powder with 10wt%Na2CO3 was calcined at 800 °C for 2 h dwell time. Investigation of the effects of re-calcination and dwell time on phase formation of powders was also carried out. The results revealed that re-calcination significantly affected the formation of single-phase BNZ powder. Phase characteristics were checked by X-ray diffraction (XRD). Powder Cell software was employed to simulate crystal structure of BNZ powder. It was found that BNZ powder most likely possessed an orthorhombic structure. SEM result showed its average particle size was 0.47 mm and composition measured EDX correlated with theoretical composition of BNZ.
Pyrolysis Characteristics and Kinetics of Low Rank Coal
Authors: Song Yong Hui , She Jian Mei , Lan Xin Zhe , Zhou Jun
Published: August 2011

The pyrolysis characteristics of Jianfanggou(JFG) coal was studied using a thermo-gravimetric analyzer and the pyrolysis kinetic parameters were calculated at the different heating rate. The results showed the DTG curves under different heating rate had three peaks and the corresponding temperature were 100°C, 470°C and 750°C, the pyrolysis process can be divided into three stages conclusively. The maximum weight loss rate at 470°C indicated the major weight loss occurred in the second stage. The Tb, Tf and T∞ obtained under experiment situation. The results of the JFG coal pyrolysis kinetic showed the Tb, Tf and T∞ increased gradually with the accretion of the heating rate. In the meantime, the variation of frequency factor was consistent with the trend of activation energy.