bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Characterization of Bacterial Cellulose Nanocrystals and their PVA Nanocomposites
Authors: George Johnsy , Bawa Amarinder S. , Siddaramaiah
Published: August 2010

Cellulose, the most widespread biopolymer, is known to occur in a wide variety of living species from the worlds of plants and microbial sources like bacteria. Bacterial cellulose produced by Gluconacetobacter xylinus in the form of long fibers can be acid hydrolyzed under controlled conditions to obtain nanocrystals. Such nanocrystals constitute a generic class of ‘green’ nanomaterial and have attained great importance in the field of polymer nanocomposites attributed to their superior properties. However, conventional sulfuric acid hydrolysis route provides cellulose nanocrystals with inferior mechanical and thermal properties. In this study, a hydrochloric acid (HCl) assisted top down approach has been adopted to synthesize bacterial cellulose nanocrystals, which is found to retain some of the natural properties of native cellulose even in nano-dimensions. The morphological parameters were analyzed using atomic force microscopy which confirmed the formation of nanocrystals. Using these novel nanocrystals, poly vinyl alcohol (PVA) nanocomposite films were prepared and characterized for elucidating their properties. The addition of nanocrystals has significantly improved the thermal stability and mechanical properties of PVA nanocomposites. Results of this study demonstrated that nanocrystals obtained by HCl have several advantages in the fabrication of high performance polymer nanocomposite films for food packaging applications.
Preparation and Nanomechanical Characterisation of Metal Containing Amorphous Hydrogenated Carbon Nanocomposite Films
Authors: Bharathy P. Vijai , Nataraj D. , Yang Q. , Mangalaraj D. , Kiran M.S.R.N.
Published: August 2010

The relationship between metal-induced chemical bonding and the mechanical properties of Me/a:C-H (Me- Ti and Ni) films are discussed. Nanocomposite films were deposited onto the Si substrates via biased target ion beam sputtering of metal combined with reactive ion beam deposition of a:C-H using CH4/Ar gas mixture. The chemical composition, microstructure and mechanical properties were characterized using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and nanoindentation. XPS analysis revealed that both Ti and Ni atoms were preferentially bonded to carbon to form its metal carbide phase. Irrespective of its kind, both the metal carbide clusters induces more graphite like bondings in a:C-H matrix. From the nanoindentation analysis it was found that there is no crack propagation and damage around the indent region even at very high indentation loads. Additionally, it was found that a:C-H film shows higher hardness compared to that of Ti/a:C-H and Ni/a:C-H films.
Small Punch Test of LC4/SiCp Metal Matrix Composites
Authors: Mak Jonathan , Wuhrer Richard , Humphries Sam R. , Booth Norman , Heness Greg , Yeung Wing Yiu , Wei Tao , Qin Ji Ning , Ouyang Qiu Bao , Zhang Di
Published: August 2010

There have been growing demands of high performance metal matrix composites in advanced engineering applications in virtue of their high specific strengths. This paper is to report an assessment of the mechanical properties of LC4/SiCp metal matrix composites using an innovative testing technique, small punch test. The composite materials of this study were produced by stir casting method with particulate reinforcements of 7wt.% and 14wt.% of SiC respectively. Small punch testing was performed on the LC4 base alloy and the two composites materials. The small punch test is a relatively new mechanical testing technique capable of utilizing small disk-shaped samples to determine the mechanical properties of the test materials. In this study, the equivalent fracture strain, εqf of the LC4/SiCp MMCs was characterised and compared with the base alloy. The fracture mechanism of the test samples was examined using scanning electron microscopy.
Study of Static Characteristics of Delaminated Composite Conoidal Shell Subjected to Point Load
Authors: Kumari Suman , Chakravorty Dipankar
Published: August 2010

Delamination is one of the most common modes of defects of laminated composite shell roofs. A review of literature that exists on composite shells reveals that the research reports on delaminated shells are very few in numbers. Present paper deals with the static analysis of delaminated composite conoidal shells with simply supported boundary condition and subjected to centrally applied point load. For the present study work a finite element approach using eight noded isoparametric shell element with five degrees of freedom per node is employed. A multipoint constraint algorithm is incorporated, to satisfy compatibility of deformation and equilibrium of forces and moments, which leads to unsymmetrical stiffness matrix. This formulation is validated through solutions of benchmark problems. Lamination and extent of delamination area are varied to compare the performances of delaminated conoidal shells against those with no damage. Based on the present comparison some engineering conclusions are also included in this paper, which will serve as future reference.
Development of Advance Thermal Barrier Coating in Gas Turbine
Authors: Choi Choul Jun , Lee Jung Ki , Kwac Lee Ku , Kim Jae Yeol
Published: August 2010

Combustion gas of gas turbine is about 1100 ~ 1300 °C. Is doing TBC(Thermal Barrier Coating) on the base metal surface to protect rotor or blade from high temperature flame. TBC system reduced heat transfer as metal base metal. TBC system is divided by bond coating of prevent oxidation and corrosion and Top coating reduced of heat transfer by high Temperature flame.
The objective of this study was to development of an advance TBC system for high Temperature (>1350°C) gas turbine components. Used coating powder developed newly in coating process, and more than 1350°C by parameter control in usable coating method develop. Internal studies looked at the effect of TBC coating thickness, material chemistry, substrate composition, surface temperature and bond coat as-sprayed surface profile/particle size on technical performance.
Effect of Z-Pin on the through-the-Thickness Strength of Woven Composite Laminates
Authors: Son J.H. , Chun Heoung Jae , Kang K.T. , Lee H.Y. , Byun Joon Hyung , Um M.K. , Lee S.K. , Kim Byung Sun
Published: August 2010

Delamination failure occurs due to the out-of-plane loading because of the weakness in the thickness directional properties of composite materials. The z-pinned composite has been developed to overcome such a problem. In this study, the mechanical properties of z-pinned composite laminates were examined using the analytical model. The effects of z-pins on the strength in the thickness direction were investigated. Fibers in the laminate are gradually waved by the formation of resin rich zone caused by inserting the z-pins. A constitutive model was developed for the predictions of strengths of woven z-pinned composites. The changes in the strengths in the in-plane and out-of-plane directions of the woven z-pinned composites and the effects of controlling parameters such as the diameter of z-pin and densities of z-pin on the strengths were identified. It was found that the out-of-plane tensile strength increases 14% relative to that of composite without z-pins when the diameter of z-pin is 0.25 mm. However, the in-plane tensile strength and in-plane and out-of-plane shear strengths were reduced to 9%, 7% and 8%, respectively, over the strengths of composite without z-pins. Qualitatively good correlations are obtained between the results of the suggested model and the experiments.
Thermal Resistivity Properties of LED Packages with Thermal via
Authors: Lee Hyo Soo , Shin Hyeong Won , Jung Seung Boo
Published: August 2010

The LED chips, packages and related materials have been already key issue on electronic applications and substitution of conventional lights. It is easily expected that the development trend of LED products is nearly the same as that of electronic products with higher performance, higher integration, lower energy and lower cost. And then we also prospect that the dissipated heat from LED chip is to be big problem for a reliability of products, as likely that electronic packages contain heat sink or heat spreader for controlling heat dissipation. In fact, the heat from an LED package with 1~3W LED chip shows a nearly 60~150°C, which affects thermal damage related to performance, joint failure, crack, etc. The thermal via was fabricated with 16 segments of via sizes ranged 0.2~1.2mm and via pitches ranged 0.5~3mm using 1~3W LED, respectively. The thermal resistivity was analyzed by the thermal transient tester with the variation of via sizes and pitches, which was also compared with the temperature difference of the top and bottom side of LED package. As a results, we convincingly proved the relationships between the design of thermal via and the heat dissipation of LED module, which were directly applicable to LED industry.
Formation of Resin-Rich Zones in Composites Processing
Authors: Dong Chen Song , Tsai Tze Chiun
Published: August 2010

Resin-rich zones are a common phenomenon in liquid composite molding processes. These resin-rich zones cause unwanted residual stress and deformation, and part-to-part variation, and thus they need to be studied in the design of composite structures. An experimental study on the formation of resin-rich zones in angled composite parts is presented in this paper. Two open-channel mold sets were designed and fabricated. Fiber preforms were loaded into these molds and the gaps formed were visually inspected by a microscope. The influences of corner radius, fiber volume fraction, enclosed angle, and stacking sequence were investigated, and significant factors affecting gap thickness were identified by Design of Experiments (DOE). It can be concluded from the experimental results that:
1) Fiber volume fraction is the most significant factor affecting gap thickness. Gap thickness is inversely proportional to fiber volume fraction;
2) Gap thickness is inversely proportional to radius;
3) The gap thickness of unidirectional preforms is larger than that of the cross-ply preforms.
Effects of Surfactant Content and Clay Content on Properties of NR Nanocomposites
Authors: Keawkumay Chalermpan , Jarukumjorn Kasama , Suppakarn Nitinat
Published: August 2010

Montmorillonite (MMT) was modified by octadecylamine (ODA) surfactant. The surfactant contents were varied, i.e. 0.5, 1.0 and 2.0 times the cation exchange capacity (CEC) of the MMT. XRD and FTIR spectra of the organoclay revealed that ODA molecules intercalated into MMT layers. The MMT-ODA was melt-mixed with natural rubber (NR) using a two roll mill. Effects of surfactant content and organoclay content on cure characteristics, mechanical properties, and morphologies of NR nanocomposites were investigated. Morphologies of the NR nanocomposites, with increasing surfactant content, revealed the exfoliated structure and the good dispersion of the organoclay in the NR matrix. These caused the enhancement of mechanical properties of the NR nanocomposites. With increasing the MMT-ODA2 content up to 5 phr, scorch time and cure time of the NR nanocomposites decreased while their tensile strength increased.
Numerical Analysis on the Compressive Behaviors of Aluminum Foam Material Using Computed Tomography Imaging
Authors: Kim Sang Hoon , Chung Hyup Jae , Rhee Kyong Yop
Published: August 2010

In the present study, we used computed tomography (CT) images of aluminum foam material obtained by an industrial volume CT system for a numerical analysis of the compressive behavior of the material. A three-dimensional model of aluminum foam was developed by stacking the CT images. The simulated and experimental compressive behaviors were compared. In particular, the simulated compressive behaviors were compared with those of experiments using various strain rates in order to verify the accuracy of the three-dimensional model. The results showed that the simulated compressive stress-strain curve displayed a similar tendency to that of the experiment, but had a higher compressive strength. The results also showed that the simulated compressive deformation pattern displayed a similar tendency to those of the experiments for all strain rates, and the deformation was significantly affected by the simulation of pore shape and size.
The Kinetic Description for Solid State Phase Transformation
Authors: Ma Ya Zhu , Liu Feng
Published: August 2010

The progress of solid-state phase transformation can be subdivided into three overlapping mechanisms: nucleation, growth, and impingement. On the basis of an analytical phase transformation model, the maximum in the transformation rate of an isothermal solid-state transformation has been evaluated. Then, the mode of nucleation, growth and impingement, and the separate activation energies for nucleation and growth can be determined. Finally, application in the crystallization kinetics of amorphous alloy was described.
2-D ZnO Nanostructures on Aluminum by Solution Method
Authors: Su Yi , Zou Xiao Ping , Meng Xiang Min , Teng Gong Qing
Published: August 2010

Two-dimensional ZnO nanostructures with various morphologies were synthesized on aluminum by solution method at 90°C. In our experiment, 0.1M zinc chloride (ZnCl2) was used as a ZnO precursor, and different volume of ammonia solution (25％) was added to the solution. We characterize the morphology and nanostructure of 2-D ZnO nanostructures and study the growth mechanisms of these 2-D structures. It should be noted that the existence of Cl﹣ plays an important role on the formation of 2-D structures.
Characterization and Photocatalytic Activity of La1.6Ln0.4Zr2O7 (Ln= La, Nd, Dy, Er) Nanocrystals by Stearic Acid Method
Authors: Tong Yu Ping , Zhao Shun Bo , Li Feng Lan , Li Chang Yong
Published: August 2010

La1.6Ln0.4Zr2O7 (Ln= La, Nd, Dy, Er) nanocrystals were prepared by stearic acid combustion method. The samples were characterized by powder X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) nitrogen adsorption, transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The photocatalytic activity of La1.6Ln0.4Zr2O7 was evaluated by the photocatalytic degradation of methyl orange. The order of the photocatalytic activity was as following: La1.6Er0.4Zr2O7>La1.6Dy0.4Zr2O7> La1.6Nd0.4Zr2O7> La2Zr2O7. La1.6Dy0.4Zr2O7 showed that the best photocatalytic activity and the reason may be related to the big magnetic moment of Er3+. It may be considered largely to be caused by the partly occupied Ln4f levels. Since the solid samples have the same structure, the reason that La1.6Er0.4Zr2O7 shows the highest reactivity may be related to lowest Ln4f level of Er3+.
Crystallization Mechanism of Si/Cu100-xZrx Bilayer Film for Write-Once Blue Laser Optical Recording Media
Authors: Ou Sin Liang , Kuo Po Cheng , Hsiao Chih Hsiang , Chiang Don Yau , Lee Chao Te , Tang Wei Tai
Published: August 2010

Si/Cu100xZrx (x= 0~38.1) bilayer recording thin films were deposited on nature oxidized silicon wafer, and glass substrate by magnetron sputtering. The ZnS-SiO2 films were used as protective layers. We have studied the thermal property, optical property, and crystallization mechanism of the Si/Cu100-xZrx bilayer thin films. The optical contrasts of the Si/Cu100-xZrx (x= 0~38.1) bilayer films under 405 nm wavelength are all larger than 15%, and it reaches a high value of 40%, as x= 38.1. This indicates that the Si/Cu100-xZrx (x= 0~38.1) bilayer films are suitable for blue laser optical recording.
Effect of Thicknesses on the Microstructure and Magnetic Properties of CoPt Thin Films
Authors: Shen Chih Long , Kuo Po Cheng , Lin G.P. , Li Y.S. , Ou Sin Liang , Chen Sheng Chi
Published: August 2010

The microstructures and magnetic properties of CoPt thin films with thicknesses between 1 and 20 nm deposited on amorphous glass substrate and post-annealing at 600°C for 30 min were investigated. The morphology of CoPt thin film would change from a discontinuous nano-size CoPt islands into a continuous film gradually as the film thickness was increased from 1 to 20 nm. The formation mechanism of the CoPt islands may be due to the surface energy difference between the glass substrate and CoPt alloy. Each CoPt island could be a single domain particle. This discontinuous nano-island CoPt recording film may increase the recording density and enhance the signal to noise ratio while comparing with the continuous film. The as-deposited 5 nm CoPt film revealed the separated islands morphology after annealing at 600°C for 30 min. This nano-size CoPt thin film may be a candidate for ultra-high density magnetic recording media due to its discontinuous islanded nanostructure.
Fabrication of Arrays of Zinc Oxide Micro/Nano Pillars in Aqueous Solution under an External Electric Current
Authors: Yang Gang Qiang , Zou Xiao Ping , Meng Xiang Min , Teng Gong Qing
Published: August 2010

Arrays of zinc oxide (ZnO) micro/nano pillars have been synthesized on indium-tin-oxide (ITO) substrates by a solution route under an external electric current. They were pillar-like morphologies and grew along the c-axis. Some comparative experiments showed that applying the external electric current effectively improved the alignment of the product in a short time. It was indicated that the micro/nano pillars can be obtained in a short time under an external electric current.
GeCu/Si Bilayer Thin Film for Write-Once Blue Laser Optical Recording Media
Authors: Ou Sin Liang , Kuo Po Cheng , Chiang Don Yau , Yeh Chin Yen , Ma Shih Hsien , Tang Wei Tai
Published: August 2010

GeCu(6 nm)/Si(6 nm) bilayer recording thin film was deposited on nature oxidized silicon wafer and polycarbonate substrate by magnetron sputtering. The ZnS-SiO2 films were used as protective layers. We have studied the thermal property, crystallization mechanism, and recording characteristics of the GeCu/Si bilayer thin film. Thermal analysis shows that the GeCu/Si bilayer film has two reflectivity changes with the temperature ranges, 120 °C ~ 165 °C and 310 °C ~ 340 °C. The results of dynamic tests show that the optimum jitter values at recording speeds of 1X and 4X are 5.8% and 5.9%, respectively. The modulations at 1X and 4X recording speeds are all larger than 0.4.
Hydrous Ruthenium Oxide Coating on SWCNT Substrate for the Electrode of Supercapacitor
Authors: Lin Yu Li , Peng W.Z. , Hsu Cheng Yi
Published: August 2010

In this study, single-wall carbon nanotube (SWCNT) mixed with hydrous ruthenium oxide was co-deposited on titanium substrate by cathodic deposition method. Titanium substrate was first cleaned thoroughly by acetone and followed by chemical etching of 5%HF for 5 minutes and 50%HCl for 15 minutes. The purpose of acid etching is to increase the adhesion between the coating layer and the Ti substrate. SWCNT has been dispersed by ultrasonic method to avoid agglomeration during deposition processes. The concentration of SWCNT added in the deposition process was 0.05 wt%. The time of specimens which were immersed into the deposition bath is varied from 5minutes to 60 minutes. The electrical capacity characteristics of specimen were examined by cyclic voltammetry. The microstructure of hydrous ruthenium oxide coating is elucidated by high resolution transmission electron microscopy (HRTEM). Combination of amorphous and nanocrystalline structure of hydrous ruthenium oxide was investigated in this study. Nano-sized particles (about 2-3nm) were found embedded in the amorphous matrix. The capacitance was found increased when the deposition time was increased. The maximum capacitance of hydrous ruthenium oxide coating was measured to be 556.7F/g.
Advanced Conductive Composite Materials for Spacecraft Application
Authors: Lee Ho Sung
Published: August 2010

In this study, thermal responses of advanced fiber/epoxy matrix composite materials are considered for spacecraft thermal design. These thermal responses are important, because the localized thermal behavior from applied heat loads can induce thermal stresses, which can lead to functional failure of the spacecraft system. Since most of polymer matrices exhibit relatively poor thermal conductivity, the composite materials have been widely considered only for structural application and little for thermal application. However, recently pitch-based high performance carbon fiber becomes available and this fiber shows high thermal conductivity. Because of this combination of low CTE and high thermal conductivity, continuous carbon fiber composites make them suitable for thermal management of spacecraft. The advanced composite material is composed of a continuous high modulus pitch based fiber (YS90A) and DGEBA epoxy resin(RS3232). It was demonstrated that advanced composite material satisfied thermal requirement for a lightweight thermal radiator for heat rejection of communication satellite.
Nano Positioning Control for Ultra-Precision Machining Using Inverse Hysteresis Model
Authors: Kwac Lee Ku , Kim Hong Gun
Published: August 2010

In this study, inverse-hysteresis model, which can inversely calculate input voltage for desired displacement, is suggested for tracking performance. In this paper, tracking performance and movement precision of piezoelectric actuator as operating parts of ultra-precision cutting unit is improved using feedback control of inverse-hysteresis model to remove hysteresis property. PID feedback control is studied as controller to compensate the error in inverse-hysteresis model. In addition, straightness error of spindle, thermal expansion error of mechanical structure is analyzed to detect movement error property in ultra-precision machining. Via machining performance evaluation using ultra-precision machining experiments, the machining precision of ultra-precision CNC lathe can be improved.
Nano Structure and Properties of Beta–D-Poly-Glucopyranose
Authors: Figovsky Oleg , Ioelovich Michael
Published: August 2010

Beta–D-poly-glucopyranose is widespread class of the natural semi-crystalline polysaccharide known as cellulose. This polymer has complicated multi-level supermolecular structure. It is built from elementary nano-fibrils and their aggregates; moreover, each nano-fibril contains ordered nanocrystallites and low-ordered amorphous nano-domains. Therefore cellulose can be a pronounced and eminent representative of nano-structured matters. Such nano matter has peculiar physico-chemical properties depending on specific surface of nano-scale constituents. In this paper, physico-chemistry of the nano-structured cellulose is discussed. In particular, the ability of nano-scale crystallites to co-crystallization and aggregation, as well as their ability to phase transformation through dissolution, alkalization and chemical modification was a subject of the investigation. Structural characteristics of paracrystalline surface layers of nano-crystallites and their effect on physico-chemical properties of the polysaccharide have been discussed.
Synthesis and Characterization of Nanocomposites Based on Copolymers of POSS-ONDI Macromonomer and TFONDI: Effect of POSS on Thermal, Microstructure and Morphological Properties.
Authors: Gnanasekaran D. , Reddy B.S.R.
Published: August 2010

Polyhedral oligomeric silsesquioxanes (POSS) possessing 7-oxanorbornene-5, 6-dicarboximide (POSS-ONDI) functionalized macromers are synthesised and well characterized using FT-IR, 1H, 13C and 29Si-NMR spectroscopic techniques. The homopolymer of [N-3(trifluoromethyl)phenyl-7-oxanorbornene-5,6-dicarboximide] (TFONDI) and a series of linear copolymers between [N-(POSS)-7-oxanorbornene-5, 6-dicarboximide] POSS-ONDI and TFONDI are prepared through ring opening metathesis polymerisation (ROMP) using Grubbs catalyst. All the polymers are characterized using FT-IR, 1H-NMR, TGA, DSC, AFM, TEM, XRD and GPC techniques.
Synthesis of Nanosized Phases from an Atomic Carbon
Authors: Sobolev Valeriy V.
Published: August 2010

Processes of atomic carbon formation can be initiated the most different energy sources – from strong shock waves to electric field of univalent ion. In the system, consisting of atomic carbon, there are fluctuations of energy and density, which result in the spontaneous origin of new solid phases.
The Efficiency on Mechanical and Thermal Characteristic in Polyurethane/Silica Nanocompounds
Authors: Wu Te Hsing , Chou Chih Wei , Shen Lie Hang
Published: August 2010

The object of this paper is to study the effect of silica nanoparticles (SiO2 NPs) on waterborne polyurethane films (5×10-3 to 5wt % SiO2 NPs). The Nanocompounds’ properties were analyzed by thermogravimetric analyzer (TGA), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and dynamic mechanical analyzer (DMA). From the results, the nanocomposites degraded at a higher temperature than pure PU matrix. Moreover, the temperature where the weight loss reached 50% was shifted by 57oC towards higher temperature when the silica nanoparticle content was 5 wt%. The crystallinity, mechanical strength as well as thermostability the PU were influenced by the concentration of silica nanoparticles.
Design of Fiber Bragg Grating Acoustic Sensor for Structural Health Monitoring of Nuclear Power Plant
Authors: Lee Jung Ryul , Chong See Yenn , Yun Chang Yong , Sohn Hoon
Published: August 2010

Nuclear power plant (NPP) is commonly categorized as a harsh environment that gives rise to age-related degradation on the structures of plant and eventually leads to radiation leakage that threatens human. Integrated structural health monitoring (ISHM) technology is a strong candidate for NPP accidents. The emergence of optical fiber technology into SHM system for NPP was greatly interested by researchers, and also prior research works have shown that the fiber Bragg grating (FBG) was able to retain its reflectivity under radiation exposure. In this paper, a metal-coated fiber was newly used to develop a FBG acoustic sensor for ISHM of NPP. The 7 mm length of aluminum, copper/carbon coatings were successfully removed with sodium hydroxide and nitric acid solutions. A 5 mm FBG was successfully inscribed in the silica core through the 7 mm long coating-removed silica section of copper/carbon-coated fiber and the initial reflectivity was 71%. Then, the FBG acoustic sensor was developed in one-end-free FBG configuration on the stainless steel vessel using a high temperature metallic adhesive. The reflective power of the sensor was stabilized at 345°C during the high temperature elevation cyclic process. The FBG acoustic sensor showed good response to the acousto-ultrasonic waves during pencil-lead breaking and laser ultrasonics tests. The high temperature FBG acoustic sensor written in the cost-effective metal/carbon is feasible to be used for ISHM of the NPP.
Finite Element Analysis of Mass-Spring System for Measurement of Relative Moving Displacement
Authors: Lee Yeon Gwan , Park Sang Oh , Jang Byeong Wook , Kim Yoon Young , Kim Chun Gon , Kim Dae Hyun
Published: August 2010

Most accelerometers are composed of a mass, a spring, and a damper. The quantification of the acceleration could be obtained from the equation of dynamic motion expressed in terms of the relative moving displacement. Therefore, if the moving displacement of a seismic mass is inferred from the output signal of a single-degree-of-freedom (SDOF) system, the acceleration could theoretically be obtained by a deformation response factor expressed in the relation between relative displacement and excited acceleration. A reflective grating panel-optical fiber sensor can measure the relative displacement by the movement of the grating panel that is attached to the seismic mass. Ultimately, this research is intended for application to grating panel-optical fiber sensors. However, in order to fabricate the adequate probe for this sensing principle, microscopic rotation (< 0.007 degree) should be prevented for stable reflectivity. Therefore, this paper describes the optimum design of the mass-spring structure which features a larger linear motion range of the leaf spring and no rotation of the seismic mass. Accordingly, finite element analyses (FEA) were accomplished for reflecting the grating panel-optical fiber sensor probe. The leaf spring was employed for the strict linear motion, and some parametric studies on the design of the leaf spring was conducted. First of all, in order to have flexibility in the leaf spring, the leaf spring is divided into N equal parts (N= 3, 4, 5). Furthermore, some parametric studies were carried out, including the length of the seismic mass, arm width, and length of the leaf spring, as well as the moment balancing design. Through the comparisons of each FEA result, the best design of the leaf spring was determined to obtain the optimum features over the measurement range of acceleration and frequency within the linear elastic of the leaf spring.
High-Speed Wavelength Interrogator of Fiber Bragg Gratings for Capturing Impulsive Strain Waveforms
Authors: Lee Bong Wan , Seo Min Seong , Oh Ho Guen , Park Chan Yik
Published: August 2010

It is highly desirable to increase the sampling rate of a fiber Bragg grating (FBG) interrogator in other to sense dynamic strains caused by impulsive acoustic wave. We have developed a wavelength interrogator featuring 100k samplings per second that consists of a solid-state spectrometer, a photodiode array and fully parallel read-out circuits. Central wavelengths on the reflected partial spectra corresponding to FBGs are calculated by the centroid method with the selected groups of the consecutive photodiodes at which each FBG spectrum is imaged. The centroid calculation is simple to be implemented in a field-programmable gate array (FPGA) and fast enough to capture impulsive strain waveforms in real time. Short-term noise on the interrogated wavelengths is estimated to be around 0.5 in terms of stain within the sampling bandwidth.
Photosensitization of Dye/TiO2 Thin Films by Using Natural Dye of TCPP
Authors: Lin Ching Hsing , Chang Chen Yu , Chang Yu Jie , Lee Yao Chuan , Hwa Mei Yin , Chang Yu Sen
Published: August 2010

The Dye-Sensitized TiO2 thin film fabricated by TiO2 nanoparticles is a novel technology with advantage in low cost, little pollution and simple in manufacturing process. The fiber-shaped reacting sites provide enlarged photo-sensing area of the TiO2 thin films. Natural dye of TCPP was applied to improve the photo absorbability in this study. Besides, a novel plasma surface activation technique employed on the thin film showed well performance compared with previous reports by heating methods. The SEM images demonstrate that the nano-TiO2 composites deposited on the fiber substrate. Degradation of acetone under 365 and 420 nm light irradiation were conducted to evaluate the photocatalytic ability of the TiO2 and TCPP/TiO2 thin films. While TiO2 thin films gel catalyst showed good photocatalytic performance with a high degradation efficiency of 99.9%, only about 80% conversion efficiency was achieved by the TCPP/TiO2 thin films reactor under 365 nm light irradiation. Although the TCPP dye on TiO2 nanoparticle shows beneficial reflection intensity in 420 nm, the acetone degradation capability of TiO2 and TCPP/ TiO2 thin films reactor decreased about 30% and 25% respectively compared with the degradation efficiency under 365 nm.
Anomalous Change of the Viscosity and the Structure of Sn Melt with Temperature
Authors: Yang Zhong Xi , Geng Hao Ran , Zhang Ning
Published: August 2010

On the basis of measuring the viscosity of Sn melt and referring to analysis of high temperature XRD, the change of viscosity and structure for Sn melt with temperature were carried out. The results show that there is discontinuous change of viscosity for Sn melt with the temperature. The state of Sn melt are divided into high, middle and low-temperature region according to the change of viscosity, and there is an anomalous point of viscosity change between different temperature region. There is a correlation between the viscosity change of and the structure change of Sn melt. The coordination number and correlation radius, and the fluid cluster size of Sn melt decrease with the increase of temperature, so that the viscosity of Sn melt decrease. But there is an anomalous change in the vicinity 673 K and 1073 K, it results in discontinuous change in viscosity of Sn melt.
Discovery of High-Performance Organic Non-Linear Optical Molecules by Systematic ‘Smart Material’ Design Strategies
Authors: Cole Jacqueline M. , Weng Ze F.
Published: August 2010

This paper presents the discovery of a range of high-performance organic non-linear optical (NLO) materials, that arises from ‘smart material’ design and systematic search strategies. This systematization circumvents the previous use of iterative discovery methods, which can only ever afford incremental improvements to currently known NLO materials, and they have no capacity to reveal entirely new classes of suitable NLO materials. This new approach employs data-mining, using the world’s repository of all published organic crystal structures as a representative set of chemical space. Two independent search strategies are implemented, each predicting the best organic NLO materials. The first search method relies on the concept of ‘molecular lego’, taking particular types of molecular fragments that are known to be important constituents of an NLO active material (the ‘lego’), and searching for these through chemical space, with the assistance of graph theory algorithms and systematic enumeration and classification. The second search method uses quantum- mechanical calculations to evaluate the molecular hyperpolarizability, β, of every organic molecule in the aforementioned database. Since β affords the intrinsic measure of NLO output, all organic molecules listed in descending order of  values reflects a ranked list of their NLO potential. The NLO properties of selected materials that are highly-ranked in these two lists were then tested experimentally, using Hyper-Rayleigh Scattering (HRS). The predictions are shown to be borne out by such experiments: HRS results show β0 (static hyperpolarizability) values that are up to 10 x greater than those for the industrial reference Disperse Red 1. Due to the commercial potential of these results, four new classes of NLO materials identified by this study have recently been patented.
Effect of Dent on Self-Sensing Method of CFRP
Authors: Todoroki Akira , Matsuzaki Roysuke , Samejima Yusuke , Hirano Yoshiyasu
Published: August 2010

Authors’ group has been done researches on the damage monitoring of the laminated Carbon Fiber Reinforced Plastic (CFRP) using the electrical resistance change method. The method adopts reinforcement carbon fibers as sensors, and it is called self-sensing method. Using thin CFRP laminates, delamination crack location and dimension are identified with the electrical resistance change method. However, the electrical resistance decreases when a delamination crack is made in a thick CFRP beam. The present paper experimentally investigates the effect of the dent for the measurements of electrical resistance change. Indentation tests are performed for the thick CFRP plates. The effect of the dent is calculated compared with the effect of piezoresistivity caused by the residual stress relief. As a result, the effect of the dent is larger than the effect of the residual stress relief for the thick CFRP. For the thick CFRP, dents cause the significant reduction of the electrical resistance in the thickness direction, and that causes electrical resistance decrease.
Electromagnetic Shielding Effectiveness and Manufacture Technique of Functional Bamboo Charcoal/Metal Composite Woven
Authors: Chen An Pang , Lin Chin Mei , Lin Ching Wen , Hsieh Chien Teng , Lou Ching Wen , Young Ya Hui , Lin Jia Horng
Published: August 2010

In order to fabricate textiles with electromagnetic shielding effectiveness (EMSE) and far infrared emissivity, we fabricated bamboo charcoal/metal (BC/M) composite wrapped yarns with metal wires (stainless steel wires or copper wires) as the core yarn and bamboo charcoal textured yarn as the wrapped yarns using a rotor twister machine. The optimum manufacture parameters included: the speed of the rotor twister was 8000 rpm and the wrapped amounts of the BC/M composite wrapped yarns were 4 turns/cm. The BC/M composite wrapped yarns were made into the BC/M composite woven fabrics using a loom machine. Moreover, we tested the BC/M composite woven fabrics in EMSE and then changed the lamination angles. When the lamination amount was 6, laminated angles were 0°/45°/90°/-45°/0°/45°, 0°/ 90°/0°/ 90°/0°/ 90°, and the frequencies of the incident waves were between 1.83 and 3 GHz, the EMSE of the BC/M composite woven fabrics reached 50 to 60 dB which was satisfactory.
Fabrication of Novel Wound Dressing
Authors: Chao Chieh Yu , Lou Ching Wen , Sung Hsing Wen , Chen Yueh Sheng , Lin Jia Horng
Published: August 2010

Sodium alginate (SA) is a polyanionic copolymer consist of mannuronic(M) and guluronic(G) sugar residues, it has been comment used in biomedical applications. In this research, polylactic acid (PLA) and Tencel fiber were fabricated into PLA/Tencel composite nonwoven fabric. Then the gel aqueous Ca-SA was combined with PLA/Tencel composite nonwoven fabric by three-dimensional (3D) coating method to form porosity coating layer. Then LMWCS was sprayed on the whole surface to form antibacterial layer. The physical properties of novel wound dressing were evaluated such as tensile strength, tear strength, water absorption rate, stiffness and SEM. In SEM observation result indicated, the coating layer performs highly porosity structure. Between coating layer and PLA/Tencel composite nonwoven fabric was combined by physical bonding. In this way, PLA/Tencel composite nonwoven fabric can remain some part of air permeability and also enhance the strength of dressing.
Magnetic Field Actuation of Shape Memory Nanocomposites
Authors: Golbang Atefeh , Kokabi Mehrdad
Published: August 2010

Shape memory polymers are stimuli-responsive materials able to adaptively store a temporary (deformed) shape and recover a ‘memorized’ permanent shape under an external stimulus. In shape-memory polymers, changes in shape are mostly induced by heating, and exceeding a specific switching temperature, Tswitch. If polymers cannot be warmed up by heat transfer using a hot liquid or gaseous medium, noncontact triggering will be required. In this article, the magnetically induced shape-memory effect of composites from NdFeB magnetic particles and crosslinked low density polyethylene (XLDPE) shape memory nanocomposite containing 2 wt% nanoclay is introduced. Various amounts of NdFeB particles (5, 15, 40 wt %) were added to the nanocomposite. Electromagnetically triggered shape memory properties of the formed composites were conducted using an alternative magnetic field with a frequency of 9 kHz and strength of 15 kW. The shape recovery of samples was possible by inductive heating and the shape recovery rates comparable to those obtained by conventional heating methods were demonstrated. It was concluded that the maximum heat generation achievable by inductive heating in the alternative magnetic field depends on magnetic particle content. The sample containing 15wt% NdFeB reached a full shape recovery of 25% extension within 6 minutes remaining in the magnetic field.
Analysis of Roughness in Super-High Speed Point Grinding
Authors: Liu Yue Ming , Gong Ya Dong , Cheng Jun , Han Ting Chao
Published: August 2010

The technology of super-high speed point (SHSP) grinding will bring in higher precision and productivity for component manufacturing. The surface roughness attained by SHSP grinding is analyzed in this paper based on the contact area and the probability distribution of chip thickness while the swivel angle of α exists, proposing a new method to predicate the value of the roughness, the experiment of SHSP grinding is carried out whether α exists or not to verify the theoretical analysis in the paper, through observing the micro-surface after grinding, the conclusions will be drawn at last.
Grinding Performance of a Grain-Arranged Diamond Wheel against Aluminum Alloys and Ti6Al4V
Authors: Okuyama Shigeki , Yui Akinori , Kitajima Takayuki
Published: August 2010

A grain-arranged diamond wheel was developed and grinding performance of the wheel against aluminum alloys and titanium alloy, Ti6Al4V, has been investigated using various kinds of grinding fluid. Mirror finishing of aluminum alloys was successfully performed without grinding burn when emulsion-type grinding fluid with an extreme-pressure additive was used. When oil base lubricants or a fatty acid was supplied using a MQL supply unit, fine finishing could not be done. Mesh size of the grinding wheel had only a minor effect on surface roughness. When Ti6Al4V was ground by the developed wheel, an adhesion of work material on diamond grains occurred causing the finished surface to deteriorate.
Effect of Flexing on Coated Abrasive Belt Grinding of Stainless Steel
Authors: Kennedy Xavier , Gowri S.
Published: August 2010

Coated abrasives are extensively used for manual operations such us cleaning, deburring, polishing, etc. With the trend towards increased production rates, demands on coated abrasive belts are becoming increasingly severe. . Experimental investigations are to be made to know the effects of the process parameters on the performance of the surface belt grinding process. It is necessary to investigate the effect of flexing along with other input process parameters on output. In the present work the Taguchi’s experimental design method is used for performing the belt grinding process on the stainless steel AISI 304 and optimizing the process parameters. Thus, this research aims at right choice of flexing and grinding parameters for the coated abrasive belts. The results were further analysed by Taguchi’s signal to noise ratio for finding the optimum process parameters.
Surface Texture Analysis of Fixed and Free Abrasive Machining of Silicon Substrates for Solar Cells
Authors: Chen Chao Chang Arthur , Chao Pei Hsiun
Published: August 2010

Multi-wire sawing process has been widely used for wafer slicing of silicon substrates for solar cells. Usually there are two different kinds of wire saw in multi-wire sawing process including free abrasive wire sawing with SiC grits and fixed abrasive wire sawing with diamond wire. For free abrasive wire sawing process, the material removal mechanism can be considered as lapping and the fixed abrasive wire sawing can be considered as grinding. This paper is to investigate the characteristics of the surface texture of silicon substrate fabricated by these two wire sawing process. Experimental results have been observed by white light interferometry and SEM. Some different properties of both processes have compared been with variant characteristics including 2-D and 3-D surface roughness parameters. Results of this paper can be further used to evaluate the feasibility of wire sawing process of silicon substrates for solar cells.
On Geometrical Errors and their Suppression in Turning Operation by Controlling Thrust Forces
Authors: Miura Kohichi , Yamada Takazo , Lee Hwa Soo
Published: August 2010

In the case of turning workpieces having high aspect ratios, i.e. length divided by diameter, it is not so easy to obtain high cylindricity because of the elastic deformations due to the thrust forces taking place under operations. In this paper, the generating mechanism of geometrical errors is discussed and its suppressing method is proposed. That is, applying previously established controlling method of thrust forces to turning cylinders with high aspect ratios, it is confirmed that geometrical errors of workpieces due to the action of thrust forces can be suppressed.
Optimal Improvement on Cutting Yield Rate in ACF Attach Process of TFT-LCD Module Using Response Surface Method
Authors: Kuo Jian Long , Hsieh Chung Hao
Published: August 2010

In TFT-LCD manufacturing process, the ACF is an essential material. To make the driving circuit conductive, the ACF attach process is used in bonding process. Since the total manufacturing cost becomes lower year by year, the ACF material occupies a great deal of manufacturing cost. The boding technology has been changed from the conventional long bar type into short bar type to save the material usage. The parameter setting of the short bar type machine was not initially optimized. The NG rate of short bar type ACF attach process is higher as compared to the long bar type. The rework cost and material cost may increase in the short bar type process. Therefore, the parameter optimization for the associated short bar type ACF attach process becomes an essential problem. The response surface method is adopted to model the problem. The yield rate is selected as objective function for study. In the analysis of response surface method, the plasma clean speed, ACF peeling speed and ACF cutter spring setting are selected three key factors for discussion. Results reveal that the yield rate can be improved up to 99.35%, which is very helpful to improve the manufacturing process.
Comparative Studies on the Cutting Performance of HFCVD Diamond and DLC Coated WC-Co Milling Tools in Dry Machining Al/SiC-MMC
Authors: Shen Bin , Sun Fang Hong , Zhang Dong Can
Published: August 2010

The chemical vapor deposition (CVD) diamond and diamond-like carbon (DLC) films are deposited on the cobalt cemented tungsten carbide (WC-Co) cutting tools respectively using the hot filament chemical vapor deposition (HFCVD) technique and the vacuum arc discharge with a graphite cathode. The scanning electron microscope (SEM), optical interferometer profiler and Raman spectroscopy were adopted to characterize the as-deposited diamond and DLC films. The cutting performance of as-fabricated CVD diamond and DLC coated milling tools is evaluated in dry milling SiC particulate reinforced Al-metal matrix composite material (Al/SiC-MMCs), comparing with the uncoated WC-Co milling tool. The milling results demonstrate that the uncoated WC-Co milling tool suffers severest wear in its circumferential cutting edge, while the wear of DLC coated milling tool is slightly lower. Comparatively, the CVD diamond coated milling tool exhibits much stronger wear resistance. The wear on its circumferential cutting edge is less than 0.07 mm at the end of milling test, only a half of that of DLC coated milling tool. This result is attributed to the extremely high hardness and strong adhesive strength of CVD diamond film covered on the WC-Co milling tool.
Simulation of Grinding Surface Creation – A Single Grit Approach
Authors: Chen Xun , Tecelli Öpöz Tahsin
Published: August 2010

The paper presents an investigation of grinding material removal mechanism using finite element method. Understanding of grinding removal mechanism relies on the investigation of material removal by each individual grain. Although some analytical formulations have been developed to predict and to quantify the machining events in grinding, they do not illustrate every stage of abrasive actions. Finite element analysis provides good facility to present details of physical behaviour in grinding. In this research, material removal mechanism of grinding, namely rubbing, ploughing and cutting, is discussed with the variation friction coefficient. The major emphasis here is on the ploughing. Total force variation exerted during indention and sliding of a grain is also presented along its path.
Elastic and Plastic Behaviors in Ductile-Regime Machining Process of Quartz Glass
Authors: Takechi Takahiro , Tamaki Junichi , Kubo Akihiko , Sharif Ullah A.M.M.
Published: August 2010

Single-point fly cutting and nanoindentation test of quartz glass were performed using three different cutting tools, namely, a V-shaped cutting tool, a Vickers indenter and a spherical indenter, to investigate the elastic and plastic behaviors of quartz glass in ductile-regime machining. It was found that these behaviors depend on tool shape and that the V-shaped cutting tool is most effective for removing quartz glass material followed by the Vickers indenter and spherical indenter.