bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Characterization of Porous Si/Carbon Fibers
Authors: Jung Ki Ho , Park Soo Jin
Published: August 2010

In this work, poly(amide imide) (PAI) fibers containing various silicon content ratios were prepared for the precursor of carbon fibers by electrospinning method from 25 wt.% PAI in dimethylformamide (DMF) solution. The fibers were stabilized and then subsequently carbonized in a flow of nitrogen to obtain porous Si/carbon fibers. The morphologies and the crystalline structures of the Si/CFs were characterized by scanning electron microscopy (SEM) and X-ray diffractometer (XRD). The electrochemical behaviors of the Si/CFs were observed by cyclic voltammetry tests. The experimental results indicated that the Si/CFs exhibited convoluted structure and wrinkled surface morphology. The silicon particles had a uniform diameter of approximately 1 μm. And the electrochemical activity of the Si/CFs was gradually improved due to the buffering effect of the large Si volume expansion and shrinkage. In addition, the fibers exhibited large accessible surface area, high reversible capacity, and relatively good cycling performance at high current densities. Consequently, it was found that the introduction of silica could affect the electrochemical properties of the CFs, and the Si/CFs might have potential applications for various fields of electrochemical materials.
Synthesis and Electrochemical Performance of Porous Carbon/Carbon Electrode with Core/Shell Structure
Authors: Kim Ki Seok , Park Soo Jin
Published: August 2010

Recently core/shell nanostructures including nanotubes, nanowires, and nanofibers have a considerable attension because multiple or enhanced functionality can be obtained by the synergistic effect of different materials in the formation of a core/shell structure. In this work, porous carbon/carbon core/shell carbon electrode (P-C/C-CE) composed of core graphene and disordered shells were prepared to obtain a new type of carbon electrode materials. The disordered carbon shells were prepared by coating of polyaniline onto the graphene by in-situ polymerization in the presence of nano-sized silica and subsequent carbonization at 850°C. After carbonization, P-C/C-CE showed the hollow structure and crystallinity. In addition, P-C/C-CE exhibited superior electrochemical performance compared to graphene and graphene/PANI composites, which was attributed to the high surface area of P-C/C-CE and the presence of nitrogen groups formed onto carbon electrode after the carbonization of shell polyaniline.
Azo Dye-Yellow 17 Wastewater Photocatalytic Degradation of by UV/TiO2 Combined with Ultrasonic Procedure
Authors: Chang Chen Yu , Chang Yu Jie , Hsieh Yung Hsu , Lin Ching Hsing , Yen Shih Hung
Published: August 2010

. The study combined UV/TiO2 with ultrasonic procedure to degrade azo dye wastewater of Acid Yellow 17. The effects of factors including pH value, initial concentration of dye, and quantities of TiO2, Fe (II), and Fe (III) added on the removal efficiency of azo dye Acid Yellow 17 were investigated. Experimental results revealed significant additive effect attributed to the combination of two procedures under 13-watt UV irradiation and 10-watt ultrasound. Analysis of the catalyst properties indicated no evident changes in the appearance of crystal and TiO2 catalyst by UV/TiO2 combined with ultrasonic procedure. However, the specific surface area was increased by approximately 53%. No effective formation of hydrogen peroxide (ND  1 mg/L) proved that the addition of Fe (II) and Fe (III) failed to induce the Fenton-like reaction effectively. Nevertheless, the addition of Fe ions affected significantly the initial adsorption and the degradation rate of the dye. Moreover, the treatment efficiency of Fe (III) was found to be superior to that of Fe (II) under the same concentration.
Effect of Oxidizing Agents on Thermo-Mechanical Behavior of Jute Fabric-Reinforced Polypropylene Composites
Authors: Khan Jahangir A. , Khan Mubarak Ahmad , Rahman Nazia
Published: August 2010

Jute fabrics reinforced polypropylene (PP) composites were prepared by compression molding. Tensile strength (TS), tensile modulus (TM), bending strength (BS), bending modulus (BM) and impact strength (IS) of the composites were studied. To investigate the effect of oxidizing agents on the properties of the composites, jute fabrics were treated separately with the aqueous solutions of (0.005-0.05%w/v) potassium dichromate (K2Cr2O7) and (0.0025-0.04%w/v) potassium permanganate (KMnO4). The highest values of mechanical properties were reported for 0.02% K2Cr2O7 and 0.01% KMnO4 treatment. Thermal analysis of PP, treated and untreated jute fabrics and composites revealed that KMnO4 treatment lowers the thermal stability of the jute fabrics and composite. On the other hand, K2Cr2O7 treatment increases the stability of the fibers and composites. Hydrophilic nature of the treated composites was also reduced significantly.
Effects of Thermal Shock on Mechanical Properties of Bamboo/PBS Green Composites
Authors: Lee Yeon Hee , Takagi Hitoshi , Ohkita Kazuya , Yoon Han Ki
Published: August 2010

. This paper deals with the mechanical characterization of short bamboo fiber reinforced green composites (BFGC). The effects of thermal shock on the mechanical properties of BFGC were investigated. Their flexural strength was evaluated by 3-point bending test, and Vickers hardness and elastic modulus were evaluated by a nano-indentation method. The fracture surfaces and microstructure of BFGC were examined by SEM. The results of evaluated mechanical properties (3-point bending test) after thermal shock indicated that the strength of BFGC decreased below 40°C, however the strength became constant above 40°C. The Vickers hardness and modulus of elasticity evaluated from the nano-indentation tests also represented a similar trend to that of flexural strength. The fracture surface of thermal shocked BFGC after bending tests indicated the pull-outed bamboo fibers. This might be responsible for insufficient bonding between bamboo fiber and resin.
Mechanical and Biodegradation Behavior of Natural Fiber Composites
Authors: Takagi Hitoshi
Published: August 2010

This paper deals with the characterization of high strength and functional natural fiber reinforced composite materials which are fabricated using starch-based biodegradable resin and Manila hemp fiber. Hemp fiber reinforced cross-ply composites were prepared by a conventional hot-pressing method. Their mechanical characterization was carried out by evaluating tensile strength as a function of fiber content. It can be seen that the tensile strength of the cross-ply composites was saturated over 50 wt% due to the interaction between warp and weft during the hot-pressing. However in the case of flexible weft; such as cotton thread or resin fiber, the tensile strength of the cross-ply composites almost linearly increased with increasing fiber content. The biodegradation behavior of the hemp fiber reinforced unidirectional composites was also examined by burying them into compost media. The changes in surface morphology of the specimen and in specimen weight loss were monitored for 30 days. It is apparent that the natural fiber reinforced composites showed an enhanced biodegradation speed. This enhanced biodegradation behavior seems to be derived from increased apparent surface area of the composite specimen due to the preferential biodegradation at interface between hemp fiber and biodegradable resin as well as the preferential water transportation through internal cavity in hemp fiber.
Mechanical Properties, Morphological Properties, and Cure Characteristics of Sisal Fiber/Natural Rubber Composites: Effects of Fiber and Compatibilizer Content
Authors: Wongsorat Wittawat , Suppakarn Nitinat , Jarukumjorn Kasama
Published: August 2010

Sisal fiber/natural rubber (NR) composites were prepared by the incorporation of sisal fiber into NR at various content (10, 20, 30 phr) using a two-roll mill. Natural rubber grafted with maleic anhydride (NR-g-MA) prepared in house was used to improve interfacial adhesion between sisal fiber and NR matrix. NR-g-MA contents were varied. Mechanical properties, morphologies, and cure characteristics of the composites were studied. Maximum torque, modulus at 100% strain (M100), modulus at 300% strain (M300), and hardness of the composites increased with increasing fiber content while scorch time, cure time, tensile strength, and elongation at break decreased. The addition of NR-g-MA into the composites gave a positive impact on M100, M300, tensile strength, and hardness. Moreover, increasing NR-g-MA content resulted in increased scorch time, cure time, maximum torque, M100, M300, tensile strength, and hardness of the composites. SEM micrographs of the composites revealed that the addition of NR-g-MA into the composites improved the interfacial interaction between sisal fiber and NR matrix. In addition, the compatibilized NR composites exhibited higher specific tensile strength and modulus than the carbon black/NR composites.
Natural Fiber Reinforced Polystyrene Matrix Based Composites
Authors: Singha Amar Singh , Rana Raj K. , Rana Ashvinder
Published: August 2010

The present study deals with the preparation of natural fiber reinforced polystyrene composites by compression molding technique in which good interfacial adhesion is generated by fiber surface modification. The fiber surface was modified through graft copolymerization of methyl methacrylate onto the fiber surface. The short grafted fibers were then spread between the alternate layers of polystyrene resin by hand lay up method to obtain the composites. The samples of the composites thus prepared were characterized by FTIR spectroscopy, scanning electron microscopy and thermogravimetric analysis. The composites were then evaluated for mechanical properties like tensile strength, compressive strength, flexural strength and wear resistance etc.
Study of Characteristic of Vetiver Fiber Before and after Alkaline Treatment
Authors: Sutapun Wimonlak , Suppakarn Nitinat , Ruksakulpiwat Yupaporn
Published: August 2010

In this study, untreated and alkali-treated vetiver fibers were characterized by thermogravimetric analysis, BET surface analysis, X-ray diffraction and FTIR (ATR) microspectroscopy,. It was revealed that the alkaline treatment influenced properties of vetiver fiber. By the treatment, some hemicellulose and lignin were removed, resulting in higher decomposition temperatures. In addition, the specific surface area were decreased, and crystalline structure was altered. However, no evidence of changes in surface functional groups was observed.
Influence of Base Thickness on Performance of 1-3-2 Piezoelectric Composite
Authors: Cheng Xin , Liao Shuang Shuang , Huang Shi Feng , Guo Li Li
Published: August 2010

Sulphoaluminate cement and Lead Niobium-Magnesium Zirconate Titanate ceramic [P(MN)]ZT were used as matrix and functional phase respectively to fabricate 1-3-2 cement-based piezoelectric composites by dice and filling technique. The influences of base thickness on piezoelectric properties, electromechanical properties and acoustic impedance properties of the composites were discussed. The results show that as the base thickness increases, the piezoelectric stain factor d33 increases gradually, while the piezoelectric voltage factor g33 decreases. The planar electromechanical coupling coefficient Kp exhibits the trend of decrease, while the thickness electromechanical coupling coefficient Kt and acoustic impedance show the increasing trend. The mechanical quality factor Qm reaches the minimum (1.49) when base thickness is 2.00 mm. The results reveal that the 1-3-2 piezoelectric composite will be suitable for application by changing the base thickness.
Effect of Si on the Mechanical Properties of WC-Ni Hard Metal
Authors: Jang Ki Hwan , Seo Seung Pil , Kim Chan Yeong , Kim Ki Yeol , Lee Gil Geun
Published: August 2010

The purpose of this study is to prescribe the influence of Si in WC-Ni Hard Metal. For the manufacture of WC-Ni Hard Metal according to Si content, the researcher manufactured WC-Ni mixed powder which 0wt.%~1.5wt.% of Si was added to after selecting Ni which a fixed amount of B was added to, and then manufactured sintered body by implementing vacuum-sintering to the mixed powder. This study implemented the analysis with HRA, TRS, XRD, SEM, and EPMA to observe densification, alloying reaction, and mechanical properties of the sintered body.
In WC-Ni Hard Metal, shrinkage showed a tendency to increase as Si content increased. It is considered that the densification was promoted during liquid phase sintering, because a melting point of binder metal got lower as Si content increased.
The hardness of WC-Ni Hard Metal was kept uniformly up to 0.6wt.%Si, and then it showed the tendency to increase from the level of 0.9wt.%Si. It is considered that the hardness of B and Si added to Ni binder metal formed BNi3 phase and Ni3Si phase which had high hardness, and these compound phases restrained the growth of WC particle.
It is considered that transverse rupture strength of WC-Ni Hard Metal according to the increase of Si content was increased by the decrease of mean free path of WC particle caused by the improvement of fluidity according to the restrained growth of WC particle by of BNi3 phase and Ni3Si phase, and caused by the improved fluidity according to the decreased melting point of Ni binder metal.
Effect of Silica Size on the Thermal, Mechanical and Biodegradable Properties of Polylactide/Silica Composite Material Prepared by Melt Blending
Authors: Huang Tsao Cheng , Yeh Jui Ming , Yang Jen Chang
Published: August 2010

In this study, we attempt to investigate the effect of silica size on the thermal, mechanical and biodegradable properties of polylactide/amino-silica (PLA/SiO2) composite material, by preparing the PLA/ SiO2 hybrids containing different size of silica particle through twin-screw extruder. First of all, we prepared amino-functionalized silica particles through performing the conventional base-catalyzed sol-gel reaction of methyltrimethoxysilane (MTMS) and 3-aminopropyltrimethoxysilane (APTMS). The average diameter of silica particle employed in hybrids was 150 nm (S-silica) and 1μm (B-silica), respectively. Systematically comparative studies on the thermal properties and mechanical strength of hybrids containing two different sizes of SiO2 particles materials were carried out on a basis of studies of thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). It should be noted that the mechanical strength of hybrids containing smaller size of silica particles was found to reveal significant improvement in storage modulus as compared to its corresponding counterpart based on the DMA investigation. Moreover, the thermal stability of hybrids containing smaller size of silica particles was found to reveal slight improvement in glass transition temperature as compared to its corresponding counterpart based on the DSC investigation. Eventually, the as-prepared hybrids were found to exhibit almost similar degradation behavior to that of neat PLA.
Moisture Management Performance of Multifunctional Yarns Based on Wool Fibers
Authors: Sousa Fangueiro Raul Manuel Esteves , da Cunha Soutinho Hélder Filipe , Freitas Carla
Published: August 2010

Blends of wool and moisture management fibres such as Coolmax and Finecool have been prepared to produce innovative yarns with specific functionalities. These yarns have been used to produce knitted fabrics and their performance was evaluated, including vertical and horizontal wicking. The influence of wool fibre proportion on the performance of each blend is analyzed. It is observed that the Coolmax based fabrics show the best capillarity performance, and the wool fibre based fabrics show lower water absorption performance.
Preparation, Characterization and Thermal Properties of Green Polypropylene/Intumenscent Flame Retardant Composites
Authors: Kuan Chen Feng , Hsu Shu Wei , Chen Wei Jen , Li Yi Luen , Chen Chia Hsun , Kuan Hsu Chiang , Chiang Chin Lung
Published: August 2010

Polypropylene (PP) has the disadvantage of flammability and easy dripping, flame retardant was incorporated into polymer to improve the thermal and flame retardant property. Conventional flame retardant containing halogen would release toxic gases when the materials got fire and let the people died in the fire and destroy the environment. Intumenscent flame retardant consists of three key components: acid source, carbon source and blowing agent. Acid source is phosphoric acid, which can dehydrate the materials. Carbon source can form char layer to prevent further thermal degradation. The blowing agent can swell the carbon layer to avoid heat and mass transfer during material get fire. Novel intumenscent flame retardant which contains phosphorus and nitrogen was successfully prepared. FTIR, TGA, LOI and UL-94 were used to characterize the structure, flame retardant mechanism and thermal property of the composites. LOI and UL-94 data showed the composites possess excellent flame retardant property. For kinetic of thermal degradation.
Surface Preparation Based on the Corrosion Behavior of on the Austenite Stainless Steel 304
Authors: Moon Min Seok , Woo Kee Do , Yoo Myeong Han , Kwak Chan Won , Han Jin Won
Published: August 2010

Nowadays, many economist and scientist worried for sharply increased to fuel consumption. Developed and developing countries investigation new energy system. It is base on the low emission gas, high energy efficiency, permanence and cogeneration. Specially, transportation system has restricted to system’s total weight. It is concern with light weight offer to increase to performance by itself. And give to other benefit that reduce to oil consumption, improved fuel economy, engine downsizing and increased to Market-value. Fuel cell is one of the new energy systems for next generation. Normally, fuel cell is consisting of bipolar plate, MEA (Membrane Electrode Assembly) and GDL (Gas Diffusion Layer). Conventional bipolar plate material was applied Graphite. Graphite has very weak for external shock, machining process is not easy, and the main problem is that the graphite material supplied by oxidizing and reducing agent composition of the gas leak comes. Thus, by this reason, the manufacturing cost is increased.
In this study, to replace the graphite material was selected as a metal material. In this experiment, STS304 austenite base stainless steel is used. This study was based on the metal material’s corrosion behavior observed with 2 type’s surface pretreatment on the STS304 with similar PEMFC operating condition. Experimental results, As-Polished condition has good corrosion resistance better than As-Received condition. It was concerned with passivation layer.
Thermally Stable Polyimide/Silica Hybrid: Synthesis, Characterization and Optical Nonlinearity
Authors: Wu Guang Yu , Yao Cheng , Qiu Feng Xian
Published: August 2010

An intercalation nonlinear-optical (NLO) polyimide was synthesized based on the 3,3’, 4,4’- Bisphenyltetracarboxylic (BPDA) and [(6-nitrobenzothiazole-2-yl)diazenyl]phenyl-1,3- diamine (NBADA). Then, hybrid polymer was synthesized by the sol-gel technique. FT-IR spectroscopy and 29Si NMR were used to characterize the structure of the hybrid. The results revealed that Q3, Q4 and T3 are the major microstructure elements in forming a network structure. The surface morphology, particle size, crystallinity and the thermal stability of the hybrid were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). DSC and TGA results showed that the glass transition temperature (Tg) and the decomposition temperature (Td) at 5% mass loss were 243, 359°C and 355, 456°C, respectively. These results showed that the hybrid material had excellent thermal stability than the pure polyimide. The electro-optic coefficients of nonlinear optical polyimide and hybrid were measured at the wavelength of 832 nm. The electro-optic coefficients were 22 and 19pm/V (poling voltage of 3.8KV, 210°C) and the values remained well (retained＞93% for more than 100h). The results suggest that the materials have potential applications for high performance optical device.
Study on Modified Rapeseed Oil/Montmorillonite Nanocomposites
Authors: Lü Bin , Ma Jian Zhong , Gao Dang Ge , Hong Lei
Published: August 2010

Modified rapeseed oil(MRO) was prepared by using rapeseed oil, ethylene diamine and acrylic acid as the raw materials. Modified rapeseed oil/montmorillonite(MRO/MMT) nanocomposite was prepared by using modified rapeseed oil and montmorillonite. The emulsifying properties of MRO and MRO/MMT were determined respectively. Fourier transforms infrared spectrometry (FT-IR) and Transmission Electron microscope (TEM) results showed that MRO/MMT was prepared successfully. X-ray diffraction (XRD) results showed that modified rapeseed oil could smoothly enter the interlayer of montmorillonite, and modified the montmorillonite; with an increase in the amount of montmorillonite, the layer spacing of montmorillonite in the MRO/MMT lower after the first increase. The results of emulsifying properties indicated that emulsifying properties of MRO/MMT was better than MRO.
Preparation of Flower-Like Silica Microstructures
Authors: Wang Wen Qi , Peng Zhen Sheng
Published: August 2010

Novel flower-like silica microstructures have been synthesized through heating silicon, silicon monoxide and active carbon mixed powders under an H2/Ar (3%) atmosphere at 1050°C without assistance of any metal catalyst. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and energy dispersive x-ray spectrometer (EDS) analyses reveal that the wires are amorphous and consist only of silicon oxide, generated from the reaction of CO with SiC. A possible growth model based on both of vapor-solid (VS) and the Oxide-assisted growth (OAG) mechanism has been supposed here to explain this phenomenon.
Preparation and Characterization of Functionalized Graphene/Linear Low Density Polyethylene Nanocomposites
Authors: Kuila Tapas , Uddin Md Elias , Kim Nam Hoon , Yoo Gye Hyoung , Lee Joong Hee
Published: August 2010

The present work deals with the functionalization of graphene sheet and preparation of functionalized graphene/linier low density polyethylene (LLDPE) nanocomposites by solution-mix techniques. Dodecyl amine (DA) has been used for the surface modification of graphene oxide (GO) and hydrazine as reducing agent. Fourier transform infrared (FTIR) spectra exhibits the appearance of new peaks in the functionalized graphene (DA-G), which suggests the functionalization of graphene by DA. X-ray diffraction (XRD) analysis infers the formation of fully exfoliated DA-G/LLDPE nanocomposites. The tensile strength (TS) and elongation at break (EB) of the composites are higher in comparison to neat LLDPE. The nanocomposites with only 0.5 wt.% of DA-G content results in TS and EB to be 17% and 10% higher compared to neat LLDPE. TGA shows that the thermal stability of the DA-G/LLDPE nanocomposites is higher compared to pure matrix polymer.
Preparation of Organic-Inorganic Core-Shell Particles and Influence on Corrosion Resistance of Cement
Authors: Wang Qi , Liu Zhen , Song Peng , Tian Lu Fei
Published: August 2010

Porous materials were prepared by sintering using C as place holder and SiO2 as based, mixed with paraffin. Then Organic-inorganic Core-shell Particles were made by crushed. With the help of XRD and SEM, on the 60°C Study on Sulfate-Corrosion Resistance of cement Mixed with Organic-inorganic Core-shell of Preparation. The Organic-inorganic Core-shell Particles made by accounted of C 15% and heat preservation 4h in 920°C were the best. The results showed that when the content of Organic-inorganic Core-shell Particles was 15%, the Sulfate-Corrosion Resistance reached the climax.
Rapid Consolidation of Nanocrystalline Al2O3 Reinforced Cr Composite from Mechanically Alloyed Powders by Pulsed Current Activated Sintering
Authors: Shon In Jin , Kang Hyun Su , Lee Dong Mok , Na Kwon Il , Ko In Yong
Published: August 2010

Nanopowders of Cr and Al2O3 was fabricated from CrO3 and 2Al by high energy ball milling. Dense nanocrystalline Cr-Al2O3 composite was consolidated by pulsed current activated sintering (PCAS) method within 1 min from mechanically alloyed powders. Highly dense Cr-Al2O3 with relative density of up to 99% was produced under simultaneous application of a 80 MPa pressure and the pulsed current. The average grain size and mechanical properties of the composite were investigated.
Relative Post-Buckling Stiffness Calculation of Symmetrically Laminated Composite Plates Using an Exact Finite Strip
Authors: Ghannadpour Seyyed Amir Mahdi , Ovesy Hamid Reza
Published: August 2010

This paper presents the theoretical developments of an exact finite strip for the buckling and initial post-buckling analyses of symmetrically laminated composite plates. The so-called exact finite strip is developed based on the concept that it is effectively a plate. The present method, which is designated by the name Full-analytical Finite Strip Method in this paper, provides an efficient and extremely accurate buckling solution. In the development process, the Von-Karman’s equilibrium equation is solved exactly to obtain the buckling loads and the corresponding form of out-of-plane buckling deflection modes. The investigation of thin flat plate buckling behavior is then extended to an initial post-buckling study with the assumption that the deflected form immediately after the buckling is the same as that obtained for the buckling. The post-buckling study is effectively a single-term analysis, which is attempted by utilizing the so-called semi-energy method. In this method, the Von-Karman’s compatibility equation governing the behavior of symmetrically laminated composite plates is used together with a consideration of the total strain energy of the plate. Through the solution of the compatibility equation, the in-plane displacement functions are developed in terms of the unknown coefficient in the assumed out-of-plane deflection function. These in-plane and out-of-plane deflected functions are then substituted in the total strain energy expressions and the theorem of minimum total potential energy is applied to solve for the unknown coefficient. The developed method is subsequently applied to analyze the initial post-buckling behavior of some representative thin flat plates for which the results are also obtained through the application of a semi-analytical finite strip method. Through the comparison of the results and the appropriate discussion, the knowledge of the level of capability of the developed method is significantly promoted.
Solid Particle Erosion of Particulate Filled Short Glass Fiber Reinforced Polyester Resin Composites
Authors: Patnaik Amar , Kaundal Ritesh , Satapathy Alok , Biswas Sandhyarani , Kumar Pradeep
Published: August 2010

Fiber reinforced composite materials have been used in main parts of structures; an accurate evaluation of their erosion behavior becomes very important. In this study, short glass fibre reinforced polyester based isotropic polymer composites are fabricated with five different fibre weight-fractions. The effect of various operational variables, material parameters and their interactive influences on erosive wear behavior of these composites has been studied systematically. After systematic analysis of solid particle erosion for all the five composites, 30wt% short glass fiber reinforced polyester based composite shows better erosion resistance. In order to improve the erosion resistance further ceramic silicon carbide particle is reinforced with the 30wt% glass-polyester based hybrid composites. A ﬁnite element (FE) model (LS-DYNA) of erosive wear is established for damage assessment and validated by a well designed set of experiments. For this, the design of experiments approach using Taguchi’s orthogonal arrays design is used. It is recognized that there is a good agreement between the computational and experimental results, and that the proposed simulation method is very useful for the evaluation of damage mechanisms.
Studies on Preparation and Properties of LiFePO4 Cathode Material Modified by Polyacenic Semiconductor Materials for Lithium Ion Batteries
Authors: Wang Cun Guo , Ding Zhao Long , Lu Nai Qun
Published: August 2010

The composite materials of LiFePO4 powder coated with polyacenic semiconductor materials (PAS) were successful prepared. Effects of the preparation conditions, such as precursor material, annealing temperature et al., on the structure and electrochemical properties of LiFePO4 were studied. SEM images and TG thermogravimetric analysis of the obtained carbon coating microspheres suggest that LiFePO4 powder was successfully encased within the carbon gel microspheres. The electrical conductivity of the composite materials could get to 10-2 S•cm-1. It was found that the composite LiFePO4 material exhibits excellent capability with initial discharge capacity more than 210 mAhg–1. The discharge capacity goes up to 340 mAh/g after ten times of cycle.
Study on the Mechanical and Electrical Properties and Creep Behaviour of Carbon Fiber Nano-Composites
Authors: Li Yi Luen , Chen Wei Jen , Chiang Chin Lung , Yip Ming Chuen
Published: August 2010

In recent years, the influence of surface modification of carbon nanotubes (CNTs ) on CNT’s dispersion among epoxy resin, mechanical properties and electrical conductivities of CNTs has been observed.
On account of above-mentioned effects, that CNTs treated with oxidizing in organic acids, a kind of surface modification, generates functional groups on the surface of CNTs is a major investigation in this study to enhance mechanical properties and electrical conductivities of CNTs.
In this study, CNTs dispersed among epoxy resin well by adopting ultrasonication method and then the nano-prepreg was fabricated by mixing CNTs/Epoxy resin into carbon fiber. The influence of the different proportion contents of CNTs added into Epoxy resin on mechanical properties and electrical conductivities of composites is investigated. The strength of material tested under different circumstance is also observed. Furthermore, the creep behavior of carbon fiber/epoxy resin thermosetting composites tested under different circumstance and stress is also concerned to be analyzed.
Synthesis of Carbon-Encapsulated Metal (Fe,Co,Ni) Nanoparticles by Detonation Decomposition of Composite Explosives
Authors: Li Xiao Jie , Luo Ning , Yan Hong Hao , Wang Xiao Hong
Published: August 2010

A detonation method for synthesizing carbon-encapsulated metal nanoparticles (CEMNPs) is reported. The composite precursors containing various nitrate dissolved in absolute ethanol is ignited by a nonelectric detonator in nitrogen gas in an explosion vessel. The material characteristics of these nanoparticles are then examined with the XRD,TEM,EDX and RS. The results show that the composite particles whose coating shell were graphite carbon could be dispersed finely. The core of nanoparticles were composed of iron, cobalt and nickel crystal to that of the above explosive precursors.
The Inhibition Effect of TiO2/Ag Thin Film on Acinetobacter baumannii
Authors: Hsieh Ling Ling , Chang Chen Yu , Shyu Huey Lih , Tsou Chi An , Lo Hsueh Hsia
Published: August 2010

The nosocomial infections caused by opportunistic pathogen Acinetobacter baumannii was increasing in recent years. It was known that the attachment of A. baumannii on solid surface was a key factor for infection. This study was conducted to evaluate the inhibitory effect of titanium dioxide (TiO2)/Ag thin film on A. baumannii. In this study, TiO2 thin films were firstly prepared by using the modified impregnation method, then TiO2/Ag thin films were prepared by using the spin-coating with 5000 ppm Ag+. The TiO2/Ag thin film was analyzed by field-emission scanning electron micrographs and X-ray diffractometer. The nano-size and Anatase crystal structure were confirmed. Twenty clinical A. baumannii isolates were examined for the bactericidal effect of TiO2/Ag thin film either in the dark or under visible light activation for 20 min. The inhibition efficiencies of TiO2/Ag thin film under visible light on these 20 isolates ranged from 41% to 90%. The effects of TiO2/Ag thin film in the dark were slightly lower than visible light-activated group. Our results suggested that coating of TiO2/Ag on solid surface in hospital environment might be helpful for the prevention of nosocomial A. baumannii infection.
The Study on the Decomposition of Azo Dye by La-Modified TiO2
Authors: Yao Kuo Shan , Hsieh Yung Hsu , Chang Yu Jie , Lin Ching Hsing , Chang Chen Yu , Chiang Ya Chi
Published: August 2010

The La/TiO2 photocatalyst was prepared by lanthanum into TiO2 structure in a sol-gel process. The catalyst was characterized by field-emission scanning electron microscope (FE-SEM), X-ray diffractometer (XRD), ESCA, and Brunauer Emmett Teller (BET) analyses. Photocatalytic activities of the supported catalysts were examined through decomposition process of azo-dye Acid Yellow 17 solution under UV irradiation. The results showed that the particle size of TiO2 is about 20 nm, and the particle of La/TiO2 is about 10 nm. The crystal structure is mainly in anatase phase, the contents of the rutile phase increase with the increase of the amount of doped lanthanum. The adsorption capacity of La/TiO2 catalysts increases with lanthanum dosage in the acidic solution. The contribution of actual photodecomposition was determined by desorption process, after the photocatalytic reaction. In the acidic solution, better photodecomposition efficiency is achieved than in the neutral or alkaline solution. The experiments demonstrated that the optimum doping of La at 10 mol %, the maximum photodecomposition in dye concertration at 15 mg L-1 and photocatalytic dosage at 0.75 g L-1, achieving the highest effect.
Thermal Post-Buckling Analysis of Functionally Graded Composite Plates with Nonlinear Aerodynamic Forces
Authors: Lee Chang Yull , Kim Ji Hwan
Published: August 2010

The post-buckling of the functionally graded composite plate under thermal environment with aerodynamic loading is studied. The structural model has three layers with ceramic, FGM and metal, respectively. The outer layers of the sandwich plate are different homogeneous and isotropic material properties for ceramic and metal. Whereas the core is FGM layer, material properties vary continuously from one interface to the other in the thickness direction according to a simple power law distribution in terms of the volume fractions. Governing equations are derived by using the principle of virtual work and numerical solutions are solved through a finite element method. The first-order shear deformation theory and von-Karman strain-displacement relations are based to derive governing equations of the plate. Aerodynamic effects are dealt by adopting nonlinear third-order piston theory for structural and aerodynamic nonlinearity. The Newton-Raphson iterative method applied for solving the nonlinear equations of the thermal post-buckling analysis
Absorbable Suture Made from Rice Starch
Authors: Punyanitya Sittiporn , Koonawoot Rungsarit , Thiensem Sakdiphon , Laosatirawong Surasit , Raksujarit Anirut
Published: August 2010

The main objective of this work is to make an absorbable monofilament suture from Thai rice starch. The improvement of the mechanical properties of Thai rice starch polymer films were achieved by addition of small amount of gelatin, carboxymethylcellulose (CMC) and carbon nanopowders. The carbon nanopowders were produced from coconut shell in our laboratory room by milling method. The incorporation of carbon nanopowders with a high aspect ratio and/or an extremely large surface area into Thai rice starch polymer films improves their mechanical performances significantly. Additionally, the black color from carbon nanopowder is easily visualized in tissue during surgery. The manufacturing processes are very simple by blending of the raw materials in hot water and then dry heating in electric oven. The final product was characterized of microstructures and mechanical properties. The resulting Thai rice starch-carbon nanocomposites possess several advantages for manufacture of sutures: 1. high water resistance that can be uses in the human body. 2. high mechanical strength that appropriate to manufacture of sutures. 3. biocompatibility and bioabsorbable. 4. low cost. 5. Eco-friendly green nanocomposites. However, the method of size designation of sutures fibers and needle attachment are the problem which restricts our suture in really applications. The investigation of knowledge and simple technology of manufacture of suture and needle attachment will be performed.
Carboxymethyl Chitosan/Hydroxyapatite Composite Scaffold for Bone Regeneration
Authors: Bao Xu Xu , Li Yuan , Teramoto Akira , Abe Koji
Published: August 2010

Natural bone is a composite mainly made from nano/micro-structure of hydroxyapatite and collagen fibers. For bone regeneration by tissue engineering, it is important to synthesize nano-composites with good biocompatibility, high bioactivity and great bonding property as potentially useful scaffold. In this study, we fabricated chitosan nano-nonwoven scaffold via electrospinning and modified chitosan scaffolds by carboxymethylation (CM). Moreover scaffolds were macerated in SBF (simulated body fluid) to form hydroxyapatite on its surface. Surface morphologies (SEM) showed that nano/micro particles formed on the surface of the carboxymethyl chitosan fibrous scaffold. Results of FT-IR and XRD confirmed that the nano/micro particles were hydroxyapatite crystalline. Moreover by employed mice osteoblast (MC3T3-E1) cell for adhesion, proliferation and differentiation assays, and the hydroxyapatite particles appeared to have a great effect on the late stages of osteoblast behavior (alkaline phosphatase ).
Characterization of Microstructure and Compressive Deformation Behavior of Reinforced Porous Poly(L-lactide)
Authors: Park Joo Eon , Todo Mitsugu
Published: August 2010

Novel reinforcements such as beam, film, and porous frame were developed to improve the mechanical properties of poly(L-lactide) (PLLA) scaffolds. A solid-liquid phase separation method was used to fabricate porous structures such as core portions and porous frame of reinforced scaffolds. The beam and film reinforcements were also fabricated from PLLA pellets by applying the thermal-press technique. In the standard scaffold, the localized deformation was characterized as buckling of the pore structures. On the contrary, the primary microstructural deformation mechanism in the beam and the film reinforced scaffolds was characterized as buckling deformation and interfacial failure of the matrix and the reinforcement respectively. It is also seen that the inner porous structure could maintain the initial structure without local buckling of the pore structure. The compressive mechanical properties of the reinforced scaffolds were dramatically improved by about 2 ~ 5 times compared to the standard scaffold.
Dynamics of Flower Head Movement in Bio-System
Authors: Shiono Masahiro , Kitadera Kohei , Sudo Seiichi
Published: August 2010

This paper is concerned with plant biomechanics to obtain inspiration for innovative engineering technology from nature. The dynamics of the flower head movement and the plant growth was studied experimentally. The folding and unfolding movements of the petals of cut dandelion flower heads were observed by the low-speed photographing method. Movements of cut dandelion flower heads were observed as movies, and analyzed by the personal computer. The surface cell form of the petal of the dandelion, Taraxacum officinale, was also observed by the laser beam microscope. The time change of the surface form of petal cells was clarified.
Fabrication of Gelatin/Carbon Nanocomposite for Human Tissue Adhesive
Authors: Koonawoot Rungsarit , Punyanitya Sittiporn , Tirapong Chatchai , Boonchom Kritsada , Raksujarit Anirut
Published: August 2010

Successful human tissue adhesives depend on sure parameters which cannot be matched by any one adhesive. In this work, the novel human tissue adhesive is fabricated from gelatin and coconut shell carbon nanopowder composite. Characteristics of the carbon powder and the product samples were then investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM). Mechanical characterization and tissue adhesive bonding test of the final product were also performed.
Photocuring of Gelatin Films with TMPTMA: Effect on Aging Properties
Authors: Rahman Nazia , Khan Mubarak Ahmad , Khan Ruhul Amin , Mollah M.Z.I. , Chowdhury Tofail A.
Published: August 2010

Gelatin films were prepared from granular gelatin by casting. Gelatin films were modified by photocuring with a trifunftional monomer Trimethylolpropane trimethacrylate (TMPTMA). Optimum condition for photocuring were established. Water aging of untreated and modified gelatin films was studied. Thermal aging of untreated and TMPTMA treated films were determined at different temperatures (50°C, 70°C and 100°C) for 60 min. pH aging of gelatin films were investigated in different pH solutions (3.2, 4.1, 4.8, 6.9, 9.2, 12.2) for 1min. Water aging, thermal aging and pH aging showed that the TMPTMA grafted gelatin films experienced less deterioration of mechanical properties than pure gelatin films.
Preparation of Degradable Tencel Composite Dressings
Authors: Lin Jia Horng , Lu Chao Tsang , Wu Zong Han , Lin Chin Kai , Lin Ching Wen , Lou Ching Wen
Published: August 2010

Tencel® is famous for its green manufacturing process and biodegradable ability. In this study, Tencel® was used as dressing matrix materials owing to its good water absorption and smooth fiber surface. Tencel® nonwoven fabric is prepared by needle punching. Then pectin/Chitosan composite solution was coated onto the Tencel® nonwoven fabric to fabricate pectin/Chitosan/Tencel® composite dressing. The best parameters were prepared by compounding the 3 wt% pectin and 1 wt% Chitosan in volume ratio of 60/40 for good moisture retention, proper swelling rate and slower degradable speed. Coating the pectin/Chitosan solution onto the Tencel® fabric brought low the pectin/Chitosan/Tencel® composite dressing’s permeability by 40%. Nevertheless, tensile strength and tearing strength of that pectin/Chitosan/Tencel® composite fabric were improved by 11% and 2%, respectively.
Removal of Cationic Dye from Aqueous Solution by Adsorption on Activated Carbon Developed from Xanthoceras Sorbifolia Bunge Hull
Authors: Hao Yi Nan , Wang Xi Ming , Pang Fang Liang
Published: August 2010

Adsorption of cationic dye, methylene blue (MB) onto Xanthoceras Sorbifolia Bunge hull activated carbon (XSBHAC) developed by zinc chloride solution activation has been investigated. Exp eriments were carried out as function of contact time, pH (2-10) and temperature (293, 303, 313 and 323K). Adsorption isotherms were modeled with the Langmuir and Freundlich isotherms. The data fitte d well with the Langmuir isotherm. The Langmuir monolayer saturation capacities of MB adsorbed onto activated carbon were 501.32, 534.54, 588.30 and 593.28mg/g at 293, 303,313, and 323 K, respect ively. The kinetic models were also studied. The rates of adsorption were found to conform to the pseu do-second-order kinetics with good correlation. Using the equilibrium concentration contents obtained at different temperatures, various thermodynamic parameters, such as△G, △H and△S, have been calc ulated.The thermodynamics parameters of system indicated spontaneous and endothermic process.
Synthesis and Characterization of SA-g-MAA Co-Polymer: Effect of Grafting and Process Variables on Controlled Release of an Anti-Bacterial Drug
Authors: Prasad C.V. , Sudhan Rao K.M. , Mallikarjuna B. , Subha M.C.S. , Rao K. Chowdoji
Published: August 2010

Methacrylic acid (MAA) was grafted onto sodium alginate (SA) by thermal heating at ambient temperature (70±2OC) using potassium persulphate as an initiator (PPS). SA-g-MAA and pure sodium alginate beads were prepared and were characterized using Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray diffraction techniques (X-Rd). The resultant products (SA-g-MAA) were used to prepare Glutaraldehyde (GA) crosslinked beads of various formulations by varying, monomer, cross-linker (GA) and drug content (CFHCl) in the graft co-polymer. Preparation conditions of the beads were optimized by considering the percentage entrapment efficiency, swelling capacity and release profiles. Release profile of CFHCl was discussed at 370C in a gastrointestinal atmosphere (pH -7.4 and acidic medium pH-1.2). It was observed that, CFHCl release from the beads increased with increasing MAA content over the entire studied range. As GA and CFHCl content increases, swelling ratio decreases resulting in decrease in the drug release rate. The highest CFHCl release was obtained to be 99% for the beads containing 40% monomer, 0.5mL GA and 10% CFHCl at pH-7.4. It was also observed that the release profiles have effect on pH and hence the graft co-polymeric beads can be used as pH sensitive drug devices.
Constructability and Performance of Prospective Materials for Repair of Airfield Damaged Concrete
Authors: Lee Ming Ju , Lee Ming Gin , Huang Yi Shuo , Tia Mang
Published: August 2010

The surfaces of concrete airfield aprons and runways deteriorate for a number of reasons, such as surface scaling due to freeze/thaw, impact loading, hot weather, de-icing fluids, deterioration of joints, jet fuel chemicals and so on. A limited field and laboratory study was performed to investigate the constructability and performance of prospective materials for repair of airfield concrete damaged by exposure to heat and oil. Two prospective coating materials and six prospective inlay materials were field-testes at the Base in USA Kansas, and were evaluated in the laboratory at the University of Florida before and after the field installation. The results of the study indicate that it is feasible to repair these damaged concrete surfaces by placing a suitable inlay material with a minimum depth of 2 inches. Among the prospective inlay materials investigated, two promising materials for this application are a magnesium phosphate concrete (Set-45) and a calcium aluminate concrete (Fondag). Both two concretes set very quickly, and make high early-strength, impermeable patches that bond to clean and dry surfaces. Guidelines for the placement of inlay materials for this purpose are proposed based on the experience from this study.
Effect of UV and Gamma Radiation on the Mechanical and Degradation Properties of LLDPE-Clay Composites
Authors: Khan Mubarak Ahmad , Islam Rafiqul , Islam Towhidul , Nigar Farah , Rahman Nazia , Rahman M. Mizanur , Mustafa A.I.
Published: August 2010

Composites containing various amounts of LLDPE (Linear Low Density Polyethylene) and clay (0, 1, 5, 10, 20 and 30% of clay) were prepared using two different types of clay (Bijoypur white clay and China clay) by extrusion technique followed by compression molding. Tensile strength (TS) & tensile modulus (TM) of pure LLDPE were found to be 9.8 MPa & 175 MPa respectively. For both types of clay TS, Eb% was gradually decreased but TM was gradually increased with increasing the percentage of clay in LLDPE/clay composites. The effects of ionizing (gamma) and non-ionizing (UV) radiations on the mechanical properties of LLDPE/clay composites were studied. The composites irradiated under UV & gamma radiation showed higher TS than that of non-irradiated one. Thermal degradation of the composites was studied at different temperatures. Water uptake of the composites was found negligible.
Effective Cutoff Wavelength Measurement of Bend-Insensitive Fiber by Longitudinal Misalignment Loss Method
Authors: Htein Lin , Fan Wei Wei , Watekar Pramod R. , Han Won Taek
Published: August 2010

We introduced a simple experimental set-up and determined the effective cutoff wavelength of bend-insensitive optical fibers by applying the longitudinal misalignment loss with spectral transmission method.