bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of Core Position of Fiber Array by a Calibrated Mask Method
Authors: Hsu S.W. , Jiaan Y.D. , Huang M.S.
Published: March 2009

A method for obtaining the core positions of fiber array is described. The technique is based on the use of calibrated mask. Because the mask and the fiber array are simultaneously moved and imaged, the measuring system is relatively simple in image processing, location, and vibration isolation. A prototype system with common components has been built for testing a number of commercial fiber arrays.
An Ultraprecision On-Machine Measurement System
Authors: Ohmori Hitoshi , Watanabe Y. , Lin Wei Min , Katahira Kazutoshi , Suzuki T.
Published: March 2009

Ultraprecision optical components require ultra-fine smooth surface quality of sub-nanometer or sub-angstrom in Ra. To satisfy these requirements, ultraprecision on-machine measurement system is very important, by which the profile measurement and evaluation is conducted on the machine. The form accuracy is improved by compensating machining when the form accuracy is not enough. Ultraprecision on-machine measurement systems were developed for measurement with high-accuracy and high-efficiency. It was confirmed that the on-machine measurement with AFM was possible for surface roughness or complex form for local areas. In addition, a laser probe unit with a maximum resolution of 1nm, a measuring range of 10mm, a repeatability of 5.6nm and a maximum measurable angle of 60 degrees was developed. The possibility of the non-contact on-machine form measurement was confirmed for global form accuracy control.
Determination of Young's Modulus of Micromechanical Silicon Films Using an Acoustic Excitation and Optical Detection Resonance Method
Authors: Liu Y.M. , Tian W.J. , Zhang S.J.
Published: March 2009

The Young’s modulus of micromechanical silicon films is very different from bulk
silicon structures. It is very meaningful to test Young’s modulus of micromechanical silicon films in related studies. Owing to its small and fragile characterstics, a suitable non-contact and nondestructive method is needed to test the Young’s modulus of micromechanical silicon films with plate-like and beamlike structures. Utilizing acoustic excitation and optical detection method based on theoretical analysis, a new resonant method is presented to determinate Young’s modulus of micromachined silicon films. By using this novel method, more accurate results have been achieved and the measuring error is 11%, better than the reported 14%.
Observation of Scattered Evanescent Waves
Authors: Ozaki M. , Furutani Ryoshu
Published: March 2009

Spatial resolution in the conventional optical microscopy depends on diffraction limit. Photon scanning tunneling microscopy is one of the microscopic methods that surpass the diffraction limit. It scans an object with detecting evanescent wave on object surface. Evanescent wave is scattered by the tip of a fiber probe and guided to a detector by the fiber probe. Not all of the scattered ray can be detected. Only the scattered ray from the aperture of a fiber probe can be detected. We propose to improve an image by detecting the state of scattered ray and a new method to maintain the probe sample distance constant by keeping the quantity of scattered ray constant.
Electromagnetic Field Analysis and Measurement for High Speed Attraction Type Magnetic Levitation Vehicle Systems
Authors: Chen D.X. , Pan M.C. , Luo F.L. , Kang Z.W. , Tian W.G. , Hu Yun Yu
Published: March 2009

Research achievements in a high speed attraction type magnetic levitation vehicle experimental system are reported. The high speed attraction type magnetic levitation vehicle constitutes a typical long stator linear synchronous motor. The study on levitation and propulsive electromagnetic fields is of great importance and is studied. Owing to the influence of the stator grooves and the material discontinuousness, the magnetic field distribution is very complex to be analyzed in analytical forms. The magnetic fields in the air gap are determined using the finite element method. The levitation force and thrust produced by the levitation magnetic field and the propulsive magnetic field are calculated. They are found to vary following the change of the air gap and exciting current. A magnetic field strength measurement system based on a hall sensor is designed. Experimental results are compared with the results from the magnetic field analysis.
Dielectric Spectra of BaTiO3-Based Ceramics Measured by Impedance Analyzer Using Micro Planar Electrodes
Authors: Li Jianyong , Kakemoto Hirofumi , Wada Satoshi , Tsurumi Takaaki
Published: March 2009

A new measuring method and analyzing procedure were proposed to determine the complex dielectric permittivity of materials with relatively high permittivity using an RF-impedance analyzer. Samples used for the measurement were (Ba0.6Sr0.4)TiO3 and Ba(Zr0.25Ti0.75)O3 ceramics. Micro planar electrodes were used for the measurement of complex admittance of these samples. Electromagnetic simulations were carried out for determining the relative dielectric permittivity and dielectric loss. The complex dielectric permittivity vs. frequency curves of Ba(Zr0.25Ti0.75)O3 showed a broad dielectric relaxation, while that of (Ba0.6Sr0.4)TiO3 was almost flat up to 3 GHz.
Enhancement on Proton Conductivity of Three-Dimensionally Ordered Macroporous Silica Membrane by Surface Sulfonation
Authors: Munakata Hirokazu , Chiba Hiroto , Dokko Kaoru , Hamagami Jun Ichi , Takei Takashi , Kanamura Kiyoshi
Published: March 2009

A new proton-conducting membrane was prepared consisting of uniformly macroporous silica matrix and a proton-conducting gel polymer, 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). Three-dimensionally ordered macroporous silica membrane was fabricated by use of a colloidal template method with mono-dispersed polystyrene beads. Surface sulfonation of the pores in the silica matrix was performed by using 1,3-propanesultone. The sulfonated silica matrix exhibited about 400 times higher proton conductivity than unmodified one. The proton conductivity of the composite membrane was also successfully enhanced by using the sulfonated silica matrix.
Barium Titanate Micropatterns Prepared by Electron Beam Lithography and Electrophoretic Deposition
Authors: Wu Yong Jun , Li Juan , Kuwabara Makoto
Published: March 2009

Electron beam lithography combined with electrophoretic deposition was investigated to fabricate micropatterned barium titanate (BTO) with nanostructures. High quality resist molds with micropatterns of microgrids and microdot arrays were prepared on Pt/Ti/SiO2/Si substrate by electron beam lithography. BTO nanocrystallites in a pseudo-cubic perovskite phase with an average particle size of about 10 nm were synthesized by a high-concentration sol-gel process. Well-dispersed and stable suspensions of barium titanate nanocrystallites were synthesized. Then, BTO microlines, microgrids and microdot arrays were electrophoretically deposited on micropatterned Pt/Ti/SiO2/Si substrate from these suspensions. The microstructure and properties of the BTO micropatterns were evaluated.
Preparation and Optical Properties of Epitaxial Pb(Mg1/3Nb2/3)O3-PbTiO3 Thin Film on Si Substrates with Buffer Layer Using Pulsed Laser Deposition
Authors: Nemoto Naru , Wakiya Naoki , Shinozaki Kazuo , Kiguchi Takanori , Satoh Keisuke , Ishii Masatoshi , Kondo Masao , Kurihara Kazuaki , Mizutani Nobuyasu
Published: March 2009

Epitaxial Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) thin films for electrooptic applications were fabricated on a Si substrate using buffer layers. The PMN-PT/SrRuO3/SrTiO3/(La,Sr)CoO3/CeO2 /YSZ/Si hetrostructure was fabricated by pulsed laser deposition. A PMN-PT thin film with a thickness of 2μm was successfully deposited. The optical characteristics of PMN-PT epitaxial film were measured by prism coupling method. The morphology of the PMN-PT films was drastically improved by introducing a mask between the target and substrate during the deposition. The PMN-PT thin film showed a columnar structure, where the width of each column was approximately 180nm. A refractive index of 2.48 with zero bias voltage was obtained for the epitaxial PMN-PT thin film using the prism coupler method.
Chemical Durability Investigation of Magnesium Phosphosilicate Cement
Authors: Ding Zhu , Li Zong Jin , Xing Feng
Published: March 2009

The magnesium phosphosilicate cement (MPSC) is a novel inorganic binder, it sets quickly and has very high strength. Also, it is a promising material for the sustainable development. In the present study, the durability of MPSC were investigated, including deicer scaling resistance under freezing-thawing cycles, chemical corrosion resistance in sodium sulfate and magnesium sulfate solutions, and wet-dry resistance in fresh and natural sea water. For comparison, Portland
cement samples were also prepared for parallel tests. Test results showed that the chemical durability of MPSC is superior that of Portland cement. The causes of the high performance may be attributed to the low water demand and a reasonable microstructure of hardened paste matrix.
Effects of Styrene-Acrylate Emulsion on the Damping Ability and Hydration of Cement Matrix
Authors: Liu Tie-Jun , Ou Jin Ping
Published: March 2009

Cement mortar of high damping ability has been maded by using styrene-acrylate
emulsion as an admixture. The addition of styrene-acrylate emulsion causes the loss tangent of plain cement mortar to increase at all temperature (-30-30 °C) and frequencies (0.1-2.0 Hz), and the loss tangent increase is particularly large at 15-30 °C, even up to 0.25 at 30 °C and 0.5Hz due to the glass temperature of styrene-acrylate emulsion, although the storage modulus of cement mortar with this admixture decreases at all temperatures and frequencies, however, for the loss modulus, which serves as an comprehensive figure-of-merit for the vibration reduction ability, styrene-acrylate emulsion may dramatically increase it. The X-ray diffraction (XRD) and infrared (IR) spectrum analysis have provided evidence that styrene-acrylate decelerates the hydration of cement paste.
Relationship between Test Results of the ACSIRO and ASTM C1202 Methods
Authors: Li Wei Wen , Leng Fa Guang , Yuan Xiong Zhou
Published: March 2009

The ASTM C1202 method is observed that the total electric charge passed is not an ideal indicator for classification of concrete quality when different binders are considered. Considering the drawback of the ASTM 1202 method, a simple modification to the ASTM C1202 method is recommended. The modification involves an additional test using curing water as electrolyze solution. The difference in the total charge passed obtained between standard test and test performed in curing water is suggested as an indicator for concrete quality. The test results show that there exists a good correlation between the ACSIRO and the ASTM C1202 methods. The relationship can be formulated as a linear function.
Ductility of Partially Prestressed Concrete Beam
Authors: Du Jin Sheng , Chang Xue Liang
Published: March 2009

Ductility of partially prestressed concrete beams was numerically analyzed. For a given value of reinforcement index, corresponding curvature ductility factors of an unbonded prestressed concrete beam as well as a bonded prestressed concrete beam are analyzed and compared. It is generally observed that, when reinforcement index is between 0.20 and 0.30, the ductility factor of an unbonded beam is higher than that of bonded one about 10 to 15 percent. While reinforcement index is between 0.15 and 0.20, the ductility factor of an unbonded beam is near that of bonded one. When reinforcement index we is smaller than 0.15, the ductility factor of an unbonded beam is usually lower than that of bonded one about 10 to 15 percent.
Form and Texture Control of Free-Form Surface Polishing
Authors: Ji Shi Ming , Zhang Xian , Zhang Li , Yuan Qiao Ling , Wan Y.H. , Yuan Ju Long
Published: March 2009

In this paper, a new type of flexible sub-size polishing tool, and an advanced polishing technique for free-form surface based on the new type of tool will be researched. The configuration of the flexible polishing tool and the method of controlling the multi-DOF precessions of the flexible polishing tool will be introduced. The rectilineal movement along X,Y, Z axis and flirts on two polar coordinates rotational axis of the polishing tool are used to control the form precision and the surface texture of polished surface. This polishing technique is enable to change continuously the polishing pressure and contact area and makes the flexible polishing tool well suited both to control the texture of work-piece surface and to control the form of work-piece surface. The influence functions the flexible polishing tool is near-Gaussian, symmetrical, and lacks the high spatial frequencies and
center-zero of removal. The example of multi-DOF precessions polishing for optic spherical and aspherical will be introduced. The results show that the form, the size and the movement mode of the polishing tool will have important effect to polishing quality and multi-DOF precessions polishing can obtain better surface texture quality, form precision and higher polishing efficiency than traditional pole-down polishing for free-form surface.
The Study on Ductile Removal Mechanisms of Ultrasonic Vibration Grinding Nano-ZrO2 Ceramics
Authors: Zhao Bo , Wu Yan , Liu C.S. , Gao A.H. , Zhu Xun Sheng
Published: March 2009

On the basis of analyzing the brittleness, ductileity, and the removal mechanisms of the^nano-ZrO2 Ceramics, the critical ductile grinding depth formula of the nano-ceramics was established. Due to superductileity of the nano-ZrO2 ceramics, it couldn’t apply the formula of the common engineering ceramic material according to experimental results. The value of material coefficient ζ has relations with not only the material characteristics but also the processing methods and the processing parameters. It was proved that ζ has great effects on the accuracy of theoretical
calculation. Experimental results showed that the critical ductility grinding depth of the nano-ZrO2 ceramics is up to 12 µm in common grinding methods, while in ultrasonic grinding is up to 20µm. The grinding chips with and without ultrasonic vibration assistance were discussed.
A Fundamental Study on Optimal Oxide Layer of Fine Diamond Wheels during ELID Grinding Process
Authors: Dai Y. , Ohmori Hitoshi , Lin Wei Min , Jiang D.
Published: March 2009

In ELID (Electrolytic In-process Dressing) operations, the setting of starting point is quite important for reducing waste of time and for achiving high quality surface. In this study, the authors proposed a new describing mode for ELID grinding. The oxide layer formed on the wheel surface was divided to four sub-layer: porous-layer, polishing-layer, grinding-layer and interface-layer. The influence of the oxide layer on material removal rates and surface properties was investigated. It was found that, olny the oxide layer with thickness less than 24'm has capability of material removal. In ELID grinding, optimal thickness of the oxide layer is about 8~9'm. And the oxide layer with thickness of 4~9'm is suitable for grinding.
Study on Block Electrode Discharge Grinding of Micro Rods
Authors: Zhao Wan Sheng , Jia B.X. , Wang Zhen Long , Hu Fu Qiang
Published: March 2009

Block electrode discharge grinding is an effective approach to produce micro rods. However, it is difficult to fabricate the rods into desired miniature and precision. To solve this problem, the tangential feeding method is proposed to control the finish size of micro rods. With this method, the micro rod is first fed in its radial direction, and then in the tangential direction for an enough distance. The wear of the block electrode decreases gradually from the start to the end, and the wear in the end can be neglected. Experiments indicate that the large capacitance or voltage can obtain high machining speed, while the small ones can gain thin micro rods. Based on this result, the policy of delaminating grinding is adopted to gain enough thin micro rods at a high machining speed. The Φ5µm micro rods can be ground with this method. SEM results show that the relative error of the size control is less than 10%.
Study on Single-Plane Biaxial Balance Monitor System in ULTRA-Precision Grinding
Authors: Zheng L. , Guo Yin Biao , Wang Z.Z.
Published: March 2009

This paper puts forward an intelligent single-plane biaxial balance monitor system, which is used in ultra-precision grinding. It adopts the method of single-plane balance correction for the vibration of wheel and workpiece. And this system can also be used for integral balance. For ultra-precision grinding, caused by the mutual influence of the vibration of wheel and workpiece, there will be a ripple on the workpiece surface, which is mainly influenced by the frequency ratio of wheel to workpiece, the feed rate and the vibration of wheel and workpiece. This system can improve the machining accuracy, reduce the surface error of workpiece and appraise the integrated machining result, by analyzing the vibration data of wheel and workpiece and adjusting machining parameters.
The Influence of Structural Parameter on Resonance of the Vibrating Disk in Ultrasonic Honing System
Authors: Zhu X.J. , Zhang Q.S. , Wang A.L. , Gao H. , Xu Hong Jun
Published: March 2009

Vibration disk has certain influence on the resonance frequency of ultrasonic honing
vibration system when ultrasonic honing device is designed. The results of theoretical calculation are basically conformed to that of experiments, which have been investigated by means of experimental and theoretical calculation method. This study provides a basis for the development of ultrasonic honing device. Undergoing practice we can find that the efficiency ultrasonic honing system as above described can be extended and applied to production. The system is a typical non-conventional machining, but it can be applied not only to conventional honing machine , its technology effect as good as high precision machine tool , but also to developing and studying ultrasonic vibrating numerical controlling honing machine tool which will provide a new type, efficient, high quality low consumption, equipment for working precision hole.
Revolved Surface Finishing with Smart Fluid Abrasives
Authors: Sun Huan Wu , Yang Shu Cai
Published: March 2009

The smart fluid abrasive (SFA) is a suspension of magnetically soft ferromagnetic
particles and nonmagnetic abrasives in a carrier liquid. When the SFA is exposed to a magnetic field, a rapid and reversible fluid-to-solid phase transition occurs. Based on these distinctive features of SFA, a new type of precision finishing technology that can be used in the finishing of the revolved surface has been developed, and the finishing results have been proved in our experiments. In this paper, the SFA finishing mechanism and finishing process are presented, the influence of some basic parameters such as magnetic strength, size of abrasives, time of processing
and relative motion between abrasives and working surface of work pieces are discussed as well.
Bonds of Electroplated Diamond Tools for Optical Glass Machining
Authors: Yu Ai Bing , Wang A.J. , Luan C.G. , Chen S.F.
Published: March 2009

Bonds of electroplated diamond tools are investigated through the studies of
microstructures and properties. Three coatings for tool bonds, nickel, nickel-cobalt and bright nickel, were fabricated with electrodeposition processes, and were heat-treated with different temperatures. The hardness and microstructures of coatings were measured and observed. Optical glass K9 was machined with fabricated electroplated diamond tools to compare material removal rate and grinding ratio. The grain sizes of three bond coatings are different. The laminar structures of nickel-cobalt and bright nickel coatings turn to fine columnar structure after heat treatment
processes. With heat treatment of 200°C temperature, bright nickel electroplated diamond tool presents highest values of material removal rate and grinding ratio. The research results show that better microstructures and property of bond for electroplated diamond tool can be obtained by selecting proper electroplating technology and heat treatment processes.
Vibration Control of Smart Structures Using Piezofilm Actuators
Authors: Choi Seung Bok , Sohn Jung Woo
Published: March 2009

This paper presents vibration control of a flexible smart beam structure using a new
discrete-time sliding mode controller. After formulating the dynamic model in the space representation, so called the separation principle for equivalent controller is established so that the sliding mode conditions are satisfied. By doing this, undesirable chattering of the flexible structures can be attenuated in the settled phase. In order to demonstrate some benefits of the proposed methodology, an experimental realization is undertaken. Both transient and forced vibration control
responses are evaluated in time domain and compared between with and without the separation principle.
Flexural Fracture and Fatigue Behavior of RC Beams Strengthened with CFRP Laminates under Constant Amplitude Loading
Authors: Yao Guowen , Huang Pei Yan , Zhao Chen
Published: March 2009

Externally bonded carbon fiber reinforced polymer (CFRP) materials are well suited to the rehabilitation and reinforcement of civil engineering structures due to their high specific strength, specific stiffness and corrosion resistance. To probe the fatigue behavior of CFRP strengthened concrete structures, three point bending experiments of reinforced concrete (RC) beams strengthened with carbon fibre laminate (CFL) under constant amplitude loading were performed. The histories of
midspan flexibility and bending stiffness of strengthened beams were recorded automatically. And the linear curve between fatigue strength and the logarithm of fatigue life was obtained. The failure modes go through concrete cracking, CFL debonding from concrete and steel bars yielding and fracture with increasing cycles of fatigue loading. Bonded CFL increases the ductility of strengthened RC beam and results in dense distribution of cracks compared with normal RC beam, and it’s bending stiffness at damage state as well. The fatigue damage evolvement shows three stages of nucleation, steady expansion and failure. Then the failure mechanism was studied and a cumulative damage model was proposed to describe the fatigue damage and fracture process of CFL strengthened RC beams under constant amplitude loading.
An Experimental Study on the Shear Behavior of Perforated Shear Connector with Flange Head
Authors: Kim Y.H. , You S.K. , Jung Jae Ho , Yoon Soon Jong , Lee Seung Sik
Published: March 2009

Concrete-steel composite members are formed by bonding a steel component, such as an I-section beam, to a concrete component, such as a reinforced concrete slab, so that the two components can act as a unit. The use of such type of composite member becomes main stream of construction technology since it provides efficient load resisting mechanism in structural system. In a composite member, bond between steel and concrete is a crucial factor for the composite action.
Usually this bond behavior is achieved by installation of mechanical device so called shear connector. The composite action can be divided into two categories (i.e., full and partial) depending on the shear strength of mechanical shear connector embedded in the concrete, i.e., understanding of shear load resisting mechanism is necessary to develop a new shear connector for better, wider and more
efficient application of composite action. For this purpose, the push-out tests are performed for the evaluation of several existing shear connectors including carefully designed perforated shear connector with flange head. One of the purposes of this experimental research is to define the shear resisting mechanism of the proposed new type shear connector. The experimental results show that the degree of composite action using perforated shear connector with flange head is superior to those of existing shear connectors such as a general headed stud, perfobond, etc. The experimental parameters, such as the number of perforated holes, the distance between perforated holes, and the height of shear connector, are carefully chosen for the verification of their effect on the capacity of shear resistance. From this experimental investigation it was found that the mechanical performance
of proposed shear connector was efficient as a rigid shear connector.
A Study on the Flow and Thermal Stress Analysis of the Hot Gas Casing of the Gas Turbine
Authors: Choi Young Jin , Lee Young Shin , Kim Jae Hoon , Park Won Shik , Kim Hyun Soo
Published: March 2009

The hot gas casing of the gas turbine has operated in high temperatures and thermal
gradients. The structure safety of hot gas casing will be highly depend on the thermal stress. In this paper, flow and thermal stress analysis of the hot gas casing is carried out using ANSYS program. The obtained temperature data by flow analysis of hot gas casing is applied to the load condition of the thermal analysis. The thermal stress analysis is carried out the elastic-plasticity analysis. The pressure, temperature and velocity of the flow and thermal stress of the hot gas casing are presented
Fatigue Behavior of Impacted Carbon/Epoxy Laminates under 2-Stage Block Loading
Authors: Kang Ki Weon , Kim Jung Kyu , Kim Yong Su , Do Young Min
Published: March 2009

The paper presents the fatigue behavior of carbon/epoxy laminates with impact-induced damage under 2-stage block loading. The impact damage parameter is proposed to evaluate the effect of impact damage on fatigue life. Based on this parameter, the model is developed to predict the residual life at second block. Also, the model for equivalent stress is proposed to estimate the fatigue life under 2-stage block loading based on the S-N curves under constant amplitude loading. For these
models, the 2-stage block loading fatigue tests were performed on the impacted composite laminates. The effect of impact damage on fatigue life under 2-stage block loading can be characterized by the impact damage parameter. Additionally, the results by the present residual life prediction model agree with experimental results regardless of applied impact energy. Also, the equivalent stress and corresponding fatigue life by the present model agrees well with the experimental results.
The Strain Energy Release Rate of a Bi-Material Beam with Interfacial Crack
Authors: Her Shiuh Chuan , Su Wei-Bo
Published: March 2009

Multi-layer structures are common in electronic package especially for the micro devices manufactured via the semi-conductor processes or MEMS processes. Interfacial crack due to the delamination significantly weakens the multi-layer structure. It is desired to understand the interfacial fracture properties of the electronic packaging materials. In this research, three specimens named Doubled Cantilever Beam (DCB), End-Notched Flexure (ENF), and Four-Point-Bending are proposed to investigate the fracture toughness associated with mode I, mode II and mixed mode. Basing on the Euler-Bernoulli beam theory, the strain energy in a bi-layer beam is derived. The strain energy before and after the propagation of the interfacial crack are calculated, lead to the determination of the strain energy release rate. The analytical results of strain energy release rate derived in this investigation are compared with the numerical results obtained from finite element method. The effects of material properties and thickness between the adjacent
layers of interfacial crack are examined through the parametric study.
Conceptual Design, Thrust Test, and Finite Element Analysis of a Tip-Jet Rotor Using a Small Turbo-Jet Engine
Authors: Goo Nam Seo , Park Hoon Cheol , Yoon Kwang Joon
Published: March 2009

A general helicopter uses rotary power produced from the installed engine in order to get the directional thrust. In the case of a tip-jet rotor helicopter, the compressed air or the combustion gas passes through a duct system inside rotors and is ejected out of the nozzle at the blade tips to produce torque enough for rotation of the rotor system. The generated torque makes the rotor system rotate, so that it can create the directional thrust. Since the anti-torque does not occur in this tip-jet rotorcraft,
the tail rotor can be removed, which can be very attractive. In this paper, a power system for a reduced-scale tip-jet rotor by using a small turbo-jet engine is designed and tested for feasibility study. The in-plane thrust that the power system can produce is measured and compared with the calculated one. Finally, the finite element analysis of a conceptually designed tip-jet rotor is performed to ensure
structural safety.
Analysis of the Thickness and Position of Linter Steel Layer in Safety Construction
Authors: Liu Hui Peng , Han Qun-Liang , Yan Zhi-Guo , Gao Wen Ming , Li Ying Ming , Niu Hai-Cheng
Published: March 2009

This paper present an analysis of the mechanics characters of a safety structure with steel liner under near blasting load, by the methods of numerical study. Through the ANSYS/LS-DYNA numerical analysis, we get the reasonable thickness and position location of steel. This paper put forward the curve of the steel at different thickness and position in the safety structure, that provide a reference to the designing of the safety structures and other relevant project.
Viscoelastic Effect on the Fracture Toughness of GFRP: Experimental Approach
Authors: Lana Shirley Savet , Homma Hiroomi , Nakazato Kohji
Published: March 2009

The dynamic fracture tests were carried out for a glass fiber reinforced plastic specimen with a crack and dynamic fracture toughness was evaluated by examination of cracking at an initial slit root. Before the crack initiated at the slit root, a whitened damage zone was created surrounding the slit tip. The damage zone consists of micro cracking in the matrix, debonding between a fiber and the matrix, and fracture of the fiber. The comparison of the dynamic fracture toughness and the static fracture toughness value shows that the former is around 12 MPa√m and apparently higher than the later, which is 7 MPa√m. To understand those experimental results and mechanics of the damage zone, a dynamic debonding test was carried out and dynamic bonding strength was estimated as around 70 MPa.
Damage Detection of Surface Crack in Composite Quasi-Isotropic Laminate Using Modal Analysis and Strain Energy Method
Authors: Hu Hui Wen , Wang Bor Tsuen , Lee Cheng Hsin
Published: March 2009

This paper presents a damage detection of surface crack in composite laminate. Carbon/epoxy composite AS4/PEEK was used to fabricate a quasi-isotropic laminate [0/90/±45]2s. Surface crack was created by using laser cutting machine. Modal analysis was performed to obtain the mode shapes of the laminate before and after damage. The mode shapes were then adopted to compute the strain energy, which was used to define a damage index. Consequently, the damage index successfully predicted the location of surface crack in the laminate. Differential quadrature method (DQM) was introduced to calculate the partial differential terms in strain energy formula.
Influence of Ultrasonic Shear Wave on Defect Angles of Stacking Using CFRP Composite Laminates
Authors: Park Je Woong , Kim Sun Kyu , Kim Young Nam , Yang In Young , Hsu David K. , Im Kwang Hee
Published: March 2009

Because the layup of composite laminates influences there properties, the strength of composites depends on layup sequence of CFRP laminates. It is very important to detect ply error before the laminate is cured for both manual procedure and fiber placement procedure. An ultrasonic technique would be very beneficial, which could be used to test the part after and before curing laminates and requires less time than the optical test. Scanners were set out for different measurement modalities for acquiring ultrasonic signals as a function of in-plane azimuthal angle. The first motorized scanner was utilized for making transmission measurements using a pair of normal-incidence shear wave transducers. A scanner was built for the acousto-ultrasonic configuration using contact transducers. And a ply-by-ply vector decomposition model has been utilized for evaluating layup errors in composite laminates fabricated from unidirectional plies. We have compared the test results with model data. It is found that high probability shows between experimentations and the decomposition model in characterizing cured and uncured laminates with
defect angles.
The Effect Orthosilicic Acid on Collagen Type I, Alkaline Phosphatase and Osteocalcin mRNA Expression in Human Bone-Derived Osteoblasts In Vitro
Authors: Arumugam Meera Q. , Ireland D.C. , Brooks Roger A. , Rushton Neil , Bonfield William
Published: March 2009

The object of this study was to investigate the effect of the concentration of orthosilicic acid (0, 0.5, 1, 5 and 10µM) on gene expression in human osteoblast cells isolated from trabecular bone. This was measured using reverse transcriptase-polymerase chain reaction (RT-PCR) to quantify messenger RNA (mRNA) levels for collagen type I, alkaline phosphatase and osteocalcin.
Results showed that while collagen type I mRNA expression was increased by the addition of up to 10µM orthosilicic acid, ALP message was suppressed over time and osteocalcin levels were decreased.
Influence of Physico-Chemical Properties, Macro- and Microstructure on Osteoinductive Potential of Calcium-Phosphate Ceramics
Authors: Habibovic Pamela , Sees T.M. , van Blitterswijk Clemens A. , de Groot K.
Published: March 2009

Osteoinduction by biomaterials that initially do not contain bone morphogenetic proteins and other growth factors has been shown to be a real phenomenon by many investigators in the past two decades. Although it is well-known that a material needs to meet very specific requirements in terms of physico-chemical and structural properties in order to be osteoinductive, the underlying
mechanism of osteoinduction is not fully unraveled yet. In the present study we investigated parameters which are of importance for the osteoinductive potential of biomaterials by comparing four biphasic calcium-phosphate and a carbonated apatite ceramic. The results showed that the presence of micropores, by which the specific surface area of a material is increased, is essential for the material’s osteoinductivity. However, if the surface area is too high, or material is too resorbable because of its chemical composition, the implant might degrade and lose its shape. In that case, ectopic bone formation does not occur, as a relatively stable surface is needed to facilitate new bone growth.
Fluoridated Ca-Deficient Apatite Formed Via Octacalcium Phosphate Enhances Bone Regeneration
Authors: Kamakura Shinji , Kumagai Takashi , Honda Yoshitomo , Anada Takahisa , Sasaki Keiichi , Shimauchi Hidetoshi , Suzuki Osamu
Published: March 2009

It has been shown that fluoride ions enhance OCP hydrolysis into Ca-deficient apatite and that fluoridation in hydroxyapatite (HA) affects osteoblast activity. The present study was designed to investigate whether fluoridated Ca-deficient apatite (F-HA) formed via OCP enhances bone regeneration. F-HA was obtained through hydrolysis of the OCP in a solution containing 2 ppm fluoride at 37 °C and pH 7.4. A standardized critical-sized defect was made in the rat calvarium, and granules of F-HA were implanted into the defect. Five rats from each group were fixed through four to twelve weeks after implantation. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) confirmed that F-HA corresponded well to apatite structure. In week four, new bone matrix was formed around F-HA. In week twelve of F-HA group, newly formed bone matrix was more abundant, whereas the implanted F-HA was unresorbed and still remained. A statistical analysis in week twelve showed that the newly formed bone in the defect with F-HA was higher than that with untreated group. The fact that new bone was directly formed on F-HA implant suggests F-HA formed via OCP could be used as a bone substitute material.
Revolutionary Treatment of Arthrosis - The Core Drainage Method-
Authors: Shinjo Kiyoshi
Published: March 2009

I have been able to recognize a new pathogenesis of arthrosis. According to this pathogenesis, I have developed a new treatment to drain the joint fluid from the lesional bone marrow. This new treatment is referred
to as “Core Drainage.” The benefits of my “Core Drainage” method were effective for late stage arthrosis and resulted in almost immediate pain relief. This is a minimally invasive procedure that does not require bed rest
post-operatively. Patients are able to bear weight immediately. Core Drainage can prevent progression of arthrosis and can even cure arthrosis at an early stage. With this technique, degenerated and worn joint cartilage was regenerated, and joint effusion and contracture were almost eliminated. The Core Drainage method greatly
enhances the patient’s quality of life.
Nuclear Bone Scintigraphy (NBS): A Valuable Tool Depicting Osseointegration at the Sites of Dental Grafts
Authors: Oktar Faik N. , Turoglu H.T. , Yenici F. Uzum , Altıntaş S.
Published: March 2009

Hydroxyapatite (HA) implants were used as grafting materials to fill some of the root resections in three patients. Two of the patients had previous root resections without implant insertion. Being implanted to the resection sites, the porous structure of HA serves as a framework for vascular and soft tissue ingrowth. Previous reports on the utilization of three phase nuclear bone scintigraphy (NBS) to evaluate the degree of fibrovascular ingrowth into HA dental implants after
surgery are scarce. Three cases are described in which bone scintigraphy was performed at 6 months after implant insertion. The images revealed technetium-99m methylenediphosphonate (99mTc-MDP) uptake at dental implant sites consistent with vascularization and osteoconduction. The current results strongly indicate that osseointegration is complete. This study demonstrates that
NBS is a valuable test in the follow up of osseointegration rate at implantation sites and HA is found to be a good biomaterial for grafting purposes showing high osseointegration rates.
Microstructure–Property Relationships in Human Adult and Baby Canine Teeth
Authors: Low It Meng , Duraman N. , Davies Ian J.
Published: March 2009

Structure-property relationships in baby and adult teeth have been characterised using grazing-incidence synchrotron radiation diffraction and Vickers indentation. Similarities and differences between both types of teeth have been highlighted and discussed. Depth profiling results indicated the existence of contrasting but distinct gradual changes in crystal disorder, phase abundance, crystallite size and hardness within the baby and adult canine enamel, thus confirming
the graded nature of human teeth. When compared to the adult tooth, the baby enamel is softer, more prone to fracture, but has larger hydroxyapatite grains.
Fabrication of Bioactive Glass-Ceramics by Selective Laser Sintering
Authors: Goodridge Ruth D. , Ohtsuki Chikara , Kamitakahara Masanobu , Wood David J. , Dalgarno Kenny W.
Published: March 2009

The feasibility of processing glass-ceramics using the layer manufacturing technique, selective laser sintering (SLS), to produce parts with suitable biological and mechanical properties for use in bone replacement applications, has been investigated. Glass-ceramics derived from glasses based on several different systems have been considered. Initial experiments using an apatite-mullite glass-ceramic (4.5SiO2⋅3Al203⋅1.6P2O5⋅3CaO⋅2CaF2) demonstrated the ability to process glass-ceramic materials using this technique, creating parts with a strength similar to that of cancellous bone, and a porous structure that was shown in vivo to be suitable for the ingrowth of bone. Concerns over the inability of the apatite-mullite material to form an apatite layer on its surface when soaked in a simulated body fluid (SBF) has led to the development of Al2O3-free glasses based on the systems (50-x)CaO⋅45SiO2⋅5P2O5⋅xCaF2 and (48-x)CaO⋅45SiO2⋅5P2O5⋅2CaF2⋅xNa2O. These materials have demonstrated good in vitro bioactivity, and therefore have good potential as candidates for processing by an indirect SLS method for the production of custom-made bone implants.
Morphological and Dimensional Characteristics of Bone Mineral Crystals
Authors: Bertazzo S. , Bertran Celso A.
Published: March 2009

In this work, Scanning Electron Microscopy (SEM) has been used to determine the size and morphology of bone mineral crystals obtained from hydrazine-deproteinated parietal bone and femur of Wistar rats aged 15 days, 1 month and 1 year. Apart from the Scanning Electron Microscopy study, crystal size was also determined by X-ray diffractometry, using the Debye- Scherrer equation. Analyzing the results obtained and those reported in the literature for isolated crystals, it is possible to evaluate the influence of age and type of bone on the nanostructure of bone mineral and also propose the existence of a fundamental morphological unit that repeats itself in bone mineral formation.
Effect of Electrical Polarization on the Behavior of Bioactive Glass Containing MgO and B2O3 in SBF
Authors: Amaoka Emiko , Vedel Erik , Nakamura Satoshi , Moriyoshi Yusuke , Salonen Jukka I. , Yamashita Kimihiro
Published: March 2009

We investigated the electrical polarizability of MgO and B2O3 containing bioactive glass (MBG). The MBG material with good manufacturing properties but low bioactivity was electrically polarized at a high dc field. The electrical polarizability of MBG was evaluated by thermally stimulated depolarization current (TSDC) measurements and immersion in simulated body fluid (SBF). The early precipitation of calcium phosphate on the negatively charged surface of the
treated MBG demonstrated the increased bioactivity of the material and confirmed its polarizability. It is suggested that the electrical interactions between the polarized MBG and ions in SBF promoted the formation of the calcium phosphate precipitation. Accordingly, the increased bioactivity of the MBG in SBF is suggested to demonstrate the conversion of MBG into electrovector ceramics by the
polarization treatment.
Synthetic Calcium Phosphate Nanoparticles Mimetic of Bone Mineral: Similarities in Composition and Morphology
Authors: Bertazzo S. , Bertran Celso A. , Kawachi E.Y.
Published: March 2009

In this work, calcium phosphate particles were obtained from systems composed of
Renex-100, hexanol, cyclohexane and Ca2+, PO4
3- and OH- aqueous solutions. Particles of chemical
composition, crystalline structure, morphology and size similar to those of bone mineral were obtained by varying the composition of the components of the system. For comparison, the mineral phase of bone was obtained from parietal bone and femur of 15-day, 1-month and 1-year-old Wistar rats. Synthetic calcium phosphates and bone samples were analyzed by XRD, ICP/OES and electronic
microscopy. The results show that, by controlling the composition of the surfactant system, it is possible to obtain particles of different morphologies and sizes, which are more similar to the particles that compose bone mineral. This similarity might indicate that the body makes use of systems to synthesize bone mineral. These systems might present properties similar to those of the systems studied in this work.
Biocompatibility and Osteoconductivity of Hydroxyapatite/Polysaccharide Nanocomposite Microparticles
Authors: Omi H. , Itoh Soichiro , Ikoma Toshiyuki , Asou Y. , Nishikawa S. , Tanaka M. , Shinomiya Kenichi , Toh Satoshi
Published: March 2009

Hydroxyapatite/hyaluronic acid (HAp/HyA) and hydroxyapatite/chondroitin sulfate (HAp/ChS) microparticles, which show the high adsorption ability of proteins, high biocompatibility and osteoconductivity, are potential scaffolds for a time-controlled BMP release. The present study evaluated the biocompatibility and osteoconductivity of the composites after injection into bone defect. Drilled bone holes were made at tibia and femur of Japanese white rabbits, and HAp/HyA or HAp/ChS was implanted into each bone hole using an injection syringe. After 2 and 4 weeks of implantation, rabbits were sacrificed and histological observations were conducted with HE, TRAP, and ALP staining. Histological observations revealed that HAp/ChS has superior biocompatibility compared with HAp/HyA, and 20% HAp/ChS promotes bone formation as well as osteoblast activities compared with lower ratios of HAp/ChS.
Preparation of Hydroxyapatite Ceramics by Hydrothermal Hot-Pressing Technique
Authors: Yanagisawa Kazumichi , Zhu Kongjun , Fujino Takahiro , Onda Ayumu , Kajiyoshi Koji , Ioku Koji
Published: March 2009

The hydrothermal hot-pressing (HHP) technique was used to prepare hydroxyapatite (HAp) ceramics from a HAp powder with low crystallinity, and the effects of processing factors such as temperature, loading pressure and reaction time on densification were investigated. The crystallinity of HAp was increased by the HHP treatments. With the increase in reaction temperature, loading pressure and reaction time, the density and Vickers hardness of the compacts
increased. The HAp compact with high relative density of 83% and high Vickers hardness of 2.9 GPa was successfully prepared by the HHP treatment at 200°C for 3 h under loading pressure of 60 MPa.
Neutron Characterisation of Hydroxyapatite Bioceramics
Authors: Kealley Catherine , Elcombe M. , van Riessen A. , Ben-Nissan Besim
Published: March 2009

This paper reports neutron diffraction data and its analysis that characterise a biocompatible hydroxyapatite composite material. The neutron data has elucidated the crystal structure, and enabled the positions of the hydrogen atoms to be determined. The data also shows the improvement of crystallinity during the heat treatment process. An extension of the work involved looking at a hydroxyapatite – carbon nanotube composite material, and neutron diffraction has shown that the retention of the carbon nanotubes in the composite material has been successful. The nanotubes have had no affect on the hydroxyapatite structure.
Preparation and Characterization of Hydroxyapatite Microspheres with Hollow Core and Mesoporous Shell
Authors: Peng Qian , Ming L. , Jiang C.X. , Feng Bo , Qu Shao Xing , Weng Jie
Published: March 2009

Hollow hydroxyapatite microspheres (H-HAMs) with controlled characteristic
mesoporous structure on the shell were successfully fabricated by using core template technology and sol-gel process. The fabrication of H-HAMs mainly included three distinct steps: the preparation of core template spheres of chitin by emulsifying chitin solution in oil, the formation of core-shell composite spheres of chitin-HA/chitin after a layer of chitin/HA solution coated on the surface of chitin core templates by means of a gelling process of chitin solution with the help of water in the cores, and the harvest of H-HAMs through a special sintering procedure to remove
chitin. The size and shape of H-HAMs were chiefly determined by the size and morphology of core templates. The thickness of shells was easily controlled by altering water content of the starting template particles, and the characteristic mesoporous structure on the shell was related to the proportion of chitin in the chitin/HA composite solution and the sintering temperature. H-HAMs
with characteristic mesoporous architecture on the shell have many potential applications such as used as a carrier for sustained release of drugs in the therapy of hard tissue system.