bluuebunny/crossref_metadata_2025 huggingface dataset:
The Influence of Antagonist Radii on Friction and Wear of Dental Ceramics
Authors: Yu Hai Yang , Gao Shan Shan , Cai Zhen Bing , Zhu Min Hao
Published: March 2009

The friction and wear behavior of dental ceramics (Vita VMK95) against uniform Si3N4
balls has been investigated using a small amplitude reciprocating apparatus under simulated oral
conditions. The variables of ball radii (2mm, 6 mm, 13mm, and 21mm), load (10N, 20N, 30N, and
40N), reciprocating amplitude (200(m), frequency (2Hz) and use of artificial saliva lubrication or no
lubrication were selected. Tests lasting up to 10,000 cycles were conducted. The wear scars of the
samples were characterized with 3-D con focused laser-scanning microscope. The wear depths were
analyzed statistically. The correlations between the wear behaviors and antagonist radii were also
compared. The results show the friction coefficient of dental porcelain goes up with the decreasing of
antagonist radii, and the wear depth decreases with the antagonist diameters. Load and lubrication
effect is significant for friction coefficient and wear depth. The friction and wear mechanism of dental
ceramics was characterized by abrasive wear and delaminating.
Synthesis of Poly(ε-Caprolactone)-Organosiloxane Hybrid Containing Amine Group
Authors: Rhee Sang Hoon , Lee Sun Ja , Kang Young Mi , Lee Yong Keun , Lim Bum Soon , Lee Seung Jin
Published: March 2009

Novel poly(ε-caprolactone)-organosiloxane hybrid containing amine group was
synthesized through sol-gel method. Triethoxysilane end-capped poly(ε-caprolactone) was prepared
by reaction with α,ω-hydroxyl poly(ε-caprolactone) and 3-isocyanatopropyl triethoxysilane. It was
then hydrolyzed and co-condensed with aminopropyl triethoxysilane through sol-gel method. The
success of hybridization was evaluated by FT-IR by new formation of siloxane group. Osteoblast-like
cell responses were assessed on this new hybrid material for the potential application as a bone tissue
engineering scaffold. The cell responses were compatible with those on pure poly(ε-caprolactone)
used as a control.
Guided Tissue Regeneration of the Mixture of Human Tooth-Ash and Plaster of Paris in Dogs
Authors: Ku Ha Ra , Jang Hyun Seon , Kim S.G. , Jeong Moon Jin , Park Joo Cheol , Kim Heung Joong , Kwon Young Sun , Kim Chong Kwan , Kim Byung Ock
Published: March 2009

This study evaluated the efficacy of periodontal tissue regeneration using guided tissue
regeneration (GTR) with a mixture of tooth ash and plaster as a bone substitute material in the
treatment of class II furcation defects in dogs. GTR was performed at the site of a surgically formed
mandibular premolar bifurcation area in dogs. Four adult dogs were used in the animal study. The
animals were in a good periodontal state without any systemic disease. A resorbable membrane
(Bio-Gide®, Swiss) and bone graft material using a mixture of tooth ash and plaster were used to
examine the biological activity. The defect in the control group was filled a Bio-Gide® only. For the
experimental group, the defects were filled with a mixture of tooth ash and plaster and covered by a
Bio-Gide®. Oral rinsing with 0.12% chlorhexidine was performed twice a day for 2 weeks. In
control group, new bone formation was observed adjacent to the preexisting bone. Soft tissue
ingrowth was also noted. In experimental group, new lamellar type trabecular bone formation as
well as centum and PDL regeneration was observed in the base of the infrabony pocket. More bone
regeneration would be expected when GTR is performed using a mixture of human tooth-ash and
plaster of Paris as a bone graft material.
In Vitro Growth of Aragonite Crystal on Nacre Surface
Authors: Luo Cheng , Xie Lei , Wang Xiao Xiang
Published: March 2009

In an effort to investigate the growth mechanism of nacre, a conventional vapor diffusion
method for CaCO3 crystal precipitation was applied to in vitro growth of calcium carbonate on
freshwater H. cumingii Lea shell. In a 10mM/L CaCl2 solution without any additives, aragonite
deposit was obtained on the nacre surface, specifically at the edges of nacreous tablets. At the early
stage of the deposition (up to 4 hr), the deposit did not take any specific form. After 12hr of
deposition, the deposit exhibited faceted morphology characteristic of crystalline. Further increasing
the deposition time resulted in the formation of well-faceted crystals of tower-like shape. Both
Raman spectra and X-ray diffraction patterns showed that the deposit consists of aragonite
polymorph of calcium carbonate.
Synthesis and Dispersion of Magnetic Nano-Particles by a Surfactant-Mediated Approach
Authors: Hou P. , Sun J. , Zhou S.B. , Weng Jie
Published: March 2009

Magnetic nano-particles of around 20nm synthesized by poly-ethylene glycol (PEG) and
sodium oleate mediated approach show well stability without sediment during 6 months. Upon
treated through the modification procedure, magnetic nano-particles have a weakly physical bond
with PEG, meanwhile a strong bond with sodium oleate. Naked magnetic nano-particles present
positive charges on the surface, while turn to be negative when modified with sodium oleate, which
suggest that the hydrophilic carboxyl on the surface of the nano-particles is outward. Magnetic
property of the nano-particles changes according to the concentrations of reactants and surfactant.
Osteogenic Activity of MG63 Cells on Hydroxyapatite/Collagen Nanocompsosite Membrane
Authors: Kikuchi Masanori
Published: March 2009

The hydroxyapatite/collagen (HAp/Col) nanocomposite membrane was prepared from
the HAp/Col nanocomposite fibers. The HAp/Col membrane crosslinked by a vacuum heating
showed 14±2 (dry) and 1.0±0.1 (wet) MPa in tensile strengths that were enough strength to operate
in both cell culture and surgical operations. Histological observation and total DNA amount
analysis demonstrated that human osteoblastic cells, MG63, derived from osteosarcoma on the
HAp/Col membrane adhered and proliferated well as the same as those on tissue culture polystyrene
(TCPS). Real-time polymerase chain reaction analyses indicated that alkaline phosphatase gene
expression on the HAp/Col membrane was 1.4 times greater than that on TCPS. These results
suggested that the HAp/Col nanocomposite membrane can be utilized in bone tissue engineering
scaffold as well as bone filler.
Characterization and Antibacterial Effect of a Novel Nanocomposite Membrane
Authors: Bai Shi , Mo An Chun , Xian Su Qin , Zuo Yi , Li Yu Bao , Xu Wei
Published: March 2009

In this experiment, un-dried silver-hydroxyapatite-titania nanoparticles slurry was used to
make membrane with Polyamide-66 by co-polymerization method. The morphology, chemical
components and structures of the membrane were characterized by AAS, XRD, SEM and EDX. S.
aureus, E. eoli, P.gingivalis, F.nucleatum and S.mutans were utilized to test the antibacterial effect.
XRD results demonstrated that the membrane have characteristic diffraction peaks of pure HA. A
homogeneous distribution of the Ca, P, Ti, and Ag element in the membrane was confirmed by
EDX. Both surface and section showed porous structure which was confirmed by SEM and the
holes size was average 20-30μm. The bacteria assay reflects to the antibacterial effect, 56.31 % of
S. aureus and 50.10 % of E. eoli were killed after 24 hours incubation. However, 91.84 % of P.
gingivalis, 90.64 % of F. nucleatum and 90.49 % of S. mutans were killed and pictures of SEM
showed obviously fewer cells on the surface. So the nanocomposite membrane could be one of the
bioactive materials with antibacterial properties for oral GBR technique.
The Construction and Characterization of Nano-FHA Bioceramic Coating on Titanium Surface
Authors: Cai Xiao Xiao , Gong Ping , Man Yi , Chen Zhi Qing , He Gang
Published: March 2009

This research was aimed at the construction and characterization of nano-FHA bioceramic coating on titanium surface. Nano-FHA coating was constructed on the surface of commercially pure titanium by sol-gel route. X-ray diffraction (XRD), scanning electromicroscope (SEM) and dissolution test was employed to characterize the obtained coating. In vitro cellular responses of osteoblasts to the coating were also evaluated by MTT assay, ALP assay and SEM observation. Conventional HA coatings and commercially pure titanium (cpTi) were taken as control. Results show the nano-FHA bioceramic coating has good crystallization and homogeneous, nano-scale surface morphology. The dissolution rate of the coating is favorable. The in vitro osteoblasts culture exhibits satisfactory bioactivity.
Bioactivity and Mechanical Property of Starch-Based Organic-Inorganic Hybrids
Authors: Miyazaki Toshiki , Yasunaga S. , Ishida Eiichi , Ashizuka Masahiro , Ohtsuki Chikara
Published: March 2009

So-called bioactive ceramics bond to living bone through the apatite layer formed on their surfaces in the body. The apatite deposition is triggered by dissolution of calcium ion (Ca2+) and by silanol (Si-OH) group formed on the surfaces of the ceramics. It is expected that organic modification of these components would produce bioactive materials with high flexibility. In this study, we examined bioactivity and mechanical properties of the organic-inorganic hybrids from starch by modification with silanol group and calcium ion. Effect of cross-linking agent was also investigated. The obtained hybrids showed bioactivity and mechanical properties analogous to those of human cancellous bone by appropriate control in their compositions. Addition of cross-linking agent to improve mechanical strength of the hybrids did not decrease their bioactivity.
Comparison Research between Porous HA/PLA Composite and Bone-Derived Material in Repairing Periodontal Defects
Authors: Tan Zhen , Zhao Qing , Wang Yi , Yuan Quan , Gong Ping
Published: March 2009

GTR treatment alone has not led to predictable new periodontal tissue reconstruction.
Recently, various types of tissue substitutes and alloplastic graft have been used in conjunction with
the GTR technique. The aim of this study was to evaluate whether nano-hydroxyapatite/Polylactic
acid (nHA/PLA) and bone-derived materials would be useful in the treatment of class II furcation, in
order to provide an ideal bone replacement material for periodontal treatment. Mucoperiosteal flap
was raised on the buccal aspects of the experimental teeth and class Ⅱ furcation defects were created
surgically on premolars of each quadrant in 3 dogs. The defects were randomly repaired with
nHA/PLA and collagenic membrane, partially deproteinized bone (PDPB) and collagenic membrane.
Blank control group was stayed. Speciments obtained in 6 weeks were evaluated with general
observation, histological microscopic analysis. The specimens of the implanted groups exhibited
periodontal regeneration including newly formed cementum, periodontal ligament and new bone.
The new-formed bone area in sites receiving nHA/PLA and PDPB combined with collagen
membrane was greater than that in blank group.The new bone area in PDPB was smaller than that in
nHA/PLA. nHA/PLA would be better alternative for periodontal regeneration.
Precipitation of Carbonated Calcium Phosphate Powders from a Highly Supersaturated SBF Solution
Authors: Hofmann Ingo , Müller Lenka , Greil Peter , Müller Frank A.
Published: March 2009

Hydroxy carbonated apatite (HCA) powders were prepared by precipitation from a modified SBF solution (5x M-SBF). The ionic concentrations were 5 times higher than in human blood plasma with the exception of Mg2+ and HCO3 - concentrations that were reduced in order to accelerate crystal growth. Spheroaggregates of HCA platelets with molar (Ca+Mg)/P ratios ranging from 1.44 to 1.56 were obtained after precipitation at 50 °C. The crystallite size in c-direction was approximately 20 nm and depending on the precipitation time a CO3 2- content of 1.8 to 5.2 wt.-% was determined. Using this low temperature precipitation method, HCA powders with a high specific surface area of 83 m2/g and a composition and crystallite size close to those of the mineral phase of human bone were obtained.
Apatite-Forming Ability of Polyglutamic Acid Gel in Simulated Body Fluid: Effect of Cross-Linking Agent
Authors: Sugino Atsushi , Miyazaki Toshiki , Ohtsuki Chikara
Published: March 2009

Development of the organic-inorganic hybrids composed of apatite crystals and organic polymer is expected to be an attractive material that has mechanical properties similar to natural bone as well as bone-bonding ability, i.e. bioactivity. It is reported that the carboxyl groups (-COOH) on the surfaces of the organic substrates act as a catalyst for induction of heterogeneous nucleation of apatite. The present authors previously showed that the apatite was successfully deposited on the polyglutamic acid gels containing abundant carboxyl groups through the biomimetic process, when they were priorly treated with calcium chloride solution. In this study, we fabricated the polyglutamic acid gels with different degree of cross-linking. Effect of the cross-linking on their ability of the apatite formation was examined in simulated body fluid (SBF). It was suggested that the apatite deposition on the polyglutamic acid gels is governed not only by the amount of –COOH that induces the heterogeneous nucleation of the apatite, but also by swelling property that controls local increase in degree of supersaturation with respect to the apatite.
The Effect of Initial pH on Morphology of Biomimetic Apatite Coating
Authors: Qu Hai Bo , Wei Mei
Published: March 2009

Bone-like apatite coatings were prepared using a biomimetic method in a simulated body
fluid (SBF). The effect of initial pH values on the surface morphology of biomimetic apatite
coating was studied. The coatings were characterized using X-ray diffraction and environmental
scanning electron microscope. It was revealed that the morphology of the biomimetic apatite
coating could be tailored by manipulating the initial pH of the SBF solution.
Novel Antibacterial Calcium Phosphate Cement
Authors: Kim Ji Hwan , Lee Doug Youn , Lee Sang Bae
Published: March 2009

The antibacterial brushite-forming calcium phospahte cements (CPC) were prepared using
an equimolar mixture of β-tricalcium phosphate (β-TCP) and monocalcium phosphate monohydrate
(MCPM) with chlorine dioxide (ClO2) generating powders (sodium chlorite and mixed acid
activator). The effect of ClO2 on cement setting time, compressive strength, and antibacterial property
of novel antibacterial CPC was investigated. The use of 0.3M citric acid solutions as liquid phase
enabled final setting times of 5~10 min. The setting time of antibacterial cement systems was
prolonged with increasing the amount of antibiotic used. Dry compressive strength was found to be in
the range between 9~15 MPa and increased with addition of ClO2 generating powders. Wet
compressive strength was slightly decreased compared to dry compressive strength after immersion
of cement samples in water for 24 h. The antimicrobial potency of the different cement formulations
was investigated using the agar diffusion method. The acidic brushite cement itself showed the
inhibitory effect for Streptococcus mutans. The inhibition zone was increased with the amount of
ClO2 generating powders. These results indicate that our novel antibacterial CPC have the great
potential to avoid the development of infections for preventive antibiotic therapy.
An In Vivo Comparative Analysis of the Intra-Operative Properties of Injectable Calcium Phosphate/Calcium Sulphate Based Bone Cements
Authors: Catalano Peter J. , Insley G.M. , Hess Brian
Published: March 2009

The aim of this work was to assess the mixing, transfer and handling, properties,
injectability, set time, wash-out characteristics, acceptance of hardware (i.e. stainless screws), and
their delivery/transfer systems of self hardening synthetic bone cements made from calcium
phosphate and calcium sulphate. Surgical procedures (i.e. cranioplasty) were performed on adult
Labrador dogs using seven different bone cements from various manufacturers. Direct comparison
of the defined intraoperative properties were evaluated and recorded. There is considerable
variability with respect to application properties among commercially available injectable synthetic
bone cements. Only one product was rated good to excellent in seven of the eight categories
evaluated (6-excellent, 1-good, 1-fair) based on in-vivo tests. This study outlines the critical
parameters required for successful implantation of cements that have to be understood when
designing new injectable bone cements for the future.
Biomineralization of Glass Fibre Reinforced Porous Acrylic Bone Cement
Authors: Puska Mervi , Forsback Ari-Pekka , Yli-Urpo Antti , Seppälä Jukka , Vallittu Pekka K.
Published: March 2009

Acrylic bone cements are used to fix joint replacements to bone. The main substance in
acrylic bone cement is biologically inert poly(methylmethacrylate), PMMA. The dense PMMA
polymer structure of cement does not allow bone ingrowth into cement. Therefore, the main focus of
our studies is to modify acrylic bone cement in order to improve its biological properties e.g., by
creating porosity in the cement matrix. The porous structure is in situ created using pore-generating
filler (i.e., 20 wt% of an experimental biodegradable polyamide) that is incorporated in acrylic bone
cement. The aim of this in vitro study was to investigate the biomineralization of acrylic bone cement
modified using an experimental biodegradable polyamide.
Surface Wettability Enhances Osteoblast Adhesion on Silicon-Substituted Hydroxyapatite Thin Films
Authors: Thian E.S. , Huang J. , Best Serena , Barber Zoe H. , Bonfield William
Published: March 2009

Crystalline hydroxyapatite (HA) and 0.8 wt.% silicon-substituted HA (SiHA) thin films
were produced using magnetron co-sputtering. These films were subjected to contact angle
measurements and in vitro cell culture study using human osteoblast-like (HOB) cells. A wettability
study showed that SiHA has a lower contact angle, and thus is more hydrophilic in nature, as
compared to HA. Consequently, enhanced cell growth was observed on SiHA at all time-points.
Furthermore, distinct and well-developed actin filaments could be seen within HOB cells on SiHA.
Thus, this work demonstrated that the surface properties of the coating may be modified by the
substitution of Si into the HA structure.
Novel Micro-CT Based 3-Dimentional Structural Analyses of Porous Biomaterials
Authors: Otsuki B. , Takemoto Mitsuru , Fujibayashi Shunsuke , Neo Masashi , Kokubo Tadashi , Nakamura Takashi
Published: March 2009

A porous structure comprises pores and pore throats with a complex three-dimensional network structure, and many investigators have described the relationship between average pore size and the amount of bone ingrowth. However, the influence of network structure or pore throats for tissue ingrowth has rarely been discussed. Bioactive porous titanium implants with 48% porosity were analyzed using specific algorithms for three-dimensional analysis of interconnectivity based on a micro focus X-ray computed tomography system. In vivo histological analysis was performed using the very same implants implanted into the femoral condyles of male rabbits for 6 weeks. This matching study revealed that more poorly differentiated pores tended to have narrow pore throats, especially in their shorter routes to the outside. Data obtained suggest that this sort of novel analysis is useful for evaluating bone and tissue ingrowth into porous biomaterials.
Layered Functional Ceramics via Misted Chemical Solution Deposition
Authors: Scott J.F. , Morrison F.D. , Miyake M. , Tatsuta T. , Tsuji O
Published: March 2009

A review is given of "misted" CSD deposition. This technique uses stoichiometrically
correct sol-gel solutions but is not a spin-on process. Instead a monodisperse mist of droplets as
large as 3 microns in diameter or as small as 0.3 microns is deposited on a substrate. This
technique has the great advantage over sol-gel spin-on processing in that it is suitable for nonplanar
structures, including nanotubes and nano-wires. One could coat a variety of objects with this
technique, including anything from non-planar flash-goggles to a parabolic mirror or focal-plane
array of pyroelectric detectors. Yet it is much simpler and less expensive than conventional
chemical vapour deposition (CVD). We illustrate its use with functionally graded layers on
platinised silicon wafers, on nanotubes of piezoelectrics, and most recently [Pollard, Gregg, et al.]
on 100 Gbit/cm2 arrays of Pt nanowires on Si substrates (the latter are 30-nm diameter, spaced 50
nm apart, embedded in porous alumina and capped with lead zirconate titanate capacitors).
Distributed Fiber Optic Strain Sensing with Embedded Small-Diameter Optical Fibers in CFRP Laminate
Authors: Mizutani Tadahito , Nishi Takafumi , Takeda Nobuo
Published: March 2009

Although demand for composite structures rapidly increase due to the advantages in
weight, there are few effective assessment techniques to enable the quality control and guarantee
the durability. In particular, an invisible microscopic damage detection technology is highly
required because damages such as transverse cracks, debondings, or delaminations can lead to the
critical failure of the structures. Among many non-destructive evaluation (NDE) methods for
composite structures, fiber optic sensors are especially attractive due to the high sensitivity, the
lightweight, and the small size. In the current trend of the structural health monitoring technology,
fiber Bragg gratings (FBG) sensors are frequently used as strain or temperature sensors, and
Brillouin scattering sensors are also often used for a long distance distributed measurement. The
Brillouin distributed sensors can measure strain over a distance of 10km while a spatial resolution
was limited to 1m. Some novel sensing method is proposed to improve the spatial resolution. The
pulse-prepump Brillouin optical time domain analysis (PPP-BOTDA) is one of the latest distributed
sensing applications with a cm-order high spatial resolution. The PPP-BOTDA commercial product
has the spatial resolution of 10cm, and can measure the strain with a precision of ±25og. This
precision, however, can be achieved by using conventional single-mode optical fibers. In our
research, small-diameter optical fibers with a cladding diameter of 40om were embedded in the
CFRP laminate to avoid the deterioration of the CFRP mechanical properties. Thus, in order to
verify the performance of PPP-BOTDA, the distributed strain measurement was conducted with the
small-diameter optical fibers embedded in the CFRP laminate.
Optimal Placement of Sensors for Damage Characterization Using Genetic Algorithms
Authors: Yan Yun Ju , Chen Huan Guo , Jiang Jie Sheng
Published: March 2009

Sensor data are the basis for health assessment of complex structural systems. Careful
selection and logical layout of sensors is critical to enable the high reliability of system health
assessment. This paper presents a methodology how to use a minimum number of sensors, and what
locations of them should be placed, so that the voltage signals received from the sensor can be used to
detect both presence and extent of damage. In this study, an optimization procedure is developed
using Genetic Algorithm (GA) to determine the location of piezoelectric sensor for damage detection
in a composite wingbox. A new damage index using all differences in voltage signals decomposed by
wavelet transform is proposed. Results show that the proposed method is available at determining
number and location of sensors for structural damage detection using piezoelectric patch sensors.
Perovskite Relaxor Ferroelectric Thick Films Directly Grown from Oxide Precursors by a Low Temperature Hydrothermal Process
Authors: Fan Hui Qing , Chen Xiu Li
Published: March 2009

Relaxor-based lead-lanthanum-zirconate-titanate (PLZT) thick films were prepared on Ti
substrates by a simplified hydrothermal method, in which the precursors were heated to 150 oC with
durations from 8 to 32h. The mixture of oxides was used as the staring materials. The smooth PLZT
films with a single perovskite structure were obtained through the synthesis route. Structural and
morphological studies were carried out on hydrothermally synthesized films. The influences of the
mineralizer concentration on the structural, morphological, and physical characteristics of the
particles are studied. Phase characterization and crystal orientation of the PLZT thick films were
investigated by x-ray diffraction analysis (XRD). The dielectric constant and dielectric loss of the
PLZT thick films were measured. In the frequency range from 1000 to 100 MHz, the dielectric
constant and the dielectric loss were very steady.
Dielectric Properties of AlN/Polymer Composites for Electronic Substrate Application
Authors: Zhang Jie , Fan Hui Qing , Ke Sha Ming , Shi Yun Ze , Zeng Xian Hua , Bi Mei Tian , Huang Hai Tao
Published: March 2009

The fabrication processing, dielectric properties and thermal properties of polymer-matrix
composites containing AlN particles (10μm) for electronic substrates and microelectronic packaging
applications were investigated. The epoxy resin (E-51) is used as the matrix, and the dispersion of the
AlN in the composites is varied form 0 vol% to 40 vol%. The microstructures of the polymer-matrix
composites are observed through scanning electron microscopy (SEM). With increasing the AlN
content, thermal conducting of composites is improved, while the composites still keep the relatively
low dielectric constant and dielectric loss. According to the dielectric properties dependence on
frequencies (1kHz-10MHz) of the composites, the Cole-Cole plot is analyzed. The dipole relaxation
in the composite is induced, and it is suggested that the air layer exit between the epoxy resin and the
AlN particles.
Shear Horizontal Waves in a Piezoelectric-Piezomagnetic Tri-Material
Authors: Liu Jin Xi , Zhao X.F. , Soh Ai Kah
Published: March 2009

The propagation of shear horizontal (SH) wave is studied in a tri-material composed of a
piezomagnetic layer and two semi-infinite piezoelectric half-spaces. These materials are hexagonal
(6mm) crystals. A dispersion relation is exactly derived. The numerical results show the existence of
the SH wave and its dispersion characteristics. These may be useful for the applications of
piezoelectric-piezomagnetic media in the microwave technology.
Modelling Liquid Composite Moulding Processes Employing Wood Fibre Mat Reinforcements
Authors: Umer R. , Bickerton S. , Fernyhough Alan
Published: March 2009

Liquid Composite Moulding (LCM) processes are commonly used techniques for the
manufacture of advanced composite structures. This study explores the potential of wood fibres as
reinforcement for LCM preforms, considering mats produced using dry and wet methods. The
compaction response of these mats has been investigated with and without the presence of a test fluid.
Permeability of these mats was also measured as a function of fibre volume fraction. Reinforcement
permeability and compaction response data were used to model two different LCM processes. The
simulation results have been compared with experiments.
A Signal Processing Approach for Elastic Wave-Based Structural Health Monitoring Using Active Piezoelectrics
Authors: Yang Chun Hui , Su Zhong Qing , Ye Lin , Zhou Li Min , Hodgson Peter
Published: March 2009

A series of digital frequency filters (DFFs) were designed to screen diverse noises and the
spectrographic analysis was conducted to isolate complex boundary reflection, which obscures the
damage-induced signals. The scale-averaged wavelet power (SAP) technique was applied to enhance
the measurement accuracy of Time of Flight (TOF). As an example, the propagation characteristics of
elastic wave in a structural beam of square cross-section were analyzed using such an approach and
verified experimentally and numerically, with the consideration of the complicated wave scatter
caused by the non-ignorable section dimensions.
Rate-Dependent Strain Generated Potentials in Ossointegrated Implant-Bone Composite
Authors: Hong Jung Hwa , Park Young Hwan , Ko Sang Ok
Published: March 2009

Osseointegration (OI) could be described as the modality for stable fixation of titanium
implant to bone structure. The OI has become a realized phenomenon of importance in the dental and
rehabilitation sciences since recently developed dentures and artificial limbs are directly attached to
human skeleton by using osseointegrated (OI) implants. Previously, a study showed that bone strain
generated potential (SGP) that is an electrical potential and considered to be generated by fluid flow in
bone could be used as a parameter to examine the amount of OI on bone-implant interface. Since no
study was performed to understand effects of loading rate changes on behavior of SGP for the
bone-implant composite, rate dependent behavior of SGP was investigated in this study. Four
different displacement rates, 100, 200, 500, and 1000 mm per minute were applied to the
bone-implant composites. During the compression tests, SGPs were also measured. Magnitude of
SGP was found to be significantly increased as the rate increased for OI bone-implant composite. In
contrast, the time duration of SGP was decreased as the rate increased. These results could imply that
the temporal SGP behavior of bone-implant composite is significantly affected by the loading rate.
Improvements of Stiffness and Strength of Bio-Resorbable Bone Nails by the MFC-Concept
Authors: Friedrich Klaus , Hoffmann Juergen , Evstatiev Mihail , Ye Lin , Mai Yiu Wing
Published: March 2009

In contrast to the classical composites, microfibrillar reinforced composites are not
prepared via melt blending of the matrix and the reinforcing material. In fact, the reinforcing
elements of this composite, the microfibrils, are created during processing. This advantage allows
the manufacturing of a full biodegradable composite material with improved mechanical properties.
Basing on a blend of two common biodegradable polymers, polylactide and polyglycolide, this new
composite shows promising values under ambient conditions.
Thermophysical and Mechanical Properties of β-Tricalcium Phosphate Reinforced Polyhydroxybutyrate and Polyhydroxybutyrate-Co-Hydroxyvalerate Composites
Authors: Liu Ya , Wang Min
Published: March 2009

Two series of bioactive and biodegradable composite materials consisting of particulate
β-tricalcium phosphate (β-TCP) and polyhydroxybutyrate (PHB) and its copolymer
polyhydroxybutyrate-co-hydroxyvalerate (PHBV) were produced and investigated for bone tissue
repair. A manufacturing route employing injection moulding was established for producing the
biomedical composites. In the process, plates of composites containing 10%, 20%, 30% or 40% by
volume of micro-sized TCP particles were successfully injection moulded for both TCP/PHB and
TCP/PHBV composites. Thermal properties of as-produced TCP/PHB and TCP/PHBV composites
were systematically evaluated using differential scanning calorimetry (DSC). The mechanical
performance of TCP/PHB and TCP/PHBV composites was assessed using dynamic mechanical
analysis (DMA).
Modelling of Extrusion Behaviour of Biopolymer and Composites in Fused Deposition Modelling
Authors: Ramanath H.S. , Chandrasekaran M. , Chua Chee Kai , Leong Kah Fai , Shah Ketan D.
Published: March 2009

Processing of polymers plays an important role in application of polymers in biomedical
engineering, for instance in manufacture of scaffolds for tissue engineering applications. Rapid
prototyping technologies like fused deposition modeling (FDM) has been widely used in processing
polymers for biomedical applications. The present work is focused on modeling of flow behavior in
the extrusion liquefier in FDM. A finite element (FE) model of extrusion liquefier was constructed
on ANSYS after verification of internal geometry using X-ray imaging. Polycaprolactone (PCL) is
used as the base bio polymer for analysis. Experiments were carried out to characterize the physical
properties like thermal conductivity, specific heat, viscosity and shear thinning property of PCL.
These values were used for behavior modeling in the extrusion liquefier. The thermal and flow
behavior in the extrusion liquefier is studied by varying input conditions and analyzing the velocity,
pressure drop profiles at various zones of extrusion liquefier. Experimental values of parameters
and the simulated flow model showed good correlation. The current model can be extended to
predict the flow behavior of PCL/ Hydroxyapatite composites in a FDM head which in turn will
reflect on the quality of scaffold constructed using the Biocomposite.
Effect of Artificial Cartilage Made up of Smart Material of Nanostructure on Dispersion in Poorly Conducting Macromolecular Components in Synovial Joints
Authors: Rudraiah N. , Ng C.O. , Nagaraj C.
Published: March 2009

Electrohydrodynamic (EHD) dispersion of macromolecular components in a biological
bearing consisting of a poorly conducting synovial fluid both in the cavity of the bones and in the
bounding porous cartilage of finite thickness is investigated using Taylor’s [4] dispersion model . It
is shown that artificial joints involving smart materials of nanostructure discussed here work more
efficiently than the natural joints.
Electrochemically-Induced Deposition of Protein and Calcium Phosphate Coating on Titanium
Authors: Wang Hui , Lin Chang-Jian , Hu Ren , Ye Qing , Han Hui Juan
Published: March 2009

A nano-micro structured protein/octacalcium phosphate composite coating was prepared
by electrochemically-induced deposition (ED) onto titanium surface. The characterizations of XRD,
SEM and FT-IR indicate that the as prepared composite coating consists of protein and octacalcium
phosphate with a highly and hierarchically porous structure in nano-micro scale, similaring to the
natural bone structure.
Study on a Stiffness Design Method of Femoral Prosthesis Stem Using Fiber Reinforced Composites
Authors: Kawamura Takeshi , Kurashiki Tetsusei , Nakai Hiroaki , Zako Masaru , Sugano Nobuhiko , Yoshikawa Hideki
Published: March 2009

A femoral Prosthesis Stem made from composite material is investigating to apply to real body. The
purpose of this study is to propose a design method of novel composite stem. Finite element models of
stem and femur have been developed by using CT images. Some design parameters of the stem have
been described and the effect of mechanical properties on the femur has been also described and
compared with a traditional metal stem. The evaluation procedure for the stem has been proposed and
been applied to a composite stem. It is revealed that the stem made of composite is more effective than
the traditional stem made of metal.
Electrical Properties of Hot Press Sintered NASICON Ceramics
Authors: Zhu Dong Mei , Xie Zhang Long , Luo Fa , Zhou Wan Cheng
Published: March 2009

Sodium superionic conductor, NASICON ceramic (Na1+xZr2SixP3-xO12, x=2), was
hot-press sintered under different temperatures and the electrical properties of the obtained different
samples were investigated. Results show that the relative density of the ceramics can be improved
by hot-press process efficiently and the crystal size of the samples are closely related to sintering
temperature. With the increase of sintering temperature, both the density and the crystal size of
samples increase obviously, resulting in the increase of ionic conductivity of samples as the
sintering temperature. When the sintering temperature reaches 1150oC, the ionic conductivity of
sample is as high is 3.6×10-3S/cm, which is obviously higher than that of sample sintered at 1000oC
(2.13×10-3S/cm). As the frequency increase, the real parts and the imaginary parts of complex
dielectric constants for all the samples decrease in 8.2 GHz~12.4GHz frequency band. The ceramics
obtained at the higher temperature possess the higher dielectric constant.
Encapsulation of Carbonyl Iron Particles with Poly(Vinyl Butyral) and their Magnetorheology
Authors: You Jae Lim , Park B.J. , Jang I.B. , Choi Hyoung Jin
Published: March 2009

To enhance dispersion stability of magnetorheological (MR) fluids, hybrid magnetic
particles of carbonyl iron (CI)/ poly(vinyl butyral) (PVB) with core/shell microstrcutre (CI-PVB)
were prepared, since pure magnetic CI based MR fluid systems show severe sedimentation of the CI
particles due to the large density mismatch with the carrier liquid and difficulties in redispersion after
caking. The composite particles of CI-PVB have a lower density than that of the pure CI particles,
while exhibiting almost original magnetic property of the CI. Both CI and CI-PVB particles were
dispersed in mineral oil (20 vol%) and their MR characteristics were examined via a rotational
rheometer with a magnetic field supplier. Various characterizations of the CI-PVB particles were
performed via SEM, TEM and FT-IR. Both yield stress and flow curve of shear stress as a function of
shear rate of the MR fluids were investigated under applied magnetic field strengths.
Large Deformation and Failure Mechanism of Plain Woven Composite in Bias Extension Test
Authors: Zhu B. , Yu T.X. , Tao Xiao Ming
Published: March 2009

Large shear deformation of plain woven composite sheets and corresponding failure
mechanism are investigated by bias extension test. Digital image correlation analysis was conducted
on a series of photos taken during the test. Four typical phases were identified, and a theoretical
model of the large deformation is proposed from energy point of view. Numerical simulations have
also been carried out, but it will be reported in a subsequent paper.
Photoelastic Determination of Interfacial Shear Stresses in Model Composites
Authors: Zhao F.M. , Liu Z. , Jones F.R.
Published: March 2009

Phase-stepping photoelasticity has been used to study the fragmentation of an E-glass
fibre in epoxy resin and examine quantitatively the effect of a transverse matrix crack on the stress
transfer at an interphase. Unsized glass fibre was coated by plasma polymerisation with a
crosslinked conformal film of 90% acrylic acid and 10% 1,7-octadiene. The micro-mechanical
response at the fibre-matrix interphase and in the adjacent matrix has been described in detail using
contour maps of fringe order. From these, the interfacial shear stress profiles at fibre-break have
been calculated.
Preparation of TiB2/C Composites in a CVI Reactor
Authors: Kim Min Ki , Kim Dong Phil , Chung Gui Yung
Published: March 2009

Titanium diboride (TiB2) appears to be an attractive candidate for a high-temperature
fiber reinforced composites. Chemical Vapor Infiltration (CVI) has been carried out for the
preparation of TiB2/C composites. Titanium diboride has been deposited from the gas mixtures of
TiCl4, BCl3, and H2 in the furnace at the reaction temperatures between 850 to 950 °C and about 20
torr. Effects of infiltration parameters such as temperature, reaction time, and concentrations of
BCl3 and H2 have been studied. Analyses with SEM, TGA and XPS were carried out. The
amount of deposition in the preform increased with the increases of the reaction time, temperature
and the flow rate of BCl3. The activation energy of the whole deposition reaction could be
estimated from the Arrhenius plot.
Effective Stiffness of a Debonded Particle in Particulate Composites
Authors: Wada Akihiro , Nagata Yusuke , Motogi Shi Nya
Published: March 2009

In this study, partially debonded spherical particles in a particulate composite are analyzed
by three-dimensional finite element method to investigate their load carrying capacities, and the way
to replace a debonded particle with an equivalent inclusion is examined. The variation in Young’s
modulus and Poisson’s ratio of a composite with the debonded angle was evaluated for different
particle arrangements and particle volume fractions, which in turn compared with the results derived
from the equivalent inclusion method. Consequently, it was found that by replacing a debonded
particle with an equivalent orthotropic one, the macroscopic behavior of the damaged composite
could be reproduced so long as the interaction between neighboring particles is negligible.
Properties of Biodegradable Thermoplastic Starch/Ethyl Cellulose Composite
Authors: Tao Jie , Cui Yi Hua , Ji Xue Lai , Ma Li , Wo Ding Zhu
Published: March 2009

Since thermoplastic starch can not be used directly due to its poor properties in
processing, thermoplastic starch /ethyl cellulose composite is prepared by blending method in this
work. The effect of the composition and the structure on the properties of the composite is studied.
The results indicate that glycerin is a better plasticizer in the processing of the thermoplastic starch
compared to glycol. The mechanical properties of the thermoplastic starch are improved obviously
after blending with ethyl cellulose. The composite exhibits comprehensive properties as the content
of the ethyl cellulose is kept at 10%, which also has a reasonable cost.
Local Buckling Coefficient of Thin-Walled Pultruded FRP Compression Members
Authors: Joo Joo Hyung , Yoon Soon Jong , Park Ju Kyung , Cho Sun Kyu
Published: March 2009

Recently there has been an increased demand in the use of FRP materials as load-bearing
structural elements for the civil engineering applications, since FRP composite materials offer
superior properties to conventional structural materials used in civil engineering structures. Among
various production techniques, the pultrusion process has enabled the production of structural profiles
with large cross sections at relatively low cost. Pultruded structural members are generally
manufactured in the form of thin-walled member composed of plate elements and material properties
can often be assumed as orthotropic. Due to the relatively low geometrical stiffness, often combined
with low elastic modulus, the design of pultruded profiles is governed by the deflection or buckling
rather than the material strength. In this paper, the elastic local buckling coefficient of the pultruded
structural member having L-, T- and box-shape under the uniform in-plane compression was
investigated and approximate equation to find the local buckling strength was proposed by using the
classical orthotropic plate theory and energy method. The suggested equation can be used in the
development of the design criteria and local buckling analysis of pultruded structural members.
Development of Solid-Air Composites for Load Dispersion by Biomimetic Design - Load Dispersion Ability under Dynamic Loading Condition -
Authors: Tanaka Kazuto , Kamada Koji , Katayama Tsutao
Published: March 2009

Nature has developed many novel solutions and extracting these design solutions from
nature is known as biomimetics. Cancellous bone contains trabecular bone (solid) and marrow
(fluid), plays an important role for load transfer of the knee joint.
The objective of this research is to mimick the solid-liquid composition of the cancellous bone and
to develop the material that has the excellent load dispersion ability. In the previous research, the
solid-liquid composition of the cancellous bone has been modeled as solid-air composites that was
made with Al honeycomb and silicon films. Air pressure in cells affected the load dispersion
characteristic under static loading condition. In this study, to investigate the influence of the
compression speed, impact tests were carried out. We investigated the influence of directions of holes
to cell walls, foil thickness, hole diameter and the number of holes on the load dispersion ability.
Presence of silicon film and air in cells affected the load dispersion characteristic under dynamic
loading condition. Solid - air composition and relaxing local deformation by optimal design improve
load dispersion ability.
Improvement of Flexural Strength of RC Beams by Using the Multi-Layer Multi-Tensioning Method with CF Sheets
Authors: Kusaka Takayuki , Watanabe Keiko , Okubo Ken Suke , Namiki Hironori
Published: March 2009

A novel retrofitting method using extremely prestressed carbon fiber sheets, MLML
(Multi-Layer Multi-Tensioning) method, was proposed for improving the flexural strength of
reinforced concrete structures. The experimental results suggested that the crack initiation strength
and the energy absorbing capacity of RC beams could be largely improved by the MLMT method.
However, the advantage of the MLMT method was not so clear on the rebars yielding strength and
the ultimate flexural strength of RC beams, compared with the conventional methods.
Recycling and Its Effects on the Physical and Mechanical Properties of Wood Fibre Reinforced Polypropylene Composites
Authors: Beg M.D.H. , Pickering K.L.
Published: March 2009

This study investigates the effect of recycling/reprocessing on the physical and
mechanical properties of composites based on radiata pine (Pinus Radiata) fibre and polypropylene
(PP) with a maleated polypropylene (MAPP) coupling agent, produced using a twin-screw extruder,
followed by injection moulding. Composites containing 40wt% fibre and 4wt% MAPP were
assessed mechanically and thermally, as well as for moisture absorption after being recycled up to
eight times. Both the tensile strength (TS) and Young’s modulus (YM) of composites were found to
decrease linearly from 41 MPa and 4556 MPa respectively to 31 MPa and 3800 MPa for composites
recycled eight times. However, the elongation at break was found to increase with increased
recycling due to fibre damage that occurred during reprocessing and the associated reduction of
average fibre length, found to decrease from 2.36mm to 0.37mm after recycling eight times.
Thermal stability and moisture resistance of composites improved with recycling due to the
improvement of interfacial bonding between fibre and matrix.
Environmental Degradation of Flexural and Fracture Properties of Glass/Vinyl Ester Filament Wound Pipes
Authors: Gasem Zuhair M.
Published: March 2009

An experimental testing program is being conducted to evaluate the effects of
environmental exposure on the mechanical properties of glass/vinyl ester filament wound pipes.
The effects of artificial exposure on the flexural and fracture properties are reported in this paper.
Three point bending specimens were employed to characterize the flexural properties. Fracture
resistance was assessed using pre-cracked notched ring specimens. Specimens were exposed for
300, 1000, and 3000 hours in the environment of interest before testing at room temperature. The
exposure conditions presented in this paper include: dry heat at 40 C, dry heat at 70 C, 65% and
100% relative humidity at room temperature; and salt spray and seawater environments at room
temperature. The results of this study indicate that the flexural strength and stiffness; and the
fracture resistance of the tested GFRP composite do not show significant degradation due to prior
exposure to the environments investigated for up to 3000 hours. The flexural ductility is shown to
degrade after exposure in high humidity environment.
Study on the Reactivity Activation of Steel Slag through Autoclaving Curing
Authors: Lin Yong Quan , Wen Zi Yun , Yang Yong Min , Yang Yi Bo , Lin Dong
Published: March 2009

Feasibility study of partially replacement of cement and ground sand by ground steel slag (GSS)
and ground granulated blast furnace slag (GGBFS) in producing prestressed high strength concrete
pile (PHC) was conducted. The results showed that under normal curing（20oC, 95% RH）and the
steam curing condition (80oC), GSS possessed less reactivity than GGBFS. However, under
autoclave curing condition (180 °C, 1.0MPa), the reactivity of GSS can be effectively activated. The
autoclaving strength of the concrete made from 20% GSS with Blaine 550m2/kg, 55% cement and
25% ground sand could reach 89.0 MPa which is not only higher than that of GGBFS (82.8MPa),
but also higher than that of traditional PHC concrete (83.9Mpa, 70% cement and 30% ground sand).
It’s feasible to produce PHC concrete by GSS with high fineness and optimized dosage.