bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Burr Formation in Face Milling of Stainless Steel with Chamfered Cutting Tool
Authors: Jing Lu Lu , An Qing Long , Chen Ming
Published: March 2009

Due to the properties such as high strength and high toughness, burr was commonly
produced in the machining of stainless steel 1Cr18Ni9Ti, especially when a chamfered cutting tool
was used. This study investigated the effects of chamfering geometry of cutting edge and machining
parameters on burr formation and presented active control methods to minimize burr size on the exit
end based on the experimental research in milling of 1Cr18Ni9Ti. Experiments of face milling with
various cutting edge geometric features were conducted. Maximum height and thickness of exit burr
and exit side burr were measured. As a result, a proper chamfering geometry that combined the
advantages of enhancing the cutting edge strength and obtaining favorable burr types was presented.
The experimental results also showed that a relatively high cutting speed was helpful in reducing burr
formation; proper medium feed rate and axial depth were favorable for the minimization of burr size.
This research is beneficial for precise machining of stainless steel.
Characterization of LiNbO3 Powder Prepared by Citrate Gel Method
Authors: Onnom S. , Wongratanaphisn D. , Supaphol Pitt , Udomsamuthirun Pongkaew , Nilkamjon T. , Radrang S. , Sonkrua S. , Payoogthum S.
Published: March 2009

Lithium niobate powder (LiNbO3) were synthesized by citrate gel method using LiNO3, Nb2O5, citric acid and HF as starting materials. LiNO3 was dissolved in distilled water that activated into LiOH. Nb2O5 was dissolved in minimum amount of HF at 370C for 20 h. that activated into NbF5. Then citric acid, LiOH, and NbF5 were mixed in stoichiometric ratio. On heating at 1000C for 3-4 h. a yellowish gel is formed. Lithium niobate powders were obtained after calcination at 550-7000C. The effect of calcination temperature at various temperatures ranging from 5500C to 7000C were investigated. The phase and chemical composition of the synthesized powders were characterized by using XRD, SEM, TEM, FTIR and EDX. We found that the lithium niobate crystallize phase formed when the calcination temperature at 6500C with average particle size of around 100 nm .
The Effect of Excess PbO on Crystal Structure and Microstructure of (Pb0.925Ba0.075)TiO3 Ceramics
Authors: Bongkarn Theerachai , Sumang R.
Published: March 2009

In this work, we studied the effect of excess PbO doping on lead barium titanate [(Pb0.925Ba0.075)TiO3; (PBT)] ceramic. PBT was prepared via a mixed oxide method with various PbO levels (-3, 0, 1, 3, 5 and 10 wt.%). The excess PbO was added to compensate the loss from evaporation during calcination and sintering at 800 oC and 1150 oC. It was found that lead barium titanate powders indexed in a tetragonal structure. Impurity phases of lead oxide (PbO), titanium oxide (TiO), and lead dioxide (PbO2) were detected in the calcined powders with higher than 1 wt% of excess PbO. The impurity phase was not obtained in any ceramic samples. The c/a ratios decreased with an increasing excess of PbO in both calcined powders and sintered pellets. The average particle size and the average grain size of the PBT increased with the increase of PbO. The shrinkage plots showed a maximum peak for the 1 wt.% sample which was also the most dense sample.
Effect of MnO2 Impurity on the PZT-PMN System Ceramics for Piezoelectric Transformer
Authors: Suwan Y. , Niyompan Anuson , Tipakontitikul Rungnapa , Laoratanakul Pitak
Published: March 2009

The PZT-PMN ceramics system was derived from Pb(Zr0.5Ti0.5)O3 and Pb(Mg2/3Nb1/3)O3 based compositions those obtained via the columbite method. The effect of MnO2 addition on microstructure, physical properties and piezoelectric properties were investigated. In this study, the composition with PZT/PMN ratio of 1:1 was selected. To observe the effect of MnO2 adding, its concentration was varied in range 0-10 mol%. Green pellets were sintered at temperature 1250oC for 4 hours. For piezoelectric investigation, the ceramics pellets were subjected to a poling process. The XRD results show that there is no phase transformation observed for all sintered PZT-PMN samples with presence of MnO2. The SEM micrographs reveal that MnO2 can enhance sinterability as evidenced by lowering of porosity and increasing of grain size with increasing of MnO2 content. Increasing of linear shrinkage and apparent densities also confirmed such effect. Improvement of d33 from 28 to 114 pC/N could only found for MnO2 in range 0 to 4 mol%. For higher MnO2 content, there is only slightly increased. However, increasing of kp with increasing of MnO2 is clearly observed. While dielectric constant measured at room temperature and at frequency 1 kHz is higher for ceramics without MnO2 doping and it decreases with increasing MnO2 concentration. The temperature dependence of relative dielectric constant go to peak of value about 6000 at temperature around 180oC and shifting of these peaks with frequency can only be observed for samples with higher MnO2 content. This indicates a normal ferroelectric behavior for sample with lower MnO2 and there are converted to relaxor after MnO2 increased.
Effects of Calcination Temperatures on Phase and Morphology Evolution of (Ba0.25Sr0.75)(Zr0.75Ti0.25)O3 Powders Synthesized via Solid-State Reaction and Combustion Technique
Authors: Thongtha Atthakorn , Angsukased Kritsana , Bongkarn Theerachai
Published: March 2009

The effect of calcination temperatures (1000-1400 oC) on the phase formation and microstructure of barium strontium zirconate titanate [(Ba0.25Sr0.75)(Zr0.75Ti0.25)O3 ; BSZT] powders were investigated. BSZT powders were prepared and compared by the solid state reaction method and the combustion technique. The higher calcination temperatures increased the percentage of the perovskite phase, but decreased the lattice parameter a. The same crystallographic pure perovskite phase of BSZT powders, which were prepared via the combustion technique were detected above 1300 oC ; which was lower than the calcinations temperature of mixed oxide method by 50 oC. The TGA-DTA results corresponded to XRD investigation. The microstructure of BSZT powders, which were prepared using both techniques, exhibited an almost-spherical morphology and had a porous agglomerated form. The average particle sizes of BSZT powders prepared via the combustion technique (0.13-0.30 µm) and the solid state reaction method (0.18-0.38 µm) were increased with the increase of calcinations temperatures
Ferroelectric and Dielectric Aging Effects of Fe3+/Nb5+ Hybrid-Doped Barium Titanate Ceramics
Authors: Prasertpalichat Sasiporn , Unruan Muangjai , Tungsritrakul J. , Yimnirun Rattikorn
Published: March 2009

It is well known that acceptor and donor doping results in opposite ferroelectric aging effects; however, the aging effects in hybrid-doped (acceptor+donor) has remained unclear. Thus, the aging effect of dielectric and ferroelectric properties in Fe3+/Nb5+ hybrid-doped BaTiO3 ceramics was investigated in this research. The concentration of acceptor dopant (Fe3+) was fixed at 1 mol% while that of donor dopant (Nb5+) was varied from 0.5-2.0 mol%. XRD technique was used to study the phase morphology. Before measuring dielectric and ferroelectric aging effect, all samples were deaged at 250 °C for 1 hour. The results showed that the dielectric properties of all deaged samples have decreased exponentially with time. The deaged samples with 0.5 and 1.0 mol% of Nb5+ obviously showed double hysteresis loop while that with higher concentration of Nb5+ (1.5-2.0 mol%) showed the rectangular (normal) hysteresis loop. The explanations based on the effect of defect dipole were discussed.
Materials of Nanocrystalline Sr1-xBaxBi4Ti4O15 for Piezoelectric Sensor
Authors: Manaf N. A. A. , Salleh Muhamad Mat , Yahaya Muhammad
Published: March 2009

The nanocrystalline Strontium Barium Bismuth Titanate (SBBT) thin films with structure of Al/TiO2/SBBT/TiO2/RuO2/SiO2/Si were fabricated using sol-gel technique. The source materials are bismuth acetate Bi(CH3COO)2, barium acetate Bi(CH3COO)2, strontium acetate Sr(CH3COO)2 and titanium butoxide (Ti(OC4H9 )4). Different nanostructures of the films were prepared with un-annealed condition as well as after annealing at three different temperatures of 400, 500 and 6000C, in air for 2 minutes. The structure of SBBT thin films have been systematically studied by XRD, AFM, SEM and dielectric constant measurement. For the sensor device measurement, the SBBT thin film pressure sensors were tested by pneumatic loading method at pressure range between 0 to 450 kPa. It was found that the sensing properties of the films were affected by the crystalline nature of the films. It is shown that there is a linear relationship between the crystallization, grains size and dielectric properties with the sensing response of the film towards pressure.
Enhanced the Performance of Fluorescence Gas Sensor of Porphyrin Dye by Using TiO2 Nanoparticles
Authors: Yusoff Nurul Huda , Salleh Muhamad Mat , Yahaya Muhammad
Published: March 2009

Fluorescence gas sensor was developed to identify the presence of volatile organic compounds by using porphyrin dye thin film. The porphyrin dye used was iron (III) meso-tetraphenylporphine chloride. The porphyrin thin film was deposited on quartz substrate using self-assembly through dip coating technique. The sensing properties of the thin films toward volatile organic compounds; ethanol, acetone and 2-propanol were studied using luminescence spectrometer. In presence of air and volatile organic compounds, thin films produced different emission spectra and ease for chemical identification process. To improved the sensing performance, TiO2 nanoparticles colloid were prepared, coated with porphyrin dye and deposited as thin film. It was found that the thin film of TiO2 nanoparticles coated with porphyrin dye has more intensive interaction toward volatile organic compounds than porphyrin thin film, and improved the selective property. This may be due to the nanostructured thin film provided more surface area for dye molecules to react with VOCs.
Water Absorption and Phase Transition of Calcium Carbonate in the Sea Water Mussel (Anadara Granosa)
Authors: Siriprom W. , Onreabroy Wandee , Limsuwan Pichet
Published: March 2009

The main purpose of this work is to study the structure of Anadara granosa shell sample and its structural transformation upon heat treatments. The sample was ground and characterized as powder throughout this work. Structural identifications of all samples were characterized, and determined qualitatively by using X-ray diffraction, IR spectroscopy and thermogravimetry measurement (TGA). It was found that the specimen is made of aragonite, a common phase of CaCO3 mineral. The powder sample was annealed at specific temperatures over the range of 200°C - 900°C and the effects of heat treatment on the structure of Anadara granosa shell samples were studied. The results show that aragonite transforms to calcite at the temperatures between 200°C and 400°C and completely becomes calcite between 400-500°C. Then, the calcite transforms to calcium oxide at the temperatures between 500°C - 900°C. The exact structures and quantities of phase at different annealing temperatures were studied by Rietveld refinement. In our study, we also used IR spectroscopy and TGA to study the effect of water absorption of the samples on the phase transformation.
Temperature Effect on Chicken Egg Shell Investigated by XRD, TGA and FTIR
Authors: Naemchanthara Kittisakchai , Meejoo S. , Onreabroy Wandee , Limsuwan Pichet
Published: March 2009

The main purpose of this work is to study the structure of Anadara granosa shell sample and its structural transformation upon heat treatments. The sample was ground and characterized as powder throughout this work. Structural identifications of all samples were characterized, and determined qualitatively by using X-ray diffraction, IR spectroscopy and thermogravimetry measurement (TGA). It was found that the specimen is made of aragonite, a common phase of CaCO3 mineral. The powder sample was annealed at specific temperatures over the range of 200°C - 900°C and the effects of heat treatment on the structure of Anadara granosa shell samples were studied. The results show that aragonite transforms to calcite at the temperatures between 200°C and 400°C and completely becomes calcite between 400-500°C. Then, the calcite transforms to calcium oxide at the temperatures between 500°C - 900°C. The exact structures and quantities of phase at different annealing temperatures were studied by Rietveld refinement. In our study, we also used IR spectroscopy and TGA to study the effect of water absorption of the samples on the phase transformation.
The Effect of Organic Modificaition Method onto Montmorillonite on Mechanical Properties of Natural Rubber
Authors: Thongpin Chanchai , Tangchantra N. , Kaewpetch P. , Dejkun J. , Chartsiriwattana A.
Published: March 2009

Montmorillonite is a type of clays that has been used to reinforce polymer including rubber. Therefore this research is aimed to modify mechanical properties of natural rubber (NR) using montmorillonite (MMT) comparing with the organic modified montmorillonite (CTAB-MMT) and organic molecule grafted MMT. The affect of MMT, CTAB-MMT and HTMS-g-CTABMMT on cure characteristics of NR were studied. It was found from the research that the increase of MMT content could prolong the scorch time whereas CTAB-MMT and HTMS-g-CTABMMT could shorten the scorch time. The cure times of the compounds in all cases were not much different. In term of mechanical properties, modulus, tensile strength and tear strength of NR/HTMS-g-CTABMMT vulcanizate were higher than those of NR/MMT and NR/CTAB-MMT vulcanizates. Meanwhile, elongation at break of the NR/ HTMS-g-CTABMMT vulcanizate decreased more than the latter cases
Fabrication and Characterization of Sol-Gel Derived PZT/WO3 Ceramics
Authors: Sreesattabud T. , Watcharapasorn Anucha , Jiansirisomboon Sukanda
Published: March 2009

Lead zirconate titanate/tungsten oxide (PZT/WO3) ceramics were prepared from the powders synthesized by a modified triol sol-gel processing method. In this study, the starting materials used for synthesis of PZT-sol were zirconium (IV) propoxide, titanium (IV) isopropxide, lead (II) acetate trihydrate and 1,1,1,- tris (hydroxymethyl) ethane. To prepare PZT/xWO3 powders (where x = 0, 0.5, 1 and 3 wt%), nano-sized WO3 was ultrasonically dispersed and mixed with the PZT sol, dried and calcined at 600°C for 4 h. X-ray diffraction results indicated that fully crystallized powders were obtained. Phase characterization suggested that at high WO3 concentration, the reaction between PZT and WO3 occurred during the calcination process. To prepare PZT/xWO3 ceramics, the powders were pressed and sintered at 1100°C for 6 h. Phase characterization by XRD indicated that the content of WO3 significantly affected tetragonal-to-rhombohedral phase transition. Microstructure of thermally etched samples showed that increasing the content of WO3 decreased grain size of the ceramics.
Effect of Carbon Addition on Dielectric Properties of 0-3 PZT-Portland Cement Composite
Authors: Jaitanong Nittaya , Wongjinda K. , Tammakun P. , Rujijanagul Gobwute , Chaipanich Arnon
Published: March 2009

The dielectric properties of the 0-3 lead zirconate titanate (PZT)-portland cement (PC) composite with carbon addition were investigated. Lead zirconate titanate (PZT), Portland cement (PC) composite and carbon powder were fabricated using 50% of PZT, and varying addition of carbon 1, 2 % by volume. The dielectric properties were measured under room temperature at different frequency from 1kHz-20kHz. Carbon addition was found to slightly increase the dielectric constant of PZT-PC composite at room temperature. The results also show that both the carbon powder addition and frequency affected the dielectric constant and dielectric loss tangent of 0-3 all PZT-PC composites.
Manufacturing Process and Property Evaluation of Functional Composite Yarn-Dyed Woven Fabrics Made from Bamboo Charcoal/Stainless Steel and TPU
Authors: Huang C.I. , Su C.I. , Lou Ching Wen , Hsing Wen Hao , Lin Jia Horng
Published: March 2009

Recently, development of technology increases human life quality and gradually raises the value of health protection in human’s concept. Bamboo has multi-functional including far infrared radiation, deodorization and anion generation. Therefore, bamboo charcoal has been widely used in textile industry. Moreover, development of technology also increased the electromagnetic hazard in human’s daily life. This study aims to develop a manufacturing process of functional composite yarn-dyed woven fabrics. In the manufacturing process, the materials included pure cotton yarn, stainless steel fiber(called metallic yarn) and viscose rayon yarn containing bamboo charcoal (called bamboo charcoal yarn) were used for making the bamboo charcoal/stainless steel composite woven fabric. The composite woven fabrics were woven by using same warp yarn and two kinds of weft yarn that contained bamboo charcoal and stainless steel. The composite fabrics had two different structures. Those fabrics were changed the order of bamboo charcoal yarn and metallic yarn. The ratios of weft yarn were 1 end of bamboo charcoal yarn to 1 end of metallic yarn and 3 ends of bamboo charcoal yarn to 1 end of metallic yarn. Furthermore, the fabrication of composite fabrics that included plain, 2/2 twill and dobby were changed. The composite woven fabrics were finished and laminated by TPU film to enhance the waterproof and vapor permeable functions. The laminated composite fabrics were evaluated by far-infrared coefficient, anion generation rate, water vapor permeability, water resistance, surface electric resistance and electromagnetic shelter property to obtained optimal manufacturing process.
Manufacturing Process and Practical Examination for a 3D Structural Geocell Made from Recycled PET Fibers
Authors: Hsing Wen Hao , Hsieh J.C. , Lin C.W. , Lou Ching Wen , Liu P.T. , Lin Jia Horng
Published: March 2009

In the recycle trend, this study used the low-melt polyethylene terephthalate fiber and the recycle wasted materials in producing nonwoven products. These two materials were combined together to form nonwoven products, which have good drain ability and high stress. Then, the high frequency plastic welding machine was used to manufacture the geocell of three dimension nonwoven cubic structure. This study discussed the bonding strength with different bonding length and width. The results show that the uniform of the bonding area resulted from the high frequency plastic welding machine affects the bonding strength. In low-power (tuner point to 2) bonding strength increases while the bonding time increases.
Temperature Dependence of Optical Constants of Silver Film Studied by In Situ Spectroscopic Ellipsometry
Authors: Rojebuathong S. , Chindaudom P. , Luangtip W. , Horphatum M. , Eiamchai P. , Patthanasetthakul V. , Limsuwan Pichet
Published: March 2009

A silver film was deposited on silicon wafer by DC unbalance magnetron sputtering system. The temperature dependence of the silver film was investigated. The spectroscopic ellipsometry (SE) with the heating of sample stage (HTC100) was employed for the in situ SE measurement under annealing cycles of the sample from room temperature to 300°C in dry nitrogen gas. The results show that the pseudo dielectric constants (<ε1>, < ε2>) of the sample varied with an annealing temperature. The real part of pseudo dielectric constant (<ε1>) of annealed Ag film was slightly changed and the imaginary part (< ε2>) was strongly increased at a photon energy below the optical band gap (3.5-4.5 eV). Furthermore, the pseudo dielectric constant of imaginary part at low energy region was changed due to the enhancement of crystallinity of Ag film at 300°C. All measured SE spectra were fitted by Drude-Lorentz optical model, the scattering time and resistivity were obtained.
Characterization of Anatase and Rutile TiO2 Thin Films Deposited by Two Cathodes Sputtering System
Authors: Witit-Anun N. , Rakkwamsuk P. , Limsuwan Pichet
Published: March 2009

Titanium dioxide, TiO2, thin films were deposited on unheated Si (100) wafers by two cathodes sputtering system. However, during the deposition of TiO2 films only one cathode was used. A pure metallic titanium was used as a sputtering target. Argon and oxygen were used as sputtered gas and reactive gas, respectively. TiO2 films were deposited at the argon and oxygen ratio of 1:4 and a total pressure of 5.0 x 10-3 mbar. The distance between the target and the center point of substrate was 12 cm. For each deposition of TiO2 films, the position of substrate was changed every 2 cm on the radial position of the cathode. The deposition time for each deposition was 60 min. The films were characterized by X-ray diffraction (XRD) technique and transmission electron microscopy (TEM). The XRD results and TEM images show that the crystalline rutile TiO2 films can be successfully deposited on an unheated substrate.
Entangled Photon Generation in a Nonlinear Micro Ring Resonator for Quantum Key Distribution Use
Authors: Sripakdee Chatchawal , Sarpat K. , Suwancharoen W. , Yupapin P. Preecha
Published: March 2009

In analysis of a new technique for quantum key distribution using the entangled photon within a micro ring resonator is presented. The Kerr nonlinear effects type of light circulates in the micro ring resonator is induced into the device. The superposition i.e. four-wave mixing of the propagating waves at resonance is occurred, where the entangled photon is generated. The possible two entangle pairs is described and discussed. The proposed system has shown the potential of using in the realistic system, where such a device scale can be fabricated and performed within the mobile telephone hand set, which means the use of quantum telephone will be realized in the near future.
Improvement of UV Protection Properties in Poly(Methyl Methacrylate) Sheet Coated by Titanium Dioxide/ Poly(Methyl Methacrylate) Hybrid Film
Authors: Panapoy M. , Wannasut P. , Ksapabutr Bussarin
Published: March 2009

Titanium dioxide/poly(methyl methacrylate) (TiO2/PMMA) hybrid films with various amounts of TiO2 containing PMMA resin on PMMA sheets were produced by a tape casting method. TiO2 nanocrystals were prepared using electrospraying process at 400oC under high electric field of 3 kV/cm. The as-sprayed and annealed TiO2 powders were characterized by Raman spectroscopy, XRD, SEM and TEM. The UV absorption for both pristine PMMA sheet and TiO2/PMMA hybrid film on PMMA sheet was measured using UV-Vis spectroscopy. The as-sprayed and annealed TiO2 powders showed anatase preferred orientation. They have higher UV absorption in the range of wavelength between 230 and 370 nm than commercial anatase TiO2 nanopowders. Moreover, the visible light transmittances of anatase TiO2/PMMA hybrid films on PMMA sheets in the range of wavelength between 400 and 800 nm was comparable with those derived from pristine PMMA sheets. Therefore, the resulting hybrid films can block out the UV rays, but are transparent to visible light.
Fluoride and Antimony-Doped Tin Oxide Film by Spray Pyrolysis
Authors: Buntem R. , Kraisingdecha P. , Sadee W.
Published: March 2009

Thin films of undoped, fluoride- and antimony- doped tin oxide on glass were prepared by spray pyrolysis technique. The aerosols were atomized from precursor solution by a commercial ultrasonic generator. Tin chloride(SnCl2.2H2O), ammonium fluoride (NH4F), and antimony chloride (SbCl3) were used as a source for tin, fluoride, and antimony respectively. For the undoped tin oxide film, the solution of 0.8 M tin chloride was used as a precursor solution. While fluoride-doped tin oxide films (FTO), the solution of 0.8 M SnCl2.2H2O in ethanol and varying amounts of NH4F dissolved in 0.2 M HCl (0.6 mL) were used as a precursor solution. The doping concentrations of NH4F were 0, 0.2, 0.3, 0.4, 0.5 and 0.6 M. For the antimony- doped tin oxide films (ATO), the doping concentrations of SbCl3 dissolved in butanol (10 mL) are 0, 0.016, 0.032, 0.048, 0.064 and 0.080 M. The aerosols were sprayed on the hot glass substrates by air at a flow rate of 1 L/minute through a PVC and glass tubing for 20 minutes for every solution. Substrate temperature was kept at 320 ± 15 °C for undoped and fluoride-doped tin oxide films and at 390 ± 20 °C for antimony- doped tin oxide films. The electrical and optical properties of the films were characterized by four-point probe measurement and UV/VIS spectrophotometer. The best FTO film exhibits the resistivity of 53.83 W-cm and the light transmission of 88.18%. While the best ATO exhibits the resistivity of 61.03 W-cm and the light transmission of 86.45%.
Novel Design of a Micro Gyroscope Based Birefringence Measurement for Sensor Applications
Authors: Phiphithirankarn P. , Yabosadee P. , Suwancharoen W. , Yupapin P. Preecha
Published: March 2009

. We propose a new concept of a micro gyroscope which is made by a nonlinear micro ring resonator (i.e. 5-10 microns). The nonlinear behavior of polarized light known as polarization mode dispersion in the micro ring device is introduced by material birefringence (i.e. refractive index), which is described. In practice the measurement of polarization mode dispersion can be performed by projecting the output light into a polarizing beam splitter and detectors, where the change in phase is occurred, and then the birefringence is calculated. In addition, the property of the two orthogonal components (i.e. horizontal (H) and vertical (V) components) can be formed the photon entanglement. Which means the entangled photon can be generated, where the state timing walk-off can also be measured and compensated. The design of micro gyroscope is now capable to reduce the device scale in the micron regime to meet more possible applications such as for the measurement of temperature, pressure, and force based on birefringence sensor, which will be discussed in details.
Mechanical Properties of Hemp Fiber Composites with Carbon Nanotubes Reinforcement
Authors: Longkullabutra Haruthai , Nhuapeng Wim , Thamjaree Wandee , Tunkasiri Tawee
Published: March 2009

An experimental was investigated the condition of reinforcement of hemp fiber and hemp fiber/epoxy resin composites with carbon nanotubes (CNTs).The CNTs were mixed with several liquid such as ethanol, latex, water glue and epoxy resin. These mixtures were added to hemp fiber and prepared the hemp fiber/epoxy resin composites. The mechanical properties of both fiber and composite samples were measured. It was found that the mixture of epoxy resin and CNTs with CNTs ratio of 20 vol% in hemp fiber showed the highest tensile strength of 25.43 N. and the same mixture in hemp fiber/epoxy resin composites showed the highest tensile strength of 31.82 MPa and elongation of 7.40 %.
Electrode Properties of Nanostructured and Amorphous Mg1.75Nb0.25Ni Compound Produced by Mechanical Alloying
Authors: Kashani Bozorg S.F. , Mohri Maryam , Ebrahimi-Purkani A.
Published: March 2009

Nb addition was found to be beneficial to the electrode properties of mechanically alloyed Mg2Ni-based product in 6M KOH solution. Formation of Mg2Ni-based nanocrystalites occurred after 15 and 5h of milling using the initial binary and ternary powder mixtures with stoichiometric compositions of Mg2Ni and Mg1.75Nb0.25Ni, respectively. Further milling of the ternary mixture resulted in the formation of an amorphous phase which became dominant after 30h. Negative electrode made from ternary product after 20h of milling exhibited the highest initial discharge capacity and the longest discharge life. This electrode showed to have a microstructure consisting of nanocrystalline Mg2Ni and an amorphous phase.
Preparation of Nano-Crystalline Boehmite as a Gamma-Alumina Source for the Production of Na.beta-Al2O3 Solid Electrolyte
Authors: Pimsorn P. , Tipakontitikul Rungnapa , Niyompan Anuson , Kanchanarat N. , Tunkasiri Tawee
Published: March 2009

Nano-crystalline boehmite (AlOOH) proposed as a precursor for g-Al2O3 production was prepared using precipitation process. The mixture of two starting solutions of AlN3O9.9H2O and Na2Al2O4 was formed and NaOH was used as pH adjustment. Various preparation conditions, starting pH and temperatures were applied. The results suggested that high purity AlOOH powder could be obtained at solution temperature above 60oC and starting pH was in range 7-11. Their crystalline size increased from 2.4 to 3.9 nm with increasing pH. According to the results, AlOOH from pH 8 and temperature 80oC was selected for producing the g-Al2O3 by calcination in the temperature range of 350oC-1100oC. Transformation from AlO(OH) to g-Al2O3 could be readily observed from the whole temperature range and g-Al2O3 crystalline size was increased with increasing calcination temperature. After the temperature reached 1100oC, transformation to a- and q- phases were also found. Morphology of g-Al2O3 powder shows a strong aggomeration.
Optical Properties of Metal Free and Metal Phthalocyanine by Molecular Band Calculation
Authors: Pengmanayol S. , Osotchan Tanakorn
Published: March 2009

The optical properties of metal-free and metal phthalocyanine were calculated by using density functional theory with various metals including copper, zinc, cobalt, iron and manganese. The polymorphic form of these crystals was employed only for β from. The molecules were optimized with the symmetry of D4h. For the alignments of the molecule in the crystal structures of this polymorphic form which have not been reported in detail, the variation of total energy was examined as a function of the align angles. The align angle at minimum total energy was used for the band calculation. The density functional theory and plane-wave pseudopotential method were used to calculate the energy band structure and electron density of state. The calculated band structures of various metal phthalocyanines can be divided in two groups according to the peak wavelength of the maximum absorption. The first group with the peak wavelength at about 230 nm consists of β-CuPc, β-H2Pc, and β-MnPc while the wavelength of another group for β-CoPc, β-FePc, and β-ZnPc occurs at 350 nm. From the density of state calculation, it indicates that these two transitions originate from the different band and the ratio of the absorption between these states depending on the type of metal in phthalocyanine. The optical absorption was derived to examine the absorption spectra for various metal compositions while the variation in intrinsic electrical conductivity can be estimated from the shape of the band. The phonon and infrared spectra were also determined in order to investigate the vibration mode of molecule in the crystals
Differential Expression of Osteogenic Differentiation in Human Umbilical Cord Wharton’s Jelly-Derived Mesenchymal Stem Cells Treated with Demineralized Bone
Authors: Dhitiseith D. , Honsawek S.
Published: March 2009

Mesenchymal stem cells are multipotential cells capable of differentiating into osteoblasts, chondrocytes, adipocytes, tenocytes, and myoblasts. Wharton’s jelly consists of stem cells that are a rich source of primitive multipotent mesenchymal cells. Demineralized bone matrix (DBM) has been widely utilized as a biomaterial to promote new bone formation. We isolate and characterize umbilical cord Wharton’s Jelly-derived mesenchymal stem (UCMS) cells derived from Wharton’s jelly and examine the biological activity of DBM in this cell line. Osteoblast differentiation of the UCMS cells was determined using alkaline phosphatase (ALP) activity assay. To examine differential gene expression during osteogenic differentiation, total RNA was isolated from UCMS cells in the absence or presence of DBM on day7 and analyzed using osteogenesis cDNA gene array. The selected genes were verified using reverse transcriptase-polymerase chain reaction (RT-PCR) analyses. Wharton’s jelly derived cells could differentiate along an osteogenic lineage after treatment of DBM. The ALP activity assay showed that human UCMS cells could differentiate into osteogenic lineage. Gene expression of human UCMS cells treated with DBM for 7 days was analyzed by using cDNA array and RT-PCR analyses. We found that expression of RUNX2 and SMAD2 was upregulated whereas SMAD7 expression was downregulated as confirmed by RT-PCR. UCMS cells from a Wharton’s jelly of human umbilical cord could express osteogenesis genes for treatment with DBM. Wharton’s jelly from umbilical cord is a new source of mesenchymal stem cells that are readily available for application to bone tissue engineering.
Cholesteryl Cetyl Carbonate as a Smart Material for Drug Delivery Application
Authors: Aeinlang N. , Srichana T. , Songkro S.
Published: March 2009

Cholesteryl cetyl carbonate (CCC) was synthesized from cetyl alcohol and cholesteryl chloroformate. Cholesteryl cetyl carbonate mixture (CCCM) was obtained from the reaction. CCCM was purified by liquid-liquid extraction and flash column chromatography. Thermotropic liquid crystal was formed in both pure CCC and CCCM. CCCM is composed of cholesterol, cetyl alcohol and CCC (30:20:50, weight ratio). FTIR and NMR were employed to confirm the functional groups of CCC. Thermal properties of CCC were determined by DSC and polarized light microscope. The phase transition from solid crystal to smectic appears at 42 °C, smectic to nematic appears at 54 °C and nematic to isotropic liquid appears at 73 °C. Indomethacin (IDM) could be incorporated into CCC and properties of CCC-IDM mixture stayed as liquid crystalline phase.
Preparation and Drug Release Studies of Chitosan/Methoxy Poly(Ethylene Glycol)-b-Poly(D,L-Lactide-co-Glycolide) Nanocomposite Films for Use as Controlled Release Drug Delivery
Authors: Niamsa N. , Srisa-ard M. , Srisuwan Y. , Kotsaeng N. , Baimark Y. , Narkkong N. , Simchuer W.
Published: March 2009

Nanocomposite chitosan-based films incorporated with drug-loaded methoxy poly(ethylene glycol)-b-poly(D,L-lactide-co-glycolide) diblock copolymers (MPEG-b-PDLLG) nanoparticles were prepared by forming drug-loaded nanoparticles in chitosan solution before suspension-solution film casting. Salicylic acid was used as a poorly-water soluble model drug. The nanocomposite films with DLL/G ratios of 100/0 and 85/15 mol% and chitosan/diblock copolymer/drug ratios of 80/1/1, 80/2/2 and 80/4/4 (w/w) were prepared and investigated. The sizes of drug-loaded nanoparticles into the chitosan films were approximate or less than 100 nm. Nanopores were observed in the resulted chitosan films incorporated with drug-loaded nanoparticles when the diblock copolymer ratio was increased up to 2. Number and size of the nanopores increased as increasing the diblock copolymer ratio. Only the nanocomposite films with chitosan/diblock copolymer/drug ratio of 80/1/1 (w/w) showed slower drug release than the chitosan film.
Preparation and Characterization of Poly(D,L-Lactide) and Silk Fibroin Nanocomposite Microparticles for Potential Use in Tissue Engineering
Authors: Kotsaeng N. , Srisuwan Y. , Baimark Y. , Narkkong N. , Simchuer W.
Published: March 2009

Nanocomposite poly(D,L-lactide) (PDLL)-based microparticles containing silk fibroin (SF) nanoparticles were prepared by oil-in-water emulsification solvent evaporation technique of PDLL/SF nanocomposite. The PDLL/SF nanocomposite was obtained from nanoprecipitating SF into PDLL solution in acetone before dried in vacuum oven. The nanocomposite microparticles with PDLL/SF ratios of 20/1, 10/1 and 5/1 (w/w) were prepared and investigated. Interactions between PDLL and SF of microparticles can be observed from FT-IR and thermogravimetric results. Sizes of the SF nanoparticles and the nanocomposite microparticles from SEM micrographs were in the ranges of 50-500 nm and 50-200 µm, respectively. The sizes of SF nanoparticles and nanocomposite microparticles increased as increasing the SF ratio. Surface roughness of the resulted microparticles also increased with the SF ratio.
Investigation of the Strain Hardening and Bauschinger Effect of Low and High Strength Steel Application in Drawbead-Tester by Experiment and Numerical Simulation
Authors: Sirivedin K. , Krueger K. , Thoms V. , Suesse Dietmar , Mueller Roland , Schatz M.
Published: March 2009

The research is aimed to investigate Bauschinger effect and strain hardening by the application of drawbead-tester. Generally, the drawbead is used to control the material flow into the die cavity in sheet metal forming process. When the material is flowing into the drawbead, it may cause the development of strain hardening and/or Bauschinger effect. This work consists of two main equipment particularly developed for the experiments. They are drawbead-tester and three-point bending device. The drawbead-tester provides the possibility to integrate the optical in-process strain analysis system. Whereas the sheet metal was being formed in the drawbead, the local strain of the sheet metal was evaluated. At the same time, the drawbead restraining and holding forces were measured. The three point bending device and numerical simulation method are used to investigate the Bauschinger effect. In the experiment, the cyclic bending forces were measured and compared with the result obtained by numerical simulation.
Effect of Calcination Temperature on Phase and Morphology of Sol-Gel Derived PZTN Powders
Authors: Sangsubun Chontira , Watcharapasorn Anucha , Jiansirisomboon Sukanda
Published: March 2009

Niobium doped PZT (PZTN) powder was prepared by a triol-sol-gel method from a mixture of lead (II) acetate trihydrate, 1,1,1-tris (hydroxymethyl), acetylacetone, titanium (IV) isopropoxide, zirconium (IV) propoxide and niobium (V) ethoxide and calcined at temperature ranging from 300-600oC for 2 h and 600oC for 4 h with a heating/cooling rate of 5oC/min. Thermal characteristics of the PZTN powders were studied using thermogravimetric/differential thermal analyses (TG/DTA). Phase formation in the powder was determined using X-ray diffraction analysis (XRD). Morphology of the PZTN powder was investigated by a scanning electron microscopy (SEM) and transmission electron microscopy (TEM). High purity perovskite structure of PZTN powder with a rhombohedral structure and a crystallite size 38 nm was obtained at the temperature of 600oC for 4 h dwell time. Well separated particles with uniform particle size distribution within 10-50 nm were also observed by TEM.
Synthesis and Characterization of Degradable Poly(Ethylene Terephthalate-co-Lactic Acid) and its Blends
Authors: Sriromreun P. , Opaprakasit Mantana , Petchsuk Atitsa , Opaprakasit Pakorn
Published: March 2009

Because of their respective advantages, the combination of good material properties of poly(ethylene terephthalate) (PET) and degradability of polylactic acid (PLA) is researched as degradable copolymer for packaging and agricultural applications. Poly(ethylene terephthalate-co-lactic acid) (PET-co-PLA) has been synthesized by employing polycondensation of mixtures of dimethyl terephthalate (DMT), lactic acid (LA) and ethylene glycol (EG), using tin(II) octoate as a catalyst. A chain-extending reagent, hexamethylene diisocyanate (HMDI), was then used in the subsequent step to increase the chain length of the copolymer and improve its mechanical properties for suitable applications. The chemical structure and molecular weight of the copolymers were investigated by FTIR, NMR, and DSC. NMR results indicated the incorporation of lactic acid and PET units in the copolymer chain. Additionally, blends of the resulting copolymer with commercially-available PLA were studied. The blend miscibility was examined by DSC and FTIR spectroscopy.
InGaPN/GaP Lattice-Matched Single Quantum Wells on GaP (001) Grown by MOVPE
Authors: Kaewket D. , Sanorpim S. , Tungasmita Sukkaneste , Katayama R. , Onabe Kentaro
Published: March 2009

Highly luminescence lattice-matched InxGa1-xP1-yNy/GaP single quantum wells (SQWs) on GaP (001) substrates were successfully grown by metalorganic vapor phase epitaxy (MOVPE). High-resolution X-ray diffraction measurements established that the lattice-matched InxGa1-xP1-yNy/GaP SQWs with various In (x = 0.050, 0.080, 0.135) and N (y = 0.025, 0.048, 0.071) contents were realized with excellent crystal quality and fairly flat interfaces. The results of photoluminescence (PL) and PL-excitation (PLE) showed the strong visible light emission (yellow to red emission) from the SQWs. With increasing In and N contents, the PL peak position and the PLE absorption edge exhibited the red-shift to lower energy, indicating the lowering of the InGaPN conduction band edge. The conduction band offset (∆Ec) of the InGaAPN/GaP quantum structure was estimated to be as high as 270 to 480 meV, which depends on the In and N contents in the well. Our results demonstrate that this novel InGaPN/GaP SQW system appropriates for the fabrication of light-emitting and laser diodes.
Ammonothermal Preparation of Barium Zirconate Fine Powders
Authors: Wannapaiboon S. , Rujiwatra A.
Published: March 2009

Barium zirconate fine powders of pure cubic phase were readily prepared from the reactions between BaCl22H2O and ZrOCl28H2O under ammonothermal conditions at a very low temperature of 130oC as the lowest. KOH concentration was important in determining phase formation and particle morphology. Reaction temperature and time showed influences on the evolution of particle morphology and aggregation formation, respectively. Sizes of the primary particles critically depended on the BaII:ZrIV mole ratio. Phase formation mechanism is suggested.
A Study of the Effects of Processing Conditions on Mechanical Properties of Polypropylene/Multiwall Carbon Nanotube Nanocomposites Using Design of Experiments
Authors: Duangphattra N. , Aramphongphun C.
Published: March 2009

This research work studies the effects of processing conditions on mechanical properties of polymer nanocomposites. Polypropylene (PP) nanocomposites reinforced with 0.5 and 2.5 %wt multiwall carbon nanotubes (MWCNTs) were prepared via melt compounding and formed by injection molding. 2k Full Factorial design was used to plan the experiments and determine the influences of the processing conditions on mechanical properties and carbon nanotube dispersion in the nanocomposites. These conditions consist of five factors: (a) %wt content of MWCNTs (0.5 and 2.5 %wt), (b) barrel temperature (190 and 220°C), (c) injection velocity (25 and 45 mm/sec), (d) screw rotational speed (75 and 227 rpm) and (e) holding pressure (45 and 65 bar) while injection pressure and cooling time were set at 75 bar and 50 sec, respectively, for all conditions. The samples were examined by Young’s modulus and tensile strength using a Universal Testing Machine (UTM). In addition, Scanning Electron Microscopy (SEM) was applied to study the dispersion of carbon nanotubes in the nanocomposites. The results showed that PP/MWCNT nanocomposites had Young’s modulus of 1,740 MPa and tensile strength of 34.5 MPa while original PP had 1,450 MPa and 28 MPa, respectively. Therefore, the mechanical properties were improved significantly with the content of MWCNTs. Full Factorial experiments investigate that significant factors are %wt, barrel temperature, injection velocity, and screw rotational speed. Moreover, SEM showed that a high content of MWCNTs led to a highly oriented skin layer with well-dispersed MWCNTs.
Fragrant Finishing of Cotton Fabric Using β-Cyclodextrin
Authors: Nakpathom Monthon , Somboon Buppha , Changpradit S.
Published: March 2009

The goal of the current research is the development of an approach that anchors b-cyclodextrin (b-CD) and vanillin fragrance to cotton fabrics simultaneously using traditional pad-dry-cure and pad-dry-batch processes. 2-hydroxypropyl-b-cyclodextrin (HP-b-CD) was mixed with vanillin in water at room temperature and the resultant complex was then applied on the fabric with the use of two crosslinking agents, i.e. glyoxal and a commercial CIBA Knittex® FA CONC. The effects of the amount of HP-b-CD and the type of crosslinking agents on the amount of vanillin deposited on the fabric and its release rate were investigated using UV spectrophotometry.
Use of Hydroxypropylmethylcellulose as Thermo-Responsive Flocculant in Skim Natural Rubber Latex
Authors: Moonprasith N. , Loykulnant S. , Kongkaew C.
Published: March 2009

To recover residual rubber from skim natural rubber (SNR) latex, the effective and environmentally friendly methodology developed based on using hydroxypropylmethylcellulose (HPMC) as a thermo-responsive flocculant. The SNR particles could be completely separated to form high concentrated latex as cream phase within only 5 hours. Almost 100% of SNR was recovered when using HPMC 0.7%w/w. Quality of SNR obtained from this technique was higher and color of it was lighter than SNR obtained from the conventional method. HPMC could be easily precipitated from the serum phase by heating the serum phase at about 70 °C. The cloud point and the precipitation point of HPMC were affected by the additions of α-D-glucose, sn-phosphatidyl chloride and inorganic salts. It was found that reduction of the cloud point and the precipitation point of HPMC also depended on both concentration and type of cations and anions of inorganic salts.
Study of Organic Modification for SrAl2O4:Eu2+, Dy3+ Phosphors
Authors: Lü Xing Dong , Liu Xiao Hua , Gai Guo Sheng
Published: March 2009

Methylaminopropyltrimethoxysilane (MAPS) coupling agent was used to pre-modify SrAl2O4:Eu2+, Dy3+ phosphors, and then graft methylmethacrylate (MMA) on SrAl2O4:Eu2+, Dy3+ phosphors. IR, SEM and TEM measurements showed that there is an organic encapsulation film composed of silane modified poly(methylmethacrylate) (PMMA) on phosphor surface. This organic film encapsulated on phosphor surface like dense reticulation with a thickness of 20-30 nm. The water resistance and oil absorption measurements and persistent luminescent properties showed that after being encapsulated, SrAl2O4:Eu2+, Dy3+ phosphors has much better water resistance and lower oil absorption with little loss of persistent phosphorescence. The emission intensity and afterglow lifetime of the encapsulated phosphors were reduced to 93% and 95% of the originals, respectively.
Application of Silica Fume in China
Authors: Liu Xiao Hua , Lv Xing Dong , Fu Jian Xia , Peng Peng , Gai Guo Sheng
Published: March 2009

Silica fume is the dust recovered from the smoke released while smelting Si or Si-Fe alloy. The papers gives an overview of silica fume application in concrete, refractory, metallurgy and cement in China, along with some projects as examples; To contrast the situation at abroad, the producing, application, and price of silica fume in China was analyzed, and base on this predicted the future market. It is significant to promote deep research and application for silica fume.
Leaching Mineral Elements from Chinese Maifan-Stone
Authors: Liu Xiao Hua , Fu Jian Xia , Li Li , Lv Xing Dong , Peng Peng , Gai Guo Sheng
Published: March 2009

Chinese maifan-stone (CMS) is Chinese traditional mineral medicine, in which there are lots of soluble mineral elements. In this paper static soaping to leach mineral elements and dry or wet gringding maifan-stone simultaneously leaching mineral elements was studied. The result shows that: much more mineral elements were leached from Maifan-stone by the method that wet vibrating mill than by the method that soaking fine Maifan-stone after dry-milling. And the factors influencing on the mineral concentration such as milling time and solid/liquid mass ratio were investigated. Furthermore, the possibility of wet-milling simultaneously to leaching mineral elements from Maifan-stone to industrialization was analyzed, and pointed out that it has good industrialization foreground.