bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Sodium Montmorillonite Modified by Diallylmethyl Alkyl Ammonium Bromide
Authors: Gao Dang Ge , Ma Jian Zhong , Lü Bin , Guo Hai Qing
Published: August 2010

A series of diallyl methyl alkyl ammonium bromide(CCx, X is alkyl’s chain length，represent 12，14，16 and 18 respectively) was synthesized via two step. Monomer was determined by element analysis，NMR，and FT-IR. Organic montmorillonite was prepared by sodium montmorillonite and CCx as intercalating agent. Montmorillonite modified with CCx (CCx-MMT) was indicated by XRD, FT-IR and thermogravimetric analysis (TGA).The XRD results showed that a series of CCx could intercalate into the clay interlayer. XRD and TGA results show that the d spacing of the CCx-MMT was deviated from the linear relationship with TGA organic composition. FT-IR results indicated that the water absorption on the surface of CCx-MMT was effectively restricted and the hydrophobic was increased dramatically. The variety peak intensity at 2924 and 2854cm−1 was consistent with content of organic fraction in CCx-MMT.
Influence of Silicon on Interface Reaction during Aluminium-Silicon Carbide Bonding
Authors: Sozhamannan G.G. , Prabu S. Balasivanandha
Published: August 2010

The effects of Si on the interfacial characteristics of Al-6.25 Si alloy/SiC and Al-11.12 Si alloy / SiC were investigated. The different compositions of aluminium and silicon carbide samples were prepared at various processing temperatures with constant holding time. The characteristics of interface between Al alloy and SiC were evaluated using tensile test and microhardness test. The interface morphologies were evaluated using scanning electron microscope and energy dispersive spectroscopy. The results shown that the interface fracture strength and microhardness values increased at the interface when Si concentration levels were increased.
Interfacial Property between Graphite/Epoxy Laminate and MWNTs/Polymer Nanocomposites
Authors: Yeh Meng Kao , Lai Yun Yu
Published: August 2010

The interfacial property between graphite/epoxy laminate and multi-walled carbon nanotubes (MWNTs)/polymer nanocomposites was investigated. For the graphite/epoxy laminate, the fiber orientations were varied. For the MWNTs/polymer nanocomposites, the epoxy resins were used as the matrix material and the MWNTs were used as the reinforcement. The weight percentage of MWNTs in the MWNTs/polymer nanocomposites beam specimen was varied. The graphite/epoxy laminate and the MWNTs/polymer nanocomposite beam were glued together by epoxy to make the test specimens. To determine the interfacial property, the end notch flexure (ENF) method was used, and the specimen was placed in a three-point bending test to evaluate the critical strain energy release rate Gc. In analysis, the finite element method was used to obtain the numerical values of the critical strain energy release rate Gc and compared with the experimental ones.
Multifunctional Braided Composite Rods for Civil Engineering Applications
Authors: Zdraveva Emilijia , Gonilho-Pereira Cristiana , Sousa Fangueiro Raul Manuel Esteves , Lanceros-Méndez Senentxu , Jalali Saíd , Araújo M.
Published: August 2010

This paper presents the development of a braided reinforced composite rod (BCR) able to both reinforce and monitor the stress state of concrete elements. Carbon fibers have been used as sensing and reinforcing material along with glass fiber. Various composites rods have been produced using an author patented technique based on a modified conventional braiding machine. The materials investigated were prepared with different carbon fiber content as follows: BCR2 (77% glass/23% carbon fiber), BCR3 (53% glass/47% carbon fiber), BCR4 (100% carbon fiber). BCRs have been tested under bending while the variation of the electrical resistance was simultaneously monitored. The correlations obtained between deformation and electrical resistance show the suitability of the rods to be used as sensors. The fractional resistance change versus strain plots show that the gage factor increases with decreasing carbon fiber content.
Periodicity of Piezoelectric Ceramic Rods on Properties of 1-3 Type Cement Based Piezoelectric Composite
Authors: Xu Dong Yu , Huang Shi Feng , Ju Chao , Zhang Zong Zhen , Cheng Xin , Jiang Min Hua
Published: August 2010

Periodic and non-periodic 1-3 type cement based piezoelectric composites were fabricated by cut and filling technique, using P(MN)ZT ceramic as functional material and cement as matrix. The influences of periodicity of piezoelectric ceramic rods in the composites on electrical properties of all the composites were discussed. The results show that the non-periodic composites have larger dielectric factor and piezoelectric strain constant than those of the periodic composite. The impedance-frequency spectra analysis indicates that the non-periodic arrangement of ceramic rods can effectively restrict the lateral structural mode of the composite, accordingly reduces the coupling resonant between the thickness resonant mode and lateral resonant mode. The thickness electromechanical coupling coefficient of non-periodic composites is larger than that of the periodic composite. With increasing the non-periodic level of P(MN)ZT ceramic in the composites, the mechanical quality factor of the composites increases gradually. Therefore, 1-3 type cement based piezoelectric composites with different special abilities can be obtained by varying the periodic arrangement of P(MN)ZT ceramic rods in the composites.
NIR Emission Analysis of Er3+/Yb3+ and Er3+/ Tm3+ Ions Doped Zinc lithium Boro Tellurite (ZLiBT) Glasses for Optical Fiber Amplification
Authors: Sudhakar Reddy B. , Vemasevana Raju K. , Sailaja S. , Nageswara Raju C. , Sreekantha Reddy D.
Published: August 2010

This paper reports on the development and the near infra-red emission(NIR) analysis of Er3+/Yb3+ and Er3+/ Tm3+ ions doped TeO2 - B2O3 – ZnO - Li2O glasses for tunable laser and optical fiber amplification. From the measured near infra-red emission spectra of Er3+/Yb3+, Er3+/Tm3+: ZLiBT glasses have revealed the prominent near infra-red emission bands at 1532 nm (4I13/2 → 4I15/2), with an excitation wavelength of λexci = 515 nm (Ar+ ion laser). The full width at half-maxima (FWHM) values are also estimated from the measured near infra-red emission spectra of the glasses. Based on spectral results, broad near infra-red emissions should have potential applications in broadly tunable laser sources and broad band optical amplification at low-loss telecommunication windows.
Properties of Biodegradable Poly(lactic acid)/Poly(butylene adipate-co-terephthalate)/Calcium Carbonate Composites
Authors: Teamsinsungvon Arpaporn , Ruksakulpiwat Yupaporn , Jarukumjorn Kasama
Published: August 2010

Poly (lactic acid) (PLA), a biodegradable polyester, derived from renewable resources has been widely used in biomedical and packaging applications. However, the shortcomings for using PLA including its processing instability, low melt viscosity and low flexibility limited its applications. To overcome these shortcomings, poly (butylene adipate-co-terephthalate) (PBAT) was blended with PLA to improve ductility of PLA. However, PLA and PBAT are incompatible. Maleic anhydride grafted PLA (PLA-g-MA) was used to enhance the compatibility of the blends. Moreover, the blend of PLA and PBAT exhibited higher elongation at break but lower tensile strength and Young’s modulus than the pure PLA due to the addition of a ductile phase. Therefore, the addition of calcium carbonate (CaCO3) to PLA/PBAT blends led to achieve balanced properties of the blends. In this study, PLA/PBAT blends and PLA/PBAT/CaCO3 composites were prepared by an internal mixer. PLA-g-MA was as a compatibilizer. Mechanical properties and rheological properties of the blend and composites were investigated. In addition, morphologies of PLA/PBAT blend and their composites were observed by a scanning electron microscope (SEM). The incorporation of PBAT gave rise to remarkable improvement in elongation at break and impact strength of PLA. Tensile strength of PLA/PBAT blend was enhanced by adding PLA-g-MA. With increasing CaCO3 content, Young’s modulus of the composites increased while tensile strength and elongation at break decreased.
Study on Erosion Wear Behavior of PDCPD/MMT Nanocomposite
Authors: Pan Bing Li , Xing Ya Li , Zhang Chun Fei , Zhang Yu Qing
Published: August 2010

Polydicyclopentadiene (PDCPD)/montmorillonite Clay (MMT) nanocomposites were synthesized through reaction injection molding with a Gusmer-Decker machine by in situ polymerization. The results of X-ray diffraction (XRD) diagrams of the nanocomposites showed that MMT were completely exfoliated within the range of 0.25% to 4% MMT. The erosion wear behaviors of PDCPD/MMT nanocomposites were studied using an MCF-30 water and sand erosion wear tester. The worn surface of PDCPD/MMT nanocomposites was exami-ned with a scanning electron microscope (SEM) and the wear mechanism was discussed.It was found that when the content of MMT is 0.25%, the erosion rate of nanocompositesreach the minimum; the erosion rate of nanocomposites increases with the increase of MMT content compared with neat PDCPD. The important wear mechanism of neat PDCPD was tearing and ploughing-cutting, And the results showed that wear mechanism of PDCPD/MMT nanocomposites was dominated by ploughing-cutting, with the increase of MMT the severe mechanical cutting, fatigue wear and slight brittle rupture appear. PDCPD/MMT nanocomposites with a lower content of MMT were thus a promising structural material candidate for engineering application.
Study on Impact Fractures of Adhesively Bonded Composite Joints
Authors: Cho Jae Ung , Kinloch Anthony , Blackman Bamber , Rodriguez Sanchez F.S.
Published: August 2010

From the impact experiment for the nonlinear plastic behavior with the dynamically loaded adhesively-bonded TDCB specimens, there is the range of load from 1 to 2 kN or pin displacement from 4 to 10 mm for the most part in case of the impact rates 1, 2.5, 5, 7.5 and 12.5m/s. There is also the range of energy from 5 to 10 J or energy release rate(fracture energy) from 3000 to 6000 J/m2 for the most part in case of all impact rates. The fracture energy on automotive adhesive joints can be estimated by using the fracture toughness, GIC, experimental results under high rates of loading in this study. The key fracture mechanics parameter, namely the fracture energy, GIC, was ascertained as a function of test rate and may be used to assess and model the joint performance.
Synthesis of Ferrite Nanoparticle and Ferrite-Gold Heterostructures
Authors: Lin Fang Hsin , Doong Reuy An
Published: August 2010

The synthesis of uniform and monodispersed magnetic and optical nanocrystals has received much attention in recent years due to the size-dependent physicochemical properties. In this study, we have demonstrated a general approach for the synthesis of size-tunable ferrite and gold nanocrystals and their nanocomposite. The monodispersed magnetite nanocrystals were obtained by thermal decomposition of iron-oleate complex in a high boiling point solvent in presence of oleylamine and oleic acid. The size of magnetite nanocrystal can be tuned from 7 – 11nm by changing the amount of iron-oleate complex. The other key parameters such as temperature, amount of capping agents, types of solvent were also discussed. This synthetic procedure could also apply to synthesis other type of ferrite nanocrystals. When Mn-acetate was partially substituted for iron-oleate in a 1:2 ratio in the same reaction conditions as in the synthesis of Fe3O4, monodispersed MnFe2O4 nanocrytals with 14nm could be obtained. Except those magnetic nanocrystals, we also synthesized various sizes of monodispersed gold nanocrystals by reducing HAuCl4 in presence of t-butylamine-borane and oleylamine. By varying the reaction temperature, the particle size could be well-tuned from 2nm to 8nm with the characteristic surface plasmon absorption between 510 and 520 nm. For Fe3O4/Au composite, it was prepared via the decomposition of iron-oleate over the surface of the Au nanoparticles. The mean size of the Fe3O4/Au nanocomposite was ∼17 nm which shows a saturation magnetization of 46.92 emu/g and absorption peak at 512nm. These composites with both magnetic and optical properties would make them very promising in the fields of biomedine and environment.
The Cosserat Elasticity Constants of Circular Cell Honeycombs
Authors: Chung Jae Ung , Waas Anthony M.
Published: August 2010

Closed form expressions for the Cosserat constants for circular cell honeycombs are derived using a combination of non-dimensional analysis and numerical analysis. The expressions for the four in-plane Cosserat compliances, which are the plane strain bulk compliance, the shear compliance, the micropolar compliance and the bending compliance are derived in terms of the cell size, cell thickness and the linear elastic properties of the cell wall material. Numerical analyses are performed to verify the accuracy of the derived constants by considering different combinations of geometric parameters and different numbers of cells for the honeycombs. It is shown that the closed form expressions are an accurate representation of the Cosserat constants of circular cell honeycombs.
The Effect of Visible Light-Activated TiO2 Thin Film on Nosocomial Pathogens
Authors: Chang Chen Yu , Hsu Shih Kuang , Chang Chen Jung , Shieh Yaw Nan , Chang Ching Lan , Lo Hsueh Hsia
Published: August 2010

Many methods had been developed to disinfect or sterilize the medical equipment or hospital environment for controlling the spread of nosocomial pathogens. This study was aimed to evaluate the effect of titanium dioxide (TiO2) thin film on preventing nosocomial infection. Firstly, TiO2 thin film was prepared by using the modified impregnation method and further analysis by field-emission scanning electron micrographs and X-ray diffractometer. The nano-size and Anatase crystal structure were confirmed. By using visible light activation of TiO2 thin film for 30 min, the inhibition of Enterococcus faecalis, Streptococcus bovis, Streptococcus agalactiae, and Staphylococcus aureus by TiO2 thin film treatment were 27.4%, 73.3%, 56.6%, and 9.4%, respectively. In addition, several important Gram negative bacteria causing nosocomial infection were also investigated. The inhibition rate of Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli were 32.5%, 31.3%, and 22.4%, respectively. The results revealed that TiO2 thin film activated by visible light may be useful for decreasing nosocomial infection.
Comparative Bioavailability Studies of Two Indomethacin Controlled Release Formulations in Healthy Albino Sheep's
Authors: Gowda D.V. , Rajesh N. , Shiva Kumar H.G. , Siddaramaiah
Published: August 2010

The purpose of the present study was to compare the in vitro release and to findout the bioavailability of a 75 mg indomethacin capsule (Microcid®SR - reference - product A) was equivalent to optimized formulation (indomethacin loaded microspheres – test – product B). Indomethacin (IM) loaded carnauba wax fat microspheres were prepared by using meltable emulsified dispersion cooling induced solidification technique utilizing a wetting agent. Solid, discrete, reproducible free flowing microspheres were prepared. The yield of the microspheres was up to 92%, having smooth surfaces, with free flowing and good packing properties, angle of repose, % Carr’s index and tapped density values were within the limit. More than 98.0% of the isolated spherical microspheres were in the particle size range of 1135 - 1360 mm were confirmed by scanning electron microscopy (SEM). The drug loaded in microspheres was stable and compatible, as confirmed by DSC and FTIR studies. A single dose, randomized, complete cross over study of IM (75 mg) microspheres was carried out on 10 healthy male and female Albino sheep’s under fasting conditions. The plasma was separated and the concentrations of IM were determined by HPLC-UV method. Plasma IM concentrations and other pharmacokinetic parameters obtained were statistically analyzed. Based on this study, is it possible to conclude that drug loaded microspheres and Microcid®SR capsule are bioequivalent in terms of the rate and extent of absorption.
Nanoceramics Composite Biomaterials in the Calcium Carbonate-Hydroxyapatite System
Authors: Goldberg Margarita , Smirnov Valeriy , Kucev Sergey , Sergeeva Natalia , Sviridova Irina , Kirsanova Valentina , Akhmedova Syraia , Barinov Sergey
Published: August 2010

Composite powders in the calcium carbonate (CC) – hydroxyapatite (HA) system with carbonate content up to 50 wt. % were synthesized by the precipitation from aqueous solution and characterized in detail. Specific area of the powders decreases with an increase in carbonate content due to appearance of large elongated CC crystals of about 0,5 micrometer size. The use of highly active to sintering nanodisperse powders resulted in lowering of sintering temperature below 7200C, preventing thermal decomposition. Ceramics of about 20 wt.% carbonate content revealed the highest strength of about 77 MPa, having the grain size of about 100 nm. According to in vitro testing, the materials are non toxic for human fibroblast cells.
Processing and Characterization of Tissue Adhesive from Rice Starch Nanocomposites
Authors: Puntuwat Watee , Wongsa Sathiya , Poonyawatpornkul Jiraporn , Punyanitya Sittiporn , Raksujarit Anirut
Published: August 2010

The objective of this work is make tissue adhesives agent from Thai rice starch, then test the final products for scientific and medical properties following the laws of Thai health ministry, to demonstrate that this product can be used safely, as same as the standard product. The principal raw material is pharmaceutical grade, Thai rice starch powder. The additives are hydroxyapatite (HA) nanopowder, carboxymethylcellulose, lactic acid, gelatin, polyvinylalcohol and glycerol. All materials will be mixed in distilled water under high temperature, and dried into starch tissue adhesives plate hydrogel. The final product will be kept in medical package and sent for sterilization by gamma radiation. These products will be characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD), stability in water, and adhesive bond strength test in wet environment.
Synthesis and Characterization of Silk Fibre Reinforced Cepu Composites
Authors: Swamy T.M. Mruthyunjaya , Gowda Manjula Koregala Sidde , Siddaramaiah  , Lee Joong Hee
Published: August 2010

Composites of silk fibre reinforced chain extended polyurethane (CEPU) was synthesized by the reaction of castor oil with different diisocyanates and glutaric acid as chain extender. The effect of incorporation of silk fibre into neat CEPU on the physico- mechanical properties and thermal behaviours (TGA and DMA) has been investigated. The incorporation of silk fibre into CEPUs resulted in an enhancement of tensile strength and Tg. The effects of biological fluids and salt solution on swelling behavior of CEPU biocomposites were reported.
Key words: Castor oil, silk fibre, composites, polyurethane, DMA, TGA.
Characterizing Interphase Properties in Fiber Reinforced Polymer Composite with Advanced AFM Based Tools
Authors: Wang Si Qun , Nair San Deep , Hurley Donna , Lee Seung Hwan
Published: August 2010

Advanced atomic force microscopy techniques such as contact resonance force microscopy, noncontact mode phase imaging, and scanning thermal microscopy techniques have been used to characterize material properties in the interphase of fiber reinforced polymer composites. With contact resonance force microscopy, the average interphase thickness was found to be (49 ± 5) nm, (64 ± 12) nm, and (139 ± 21) nm for samples containing lyocell fibers in matrix materials consisting of 100 % polypropylene (PP)/0 % maleated polypropylene (MAPP), 95 % PP/5 % MAPP, and 90 % PP/10 % MAPP, respectively. Clear distinctions in modulus values between the fiber, interphase zone, and matrix are clearly visible in modulus images. A gradient of modulus was observed across the interphase region that ranged between the modulus values of fiber and the polymer matrix. Noncontact mode images showed a clear phase difference between the fiber, interphase, and matrix owing to the difference in material properties between the components. Interphase regions were observed to possess higher thermal conductivity than the matrix polymer due to cross-linking within the interphase.
Microstructure Analysis of TaN/Cu Nanocomposite Coatings Deposited by Pulsed DC Magnetron Sputtering
Authors: Elangovan T. , Mangalaraj D. , Prabakar K. , Kuppusami P. , Khan Shabana , Mohandas E.
Published: August 2010

TaN-Cu nanocomposite thin films used as materials for thin-film resistors (TFR) were prepared by magnetron pulsed dc reactive sputtering. Structural and morphological properties of films deposited on (100) Si as a function of nitrogen flow rate and substrate temperature is investigated. With the introduction of N2 gas flow indicated with different phases of nanocrystalline h-Ta, Ta2N, TaN, Ta4N5 and Cu. XRD analysis of the films deposited with increasing substrate temperature at constant flow rate of nitrogen 10 sccm indicated that the nanocrystalline with bi-phasic (fcc-TaN and fcc-Cu). The microstructure of the films was investigated by scanning electron microscopy and high-resolution transmission electron microscopy.
Study on Design and Evaluation Method for Transport Packaging Protection
Authors: Guo Yan Feng , Xu Wen Cai
Published: August 2010

Product-packaging system must survive the environmental hazards experienced during transport and distribution. This paper deals with the design and evaluation method for transport packaging protection. Firstly, just right transport packaging evaluation system is studied and established, which includes four evaluation sub-modules such as packaging reliability, packaging convenience, packaging cost rationality, and environment protection. Then, the improved design method for transport packaging protection with just right transport packaging evaluation system is put forward on the basis of the concept of just right transport packaging and the requirement of environment protection. The improved design and evaluation method can effectively predict and control over-packaging and under-packaging, and is useful to realize just right transport packaging. The research work would provide instruction for the design and evaluation of transport packaging protection of product.
Temperature Dependent Electrical Properties of Conductive Composites (Behavior at Cryogenic Temperature and High Temperatures)
Authors: Rahaman M. , Chaki Tapan Kumar , Khastgir D.
Published: August 2010

Extrinsically conductive polymer composites can be developed by incorporation of conductive filler in suitable polymer matrix. The formation of conductive network in insulating matrix due to filler aggregation at and above percolation is responsible for electrical conductivity of such composites. The present investigation deals with effect of temperature on conductive composites made from different blends of Ethylene-Vinyl copolymer (EVA) and Acrylonitrile-Butadiene copolymer (NBR) filled with particulate carbon filler. The electrical properties of these composites depend on blend composition and filler loading. High temperature (303-393K) DC-resistivity against temperature for EVA and EVA blends composites show positive coefficient of temperature (PCT effect) followed by negative coefficient of temperature (NCT effect) thus passing through a maxima which corresponds to crystalline melting temperature(~348K) of EVA phase. Further the variation of conductivity during heating cooling cycle does not coincides and leads to some kind of thermal hysteresis due to change in conductive network structure. However in low temperature region (10-300K), the resistivity is found to increase with decrease in temperature (NCT effect) and hysteresis effect is also marginal compared to that observed in high temperature region. This difference resistivity/conductivity vs temperature behavior in two different temperature zones suggests that different two mechanisms are operative in the system.
Improvement in Etching Factor of Micro Patterns by Controlling Residual Stress of Copper Thin Foil
Authors: Lee Hyo Soo , Lee Hai Joong
Published: August 2010

The effectiveness of residual stress on forming copper patterns of printed circuit board was investigated during applied thermal conditions. Generally, the electrolytic copper foil showed a compressive residual stress about -55~-60MPa as received, which easily caused to form copper patterns irregularly when the pattern was etched finely. The compressive residual stress was relaxed with applying heat-treatment for a few hours. However, we observed that the compressed residual stress of copper foil tended to be relaxed, constant, and compressed again during heat-treatment process, which is mainly considered as that the grain of copper is grown restrictively within a Cu thin foil layer. We suggested a quantitative method for controlling grain size, grain distribution and relaxing stress of copper foil, which was very helpful for increasing an etching factor to decrease pattern width.
Improvement of Mechanical Properties of Semi-Solid Alloys by ECAP Processing
Authors: Nomura Fumiya , Matsuba Takuya , Tanaka Tatsuya , Imaida Yutaka
Published: August 2010

Recently, semi-solid processing is paid to attention in the field of the light alloys. By this method, it is improved ductility and fatigue strength. Although, because of those mechanical properties of the elongation and toughness is not excellent, the range that can be the application to parts is limited. On the other hand, it is reported that grain refinements cause improvement of ductility and appearance of super plasticity. Then, Equal-Channel Angular Pressing (ECAP) method is reported to be effective to the sample making of a bulk and ultra fine grain in various alloys in recent years. In this study, it tried to improve ductility and durability due to making ultra fine grain in AC4CH alloys by the ECAP method, and the influence of ECAP processing on the mechanical property of AC4CH was investigated. As the result, the ductility of AC4CH has improved by ECAP processing. However, the tensile strength of AC4CH declined along with the increase in the number of passes. So, for the purpose of additional improvement of tensile strength, ECAP-Back Pressure (ECAP-BP) method that was reported to be more effective for grain refinements than ECAP method was applied to semi-solid AC4CH and compared with ECAP method. As the result, the tensile strength of AC4CH was maintained by use of ECAP-BP. Moreover, both ductility and toughness of that have been also improved.
Mechanical Property Evaluation of IRM®/Chitosan Fiber Composite Temporary Filling Material
Authors: Lin Jia Horng , Lu Po Ching , Lu Chao Tsang , Chao Tzu Hsuan , Lou Ching Wen
Published: August 2010

The temporary filling material seals up the tooth cavity so as to prevent bacterial leakage and the second infection in the root-end treatment. Chitosan is biodegradable, bio-resorbable, non-toxic, and antibiotic. In this study, chitosan fiber is used to enhance the temporary filling material compressive strength and the tooth bite force. IRM® is reinforced by the 2, 4 and 6 wt% chitosan fibers, respectively. And after solidified the IRM®/ Chitosan fiber composite temporary filling material was obtained. Then setting time, solution test, compressive strength and dye micro-leakage of IRM®/ Chitosan fiber composite temporary filling material were be evaluated.
In result, maximum compressive strength of IRM®/ Chitosan fiber composite temporary filling material was obviously increased 200 N than IRM® matrix. As to the micro-leakage test, no trace of leakage was found on the 7th day. Consequently, IRM®/ Chitosan fiber composite temporary filling material can be a good candidate in the short-term dental clinical surgery.
Mold Development for Resin Transfer Molding with Dimension Variation and Deformation Compensation
Authors: Dong Chen Song , Lynch Stuart , Li Jun
Published: August 2010

A method for achieving better dimensional control for composites based on deformation compensation in mold design is presented in this paper. The process-induced deformation of a general angled part, i.e. spring-in, was studied statistically to account for the processing-related uncertainties. The part geometry was modified based on the results from the statistical analysis for offsetting the deformation. The modified part geometry was used to design the mold for resin transfer molding and the mold was made by the CNC wire electrical discharge machining (WEDM) process. Five sample parts were fabricated using the mold and the spring-in angles were measured. The results show that the process-induced deformation is significantly reduced through deformation compensation. This method presented in this paper provides an approach to minimizing the overall process-induced deformation of resin transfer molded parts.
Preparation of Functional Low-Cohesive Composite Dressings
Authors: Lou Ching Wen , Lu Chao Tsang , Huang Shih Yu , Lu Po Ching , Huang Chao Chiung , Lin Jia Horng
Published: August 2010

Sodium alginate and Chitosan are common bio-medical dressing material, and drug delivery due to their excellent biocompatibility, biodegradability and non-toxicant. The purpose of dressing aimed at accelerating wound healing. In this study, sodium alginate/Chitosan composite solution composed of Chitosan particles and well-stirred sodium alginate solution. The PLA/cotton nonwoven was the base fabric. The sodium alginate/Chitosan composite solution was later sprayed upon the fabric, so a sodium alginate/Chitosan/PLA/absorbent cotton composite dressing was prepared. Calcium chloride was applied to strengthen the bonding between the sodium alginate/Chitosan solution and the fabric. Mechanical property and SEM of the sodium alginate/Chitosan/PLA/ absorbent cotton composite dressing’ were evaluated.
The Dependence of PET Layer on the Thermal Stability of PET-ITO Substrate for Mobile Electronics
Authors: Lee Hyo Soo , Bang Jae Oh , An Kyong Jun , Jung Seung Boo , Chai Kyoung Hoon
Published: August 2010

The PET-ITO substrate has been usually applied to many flexible applications such as selectively conducting films, flexible printed circuit, display panels, interconnections, terminals, etc., where the PET-ITO substrate has a main role to enhance the performance in the components of touch screen panels, solar cell panels and so on. Today’s flexible technology is issued on forming fine pattern, pattern alignment and mass-productivity on PET-ITO substrates, which is strongly related to thermal shrinkage and expansion of the substrate[1~5]. We investigated in this study the thermo-mechanical behavior of PET-ITO substrate using a thermo-mechanical analyzer (TMA) in order to analyze thermal strain with varying temperature.
FEM Analysis of 1-3 Cement Based Piezoelectric Composites
Authors: Zhang Zong Zhen , Peng Ya Ping , Xu Dong Yu , Cheng Xin
Published: August 2010

The simulating software ANSYS is applied to carry out the coupling analysis of the 1-3 cement based piezoelectric composites. The interior displacement and strain distribution were obtained and discussed. The influences of material parameters such as thickness, relative dielectric constant, Poisson’s ratio and Yang’s modulus on the composites were analyzed based on the FEM model. The results indicate that active strain and displacement of the 1-3 cement based piezoelectric composites is mainly concentrated on the piezoelectric ceramic rods. The performance of the 1-3 cement based piezoelectric composites can be improved efficiently by increasing the thickness, Poisson's ratio, and reducing the Yang's modulus, the relative dielectric constant.
Investigating Particle Effect on Tensile Strength of Particulate Nanocomposites
Authors: Tsai Jia Lin , Lin Yi An
Published: August 2010

This research aims to investigate the effects of particle size, volume fraction and dispersion on the tensile strengths of particulate nanocomposites with an embedded crack. The finite element micromechanical model in conjunction with linear elastic fracture mechanics (LEFM) was used to study the particle effect on the fracture behavior of nanocomposites. Results indicated that the tensile strength of particulate composites increases when the particle size is decreasing, however it can be deduced dramatically by the local aggregation of particles. The simulation results are in good agreement with the experimental observation. In addition, the predictions show that the tensile strength decreases with the increase of volume fraction of nanoparticles. So far, no consistent experimental data can be found to validate the above results and thus further study in this issue is required.
New Approach of Multi Scale Modeling Based on the Hygro-Cosserat Theory for Self Desiccation Deformation of Cement Mortars at Early Age
Authors: Jeong J. , Mounanga P. , RAMEZANI Hamidréza , Bouasker Marwen , Bassir D.
Published: August 2010

In the present paper, we concentrate on the heterogeneous cement mortars and we treat them as Cosserat-based media. The autogenous shrinkage phenomenon at early age (from 1 up to 3 days after mixing) has been analyzed by means of Cosserat theory. The characteristic length scale parameter Lc in this theory helps us to change the size specimen from macro-scale to micro-scale using the theoretical size effect aspects. This methodology is also capable of treating cracks initiation and their appearance in the cementitious matrix surrounding the sand-inclusions, which should occurred inside of the Representative Volume Elementary (RVE) of mortar subjected to self-desiccation shrinkage during hydration at early age. By taking advantage of the Nonlinear Finite Element Analysis (NFEA), the numerical experiments have been performed. The numerical outcomes are well agreed with the experimental observations coming from Scanning Electronic Microscopy (SEM) images. It concludes that the inclusions create not only a hygro stress concentration around the grains but also the number of inclusions should influence the network in cementitous matrix.
Thermo-Mechanical Analysis in W/Cu-Alloy Joints with Different Interlayer Thickness
Authors: Sha Jian Jun , Wang Jing , Gao Xiao Wei
Published: August 2010

Thermo-mechanical analysis for W/Cu-alloy joints with different interlayer thickness of OFHC-Cu was carried out by FEM calculation. The result indicated that the compliant OFHC-Cu can significantly reduce the magnitude and concentration of stress and plastic strain, but a weak influence on the temperature distribution. A comparison was made on the residual stress and plastic strain between the fabrication and operation conditions. It was found that the optimum thickness of OFHC-Cu is 1.0 mm in current analysis conditions.
Transverse Stresses in Antisymmetric Angle Ply Sandwich Plates – Analytical Evaluation of Refined Higher Order Shear Deformation Theories
Authors: Swaminathan K. , Sangwai Govind R.
Published: August 2010

In the present work two higher order computational models with 9 and 12 DOF already available in the literature for which analytical formulations and solutions for the stress analysis not yet reported are considered. In addition to these models, few higher order models and the first order model developed by other investigators are also considered for the evaluation. A simply supported plate subjected to sinusoidal transverse load with SS-2 boundary conditions is considered for the analysis. Solutions are obtained using Navier's technique. Transverse stresses are computed by post processing technique and the accuracy of models in predicting the stresses is evaluated.
Research on the Nanoscale Additives to the Ni(OH)2 Electrodes for High Power Ni/MH Batteries
Authors: Wu Jian Bo , Chen Yao Lin
Published: August 2010

As the positive electrodes of Ni/MH batteries, the Ni(OH)2 Electrodes needs some additives to enhance their high power performance. In this paper, two kinds of nanoscale additives were synthesized and added to the Ni(OH)2 electrodes respectively and the high rate discharge capabilities of both electrodes were investigated. Compared with the Ni(OH)2 electrodes with usual CoO, the electrodes with carbon nanotubes and with nanoscale carbon particles modified onto the surface of Ni(OH)2 spheres both presented much better cycling stability and higher specific capacity when discharged at high current rate. It is suggested that when the nanoscale additives were added to the electrodes, more sufficient conductive networks formed among Ni(OH)2 spheres. The results indicate that the nanoscale materials such as carbon nanotubes and nanoscale carbon particles are desirable additives for high power Ni/MH batteries in addition to usual CoO.
Ru(II) Complex Based Optical Oxygen Sensors
Authors: Milanova Maria , Zaharieva Joana , Anastasova Salzitsa , Todorovsky Dimitar
Published: August 2010

A short review of recent investigations of the authors on the Ru(II)-based optical oxygen sensors is presented focused on the influence of: (i) type of the supporting matrix (SiO2 or polymethylmetacrylate based), (ii) precursors used (tetraethoxysilane, ormosil-type alkoxosilanes, methylmetacrylate, polymethylmetacrylate), (iii) method applied for the matrix synthesis, (iv) method for films deposition (dip- and spin coating), (v) chromophore leaching as a result of storage of the films in potentially aggressive media (water, diluted acidic and basic solutions) and (vi) working environment nature on the: a) films morphology, b) the analytical characteristics of the sensing component (linearity of the Stern-Volmer dependence, sensitivity of the device, reproducibility of the results), c) admissible parameters (pH, temperature) of the working medium. Special attention is paid on the effect of sol-sonication (as a tool against dye microcrystallization). The results obtained permit optimal precursors, sol preparation conditions and coating procedure to be recommended for gas and for dissolved oxygen measurement, respectively. The sonication of the sol ensures a rather significant improvement of the sensor performance. The strong quenching of the chromophore in the case of in-situ polymerization of the methylmetacrylate is observed.The sensing films are successfully applied for oxygen determination in natural lake waters and beer.
An Investigation on Vibration and Thermal Change of High Speed Lathe Processing Using Infrared Thermal Imaging Technique
Authors: Yang Yong Ha , Choi Seung Hyun , Kim Jae Yeol , Cha Yong Hoon
Published: August 2010

Vibrations during lathe machining include vibrations by a sudden clash of a tool against a workpiece as an external excitation, vibrations by irregular tissues of the workpiece, vibrations by regular excitation due to asymmetric torque, and vibrations by bearing defects. Furthermore, machine tools are heated because most of the supplied energy is transformed to heat and becomes the heat source of the machine tool or an internal heat source. In addition, the spindle is one of the largest internal heat sources. The heat distortion of the spindle by this heat source has the most serious effect on the total heat distortion of the machine tool, and the heat distortion of machine tools is the largest cause of the degradation of cutting precision. In order to obtain accurate data about the causes of such vibrations and heat, this study measured the vibrations and thermal changes of each specimen using a vibrometer and an infrared thermography camera.
Application of the Ultrasound-Infrared Thermography Technique for Non-Destructive Evaluation of Defects in Shoe Bonding Parts
Authors: Choi Seung Hyun , Kwac Lee Ku , Kim Jae Yeol
Published: August 2010

The infrared thermography technique is being applied in many areas. Particularly these days, non-destructive inspection and evaluation using the ultrasound-infrared thermography technique are hogging the spotlight in a wide range of study areas. The ultrasound-infrared thermography technique uses the principle that ultrasound waves projected to objects with cracks or defects at connections generate local heat from the defective surface.
In this research, introduce nondestructive evaluation method for total inspection of special shoes applying Ultrasound Infrared thermography Technique. Performance of the proposed method are shown by through thermo-Image. The total inspection system using infrared thermal camera for special shoes, its applicability, and system configuration are introduced.
Terahertz Ray Nondestructive Characterizations in FRP Composites
Authors: Park Je Woong , Im Kwang Hee , Hsu David K. , Chiou Chien Ping , Barnard Daniel J.
Published: August 2010

Recently, terahertz ray imaging has emerged as one of the most promising new powerful nondestructive evaluation (NDE) techniques, and new application systems are under processing development for the area applications.
In this study, a new time-domain spectroscopy system was utilized for detecting and evaluating layup effect and flaw in FRP composite laminates. Extensive experimental measurements in reflection mode were made to map out the T-ray images. Especially in this characterization procedure, we estimated the electromagnetic properties such as the refractive index. Estimates of properties are in good agreement with known data. Furthermore layup effect and flaw of FRP composite laminates were observed in reflection mode and limitations will be discussed in the T-ray processing.
Flammability and Mechanical Properties of Sisal Fiber/Polypropylene Composites: Effect of Combination of Flame Retardants
Authors: Jeencham Rachasit , Suppakarn Nitinat , Jarukumjorn Kasama
Published: August 2010

Ammonium polyphosphate (APP) and zinc borate (Zb), as flame retardants were incorporated into sisal fiber/polypropylene (PP) composites. Ratios of APP to Zb were varied. Maleic anhydride grafted polypropylene (MAPP) was used to improve the interfacial adhesion between polypropylene and fillers. Flammability of the composites was examined using a horizontal burning test, a vertical burning test, and a limiting oxygen index test. Morphology and mechanical properties of the composites were also investigated. The composite containing 30 phr of APP and 10 phr of Zb exhibited better flame retardancy than the composites containing other ratios of APP to Zb. The combination of APP and Zb insignificantly changed mechanical properties of the composites. In addition, SEM micrographs of the composites revealed good distribution of flame retardants and sisal fiber in PP matrix.
All-Fiber Optic Chemical Sensors for Public Safety Monitoring
Authors: Lee Jung Ryul , Yoon Chang Yong , Dhital Dipesh , Yoon Dong-Jin
Published: August 2010

The leakage of toxic or flammable chemical substances that might affect or endanger public safety has always attracted the attention of the researchers to develop a chemical sensor that could prevent any life-threatening incidents. Due to its robust features, hard polymer clad fiber (HPCF) was used in this experiment to develop an all-fiber optical chemical sensor. The outer hard polymer clad was removed by using mechanical method to expose the inner core. The exposure lets contact between the leaked chemical and the core, both with different refractive indices (RI). The change in signal property of the passing light wave occurs at this point and hence can be detected using optical time-domain reflectometer (OTDR). In this way, HPCF was transformed into a fiber optic chemical sensor. OTDR was used as a sensing system that allowed the sensor to detect and localize the leakage of chemical substances in real-time, by measuring the light loss in backscattering light (signal) that was caused due to extraction of chemical on fiber cladding. This light loss is based on leaky wave mode principle. The reliability of the sensor was tested with Benzene, Toluene, Pyridine, Dimethylsulphoxide and several other toxic chemicals. The results showed that the sensor was able to detect the chemicals (in liquid state) and localize the event positioning. With the promising results, the sensor will be further tested with different types of chemicals to optimize the fiber chemical sensing system.
Photorefractive Materials, from Polymer to Hyper-Structured Molecule
Authors: Zhang Li , Shi Jun , Cao Shao Kui
Published: August 2010

A series of amorphous polyphosphazenes containing carbazole-based multifunctional chromophores and two hyper-structured photorefractive molecular glasses with a cyclotriphosphazene core were synthesized. These photorefractive polymers and molecular glasses show low glass transition temperature (20-90oC) and can easily be fabricated into optically transparent films with long-term stability. Results of two-beam-coupling and four-wave-mixing experiments demonstrated that high gain coefficient and diffraction efficiency were achieved at zero electric field for samples fabricated with these materials.
Damage Detection in Composite Cylindrical Multilayered Shells with Delaminations
Authors: Muc Aleksander , Stawiarski Adam
Published: August 2010

In this study, effective computational procedures are introduced and used to characterize the dynamic behavior of cylindrical panels with circular cross-section having the single delamination between laminate layers. Based on the computed results it is possible to determine the effect of delamination on the overall structural dynamic behavior. Those results are used to quantify the difference between the results of the relevant parameters in the cases of perfect and defected structures. Usually, the wave propagation can be observed with the use of piezoelectric sensors. Therefore, in the next step of our analysis we modeled delaminated structures with a finite number of PZT sensors to consider also their influence on the structural dynamic response. The numerical analysis have been conducted with the use of 3D finite elements. A lot of numerical results allow us to understand better the influence of various parameters on the form of wave propagation in cylindrical multilayered shells.
Damage Detection of Sandwich Structure Using Time Domain Reflectometry
Authors: Kim Seung Il
Published: August 2010

Time Domain Reflectometry has been applied to detect damage on sandwich structure. Face plated need to be copper plated to embed sensor on surface. Core also needs to be conductive to send signal back. Total 6 lines of sensor were tested with varying impact energy and impact location. TDR were able to locate damage with high accuracy. Damage degrees were detectable for critical hit, but not clear enough to predict impact energy. However TDR was sensitive enough to detect damage that wasn’t visible by visual inspection.
Detection of Impact Location for Composite Stiffened Panel Using FBG Sensors
Authors: Park Sang Oh , Jang Byeong Wook , Lee Yeon Gwan , Kim Yoon Young , Kim Chun Gon , Park Chan Yik , Lee Bong Wan
Published: August 2010

We carried out experiments to detect impact locations on a composite plate using two types of composite plates, a composite flat plate with a constant thickness of 5 mm and a composite stiffened panel with stringers. Four multiplexed FBG sensors were attached to the bottom surface of the composite plates to acquire impact signals. The FBG sensor wavelength shift data were collected at a sampling frequency of 40 kHz using a high-speed FBG interrogator (SFI-710, Fiberpro Inc., Korea). The arrival times of the impact signals at each FBG sensor were obtained using a signal processing procedure. The arrival times were affected by noise level and signal-to-noise ratio. In order to overcome this weakness, signal processing techniques such as wavelet decomposition, normalization using each noise level and filtering with a moving average were adopted. To calculate the impact locations of the composite plate, a neural network algorithm was applied.