bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Stress Intensity Factor and Crack Propagation for Alloy X-750 Pressure Vessel with a Blunting Crack
Authors: Mahdavi Ehsan , Mashhadi Mahmoud Mosavi , Amidpour M.
Published: July 2010

It is well known that the crack growth rate fatigue and stress corrosion cracking can be approximated by a power function of the stress intensity factor. In this study, stress intensity factor for elliptical crack under the uniform tension in linear elastic fracture mechanics (LEFM) is investigated therefore for this purpose, a pressure vessel modeled by finite element. A crack modeled on the pressure vessel and then the stress intensity factor for crack propagation in different methods is evaluated. Finite element analysis calculates stress intensity factor in the values of the J-integral are based on the stress intensity factors, JK, and by evaluating the contour integral directly, JA. The stability of crack growth is considered so the ductile crack extension is determined by pursuing the equilibrium between loading and crack resistance. Using especial method of meshing caused to have accurate results. This method causes to decrease run time and considerable accuracy. Then stress intensity factor is calculated for different position of the crack such as crack front and then compared to each other.
Phase and Structure Formation of Metallic Materials Electrodeposited via a Liquid State Stage: New Experimental Proof
Authors: Girin Oleg
Published: July 2010

On the basis of the discovered phenomenon of phase and structure formation of metallic materials being electrodeposited through a stage of liquid state it was predicted and experimentally proved the following: a) formation of intermediate phases in the form of intermetallides in electrodeposited metallic alloys during the electrochemical crystallization of a liquid phase of two metals of different valences; b) formation of intermediate phases with complex crystal lattices in the form of carbides during solidification of a liquid phase of a transition metal alloyed with carbon; and c) formation of eutectics in electrodeposited metallic alloys as a result of decomposition of a liquid phase into two separate solid phases during its solidification. Intermetallides Cu5Zn8 and Cu6Sn5 in electrodeposited alloys of Cu-Zn and Cu-Sn systems, carbides Fe3C and Cr3C2 in electrodeposited iron and chromium alloyed with carbon, and eutectics in electrodeposited alloys of Sn-Zn and Pb-Cu systems were found.
Enhanced Piezoelectric Properties of Barium Titanate-Potassium Niobate Solid Solution System Ceramics by MPB Engineering
Authors: Shimizu Shigehito , Pulpan Petr , Kumada Nobuhiro , Tanaka Daisuke , Furukawa Masahito , Kuroiwa Yoshihiro , Suzuki Tohru S. , Uchikoshi Tetsuo , Wada Satoshi
Published: July 2010

Barium titanate (BaTiO3, BT) - potassium niobate (KNbO3, KN) solid solution system (0.5BT-0.5KN) ceramics with various microstructures were prepared by conventional sintering method and two-step sintering method using BT and KN nanoparticles. Their microstructures were investigated using X-ray diffraction (XRD) measurement and scanning electron microscopy (SEM), and it was confirmed that two ferroelectric phases, i.e., BT-rich tetragonal and KN-rich orthorhombic phases, always coexisted for all ceramics, which suggested that 0.5BT-0.5KN ceramics had “pseudo-morphotropic phase boundary (MPB)” structure. Thus, the control of the interface area between two phases was important to enhance piezoelectric property. Finally, their piezoelectric property was measured, and the apparent piezoelectric constant d33* increased with increasing interface area.
Influence of Sintering Behavior of ZnO Nanoparticles on J–V Characteristics of ZnO-Based Dye-Sensitized Solar Cells
Authors: Ueno Shintaro , Fujihara Shinobu
Published: July 2010

Dye-sensitized solar cells (DSSCs) are one of the promising photovoltaic devices because of their lower manufacturing cost and higher energy conversion efficiency. Wide-gap, porous semiconducting metal oxides are generally used as electrode materials of DSSCs. Previously we utilized ZnO as DSSC electrodes and achieved a high conversion efficiency of 6.58% by improving the structure of ZnO films. However, open-circuit voltage (VOC), one of the factors to determine the performance of DSSCs, was still at a lower level (≈ 0.60 V) than that of common TiO2-based cells. We believe that the lower VOC is due mainly to the occurrence of recombination. In this work, we tried to enhance VOC by controlling the heating process of electrodes and suppressing the recombination for further development of ZnO-based DSSCs. As a result, we have achieved a higher VOC of 0.725 V, confirming that the sintering behavior (grain growth and/or necking of grains) influenced largely the characteristics of DSSCs.
Rapid Low-Temperature Synthesis of Porous ZnO Nanoparticle Film by Self-Hydrolysis Technique
Authors: Hu Xiu Lan , Masuda Yoshitake , Ohji Tatsuki , Kato Kazumi
Published: July 2010

Porous nano-scale ZnO particle film was rapidly synthesized from a mixing solution of zinc acetate dihydrate – acetone at about 90 °C. The crystal structure and morphology　were clarified by the X-ray diffraction and a field emission scanning electron microscope. The evaporation of higher vapor pressure acetone resulted in the hydrolysis of zinc salt in itself crystalline water. Three morphologies of ZnO (dispersed nanoparticles, dispersed bread chip-shaped particles and flower-like bread chip-shaped assemblies) were observed.
Dielectric Properties of Highly (001)-Plane Oriented SrBi4Ti4O15 Thin Films
Authors: Mizutani Yuki , Uchida Hiroshi , Funakubo Hiroshi , Koda Seiichiro
Published: July 2010

Thin films of a bismuth layer-structured dielectric oxides (BLSD), SrBi4Ti4O15, with preferential crystal orientation were prepared by means of chemical solution deposition (CSD) technique on (111)Pt/(100)Si substrate with bottom nucleation layers of conductive perovskite oxides, LaNiO3 and SrRuO3. CSD technique was utilized for the film preparation of SrBi4Ti4O15. These films possessed highly crystal orientation of (00l) BLSD planes parallel to the substrate surface. The leakage current densities of the SrBi4Ti4O15 films on (100)SrRuO3//(100)LaNiO3/(111)Pt/Ti/(100)Si and on (100)LaNiO3/(111)Pt/Ti/(100)Si were approximately 10-6 and 10-7 A/cm2 respectively. The dielectric constants of these films in a frequency range of 102 - 106 Hz were from 310 to 350 and 250 to 260 respectively. The value of capacitance change of these films in the range from 20 to 300 oC was about +8 and +5% respectively.
Ferroelectric Properties of Magnetoferroelectric YMnO3 Epitaxial Films at around the Neel Temperature
Authors: Yoshimura Takeshi , Maeda Kazuhiro , Ashida Atsushi , Fujimura Norifumi
Published: July 2010

The switching behavior of the ferroelectric polarization of magnetoferroelectric YMnO3 epitaxial films at around the Néel temperature was investigated to discuss the effect of the antiferromagnetic ordering on the ferroelectric domain wall motion. From neutron diffractions to investigate the antiferromagnetic ordering and measurements of polarization-electric field, dielectric constant, and the time constant of the domain wall motion, the change of the domain wall motion is suggested at around 120 K, which is higher than the Néel temperature (~80 K).
Relationships between Negative Differential Resistances and Resistance Switching Properties of SrFeO2+x Thin Films with Excess Oxygen
Authors: Yokota Takeshi , Kito Shinya , Murata Shotaro , Tsuboi Yasutoshi , Gomi Manabu
Published: July 2010

Resistance random access memory (RRAM) is attractive as a next-generation form of nonvolatile memory. We investigated an electric field-induced resistance change of SrFeO2+x film as a candidate for RRAM material. SrFeO2.5-x film prepared at 300 oC showed hysteresis in its current-voltage curve and distinct pulse-switching properties. On the other hand, the sample prepared below 280 oC showed hysteresis in its current-voltage curve but didn’t show pulse-switching properties. The amount of oxygen in the sample and easiness of oxygen migration play important roles in the resistance-switching properties.
Dielectric Properties of HfO2 Films Prepared on Flexible Polymer Substrates Using UV Irradiation
Authors: Suzuki Kazuyuki , Kato Kazumi
Published: July 2010

The HfO2 films were prepared on the ITO/polyimide substrate using alkoxy-derived precursor solutions at low temperature. The HfO2 films prepared by UV-assisted process using the precursor solution modified with diethanolamine had smooth surface and RMS roughness values of HfO2 film were 1.2nm. The electrical properties of HfO2 films were improved by optimization of preparation condition. The leakage current density at 1V was below 10-5A/cm2. The dielectric constant was about 20. The loss tangent was below 0.1.
Preparation of Strontium Titanate / Barium Titanate Complex Nanoparticles Using New Titanium Chelate Compounds
Authors: Goto Takayuki , Pulpan Petr , Takei Takahiro , Kuroiwa Yoshihiro , Wada Satoshi
Published: July 2010

The conditions for strontium titanate (SrTiO3, ST) nucleation and particle growth were investigated for preparation of ST/ barium titanate (BaTiO3, BT) complex nanoparticles. The conditions with and without ST nucleation were clarified. Epitaxial growth of ST layer on the BT substrate particles was studied using both conditions. Unfortunately, the ST/BT complex nanoparticles with heteroepitaxial interface were not prepared, but a new two-step solvothermal reaction method was developed. Finally, the ST/BT complex nanoparticles without heteroepitaxial interface were successfully prepared.
Synthesis and Characterization of Low-Dimensional Structure Photocatalyst BaGeGa6O12
Authors: Nishiya Miki , Uematsu Kazuyoshi , Ishigaki Tadashi , Toda Kenji , Sato Mineo
Published: July 2010

Low-dimensional structure compounds as layered perovskite shows high photocatalytic activity in water splitting. In this study, we investigated that synthesis and characterization of photocatalytic activity of BaGeGa6O12 with a one-dimensional structure. BaGeGa6O12 with loading 0.3wt% RuO2 showed a photocatalytic activity for water splitting into H2 (70.6 μ mol / h) and O2 (28.1 μ mol / h).
Composite Electromagnetic Wave Absorber Made of Both Sendust and Aluminum Particles Dispersed in Polystyrene Resin
Authors: Sakai Kenji , Guan Yang , Sato Yuuki , Yoshikado Shinzo
Published: July 2010

To design an electromagnetic wave absorber with good absorption properties at frequencies above 1 GHz, the frequency dependences of the relative complex permeability μr*, the relative complex permittivity εr*, and return loss were investigated for the composite made of both sendust (an alloy of Al 5%, Si 10%, and Fe 85%) and aluminum particles dispersed in polystyrene resin. It was found that the frequency dependence of μr* for this composite can be changed by adjusting the particle size of aluminum and the volume mixture ratio of sendust and aluminum. Therefore, a flexible design of an absorber with good absorption characteristics was proposed based on the ability to control μr*. The composite made of both sendust and aluminum was found to exhibit a return loss of less than −20 dB in the frequency range of not only several GHz but also around 20 GHz if appropriate volume mixture ratio and particle size were selected.
Low Temperature Synthesis Method of La2O2S2 and Evaluation of the Photocatalytic Activity
Authors: Ohashi Mamoru , Ishigaki Tadashi , Uematsu Kazuyoshi , Toda Kenji , Sato Mineo
Published: July 2010

Photocatalysts for overall water splitting have great potential in solar energy applications. A variety of photocatalysts have shown activity for water splitting. In particular, oxysulfides are the great interest because of their ability to generate H2 and O2 from water under visible light. However, they are generally synthesized under H2S flow, which is an extremely harmful gas for humans. In this study, La2O2S2 was synthesized at low temperature without H2S gas, and its photocatalytic activity was confirmed by hydrogen generation experiments.
Photoluminescence in Bazirite Crystal by Addition of Impurity Ions
Authors: Iwasaki Kenichiro , Takahashi Yoshihiro , Masai Hirokazu , Fujiwara Takumi
Published: July 2010

We examined photoluminescent (PL) and afterglow properties in bazirite (BaZrSi3O9) phases with Sr2+-, Sn4+-, Ge4+-, and Ti4+-impurities, in order to elucidate effect of the impurity-addition on these properties. The bazirite phases studied showed blue PL and afterglow regardless of sort of the impurities. Origin of PL and afterglow emission in the bazirite phase is also discussed.
Low-Frequency Inelastic Light Scattering of Glassy Ba2TiGe2O8 during Heating Process
Authors: Takahashi Yoshihiro , Masai Hirokazu , Fujiwara Takumi , Osada Minoru
Published: July 2010

In-situ observation of inelastic light scattering of boson region in glassy Ba2TiGe2O8 (BTG) was performed during heating process. The in-situ boson observation revealed structural relaxation below glass-transition temperature in the as-quenched sample, suggesting the nanometric structural heterogeneity. Relation of the boson behavior to crystallization tendency is also discussed.
Crystal Structure Analysis of High TC Barium Titanate – Bismuth Perovskite-Type Oxide System Ceramics and their Piezoelectric Property
Authors: Yamato Keisuke , Kumada Nobuhiro , Pulpan Petr , Ohno Satoshi , Moriyoshi Chikako , Kuroiwa Yoshihiro , Lee Bong Yeon , Iijima Takashi , Wada Satoshi
Published: July 2010

Barium titanate (BaTiO3, BT) – bismuth titanate magnesium oxide (Bi(Mg0.5Ti0.5)O3, BMT) solid solution system ceramics were prepared by conventional sintering method in pursuit of the enhancement of the BT Curie temperature (TC, 132 °C). Normal ferroelectric polarization vs. electric-field (P-E) hysteresis loops were observed for BT-BMT ceramics with BMT contents below 20 and above 60 molar%. On the other hand, broad P-E double hysteresis loops were observed for BMT contents from 30 to 50 molar%. The origin was investigated using synchrotron XRD measurement and Rietveld analysis. The crystal structure was assigned to ferroelectric phase with domain-pinning by certain defect structures. A modified phase diagram was proposed on the basis of the temperature dependence of the crystal structure.
Morphology Control of Phosphors Synthesized by Microwave Heating Method
Authors: Toda Ayano , Uematu Kazuyoshi , Ishigaki Tadashi , Toda Kenji , Sato Mineo
Published: July 2010

Ba2Gd3Li3Mo8O32:Eu3+ phosphor was prepared using a single mode microwave oven operated at a frequency of 2.45 GHz and a power of 500 W. The temperature of raw materials, mixtures of BaCO3, Gd2O3, Li2CO3, MoO3 and Eu2O3 subjected to microwave irradiation increased to about 1073 K in 120 s, followed by a sharp drop despite irradiating the raw materials continuously. By measuring the dielectric loss factor of the raw materials at 2.45 GHz, the temperature increased could be attributed to the fact that MoO3 absorbs a high proportion of microwave energy. In the case of the microwave heating method, the phosphor particles were highly non-aggregated.
Evolution of Internal Stress and Influence on Dielectric Properties by Number of Dielectric Layers in MLCC
Authors: Yokomizo Satoshi , Hoshina Takuya , Takeda Hiroaki , Taniguchi Katsuya , Mizuno Youichi , Chazono Hirokazu , Sakurai Osamu , Tsurumi Takaaki
Published: July 2010

We researched the phenomenon that the permittivity of dielectric layers in multilayer ceramic capacitor (MLCC) increases with the number of dielectric layers. Finite element method (FEM) shows that the internal residual stress in MLCC was generated by the difference of thermal expansion coefficient between internal electrodes and dielectric layers. We developed a electric measurement system with applying external stress for understanding the stress influence on dielectric properties. The compressive stress along electric field increased the polarization. The polar nano regions (PNRs) in shell composition dielectrics were easily influenced by stress. Based on these results, the relationship between the number of dielectric layers and their permittivity in MLCCs was explained.
Materials Design and Characterization of (Bi1/2Na1/2)TiO3-Bi(B’,B”)O3 Ceramics
Authors: Oshima Yumiko , Kitanaka Yuuki , Noguchi Yuji , Miyayama Masaru
Published: July 2010

0.995(Bi1/2Na1/2)TiO3-0.005Bi(B’,B”)O3 solid-solution ceramics (B’,B” denote Zn, Mg, Ni, Ti, Nb) were fabricated and their ferroelectric properties were investigated. Based on the structural characteristics of Bi(B’,B”)O3 analyzed by first-principles calculations, a materials design for obtaining a large piezoelectric strain is proposed: an index Z= Ps∙(ε33*∙s33)1/2, where Ps is spontaneous polarization, ε33* is relative permittivity and s33 is elastic compliance. A positive correlation was observed between Z and effective piezoelectric constant d33* observed for strain measurements.
Crystal Growth and Ferroelectric Properties in Bi0.5K0.5TiO3-Bi0.5Na0.5TiO3 Crystals
Authors: Morishita Akifumi , Kitanaka Yuuki , Izumi Makoto , Noguchi Yuji , Miyayama Masaru
Published: July 2010

Single crystals of x (Bi0.5K0.5)TiO3-(1-x)(Bi0.5Na0.5)TiO3 (BKT-BNT) solid solution were grown by a flux method, and their ferroelectric properties were investigated along [100]cubic (the cubic notation). While the flux growth soaked at 1250 °C led to the crystals with a composition of x less than 0.14, the crystals with x of 0.45 were obtained by decreasing soaking temperature to 1150 °C. The crystals of BKT-BNT (x = 0.45) exhibited a relatively large remanent polarization of 39  C/cm2 and a low coercive field of 23 kV/cm.
Advantageous Effect of Macroporous TiO2 Particles on Dye-Sensitized Solar Cells
Authors: Hitachi Naohiro , Fujihara Shinobu
Published: July 2010

In dye-sensitized solar cells (DSC), large-size particles in photoanodes can act as　light-scattering center to enhance light harvesting efficiency. In this study, macroporous secondary　TiO2 particles were prepared by a spray drying method and were introduced to DSC. A few kinds of　layered structures were fabricated as photoanodes to evaluate effects of macroporous particles. It was　found that open circuit voltage increased due to the presence of macroporous particles. A photoanode　composed of stacked nanoparticles and macroporous particles showed better cell performance.
Synthesis and Characterization of La0.8Sr0.2Ga0.8Mg0.2O3-δ Nano-Particle by Aerosol Plasma Pyrolysis
Authors: Myoujin Kenichi , Toriyama Araki , Kodera Takayuki , Ogihara Takashi
Published: July 2010

Spherical La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM) precursor powders were synthesized by aerosol plasma pyrolysis using an aqueous solution of metal nitrate. As-prepared powders obtained by this method were found to have a spherical morphology with a bimodal size distribution of nanosized (primary) and submicron-sized (secondary) particles. The average size of the primary particles was less than 100 nm. X-ray diffraction (XRD) patterns showed that as-prepared powders crystallized to LSGM and other phases. XRD revealed that LSGM pellets were crystallized to a perovskite structure after sintering at 1300 °C for 10 h.
Preparation and Electrochemical Properties of C/LiMnPO4 for Lithium-Ion Battery by Spray Pyrolysis
Authors: Suetsugu Yuichi , Hujita Atsushi , Kodera Takayuki , Ogihara Takashi
Published: July 2010

Spherical C/LiMn1-XMXPO4 (M=Mg, Zn) cathode materials were successfully prepared by spray pyrolysis. An olivine structure was obtained by heating at 973 K under argon/hydrogen (5%) atmosphere. Citric acid was used as the carbon source. Scanning electron microscopy (SEM) showed that the materials had spherical morphology. The electrochemical properties of the cathode were also estimated by the rechargeable capacity and cycle performance. The first discharge capacity of C/LiMn1-XZnXPO4 (X = 0.1) was approximately 60 mAh/g　at 0.1 C.
Detectors in Barrier Structures of Metal-Lamellar Semiconductors
Authors: Mehrabova Matanat
Published: July 2010

Recently peaceful use of the nuclear energy and radioactive nuclides has increased the radiation pollution factor in the world and radiation safety problems have become actual ones. The development of the nuclear power engineering, protection and processing of radioactive wastes of nuclear reactors, the use of radioactive isotopes in national economy, nuclear explosion, industrial wastes and etc. may cause the radioactive pollution of the environment. In the case of such pollution the environment as well as living organisms are exposed to radioactive radiation (a-, b-, γ- etc.). Radioactive substances emit radioactive rays and as their decay time varies for natural and artificial radioactive substances the time of their environmental effect ranges from some years to million years.
BEM Simulation of 3D Updated Resin Front for LCM Processes
Authors: Gantois Renaud , Cantarel Arthur , Félices Jean Noel , Pirc Nicolas , Schmidt Fabrice
Published: July 2010

The use of composite materials in large structures has increased in recent years. Aircraft industry has recently begun to investigate the field of Liquid Composite Molding (LCM) through research programs because of its ability to produce large parts at low cost. The present paper focuses on modeling a 3D radial impregnation through an anisotropic fibrous perform. As a preliminary work, it is assumed an isothermal flow and no hydro-mechanical coupling. Governing equations are Darcy’s law and mass conservation. Simulation is performed combining Boundary Element Method (BEM) with a lagrangian moving mesh method. An analytical solution is developed to assess the numerical model.
Study of DGEBA and Novolac Adhesives Hydrothermal Ageing for a Ceramic/ Steel Substrates Bonding Assembly
Authors: Gaussens Clélia , Nassiet Valérie , Hassoune-Rhabbour Bouchra
Published: July 2010

The industrial application (not described for confidential reasons) needs the assembly of a ceramic piece and a steel one. This PhD research work aims to provide a reliable industrial bonding between ceramic and steel substrate using structural adhesive. This industrial joint shall withstand a wide range of temperature with pretty brutal thermal changes and also severe humidity conditions. As prerequisite to this bonding assembly qualification, the purpose of this work is the study of the durability, in a hot-wet environment. Depending on the formulations, we observe different behaviours in term of weight uptake, morphological, thermomechanical and chemical modifications of the epoxy network.
A Review of Dye Incorporated Conducting Polymers Application as Sensors and in Solar Cells
Authors: Matoetoe Mangaka
Published: July 2010

Dye doped polymers (DCPs) has a wide application based on their optical and electrochemical properties. Dye sensitisation of conducting polymeric materials has gained a wide theoretical interest and practical application in sensors and solar cell technology. This review gives a broad summary on synthesis, the effect of the presence of dye in the polymer (properties, structure and conductivity), application in sensors and dye sensitised solar cells. Different sensing modes are also discussed as well as the effects of post polymer modification with dyes in sensors. In solar cells, the role of DCPs in light harvesting is summarised using examples. Finally, perspectives and the advantages of dye modification or sensitisation of polymers in sensors and solar cells are included.
Electrochemical and Spectroscopic Dynamics of Nanostructured Polynuclear Sulphonic Acid-Doped Poly(2, 5-dimethoxyaniline)
Authors: Klink Michael , Akinyeye Richard , Somerset Vernon , Sekota Mantoa , Baker Priscilla Gloria Lorraine , Iwuoha Emmanuel Iheanyechukwu
Published: July 2010

Conducting and electroactive nanostructured poly(2, 5-dimethoxyaniline), PDMA, doped with anthracene sulphonic acid, ASA, and phenanthrene sulphonic acid, PSA, respectively, were prepared by oxidative polymerisation of 2, 5-dimethoxyaniline, DMA, with ammonium persulphate as oxidant. Scanning electron microscope, SEM, images of the polymers showed well defined nanotubes and fibrils with diameters of between 50 to 100 nm and 200 to 300 nm for PDMA-ASA and PDMA-PSA, respectively. Evidence of the incorporation of ASA and PSA into the PDMA backbone was provided by UV-Vis and FTIR analyses. Electrochemical interrogation of the sulphonic acid-doped polymers by cyclic voltammetry showed that both PDMA-ASA and PDMA-PSA exhibit quazi-reversible electrochemistry. The standard rate constant, ko, for the charge transfer reactions of PDMA-ASA and PDMA-PSA were 3.81 x 10-4 cm s-1 and 3.27 x 10-5 cm s-1, respectively. There was a relationship between the ko value and the formal potential, E0ʹ, of the polymeric nanomaterial. PDMA-ASA that had larger ko value gave an E0ʹ value of 134 mV which was lower than that of PDMA-PSA by 19 mV, indicating that PDMA-ASA has lower activation energy than PDMA-PSA for the electron transfer process Electrochemical impedance spectroscopy over a range of potentials showed that the polymeric nanotubues exhibited high conductivities, though the SA-doped polymer was more conducting.
X-Ray Photoelectron Spectroscopy Characterization of Polyaniline-Cellulose Ester Composite Membranes
Authors: Qaiser Asif A. , Hyland Margaret M.
Published: July 2010

X-ray photoelectron spectroscopy (XPS) is a promising technique employed for the study of conducting polymers and their composites. XPS was used to study the surface chemistry of polyaniline-mixed cellulose ester (PANI-ME) composite membranes prepared by various chemical oxidative polymerization techniques such as insitu solution, vapour phase polymerizations and aniline polymerization using a two-compartment permeation cell. Hydrolytic degradation of surface deposited PANI and scission of cellulosic chains due to x-ray irradiation inside the XPS chamber influenced the quantification of polyaniline deposition levels as well as oxidation and doping states in PANI-ME membranes. N1s core level spectra allowed characterization of the PANI deposition level, its oxidation state and x-ray induced cellulosic ring cleavage. C1s and O1s core level spectra revealed PANI hydrolysis at the membrane surface. These degradation phenomena influence the performance of PANI composite membranes used specifically in electrodiffusion applications. It was shown that successful quantification of PANI deposition levels and its oxidation state on microporous mixed cellulose ester membranes using XPS could be realized by incorporating the degradation effects in the characterization results.
Optical and Electrochemical Properties of a New Donor-Acceptor Type Conjugated Polymer Derived from Thiophene, Carbazole and 1,3,4-Oxadiazole Units
Authors: Manjunatha M.G. , Adhikari Airody Vasudeva , Hegde Pramod Kumar
Published: July 2010

A new donor-acceptor type poly[3-{5-[3,4-didecyloxy-5-(1,3,4-oxadiazol-2-yl)thiophen-2-yl]-1,3,4-oxadiazol-2-yl}-9-dodecyl-9H-carbazole] (P) has been synthesized starting from thiodiglycolic acid and 9H-carbazole through multistep reactions. The polymer has been synthesized through precursor polyhydrazide route. The weight average molecular weight of the polymer was found to be 7210. The polymer exhibited intense green fluorescence in solid sate. Cyclic voltammetric experiments showed that the polymer has low-lying LUMO (-3.55 eV) and high lying HOMO (-5.77 eV) energy levels due to the presence of alternate donor and acceptor units. The optical and electrochemical studies reveal that the new polymer (P) is a promising material for the development of polymer light emitting diodes (PLEDs).
Nonlinear Optical Studies on a New Poly{2-(biphenyl-4-yl)-5-[3,4-didecyloxy-5-(1,3,4-oxadiazol-2-yl)thiophen-2-yl]-1,3,4-oxadiazole}
Authors: Hegde Pramod Kumar , Adhikari Airody Vasudeva , Manjunatha M.G. , Suchand Sandeep C.S. , Reji Philip
Published: July 2010

Measurements of nonlinear optical properties of a newly synthesized thiophene based polymer are reported. The nonlinear transmission measurements were performed on the polymer dissolved in N,N-dimethylformamide by employing the single beam Z-scan technique using a Q-switched laser output at 532-nm. The polymer shows strong optical limiting behavior, where the transmittance decreases when the pump fluence is increased. It was found that an effective three-photon absorption (3PA) model at the excitation wavelength gives the best fit to the obtained experimental data. The value of the 3PA coefficient has been numerically calculated. This study clearly reveals the potential of new polymeric material has, for optical limiting applications.
Synthesis and Characterization of Titanium Dioxide Nanotubes for Photocatalytic Degradation of Aqueous Nitrobenzene in the Presence of Sunlight
Authors: Tayade Rajesh J. , Key D.L.
Published: July 2010

TiO2 derived nanotubes were prepared by hydrothermal treatment of TiO2 (anatase) powder in 10 M NaOH aqueous solution. The crystalline structure, band gap, and morphology of the TiO2 nanotubes were determined by X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), Transmission Electron microscopy (TEM) and N2 adsorption (BET) at 77 K, respectively. It was observed that the surface area of the nanotubes was increased twelve times compared with TiO2 (anatase) powder. The results demonstrated that the photocatalytic activity of TiO2 nanotubes was higher than that of TiO2 (anatase) powder. The photocatalytic activity of the nanotubes was evaluated in presence of sunlight by degradation of aqueous nitrobenzene. Complete degradation of nitrobenzene was obtained in 4 hours using TiO2 nanotubes whereas 85% degradation was observed in case of TiO2 (anatase).
Recent Developments of Nanomaterial Doped Paints for the Minimization of Biofouling in Submerged Structures
Authors: Rawat Jaya , Ray Saptarshi , Rao P.V.C. , Choudary Nettem V.
Published: July 2010

Biofouling prevention remains a major challenge to the chemists, and researchers around the world who are engaged in the development of antifouling paints that can prevent growth of organisms like barnacles, algae and tubeworms on the submerged structures. Growth of organisms on the surfaces exposed to marine and freshwater environment not only reduces the efficiency of such structures, e.g. reduction of heat transfer etc, but also causes structural damages. In order to prevent the growth of organisms on surfaces of the marine and freshwater environments, coatings containing biocides are generally used. However, use of biocides not only leads to the corrosion of the metallic structures in some cases, but it also inflicts severe damage to the aquatic ecosystem. It is thus necessary to develop anti-biofouling paints that are innocuous to both the environment and the structures. One alternative approach may be incorporation of nanoparticles, and preventing bacterial bio-film formation as well as the attachment of larger organisms. Various nanoparticles of metal and their oxides have been recognized to possess antibacterial properties. The development of such materials is a challenge to both the chemist and the biologist, where effective choice of methods that provide relevant information regarding application of the metal nanoparticles in anti-fouling materials, becomes the central objective. The present article is a short review in the area of nanoparticle doped antifouling paints. In addition, some aspects covering our experimental results on the selected bio-fouling paints with dispersed nanoparticles of ZnO, CuO, Al2O3, MgO, TiO2 and Co3O4. It also discusses the techniques used for the characterization of the nanoparticle-doped materials and methods for the determination of their efficacy against bio-film formation.
Relation between Phosphorus Amounts Absorbed by Volcanic Ash Fall Deposits and its Calcinating Temperature
Authors: Watanabe Eiji , Nishizawa Kaori , Maeda Masaki
Published: July 2010

Phosphorus was one of the causative materials of eutrophication that was widely generated in the water system, for instance, the rivers, lakes, and marshes all over the world. The removal method using the phosphorus adsorption ability of volcanic ash fall deposits contained especially the amorphous alumino-silicate mineral was examined. To improve the practicality of durability and the adsorption ability of the volcanic ash fall deposits was heated within the range from 100 to 1100degrees. It was found that the phosphorus adsorption ability of the material was increased as the calcinating temperature was raised, and reached the maximum value at about 600degrees. The amount of adsorption of phosphorus had decreased rapidly when the material was heating to 600degrees or more.
Synthesis of V-ZrSiO4 Blue Ceramic Pigments
Authors: Pyon Kyu Ri , Lee Byung Ha
Published: July 2010

Vanadium doped zircon pigments were prepared by ceramic method from mixture of monoclinic zirconia and silica and sodium fluoride as mineralizer on the colour properties of the pigments was also investigated. The colour of synthesized pigments observed in the absence and the presence of the NaF was green and blue, respectively. They were characterized by X-ray diffraction and UV-Vis spectroscopy.
Synthesis of Forsterite Pigment for Underglaze Colors
Authors: Lee Hyun Soo , Lee Byung Ha
Published: July 2010

The aim of the present investigations was to synthesize pigments based on Ni-doped forsterite (Mg2SiO4) for high temperature underglaze colors by ceramic route. In forsterite Mg2+ can be replaced by Fe2+, Ni2+, Co2+ ion since their ionic radious are close or coincide. NiO doped forsterite green pigments pigments were prepared by ceramic method from mixture of MgO and SiO2 and H3BO3 as mineralizer and the colour properties of the pigments was also investigated. In this experiment, very brilliant and fluorescent light green color hue of pigment was obtained at 1300°C for 3 hours. According to various firing condition, crystalline structure of pigments were chracterised by X-ray diffraction and FT-IR, Raman spectroscopy. And their color characterization were analized by UV-Vis spectroscopy on the ground of CIE L*a*b* measurement.
Effects of Carbon Fiber Architecture on the Microstructure and Mechanical Property of C/C-SiC Composites
Authors: Wang Ji Ping , Lou Jian Yong , Xu Zhuo , Jin Zhi Hao , Qiao Guan Jun
Published: July 2010

C/C-SiC composites were rapidly fabricated by a two-steps processing. Firstly a short-cut carbon fiber felt (SC) and a 2D carbon fiber felt (2D) were densified to C/C composites by a thermal gradient chemical vapor infiltration (CVI) method with vaporized kerosene as a precursor in 2h, 3h, 4h and 5h, respectively. Then the C/C composites were infiltrated and reacted with melting silicon to obtain C/C-SiC composites. The results show that, with increase of the CVI time, the densities of the two types of C/C-SiC composites decrease in the range of 2.28g/cm3 to 2.00g/cm3; their porosities increase ranging from 1.3% to 7.5%; the contents of the β-SiC and the unreacted Si phases in the composites decline. The flexural strength of the 2D_C/C-SiC composite is much higher than that of the SC_C/C-SiC composite when prepared in the same condition.
Artificial Neural Network Approach to Predict Mechanical Properties of 301 Austenitic Stainless Steel
Authors: Chen Zhi Yu , Zou De Ning , Yu Jun Hui , Han Ying
Published: July 2010

In this study, the effect of original thicknesses of plate, the thicknesses of plate after rolling and rolling reduction on the strength in 301 stainless steel was modeled by means of artificial neural network (ANN). The experimental data were collected to obtain training set and testing set. The normalization method was employed for avoiding over-fitting. The optimal ANN method architecture was determined by according to the trial and error procedure. The results of the ANN model were in good agreement with experimental data. As can be seen from the result, we believe that the neural network model can efficiently predict the relationship between mechanical properties and rolling reduction in 301 austenitic stainless steel.
Synthesis of Ternary Machinable Al2O3/Ti2AlC Composites by High Energy Milling and In Situ Hot-Pressing Method
Authors: Wang Fen , Liu Bo Bo , Zhu Jian Feng , Li Ya Ling
Published: July 2010

Al2O3/Ti2AlC composites were synthesized by high energy milling and hot-pressing at 1200°C in a vacuum furnace with a pressure of 4.8×10-2 Pa, using Ti, Al and C powder as raw materials. The effect of sintering temperature on the reactions, phase composition and microstructure of the synthesized products were investigated. The results show that the TiC and TiAl intermetallics composite powders were synthesized during the milling process. After the hot pressing, Ti2AlC phase was formed by the reaction between TiC and TiAl. A small amount of Al2O3 was also produced because of the oxidation of Al in the hot press process, which formed Al2O3/Ti2AlC composite together with the Ti2AlC at 1200°C. The fine grained Al2O3 particles disperse within Ti2AlC uniformly, which play a important role to strengthen Ti2AlC matrix, resulting in the increase of flexural strength and fracture toughness from 250 to 275.4MPa, 9.8 to 10.5MPa•m1/2, respectively.
Synthesis of Ti3AlC2 Powder by High Energy Ball Milling and High Temperature Heat Treatment
Authors: Zhu Jian Feng , Qi Guo Quan , Yang Hai Bo , Wang Fen
Published: July 2010

Highly pure Ti3AlC2 powder was fabricated by combination of high energy milling and heat treatment with Ti, C and Al as starting materials. The details of reactions and phase evolution in fabrication process were investigated. The results shown that the Ti-Al intermetallics, Ti3AlC2 and TiC were formed in high energy milling. The as-milled powders were heat treated subsequently, and the Ti3AlC2 powder with high purity was produced from the reaction among Ti-Al intermetallics, Ti3AlC2 and TiC at relative low temperature (1100 °C).
Fabrication of Lotus-Type Porous Magnesium with Anisotropic Directional Pores by Mold Casting Technique
Authors: Sugihara K. , Suzuki S. , Nakajima Hideo
Published: July 2010

Lotus-type porous magnesium ingots were fabricated in pressurized hydrogen atmosphere through a mold casting technique. The mold consists of two cooling blocks placed at the bottom and one lateral side. It was found that the pores started to grow upwards and horizontally and the both directional pores collapsed and then shifted to the direction. Such anisotropic growth of pores is in good agreement with the map of temperature gradient predicted by two-dimensional finite differential analysis.
Synthesis and Electronic Transport Properties of Sn-Doped CoSb3
Authors: Park Kwan Ho , Jung Jae Yong , Lee Jung Il , Jang Kyung Wook , Kim Whan Gi , Kim Il Ho
Published: July 2010

Sn-doped CoSb3 skutterudites were prepared by encapsulated induction melting and their electronic transport properties were examined. The Sn dopant generated excess charge carriers, which increased in concentration with increasing Sn doping content. However, the carrier mobility decreased with increasing doping content, indicating a decrease in the hole mean free path by impurity scattering. The Seebeck coefficient decreased and the electrical resistivity decreased slightly with increasing the carrier concentration due to the reduced carrier mobility by impurity scattering. The lattice thermal conductivity was dominant in the Sn-doped CoSb3 skutterudites.
Fabrication of Lotus-Type Porous Iron by Thermal Decomposition Method
Authors: Ide Takuya , Wada Takehiro , Nakajima Hideo
Published: July 2010

Lotus-type porous iron was fabricated by continuous zone melting technique through thermal decomposition of chromium nitride(Cr1.18N). Nitrogen dissolves into the molten iron through thermal decomposition of Cr1.18N. When the molten iron is solidified in one direction, insoluble nitrogen forms the directional gas pores aligned along the solidification direction. The porosity increases with increasing transfer velocity. For most of lotus metals fabricated by pressurized gas method, the porosity does not change with the transfer velocity owing to constant gas solubility in liquid and solid phase. On the other hand, the porosity of lotus metal fabricated by thermal decomposition method depends on the transfer velocity. This difference is attributed to the decomposition behavior of gas compound dependent upon the heating rate.
EPP (Expanded Polypropylene) Media for Treating Trace Metals from Road Runoff: Performance Risk Assessment Using Uncertainty Analysis
Authors: Kang Sung Won , Kim Seog Ku , Yun Sang Leen , Oh Hye Cheol , Ahn Jae Hwan
Published: July 2010

EPP(Expanded Polypropylene) media with a large surface area was developed to treat the first flush of storm water from motorway. A series of studies have been carried out concerning the main mechanism of physical characteristics with the filtration and adsorption of EPP media in EcoTank system in order to evaluate the performance risk for treating trace metals (Cd, Cr, Cu, Pb and Zn) under uncertainty. In view of quantitative and qualitative risk analysis, this study assesses the uncertainty analysis involved in predicting of treating heavy metals from road runoff using an EcoTank system. Results of treatment performance estimation after the treatment of trace metals using an uncertainty analysis were 50.0.% probability (class 3; moderate) for Cd, 52.0% probability (class 4; high) of Cr, 47.1% probability (class 3; moderate) for Cu, 44.4% probability (class 3; moderate) for Pb and 51.2% probability (class 4; high) for Zn, respectively. The performance risk values of all the heavy metals satisfied the acceptable criteria.
Optimization Design of the Bonding Property between Flanges and Web Plates of Wood I-Joists
Authors: Hu Ying Cheng , Zhang Xu Jie , Cheng Fang Chao , Zhang Li , Li Jin
Published: July 2010

Wood I-joists is a kind of wood-based engineering material which was widely used in wood construction. As it is in fact, the property of I-joists are influenced not only by shear stress but also by a part of normal stress when they are taking into application. In this study, the effects of different factors were evaluated on the tensile property of the wood I-joists. The factors include the depth of the tanks on the flanges, the amount of glue spread and adhesive type. The method of orthogonal test was used in the process of the experiment design, and tensile test were taken during the experiment at the aim of testing the property of the I-joists using a universal mechanical testing machine. Ultimately, it has been discovered that the factor of adhesive type is the most influential one in the three factors which had been listed. So this paper offers the optimal fabrication technology of the I-joists to make it is possible for the increase of reliability when wood I-joists are taken into application.
Effect of Complexing Agent on Morphology and Crystal Structure of La1-xCexCoO3 (x=0, 0.2, and 0.4) Perovskite-Type Mixed Oxides Catalyst Prepared by Sol-Gel Method
Authors: Soongprasit Kanit , Aht-Ong Duangdao , Sricharoenchaikul Viboon , Atong Duangduen
Published: July 2010

. La1-xCexCoO3 (x=0, 0.2, and 0.4) perovskite-type mixed oxides using polyvinyl alcohol (PVA) as complexing agent at two molar ratio of metal ion to PVA (1:1 and 1:2) were successfully prepared by sol-gel process. The precursor included lanthanum (II) nitrate hexahydrate, cerium (II) nitrate hexahydrate, and cobalt (II) nitrate hexahydrate where polyvinyl alcohol was added as complexing agent. The suitable condition of Cerium (Ce) substitution and PVA molar ratio were established for further application in hydrocarbon conversion to high value added products. TGA thermogram of as-prepared precursor showed that PVA absolutely decomposed at temperature higher than 500°C. XRD patterns of calcined catalyst showed both LaCoO3 rhombohedral and CeO2 cubic structures that confirmed the formation of mixed crystal structure. Nevertheless, Co3O4 slightly appeared with low peak intensity which came from the oxidation reaction of as-prepared catalyst during calcinations. XRD showed that PVA did not effect to crystal structure of synthesized catalyst. Higher PVA content added in the precursor cause the reduction of crystal growth of catalyst in calcinations step. In contrast, morphology of catalyst is directly related with PVA content such that the spongy and sheet-like structure were formed with increasing PVA content which prevented the agglomeration of particles. The results showed that PVA content play an important role in morphology of perovskite-type mixed oxide catalysts but did not affected to their crystal structures.
Application of Polymer Media to the Site for Treatment of Pollutants in Rainfall Effluent of Urban District
Authors: Yun Sang Leen , Kang Sung Won , Kim Seog Ku , Ahn Jae Hwan , Oh Hye Cheol
Published: July 2010

With the acceleration of urbanization, impervious surface spreads due to increase of rainfall effluent; consequently, plenty of pollutants occur instantaneously, and severity of a problem caused by being worse of the river and water system is coming to the forefront. Nation Water Quality Inventory reported that 30% of the cause of water quality getting worse is caused by non-point pollutants, and 64% of the cause of polluted water quality of the lake around North Carolina is resulted from non-point pollutants of urban area. This study developed a system that treats and removes pollutants occurring in an impervious area of the urban district by using polymer media. Polymer media, made from polypropylene materials, has float ability and an irregular form. Also this study showed that polymer media has an excellent filtering function of pollutants due to porosity on the surface, and the increase of specific surface area, so that it has an excellent function to remove suspended solids (SS), organic materials and nutritive salts in effluent water on the road side.
Treatment efficiency of pollutants in an impervious area of the urban district through application of polymer media to the site is 92.1% and average EMC of suspended solids (SS) is 19.74 mg/L.
In addition, treatment efficiency of CODcr is 82.3%, and the efficiency of TN and TP is 50.4% and 73.9%, respectively.
Elastic and Plastic Deformation Behaviors of Lotus-Type Porous Copper
Authors: Tane Masakazu , Nakajima Hideo
Published: July 2010

The elastic and plastic deformation behaviors of lotus-type porous copper (lotus copper) with cylindrical pores oriented in one direction were investigated using two acoustic methods (resonant ultrasound spectroscopy and acoustic emission method). All the independent components of elastic stiffness were determined by resonant ultrasound spectroscopy combined with electromagnetic acoustic resonance method, which revealed that the Young’s modulus exhibits the anisotropy originating from the anisotropic porous structure and anisotropic matrix texture. The porosity dependence of the anisotropic Young’s modulus can be calculated by the micromechanics modeling based on effective-mean-field theory. The tensile deformation behavior of lotus copper was analyzed by acoustic emission method, which revealed that many burst acoustic emission signals are detected during the tensile deformation. This implies that many cracks are formed during the tensile deformation.
Effect of Atmosphere on the Crystallization of Amorphous Silicon Nitride
Authors: Fan Lei , Wang Hong Jie , Yue Jian She
Published: July 2010

The green bulk amorphous silicon nitride was prepared by cold isostatic pressing without the presence of sintering additives, using an amorphous silicon nitride as raw powder. The crystallization behavior of amorphous silicon nitride was investigated under N2, Ar atmosphere and vacuum using X-ray diffractometry (XRD). The effect of atmosphere on the process and the end products of crystallization of amorphous silicon nitride was studied. The single phase beta-Si3N4 and Si2N2O could be prepared in the different sintering atmosphere as the end product. The possible reaction process was discussed also.