bluuebunny/crossref_metadata_2025 huggingface dataset:
Pendulum Test and Parameters for Quantitative Evaluation of Spasticity
Authors: Lim Hyun Kyoon , Cho Kang Hee , Kim Bong Ok , Lee Young Shin
Published: March 2009

In this study, we assessed spasticity objectively and quantitatively using the pendulum
foot drop test. Twenty-eight patients with spasticity and ten healthy subjects participated in the
study. A newly designed table for the motion analysis system using infrared cameras and a foot
release mechanism were used. Electromyograph (EMG) was recorded from eight muscles of the
lower limb during a foot drop maneuver. The study investigators suggest ‘modified relaxation
index’ as a good representative parameter for describing spasticity. This parameter is based on
quantitative measurement rather than investigator discretion, as in the modified Ashworth scale
(MAS).
The Effect of 3D Construction Culture of Human Chondrocytes Using Alginate Sponge
Authors: Lee Jin Sang , Kim Byung , Kim Min Soo , Lee Seung Jae , Kim Sung Won , Cho Dong Woo , Kim Joo Sung , Lim Geun Bae
Published: March 2009

In this study, we investigated the effect of the use of alginate sponge as a chondrocyte-3D
scaffold for the construction of a cartilage graft. Alginate sponge was made by 5% alginic acid
which was crosslinked by CaCl2. Chondrocytes were obtained from a nasal septum after the
operation and cultured in 3D alginate sponge. For analysis of cell differentiation, we have checked
aggrecan, collagen type I and II using RT-PCR and performed the histological and scanning
electron microscopy analysis. Our experiments showed that alginate sponge of 5% promoted
sufficient chondrocyte proliferation and differentiation, resulting in the formation of a specific
cartilage matrix. The sponge presents new perspectives with respect to in vitro production of
"artificial" cartilage. We conclude that the alginate sponges have potential as a scaffold for cartilage
tissue engineering.
Diffusion Tensor Imaging in Patients with Thalamic Hemorrhage: Correlations between Diffusion Anisotropy and Motor Recovery
Authors: Tae Ki Sik , Song Sung Jae , Han Bong Soo , Lee So Young , Park Gi Young , Sohn Chul Ho , Jeon Hye Seon , Choi Mun Suk , Kim Young Ho
Published: March 2009

Diffusion tensor imaging (DTI) provides quantitative information in the magnetic
resonance imaging on the diffusion anisotropy about the integrity of white matter tracts. The aim of
this study was to measure diffusion anisotropy and to correlate with upper-limb motor recovery in
four chronic hemiparetic patients with thalamic hemorrhage. Fractional anisotropy (FA) was
measured in the posterior limb of internal capsules (IC) in the affected side and in the corresponding
contralateral normal side before and after 6 week motor training. The correlation between motor
recovery of the affected hand and the ratio of FAs of the affected side and the contralateral normal
side were investigated. Both FA ratio and motor function significantly increased after the training.
A significant correlation was found between motor recovery and FA in the posterior limb of IC. The
degree of impairment in diffusion anisotropy of hemiparetic patients might be helpful in prognosis
of the motor function.
Impact Path Analysis of Human Body with Three Typical Shooting Postures
Authors: Choi Young Jin , Lee Young Shin , Lee Se Hoon , Chae Je Wook , Choi Eui Jung , Hong Suk Kyun
Published: March 2009

The hit rate is affected by the shooting impact of the human-rifle system. The impact
response of the human-rifle system is determined mainly by the geometrical parameters and contact
boundary conditions. In this study, the height and weight of the considered human model are 170
cm and 60 kg, as these parameters mirror 50 per cent of Korean males in their twenties. The rifle
model is applied on the K-2. The impact path analysis of three typical shooting postures: the
standing, kneeling and prone shooting postures is performed with experimental impulse-time
history during a shooting test. The biomechanical response such as impact transfer path, force
history and displacement history are investigated.
A Computer Simulation Study of Fusion Surgery and Artificial Disc Replacement on the Human Cervical Spine
Authors: Ahn Hyung Soo , Park Il Hyung , DiAngelo Denis
Published: March 2009

The biomechanical changes brought on by spine fusion and the artificial disc designs to
restore physiologic motion were studied by using a cervical spine computer model. Fusion
increased the motion compensation at the adjacent segment during flexion and extension. The
global rotational stiffness and segmental disc forces were also increased after fusion. Among the
three prosthetic disc designs, the PDD-III (5-DOF spherical joint in plane parallel with the C5-C6
disc level) maintained the normal motion and minimized load build up of adjacent segment.
Dynamic ESPI System for Spatio-Temporal Strain Analysis of a Deforming Solid Object
Authors: Shiraishi Tomohisa , Toyooka Satoru , Kadono Hirofumi , Saito Takayuki , Ping Sun
Published: March 2009

In Dynamic Electronic Speckle Pattern Interferometry (DESPI), deformation analysis
could be done for successively acquired frame data of interfering speckle patterns with no
additional frames like phase shifting speckle patterns. Our final goal is to obtain a temporally
varying process of two-dimensional strain field. Two normal strains and shearing strain are
derived by numerical derivatives of two components of in-plane deformation. Analyzed results of
tensile experiments of an Al-alloy sample will be shown. In the experiments, propagation of a
strain localization band accompanied by serration of a stress curve was clearly observed
quantitatively analyzed.
Life Prediction of Thermo-Mechanical Fatigue for Nickel Based Superalloy IN738LC
Authors: Hyun Jung Seob , Song Gee Wook , Lee Young Shin
Published: March 2009

An experimental program has been carried out to address the thermo-mechanical fatigue
life of the uncoated IN738LC nickel-base superalloy. High temperature isothermal Fatigue and
out-of-phase(OP), in-phase(IP) TMF experiments in strain control were performed on superalloy
materials. Temperature interval of 450-850 was applied to thermo-mechanical fatigue tests. The
stress-strain response and the life cycle of the material were measured during the test. The plastic
strain energy based life pediction models were applied to the stress-strain history effect on the
thermo-mechanical fatigue lives.
Random Fatigue Analysis of Automotive Bevel Gear
Authors: Kim Duck Hoi , Kim Jae Hoon , Kim Gi Gwang , Lee Young Shin
Published: March 2009

The most common mode of the gear failure is tooth breakage, which is usually produced
by bending fatigue failure. It is important to manufacture the gears which can withstand the applied
stresses in view of safety and economic requirements. In this study, fatigue test and analysis were
performed to evaluate the bending fatigue strength of an automotive bevel gear. Test fixtures of the
double tooth concept were considered to obtain reliable fatigue test results. Fatigue life of
automotive bevel gear was evaluated by Weibull analysis. To compare the test results and to verify
the fatigue analysis procedures, fatigue analyses were carried out. The results of fatigue analysis
show that fatigue life and crack initiation sites were well agreed with test results. The random
loading of bevel gear under the real driving conditions was defined here, and then the fatigue
analysis under random loading was also performed.
Development of a New Laser Conditioning Method for Ultra-Fine Grit Diamond Wheels
Authors: Kunieda Yasuhiro , Matsuura Hiroshi , Kodama Sohei , Yoshihara Nobuhito , Yan Ji Wang , Kuriyagawa Tsunemoto
Published: March 2009

This paper reports a new laser conditioning method for micro-wheels with ultra-fine grit
diamond, which are used for the micro grinding of micro-aspherical optics. Resinoid-bonded
micro-wheels with ultra-fine grit diamonds are used for micro grinding. Such small wheels have the
problem of poor ground surface roughness due to their few effective cutting edges and low peripheral
speeds. In the present work, new truing and dressing methods are proposed to produce many effective
cutting edges. The new method uses the third harmonic of a Nd:YAG laser, which is suitable for
processing resinoid bond material. It was found that a SD1500B wheel treated using the new method
had a higher cutting edge density than one treated using a conventional method, the cup truer method.
A good surface roughness was obtained using the new method.
A Study of Basic Characteristics of Polishing Using Particle-Type Electro-Rheological Fluid
Authors: Tanaka Takeshi
Published: March 2009

In this study, we proposed ER fluid-aided polisher (ERAP) using one-sided, patterned
electrodes. The characteristics of ER fluid and ER fluid containing abrasive grit were investigated.
The polishing performances of ER fluid containing abrasive grit were verified using an ERAP. The
following conclusions were obtained.
Thick clusters formed between both electrodes with increased voltage. Abrasive grit was
condensed on the thick clusters of ER fluid-particles that formed around the electrodes with further
increases in voltage. The ER effect is a hardening of ER fluid under loading by an electric field. The
ER effect of ER fluid containing abrasive grit decreased because the grit clusters bound weakly to
each other. The ER effect decreased with a decrease of grit size. The surface roughness showed
little change when a Shower curtain (a nylon cloth) was used for a pad. An electric field was
generated around the cutting zone when a Toraysee (a washable lens cloth) was used as a pad. This
leads to large efficiency and high precision in polishing. The surface roughness decreased with
increased voltage up to 1.0kV/mm, because the abrasive grit was tightly fixed by the ER effect. A
minimum surface roughness was attained at approximately 1.0 kV/mm when using WA and SD
grits. The surface roughness increased due to a hardening of the ER fluid, causing deep scratching
of the workpiece at 2.0kV/mm.
Roundness Modeling Using Fractal Interpolation
Authors: Yoon Moon Chul , Chin Do Hun
Published: March 2009

There are many modelling methods using theoretical and experimental data. Recently,
fractal interpolation methods have been widely used to estimate and analyse various data. Due to the
chaotic nature of dynamic roundness profile data in roundness, some desirable method must be used
for the analysis of data which is natural to sequential data. Fractal analysis used in this paper is within
the scope of the fractal interpolation and fractal dimension. Also, two methods for computing the
fractal dimension have been introduced, which can calculate the fractal dimension of typical dynamic
roundness profile data according to the number of data points in which the fixed data are generally
lower than 120 data points. This fractal analysis shows a possible prediction and analysis of roundness
profile that has some different roundness profile in round shape operation such as cylindrical grinding,
turning, drilling and boring.
Development of Small Radius Ball End Mill for Deep Precision Machining - Feasibility of Highly Accurate Deep Precision Machining with Less Vibration -
Authors: Akamatsu Takeshi , Kitajima Koichi , Matsumoto Y. , Kiriyama T.
Published: March 2009

The machining of metal dies involves a variety of processes that include grinding, polishing and
electrical discharge machining in addition to various cutting processes such as turning, boring, and milling.
The precise machining of complex dies, particularly in deep machining, has largely been done by
electrical discharge machining in the past, because the use of end mills and other cutting tools for such
work has been difficult. In recent years, however, problems such as low machining efficiency and the
creation of an affected layer have made the use of end mill cutting tools the general approach to this task.
In the research reported here, our objective was to establish guidelines for the optimum design of small
radius ball end mills for the deep machining of dies by systematic investigation of the cutting tool
characteristics, which is to say the rotational behavior, cutting resistance, actual rate of depth of cut and
machining accuracy of small radius ball end mills.
Here, the guidelines obtained for ultra-deep, highly-accurate machining that is applicable to machining
programs and is based on quantitative results for amounts of tool wear and tool deflection that
obtained using the optimum tool shape reported earlier are presented.
Direct Fabrication of Bulk Nanostructured Ceramic from Nano-Al2O3 Powders by Selective Laser Sintering
Authors: Shen Li Da , Huang Y.H. , Tian Zong Jun , Hua Guo Ran
Published: March 2009

Nanostructured ceramic bulk materials were achieved from nano-Al2O3 ceramic powders
via direct selective laser sintering (SLS). SLS as a non-traditional machining technology of Rapid
Prototyping was introduced and compared with other ceramic forming technologies. Scanning
electron microscopy (SEM) and X-ray diffraction (XRD) were applied to analyze the microstructure
of the ceramic bulk materials. These results demonstrated that the nano-Al2O3 ceramic powders can
be sintered into bulk materials maintained nanostructure with some technological parameters. It was
found that the nanostructured ceramic bulk exhibited unique microstructure and was free formed
rapidly by this sintering technology.
A New Four-Point Bending System to Supply Cultured Adhensive Cells In Vitro with Cyclic Uniaxial Strain
Authors: Li Juan , Zhao Zhi He , Chen Guo Ping , Tang Hai , Li Zhi Hua , Zeng Jun , Luo Song Jiao , Zheng Yi , Zhou Zheng
Published: March 2009

We have designed a new four-point bending system by combination of integrate circuit and
beam-deflection theory, and conducted a series of experiments concerning cell morphology and
proliferation. The system was proved to be able to supply the cultured anchorage-dependent cells with
cyclic uniaxial stretching strain and compressive stress easily, precisely and effectively.
In-Vitro Wear of Different Ceramic Couplings
Authors: Oberbach Thomas , Begand Sabine , Glien Wilfried
Published: March 2009

Alumina and zirconia have been used in joint prostheses for decades. With mixtures of both materials (ZTA and ATZ) mechanical strength can be increased. The wear behaviour was investigated using standard and microseparation conditions. Both materials ZTA and ATZ showed similar or better wear resistance compared to alumina.
Stability of Regenerated Bone by Octacalcium Phosphate (OCP) Combined with Collagen
Authors: Kamakura Shinji , Sasaki Kazuo , Honda Yoshitomo , Anada Takahisa , Kawai Tadashi , Matsui Keiko , Echigo Seishi , Suzuki Osamu
Published: March 2009

Our previous study showed that synthetic octacalcium phosphate (OCP) enhanced bone
regeneration more than hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP). Recently, we have
engineered a composite of synthetic OCP and collagen (OCP/Collagen), which improved the
handling performance and synergistically enhanced bone regeneration up to eight weeks after
implantation. The present study investigated whether the regenerated bone by OCP/Collagen could
be stable for long period. OCP/Collagen sponge was prepared from pepsin-digested atelocollagen
isolated from the porcine dermis and OCP granules. A standardized critical-sized defect was made in
the rat calvarium, and an OCP/Collagen was implanted into the defect. Five rats were fixed at
twenty-four weeks after implantation and examined radiographically and histologically.
Radiographic examination showed that radiopaque figure was occupied throughout the defect,
whereas OCP/Collagen itself was no radiopacity before implantation. Histological examination
showed that newly formed bone was observed throughout the defect in OCP/Collagen. The implanted
OCP/Collagen tended to be resorbed and was replaced by newly formed bone. The regenerated bone
was stable and matured. The present study indicated that bone regeneration by the implantation of
OCP/Collagen was stable for long-term periods. Application of OCP/Collagen without both cell
transplantation and exogenous osteogenic cytokines would result in cost-effective bone regenerative
therapy in the future.
Biocompatibility of Nano-TiO2/HA Bioceramic Coating for Nerve Regeneration around Dental Implants
Authors: Yuan Quan , He Gang , Tan Zhen , Gong Ping , Li Xiao Yu , Chen Zhi Qing , Ban Yu , Tang Hua , Wang Fang Fang , Man Yi , Wei Na , Zhu Z.L.
Published: March 2009

Sensory perception thresholds of implants were much higher than those of natural teeth.
The purpose of this study was to evaluate the biocompatibility of TiO2/HA-biocoated dental
implants for nerve regeneration using cultured Schwann cells. The nano-TiO2/HA composite
bioceramic coating was developed on the surfaces of commercially pure titanium discs by sol-gel
route, and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).
Using smooth titanium discs as a control, Schwann cell responses to the coating were evaluated by
SEM, MTT assay, total protein content and leakage of cytosolic lactate dehydrogenase (LDH)
activity. In addition, the amount of brain-derived neurotrophic factor (BDNF) secreted by Schwann
cells was measured by Enzyme-Linked Immunosorbent Assay (ELISA). It was observed that the
coating had fine crystallites and homogeneous micropores in the diameter of 5-10 um. The cell
morphology, proliferation and function were unaffected. The results indicate that the TiO2/HA
bioceramic coating developed on the surface of pure titanium by sol-gel route had good
biocompatibility with Schwann cells for nerve regeneration around dental implants.
Occlusion Effect of Dentinal Tubules of the Dentifrice Containing Sodium Metasilicate
Authors: Lee Su Young , Jang S.O. , Kim Hae Sun , Choi Jai Hyuk , Kwon H.K. , Kim B.I.
Published: March 2009

Exposed dentine with patent tubules allows the movement of tubule fluid leading to
dentine sensitivity. Occlusion of patent dentinal tubules effectively reduces the state of dentine
hypersensitivity. Strontium chloride (SrCl2) has been well known as a component of desensitizing
dentifrice. Recently, new dentifrice containing sodium metasilicate was on the market for
desensitizing dentifrice. The aim of this in vitro study was to compare the occlusion effect of
dentinal tubule between the sodium metasilicate and the existing desensitizing dentifrices. Sixtyfour
human dentine specimens were embedded into a Teflon mold and were grinded with the use of
silicone carbide papers to expose the surface of dentin. The dentin surface was etched with 37%
phosphoric acid for 60 seconds and was treated with ultrasonic washing for 1 hour. The dentifrices
used in the study are classified into four groups: G1-dentifrice containing Sodium metasilicate, G2-
dentifrice containing Strontium chloride, G3-dentifrice containing Hydroxyapatite and G4-BSI
reference dentifrice (control group). Toothpaste slurries were prepared as 20 gram of toothpaste in
80 ml of distilled water. Thirty-two specimens were brushed with the toothpaste slurries using V8
Cross Brushing Machine. Tooth-brushing was performed 5,000 times using a back-and–forth stroke.
The pictures of the sizes of dentinal tubules were taken by scanning electron microscopy (×3000)
and changes of tubule sizes were analyzed by digital analysis. The results showed that the
difference of tubule size in descending order: G1-3.30±1.80, G2-2.82±1.73, G3-1.49±1.14, G4-
1.04±0.94. The dentifrice containing Sodium metasilicate (22.5%) showed the highest dentinal
tubule occlusion. Moreover, the dentifrice containing Sodium metasilicate statistically significantly
increased occlusion of dentinal tubule as compared to BSI reference dentifrice (p<0.05). Thus, new
desensitizing dentifrice containing sodium metasilicate was more effective than existing
desensitizing dentifrice on occlusion of dentin tubules.
Preparation of Apatite-Containing Calcium Phosphate Glass-Ceramics
Authors: Kasuga Toshihiro , Ueno Emiko , Obata Akiko
Published: March 2009

A new type of glass-ceramic for novel dental fillers, which require excellent chemical
durability, was investigated. A 40CaO-5CaF2-25TiO2-30P2O5 (in mol%) glass-ceramic was newly
suggested. The glass-ceramic was prepared by a conventional two-step heating method. The
resulting glass-ceramic included Nasicontype-CaTi4(PO4)6, titanium phosphates, such as
(TiO)2P2O7 and Ti(PO3)3, and TiO2 (anatase) with apatite crystal, which was induced by
incorporation of fluorine. In the glass-ceramic, dissolution by acid-treatment was strictly controlled.
The excellent chemical durability of the glass-ceramic was suggested to originate from increase in
the amount of the crystalline phases and a high content of titanium constituent in the residual glassy
phase.
Factors Controlling Antibacterial Properties of Bioactive Glasses
Authors: Zhang Di , Munukka Eveliina , Hupa Leena , Ylänen Heimo O. , Viljanen Matti K. , Hupa Mikko
Published: March 2009

Factors controlling the antibacterial ability of three bioactive glasses were studied by
comparing the changes in the SBF during immersion of the glasses with their response to four
microorganisms. After immersion of 100 mg/ml fine powder (<45μm) of the glasses in the SBF for
1, 2, 4, 8, 16, 27 and 48 hours, the immersion solutions were filtered and the pH in the bulk solution
was measured. Ionic concentrations of Na, K, Ca, Mg, P and Si ions in the immersion solutions
were determined by ICP-OES. The antibacterial activity of the glasses showed good correlation
with the changes of the pH values in the SBF solutions. No correlation was found between the ionic
concentration and the antibacterial ability of the three glasses against the four tested
microorganisms. The results suggest that, the antimicrobial effect of the glass powder against the
microorganisms tested is mostly dependent on the increase of the pH in the solution to values
detrimental for the bacteria growth.
Preparation and Characterization of Nano Hydroxyapatite
Authors: Li B. , Wang Xin Long , Guo B. , Xiao Yu Mei , Fan Hong Song , Zhang Xing Dong
Published: March 2009

The aim of this study is to prepare nano hydroxyapatite powder. Hydroxyapatite powder was prepared via co-precipitated method with the addition of citric acid at pH 9-11 in ambient environment. The precipitates were aged for 24hs, and then milled into powder after washed and dried. The particle morphology and particle size of as prepared HA powders were characterized. The results showed that hydroxyapatite powder with width of 10-30nm and length of 30-100nm was prepared by wet co-precipitation.
Biomimetic Organic-Inorganic Nanocomposite Coatings for Titanium Implants: I. Preparation, Physicochemical and Mechanical Characterization
Authors: Dutour Sikirić M. , Gergely Csilla , Cuisinier F. , Füredi-Milhofer Helga
Published: March 2009

In the production of artificial bone and tooth implants, coating of the surfaces of hard, but
bioinert materials (metals, polymers) with calcium phosphate crystals has been used to improve
bioactivity and facilitate osteointegration. Recently low temperature methods, involving
precipitation from aqueous solutions (biomimetic precipitation) including coprecipitation of specific
organic macromolecules (growth hormones, enzymes, proteins) have been developed. In this paper
an alternative approach is presented, which consists in first laying down a matrix consisting of
polyelectrolyte multilayers (PE MLs) alternating with layers of amorphous calcium phosphate
(ACP) particles and subsequently growing calcium phosphate crystals upon/within the multilayers.
This attractive approach leads to the formation of a new class of true organic-inorganic
nanocomposite coatings. In a previous communication we have shown preliminary results, which
point to the feasibility of this approach [1]. Here we describe in detail the design, synthesis and
characteristics of the thus obtained nanocomposite coatings.
Influence of Collagen Status on Microstructures of Porous Collagen/TCP Composites
Authors: Zou Chao , Weng Wen Jian , Deng Xu Liang , Cheng Kui , Du Pi Yi , Shen Ge , Han Gao Rong
Published: March 2009

Two starting collagens, sponge and floc collagen, were used to prepare
collagen/tricalcium phosphate (TCP) composites. The resulting composites were porous and had
200μm pore size. However, there was a difference in the microstructure of the pore walls for the
composites derived from the two collagens, the pore walls in sponge collagen/TCP composite
were still porous and had 200 nm micropores size, TCP particles were trapped in collagen
matrices. While floc collagen/TCP composite had smooth and dense walls in which TCP particles
were embedded. The difference could be attributed to the starting collagen with different status.
Sponge collagen has a soft structure, which easily becomes disassembled fibrils during alkali
treatment, the disassembled fibrils are integrated again to form a dense morphology for pore walls
after freeze-drying. While floc collagen has already a low disassembly degree, the alkali treatment
could not be able to separate the fibrils, this remains as micropores in pore walls after
freeze-drying. Both porous composites are significant in bone tissue engineering or regeneration.
MTT test results showed the two composites had good cytocompatibility, and sponge
collagen/TCP composite was somewhat better than floc collagen/TCP composite, which could
result from that micropores derived roughness in pore walls of sponge collagen/TCP composite is
suitable for cell growth.
Preparation and Characteristics of Strontium Containing Bioactive CaSiO3 Ceramics
Authors: Wu Cheng Tie , Zreiqat Hala
Published: March 2009

Strontium(Sr) containing CaSiO3 powders were synthesized using chemical precipitation.
X-Ray Fluorescence (XRF) analysis confirmed the incorporation of Sr in CaSiO3. X-Ray diffraction
(XRD) analysis revealed that the incorporation of Sr into the lattice structure of β-CaSiO3 powders,
does not change its β-phase composition. The lattice dimension of β-CaSiO3 powders increased
with the increase of Sr contents (0-10% Sr). Sr-CaSiO3 ceramic disk were prepared from the
Sr-CaSiO3 poweders by uniaxial pressing at 150 MPa and sintering at 1100°C for 3h. XRD and
Differential Thermal Anaysis (DTA) analysis indicated that there is a correlation betweem Sr
concentration (0-10% Sr) and the phase transition from β-CaSiO3 to α-CaSiO3 with the increase of
Sr contents. This transition was promoted by the decrease in temperature.
Three-Dimensional Characterization of the Microstructure of Bioglass/Polyethylene Composite by X-Ray Microtomography
Authors: Fu Xiao Wei , Huang Jie , Thian E.S. , Best Serena , Bonfield William
Published: March 2009

A Bioglass® reinforced polyethylene (Bioglass®/polyethylene) composite has been prepared, which combines the high bioactivity of Bioglass® and the toughness of polyethylene. The spatial distribution of Bioglass® particles within the composite is important for the performance of composites in-vivo. Recent developments in X-ray microtomography (XμT) have made it possible to visualize internal and microstructural details with different X-ray absorbencies, nondestructively, and to acquire 3D information at high spatial resolution. In this study, the volume fraction and 3D spatial distribution of Bioglass® particles has been acquired quantitatively by XμT. The information obtained provides a foundation for understanding the mechanical and bioactive properties of the Bioglass®/polyethylene composites.
Morphologies of Hydroxyapatite Crystal Deposited on Titanium Surface with Electrochemical Technique
Authors: Ye Wei , Wang Xiao Xiang
Published: March 2009

Homogeneous coatings adhered strongly to titanium substrates were attained by electrochemical method in electrolytes containing Ca2+ and PO4 3- ions with Ca/P ratio being 1.67. SEM observation showed that the HAp crystals prepared with higher concentration electrolyte (4x10-2M Ca2+) are ribbon-like with thickness of nanometer size, a morphology seldom reported previously. In an electrolyte of lower concentration (6x10-4M Ca2+), the HAp crystals formed are rod-like with defined hexagonal cross section and diameter of about 70-80nm. The electrolyte of intermediary concentration (5x10-3M Ca2+) produced plate-like HAp crystals. XRD patterns and IR spectra confirmed that the coatings consist of HAp crystals.
Surface Charge of Hydroxyapatite and Bone Mineral
Authors: Bertran Celso A. , Bertazzo S. , Faria L.P.
Published: March 2009

The surface charge of calcium phosphates in Simulated Body Fluid (SBF) may be one of
the factors associated with the adhesion of cells and proteins, processes that are related with
osteogenesis. For calcium phosphates in SBF, surface charge varies with solution pH due to the
adsorption of positive ions and to the reactions that occur at the solid/biological fluid interface. In
this work, the variation of the density of protons adsorbed and the surface charge as a function of
pH were determined for Hydroxyapatite, CaHPO4, and Bone Mineral.
Immobilization of Collagen on Hydroxyapatite and Its Interation with Cells
Authors: Jung K.H. , Kang Inn Kyu , Kim Sung Min , Ahn Myun Whan , Kim Suk Young
Published: March 2009

The adhesion of bone cells on substrate materials is generally measured by the removal
torque and/or contact area between bone and implants. In this study, collagen was used as a surfacegrafting
material on hydroxyapatite (HA) substrates to enhance the cell adhesion because the
collagen is a major constituent of connective tissues and has been regarded as one of the most
excellent coating materials for bone bonding. First, HA disks (10mmΦ x 1mm) were prepared and
then collagen was immobilbized on the HA surface using an 3-APTES coupling agent to improve
the adhesiveness of cells on HA disk surfaces. NIH 3T3 fibroblasts were seeded on the collagengrafted
and non-grated HA disks and cultured in a Dulbecco’s modified eagle medium containing
10% fetal bovine serum for 3 hrs to evaluate the cell adhesion on the HA samples. The fibroblasts
on the collagen-grafted sample were more spread than those on the non-grafted sample. It is
believed that collagen-grafted HA surface provides suitable sites for cell attaching due to the high
biocompatibility of collagen.
Effect of Mn on Protein Adsorption on Mn-TCP/FHA Coatings
Authors: Cheng Kui
Published: March 2009

The effect of Mn on the protein adsorption of calcium phosphate coatings is investigated in
this work. Mn containing β-tricalcium phosphate (Mn-TCP) is first prepared through a
coprecipitation based methods. Then Mn-TCP is dispersed into the fluoridated hydroxyapatite (FHA)
precursor sol. Mn-TCP/FHA biphasic coatings are prepared with these sols. After cell culture, it is
found the amount of protein adsorbed on the coatings following this rule: Mn-TCP/FHA >
β-TCP/FHA > FHA. That is ascribed to two reasons: a) Ca and PO4 releasing can promote the activity
of cells; b) Mn releasing promotes protein activation even at quite low concentration.
Biocompatibility Improvement of Pure Hydroxyapatite (HA) with Different Porosity
Authors: Hornez Jean Christophe , Chai Feng , Blanchemain N. , Lefèvre A. , Descamps M. , Hildebrand H.F.
Published: March 2009

Calcium phosphate compounds, in particular HA and β-TCP, are the principal synthetic materials used for bone substitutes. To assess the feasibility for further grafting of drug delivery systems, a pure HA was elaborated with specific internal material porosities and then tested on its biological effectiveness. The cell viability tests with L132 cells confirmed the excellent cytocompatibility of HA and the graphite powder. MC3T3-E1 osteoblasts were grown on HA conditioned with culture medium and FCS for 2h. All HA samples produced a higher proliferation and vitality rates than the TCPS controls; the micro-porous HA inducing the highest cell growth near 150%. The macro/meso-porous HA is easily colonized by MC3T3-E1 osteoblasts As to the cell morphology, no significant differences are observed between control cells and those grown on the HA samples. Cytochemical staining of osteoblasts revealed a well developed cytoskeleton with strong stress fibres oriented in the cells in their longitudinal direction. Labelling of the focal adhesion contacts with anti-vinculin showed a less developed adhesion process in the cells on the different HA substrates, which may explain the above mentioned increase of proliferation.
Lamination Process to Obtain Structure with Tailored Residual Stress Distribution
Authors: de Portu Goffredo , Micele Lorenzo
Published: March 2009

In this paper a method to produce laminated ceramic composites containing residual stresses is described. The method consist in superimposing thin layers obtained by tape casting, their worm-pressing and sintering. Detailed information on the process and on the slurry compositions are reported. The reasons why laminated structure can exhibit improved performances are also illustrated. The model on which a multilayer composite, containing residual stresses, can be designed is briefly illustrated. The relationship among the physical, chemical and microstructural properties of the different layers, necessary to stimulate the residual stresses outlined.
Progressive Failure Analysis of Unidirectional-Fabric Laminated Composite Joints under Pin-Loading
Authors: Kweon Jin Hwe , Son Hee Jin , Choi Ji Young , Shin So Young , Choi Jin Ho , Lee Gun Myung
Published: March 2009

A two-dimensional progressive failure analysis is conducted to predict the failure loads
and modes of carbon-epoxy composite joints under pin-loading. An eight-node laminated shell
element is used for the finite element modeling. Post-failure stiffness is evaluated based on the
complete unloading model combined with various failure criteria. The comparison of finite element
and experimental results shows that the finite element analysis based on the combined maximum
stress and Yamada-Sun criteria most accurately predicts the failure loads of the composite
laminated joints.
Ionic Liquid Nafion Nanofiber Mats Composites for High Speed Ionic Polymer Actuators
Authors: Nah C. , Kwak S.K. , Kim N. , Lyu M.Y. , Hwang B.S. , Akle B. , Leo D.J.
Published: March 2009

A new attempt is made for application of the NafionTM nanofiber mat prepared by the
electrospinning process to solve the main disadvantage of slow response speed of ionomer-ionic
liquid transducers. The measured conductivities of water hydrated Nafion electro-spun fibers are
16.8 mS/cm, which are lower than the nominal 110 mS/cm that of H+ Nafion membranes. The
uptake is measured to be around 250 wt % compared to 58 wt % obtained in Nafion films. The
ionic conductivity of 110 wt % swollen ionic liquids-Nafion mat composite is computed to be 0.9
mS/cm compared to 0.3 mS/cm in ionic liquid-Nafion membrane composite. The speed of response
in actuators with an ionic liquid- NafionTM mat is 1.34 %/s compared to 0.88 %/s for that in ionic
liquid NafionTM film transducers.
Stabilization of Thermoelastic Unstable Postbuckling in Cylindrical Piezolaminated Panels
Authors: Oh Il Kwon , Whang Won Gul , Kim Dong Hyun , Lee In
Published: March 2009

In this study, the stabilization of thermoelastic unstable postbuckling in cylindrical
piezolaminated panels was investigated by applying piezoelectric actuation. In order to derive the
finite element equations of motion of the active piezolaminated cylindrical panels, the total
Lagrangian formulation was derived using the Hamilton’s virtual work principles for largely
deformed structures with small strain. For the purpose of finding the load-displacement tracking, a
cylindrical arc-length method was applied to the iterative Newton-Raphson scheme. Present results
show that the eccentric piezoelectric patch can passively remove the unstable postbuckling and the
snap-through without piezoelectric actuation. Also, the thermoelastic snap-through can be
successfully suppressed by using a piezoelectric actuation.
Monitoring Method of Steel Reinforcement Corrosion Rate in Concrete
Authors: Saito Hiroyuki
Published: March 2009

Steel reinforcement concrete is one of the most widely used composite materials in
architectural and civil engineering. The alkaline of concrete makes steel passive state, so the steel bars
in conrete are kept in anti-corroded phase. Carbon dioxide in atmosphere, however, chemically reacts
to the alkaline components in long term, and the passive state of steel is missing. Steel corrosion in
concrete is not visible but it may cause decaying buildings or civil construction. The author developed
the electrochemical measurement method of monitoring steel corrosion rate in concrete. With the
measurement method, the author measured the variety of corrosion rates of steel reinforcement in
several atmospheres, such as indoors, outdoors, in-water, underground, and so on. In this paper,
found and analyzed mechanisms of steel corrosion in those atmospheres are mainly shown. For an
interesting result, the most corroded sample is not the sample exposed outdoor, nor exposed in water,
but the sample exposed in wet room. This may cause the diffusion balance of oxygen and water in
concrete.
Preparation and Dielectric Behaviour of Magnetoelectric HoMnO3-BaTiO3 Composites
Authors: Wu Y.J. , Zhang H. , Wan J.G. , Zhao S.F. , Liu J.M. , Wang Guang Hou
Published: March 2009

In this work, we report the magnetoelectric HoMnO3-BaTiO3 composites prepared by the
solid-state reaction method. X-ray diffraction and scanning electron microscopy were used to
characterize the phase composition and structures of the composites. The material/impedance
analyzer was used to investigate the dielectric properties of the composites. It is shown that the
composite consists of both ferroelectric ordering and magnetic ordering. The addition of BaTiO3
decreases the antiferromagnetic phase transformation temperature of the HoMnO3, indicating that
there exists the coupling interaction between BaTiO3 and HoMnO3 phases.
SiO2 (core)-TiO2 (shell) Structure as Catalyst Support for Oxidation of CO at Low Temperatures
Authors: Zong Zi Yi , Yin Xi Jiang , Lew Li Fang , Tan Soo Yee
Published: March 2009

In this study, TiO2 was successfully coated on Stober silica beads followed by depositing Au
nanoparticles on this core-shell structure. The size of the Au nanoparticles was well controlled in the
range of 2 – 7 nm. This composite exhibited high thermal stability. When used as a model catalyst for
oxidation of CO at low temperatures, the Au/TiO2/SiO2 showed a much higher catalytic activity than
the Au/SiO2 and Au/TiO2(P25) catalysts.
Size Effects on Miscibility and Glass Transition Temperature of PS/TMPC Blend Films: a Simulation and Thermodynamic Approach
Authors: Ao Zhi Min , Jiang Qing
Published: March 2009

The size dependent miscibility of binary polymer blend films of polystyrene (PS) and
tetramethylbisphenol-A polycarbonate (TMPC) is studied by the molecular dynamics (MD)
simulation in the way of computing Flory-Huggins interaction parameter, χ, of the blend films,
which determines the blend films compatibility. It is found that the miscibility of the two polymers
decreases as the film thickness D decreases. After that, the size dependent glass transition
temperature Tg(w,D) of the two polymers blend films in miscible ranges are determined by
computer simulation and the Fox equation where w is the weight fraction of the second component.
UV-Blocking Properties of Silica/Titania Hybrid Nanocomposites
Authors: Zhang Yi He , Xin J.H. , Daoud W.A. , Hao Xiang Yang
Published: March 2009

Silica nanoparticles and silica/titania hybrid nanocomposites were synthesized by sol-gel
processes, and padded on cotton fabric. The sizes of these particles ranged from tens to hundreds of
nanometers. The morphologies of nanoparticles and hybrid nanocomposites were characterized by
high magnification field-emission scanning electron microscope (FESEM). The UV-blocking
properties of untreated and treated fabrics with silica/titania nanocomposites were studied and
discussed.
Bi-Stable Composites with Piezoelectric Actuators for Shape Change
Authors: Bowen Chris R. , Salo A.I.T. , Butler R. , Chang E. , Kim H.A.
Published: March 2009

Unsymmetrical carbon fibre/epoxy composites with bonded piezoelectric fibre actuators
were investigated as a means to shape change, or morph, composite structures. A carbon fibre
cantilever was examined along with its response to applied strains (from piezoelectric actuators), with
emphasis on the characterisation of shape/deflection and the reproducibility of the shape/deflection of
the structure.
Piezoelectric Materials for Biomedical Applications
Authors: Ma Jan , Li Tao , Chen Yan Hong , Lim T. Han , Boey F.Y.C.
Published: March 2009

A piezoelectric microactuator for minimally invasive surgery procedures was developed
using the piezoelectric tube actuator. The tube was fabricated by electrophoretic deposition of a doped
PZT powders on the graphite rod substrate and co-sintering. The obtained tube shows maximum
strain 0.045% in 31 mode and coercive field 1.5 kV/mm under static condition. Under dynamic
condition, bending and longitudinal vibration modes can be identified from impedance spectrum and
simulation. Theoretical analysis indicates that the displacement of the two modes depends on the
geometry, material property, driving condition and damping conditions. The developed device uses
bending mode to create rotation mechanical motion, and longitudinal mode to produce ultrasonic
energy to soften and break up the target into fragments.
Sheet-Layer Microstructure and Toughness Mechanism of Shinbone
Authors: Chen Bin , Peng Xiang He , Wu Xin Yan
Published: March 2009

Most structural materials existing in nature take the form of composite. After centuries’
evolution, these materials gain highly optimized microstructures and performances. In this work, a
kind of natural biomaterial, shinbone, is observed with a scanning electron microscope (SEM). The
observation result shows that the bone is a bioceramic composite consisting of hydroxyapatite
layers and collagen matrix. The observation also shows that the hydroxyapatite layers are composed
of hydroxyapatite sheets. The hydroxyapatite sheets are of thin and long shape and parallel
distribution along the orientation of the maximum main stress of the bone. The shape and
distribution of the hydroxyapatite sheets may endow the bone with favorable fracture toughness,
which is analyzed and illuminated based a representational model of the hydroxyapatite sheets and
the idea of maximum pullout force.
Hydroxyapatite Films Deposited on TiN and TiO2 Buffer Layers by Radio-Frequency Magnetron Sputtering: Comparative Study
Authors: Wu Xiao Chen , Zhong X.X. , Zhou Wei , Yuan Lu Qi , Shu Qi Wei , Xia Yu Xing
Published: March 2009

A comparative study was presented to demonstrate the clear influence of the different buffer
layer (TiN and TiO2) on the HA film. In this study, magnetron sputtering was applied for different
film deposition. Nano-indentation was used to examine the mechanical properties of the HA film on
both TiN and TiO2 buffer layers. It is found that HA film on TiN buffer layer is harder and the HA
film on TiO2 buffers is more rigid. Further more, the simulated body fluid (SBF) soaking test was
selected to investigate the properties of the HA/TiN and HA/TiO2 films in the physiological media.
The obvious delamination was observed on the surface of HA film on TiN buffer layer, while the
surface morphology of HA film on TiO2 buffer layer remained nearly unchanged. The result
indicated that TiO2 buffer layer shows a better interfacial bonding to the HA film.
Damage Detection in CFRP Bonded Structures by Using Fiber Bragg Grating Sensors as Ultrasonic Wave Receivers
Authors: Takeda Nobuo , Okabe Y. , Kuwahara J. , Ogisu Toshimichi , Kojima Seiji
Published: March 2009

The authors developed a damage detection system that generates ultrasonic waves with a
piezo-ceramic actuator and receives them by a fiber Bragg grating (FBG) sensor. In this research, this
system was applied to evaluate debonding progress in CFRP skin/stringer bonded structures. FBG
sensors were bonded on the stringer or embedded in the adhesive layer. Then, ultrasonic wave at
300kHz was propagated through the debonded region, and the wavelet transform was applied to the
received waveform. After that, a new damage indexand a correlation coefficient were calculated from
the distribution of the wavelet transform coefficient. As a result, the damage index increased and the
correlation coefficient decreased with an increase in the debonded area. Hence the length of the
debonding between the skin and the stringer could be well evaluated.
Synthesis of Fine Nickel Powders by Solvothermal Method
Authors: Ye Yin , Yuan Fang Li , Zhou Li Min , Huang Hai Tao
Published: March 2009

Fine nickel powders have been prepared by chemical reduction between nickel acetate and
alcohol under solvothermal conditions. The effect of adding surfactant and varying solvent on the
particle size of the as-synthesized nickel powders have been explored. SEM, XRD and TG were
employed to characterize the size, morphology, crystalline structure and the thermal stability of the
as-synthesized nickel powders. It is revealed that the FCC-structured nickel powders are of uniform
spherical shape with good crystallinity and thermal stability. Typically, nickel powders with an
average size of 300 nm were obtained at 200°C for 8 h using 0.04 mol/L solution of
Ni(CH3COO)2·4H2O in n-butyl alcohol under solvothermal conditions.
Effect of Whisker Orientation on Mechanical Properties of Hydroxyapatite-SiCw Composite Bioceramics
Authors: Niu Zong Wei , Li Li
Published: March 2009

Effect of whisker orientation on mechanical properties of hydroxyapatite-SiCw composite
bioceramics was studied in this paper. Experiment results show that the mechanical properties of the
material are the best when the tensile stress acted on the composite material is parallel with the hot
pressing plane or the shearing stress is normal to the hot pressing plane, and they are the worst
when the tensile stress acted on the composite material is normal to the hot pressing plane or the
shearing stress is parallel with the hot pressing plane. This will offer great guidance for practical
applications of the hydroxyapatite-SiCw composite bioceramics.
Design of a Collagen/Silk Mechano-Compatible Composite Scaffold for the Vascular Tissue Engineering: Focus on Compliance
Authors: Couet Frédéric , Rajan Navneeta , Vesentini Simone , Mantovani Diego
Published: March 2009

One of the merging methods to produce tissue-engineered vascular substitutes is to
process scaffolds to direct the regeneration of vascular tissues. Collagen, as one of the main protein
in the vascular extracellular matrix, is one of biopolymers that exhibits a major potential for
scaffold technology. However, gels made from reconstituted collagen generally exhibit poor
mechanical properties and limited manipulability. Therefore, adding a reinforcement to the scaffold
to make the structure resist to the physiological constraints applied during the regeneration
represents a valid alternative. Silk fibroin is an interesting reinforcing candidate being a
mechanically strong natural fibre, susceptible to proteolytic degradation in vivo and showing
acceptable biological performances. Therefore, the aim of this study was to develop a model of a
composite scaffold obtained by controlling the filament geometry winding of silk fibroin in the
collagen gel. A finite element model taking into account the orthotropic elasticity of arteries has
been combined with classic laminate theory applied to the filament winding of a tubular vessel. The
design of the small structure susceptible to scaffold the vascular tissue regeneration was optimised
by mean of an evolutive algorithm with the imperative to mimic the experimentally measured
mechanical properties (compliance) of a native artery.