bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating PVC Degradation Using UV and Raman Spectroscopies
Authors: Al-Dossary Abdullah K. , Gilbert Marianne , Hitt David
Published: December 2009

While the world growth in PVC consumption continues (currently ~35 million tonnes per annum), its poor thermal stability, remains an issue due to restrictions on the use of stabilizers containing heavy metals such as lead. Monitoring degradation in PVC is important, and this work is concerned with the detection of PVC degradation using UV and Raman spectroscopies. The bands which appear in the Raman spectra of PVC samples after thermal degradation at around 1100 and 1500 cm-1, are the result of a resonance Raman effect.
Optimization of the PVC degradation assessment process using laser-Raman is crucial to minimize the effects of additive interference and the fluorescent background. The most important factor is the wavelength of the exciting laser source, as it should fall within the absorption range for polyene sequences in degraded PVC. Laser-Raman spectroscopy has been shown to be an appropriate method for the quantitative determination of the polyene length distribution in lightly degraded PVC samples.
The application of this method for various degraded PVC samples is reported. Ageing of compounds containing various heat stabilizers were considered, in order to assess their effectiveness. Additives studied included calcium zinc stabilizers and two commercial grades of hydrotalcite (Sorbacid 911 and Alcamizer P93).
Experimental Study on Property of Rubber Composites Filled With Carbon Nanotubes
Authors: Wang Ze Peng
Published: December 2009

The basic and dynamic mechanical properties and thrermal conductivity of rubber composites filled with carbon nanotubes (CNTs) and various particle-sized carbon blacks (CB) were investigated. Results indicated that tear strength and modulus at a definite elongation of rubber composites filled with CNTs were enhanced compared to the conventional CB filler. However, tensile strength and elongation at break became lower. Thermal conductivity of rubber composites partly filled with CNTs is higher than those filled with CB. Rubber filled with the combination of CNTs and the bigger CB particles was beneficial to improve wet-resistant performance and roll resistance of elastomer such as tire.
Two New Thermotropic Liquid Crystalline Polyesters and their Composites: Synthesis and Characterization
Authors: Zhang Chuan Ji , Huang Zhi Xiong , Shi Min Xian , Zhang Ming
Published: December 2009

Two new series of liquid crystalline polyesters were synthesized using melt polycondensation reaction.Glass fiber,as a reinforcement,was meltpolymerized with 4-acetoxybenzoic(ABA),4,4＇-diacetoxybiphenyl, isophthalic acid(IA) and terephthalic acid(TA) to make TLCP/GF composites with a good mechanical properties.All the obtained compounds were characterized by conventional spectroscopic methods. The structure of the target compounds and intermediates was conformed by the IR, 1H NMR and SEM. The thermal behavior of the polymers has been characterized using polarized optical microscopy and differential scanning calorimetry. The effect of monomer structure and mechanical properties has been investigated on the prepared polyesters. These compounds show a high birefringent Schlierene texture characteristic of the nematic phase on heating and cooling experiments. This was further confirmed using differential scanning calorimetric investigations.The melting points of polymers having a central 4,4’-biphenyldicarboxylate residue have broad endotherms. The glass transition temperature values of polyesters are not effect by the glass fiber.According to the SEM result showed that the composite had strong fiber-matrix adhesion.The effect of copolymerization with added glass fiber in synthesis process is compared with that of the anlogous homopolyesters by other processing mode.Our finding shows that the copolymers exhibit reduced technical process and maintained mechanical properties.
The Application of Harmonic Response Analysis in Different-Speed Mixer Design
Authors: Fan Zhi Min , Sun Wei Guang , Xu Jun
Published: December 2009

The different-speed mixer is used in the rubber industry widely. The dynamic response of different-speed mixer shaft is very key. Some displacement and dynamic stress response values of different-speed mixer shaft frequency are obtained by using the finite element method, which gives the basic theory for further systematic dynamic analysis and the structure design of different-speed mixer shaft.
Adsorption Properties of Chemical Crosslinked Polymer Gel
Authors: Hu Xiao Yu , Chen Ying Bo
Published: December 2009

Chemical crosslinker polymer gels were synthesized in situ polymerization of monomers in solvents with crosslinkers. Results showed that the solvent content of the polymer gels depended on the types of solvents and polymers as well as the crosslinkers. The adsorption ability to aromatic organic molecules of the polymer gels was measured by treating tryptophan solution containing phenol and pyrene aqueous solution. The aromatic compounds can be removed completely and no further pollution to the original solutions.
Development of Durable Softening and Water-Repellent PP/HDPE Heat-Bondable Composite Fiber
Authors: Sun Shi Yuan , Zhao Qing Fu , Xue Yuan
Published: December 2009

Spinning and finishing techniques of a durable softening and water-repellent PP/HDPE heat-bondable fiber were introduced. The fiber has a core-sheath structure. PP is the core and HDPE is the sheath. The core-sheath fiber structure and spinning materials properties make the fiber have a good heat-bonding performance. During the finishing process the fiber got a durable softening and water-repellent quality by the durable waterproofing agent—a mixture of PMHS and PDMS. Experiments show that the fibers begin to melt and bond each other at 127.5°C and could keep a good water-repellent performance after being washed five circles.
Visual Experiment Study on the Influence of Mold Structure Design on Injection Molding Product’s Defects
Authors: Xie Peng Cheng , Du Bin , Yan Zhi Yun , Ding Yu Mei , Yang Wei Min
Published: December 2009

Injection molding visualization is the experimental method of direct observation on the melt filling behavior in the mold cavity. By using developed visualization system, the influence of mold structure design on the injection molding product’s defects, such as jetting and weld were studied in this paper. The forming process of jetting was observed by the visual method, and results show that it is useful to avoid jetting by locating gate correctly. According to the generation of weld line in single gate cavity, an improved measure to adjust the weld locations by adding overflow traps was proposed. The result indicates that the overflow trap is good for adjusting weld location and makes the defects appear in the unimportant points of surface. Another experiment on the forming process of weld line in two-gate cavity with setting different distance parameters were carried out. The result shows that increasing of gates distance may significantly affect the performance of weld line.
Experimental Study on Manufacturing Process of Short Fiber-Rubber Composite Material Using New Type Six-Wing Synchronous Rotor
Authors: Zhang De Wei , Wang Chuan Sheng
Published: December 2009

A new type of six-wing synchronous rotor has been designed and manufactured for mixing requirements of the short fiber-rubber composite material. During the manufacturing process of the composite material, different addition proportions of the short fibers have been used. The physical and mechanical performances of the short fiber-rubber composite material have been investigated. The new type rotor meets the mixing requirements of the short fiber-rubber composite material, with the best addition proportion of the short fibers.
Research on Mechanical Performance of Roof Tiles Made of Tire Powder and Waste Plastic
Authors: Liu Yong , Yang Wei Min , Hao Ming Feng
Published: December 2009

The typical roof tiles made from soil or clay will be limited because it destroyed the farmland. On the other hand, the old tire and waste plastic increase year and year, which bring a serious environmental problem. So the roof tiles made from old tire and waste plastic will help a lot to decrease above environmental pressure. To get a suitable formula of roof tiles made from waste rubber tire powder and waste plastic, the present article studied mechanical performance of a series of composites. Then a preferred formula was got through comparing the mechanical performance.
Bioadhesive from Distiller's Dried Grains with Solubles
Authors: Fang C.Q. , Auras R. , Selke S.E.
Published: December 2009

Distiller's Dried Grains with Solubles (DDGS) is used to replace starch as a major feedstock material to produce bio-adhesive. The experimental conditions and the preparation process of the DDGS bioadhesive are outlined. The production and performance of DDGS adhesives were directly influenced by the heating temperature, heating time and concentration of hydroxide (NaOH) solution. When the heating temperature was 90 °C, the heating time was 10 min, and the concentration of NaOH solution was 30g/L, the yield of the DDGS adhesive was 61.6% wt/dry wt. The DDGS adhesive was less sensitivity to humidity than commercial starch adhesive.
Synthesis and Characterization of Novel Amphiphilic Fluorinated Triblock Copolymer
Authors: Tang Xin De , Han Nian Feng , Zhou De Jie
Published: December 2009

Atom transfer radical polymerization (ATRP) has been employed for the synthesis of a novel amphiphilic fluorinated triblock copolymer PEG-b-PS-b-PFHEM for anti-fouling coatings. The macroinitiator based on poly(ethylene oxide) monomethyl ether was used to prepare an amphiphilic diblock copolymer PEG-b-PSt-Br, which was then utilized to initiate the ATRP of fluorinated monomer perfluorohexylethyl acrylate (FHEA), resulting in an amphiphilic triblock copolymer. These copolymers were characterized by means of 1H NMR and GPC. The amphiphilic triblock copolymer surface composes of fluorinated and PEGylated blocks, and the fluorinated surface has critical surface energy, while the PEGylated surface is expected to have a relatively low interfacial energy when in contact with water. Microphase-separation of both blocks could take place and result in the reduction of protein adsorption and cell adhesion. The amphiphilic fluoropolymer has the potential application as excellent antifouling coatings and antifouling membranes.
Research on Microchannel of PMMA Microfluidic Chip under Various Injection Molding Parameters
Authors: Jiang Bing Yan , Liu Yao , Chu Chun Peng , Qiu Qing Jun
Published: December 2009

Microfluidic chip has bright application prospect in the field of chemical and biological analysis. PMMA is the best material for microfluidic chip fabrication because of its low cost, prominent electrochemical properties and biological compatibility. In this work, a triple-channel microfluidic chip was designed; a nickel mold insert with microstructure was fabricated by UV-LIGA technology, and then the injection mold was designed and fabricated. The change in cross-section dimensions of microchannel was chosen as evaluating indicator, and micro-injection molding experiments were carried out. Then the influence of process parameters on cross-section dimensions of microchannel was observed with microscope. Experiment results demonstrated that substrate and cover plate could be manufactured in a single injection molding process by "1+1" type mold, and the manufacturing cycle was reduced to less than 20s, so production efficiency was greatly enhanced. Best combination of process parameters was obtained when mold temperature was 80°C, melt temperature was 250°C and injection rate was 297mm/s. Thereby, high quality substrate and cover plate could be manufactured efficiently.
The Mechanical and it Combined with Enzymatic Preparation Methods of Microfibrillated Cellulose
Authors: Chen Wen Shuai , Yu Hai Peng , Liu Yi Xing , Li Qing
Published: December 2009

Microfibrillated cellulose (short for MFC) has rapidly advanced due to its unique nano-order-unit web-like network structure and such special properties as extremely high strength, large specific surface area and high aspect ratio. In the present paper, the processing technology and the research progress of the preparation methods of MFC with mechanical and it combined with enzymatic treatment are briefly reviewed, then the four main challenges about preparation of MFC are figured out. In the last section, the direction of this research field is also highlighted.
Influence of Fine Content of Carbon Black Pellets during Pneumatic Conveying on Rubber and Mixing Process
Authors: Li Yong
Published: December 2009

The impact of fine content of carbon black pellets on rubber mixing process and reasons for carbon black pellet degradation during pneumatic conveying process has been investigated and analyzed. The influential factors of carbon black degradation are introduced. It is identified and concluded that specific surface area of carbon black, size of carbon black pellets, parameters of pressure in conveying, conveying modes, materials of pipelines and conveying distance are major factors in the impact of degradation of carbon black. The conclusion is confirmed by the results of tests. The measures to reduce carbon black pellet fine content are proposed.
An Experimental Method for the In-Plane Deformation Measurement in a Sample of Transparent Polymeric Material
Authors: Li Xiao Lei , Liu Bo , Li Xiao Jing , Qie Yan Hui , Sang Jian Bing , Jia Hai Peng
Published: December 2009

With the increasing development of polymeric materials, it becomes important for research on mechanical properties of polymeric materials under large deformation conditions. To know displacement distributions in the polymeric structures could help us to better understand the deformation characteristics of polymeric structures in fracture analysis. In this paper, an experimental digital moiré method for the in-plane deformation measurement in a sample of transparent polymeric material, which is a non-contact method for full-field, large deformation and real-time measurement, is presented. The measurement principles and the basic procedures of the method are explained in detail. In order to demonstrate this method, a cross grating is generated and put into a transparent polymeric specimen. The subsequent fringe and displacement analysis is carried out using the method developed by the authors.
Impact on Tire Performance with Improvement of Semisteel Meridian Tire Lamination Processing
Authors: Wang Chuan Sheng , Fu Ping , Li Shan Hu , Jiang Yong Dian
Published: December 2009

The performances of tires which are affected by improving the building way for semisteel radial tire have been researched. The testing results show that there is a great effect on the tire’s uniformity and dynamic balance because the pressing ways of semi-steel radial tire bis two steps with two rollers lamination make the variation of tread size greater. When the lamination process of two steps with two rollers was changed into three steps with three rollers, the tire’s uniformity and the dynamic balance have been improved effectively, which significantly reduces the possibility of the change when the tread size becomes larger during the lamination of tread.
Structure and Properties of Chitosan Containing Polyacrylic Acid Hydrogel Grafted SMS Nonwovens
Authors: Zhuang Xu Pin , Deng Wen Jian , Cheng Bo Wen
Published: December 2009

Hydrogels donate moisture to dehydrated tissue and absorb some moisture and accepted in wound healing. Polypropylene (PP) SMS nonwovens were grafted polyacrylic acid (PAA) hydrogel technique contanining chitosan to enhance hydrophilicity and antibacterial activity. In the first stage, nonwovens were hydroxylated by treatment with aqueous potassium peroxydisulfate solution under a strong flow of nitrogen. In the second stage, the hydroxylated nonwovens were subjected to grafting of acrylic acid using cerric ammonium nitrate as an initiator. Subsequently, chitosan was grafted onto the modified NWs with N,N'-Methylenebisacrylamide. The modified nonwovens were characterized by XPS spectroscopy and SEM, the results showed that acrylic acid was copolymerized and hydrogel grafted onto SMS nonwovens. Hydrogel grafted nonwovens exhibited enhanced wettability and water absorption ability. With introduce of chitosan further, the modified NWs exhibited effectively antibacterial activity against E.coli.
The Steady-State Temperature Field Analysis of the 3D Rolling Tire Based on Adina FEA Software
Authors: Li Jing , He Yan , Chen Zhen Chao
Published: December 2009

Based on the Adina finite element analysis software, 3D axisymmetric finite element analysis model of the 205/75R15 PCR tire was established, the steady temperature field of rolling tire was simulated, and the thermal distribution colored cloud diagram of steady-state temperature field of 3D rolling tire which directly shows the temperature distribution of each section of tire was analyzed to offer certain guidance to the improvement of tire structure and rubber formula.
Research on High-Powered Brazing Diamond Saw for Cutting Vehicle Tyre
Authors: Ma Bo Jiang , Xu Zhu Ang
Published: December 2009

The high-powered brazing diamond saw was developed to cut vehicle tyre efficiently. The Ti-coated diamond and the uncoated diamond were brazed with NiCr alloy by high-frequency induction under argon atmosphere at 1020°C within 10 seconds. The interfacial microstructures between brazed diamond and the filler alloy were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersion spectrometer (EDS). It is surprisedly found that Cr-carbides forms compactly and normally on the surface of Ti-coated diamond brazed, whereas Cr-carbide forms loosely and tangentially on the surface of uncoated diamond brazed. The abrade experiment results for the brazed diamonds show that the bond strength between the Cr-carbide and uncoated diamond brazed is lower than the normally formed Cr-carbide and the diamond. Furthermore, the cause that Ti changes the morphology of Cr-carbides on the surface of Ti-coated diamond brazed is discussed by the further tests that are specially designed.
Research on the Polymer Ultrasonic Plastification
Authors: Jiang Bing Yan , Hu Jian Liang , Wu Wang Qing , Pan Shu Ye
Published: December 2009

Melt flow properties in micro cavity play an important role in the micro injection molding (MIM). Based on the point view of improving the melting plastification quality, this study focus on solving the problem of melt filling difficulty in micro cavity of MIM by introducing the ultrasonic vibration field into the polymer plastification process. This paper studied the polymer’s ultrasonic plasitfication process by Theoretical analysis and Polymer ultrasonic plastification experiment.
Predicting Diffusion Coefficients from First Principles via Eyring’s Reaction Rate Theory
Authors: Mantina Manjeera , Chen Long Qing , Liu Zi Kui
Published: December 2009

A simplified approach to predicting diffusion coefficients directly from first-principles is proposed. In this approach, the atomic jump frequencies are calculated through the Eyring’s reaction rate theory while the temperature dependence of diffusion coefficients are accounted using phonon theory within the quasi-harmonic approximation. The procedure can be applied to both self-diffusion and impurity diffusion coefficients and different crystal systems. Applications to self-diffusion coefficients in fcc Cu, bcc Mo, hcp Mg and impurity diffusion coefficients of Li in fcc Al, W in bcc Mo and Cd in hcp Mg show agreement with experimental measurements.
Gouge Assessment for Pipes and Associated Transferability Problem
Authors: Hadj Meliani Mohammed , Pluvinage G. , Capelle J.
Published: December 2009

The purpose of this work is to assess a gouge defect in a pipe submitted to internal pressure. To do that a method is used which is based upon a failure assessment diagram and, more precisely, upon a Modified Notch Failure Assessment Diagram (NMFAD) which has been proposed as a mesofracture approach. The safety factor has been determined under conservative conditions; i.e for a X52 pipe steel having a relatively low fracture toughness and a severe gouge defect with high aspect ratio and high constraint. In addition, a mesofracture approach to the fracture toughness transferability problem has been proposed. The crack (K-T) methodology has been modifed to create the ( –Teff) two-parameter fracture resistance criterion.
Elastic-Plastic Fracture Mechanics Model for Planar Isotropic Porous Materials with Small Mixed-Mode Cracks
Authors: Liao K.C.
Published: December 2009

A porous panel with a small crack subjected to mixed-mode loads under yielding and plane stress conditions is examined here. The recently proposed modified Gurson’s yield criterion is adopted to account for the non-linear behavior of a porous panel with normal anisotropy but planar isotropy. Trends in the constant J contour, based upon a finite element analysis, are correlated with those of constant fatigue life contours under mixed-mode I and II loading conditions. The effects of both the anisotropy parameter and the porosity upon the J integral are then demonstrated. Simulation results show that the transverse strain dominates constant J contours on the -plane as the anisotropy parameter increases under the mixed-mode loads. However, constant J contours are less sensitive to the transverse strain even if a relatively larger void volume fraction appears in the panel.
Strengthening of Dense Bioceramic Samples Using Bioresorbable Polymers – A Statistical Approach
Authors: Dorozhkin Sergey V. , Ajaal T.
Published: December 2009

Mechanical properties of bioceramics are poor and need to be improved for biomedical applications. In order to do this, bioceramics may be strengthened by bioresorbable polymers. In this study, the mechanical properties of poly(ε-caprolactone), PCL, coated dense bioceramic pellets made of silica-contained calcium phosphates were studied and analyzed using a statistical experimental design in conjunction with Taguchi methods for optimization. The aim of this experimental work was to maximize the pellet flexural strength and minimize the amount of deposited PCL. The most important factors affecting the strengthening of the ceramic pellets were evaluated. Four independent processing variables (a removal technique of an excess polymer solution, concentration of PCL in the solution, a heat treatment temperature and the number of dipping) with three levels of variability were tested using an L9 (34) orthogonal array. A statistical experimental design using the analysis of means and orthogonal array was applied to optimize the responses of these variables. The optimal conditions for achieving the maximal flexural strength of the coated pellets at the minimal amount of the deposited PCL were determined. A high quality dense bioceramic pellets with ~ 10.5 MPa flexural strength and ~ 80 μm thickness (~ 21 mg weight) of the deposited PCL coating were manufactured as a result.
Ferroelectric Properties of Epitaxial BiFe0.97Mn0.03O3 Thin Films with Different Crystal Orientations Deposited on Buffered Si Substrates
Authors: Go Hyun Young , Wakiya Naoki , Kiguchi Takanori , Yoshioka Tomohiko , Sakurai Osamu , Cross Jeffrey S. , Tanaka M. , Shinozaki Kazuo
Published: December 2009

We investigated electrical properties of epitaxial Mn doped bismuth ferrite BiFe0.97Mn0.03O3 (BFMO) thin films with different crystal orientations deposited on Si substrates with appropriate buffer layers. Epitaxial SrRuO3 (SRO) thin films with (001), (101), and (111) orientations were grown on CeO2/yttria-stabilized zirconia (YSZ)/Si(001) substrates and YSZ/Si(001), respectively, by the insertion of MgO and TiO2 atomic layers using pulsed-laser deposition (PLD). Using spin coating, we deposited BFMO thin films onto orientated SRO thin films. The BFMO orientation followed the SRO orientation. The Pr values of the BFMO were ordered as follows {111}>{110}>{100}, which is the same as that predicted by crystallographic considerations. The largest Pr value of the {111} orientation is 76 μC/cm2 at 100 kHz, 25°C.
Preparation of (Ba1-x, Srx)TiO3 Thin Films on Glazed Alumina Substrate and Improvement of Temperature Dependence of Dielectric Properties
Authors: Nozaka Takashi , Mizutani Yoji , Bhakdisongkhram Gun , Kawakami Yuta , Echizen Masahiro , Nishida Takashi , Takeda Hiroaki , Uchiyama Kiyoshi , Shiosaki Tadashi
Published: December 2009

In this study, (Ba1-x,Srx)TiO3 thin films of various composition ratios were deposited on glazed Al2O3 substrates by the CSD method, and the temperature dependence of the dielectric property was analyzed. The dielectric property of the BST (80/20) thin film annealed at C was highly tunable, and the temperature dependence of the dielectric constant was stabilized at around room temperature. However, this BST (80/20) thin film exhibited intense ferroelectricity. Its tan intensified to 0.0511 in the high-frequency range (1 MHz). After the BST thin film was annealed at 600C, the grain size of the BST thin film was reduced to 40 nm and the ferroelectricity was alleviated. The dielectric constant, tan, and tunability of the BST thin film at 100 kHz were 158, 0.0170, and 39.6 (214 kV/cm, 6.0 V), respectively. The change rate of the dielectric constant, which indicates its temperature dependence, was ±7 or less in the range of -55 to 85C. Therefore, this BST thin film was considered to guarantee a wide operation temperature range for microwave tunable devices.
Structural Characteristics and Ferroelectric Properties of Bismuth-Based Compound Thin Films Crystallized by Hot Isostatic Pressing
Authors: Kobune Masafumi , Tada Hideto , Oshima Hisashi , Horii Daisuke , Tamura Akihiro , Daiko Yusuke , Mineshige Atsushi , Yazawa Tetsuo
Published: December 2009

After depositing amorphous (Bi0.5La0.5)(Ni0.5Ti0.5)O3 (BLNT) films on BLNT seed layer/Pt(100)/ MgO(100) substrates by room-temperature sputtering, the crystallization of the perovskite-struc- tured films has been tried by hot isostatic pressing (HIP). The samples with a single-phase perovskite structure HIP-treated at 800°C for 1 h under gas pressures of 0.51.0 MPa showed good crystallinity of  = 0.960.98 without accompanying the precipitation of the secondary phase. It was confirmed that a large root mean square roughness value of 44.2 nm for the sample HIP-treated at 800°C for 1 h under gas pressure of 0.1 MPa is due to innumerable Bi4Ti3O12-like rod-shaped grains precipitated in the film surface, based on atomic force microscopy. It is shown that the BLNT sample HIP-treated at 800°C for 1 h under gas pressure of 1.0 MPa exhibits the best hysteresis loop shape with a remanent polarization of Pr = 5 C/cm2 and a coercive field of Ec = 150 kV/cm of the six.
Effects of Pretreatments on Deposition Rate of Films in Aerosol Deposition Method
Authors: Mihara Kensuke , Hoshina Takuya , Kakemoto Hirofumi , Takeda Hiroaki , Tsurumi Takaaki
Published: December 2009

In the aerosol deposition method (ADM), we investigated an influence of pre-treatments for barium titanate powders as raw material on the deposition rate of thick films. By sieving and drying the powder, deposition rate of the films fabricated by ADM was effectively enhanced. On the other hand, heating the powders at 400-800°C, the resulting powders caused low deposition rate of the films. When a planetary milling was performed prior to charge aerosol chamber, the deposition rate of the films was four times higher than that in deposition using the powder without milling. By changing the milling rotation rate, we control size of agglomerated particles consisting of powders, which results in the control of deposition rate of the films.
Radiation of X-Rays in Low-Pressure Gas Using LiNbO3 Single Crystal
Authors: Fukao Shinji , Nakanishi Yoshikazu , Mizoguchi Tadahiro , Ito Yoshiaki , Yoshikado Shinzo
Published: December 2009

The gas pressure and the types of ambient gas dependence of X-ray intensity were investigated for LiNbO3 single crystals polarized in the c-axis direction at pressures of approximately 1 to 30 Pa. The integrated X-ray intensity showed a local maximum value at the pressure Pmax. Pmax moved to the high-pressure side in the ambient with a large first ionization energy. Pmax was proportional to the Boltzmann factor using the first ionization energy of each ambient gas molecule. The X-ray intensity was approximated using the quadratic function, which was convex upward for the pressure. It was found that one of the causes of the decrease in X-ray intensity on the pressure side higher than Pmax was the adsorption of positive ions on the crystal electric surface.
Dielectric and Magnetic Properties of CoFe2O4-BaTiO3 Composite Thick Film
Authors: Zhang Ling , Zhai Ji Wei , Mo Wei Feng , Yao Xi
Published: December 2009

(x)CoFe2O4-(1-x) BaTiO3 thick film with x=0.2 was prepared by electrophoretic deposition technique using BaTiO3 and CoFe2O4 nanopowders. X-ray diffraction indicated the film was consisted of single spinel CoFe2O4 and perovskite BaTiO3 phase. The thick film exhibited good ferromagnetic and ferroelectric property. The dielectric properties were influenced by ferromagnetic phase, especially at low frequency and high temperature, which was attributed to space charge effects and Maxwell-Wagner relaxation.
Acceptor-Doped Ferroelectric Modeling via Monte Carlo Simulation
Authors: Sucharitakul Sukrit , Yimnirun Rattikorn , Laosiritaworn Yongyut
Published: December 2009

A 2D Monte Carlo simulation was done as an approach to get further insight of acceptor-doped ferroelectric material. By utilizing vector model allowing 14 directions of orientation for ferroelectric systems, Metropolis algorithm was applied on DIFFOUR Hamiltonian to obtain hysteresis profiles. Subjected to different concentration of acceptor dopants, power law scaling of hysteresis properties were obtained as functions of external parameters such as temperature, external field amplitude and frequency. The hysteresis loop shape and properties agreed well with those obtained experimentally.
The Effect of Calcination Temperatures on the Phase Formation and Microstructure of (Pb1-xSrx)TiO3 Powders
Authors: Sumang R. , Bongkarn Theerachai
Published: December 2009

(Pb1-xSrx)TiO3 (PST) (x=0.25, 0.50) powders were synthesized by a mixed oxide solid-state reaction method under various calcination temperatures (600-1100oC). Powder samples were characterized using thermogravimetric (TGA), differential thermal analysis (DTA), x–ray diffractrometer (XRD) and scanning electron microscopy (SEM). The results showed that a single-phase of PST for x=0.25 and 0.50 powders was successfully obtained with a calcination condition of 950 oC for 2 h with a heating/cooling rate of 5oC/min. The TGA-DTA results corresponded to the XRD investigation. The lattice parameter a increased whilst the lattice parameter c decreased with increasing calcination temperatures. The tetragonality of powders decreased with an increase of calcination temperatures. The average particle size of the powders increased with the increase of calcination temperature.
Influences of Firing Temperatures on Phase and Morphology Evolution of (Ba0.25Sr0.75)(Zr0.75Ti0.25)O3 Ceramics Synthesized via Solid-State Reaction Method
Authors: Thongtha Atthakorn , Angsukased Kritsana , Bongkarn Theerachai
Published: December 2009

The effect of calcination (1000-1400 oC) and sintering temperatures (1400-1600 oC) on the phase formation and microstructure of barium strontium zirconate titanate [(Ba0.25Sr0.75)(Zr0.75Ti0.25)O3; BSZT] ceramics were investigated. BSZT powders were prepared by the solid-state reaction method. Higher calcination temperatures increased the percentage of the perovskite phase, but decreased the lattice parameter a of BSZT powders. The pure perovskite phase of BSZT powders was detected above the calcination temperature of 1350 oC. The microstructure of BSZT powders exhibited an almost-spherical morphology and had a porous agglomerated form. The average particle size and the average grain size of the ceramics were increased with the increase of calcination and sintering temperatures. The highest density of the samples was 5.42 g/cm3 which was obtained from ceramic sintered at 1550 oC for 2 h.
Preparation and Characterization of Lead Free Multi-Layer Ceramic Actuators with Ni Inner Electrodes Prepared by Inkjet Printing
Authors: Sakai Yuichi , Futakuchi Tomoaki , Adachi Masatoshi
Published: December 2009

In order to prepare lead free multi-layer ceramic (MLC) actuators with Ni inner electrodes, inkjet ink containing NiO was prepared and its rheological properties were examined. The viscosity of the ink followed the Andrade's equation. By using this ink, Ba(Ti,Zr)O3 based MLCs were prepared. The printed NiO layers were reduced to metal Ni and they functioned as the inner electrodes. The remanent polarization of the MLCs increased with the grain growth caused by the increase of firing temperature. The remanent polarization Pr and coercive field Ec of the MLCs fired at 1400°C were 6.4 μC/cm2 and 3.5 kV/cm, respectively. The displacement of the MLCs with 7 active layers was approximately 320nm at 30 kV/cm. The effective d33 shows approximately 160 pm/V when the electric field was 10 kV/cm.
E–J Characteristics in Multilayer Ceramic Capacitors with the Thin Dielectric Layers
Authors: Nakano Makito , Saito Akira , Wada Nobuyuki
Published: December 2009

The factors causing a decrease in the resistivity of multilayer ceramic capacitors (MLCCs) with a decrease in the thickness of dielectric layers were examined by carrying out measurements and finite element method (FEM) simulations. The obtained electric field vs. current density plots (E–J characteristics) indicated that the local concentration of electric field increased with the decrease in the thickness of the dielectric layers. The investigation of the local concentration of electric field at the grain boundaries using an FEM showed that the decrease in resistivity was caused by the roughness of the interface between dielectric layers and inner electrodes and the presence of large grains in the dielectric layers.
Electrical Properties of Conductive Paste with Silver Nanoparticles and its Application to Flexible Substrates
Authors: Yamamoto Yukio , Ogihara Takashi
Published: December 2009

Silver nanoparticles produced with a solid-phase thermal decomposition method were used for the preparation of a conductive paste supporting curing at low temperatures. The conducting paste was prepared by blending fine spherical silver powder and silver nanoparticles with a diameter of 20nm in order to reduce the electric resistivity of the electrodes. Although the viscosity of the conducting paste increased by about 25% after 60 days, it exhibited superior stability to dispersion in comparison to commercial paste. The electric resistivity of the electrode was of the order of 10-6Ωcm at a curing temperature of 200°C. Using this conducting paste, it is possible to print at widths of 20m. The resistivity was further reduced by 1% in the high temperature test at 120°C, by 5% in the high humidity and high temperature test, and by 5% during the thermal shock test at temperatures ranging from -45 to 80°C.
Growth and Characterization of Bismuth Magnesium Titanate Bi(Mg1/2Ti1/2)O3
Authors: Yoneda Yasuhiro , Saitoh Hiroyuki , Yoshii Kenji , Nishida Takashi , Hayakawa Hironori , Ikeda Naoshi
Published: December 2009

A new oxide, Bi(Mg1/2Ti1/2)O3 was prepared using a high-pressure high-temperature technique at 8 GPa and 1000°C. As-sintered Bi(Mg1/2Ti1/2)O3 has the BiFeO3-type perovskite structure with the rhombohedral R3c. After ground, crystal structure changed to tetragonal P4mm. Structure parameters of tetragonal Bi(Mg1/2Ti1/2)O3 were refined from laboratory X-ray powder diffraction data (a = 4.033(10) Å, and c = 3.938(10) Å). Bi(Mg1/2Ti1/2)O3 does not decompress at ambient pressure, but the structure changed from rhombohedral to tetragonal on heating above 800°C. This phase transition was nonreversible. Bi(Mg1/2Ti1/2)O3 is expected to be one of the end members of lead-free ferroelectric materials.
Application of Nano-Sized CeO2 Powder for Fast Response Oxygen Sensors
Authors: Murayama Norimitsu , Izu Noriya , Shin Woosuck , Matsubara Ichiro
Published: December 2009

For resistive oxygen sensor elements of Ce1-xZrxO2 (x = 0.0, 0.05, 0.1, 0.2), grain diameter was varied in the range of 86 – 300 nm by changing sintering temperature or changing Zr content. The grain diameter decreased with increasing Zr content. The response time was approximately proportional to the square of the grain diameter. In the relationship between the amplitude of sensor output, An and the frequency, f of sine wave of variation in oxygen partial pressure, the gradient in the high-frequency region of a plot of log An vs. log f in was approximately –0.5. From these results, it was concluded that the sensor response was determined by the oxygen vacancy diffusion rate. The grain diameter of Ce0.8Zr0.2O2 element was 86 nm and the response time at 1073 K was 9 ms, which result opens the door to the technological development of independent control of engine cylinders.
Ultra-Rapid CO Gas Detection by a Gas Sensor Based on Flame-Spray-Made Pt/ZnO Nanoparticles
Authors: Tamaekong Nittaya , Liewhiran Chaikarn , Wisitsoraat Anurat , Phanichphant Sukon
Published: December 2009

ZnO nanoparticles doped with 0.2-2 at.%Pt were successfully produced in a single step by flame spray pyrolysis (FSP) technique using zinc naphthenate and platinum (II) acetylacetonate dissolved in xylene. The particle properties were analyzed by XRD, BET and TEM. Depending on FSP conditions, ZnO nanoparticles and nanorods were observed. The crystallite sizes of ZnO spheroidal particles were found to be ranging from 5 to 20 nm, while ZnO nanorods were seen to be 5-20 nm in width and 20-40 nm in length. ZnO sensing films were prepared using Al2O3 substrate interdigitated with Au electrodes by spin-coating technique. The gas sensing properties toward carbon monoxide (CO) was studied at the operating temperatures ranging from 200 to 350°C. It was found that the 0.2 at.%Pt/ZnO sensing film showed the highest sensitivity and the fastest response time at 350°C.
Photo-Assisted VOC Detection by Transparent pn Junction
Authors: Nakamura Yoshinobu , Morita Yusuke , Yoshida Yasuhiro , Fujitsu Satoru
Published: December 2009

The p-NiO/n-ZnO transparent pn heterojunction is prepared by RF magnetron sputtering technique and processed into a chemical sensor element by photolithography pattering and chemical etching process. Forward biased p-NiO/n-ZnO heterojunction sensor can detect VOCs at room temperature and its gas sensitivity is extremely enhanced with the assist of deep UV light incidence. Even if the testing gas is thermodynamically stable such as aromatic VOC, the p-NiO/n-ZnO heterojunction sensor can detect it with the concert mechanism involving “electric” and “photo” assistance.
Electrical Properties of Dye-Sensitized Solar Cells Prepared by Blending SnO2 Micro Particles and TiO2 Nano Particles
Authors: Nakamura Takahiro , Nakatani Yoshihiro , Ogihara Takashi , Horikawa Hajime , Asahara Masahiro
Published: December 2009

Conductive SnO2 powder was synthesized by ultrasonic spray pyrolysis and was blended with TiO2 nano particles in order to improve the conductivity of TiO2 porous films used in dye-sensitized solar cells. However, the conductivity of the films decreased because of the exposure of SnO2 to high temperature during synthesis and calcination.
Improvement of Electromechanical Coupling Factor and Mechanical Quality Factor in PZT-PMN Ceramics by MnO2 Addition
Authors: Tipakontitikul Rungnapa , Kamonlert Amporn , Eitssayeam Sukum , Niyompan Anuson
Published: December 2009

PZT-PMN ceramic system with presence of MnO2 contents were proposed and prepared using conventional sintering method as for piezoelectric transformer application. Phase formation and several dielectric and piezoelectric parameters were studied as a function of MnO2 concentration. The x-ray diffraction study revealed the tetragonal symmetry for all samples with MnO2 doping. To determine polarization, the P-E hysteresis loop were produced and the results indicated that entering of Mn4+ ions in the ceramic structure created large amount of oxygen vacancies and the consequent was observed as displacement of the loops to E axis. The obtained optimum parameter are d33 = 119 pC/N, kp = 0.207, Qm = 1669, tan = 0.0101, Pr = 20 μm/cm2 and Ec = 10 kV/cm.
Electrocatalytic Activities of Trirutiles Based on MTaO6 (M=Co, Ni, Mg) for Oxygen Reduction Reaction
Authors: Konishi Takayuki , Kawai Hideki , Saito Morihiro , Kuwano Jun , Shiroishi Hidenobu
Published: December 2009

The trirutile oxides MTa2O6 (M=Co,Ni,Mg) [MTs] and the substitution products M1-xNxTa2-yLyO6 (N=Mn, L=Sn,Ti,Zr) [M1-xNxTa2-yLy] were prepared by a conventional solid-state reaction. The oxygen reduction reaction (ORR) activities were evaluated with the onset potentials (Eon) of the ORR currents, the disk current densities (iD) and the efficiencies (Eff4) of 4-electron reduction, measured by a rotating ring-disk electrode (RRDE) technique. All the samples showed ORR activities and the Eon values were around +0.8 V vs. RHE in 0.1 M KOH. The CoTa2O6 electrocatalyst showed the best ORR property of the MTs samples: its Eff4 value was as high as ~80%. With substitution of Ti or Sn, the ORR activities of MgTa1.9T0.1O6, CoTa1.8Sn0.2O6 and NiTa1.9Ti0.1O6 were improved in alkaline solution, compared with those of MTa2O6. In acid solution, the same substitution of Ti and Sn resulted in improvement of Eff4, but no significant improvements of Eon and iD.
Effect of Thermal Annealing on Electrical Degradation Characteristics of Sb2O3-Bi-Mn-Co-Doped ZnO Varistors
Authors: Takada Masayuki , Sato Yuuki , Yoshikado Shinzo
Published: December 2009

The effects of thermal annealing on the electrical degradation of Sb2O3-Bi-Mn-Co-doped ZnO varistors were investigated. For samples with 0.04 mol% Sb2O3 or more, the nonlinearity index  of the voltage-current (V-I) characteristics after electrical degradation increased upon annealing. More-over, the value of  after electrical degradation was proportional to the full width at half maximum (FWHM) of the X-ray diffraction peak for Zn2.33Sb0.67O4-type spinel particles under various annealing conditions. The added Sb2O3 did not dissolve in the ZnO grains but became segregated at grain boundaries. Therefore, it is speculated that the increase in the FWHM of the spinel particles is due to an increase in the numbers of fine spinel particles at grain boundaries and triple points during annealing. Furthermore, it is suggested that the improvement in the electrical degradation upon annealing is due to a decrease in the mobility of oxide ions or Zn2+ ions owing to their being blocked by uniformly distributed fine spinel particles at grain boundaries.
Thermophysical Behaviour of Crystalline Halides with Temperature
Authors: Anis-ur-Rehman M.
Published: December 2009

The thermal conductivity, thermal diffusivity and volumetric heat capacity of monocrystalline AgCl and AgBr were measured simultaneously, by Advantageous Transient Plane Source method in the temperature range 77-350 K. Both thermal conductivity and thermal diffusivity follow Eucken’s law in the temperature region studied. The heat capacity at constant pressure (CP) determined from the volumetric heat capacity agrees with the calculated one at room temperature. The values of CP obtained from this experiment along with the reported data as a function of temperature are also reported. The ratio of the thermal conductivity (λ) of AgBr and AgCl calculated from the Leibfried-Schlömann (LS) formula are in excellent agreement with the ratio measured experimentally. The dielectric constant and loss factor, of these crystalline hallides, are also reported as a function of frequency in the range 100 Hz to 1 MHz at room temperature.
Photocatalytic Activity of Bismuth Layered Perovskite Treated with Acid
Authors: Watanabe Soihiro , Narumi Yousuke , Toda Kenji , Ishigaki Tadashi , Uematsu Kazuyoshi , Sato Mineo
Published: December 2009

We synthesized Sr0.7La0.2[ ]0.1Bi2Ta2O9 (SBTL , [ ] vacancy), and measured their photocatalytic activity for water decomposition under UV light irradiation after acid treatment. They showed the high photocatalytic activity under UV light irradiation (H2 evolution (213μmol / h) , O2 evolution (82μmol / h)).
Sliding Wear Behavior of a Duplex Stainless Steel
Authors: Mestra Alvaro , Fargas Gemma , Anglada Marc , Mateo Antonio
Published: December 2009

Duplex stainless steels contain similar amounts of austenite  and ferrite α. This two-phase microstructure leads to an excellent combination of mechanical properties and corrosion resistance. However, there are few works dealing with the wear behaviour of these steels. This paper aims to determine the sliding wear mechanisms of a duplex stainless steel type 2205. In order to do it, three different sliding velocities (0.2, 0.7 and 1.2 m/s) and six sliding distances (500, 1000, 2000, 3000, 4000 and 5000 m) were selected. The results show that wear rate depends on both sliding velocity and sliding distance. The wear mechanisms detected were plowing, microcracking and microcutting (typical mechanisms of fatigue wear). These mechanisms evolve according to sliding velocity and sliding distance, highlighting a transition zone in which wear rate is reduced.
Hall-Petch Relationship of a TWIP Steel
Authors: de las Cuevas F. , Reis Mónica , Ferraiuolo A. , Pratolongo G. , Karjalainen L. Pentti , Alkorta Jon , Gil Sevillano J.
Published: December 2009

The grain size dependence of the tensile properties of a TWIP steel has been determined for a wide range of grain sizes obtained by grain growth after complete recrystallization of cold rolled material. The near-linear stress-strain behaviour typical of either TWIP steels or other materials that deform by twinning has been observed, the work hardening rate being larger for the smaller grain sizes. The Hall-Petch slope increases as a function of strain, from 350 MPa μm1/2 for the yield stress to 630 MPa μm1/2 for the maximum uniform strain in the tensile tests, ε  0.40. Profuse twinning is observed in deformed specimens by means of FIB-ISE.
Simulation of the Co-Extrusion of Hybrid Mg/Al Profiles
Authors: Muehlhause Jerome , Gall Sven , Müller Sören
Published: December 2009

Extrusion of composite materials can offer big advantages. In this work the manufacturing of a hybrid metal profile in a single production step was investigated. A porthole die was used, thus producing profiles with extrusion seams. Along the seams a material mix up was visible. The extrusion process was simulated with the Finite Element Method to investigate the material flow in die and welding chamber in order to understand the cause for the defects at the seams.
Analysis of Metal Flow of Aluminum through Long Choked Die Channels
Authors: Valberg Henry Sigvart
Published: December 2009

The mechanics of metal flow through long choked die channels have been investigated in unlubricated hot aluminum extrusion. Experiments were performed in a laboratory press at an earlier occasion by letting a grid pattern introduced into the billet flow down into the choked die channel to appear adjacent to the channel wall. The grid pattern was then revealed to characterize the metal flow in the channel. A 2D-model of the extrusion process was made. The model was applied to study the conditions in the extrusion experiments and in this model good similarity was obtained with the experiment. New knowledge regarding the metal flow through a choked die channel have been obtained this way, such as; contact conditions, presence of sticking and sliding zones, friction conditions in the sliding contact zone and the velocity profile over the cross-section of the channel.