bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on MWCNTs Catalyze Electrogenerated Chemiluminescence of Ru(bpy)32+
Authors: Guo Wei Ling , Li En Zhong , Yang Da Xiang , Chen Hao , Wang Hai Dou , Xu Bin Shi
Published: August 2011

Carbon nanotubes (CNTs) have the ability to promote electron transfer reaction when used as electrode materials in electrochemical reaction owing to their high electronic conductivity. The modified glassy electrode coated with multi-walled nanotubes (MWCNTs/GC) is used to detect Electrogenerated Chemiluminescence (ECL) of Ru(bpy)32+ aqueous solution. When the applied potential on the working electrode is at at positive potential of +0.3 V (s. Ag/AgCl), a strong cathodic ECL of Ru(bpy)32+ is observed。This property of MWCNTs/GC is used to examine dopamine (DA) in solution.
The Influnence of the Amplitude and Frequency of Sweeped Magnetic Field on the Exchange Bias and Coercivity for Ferromagnetic / Antiferromagnetic Films: Monte Carlo Simulation
Authors: Zheng Wen Ting , Jiang Li Qin , Huang Zhi Gao
Published: August 2011

The influnence of the amplitude (H0) and frequency of sweeped magnetic field on the exchange bias He and coercivity Hc for ferromagnetic/ antiferromagnetic films has been simulated with Monte Carlo method. In a cycle, the sweeped frequency is inversely proportional to Monte Carlo steps (MCSs). It is observed that, for smaller MCSs, the values of He and the blocking tempreture Tb reduce evidently with increasing MCSs; for larger MCSs, the values of He and Tb decrease gently with increasing MCSs. It is also found the values of He and Tb decrease obviously with increasing values of H0 (HN0). However, on the contrary, the value of Hc increases with increasing values of H0 (HN0). At low temperature and little HN0, the asymmetric loop may appear, which is attributed to the competition between the relaxation time and the period of the external magnetic field. Moreover, the symmetry of the loops influences evidently the values of He and Hc.
Structure and Spectrum of (IrnN)0, ± (n=1~6) Clusters by Density Functional Theory Methods
Authors: Zhang Xiu Rong , Cui Yan Na , Li Yang
Published: August 2011

The first systematic study of the (IrnN)0,± (n=1~6) clusters was herein presented by using the B3LYP method of density functional theory (DFT) with the LANL2DZ for Ir atoms and the 6-311+G (3df) for N atoms. The result showed that the ground state configurations of the (IrnN)0, ± (n=4~6) clusters were all three-dimensional. There were much more absorption peaks in the Raman spectrums of Ir3N, (Ir4N)0,+ and (Ir6N)0,± clusters than other clusters. There was no absorption peak only just in the IR and Raman spectrums of the (Ir4N)- cluster in the small frequencies. The outcome is very useful to validate the predicted trend of structural transitions experimentally.
High-Yield Synthesis of Bamboo-Like BN Nanotubes Using Self-Propagation High Temperature Synthesized Porous Precursor
Authors: Zhang Lai Ping , Wang Ji Lin , Gu Yun Le , Zhao Guo Wei , Qian Qiong Li , Li Jie , Pan Xin Ye , Zhang Zhan Hui
Published: August 2011

High-yield and high-purity bamboo-like boron nitride nanotubes were synthesized via an effective chemical vapor deposition method by annealing porous precursor under ammonia atmosphere at 1150 °C. The porous precursor, prepared by self-propagation high temperature synthesis method, was the key to bulk synthesis process. The as-synthesized boron nitride nanotubes were characterized by SEM, TEM, HRTEM, XRD, Raman and FTIR spectroscopy. These nanotubes had a bamboo-like structure with uniform diameters about 90 nm and length of more than 10 μm. The associated growth model is proposed in this paper.
The Thermal Stress between the Interfaces of Different Materials of the Axis Symmetric Structural
Authors: Liu Hu Ran
Published: August 2011

In researching the thermal transmit and elastic thermal stress properties between the interfaces of different materials, such as the bricks and the fire – resistant soil in the annual structural of the blast furnace. This paper presents a axis symmetric model to calculate the temperature, the elastic deformation and the stress. This model has the advantages of high accuracy, simple in structure and easy in calculation. The research of the thermal stress by the interfaces mechanics has never been reported before.
Preparation of Visible-Light Responsive Photocatalyst SxTi1-XO2
Authors: Wang Yong Qiang , Liu Fang , Zhao Chao Cheng
Published: August 2011

Sulfur-doped titanium dioxide powders (SxTi1-xO2) was prepared by calcinations, that is, the hydrolysis of acidic tetra-butyl tianate using thiourea in ethanol, followed by calcinations at temperatures about 500°C. Based on the characterizations of XRD, BET, surface photovoltage spectroscopy (SPS), electric-field-induced surface photovoltage spectroscopy (EFISPS) and XPS, it was found that the sulfur could restrain the crystallization transformation of TiO2 from anatase to rutile, although the calcinations temperature has attained 500°C, the crystallization still were anatase entirely. The catalysts exhibited photocatalytic activity in the visible light region owing to S-doping. The light absorption onset of SxTi1-xO2 was shifted to the visible region at 550nm compared to 329nm of pure TiO2. In the crystal, the S atoms occupied some of the lattice titanium atoms for form S-O bonds. Photocatalytic decomposition of benzoic acid solutions was carried out under simulated sun light, and the SxTi1-xO2 catalyst showed higher activity than pure TiO2.
Research on Chip Breaking Feature of the Micro Hole Vibration Drilling
Authors: Zhang Peng , Guo Xing Yu , Zhao Kang Pei , Zhu Li You
Published: August 2011

It is often one of the most important issues for chip breaking and chip removal problems in the hole machining process, especially for micro hole. The chip breaking mechanism of the vibration drilling is researched, and its chip breaking conditions is analyzed. The micro drilling experiments are carried to contrast the chip shape of common drilling and vibration one. It can be draw that the vibration drilling can realize the regular chip breaking, which is beneficial to chip removal in hole machining, the chip breaking feature is one of the fine process effects. This work further enriches the vibration drilling technology.
Synthesis of Porous MgO into Sheet-Like Structure via Solution Routes
Authors: Abu Bakar Maria , Azmi Abdul Hamid Muhammad , Jalar Azman , Shamsudin Roslinda
Published: August 2011

A simple solution route employing the reaction of magnesium acetate tetrahydrate ((CH3COO)2Mg.4H2O) and hexamethylenetetramine (C6H12N4) has been demonstrated to successfully grown MgO thin film on both Mg and MgO substrates at two different temperature i.e 90 °C and 150 °C for 4 h. Morphological observations revealed that the porous structure of MgO film was obtained on Mg substrate while sheet-like structure film was observed when using MgO substrate. EDX indicated only Mg and O were present in all films. The MgO bandgap obtained varies with type of substrate used and temperature. The MgO film growth on Mg substrate bandgap increased from 5.18 eV to 5.27 eV with temperature increased from 90 °C to 150 °C. Similar increased was also observed with MgO film growth on MgO substrate. However the results obtained are well below of MgO bulk energy bandgap. This was probably due to non-stoichiometry of deposited layers and crystallinity of the samples as shown by EDX and XRD results respectively.
White Organic Light-Emitting Diode Based on Organic Quantum Well Structure
Authors: Wen Liang , Li Fu Shan , Guo Tai Liang
Published: August 2011

A white organic light-emitting diode (WOLED) with an organic quantum well structure of ITO/N,N’-diphenyl-N,N’-bis(3-methylphenyl)-1,1’-biphenyl-4,4’-diamine (TPD) / 4,7-Diphenyl-1,10-phenanthroline (Bphen)/5,6,11,12-tetraphenylnapthacene (Rubrene)/Bphen /LiF/Al was fabricated by vacuum evaporation. The electroluminescence (EL) spectrum of the as-fabricated WOLED covers from 380nm to 700nm of the visible light region with a blue emission from TPD and an interesting wide emission peaked at 525nm, which can be decomposed into three emissions at 480nm, 525nm, and 555nm, respectively. The peaks at 525nm and 555nm are attributed to the excitation emission from the Bphen/Rubrene/Bphen quantum well structure, which are obviously blue-shifted in comparison with the photoluminescence (PL) spectrum of Rubrene. The new peak at 480nm is attributed to the exciplex emission at TPD/Bphen interface since it was also observed in the PL spectra. The white light of the WOLED comes from combined contribution of exciplex emission and organic quantum well structure.
Research on some Schiff Base Compounds with Aromatic Substituted Groups and their Cu-Complexes
Authors: Jiao Ti Feng , Yang Na , Zhou Jing Xin
Published: August 2011

Some Schiff base compounds with aromatic substituted groups and their Cu-complexes have been designed and synthesized from the reaction of aromatic amines with salicylaldehyde. It has been found that depending on the molecular structures and substituted groups, the formed Schiff base compounds showed different properties, indicating distinct regulation of molecular design. UV and IR data confirmed commonly the formation of Schiff base and coordination with Cu(II) ions, as well as aromatic segment in molecular structures. In addition, the process of ex situ coordination seemed to change differently along with adding time, which could be ascribable to the presence of distinct substituted group and change of reaction activity. The spectral difference is mainly attributed to molecular structures, formation of Schiff base group and different substituted groups. The present results have showed that the special properties of Schiff base compounds could be turned by modifying molecular structures and substituted groups, which show potential application in fields of functional material fields such as liquid crystal and catalysts.
Passive Q-Switching with Graphene Saturable Absorber in Nd:YAG Operating at 1064nm
Authors: Jiang Man , Ren Zhao Yu , Zhang Yu Ping , Lu Bao Le , Zhang Ren Jian , Guo Jia Xi , Zhou Yi Xuan , Bai Jin Tao
Published: August 2011

A graphene-PVA film is fabricated by using polyvinyl alcohol(PVA), which provides excellent mechanical property and easy operation. Based on the numerous advantages of graphene in optical and mechanical characteristics,Graphene was used as absorber with passively Q-switched Nd:YAG solid laser in our experiment. Furthermore, there are no changes in the structure and characteristics of graphene. Inserting our graphene-PVA SA mirror to the Nd: YAG laser, we ultimately get that the single pulse energy is about 7.68μJ, and that the shortest pulse width is about 640ns. The experiment results prove that our graphene-PVA SA mirror is feasible and suitable for Q-switched lasers.
Synthesis of Al-Substituted 11Å Tobermorite from Aegirine-Augite Syenite Potash Ores by Hydrothermal Reaction at 300°C
Authors: Liu Yu Qin , Xia Hong Tu , Ma Hong Wen
Published: August 2011

The Al-substituted 11Å tobermorite was synthesized from aegirine-augite syenite potash ores by alkaline hydrothermal reaction at 300°C. The obtained tobermorite was characterized by chemical analysis, X-ray diffraction and scanning electron microscopy. The effect of reaction time on the tobermorite formation and the dissolution ratio of the K2O in the potash ores were investigated. It was revealed that the dislocation ratio of K2O increases with increasing reaction time. The main rock constituents were converted into a well-crystallized Al-substituted 11Å tobermorite after 3 hours hydrothermal reaction at 300°C. The obtained Al-substituted tobermorite forms hollow spherical aggregates with the diameter of 40µm-80µm by the crossing of fibrous tobermorite crystal together. The Al3+ may substitute isomorphously up to 15 at % of Si 4+ in the obtained tobermorite.
Study on Flame Retardant and Anti-UV Finishing Technology of Cotton Knitted Fabric
Authors: Di Jian Feng , Xu Jie , Du Wen Qin
Published: August 2011

The coating agent was prepared by adding nano-titanium dioxide(nano-Tio2) and flame retardant to solvent-based polyurethane(PU),then applied to cotton knitted fabric which was finished by padding flame retardant through transfer coating technique, so a multifunctional coating fabric with flame retardancy and anti-UV property was manufactured. Discussing the changes in flame retardancy and anti-UV property with the increase in addition of flame retardant and nano-titanium dioxide. The results showed that the fabric has good flame retardancy and anti-UV property.
Combination of Microemulsion for Topical Deliverying Tripterygium Wilfordii Multiglycoside
Authors: He Xin , Zhao Xing Hua , Ou Yang Wu Qing
Published: August 2011

The purpose of this study was to explore the potential application of the combination of microemulsion as a topical delivery vehicle in enhancing the absorption and efficacy of tripterygium wilfordii multiglycoside (TWM). Various microemulsion formulations were developed and an optimal microemulsion (TWM-ME)，which presented spherical droplets and consisted of RH-40, IPM and water was 27: 3.3: 69.7 by weight. It possessd an average droplet size of 23.6 nm, a low viscosity of (3.56±0.12) mm2•s-1 Zeta electric potential was (–5.35±0.42) mV, refractive index was (1.3617±0.0051) nD20, conductivity was (97.6±3.6) μs/cm. Compared to the control solution, TWM-ME provided better skin permeability in vitro. Moreover, TWM-ME has noticeable anti-inflammatory and immune suppression effect. These results indicate that the combination of microemulsion represents an effective vehicle for topical delivery of TWM.
Atomic Force Microscopy-Based Investigation on the Elastic Properties of Oligodendrocytes
Authors: Wang Jing He , Yu Miao , Liu Li , Zhao Jie , Liang Ying Chun , Dong Shen
Published: August 2011

As the leading killer of human health in the current age, cancer is concerned widely in the medical profession. As the popularizations of atomic force microscopy (AFM) in micro-biology, measuring the mechanical properties of cells by AFM is gradually applied in the diagnosis and treatment of cancer. In this paper, the scanning parameters were optimized and the indentation experiments in different parts of oligodendrocytes were carried out to test the elastic modulus of oligodendrocytes. In order to evaluate the elastic modulus accurately, nine areas on each cell were selected, and for each area, a small matrix of indentation point was made. The results indicated that elastic modulus of the center part of cancer cell is softer than that in the edge, and the one of the normal cell are 3 order of magnitude harder than the cancer cell.
Molecular Dynamics Simulation of Relaxation and Local Structure Change of a Molten Cu135 Cluster during Rapidly Quenching
Authors: Xu S.N , He N. , Zhang L.
Published: August 2011

Relaxation and local structure changes of a molten Cu135 cluster have been studied by molecular dynamics simulation using embedded atom method when the cluster is rapidly quenched to 700K, 600K, 500K, 400K, 300K, 200K, and 100K. With decreasing quenching temperature, details of energy evolvement and relaxation are analyzed. The simulation results show that the final structures are molten at 700K, like-icosahedral geometry at 600K-200K, non-crystal at 100K. The average energy of atoms is the lowest at 500K, and in the relaxation has abrupt increase at 25,135 and 42ps separately at 400K, 300K, and 200K. The simulation reveals that the quenching temperature has great affect on the relaxation processes of the Cu135 cluster after β relaxation region.
The Simple Method in Grinding the Carbide Burs of the Shape of a Cone Upside down
Authors: Liu Hu Ran
Published: August 2011

The carbide rotary burs with the shape of a cone upside down are kind of very special cutting tools. They have a very important application in model machining. And the function could not be substituted by any kind of other cutter. This paper uses a hyperboloid of one sheet to imitate the cone, uses the straight rural line as the cutting edge, and presents a simple method to machining this kind of cutter with helical cutting edges. Only the tradition machine tool is needed for the generation of this kind of complicated cutting tools.
An Efficient Catalysis-Oxidation Method for the Degradation of Phenol in Wastewater
Authors: Bin Wu , Chai Duo Li
Published: August 2011

In this study, we developed an efficient catalysis-oxidation method for the degradation of phenol in wastewater, in which the Fe3O4 nanocrystals and H2O2 were employed as catalyst and oxidation agents respectively. Firstly, Fe3O4 nanocrystal coated with PEG was prepared via an oxygenation-deposition hydrothermal method, TEM, FT-IR, BET and XRD characterization indicated that the prepared Fe3O4 nanocrystals had an average size of 26 nm and the specific surface of 35.25 m2/g. Using the prepared Fe3O4 nanocrystals as catalyst, the phenol in wastewater was efficiently degraded by H2O2. The degradability of the phenol was investigated by FT-IR, HPLC and UV–visible spectrophotometer, and the experimental results showed that the phenol was efficiently degraded by H2O2 and the Fe3O4 nanocrystals could be efficiently recycled. Finally, the possible catalytic reaction mechanisms and pathways of phenol degradation were discussed.
Adsorption Mechanism of Copper(II) Ions on Expansion-Treated Rice Husk
Authors: Liang Xuan , Luo Xue Gang , Lin Xiao Yan
Published: August 2011

Expansion-treated rice husk (ERH) had been used as adsorbent for removing copper(II) ions, and showed strong adsorption ability and removal efficiency for copper(II) ions. In this paper, the surface and bulk structures of ERH adsorbent were investigated by X-ray photoelectron spectroscopy (XPS) and scanning electronic microscopy (SEM), ERH was treated by water solution with different pH value, and the adsorption performance of ERH for copper(II) ions was investigated through adsorption static experiments in order to study the adsorption mechanism. The result showed that ERH treated by alkaline solution had high removal efficiency for copper(II) ions, the reason ascribed to the large surface area of ERH. ERH had competitive adsorption for H+ and Cu2+, and a monolayer adsorption process played an important role in the whole process.
Photoemission and Energy Gap of CdS Synthesized by Solid State Microwave-Plasma
Authors: Promnopas Wonchai , Thongtem Titipun , Thongtem Somchai
Published: August 2011

Purified cadmium sulfide crystals were successfully synthesized from 1:2 molar ratio of Cd and S powders by a 900 W microwave plasma for 120 min and 140 min. In the present research, XRD and SAED patterns including SEM, TEM, and FIB images were used to indicate phase and morphology of the products, with their Raman peaks at 303 and 605 cm-1. Photoemission was determined to be 537 nm, and direct energy gap (Eg) to be 2.48-2.51 eV.
Size Reduction of Gold Nanoparticles by Pulsed Laser Ablation and Re-Irradiation in Water Media
Authors: Pimpang Pichitchai , Wongratanaphisan Duangmanee , Gardchareon Atcharawan , Choopun Supab
Published: August 2011

Gold nanoparticles (Au NPs) were prepared by using pulsed laser ablation with and without cover slide. The cover slide was used to confine atoms/ions in order to reach supersaturation condition. The obtained Au NPs were investigated by UV-vis spectroscopy, transmission electron microscopy (TEM), and zeta potential measurement. The absorbance spectra exhibited its absorption peak at around 520 nm for both Au NPs ablating with and without cover slide. It was found that Au NPs ablating with cover slide exhibited smaller size and size distribution (10.6 ± 5.9 nm) than those of without cover slide (34.1 ± 21.5 nm) at laser power of 5.00 mJ/pulse. This is due to supersaturation effect and re-irradiation effect caused by cover slide that trapped atoms/ions of gold and trapped Au NPs, respectively. Also, the zeta potential of Au NPs had a negative value suggesting negative surface charge. The lowest zeta potential was observed for Au NPs ablating with cover slide at 5.00 mJ/pulse and it was in consistent with an observation of the highest pH value. In addition, the Au NPs ablating with cover slide at 5.00 mJ/pulse showed the least change with time indicating the most stable Au NPs which was in consistent with the lowest zeta potential results. Thus, pulsed laser re-irradiation could be used for size reduction of Au NPs prepared by pulsed laser ablation in water media.
Reactive Compatibilization of Polylactide, Thermoplastic Starch and Poly(butylene adipate-co-terephthalate) Biodegradable Ternary Blend Films
Authors: Phetwarotai Worasak , Aht-Ong Duangdao
Published: August 2011

Biodegradable blend films of polylactide (PLA), thermoplastic starch (TPS), and poly(butylene adipate-co-terephthalate) (PBAT) were prepared through reactive modification. Three types of compatibilizers, methylenediphenyl diisocyanate (MDI), maleic anhydride (MA), and MA-g-PE, were studied. PLA and PBAT were blended in the presence of the compatibilizer to improve and evaluate the interfacial interaction. PBAT content was varied from 0 to 20 wt%, while compatibilizer content was differed from 0 to 5 wt% based on PBAT amount. For ternary blending, PLA, TPS, and PBAT were melt-blended with and without compatibilizer in a twin screw extruder using glycerol and tapioca starch as plasticizer and filler, respectively. The effects of type and content of compatibilizer and blend compositions on the physical, thermal, morphological, and tensile properties of the films were investigated. The results showed that the blend films with MDI had appropriate physical, thermal, and tensile properties. The presence of small amount of MDI enhanced the thermal and tensile properties of the films compared to the uncompatibilized films. This can be explained by a uniform morphology of the dispersed phase in the PLA matrix.
Effect of Sintering Temperature on Microstructure and Mechanical Properties of Al2O3/TiAl In-Situ Composites
Authors: Xiang Liu Yi , Wang Fen , Zhu Jian Feng , Wang Xiao Feng
Published: August 2011

Al2O3/TiAl composites were successfully fabricated by hot-press-assisted exothermic dispersion method with powder mixtures of Ti, Al, TiO2and Cr2O3as raw materials. The effect of sintering temperature on the microstructures and mechanical properties of Al2O3/TiAl composites has been investigated. The results show that the Rockwell hardness and density of the composites increased with increasing sintering temperature. But the flexural strength and fracture toughness peaked at 825 MPa and 7.29 MPa·m1/2, respectively, when the sintering temperature reached to1300 °C.
Fabrications and Evaluations of Hydrogen Permeation on Al2O3-CuO-ZnO(ACZ)/Pd Coated Membrane
Authors: Kim Kyeong Il , Yoo Sung Woong , Lee Na Ri , Hong Tae Whan
Published: August 2011

The most promising methods for high purity hydrogen production are membranes separation such as polymer, metal, ceramic and composites. It is well known that Pd and Pd-alloys membranes have excellent properties for hydrogen separation. However, it has hydrogen embrittlement and high cost for practical applications. Therefore, most scientists have studied new materials instead of Pd and Pd-alloys. On the other hand, ceramic materials are great in resistance to acids and chemically stable under high operating temperature. Recent research in cermet materials for membrane applications interests to permeability and selectivity of hydrogen. High purity hydrogen can be produced through simple process by membrane. Recently, research in ceramic composites for membrane applications attract to hydrogen separation. Porous ceramic membrane process which has high permeability and hydrogen flux is chemically and thermally stable. Therefore, they are attractive for applications in hydrogen production process. However, porous ceramic membrane had low selectivity, hard to produce high purity hydrogen. Many studies were carried out Pd and Pd alloys coating, they were fabricated dense cermet membrane. In this work, ACZ ceramic membrane was fabricated disk type membrane by cold isostatic press (CIP) and then coated Pd and Pd-alloys.. It was characterized by XRD, SEM, EDX and BET. Also, we estimated the hydrogen permeability by Sievert's type hydrogen permeation membrane equipment.
Improvement of Strength of Lotus-Type Porous Aluminum through ECAE Process
Authors: Kim Tae Bum , Tane Masakazu , Suzuki Shinsuke , Ide Takuya , Utsunomiya Hiroshi , Nakajima Hideo
Published: August 2011

Lotus-type porous aluminum with cylindrical pores oriented in one direction was deformed by Equal Channel Angular Extrusion (ECAE) through a 150° die with sequential 180° rotations, and the pore morphology and Vickers hardness after the extrusion were investigated. The Vickers hardness increases with increasing number of passes in the extrusions both parallel and perpendicular to the pore direction, accompanied by the decrease of porosity. The densification occurs more easily in the perpendicular extrusions than in the parallel extrusions, and the large deformation by the densification gives rise to the large increase in the Vickers hardness for the perpendicular extrusions.
Strength Enhancement of Bottom Ash-Based Concretes Using Metakaolin
Authors: Zhao J. M. , Yang Z. X. , Hwang Kyu Hong , Kim M. C.
Published: August 2011

To replace bottom ash for natural sand completely, the mix proportions of bottom ash in concrete was adjusted according to tab density and replacement ratio of Metakaolin/Cement were established. And then testing for slump, setting time, and compressive strength was conducted. According to test results, the compressive strength of concrete using the bottom ash was lower than that of concrete using natural sand (BAO concrete). But by adjusting the amount of bottom ash in concrete according tab density so that the fine aggregate proportions change 44% to 38%, the compressive strength of concrete using the bottom ash could even be higher than BAO concrete. And the chloric content of concrete using the bottom ash increased as the replacement ratio of bottom ash increased, but it is satisfied with the chloric content of fresh concrete 0.30 kg/m2 below (concrete standard specification regulation value).
Fixed-Bed Column Study for Zn (II) Removal from Solution Using Expanding Rice Husk
Authors: Deng Zai Fang , Luo Xue Gang , Lin Xiao Yan
Published: August 2011

The performance of expanding rice husk (ERH) fixed bed column in removing Zn (II) from aqueous solution were studied in this work. Different column design parameters like bed height, flow rate and initial concentration were calculated. It was found that ERH was found to be an effective adsorbent for removal of Zn (II); and when conducted with Zn (II) concentration 12.8 mg L-1and flow rate 10 ml min-1with different bed depths such as 3, 6 and 9 cm, the equilibrium uptake was decreased from 5.181 to 4.33 mg g-1; the equilibrium uptake also decreased from 4.51 to 3.807 mg g-1with increasing of flow rate from 5 to 15 ml min-1and increased from 4.447 to 5.752 mg g-1when initial concentration increased from 12.8 to 35 mg L-1. The dynamics of adsorption process was modeled by bed depth service time (BDST), and indicating the validity of BDST model when applied to the continuous column studies.
Effect of MgO Coating on the Hydration Resistance of MgO-CaO Clinkers
Authors: Yin Hong Feng , Ma Yan Long , Yang Jun
Published: August 2011

To overcome the disadvantage of MgO-CaO refractories, as the poor hydration resistance, MgO coating on the MgO-CaO clinker was fabricated by carbothermal reduction MgO with carbon as reduction agent and then the oxidation of Mg vapor. Effect of processing parameters (such as carbon source, reaction temperature and holding time) on the hydration resistance of MgO-CaO clinkers were investigated by hydration resistance test and SEM. The results indicated that the hydration resistance of treated MgO-CaO clinkers was improved when carbon black was used as reduction agent due to easy reaction with MgO than the graphite and coke. The high reaction temperature among 1450~1600°C and prolonged holding time within 4 h resulted in improvement of the hydration resistance of treated MgO-CaO clinker. Deposition mechanism of MgO coating on the MgO-CaO clinker was discussed.
Microstructure and Magnetic Properties of Undercooled Fe-50at%Ni Alloys
Authors: Xie Hui , Bai G. H. , Jia Lei , Lu Zhen Lin , Kou Sheng Zhong
Published: August 2011

Bulk Fe-50at%Ni alloy melts were undercooled using cyclic superheating and glass slag purification. As a result, a maximum undercooling up to 217 K could be achieved. As-solidified microstructures were observed by means of optical microscope. Phase identification of Fe-50at%Ni alloys was performed using the Shimadzu X-ray diffractometer (XRD) system. The chemical constitution revealed using a JEOL Model JSM-6700F scanning electron microscope equipped with energy dispersive X-ray spectroscopy (EDX). The magnetic properties of the alloys were measured by vibrating sample magnetometer (VSM) with a DC M-H analyzer. The results indicated that there were twice grain refinements occurred within an undercooling range of 55-217K, where the first could be ascribed to dendrite-remelting, and the second to recrystallization. The phase composition of undercooled Fe-50at%Ni alloys comprised two phases, i.e., solid solution phases withbccandfccstructure. At various undercoolings, the saturation magnetizationMsandHcrelated closely to the measured grain sizeD, and they were in proportion toD-1by the regression analysis.
Fabrication and Cytotoxicity Studies of the TiO2 Doped with Copper-Based Nanocomposite Particles
Authors: Hung Chang Mao
Published: August 2011

Since the growing interest in the manufacture and environmental applications of nanocomposites consisting of CuO and TiO2nanoparticles (NPs), related toxicological effect and interaction with cellular structures for these newly developed materials are still unknown. Recent literature reveals that nanosized CuO and TiO2particles have cytotoxicity risks and ability to cause oxidative stress on health. This work considers the CuO doped TiO2nanocomposite particles were synthesized via a coprecipitation method with aqueous solutions as precursors of copper nitrateand titanium dioxide. Moreover, the nanocomposite particles were characterized using TGA-DTA, UV-Vis and TEM measurements. The calcination temperature was selected at 873 K. The nanocomposite particles were characterized by TEM, as the primary particles, aggregates ranged from 30 to 100 nm and have a good dispersion character. Cell cytotoxicity assessment and the percentage cell survival was determined by using 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenol)-2-(4-sulfophenyl)-2H-tetrazoli um (MTS) assay on human fetal lung tissue cell (MRC-5). The experimental results show that the CuO doped TiO2nanocomposite particles cause potential cytotoxicity effect in cultured human cells.
Effect of Oxide Additives on Catalysis and Microstructure of RBSN Using Low-Purity Silicon Powder as Raw Materials
Authors: Yang Wan Li , Shi Zhong Qi , Jin Zhi Hao , Qiao Guan Jun
Published: August 2011

The three kind of oxides such as 3Y-ZrO2, Fe2O3and MgO were used as catalyst in reaction bonded silicon nitride (RBSN) with low-purity silicon powder as raw materials. The oxides can strongly promoted the nitridation ratio of RBSN, and the catalysis effects of these oxides for RBSN were investigated. After 4h nitridation, the degree of nitridation increased from 43% to 96% by adding 10wt% of 3Y-ZrO2additive comparing with the sample without additive, and the catalystic effects of Fe2O3and MgO were slightly less than 3Y-ZrO2additive. XRD patterns revealed that the main phases of the reaction products were α-Si3N4, β-Si3N4and Si-N-O intermediation. SEM micrographs show that the hexagonal columnar β-Si3N4separated from acicular α-Si3N4.
Growth of Flower-Like AIN by Combustion Synthesis Assisted with Mechanical Activation
Authors: Shi Zhong Qi , Yang Wan Li , Qiao Guan Jun , Yang Jian Feng , Jin Zhi Hao
Published: August 2011

Flower-like AlN microstructure with many cone-like petals was prepared by combustion synthesis assisted with a mechanical activation (MA) method using NH4Cl as a reacting additive. The products were characterized by X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy dispersive spectrum (EDS) and transmission electron microscopy (TEM). A possible mechanism for the growth of AlN microflowers was proposed base on several parallel experiments and discussion. It was found that both the MA time and NH4Cl content play crucial roles for the growth of the flower-like microstructure.
Effect of Nickel Oxide Thin Films on Photoconversion Efficiency in Zinc Oxide Dye-Sensitized Solar Cells
Authors: Futemvong Surat , Pengpad Atip , Hongsith Niyom , Wongratanaphisan Duangmanee , Gardchareon Atcharawan , Choopun Supab
Published: August 2011

ZnO dye-sensitized solar cells (ZnO DSSCs) with different thickness of NiO thin films coated in photo-electrode and counter-electrode were investigated. NiO thin films were prepared by thermal evaporation of NiO onto FTO glass substrate. The films were characterized by FE-SEM. For the photo-electrode, NiO thin films were coated on ZnO with 0.2, 0.6, 1.1 and 2.2 mg to form a barrier layer. For the counter-electrode, NiO thin films were coated on FTO glass with 5.4, 10.8, 16.2 and 21.6 mg in order to increase a surface-to-volume ratio. The photoconversion efficiency of ZnO DSSCs was measured under illumination of stimulated sunlight obtained from solar simulator with the radiant power of 100 mW/cm2. It was found that ZnO DSSCs coated with 0.6 mg NiO in photo-electrode and 10.8 mg in counter-electrode exhibited the highest photoconversion efficiency of 1.00% and 0.92%, respectively. The enhancement of photoconversion efficiency with NiO coating maybe explained by decreasing of charge recombination in photo-electrode and increasing of active surface area in counter-electrode.
A Novel Antimicrobial Nano-Composite Porous Material for Bone Repair
Authors: Luo Pei Pei , Li Ji Dong , Zuo Yi , Wu Xia , Li Yu Bao
Published: August 2011

In this paper, isoniazid (INH)-loaded poly (ε-caprolactone) microspheres with a special microporous surface and relatively high drug loading were fabricated by an oil-in-oil (O/O) solvent evaporation method. Meanwhile the microspheres were produced by an oil-in-water (O/W) method for comparison. The technological parameters such as the concentration of surfactant, the volume of continuous phase and the quantity of the drug were investigated systematically. The microspheres morphology, their size distribution and the viscosity of both the dispersed and continuous phase were characterized. The results indicate that the O/O solvent evaporation method is a feasible approach to encapsulate micromolecular and hydrophilic drugs in PCL. This opens the door for INH-loaded microspheres able to release drugs and thereby improve the therapy of tuberculosis of bones and joints in the future.
Preparation, Electrochemical Properties and Cytotoxicity Assessment of Nanosized CuO/La2O3/CeO2 Composite for the Decomposition of Gaseous Ammonia
Authors: Hung Chang Mao
Published: August 2011

This work considers the CuO/La2O3/CeO2nano-rare earth composite materials were synthesized by coprecipitation method with aqueous solutions of copper nitrate, lanthanum nitrate and cerium nitrate. The performance of the selective catalytic oxidation of ammonia to N2(NH3-SCO) over a CuO/La2O3/CeO2nano-rare earth composite materials in a tubular fixed-bed reactor (TFBR) at temperatures from 423 to 673 K in the presence of oxygen was reported. The catalytic redox behaviors were determined by cyclic voltammetry (CV). Further, cell cytotoxicity and the percentage cell survival were determined by using MTS assay on human fetal lung tissue cell (MRC-5). The experimental results show that the CuO/La2O3/CeO2nanocomposite particles only minor cause cytotoxicity effect in cultured human cells.
The Synthesis of Magnetic Nano-Sized Iron Oxide from Liquid Solution by Adding Organic Components
Authors: Oybek Tursun Kulov , Park No Jin , Jo Soo Jeong , Lee Eun Young , Kamalov Sharo Futdin , He Li Li , Jeong Soon Wook , Kim Sung Jin
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.
Microstructure and Strength Properties of AZ31 Mg Alloy Foams
Authors: Zhao Rui , Kim Byeong Gu , Ryu Yong Mun , Hur Bo Young
Published: August 2011

It is difficult to control the pore size and distribution of Mg alloy foam by melt foaming method using titanium hydride as blowing agent and extraordinary coarse pore structures is often found in the Mg alloy foams. Using CaCO3 instead of titanium hydride as blowing agent, AZ31 Mg alloy foams with small well structure, porosity 35.0~72.0 % and average pore size 0.04~0.16 cm could successfully be fabricated In this study; AZ31 Mg alloy foam with the holding time of 30s had the best energy absorption. The energy absorption value of AZ31Mg foam was 5.52MJ/m3. After that, AZ31 foams sample was polished and rusted. The thickness cells were analyzed by use of Metallurgical Microscope and software. Then SEM micrograph of AZ31 Mg alloy foam and EDS analysis of the cell wall.
Anisotropic Tensile Deformation of Lotus-Type Porous Copper
Authors: Tane Masakazu , Okamoto Rika , Nakajima Hideo
Published: August 2011

The tensile deformation of lotus-type porous copper with cylindrical pores oriented in one direction was investigated. Deformation was occured homogeneously in the copper matrix for loadings parallel to the orientation direction of pores (pore direction), while deformation was localized in the matrix around pores for loadings perpendicular to the pore direction. In the case of parallel loading the decrease in cross section of tensile specimen was smaller than that of nonporous copper, because of the constant-volume law (i.e. incompressibility condition) for deformation was not applicable to the deformation of pores. In the case of perpendicular loading, the deformed regions were disconnected and constant-volume law holds only in the matrix around the pores, and thus, the cross section hardly decreases during the tensile deformation.
Micro-Porous Alumina Membrane Prepared by Dip Coating Using Latex Binder
Authors: Hemra Khanthima , Aungkavattana Pavadee , Atong Duangduen
Published: August 2011

Ceramic membrane has been extensively studied for a half of century. The research of alumina membranes was improved a great deal, however, they have always been considered as an opportunity in commercial product. In this research, submicron alumina powders, AKP-30 were deposited on the porous alumina tube support containing approximately 40% porosity by dip coating. The effects of solid loading, dispersant, and binder system on colloidal process were evaluated. It was found that the thickness of membrane layer depend on the type of binders (latex binder, polyvinyl alcohol binder, and poly (ethylene oxide) polymer binder) and dipping time when the withdrawal speed was constant. The proper suspension of 30 wt.% AKP-30 alumina powder with 18.8 wt.% latex binder provided proper sintered membrane without cracking or delaminating. The porosity and average pore size of coating layer was about 29% and 0.06 μm, respectively at a sintering temperature of 1400°C for 2 hr. The membrane layer was likely to thicken with increasing dipping time. The thickness of membrane after sintering was about 30-40 μm at a few second of dipping time.
Preparation of the Multi-Layer Copper and Nickel Foam by Electrodeposition
Authors: Zhang Qiu Li , Cheng Xuan , Lan Xin Zhe , Hu Xiao Yan
Published: August 2011

The multi-layer copper/nickel foam was prepared by the electrodeposition methods adopted the polyurethane as frame foundation. The foam is provided with a three-dimension grid structure and porosity of 96%-98%. The morphology of foam was examined by scanning electron microscope in synthesis procedure. The main physical characteristics of multi-layer copper/nickel foam were determined. Its apparent density and pore size are 190-210 kg/m3 and 1.4-1.7 mm respectively.
Fabrication of LaNiO3 Thin Film on the Si-Substrate by Sol-Gel Process
Authors: Liu Qian Li , Zhao Gao Yang , Zhao Gui Rong , Lei Li
Published: August 2011

Due to its perovskite crystal structure and good conductivity, LaNiO3(LNO) can be used as the electrode for piezoelectric and ferroelectric films. With the development of the silicon-based integrated ferroelectrics, preparation of LNO electrode film with good conductivity is of great importance for high-performance ferroelectric films. In this paper, LNO sol was prepared using the nickel acetate and the lanthanum nitrate as starting materials, with the acrylic acid as stablizer. Through the sol-gel process, LNO films with certain crystal orientation were prepared on silicon substrate. The film microstructure and electrical properties were analyzed. Results indicate that through proper sol component and heat treatment process, (100)-oriented, mirror-like LNO films with low surface resistance of 50 Ω/ can be obtained, which can be used as the electrode for the ferroelectric films.
Preparation of Fluorine Doped Tin Oxide Film by Ultrasonic Spray Pyrolysis
Authors: Ren Yang , Zhao Gao Yang , Shen Jie
Published: August 2011

Fluorine doped tin oxide (FTO) film is one of the most promising transparent conducting materials. It can be used for Low-E glasses, thin film solar cells, displays, etc. FTO film can be fabricated by various techniques. The technique of sol-gel combined with ultrasonic spray pyrolysis gives the possibility to produce high-quality large-scale FTO films. In this paper, the FTO sol is successfully prepared using pentahydrate stannic chloride (SnCl4•5H2O), hydrogen fluoride (HF) and methanol. Using the FTO sol, FTO films are prepared by ultrasonic spray pyrolysis technique. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM) are used to characterize the FTO films coated on glass substrates. Results indicate that the as-deposited films are polycrystalline SnO2 phase with tetragonal crystal structure, and that the average grain size for the samples is 160nm. The optical and electrical properties of the FTO film are also analyzed.
Synthesis of Nanosized TiO2-SiO2 Particles in Microemulsions Stabilized by Anionic Surfactants
Authors: Lee Man Sig , Lee Ju Dong , Kim Hong Dae , Hong Seong Soo
Published: August 2011

Nanosized TiO2-SiO2 particles were prepared by controlled hydrolysis of titanium tetraisopropoxide (TTIP) and tetraethylorthosilicate (TEOS) in microemulsions stabilized by anionic surfactants. Anionic surfactants ammonium carboxylate perfluoropolyether (PFPE-NH4) and sodium bis (2-ethylhexyl) sulfosuccinate (AOT) were used for formation of stabilized microemulsions in the W/C and W/O systems, respectively. The physical properties of the prepared particles have been investigated by TG-DTA, FT-IR, XRD and HRTEM. It is shown that the XRD pattern of the TiO2-SiO2 particles dried at 105 °C without calcination indicates amorphous. The particles calcined at 500 °C were identified as nanocrystalline anatase regardless of TTIP/TEOS molar ratio. The crystallite size of prepared particles decreased with increasing the silica content. From FT-IR analysis, the band for Ti-O-Si vibration was observed. The micrographs of HRTEM shown that the TiO2-SiO2 nanoparticles have a spherical morphology with a narrow size distribution and then the lattice fringe was 3.5 Å, which corresponds to the lattice spacing of (101) plane in the anatase phase.
Establishment of Waternode Stations for Water Quality Monitoring by IP-USN
Authors: Kwak Pill Jae , Kim Seog Ku , Yun Sang Leen , Kang Sung Won , Lee Hyun Dong , Lee Joo Yeon , Ban Hyo Jin , Yang Keun Ho , Oh Hee Jae , Kim Young Sung
Published: August 2011

Waternode station is a floating composite water quality monitoring device. The waternode station houses the multiple water quality measurement devices, control panel for wireless communication and solar cells for applying electric power. The floating devices are classified into general model with vertical dropping system and river model without vertical dropping system. The water quality measurement device measures pH, water temperature, conductivity, dissolved oxygen, turbidity and nitrate. And it measures all parameters simultaneously. The control panel is used for IP-USN system. USN (Ubiquitous Sensor Network) is a network system by water quality measurement devices. IP-USN is a USN system that identifies particular sensor connected to the internet. The data information is transferred by wireless modem based on TFB (Triple Frequency Band). Field application results showed that the waternode station is a reliable and cost-effective water quality monitoring solutions.
Nutrient Removal Using BauxsolTM for Treated Wastewater Reuse
Authors: Mun Jung Soo , Lee Sang Ho , Lee Jung Hun , Suh Jeong Yul , Kim Ree Ho
Published: August 2011

Urban areas consume huge amounts of water and produce much wastewater, which deteriorate the aquatic environment and exhaust the country’s freshwater resources. Water reuse from sewage and wastewater is recognized as a good option for securing water. There are several kinds of processes for improving the water quality. Nutrient removal is very important for water reuse, especially in water supply for outdoor use, to prevent water quality deterioration via eutrophication. Moreover, low cost and easy maintenance should be considered for nutrient removal. In this study, red mud and BauxsolTM, a mixed mineral powder made of physicochemically modified red mud residue generated by the Bayer process for alumina refineries, was used for the removal of nitrate and heavy metals in artificial solution, and of phosphate in final effluent, from a sewage treatment plant in Dae-gu, Republic of Korea. Nitrate removal by red mud showed little efficiency while heavy metal removal showed high efficiency. The concentrations of the total phosphate in the effluent and treated water were 1.51 and 0.14 mg/L, respectively, which represent about 90.7% removal. Before and after the treatment, the pH was maintained at a neutral range of 6.5-7.2. BauxsolTM also showed a high heavy metal removal capacity. Therefore, BauxsolTM in powder and pellet form can be applied individually or mixed with soil to improve water quality for water reuse.
Synthesis and Thermoelectric Properties of Undoped Half-Heusler Zr-Co-Sb Alloy Processed by Mechanically Alloying and Hot Pressing
Authors: Kim Il Ho , Kwon Joon Chul , Lee Young Geun , Ryu Sung Lim , Yoon Man Soon , Kim Whan Gi , Ur Soon Chul
Published: August 2011

Half-Heusler alloys are one of the potential thermoelectric materials for medium to high temperature range application. As a part of fundamental study to establish processing route and to observe thermoelectric properties in undoped state, ZrCoSb was selected, processed and evaluated. In an attempt to produce a half-Heusler thermoelectric materials having ultra fine grain structures, ZrCoSb was synthesized by mechanical alloying of stoichiometric elemental powder compositions, and consolidated by vacuum hot pressing. Phase transformations during mechanical alloying and hot consolidation were investigated using XRD, SEM and EDS. Single-phase, half-Heusler was successfully produced by vacuum hot pressing using as-milled powders without subsequent annealing. Thermoelectric properties as functions of temperature were evaluated in terms of Seebeek coefficient, electrical conductivity, thermal conductivity and the figure of merit for the hot pressed specimens. Mechanically alloyed half-Heusler phase, ZrCoSb, appeared to have a great potential as a thermoelectric materials in this study.