bluuebunny/crossref_metadata_2025 huggingface dataset:
Research of BOF Protection Technology by Slag Splashing
Authors: Guo Hong Min , Yang Jun
Published: August 2009

Based on the application of slag splashing for building up a protective coating layer on the refractory lining, a technique for comprehensive maintenance of converter refractory linings has been developed in this paper. The effect of slag properties, slag amount, tapping temperature, and lance height on the splashing was investigated by physical model experiments. The facilities and regimes of 50-ton converter at the Long-steel had been modified. At present, the life of converter lining has already reached to 15,000 heats, the productivity reached 87 %.
Environmentally Benign Material Removal Processes for the Fabrication of Microdevices
Authors: Danyluk Steven , Blackburn Travis , Butler David , Seng Leo Cheng
Published: August 2009

Non-contact material removal processes offer numerous advantages over traditional machining approaches and nowhere is this more apparent than in the fabrication of micro devices. Current micromachining techniques such as microgrinding and micromilling have limitations with respect to their positioning accuracy and tool deflections. Electro thermal processes such as microEDM and laser machining usually result in a heat affected zone being produced. Other approaches such as etching and non-contact ultraprecision polishing are either costly or are not suitable for high throughput. In order to address these limitations, alternative micromachining techniques are required.

In this paper, a non-contact material removal technique based on the electrokinetic phenomenon is proposed for precise material removal at rates in the order of nanometers/min. The aim of this research is to have a better understanding on the electrokinetic material removal technique by studying the trajectory of the particles and the influence of the frequency of the electric field on the material removal rate.
Preparation of Ti/Cu Oxide Coating on Alumina by Sol-Gel Method
Authors: Sang Ke Zheng , Liu Lin , Zeng De Jun , Fan Zhang Zeng
Published: August 2009

Using TiCl4 and CuCl2 as precursors, the sols were prepared. The coatings of Ti/Cu oxide were formed on both glass and alumina substrates by dip-coating method. XRD results showed that the coatings could be composed of anatase TiO2, CuO and M6O type oxides. The M6O type oxide on glass substrate is in the form of Cu3Ti3O, however is Cu2Ti4O on alumina substrate. The formations of the CuO and M6O are related to the Cu:Ti ratio. A high Cu:Ti ratio corresponds to the CuO, whereas to the M6O. Also the sols were analyzed by infrared spectroscopy and the mechanism of the formation of the coatings was discussed in the paper.
Preparation of Nano-Sized ZnO Powder by Freeze-Drying
Authors: Jeong Jeong Hwan , Lim Hyung Mi , Kim Dae Sung , Paik Ung Yu , Lee Seung Ho
Published: August 2009

Zinc oxide(ZnO) has been widely applied in the fields of cosmetics, paint, coating and gas sensor. Size down of ZnO is essential for the preparation of sol or film of ZnO in the application. The size and shape of ZnO particles are controlled by varying drying method. The ZnO was prepared by mixing of zinc acetate and sodium hydroxide at 0°C. Then it was freeze dried or 20°C vacuum dried. After washing the residual ions, it was further compared by drying at 20°C vacuum drying or 200 °C oven drying. The ZnO powder was characterized by XRD, Brunauer-Emmet-Teller analysis(BET) and transmission electron microscope(TEM). The ZnO have wurzite structure with ~10 nm particle size when it was prepared by freeze drying and then 20°C vacuum drying after washing the residual ions. On the other hand, without freeze drying, the ZnO particles observed to be aggregated to 200~400 nm with primary particle size of ~20 nm. The smaller size of ZnO particle in freezing drying compared to 20°C vacuum drying may be explained by frozen water preventing the growth of ZnO particles.
Preparation and Properties of PP/PLA /Multiwall Carbon Nanotube Composites Filaments Obtained by Melt Compounding
Authors: Zou Jing , Zhang Ying Chen , Huang J.N. , Wu Hong Yan , Qiu Y.P.
Published: August 2009

The present paper studied the thermal and mechanical properties of atmospheric pressure plasma jet (APPJ) treated multiwall carbon nanotubes/polypropylene/polylactic acid nanocomposite filaments. The experiments included tensile tests, differential scanning calorimeter (DSC), Scanning electron microscopy (SEM) experiments. DSC studies showed that there were a distinct shift in Tg and a relatively moderate change in Tm for different systems. The activation volumes of CNTs/PP/PLA nanocomposite filaments have been calculated to describe strain rate sensitive behavior of CNTs/PP/PLA nanocomposite filaments by following Eyring’s equation based on the tensile test results.
Growth of Highly Orientated and Well-Aligned ZnO Nanowhiskers Using Aqueous Solutions
Authors: Hu Xiu Lan , Masuda Yoshitake , Ohji Tatsuki , Kato Kazumi
Published: August 2009

Length-tailored, monodisperse, highly orientated, single-crystalline hexagonal and aligned ZnO nanowhiskers were grown onto F-doped SnO2 conductive glass (FTO) substrate at 88 °C using an aqueous solution. The aqueous solution for growth of ZnO nanowhiskers included zinc nitrate hexahydrate, hexamethylenetetramine and polyethylenimine. The addition of branched polyethylenimine, which may be adsorbed on the nonpolar surface of ZnO crystals, improved the growth of ZnO nanowhiskers along the c-axis.
The Strain Rate Sensitivity of Plasma Treated Nano TiOx Particles/PP/PLA Nano-Composites Filaments
Authors: Huang Jing Nan , Zhang Ying Chen , Zhu Hai Yan , Wu Hong Yan , Qiu Y.P.
Published: August 2009

In the current study the role of plasma treated nano titanium dioxide particles and strain rate on the tensile properties of plasma treated nano TiO2 particles/PP/PLA nano-composites filaments (PTNTOPPCF) was studied. The experiments included tensile tests and differential scanning calorimetry (DSC). The addition of the plasma treated nano titanium dioxide particles into PP/PLA caused a change in Young's modulus and yield stress of the composites. Strain rate sensitivity of the PTNTOPPCF changed as plasma with and without oxygen treated nano titanium dioxide particles was added to it with different percentage of weight. It was increased with more PLA, MAH, and higher flow rate of oxygen. Activation volumes ranged in 4−40(nm)3 for true nanocrystalline material estimated by the Eyring equation, which were changed un-monotonically with oxygen plasma treatment.
Crystallization and Mechanical Properties of Nano ZnO/PP/PLA Composite Filaments
Authors: Zhang Ying Chen , Xie Jian Fei , Wu Hong Yan , Qiu Y.P.
Published: August 2009

In the present work, the effect of plasma treated ZnO nanoparticle on crystallization behavior and properties of polypropylene（PP）/ polylactic acid （PLA）composites filaments has been intensively researched. Our results show that, although the interfacial interaction between PP/PLA and nano ZnO is very weak, addition of nano ZnO and the proportional relations of PP/PLA in composites induced the increase of percent crystallinity. Tensile results showed that nano ZnO /PP/PLA nanocomposites filaments were strain rate sensitive materials and the activation volumes of the nano ZnO /PP/PLA nanocomposite filaments by following Eyring’s equation could be evaluated.
Preparation of Sb:F:SnO2 Films and their Application in Low-E Glass
Authors: Zhao Gao Yang , Zhi Xiao , Ren Yang , Zhu Tao
Published: August 2009

In this paper, fluorine & antimony-doped tin oxide (FATO) transparent conductive thin films are deposited by Spray Pyrolysis on glass substrate, and low emissivity properties achieved. The emissivity of glass in far infrared region is optimized by changing the spray volume, the resistivity and sheet resistance of thin films. Research shows that the resistivity of thin films has important influence on infrared reflectance and hemispheric emissivity. This paper further investigates the quantitative relationship between emissivity and resistivity of low-E glass and also provides a basis for emissivity control and performance evaluation of Low-E glass.
Effect of Nano-Sized Metal Colloids on Color Change of Photosensitive Glass by Using X-Ray Irradiation
Authors: Park Yong Kap , Cho In Churl , Choi Y.
Published: August 2009

X-ray irradiation was applied to control the size of metal colloids in a silicate glass to make a high precise photosensitive glass containing K2O, Na2O, ZnO BaO, 0.01-0.05wt.% Au metal as sensitizer, <1.2wt.% Sb2O3 and SnO2 as thermal reducer. Colorimetry showed that X-ray irradiation effectively works to make the color of red system. Transmission electron microscopy revealed that the metal colloids were oxided and had uniform and spherical shape of 10-20 nm. Au colloid made various colors like pink after heating at 400°C, red at 500°C and dark-red at 600°C. Ag colloid made them like yellow-green at 400°C, yellow at 500°C and dark-brown, respectively.
Preparation and Electrocatalytic Properties of Single Walled Carbon Nanotube/Platinum Nanoparticle Composite
Authors: Zhang Jing , Gao Lian , Sun Jing , Wang Yan
Published: August 2009

The SWNT/Pt composite with high electrocatalytic property was successfully fabricated through pretreating SWNTs by acid and NH3 treatment. According to the hydrodynamic voltammograms and the current response for H2O2, the SWNT/Pt composite was demonstrated to have faster and more sensitive response than SWNTs, indicating the enhanced electrocatalytic property of SWNT/Pt composite.
Fabrication Process for Nanorod Array Structure by Using Aluminization and Internal Oxidation of Nickel
Authors: Do Dung Thi Mai , Uemura Katsumi , Nanko Makoto
Published: August 2009

An aluminization process with controlled Al activity to form surface Ni(Al) zone was applied to fabricate ceramic nanorod array structures by using internal oxidation. The pack cementation with NaCl, Ni3Al and Al2O3 was adapted as the aluminization process to form surface Ni(Al) zone. With increasing Ni3Al concentration in pack powder mixture, Al content of surface Ni(Al) zone was increased. Nanorod array structures can be successfully obtained on Ni components with designed shape.
Preparation and Microstructural Characterization of Al2O3/ZrO2 Nanocomposites to Use in the Femoral Head of Hip Replacement
Authors: Zhou Gang , Lee Soo Wohn , Li Yu Bao
Published: August 2009

High-purity aluminum oxide is potentially an attractive implante material for total hip joint replacement, because its biocompatibility, excellent wear resistance, high strength and corrosion resistance. The main problem of alumina is relatively low fracture toughness. Thus, this study is the introduction of ZrO2 as second ceramic phase homogeneously dispersed wihtin an alumina matix. Al2O3/ZrO2 nanocomposites disk is prepared by spark plasma sintering (SPS) method at 1500°C and 50MPa, in vacuum for 5min. Then, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the microstucture and phases of this nanocomposite. Moreover, frexual sthrength of the nanocomposites was meausured as well as hardness and fracture toughness. When the content of ZrO2 is up to 15wt%, the fracture toughness value (8.4MPam1/2), and strength (527MPa) are achieved. This Al2O3/ZrO2 nanocomposites may be served as a tatal hip joint replacement.
Preparation of Silver Nanoplates in SDBS System
Authors: Song Yong Hui , Yang Yong , Gao Wen Wen , Lan Xin Zhe
Published: August 2009

Silver nanoplates were prepared in the solution of sodium dodecyl benzene sulfonate (SDBS) and polyvinyl pyrrolidone (PVP) via reducing silver nitrate with hydrazine hydrate. X-ray diffraction (XRD) and Scanning electron microscope (SEM) were applied to identify phase and observe microstructure. The surface tension analysis showed that in SDBS + PVP system, the γ-C curve acted as dual-platform and the corresponding concentration turning points were C1 (0.8g/L) and C2 (6.0g/L) respectively. XRD analysis confirmed that the reduction product was element silver. SEM observation revealed that nano-plates silver were obtained when the SDBS concentration was between C1 and C2, otherwise spherical-shaped nanoparticles were synthesized.
Effect of Surface Nanocrystallization Method on Fatigue Strength of TA2
Authors: Wen Ai Ling , Ren Rui Ming , Wang Sheng Wu , Yang Jun Yong
Published: August 2009

The enhancement of the fatigue strength is significant for the engineering applications of commercial pure titanium and its alloys. The paper investigated improvement of fatigue strength for commercial pure titanium by combined high-energy shot peening. Firstly, nano-crystallization in surface layer of pure titanium was carried out by high-energy shot peening, and then the shot peening with small diameter shots was introduced to degrade the surface roughness, enhancing the quality of the nano-grained surface. The fatigue limit of pure titanium by high-energy shot peening turns out to be increased by 34%, and the fatigue limit of pure titanium by compound high-energy shot peening turns out to be increased by 52.3%, according to the results. Effective factors such as surface states etc. to fatigue life, the fatigue crack initiation and propagation behaviors were also discussed in this paper.
Fabrication of Nano-MgO Reinforced Fe-Cr-Ni Composites by Reactive Hot Pressing
Authors: Chen Chang , Yang Jian Feng , Gao Ji Qiang , Chu Cong Yang
Published: August 2009

The self-propagating combustion reaction 0.741Mg + 0.247Fe2O3 + 0.188Ni + 0.318Cr → 0.741MgO + Fe0.494Ni0.188Cr0.318 was applied to prepare a nano-MgO reinforced Fe-Cr-Ni composite, by reactive hot pressing (RHP) under a condition of 700°C/30MPa/2h. The densification was enabled by the low temperatures produced by the exothermic reaction. According to TG-DTA and X-ray diffractometry (XRD), the highly-exothermic thermite reaction began at about 600°C and the in-situ formation of composites comprised predominantly of (FCC) Cr0.19Fe0.7Ni0.11, (FCC) Fe-Cr, (BCC) MgO and a small quantity of (BCC) MgFe2O4. The Vickers hardness was 3.67GPa, the three-point bending strength was 112.5±10MPa, and the fracture toughness was 3.28 MPa•m1/2. The microstructure of the composite was observed via scanning electron microscopy. This indicated that the distributions of in-situ-formed (BCC) MgO phases (~800 nanometers) were homogeneous into in a matrix of a fine-grained metallic alloy phases that gather together to form agglomerates in the composite.
Adsorption and Deposition of Cu (II) on Modified Valonia Tannin
Authors: Li Yi , Luo Xue Gang , Liu Zhao , Huang Yan , Long Xiao Yan
Published: August 2009

The modified valonian tannin was prepared through sulfonated-mannich reaction and used to adsorb Cu (II) from the aqueous solutions. The adsorption capacity rapidly reached equilibrium within 2 hours. The effect of pH on adsorption was apparent, the amount of adsorption increased significantly as the pH increased from 2.0 to 4.0 and then leveled off at pH 4.0-6.0. Equilibrium data fitted well with Freundlich isotherm model compared to Langmuir isotherm model, indicating that adsorption takes place on heterogeneous surface of the modified valonia tannin. The adsorption capacity was increased by increasing initial concentrations. The maximum adsorption capacity of cooper ion was determined to be 56.200 mg/g at 100 mg/L concentration.
Applied Study of Fibre Padding and Ceramic in Micro-Polluted Water Treatment
Authors: Zhang Xiao Dong , Chen Ji Hua , Xi Dan Li
Published: August 2009

The ecological fiber is a new water treatment material that is processed by simulating the shape of wild water-borne plant. In recent years it has been applied broadly in sewerage treatment for its following advantages: big specific surface area, high capacity in removing organic matter, good microbiological adhesiveness, variable pore sizes, wonderful performance in preventing jamming, flexibility in operation and management, etc. Ceramic padding has high porosity and moderate density which is highly favorable to the growth of microorganisms. This paper discussed treating the micro-polluted water by the combination of oxidation pond and constructed wetland. The results show that some indexes of the treated water reached or exceeded band 3 national water quality standards. These indexes include TN (total nitrogen), TP (total phosphorus), TDP (total dissolved phosphorus), CODCr and so on. The research results can provide scientific basis for project design.
In Vitro Cytocompatibility of Plasma-Sprayed Dicalcium Silicate/Zirconia Composite Coating
Authors: Xie You Tao , Zheng Xue Bin , Ding Chuan Xian , Liu Xuan Yong , Zeng Yi , Lee Soo Wohn
Published: August 2009

The in vitro attachment, spread, and proliferation behavior of osteoblast cells on the plasma-sprayed composite coating with 70wt% zirconia and 30wt% dicalcium silicate were studied. The composite coating shows good cytocompatibility. The human osteoblast cells attached, spread and proliferate well on the surface. The cytocompatibility of the coating was attributed to the incongruent dissolution of dicalcium silicate and the large amount of Si-OH functional groups produced on the surface. The released calcium and silicon ions are also positive to the proliferation of cells. All our results show that the composite coating possesses good cytocompatibility.
Effects of Atomizing Gas on Microstructural Characteristics and Mechanical Properties of Spray Formed High Si Steels
Authors: Shin Je Sik , Kim Bong Hwan , Lee J.G. , Shin Seung Y. , Choi Gwang Bo , Moon B.M.
Published: August 2009

In order to investigate the feasibility of spray forming process for production of high Si steel sheets, 4.8~6.4%Si steels were prepared by spray forming process using N2 and Ar gases and their cold workability was compared with that of conventional ingot cast samples. Atomizing gas affected significant effect on deposit features, microstructural characteristics and mechanical properties of the spray formed high Si steels.
Extraction of Lignin from Pulping Black Liquor by Organic Acid
Authors: Liu Zhao , Luo Xue Gang , Li Yi , Li Ling , Huang Yan
Published: August 2009

The lignin was extracted and purified by organic acid from pulping black liquor, and the process and influencing factors of extraction and purification were studied. The results of single factor experiments showed that the citric acid which contains three -COOH was suitable to extract and purify lignin. The results of orthogonal experiment demonstrated that the optimal condition of extraction and purification was as follows: citric acid saturated solution, 80°C, pH value of acid evolution endpoint was 3.0. The analysis of FT-IR spectrum, GPC and DSC indicated that the type of lignin extracted by citric acid was G-S, and the lignin was characterized as complete structure, higher molecular weight and Tg. The study on extraction technology of high purity lignin by citric acid method is hopeful to overcome the disadvantages of exorbitant cost and secondary pollution caused by the residues from lignin separation. It could change waste into valuables and put resource utilization of pulping black liquor into practice.
Response of MG63 Osteoblast-Like Cells on Pyrolytic Carbon Coated Carbon/Carbon Composites
Authors: Li He Jun , Zhang Lei Lei , Li Ke Zhi , He Yong Gang , Zhao Xue Ni , Zhao Hua
Published: August 2009

In order to improve the biocompatibility of carbon/carbon(C/C) composites used for hip prosthesis, pyrolytic carbon coating was prepared on their surface by chemical vapor deposition. The microstructures of the samples were analyzed by scanning electron microscopy (SEM) and the biomedical response was assessed by the morphology and proliferation of MG63 osteoblast-like cells. The results show that the texture on the surface of C/C composites changes from chaotic structure to uniform state after the pyrolytic carbon coating is prepared. Osteoblasts cultured on pyrolytic carbon coating present flat shape with thin thickness, and display better proliferation in comparison with those on the uncoated C/C composites surface.
Corelation of Colorimetric Parameters with Collapse-Shrinkage Properties in Plantation-Grown Eucalyptus Based on Eco-Furniture Materials
Authors: Wu Yi Qiang , Kazuo Hayashi , Cai Ying Chun
Published: August 2009

In order to quantify the relationship between collapse-shrinkage properties and colorimetric parameters on plantation-grown eucalyptus as solid-wood furniture, measurements of the above-mentioned indices were carried out on five species of plantation-grown Eucalyptus (Eucalyptus urophylla, E.grandis, E.urophylla×grandis, E.grandis ×urophylla and E.cloeziana) under three kinds of heat-treat patterns(heat, steaming and combination of heat and steaming) and their correlations were investigated by means of regression analysis. Results showed that for the former four low-density prone-collapse eucalypt, collapse-shrinkage properties were strongly correlated with L* and △E*( R2 ≥0.85) under the above treated conditions, while weak linear correlation with a* and b*. For high-density E.cloeziana with extremely lower collapse, the four colorimetric indexes were lightly correlated with collapse-shrinkage properties. Thus, it can be concluded that L* and △Eab* may be regarded as the two primary and more reliable predictors of shrinkage-collapse parameters for low-density collapse-prone eucalypt wood.
Study of Nano-Hydroxyapatite/Polycarbonate Composite for Bone Repair
Authors: Liao Jian Guo , Li Yu Bao , Zhang Li , Zuo Yi
Published: August 2009

Acicular nano-hydroxyapatite (n-HA) was used to make a new biomaterial composite with polycarbonate by a novel technique. The physical and chemical characteristics of the composites were tested. It was found that the synthesized n-HA crystals were similar to bone apatite in size, phase composition and crystal structure. The TEM results indicated the biomimetic n-HA crystals were uniformly distributed in the polymer matrix. Chemical inter-action between inorganic n-HA and polycarbonate was investigated and discussed. These results indicate that the composite fulfills the basic requirement of bone substitute material, and has the potential for clinical applications.
Fabrication of a High Performance Ti Alloy Implant for an Artificial Hip Joint
Authors: Jung Taek Kyun , Abumiya Tadasu , Masahashi Naoya , Kim Mok Soon , Hanada Shuji
Published: August 2009

A new fabrication process of a stem for an artificial hip joint has been investigated to improve mechanical properties and to reduce both the fabrication cost and consumption of expensive Ti alloys by swaging and die-forging into near-net-shape at room temperature, followed by local heat treatment and precise machining. In this study metastable Ti-Nb-Sn alloys consisting of non-cytotoxic elements (biocompatible Ti alloys) were used for biomedical applications. It is found that swaging at both ends of a rod before die-forging saves material consumption by approximately 50% in comparison with turning, and enhances subsequent age-hardening. In addition the cold die-forging enables the fabrication costs to decrease. It is suggested that high strength of higher than 1100 MPa in the proximal part connected to a stem head and low Young’s modulus of less than 60 GPa in the distal part implanted in a femur can be obtained simultaneously in advanced Ti alloy stems.
Polymerization and Characterization of Functionalized Poly(L-Lactide)
Authors: Jin Yu Shun , Xiao Fei , Guo Wen Li
Published: August 2009

Functional poly(L-lactide) (PLLA-OH) containing vinyl groups as well as hydroxyl end groups was synthesized by ring-opening polymerization (ROP), using stannous octanoate as the catalyst and 2-hydroxyethyl methacrylate (HEMA) as the initiator. The structure of the obtained PLLA-OH was characterized using both Fourier Transform Infrared (FT-IR) spectroscopy and 1H nuclear magnetic resonance (1H-NMR) spectroscopy, while their crystallinities and thermo behavior were studied by differential scanning calorimetry (DSC), separately. The best condition for the ROP of the studied PLLA-OH was found with the polymerization temperature of T= 145 °C, the weight percent of the catalyst of 0.03 wt%, the ROP duration of 48 h and the L-lactide/initiator molar ratio of 100/1.
The Comprehensive Utilization of EAF Dust and Pickling Sludge of Stainless Steel Works
Authors: Li Xiao Ming , Zhao Jun Xue , Cui Ya Ru , Yang Jun
Published: August 2009

The EAF Dusts and pickling sludges generated in the stainless steel production contain a lot of valuable metals such as iron, nickel, chromium and manganese. Their compositions are similar to those of laterite nickel ore, and sometimes even better than that at the contents of nickel and chromium. But it is regret that these valuable resources were random piled up or landed fill disposal. In this paper, the typical EAF dusts and pickling sludges and reductant coke powder were mixed in appropriate ratio, and then smelted in a medium frequency induction furnace. In the smelting process, the lime powder and fluorite was added to fluxing, and the ferrosilicon powder was added to strengthen the reduction. The product nickel-chromium-iron can be used as the raw material for stainless steel or cast iron production. The technology has good social and economic benefits.
Design of Inner Wedge-Form Tool in Precision Recycle of Digital Paper Display
Authors: Pa Pai Shan
Published: August 2009

The low yield of ITO thin film deposition is an important factor in optoelectronic semiconductor production. A recycle fabrication module uses micro electroremoving as a precision machining process with a new design of inner wedge-form tool to remove the defective Indium-tin-oxide (ITO) nanostructure from the optical PET surfaces of digital paper display is presented in current studies. The adopted precision recycle process requires only a short period of time to remove the ITO nanostructure easily and cleanly is based on technical and economical considerations and is highly efficient. In the current experiment, a higher feed rate of the optical PET diaphragm combines with enough electric power to drive fast micro electroremoving. A large slant angle of the cathode and a small arc rounding radius of the anode takes less time for the same amount of ITO removal. High rotational speed of the electrodes can improve the effect of dregs discharge and is advantageous to associate with the fast feed rate of the workpiece (optical PET diaphragm). A small rotational diameter of the anode accompanied by a small width of the cathode corresponds to a higher removal rate for the ITO nanostructure.
Binder-Free Pellet Fabrication of Ultra-Fine Poly-Si Powder for Economical Production of Solar Grade Si Ingot
Authors: Kim Bong Hwan , Shin Je Sik , Kim D.S. , Kim Ki Young , Shon In Jin , Moon B.M.
Published: August 2009

The consolidation process of ultra fine Si powders, generated as by-product during the decomposition process of silane gases, was systematically investigated for use as economical solar-grade feedstock. Si powder compacts were tried to fabricate by a consolidation process without a binding agent and then their density ratio and strength were evaluated. The Si powders in as-received state were not pure enough to be used alone as solar grade feedstock material. After the adequate chemical treatments, a sufficiently high purity above solar-grade was able to be achieved.
Thermodynamic Consideration of CaO Added Mg Alloys in Recycling Process
Authors: Lee Jin Kyu , Kim Shae K.
Published: August 2009

CaO addition to Mg forms the Al2Ca and Mg2Ca phases without solid solution even below solubility limit. In this study, thermodynamic considerations of CaO added Mg alloys in recycling process are investigated in comparison with Ca added Mg alloys. Thermodynamic considerations were done by using the army-navy-air force (JANAF) thermochemical tables between Ca or CaO added Mg alloys and fluxes such as MgCl2, KCl, NaCl and MnCl2. The mechanisms during recycling process were thermodynamically discussed. Actual recycling experiments were also carried out to compare the thermodynamic results.
Improving Effect of Mineral Admixtures on Volume Stability of Steel Slag Mortar
Authors: Lun Yun Xia , Zhou Ming Kai , Cai Xiao
Published: August 2009

The effect of two kinds of mineral admixtures (MA) on volume stability of steel slag mortar (SSM) is investigated in order to solve the expansion problem due to steel slag. The rate of linear expansion and flexural strength of SSM containing mineral admixture have been compared with control specimens. Addition of FA and GGBFS slowed down the rate of expansion gain and prolonged the stable ages of SSM. In addition, FA and GGBFS increased later flexural strength of SSM. The improving effect of FA and GGBFS on volume stability of SSM was attributed to the increase of later flexural strength and enhancement of compaction rate.
Properties of Cement Paste Using Mine Tailing and Polymer Materials
Authors: Kim Kyung Nam , Kim Jin Ho , Shin Dae Yong , Lee Beom Goo , Park Hyun
Published: August 2009

In this study, mine tailings obtained in a region near to Youngwol Sangdong(Korea) was used to investigate the contamination of heavy metal ions. Some amount of mine tailings and lignin(AE agent) were added in the general cement pastes, of which the compressive strength and leaching rate were investigated. X-ray fluorescence analysis shows that the major constituents of mine tailings are 56.9wt% of SiO2, 10.8wt% of Fe2O3, 11.2wt% of CaO and 11.4wt% of Al2O3, and the major phases are quartz and calcite. In the content of heavy metal ions, the concentration of As ion is the highest as 257.261mg/ℓ. When mine tailings and lignin were added in cement pastes, the compressive strength was higher in the cement pastes adding only lignin. Lignin addition significantly improved the compressive strength of cement pastes by approximately 15% when being cured in distilled water. The compressive strength was lower in the cement pastes adding mine tailings than in the cement pastes not adding. The leaching rates of Cr, Pb and As ion in distilled water were decreased in the cement pastes adding lignin, compared to in the cement pastes not adding. The leaching rates of all heavy metal ions in the cement pastes curing for 28 days were within the maximum permitted limits in KSLT and EPT method. Therefore, it is thought that mine tailings can be used as an ecological material.
Flexibility Modification of KGM Membranes by Maleic Anhydride
Authors: Chen Yan , Luo Xue Gang , Lin Xiao Yan
Published: August 2009

Konjac Glucomannan (KGM) was modified by maleic anhydride (MA). The influences of processing parameters on the mechanical properties of KGM films were investigated through orthogonal experiments. The results showed that the effects of pH, temperature and time of KGM swelling on tensile strength and folding endurance of modified KGM membranes were insignificant (F<F0.05). The quantity of MA affected slightly on the tensile strength (FF0.01). Folding endurance and tensile strength of KGM membranes could be improved by proper addition of MA. The optimum conditions of KGM modification were that the mixture of KGM and MA was swelling at pH 4.0 and 60°C for 2 h, and then cast on a flat and dried at 50°C to give modified KGM membranes.
Effect on Compressive Strength by Mixing Ratio of MSWI Melting Slag/Bottom Ash
Authors: Lee Woo Keun , Park Eun Zoo , Lee Ji Hyeon , Yoo Yeong Seok
Published: August 2009

In this work, inorganic paste was made from melting slag (MS) of MSWI ash and MSWI bottom ash (MBA) by geopolymer technique. Heavy metals such as Pb and Cu are highly contained in MBA. In the view of environmental protection and resource conservation, recycling of MSWI ash is desirable. MS and MBA were mixed to make inorganic paste. Compressive strength was measured to evaluate the characteristics of inorganic paste after the period of 1, 3 and 7day. Compressive strength of almost 90 MPa was obtained at the mixing ratio of MS : MBA = 9 : 1. And the crystalloid and crystal structure was analyzed by FTIR and XRD. Korea Standard leaching Test (KSLT) is also used to evaluate the environmental safety of inorganic paste. The leached concentration of Pb and Cu were 0.44 ppm and 0.15 ppm, respectively. According to this result, heavy metals were safety immobilized and stabilized.
Adsorption of Phosphate from Aqueous Solution with Blast Furnace Slag Activated by Hydrated Lime as Sorbent
Authors: Li Lin Bo , Zhu Jun , Wang Qi , Yang Jun
Published: August 2009

This paper describes a method of removing phosphate (P) from aqueous solution by sorbent prepared with amorphous blast furnace slag (BFS) and hydrated lime. An orthogonal experiment was carried out to investigate the factors of hydration time, slurrying temperature and the weight ratio of blast furnace slag /hydrated lime and water/solid on the reactivity of the sorbent. Chemical composition of BFS was analyzed by atomic absorption spectrometry, microstructure and phase analysis of samples were conducted by SEM and XRD. It is found that all sorbents prepared show higher P adsorption capacity than single blast furnace slag.
Investigation of Electronic Structures of F-Doped TiO2 by First-Principles Calculation
Authors: Cui Ying , Du Hao , Wen Li Shi
Published: August 2009

F-doped TiO2 has exhibited superior photocatalytic activity. However, its electronic structures and photocatalysis mechanism are still unclear. In the present work, the structural optimization and electronic structure of F-doped anatase TiO2 have been investigated by means of the first-principles pseudopotential total energy method. It has been demonstrated that F doping would modify the valence band at the lower energy direction in the F-doped TiO2. Calculation results confirm that doping of fluorine would not shift the absorption edge into the visible light region. Instead, we attributed its photocatalytic activity to the enhancement of the oxidative power of F-doped TiO2.
Indium-Sensitized UV Photocatalysts Made from Alkali Titanate Microfibers
Authors: Torres-Martínez Leticia M. , Sánchez-Trinidad Cecilia , Rodríguez-González Vicente , Gómez Ricardo
Published: August 2009

Indium-alkali microfibers doped ceramic were prepared by the sol-gel process. The gels preparation samples, were heat treated at 700°C for different length of time. The products were characterized by means of XRD, SEM-EDS and UV–Vis-DRS. The XRD showed the formation of the Na2Ti6O13 phase whose crystallinity depends on the annealing time. The band gap calculated from the UV–Vis Kubelka-Munk function shows very similar values (3.53-3.55 eV). The SEM images of the indium-alkali titanates show microfiber clumps morphologies of about 5 µm, and the EDS spectra show that In2O3 is on the Na2Ti6O13 surface. The results of the evaluation of the In-Na2Ti6O13 semiconductors in the 2, 4-dichlorophenoxyacetic acid (2, 4-D) photodecomposition under UV light irradiation, show that the photoactivity depends on the time of heat treatment of the samples.
Preparation and Characterization of Fe-Doped BiVO4
Authors: Liang Li Li , Luo Xue Gang , Lin Xiao Yan , Xu Chang Gang , Zhao Zhao
Published: August 2009

Monoclinic crystal bismuth vanadate (BiVO4) was synthesized by the high temperature solid state reaction after ball milling the materials of Bi2O3 and V2O5. The influences of sintering times on the crystal phases and structures of BiVO4 powders were studied through the XRD、FTIR characterization. Fe-doped BiVO4 was prepared by doping ferric chloride to pure monoclinic crystal BiVO4 to improve the photo absorbance performance of BiVO4 and to promote the isolation of photo-induced carriers. Visible light activity of BiVO4 and Fe-doping BiVO4 were characterized using the UV-diffuse reflectance spectroscopy. The electrochemical behaviors of BiVO4 and Fe-doping BiVO4 were investigated under the condition of avoiding light or under light.
Photocatalytic Properties of TiO2-Coatings Mounted on CaAl2O4:Eu2+, Nd3+ without Light Source
Authors: Li Hui Hui , Wang Yu Hua
Published: August 2009

This paper aims at the investigation of photocatalytic properties of titanium dioxide coatings covering on the surfaces of long blue-emitting afterglow CaAl2O4:Eu2+, Nd3+ elaborated by a sol-gel method. Morphologies and microstructures of the coatings were observed mainly by transmission electron microscopy (TEM) and analyzed by X-ray diffraction (XRD). The photocatalytic behavior of the TiO2-base surfaces was evaluated by the degradation of methyl orange (MO) solution. It suggested that a layer of TiO2 film mounted on the phosphor particles successfully. Also, the TiO2 coatings had remained its photocatalytic role on the as-prepared sample even after the light source was removed. The inner long blue-emitting afterglow had released blue afterglow after removing light source and allowed for reactive TiO2 surfaces to be held for the removal of methyl orange.
A New Preparation Method of Visible Light Responsive Titanium Dioxide Photocatalytic Films by Sol-Gel Method
Authors: Nishizawa Kaori , Miki Takeshi , Watanabe Eiji , Taoda Hiroshi
Published: August 2009

Two types of titanium dioxide sol solutions were prepared using titanium tetra-isopropoxide, urea, 2-methoxyethanol and water. The prepared sol solutions were dip-coated onto fused silica plates. These as-prepared films were dried at 100 °C and then annealed at 650 °C. The annealed films were anatase type titanium dioxides. Visible light absorption by the films was observed in wavelengths longer than 400 nm. Also, photodegradation of methylene blue by visible light irradiation was accelerated in the presence of the films prepared by these methods.
Synthesis of Mn-N-Codoped TiO2 Photocatalyst and its Photocatalytic Reactivity under Visible Light Irradiation
Authors: Hu Yun , Zhang Xia , Wei Chao Hai
Published: August 2009

Visible-light responsible Mn-N-codoped TiO2 nanocrystal photocatalysts were synthesized for the first time by a simple hydrothermal synthesis method. X-ray powder diffraction (XRD) measurement indicated that all of the photocatalysts have an anatase crystallite structure and the increase of the doping concentration had less effect on the structure and particle size. Comparing to N-doped TiO2, a shift of the absorption edge of Mn-N-codoped TiO2 to a lower energy and a stronger absorption in the visible light region were observed. The Mn-N-codoped TiO2 showed a higher photocatalytic reactivity than undoped TiO2 and N-doped TiO2 for the photodegradation of rhodamine B (RhB) under visible light irradiation. The doping concentration had an optimal value, according to the highest photocatalytic activity. This suggested that Mn and N codoping has important effects on the improvement of visible-light responsible photocatalytic activity.
Preparation of Titanate Nanotubes by Hydrothermal Method
Authors: Yu Dan Ni , Liu Wen Xiu , Ma Jing , Qu Xiao Guang , Cao Wen Bin , Zhang Zhong Ying , Mao Jing Hong
Published: August 2009

Titanate nanotubes have been directly prepared by hydrothermally treating P25 powders in NaOH aqueous solution. Effect of calcination temperature on crystal phase, morphologies and specific surface area of the as-synthesized nanotubes has been investigated in detail. The Na2Ti3O7 tubular structure could be kept well even after calcination at 600 °C and began to transform to Na2Ti6O13 nanorods at around 645 °C. The specific surface area of the as-synthesized nanotubes was 200.6 m2/g and reached to the maximum of 347.9 m2/g after calcination at 300 °C and then decreased sharply with the further increase of the calcination temperature.
Micro Mechanical Property Measurement of Nickel (99.9%) Thin Film Using Vision Strain Measuring Method
Authors: Han A. Ruem , Lee Hye Jin , Lee Nak Kyu , Lee Geun An , Song Jung Han
Published: August 2009

Mechanical properties of micro-electro-mechanical systems (MEMS) materials are increasingly important with the wide use of miniaturized systems. This paper deals with development of the strain measurement module for micro materials tests. Vision strain method (VSM) and actuating stroke method (ASM) are adopted in the strain measurement module in order to reduce the discrepancies between the measured deformation and actual one in the specimen. With the developed strain measurement system, a number of tensile tests were concluded for 99.9% nickel thin films with the thickness of 500µm. Specimens with various widths from 1 mm to 2mm and with various lengths from 2mm to 4mm were used in the tests. From the experiment, material properties such as yield strength, tensile strength, fracture strength, fracture strain and young’s modulus are analyzed with stress-strain curves of 99.9% nickel thin film.
Photocatalytic Activity of Porous TiO2 Film Prepared by Dip-Coating Technique Using Sol Containing Trehalose
Authors: Miki Takeshi , Nishizawa Kaori , Watanabe Eiji , Taoda Hiroshi
Published: August 2009

To obtain porous and thick TiO2 film, the precursor sol was prepared by hydrolysis of Ti isopropoxide and then complexed with trehalose dihydrate. The porous TiO2 film was fabricated by dip-coating technique on quartz glass substrates using this sol. The TiO2 films were calcined at 500-700 °C. The photocatalytic activity of the films was evaluated by examining decomposition of methylene blue in aqueous solution under UV light irradiation. The TiO2 film prepared from the sol with trehalose was more active than TiO2 film prepared from the sol without trehalose. The trehalose addition to the dip-coating solution was effective in improving the photocatalytic activity of the TiO2 film.
Preparation of TiO2 Thin Films and its Superhydrophilic Properties
Authors: Ma Jing , Liu Wen Xiu , Qu Xiao Guang , Yu Dan Ni , Cao Wen Bin
Published: August 2009

TiO2 thin film was prepared on soda lime glass by hydrolysis of Ti(OC4H9)4 in alcoholic solutions by sol-gel method combined with spin-coating and calcination different temperatures. Prepared samples were characterized by XRD, FESEM, and measurement of contact angles and transmittance. XRD identification reveals that the films are composed of anatase TiO2 when the annealing temperature was set at 450~550 oC. SiO2 layer was coated on the surface of the glass firstly to barrier the diffusing of sodium ions from the substrate. Light-induced superhydrophilicity of the TiO2 thin film has been investigated. To increase the illumination light intensity will decrease the water contact angle. The superhydrophilicity of the TiO2 thin film will disappear more slowly in the dark than that in the field of ultrasound.
Light Conversion by Size Control of Inorganic Phosphors
Authors: Cho In Churl , Park Yong Kap , Choi Yong
Published: August 2009

A unique method, so called, hydro-thermal synthetic method was applied to produce nano-sized inorganic blue (Y2SiO5:Ce) and red (Y2O2S:Eu+3) emitting phosphors. Electron microscopy revealed that the nano-sized emitting phosphor particles have spherical shape with 23-50nm in size. The particles can effectively change ultraviolet rays of 1-390 nm to infrared rays of 750nm -1mm, which are suitable to promote the growth of plants. The principle excitation and emitting spectrum of the red phosphor in 590-700 nm emitting spectrum were in the region of 308nm and 617nm, respectively, whereas, those of the blue phosphor in 420-470nm emitting spectrum were in the region of 254nm and 464nm, respectively. The addition of 0.1-0.2 wt% of the 2:1 mixed red and blue powders to a film showed the maximum emitting intensity of 537x1000 count/sec.
Properties Predicting of Transition Metal-Doped Anatase TiO2
Authors: Qu Xiao Guang , Liu Wen Xiu , Ma Jing , Yu Dan Ni , Cao Wen Bin , Mao Jing Hong
Published: August 2009

The binding energy of anatase TiO2, in which the Ti was substituted by other transition metals in the 4th, 5th and 6th periods of the periodic system of the elements, has been calculated by using first principles method. The doping limits of V, Cr, Zr, Nb, Mo and W are 61.5%, 39.7%, 88.2%, 100.0%, 65.0%, and 63.2%, respectively predicted by the calculated binding energy, while the doping limits of other transition metals are much lower. So, these transition metals can easily be doped into the anatase structure theoretically while it is difficult for the others. And the band structure and density of states (DOS) of V, Cr, Zr, Nb, Mo and W doped anatase TiO2 have also been calculated and analyzed.
Development of Porous Material with High Young’s Modulus and Low Thermal Expansion Coefficient in SiC-Vitrified Bonding Material-LiAlSiO4 System
Authors: Ono Tatsuya , Matsumaru Koji , Juárez-Ramírez Isaías , Torres-Martínez Leticia M. , Ishizaki Kozo
Published: August 2009

Machines for manufacturing large scale flat displays are enlarging as the size of glasses increases. This work develops porous materials with a low thermal expansion coefficient and a high Young’s modulus. SiC and LiAlSiO4 were used for a positive and a negative thermal expansion materials, respectively. Compositions of powders for porous materials were determined to obtain a desirable Young’s modulus and thermal expansion coefficient by using SiC-VBM-LiAlSiO4 phase diagram at 20 % of porosity. The empirical values of Young’s modulus and a thermal expansion coefficient are close to the theoretical values by using the diagram. Fabricated porous material had high enough Young’s modulus of 87 GPa, and low enough thermal expansion coefficient of 2 x 10-6 K-1 at temperatures ranging from -17 °C to 190 °C with 22 % of porosity.
Preparation of Superfine Molybdenum Powder by Reduction Process
Authors: Chen Xiang Yang , Bu Chun Yang , Lan Xin Zhe , Zhao Xin Rui
Published: August 2009

The principle and process of producing molybdenum powder via reduction reaction of molybdenum trioxide at lower temperature in a N2-H2 system were researched. The effects of hydrogen concentration, temperature, and volatilization rate of molybdenum trioxide on particle size were analyzed. The experimental results showed that the optimal process parameters were 770°C-790°C in 60min when the hydrogen flow rate was 700mL/min. Particle size of superfine molybdenum powder was less than 4μm. The concentrations of hydrogen, temperature and volatilization rate of molybdenum trioxide have great effect on the particle size of superfine molybdenum powder.
Preparation and Characterization of Sulfonated Poly(ether Sulfone) Using 4,4-Bis(4-Hydroxylphenyl)valeric Acid for Proton Exchange Membrane Fuel Cell Application
Authors: Seo Dong Wan , Lim Young Don , Islam Mollah M. S. , Lee Soon Ho , Moon Sang Ho , Pyun Sang Young , Kim Whan Gi
Published: August 2009

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 BH3 solution 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. A series of copolymers were studied by 1H-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. The S-PES membranes exhibited proton conductivities from 1.20  10-3 to 3.40  10-3 S/cm, water swell from 12.25 to 31.50 %, IEC from 0.43 to 0.72 meq/g and methanol diffusion coefficients from 3.60  10-7 to 4.90  10-7 cm2/S at 25 °C.
Electrodeposition of Nanocrystalline CoNiFe Thin Films Prepared by Cyclic Voltammetry
Authors: Cai Chao , Wang Qiu Ping , Zhang Zhao , Yang Jian Feng
Published: August 2009

The electroplating behavior of nanocrystalline CoNiFe soft magnetic thin film with high saturation magnetic flux density and low coercivity was investigated using cyclic voltammetry and chronoamperometry methods in conjunction with the scanning electron microscopy (SEM/EDX) and X-ray diffraction (XRD) techniques. The results show that, the co-deposition of CoNiFe alloy behaves anomalously. And the nucleation/growth process of CoNiFe ternary alloy followed 3D instantaneous mechanism at higher potentials, while in the case of lower potentials it followed 3D progressive mechanism.