bluuebunny/crossref_metadata_2025 huggingface dataset:
A Preliminary Model Accounting for the Suction Pressure in CMP Process
Authors: Zhang Chao Hui , Luo Jian Bin , Chang Qiu Ying
Published: March 2009

Chemical mechanical polishing (CMP) is a widely used technique to achieve high level of
global and local planarity required in modern integrate circuit (IC) industries and hard disk
manufacturing process, etc., which pleas for concentrate researches. The main purpose of the present
research is in an attempt to express the counterintuitive experimental aftermath: the ‘negative’
pressure, i.e., a suction force occurred in conventional commercial CMP process. A preliminary two
tiers wafer-scale flow model for CMP is presented considering the roughness as well as the elasticity
of the bulk pad substrate. Numerical simulations were conducted to elucidate the contact pressure and
flow pressure distributions. The results show that a divergence region appears near the leading edge,
which contributes to the suction pressure. A stress-richened area near the edges will give rise to over
polishing. The research aftermaths agree well with the experiments, that validate the proposed
analysis to some extend. This will shed lights on the mechanism of CMP process, which for a long
time is considered as a black art where empirical or semi-empirical data are dependent upon to
optimize the CMP parameters.
Reciprocating Triboligical Behavior of PA1010 Filled with ZnOw
Authors: Wang Shi Bo , Ge Shi Rong
Published: March 2009

The friction and wear behavior of nylon1010 composites filled with different
proportions of ZnOw in reciprocating sliding against GCr15 steel ball under dry friction condition
were studied. The worn surface and wear particles were then examined with SEM. The elastic
modulus, nano-hardness and ball indentation hardness of composites increased with the content of
ZnOw. The coefficients of friction of composites decreased lightly, which changed from 0.36 and
0.26 of nylon matrix to 0.30 and 0.22 of composites at 0.04 m/s and 0.08m/s sliding velocity,
respectively. The anti-wear property of composites was improved with large extent. The typical
wear mechanism of nylon matrix is adhesion and micro-melting. However, peeling of surface layer
appears owing to fatigue for composites. Roll-shaped wear debris were produced for pure nylon,
while flake-like debris for nylon composites.
A Study on Diffusion Wear of Machining Tool and Simulation by Diffusion Couple
Authors: Ngai Tungwai Leo , Zhang Da Tong , Li Yuan Yuan
Published: March 2009

By choosing appropriate annealing temperature and annealing time, diffusion couples
made of aluminum bronze and tool materials were prepared to simulate the diffusion and phase
formation during the actual machining. These results were compared to those obtained from turning
experiments. In agreement with results obtained from diffusion couple experiments, all turning
experiments showed that major elements in both tool materials and workpiece diffused into their
counterparts. The diffusion of C away from the tool will reduce the tool strength. It is helpful to use
diffusion couple results to comprehend the diffusion effect in the actual turning process.
Microstructure and Wear Behavior of Thermally Sprayed Fe-Based Amorphous Coating
Authors: Kim Yeong Sik , Kim Kyun Tak , Kim Byung Tak , Bae Jong Il
Published: March 2009

In this study, microstructure and wear behavior of thermally sprayed Fe-based alloy
coatings were investigated. Fe-based alloy coatings were formed on a carbon steel substrate and then
heat-treated at temperature of 700 oC for 20 minutes. Dry sliding wear tests were performed using the
sliding speeds of 0.4 and 0.8 m/s, the applied loads of 3 and 6 N. Microstructure and wear behavior of
as-sprayed and heat-treated Fe-based amorphous coatings were studied using a scanning electron
microscope(SEM), transmission electron microscopy(TEM) and X-ray diffraction(XRD).
Digital Image Based Modeling of Rock Failure at Meso-Scale
Authors: Yu Qing Lei , Tang Chun An , Liang Zheng Zhao , Tang Shi Bin
Published: March 2009

This paper presents a new meso-mechanical analysis method of rock failure. The actual
inhomogeneity of rock at meso-scale level is represented by processing the image of rock section
and incorporated into Realistic Failure Process Analysis code (abbreviated as RFPA2D). Here, this
numerical tool is employed to study the fracture phenomena of granite sample considering the
interface strength between mineral grains. Numerical results show that interface strength has
significant influence on the strength of sample and its failure mode. The larger the interface strength
is, the more brittle rock samples become and the strength is bigger. With the interface strength
increasing, failure mode gradually varies from intergranular frature to transgranular fracture.
Stress Intensity Determination for MSD Riveted Stiffened Panels in the Presence of Corrosion
Authors: Yu Da Zhao , Chen Yue Liang , Jin Ping
Published: March 2009

Accurate stress intensity solutions for multiple site damage (MSD) cracks in riveted
stiffened panels are difficult to determine due to geometric complexity along with variations in rivet
load transfer and corrosion, especially the interaction of MSD cracks. A methodology was proposed
for efficiently depicting rivet in stiffened panel using finite elements. Rivet material properties were
determined based on an empirical force-displacement relationship, for highly refined rivet model as
well as for idealized spring element representations of rivets. Parametric studies of panels with a
middle crack and a central stiffener indicate that rivets can provide comparable load transfer and
relative displacement if the rivets closed to the crack are explicit modeled. Using idealized
combination of explicitly and spring element representations of rivets, the stress intensity factors
(SIFs) for uncorroded and corroded one-bay stiffened panels were predicted. The results show that the
effect of MSD and thinning of the sheet is to increase substantially SIFs values compare to that of a
single crack without corrosion. But the SIF is insensitive to corrosion of stiffener. The particular rivet
material has relatively little effect on SIF values, while the rivet diameter has a significant effect.
Numerical Simulation on AE Characteristics of Rock and Concrete Materials
Authors: Kang Yu Mei , Tang Chun An , Liang Zheng Zhao , Chen Gen Gye
Published: March 2009

Based on physical model of three-point-bending test, the AE characteristics of
three-point-bending beams with different relative notch depth during the entire loading period was
simulated by using RFPA3D(realistic failure process analysis) code. Simulation results show that the
relative notch depth affects the AE characteristics significantly. With increasing relative notch depth,
the occurrence of AE events decreases remarkably. The stress distribution figures, elastic modulus
photo and AE relative energy time-space distribution figures as well as an analysis on the failure
process are also provided. Based on the analysis of simulation results, it is concluded that the
heterogeneity of rock and concrete has great influence on the crack propagation path, which leads the
crack propagation path becoming curvilinear.
Hydrodynamic Analysis of Circular Translational Polishing under Mixed Lubrication
Authors: Zhai Wen Jie , Liu Chang Xiong , Feng Pei Lian
Published: March 2009

The average Reynolds equation and average clearance equation of circular translational polishing (CTP) under the quasi-stable mixed lubrication state are set up in polar coordinates. The distributions of fluid pressure and contact pressure during polishing are numerically analyzed by solving simultaneously these equations along with the contact pressure equation. The effects of various process parameters on hydrodynamic performance of CTP are analyzed. By comparing the distributions of periodic average pressure along radial direction under fully and partially lubricated states, we conclude that carefully controlled CTP under mixed lubrication is beneficial to improving the surface quality and planarity of the wafer.
Experimental Study on Lapping Force Characteristics of Hard-Brittle Materials in Ultrasonic Vibration Lapping
Authors: Zhang Chang Juan , Liu Chuan Shao , Zhao Bo , Jiang Wu Ji
Published: March 2009

Hard-brittle materials have been popular used in manufacture experience because of their excellent performances. However the low plasticity, frangibility and non-conduction make the machining very difficult, especially in ultra-precise surface fabrication. Therefore, ultrasonic vibration is introduced to conventional lapping for the purpose of proper lapping force, higher removal rate and fine surface quality. Through conventional and ultrasonic lapping experiment of hard-brittle materials with different lapping parameters and different vibration models, the empirical formula of lapping force in ultrasonic lapping is deduced by orthogonal regression analysis, the optimum lapping parameters are put forward and the primary and secondary influencing sequence of parameters on lapping force is presented. Moreover, the influencing rule of different lapping parameters such as rotational speed, feed speed, oilstone grit and lapping depth etc. on lapping force is carried out. Experimental results show that ultrasonic vibration lapping is a high efficient processing method adapting to hard-brittle materials.
Experimental Investigation of Intermittent Rotary Ultrasonic Machining
Authors: Zeng Wei Min , Li Zhi Chao , Xu Xi Peng , Pei Zhi Jian , Liu Ju Dong , Pi Jun
Published: March 2009

Rotary ultrasonic machining (RUM) is considered as an effective machining method,
which has been utilized to machine hard and brittle materials such as advanced ceramics. In order to
improve the hole wall surface quality during RUM, it is important to wash away swarf in the gap
between the tool and the workpiece as fast as possible. In this paper, a new machine process –
intermittent rotary ultrasonic machining (IRUM) – is introduced for the first time. The cutting force,
surface roughness and coolant flow rate in conventional rotary ultrasonic machining (CRUM)
process and IRUM process are compared. It is found that compared with CRUM, the output coolant
flow rate could be increased significantly by using the IRUM method. It is also found that the
surface roughness of workpiece can be improved significantly in IRUM.
The Modeling and Finite Elements Simulation for Pressure Field of Abrasive Jet Precision Finishing With Grinding Wheel as Restraint
Authors: Yuan Suo Xian , Liu Xi Ying , Cai Guang Qi , Shao Jin Ping
Published: March 2009

It is innovative to combine abrasive jet machining and conventional grinding together in
this thesis. And it realizes a new sort of grinding wheel restricted with abrasive jet processing. The
three-dimensional mathematical model of hydrodynamic pressure of wedge-like grinding zone
between grinding wheel and workpiece on abrasive jet finishing with wheel as restraint was
established, and the finite elements simulation analysis for the hydrodynamic pressure was
implemented. This paper investigated the liquid hydrodynamic pressure, the regularities of
distributing of velocity, influencing factors and the affection for processing technique.
Analysis and Simulation of Grinding Wheel Surface Topography
Authors: Lin Bin , Huang Xin Yan
Published: March 2009

The topography of the grinding wheel has a profound effect in analysis and predicting the finished surface roughness. In this paper, the statistical analysis is applied to establish a distribution function of the grain protrusion heights, and the 3-D simulating topography of grinding wheel will be identified. Through experiments, the generated grinding wheel topography is effective in predicting the finished surface roughness.
A High-Speed Nickel Plating Bath for Manufacture of Diamond Tools
Authors: Pan Bing Suo , Yang Yang
Published: March 2009

To increase the manufacture efficiency of electroplated diamond tools, a nickel plating
solution containing ammonium sulphate and sodium formate was investigated. The effects of
concentration of ammonium sulphate, sodium formate and pH value on throwing power, covering
power, ability to resist Cu2+ contamination and deposit microhardness were studied. Surface
topography of deposits was also observed by SEM. Compared to watts bath, the plating solution
studied is advantageous in terms of the performance of plating solution, deposit hardness and
diamond bit behavior. Ammonium sulphate can refine deposit crystal grains and result in crystal
form change.
EP4 Agonist Accelerates Osteoinduction and Degradation of β-Tricalcium Phosphate in Canine Model
Authors: Nasu Tomonori , Takemoto Mitsuru , Fujibayashi Shunsuke , Neo Masashi , Akiyama Norihiro , Nakamura Takashi
Published: March 2009

Several kinds of biomaterials are known to possess osteoinductive ability without bone
inductive substances in ectopic implantation. β-TCP is one such material that has been reported to
exhibit this ability in a canine model. In addition, prostaglandin E2 has been proved to accelerate
osteogenesis in a rodent model, and one of its receptors EP4 has been considered to play a
particularly important role. We examined that the EP4 agonist accelerates β-TCP-induced
osteoinduction in a canine model. The results suggested that the EP4 agonist accelerated not only
osteoinduction but also osteoclastogenesis prior to bone formation.
Investigation of Multiwall Carbon Nanotube Modified Hydroxyapatite on Human Osteoblast Cell Line Using iTRAQ Proteomics Technology
Authors: Xu J.L. , Khor Khiam Aik , Sui J.J. , Chen W.N.
Published: March 2009

Hydroxyapatite (HA) is a bioactive ceramic material with a chemical composition
similar to natural bone, and carbon nano tubes (CNT) is able to enhance the brittle ceramic matrix
without detrimental to the bioactivity. This study reported an attempt to use a commercially
multiwalled CNT strengthen brittle hydroxyapatite bioceramics. Using iTRAQ-coupled 2D LCMS/
MS analysis, we report the first study of protein profile in osteoblasts from human osteoblastic
cell line incubated separately on HA with and without strengthening multiwall CNT surfaces. Sixty
proteins were identified and quantified simultaneously at the initial culturing stage of 3 days. The
results were validated by Western blotting for selected proteins: Fetuin-A, Elongation factor II and
Peroxiredoxin VI. Fetuin-A showed up-regulation, and Peroxiredoxin VI gave down-regulation in
the osteoblasts cultured on HA based ceramic surfaces. Similar regulation was expressed by the
protein of Elongation factor II on the phase pure HA surfaces as compared to the control group
cultured on the polystyrene substrate. Relatively high EF 2 expression was detected on the phase the
surfaces of CNT strengthen HA samples.
Regulation of Osteoblast-Like Cell Behaviors on Hydroxyapatite by Electrical Polarization
Authors: Nakamura Miho , Nagai Akiko , Ohashi Natalie , Tanaka Yumi , Sekijima Yasutaka , Nakamura Satoshi , Yamashita Kimihiro
Published: March 2009

The osteoblast adhesion to the substrates are recognized to play a fundamental role in osteoconduction process. The purpose of this study was to evaluate the in vitro behavior of osteoblasts cultured on polarized hydroxyapatite (HA), having the enhanced osteobonding abilities. Osteoblast-like cells were seeded onto the polarized HA and investigated the adhesion and motility. The polarization had no effects on the percentage of the number of the spreaded cells against all the adhered cells, but had significant effects on the elongation of adhered cells from fluorescent observation and on the cell motility showed by the wound healing assay. The charges induced on the HA surface accelerated the cytoskeleton reorganization of the adhered cells cultured on HA specimens. The acceleration was emerged as the cells shape, actin filament pattern such as stress fiber formation, and the prolongation of the cell movement distances.
Reconstruction of Liver Organoid Using an Apatite-Fiber Scaffold, a Radial-Flow Bioreactor and FCL-4 Cells of Hepatocyte Model
Authors: Aizawa Mamoru , Hiramoto A. , Maehashi H. , Matsuura Tomokazu
Published: March 2009

We have previously developed apatite-fiber scaffolds (AFSs) for bone tissue engineering
using single-crystal apatite fibers and carbon beads. In the present investigation, we examined the
possibility of reconstruction of a liver organoid via three-dimensional (3D) culture of hepatocytes
using the AFSs and the radial-flow bioreactor (RFB), aiming to apply the scaffold as a matrix for
regeneration of a real organ. FLC-4 cells were used as a model of hepatocyte. The cells were
well-viable in the RFB settled with AFSs over a period for 28 d, compared with the cases of
cellulose beads and apatite beads with high porosity of 85%. We conclude that the present AFS
may be a promising scaffold for tissue engineering of liver.
Stimulatory Effect of Nano-Sized Calcium Metaphosphate Particles on Proliferation and Osteoblastic Differentiation of Human Bone Marrow Mesenchymal Stem Cells
Authors: Lee Sun Young , Son Min Jung , Khang Gil Son , Son Young Suk , You Chang Kuk , Kim Suk Young , Shin Hong In , Park Eui Kyun , Kim Shin Yoon
Published: March 2009

Recently, nanomaterials have received considerable attention because of their potential
applications in the biomedical field. In the present study, we investigated the effects of nano-sized
calcium metaphosphate (CMP) particles (50 nm) compared with micro-sized CMP particles (200-500
nm and 10 μm) on the proliferation and osteoblastic differentiation of human bone marrow stem cells
(BMSCs). BMSCs were challenged with CMP particles with different sizes for 3, 5, and 7 days. An
analysis of the proliferation revealed that the nano-sized CMP particles (50 nm) stimulated the
proliferation of BMSCs up to 27.79% compared to the untreated control. This stimulatory effect of
the nano-sized CMP particle was dose-dependent. CMP particles appeared to adhere on the surface of
BMSCs but this did not cause distinguishable morphological changes. Moreover, all CMP particles
(50 nm to 10 μm) were capable of stimulating an osteoblastic differentiation of BMSCs as accessed
by alkaline phosphatase (ALP) and von Kossa stainings. Further molecular analysis revealed that all
the CMP particles induced an expression of osteoblast-related genes such as osteocalcin (OC) and
collagen I (Col I). Taken together, our data demonstrate that nano-sized CMP particles have the
potential to stimulate the proliferation and osteoblastic differentiation of BMSCs.
Total Knee Replacement for Rheumatoid Arthritis by Using Improved Cement Technique by Interposing Hydroxyapatite Granules
Authors: Kim Sok Chol , Oonishi Hironobu , Oonishi Jr. Hiroyuki , Ohashi Hirotsugu
Published: March 2009

Improved cement technique by interposing less than two layers of hydroxyapatite
(HA) granules between bone and bone cement at the cementing (Interface Bioactive Bone
Cement : IBBC) have been performed in total knee replacement (TKR). Results of TKRs of
the rheumatoid arthritis (RA) who used IBBC were evaluated. 54 knees of the RA could be
followed up clinically and radiologically. As a control, clinical results of TKR with
conventional cementing (Non-IBBC) were used. In IBBC cases, the appearance rate of the
radiolucent lines on the tibial components and the periprosthetic osteolysis of the tibial
components were significantly low. In IBBC, bone cement bound to HA mechanically
immediately after surgery and HA granules bound to the bone physicochemically after bone
ingrowth into the spaces around the HA granules. Thus, we believe that IBBC is a method
combining the advantage of cementless HA coating and bone cement.
Influence of Ca2P2O7 on Sintering Ability, Mechanical Strength and Degradability of β-Ca3(PO4)2 Bioceramics
Authors: Lin Kai Li , Chen Lei , Chang Jiang , Lu Jian Xi
Published: March 2009

In the present study, Ca2P2O7-doped β-Ca3(PO4)2 bioceramics were fabricated by
pressureless sintering process. The effect of Ca2P2O7 on the sintering ability, mechanical strength
and degradability of the ceramics were investigated. The results showed that the Ca2P2O7 could
apparently decrease the sintering ability and mechanical properties of β-Ca3(PO4)2. Moreover, the
relative density and mechanical strength of the sintered samples decreased gradually with the
increase of the Ca2P2O7 additive amount. However, the dissolution rate of the samples increased
with the increase of the Ca2P2O7 additive amount.
Apatite Forming Ability of Bulk Metallic Glass Surface via Hydrothermal Treatment
Authors: Onoki Takamasa , Wang Xin Min , Zhu Sheng Li , Hoshikawa Yasuto , Sugiyama Naota , Akao Masaru , Yasuda Eiichi , Yoshimura Masahiro , Inoue Akihisa
Published: March 2009

Apatite forming and bonding ability of Ti based bulk metallic glass
((Ti0.40Zr0.10Cu0.36Pd0.14)99Ca1: BMG) were investigated as a new type of biomaterials. Powder
mixture of CaHPO4･2H2O and Ca(OH)2 and the BMG disks were treated with autoclave for
hydrothermal hot-pressing simultaneously (150°C, 40MPa). And then the BMG disks were soaked
in simulated body fluid (SBF, Kokubo solution). Apatite were deposited and covered on the
surface of the BMG. It was firstly demonstrated that surface of Ti based bulk metallic glass could
be revealed apatite forming ability.
Tailoring Mechanical Behavior of PVA-Bioactive Glass Hybrid Foams
Authors: Costa Hermes S. , de Oliveira Agda Aline Rocha , Oréfice R.L. , Mansur Herman S. , Pereira Marivalda
Published: March 2009

Porous scaffolds have been developed in many forms and materials, but few have
reached the combination of adequate physical, biological and mechanical properties. In previous
works hybrid foams bioactive glass polyvinyl alcohol (PVA) were prepared by the sol-gel process
for application as scaffold for bone tissue engineering. We observed that synthesis parameters such
as PVA hydrolysis grade, PVA solution concentration, and PVA content in the hybrids affected
both synthesis results and structural characteristics of the obtained foams. A marked change in
foaming behavior occurs for PVA contents around 60%. In this work we analyze the effect of
different compositions and synthesis parameters on the mechanical behavior of PVA-bioative glass
foams. The compression tests showed that an increase of PVA fraction changes the mechanical
behavior due to different mechanisms leading to cell collapse. For hybrids with lower PVA contents
(20 to 30%) the cell collapse is due to brittle crushing. For intermediate polymer content (40-60%)
the contribution of plastic yielding in the plateau region increases and it becomes the predominant
mechanism of cell collapse for samples with higher polymer content (70-80%).
The Effect of Reaction Conditions on Hydroxyapatite Particle Morphology and Applications to the Reticulated Foam Method of Scaffold Production
Authors: Robinson J.H. , Best Serena , Ahmad Z. , Edirisinghe Mohan J.
Published: March 2009

The production of nano-scale hydroxyapatite (HA) suspensions to be used for the
reticulated foam method of scaffold production was investigated at temperatures of between 10 and
60OC. An increase in reaction temperature was associated with an increase in the particle size and
some decrease in the aspect ratio of the particles. Pre-treatment of the polyurethane foam template
using PPDS (potassium peroxodisulfate) solution resulted in a significantly improved coating of
HA when compared to the untreated samples or those treated with ethanol. Initial trials coating the
polyurethane with HA produced at the different reaction temperatures showed a superior coating
with the suspension produced at 10OC compared to that at 60OC. A scaffold was produced using the
HA suspension produced at room temperature, but further understanding of the suspension
properties and the optimum conditions for coating of the PU foam are required for improved
mechanical performance.
Injectable Bone Cements for Vertebroplasty Studied in Sheep Vertebrae with Electron Microscopy
Authors: Jarmar Tobias , Uhlin Thomas , Höglund Urban , Thomsen Peter , Hermansson Leif , Engqvist Hakan
Published: March 2009

Vertebral compression fractures were simulated by making a hole into sheep vertebrae
and by injecting a stabilizing material. The injectable bio-ceramic Xeraspine™ was evaluated
together with a commercially available PMMA (Vertebroplastic™) as the reference material. The
Vertebrae were harvested after 7 days and prepared for microscopy. The samples were deposited
with gold on the surface and thereafter subjected to SEM and EDX analysis. It was found that the
Xeraspine-bone interface was composed of a mixture of elements. The Vertebroplastic implant was
embedded in a carbon containing tissue, likely a soft tissue capsule. The Xeraspine sample was
subjected to high resolution analysis in the TEM combined with EDX measurements. The TEM
sample was prepared with a novel technique for preparation of the tissue-material interface (FIB). In
the TEM analysis it was found that the interface region consists of ZrO2 together with a mixture
possibly consisting of katoite and apatite formed during setting and/or originating from the boneapatite.
Radiopaque Strategy for Bone Injectable Substitute
Authors: Baroth Serge , Bourges Xavier , Fellah Borhane H. , Daculsi G.
Published: March 2009

The purpose of this study ass to investigate the addition of round 80-200m granules
shape radiopaque agents (RA) to synthetic Injectable Bone Substitute to improve contrast
performance for minimal invasive surgery MIS. Composites were obtained by mixing BaSO4, Bi2O3,
Lu2O3 or GdPO4 with calcium deficient apatite CDA which decompose during sintering process in
BCP (60% HA, 40% β-TCP). Each composite was characterized: by XRD, FTIR. Biocompatibility
was tested in vitro and in vivo in bony site (3 weeks implantation in rats). Primary results show that
the suitable radiopaque BCP/RA composite (radiopacity intensity, biological responses) appeared to
be BCP/Ba. Next works will complete the current studies on biological performance in association
with different kind of resorbable injectable bone substitute as suspension, gel or calcium phosphate
cements.
Development of In Situ-Formed Interconnected Porous Scaffolds with Low Porosity
Authors: Li Yu Lin , Kikuchi Masanori
Published: March 2009

Biocompatible and water-soluble fibers (sodium carboxymethyl cellulose (CMC)) were
fabricated via a wet-spinning method. The CMC fibers/ polymethyl methacrylate (PMMA)
mixtures and CMC fibers/Poly (L-lactide-co-glycolide-co- -caprolactone) (PLGC) mixtures were
prepared by a heat-kneading method. For CMC fibers/PMMA, after removal of the CMC fibers
from the mixtures, the interconnected porous scaffolds with porosity from 27.79 % to 60.98 %
(volume percent) were obtained. For CMC fibers/PLGC, the interconnected porous scaffolds with
porosity 38.55 % and 76.83 % (volume percent) were prepared. The solid CMC fibers/PLGC
mixtures had the higher ultimate tensile strength and Young, s modulus than those of porous
PLGC scaffolds.
Porous Hydroxyapatite Surface-Modified by Polypyrrole-Heparin Conducting Polymer
Authors: Panero Stefania , Moreno Judith Serra , Aleandri Paolo , Landi Elena , Sprio Simone , Tampieri Anna
Published: March 2009

The preparation and characterization of an inorganic/organic composite scaffold is proposed in
this paper. The substrate was realized by the polymerization of an electroconductive polymer, namely
polypyrrole PPy, into an hydroxyapatite HAp porous support. The PPy/HAp composite was characterized by
XRD, Hg porosimetry measurements, SEM-EDS and electrochemical test. The results pointed out that the
PPy polymer entered into the HAp whole pores moving through the interconnected paths of the
hydroxyapatite matrix. The PPy thin film doped with heparin maintained its electrochemical characteristics
even in the ceramic support.
PL DLLA Calcium Phosphate Composite Combined with MBCP Gel® for New Surgical Technologies: Resorbable Osteosynthesis and Bone Substitute
Authors: Jouan Gaelle , Goyenvalle Eric , Aguado Eric , Cognet Ronan , Moreau Françoise , Bourges Xavier , Daculsi G.
Published: March 2009

We have performed and evaluated a composite combining PL DLLA and PCa able to
have a better control of the hydrolysis and maintain of the mechanical property on time, until
wound healing was achieved. Bioabsorbable osteoconductive composite is devoted to the
development of resorbable osteosynthesis for spine and osteoarticular surgeries. Such resorbable
osteosynthesis will be associated to new bone substitute having high osteogenic property but
without initial mechanical property. The purpose of this study was to evaluate the resorption kinetic
of a composite using PL DLLA (Poly [L-Lactide-co-D,L-Lactide] acide) charged with PCa granules
and the interaction with injectable bioceramic without self hardening. MBCP gel® is a composite
associating a mineral phase of an intimate nanoscale melting of hydroxyapatite and beta tri calcium
phosphate and an aqueous phase containing a synthetic polymer derived from cellulose HPMC
(hydroxyl propyl methyl cellulose).
Surface Functionalization of Biomaterials with Alkaline Phosphatase
Authors: Verné Enrica , Ferraris Sara , Vitale-Brovarone Chiara , Spriano Silvia , Bianchi Claudia Letizia , Morra Marco , Cassinelli Clara
Published: March 2009

Two different glasses, one biocompatible but with a low bioactivity index (G1) and the other with an higher bioactivity index (G2), the ceramic version of the second glass and a titanium alloy (Ti6Al4V) have been functionalizated by anchoring alkaline phosphatase (ALP) on their surfaces. The enzyme has been chosen because it is involved in mineralization processes of hard tissues and is a model for more complex ones. ALP has been grafted on glasses and glass-ceramics surfaces both with and without samples silanization and on metallic surfaces with and without tresyl chloride activation. Samples have been analyzed at each step of the functionalization process in order to verify it.
Electrosprayed Nanoapatite: A New Generation of Bioactive Material
Authors: Thian E.S. , Ahmad Z. , Huang Jie , Edirisinghe Mohan J. , Jayasinghe S.N. , Ireland D.C. , Brooks Roger A. , Rushton Neil , Bonfield William , Best Serena
Published: March 2009

Fine nanoapatite relics were deposited on glass substrates by electrohydrodynamic atomisation, using nanohydroxyapatite (nHA), nano-carbonated hydroxyapatite (nCHA) and nanosilicon- substituted hydroxyapatite (nSiHA) suspensions. These electrosprayed nanoapatites were evaluated in-vitro using simulated body fluid (SBF) and human osteoblast (HOB) cells. The SBF study revealed that newly-formed apatite layers were observed on the surface of the relics. Furthermore, enhanced HOB cell growth was observed on each of the nanoapatites at all time points. Hence, this work demonstrated that electrosprayed nanoapatites offer considerable potential as biomaterials.
Chemically Pre-Treated and Biomimetically Coated Titanium for Medical Applications: The True Structure Revealed by Transmission Electron Microscopy
Authors: Conforto Egle , Müller Frank A. , Müller Lenka , Caillard Daniel
Published: March 2009

Scanning (SEM) and cross-sectional transmission (TEM) electron microscopy analyses
have been performed to study the transformations induced on the surface of titanium implants by a
sequence of chemical treatments having as goal to induce the nucleation and growth of hydroxycarbonated
apatite (HCA). In the first step, an acid etching forms a rough titanium hydride layer,
which remains unchanged after subsequent treatments. In a second step, soaking in a NaOH
solution induces the growth of nanobelt tangles of nanocrystallized, monoclinic sodium titanate. In
a third step, soaking in a simulated body fluid transforms sodium titanate into calcium and
phosphorus titanate, by ion exchange in the monoclinic structure. Then, HCA grows and embodies
the tangled structure. The interfaces between the different layers are shown to be strong enough to
prevent from interfacial decohesion. The role of the titanate structure in the nucleation of HCA is
finally discussed.
In Vitro Behavior of Two Distinct Titanium Surfaces Obtained by Anodic Oxidation
Authors: Santos Emanuel , Kuromoto Neide K. , Campos Doris M. , Mazzaro Irineu , de Almeida Soares Gloria Dulce
Published: March 2009

Two different Ti oxide films produced by anodic oxidation were submitted to in vitro
bioactivity and cell culture tests. The oxide films were produced in 1.0M H2SO4/150V and
1.0M Na2SO4/100V. Surfaces were found to be homogeneous and rough, with the presence of
pores. Both oxide films presented anatase and rutile phases. Ti oxide film produced in Na2SO4 was
rougher than the film grown with H2SO4 and composed of a rutile-rich phase. Both films were
constituted by TiO2 and Ti2O3 oxides. Despite the differences observed, after 7 days, a calcium
phosphate layer was precipitated on both surfaces. Indeed, these two treatment conditions seem to
be efficient to spread and attach osteoblast-like cells within 4h.
Microstructure and Bonding Feature of the Bioceramic Composite Coating Obtained by Nd: YAG Laser Cladding
Authors: Wang Ying Chun , Li Yan Min , Xu Zhen Min , Deng Qi Lin , Li Jian Guo , Zhou Yao He
Published: March 2009

Undesirable phase and microstructure formation, and poor HAP/metal bonding strength
restrict the fabrication technique to obtain HAP and other calcium phosphate ceramic coatings. In this
paper a bioceramic composite coating, which includes HAP andβ-Ca2P2O7, was obtained by laser
cladding with pre-depositing mixed powders of CaHPO4·2H2O and CaCO3 directly on the 316L
stainless steel metal substrate. The phases, microstructure and bonding feature of the bioceramic
composite coating are characterized by X-ray diffraction(XRD), scanning electron
microscopy-energy dispersive spectroscopy(SEM-EDS). The microstructure of the coating consists
of minute granular HAP that is distributed among the overlapped club-shapedβ-Ca2P2O7. Uniform
presences of Ca, P and O in bioceramic composite coating supplie necessary elements for the
synthesis of HAP andβ-Ca2P2O7. Diffusions inwards of P and O into alloying layer help form the
chemical metallurgical bonding and composition gradient distributions are present. a chemical
metallurgical bonding was formed between the bioceramic composite coating and metal substrate.
Three Dimensional Mapping of Texture in Dental Enamel
Authors: Al-Jawad M. , Simmons L.M. , Steuwer Axel , Kilcoyne S.H. , Shore R.C. , Cywinski R. , Wood David J.
Published: March 2009

We have used synchrotron x-ray diffraction to study the crystal orientation in human
dental enamel as a function of position within intact tooth sections. Keeping tooth sections intact
has allowed us to construct 2D and 3D spatial distribution maps of the magnitude and orientation of
texture in dental enamel. We have found that the enamel crystallites are most highly aligned at the
expected occlusal points for a maxillary first premolar, and that the texture direction varies spatially
in a three dimensional curling arrangement. Our results provide a model for texture in enamel which
can aid researchers in developing dental composite materials for fillings and crowns with optimal
characteristics for longevity, and will guide clinicians to the best method for drilling into enamel, in
order to minimize weakening of remaining tooth structure, during dental restoration procedures.
Biomineralization Studies in Age Induced Human Teeth
Authors: Sridhar T.M. , Kishen A. , Shanmugaraj S. , Praveen R. , Srinivas S.K. , Das D. , Subbiya A.
Published: March 2009

Human teeth has “structure” and yet is mostly treated as material. Differentiation
between material and structure is crucial to understand complex biological material such as human
dentine. The aim of the present work is to determine the bioceramic gradient phases of the crystal
structure of the teeth across the crown and root region with age. Around 50 samples of teeth of
different age groups were collected, decontaminated and sintered at 400, 600 and 800°C. After
removal of the enamel the root and crown regions were machined and characterized for their
vibrational states by FTIR investigations. The studies indicate the presence of hydroxyapatite as the
major phase after sintering along with the typical hydroxyl peaks. A weight loss ranging from
7 - 42 % after sintering at 400 and 800°C respectively was observed across the different age groups.
A through analysis would provide us an understanding in studying the desired nature of the teeth
and kinetics of tooth mineralization.
Monitoring of Blood Flow by Drug Stimulation on Mouse Brain Using Non-Invasive Photoacoustic Imaging Technology
Authors: Yang Shi Hua , Lao Ye Qi
Published: March 2009

The highlight of photoacosutic imaging (PAI) is a method that combines ultrasonic resolution with high contrast due to light absorption. Photoacoustic signals carry the information of the light absorption distribution of biological tissue, which is often related to its character of structure, physiological and pathological changes because of different physiology conditions in response to different light absorption coefficients. A non-invasive PAI system was developed and successfully acquired in vivo images of mouse brain. Based on the intrinsic PA signals from the brain, the vascular network and the detailed structures of the mouse cerebral cortex were clearly visualized. The ability of PAI monitoring of cerebral hemodynamics was also demonstrated by mapping of the mouse superficial cortex with and without drug stimulation. The extracted PA signals intensity profiles obviously testified that the cerebral blood flow (CBF) in the mouse brain was changed under the stimulation of acetazolamide (ACZ). The experimental results suggest that PAI can provide non-invasive images of blood flow changes, and has the potential for brain function detection.
Micromachining of an In-Fiber Extrinsic Fabry-Perot Interferometric (MEFPI) Sensor by Using a Femtosecond Laser
Authors: Rao Yun Jiang , Deng Ming , Zhu Tao , Tang Qing Tao , Cheng Guang Hua
Published: March 2009

This paper reports a novel micro extrinsic fiber-optic F-P interferometric (MEFPI) sensor
micromachined on a conventional optical fiber (Corning SMF-28) by using a near-infrared
femtosecond laser, for the first time to the best of our knowledge. The strain and temperature
characteristics of such a sensor were investigated and the experimental results show that the strain
and temperature sensitivities are 0.006nm/με and -0.0017nm/°C, respectively. This type of MEFPI
sensors has a number of advantages when compared with conventional EFPI sensors, such as easy
fabrication, high integration degree, good reliability, low temperature cross-sensitivity, low cost,
and capability for mass-production, offering great potential for a wide range of sensing applications.
Fabrication of Nanotemplate and Nanowires from Bulk Aluminum at Room Temperature
Authors: Chan Ching Yuen , Jin Bang Kun , Yung Kai Leung , Xu Yan
Published: March 2009

A method of fabricating nanotemplate and nanowires by the anodization of bulk aluminum at room temperature is reported in this paper. Details of manufacturing processes as well as some in-depth discussions on the formation mechanism of nano pores with reference to the phenomena observed in experiments are presented. Effects of fabricating conditions such as the anodization time, temperature, current intensity, voltage and features of solutions, were studied in the experiments.
Microlens Array Homogenizer for Laser Illuminated Projector
Authors: Chen Cheng Huan , Chen Chien Chuan , Yao Po Hung
Published: March 2009

Laser light source is a potential illumination light source for non-emissive display applications, especially for liquid crystal projection displays, due to its requirement of low etendue source and highly polarized light. In order to make a conversion from a circular Gaussian beam profile to a rectangular uniform distribution, a microlens array has been proposed as a homogenizer. The analytical and experimental results show that the microlens array with a pitch of 100um under laser beam illumination works as a diffractive element, and a promising uniformity can be obtained with a stack of two microlens array.
Waveguide Structure Design of Adiabatic Optical Directional Couplers Weighted by Sin-Square Function
Authors: Chen Chi Feng , Ku Yun Sheng , Chen Kuan Hsiung
Published: March 2009

This study discusses optimization of the adiabatic optical directional coupler (AODC)
based on sin-square weighting functions (SSF) for waveguide structure. The objective of the work
includes the define coupler of theory ranges, low crosstalk and short coupler length, respectively.
When the crosstalk is demanded to be smaller than -35 dB, the coupler length for SSF is 2 b0 λ
(minimum local beat length). Definitely SSF which is proposed can obtain a better result after the
structural design.
Barrel Chamber Polishing, Using Electrochemical Theories
Authors: Mahdavinejad Ramezan Ali
Published: March 2009

Electrochemical polishing is a well-known method in finishing of complex shapes
with high surface quality. Inner surface polishing of complex parts with high precision can
also be easily done by this method. In this research, barrel chamber’s surface, with numerous
serial surface angles, is analyzed so that, according to the various set ups, the optimized
polishing parameters are obtained. The comparison between electrochemical polishing and
conventional methods from this point of view, shows good advantages of this method, so that,
the machining time is more than thirty times less and produces very high surface quality.
Besides, the dimensional accuracy of the workpiece repeatability process in this polishing
method is noticeable.
Experimental Study of Microelectrode Array and Micro-Hole Array Fabricated by Ultrasonic Enhanced Micro-EDM
Authors: Zeng Wei Liang , Gong Yan Ping , Liu Ying , Wang Zhen Long
Published: March 2009

Micro electrical discharge machining (EDM), enhanced with ultrasonic vibration, is
explored and assessed as a method for developing microelectrode array, for microelectrode array
fabricated by LIGA has shortcomings such as complex technology and high price. Based on the
mechanism of micro-EDM, micro-hole array discharges to fabricate microelectrode array by reverse
copying. In the process of reverse copying, the thicker rod electrode can not rotate, resulting in
electric arc and short-circuit occurring easily, so it is necessary to add ultrasonic vibration on the
plane plate electrode, in order to exclude debris as soon as possible and stabilize machining process.
In the process of machining, four parameters, such as working voltage, working capacity, ultrasonic
amplitude and holes spacing, are important to machining efficiency, each parameter has four typical
values. In order to reduce experiment times, a scheme of orthogonal experiment was designed with
different parameters combination. With result of experiments, the ratio of mean square deviation to
error mean square deviation of each parameter was calculated and significance of each parameter
was obtained, and the best parameters combination was asserted through theoretical calculation.
Also, experimental study of using microelectrode array to machine micro-hole array by Micro-
EDM was made and influence curve of each parameter was drawn. Finally, 5×5 arrays of
microelectrode were obtained, the diameter of single electrode is less than about 30.m and heightto-
width aspect ratios is more than 8, moreover, these microelectrode arrays have good coaxiality
and surface quality.
Frequency Spectrum Features of Material Removal Function in Optical Manufacturing
Authors: Cheng Hao Bo , Zhi Jing Feng , To Suet , Wang Yong Tian
Published: March 2009

This paper proposes a novel wheel-shaped grinding/polishing tool, which is designed to
be controlled on both the self-rotation around its axis and the co-rotation around vertical axis Z at
the specified speeds respectively. Therefore, the surface material of the workpiece can be removed
by virtue of self-rotating motion. On the other hand, the co-rotating motion will also change the
manufacturing orbit continually. To analyze the characteristics of the tool, material removal in the
manufacturing zone on the workpiece surface is first established through theoretical modeling.
Subsequently, a good evaluating method, i.e. power spectral density, for analyzing the frequency
spectrum features of material removal function in computer-controlled optical grinding and
polishing is introduced in detail. By simulation, the power spectral density of the material removal
function was cut into several parts, some frequency with low amplifies of material removal function
were removed, and the modified material removal function reflected the actual processing status,
which was helpful in removing some residual high frequency errors on the surface of the workpiece.
Finally, the high amplitude such as at high frequency of 110mm-1 and 210mm-1 was reserved and
some other low amplitude frequencies were removed.
Microstructure Prediction of Hot-Deformed Aluminium Alloys
Authors: Donati Lorenzo , Dzwonczyk J.S. , Zhou Jie , Tomesani Luca
Published: March 2009

In this paper, a deformation test method to reproduce, on a laboratory scale, the
microstructure evolution of aluminium alloys occurring during industrial forming processes with a
limited number of tests is presented. A hot inverse extrusion setup was designed in order to
generate, inside one single specimen, a wide range of strains at a given temperature and ram speed.
Two commercial aluminium alloys (AA6060 and AA6082) were investigated at different processing
conditions (temperatures and forming rates). Detailed optical microstructures were examined and
grain sizes were determined at different spots of each specimen. Thermo-mechanical coupled
simulations of the deformation tests were performed using the DEFORM 3D FEM code. On the
basis of recrystallization equations, the distributions of strains, strain rates and temperatures were
correlated to the grain sizes measured through linear regression. Finally, FEM simulations were run
again with the established recrystallization model, and the results were compared with the
experimental data.
Numerical Simulation of Combined Forward-Backward Extrusion
Authors: Grizelj Branko , Plancak M. , Barisic Branimir
Published: March 2009

The paper analyses the process of simulation forward-backward extrusion. In metal forming industries, many products have to be formed in large numbers and with highly accurate dimensions. To save energy and material it is necessary to understand the behavior of material and to know the intermediate shapes of the formed parts and the mutual effects between tool and formed party during the forming process. These are normally based on numerical methods which take into account all physical conditions of the deformed material during the process. For this purpose, the finite element method has been developed in the past in different ways. The paper highlights the finite element simulation as a very useful technique in studying, where there is a generally close correlation in the load results obtained with finite elements method and those obtained experimentally.
Recent Developments in the Manufacture of Complex Components by Influencing the Material Flow during Extrusion
Authors: Ben Khalifa Nooman , Becker Dirk , Schikorra Marco , Tekkaya A. Erman
Published: March 2009

New innovative direct extrusion process variants, curved profile extrusion (CPE), twisted
profile extrusion (TPE), and hollow profile extrusion (HPE), which increase the flexibility of
aluminum profile manufacturing processes, are presented in this paper. These processes are
characterized by influencing the material flow inside the die so that the forming process is
completed when exiting the die. On the one hand, three-dimensionally curved profiles are produced
and analyzed by CPE regarding the accuracy, the influencing parameters, and the compensation
strategies. On the other hand, TPE and HPE make it possible to manufacture helical profiles usable,
for example, as screw rotors in fluid machinery.