bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Nano-Sized β-Tricalcium Phosphate on Remineralization in Glass Ionomer Dental Luting Cement
Authors: Hong Y.W. , Kim J.H. , Lee B.H. , Lee Yong Keun , Choi B.J. , Lee Jae Hoon , Choi H.J.
Published: March 2009

This study aimed to evaluate the anticariogenic and remineralization effects of the glass ionomer dental luting cement containing nano-β-TCP in vitro. The β-Tricalcium Phosphate (β-TCP) are the components of dental enamel and bone mineral as biological apatites. In addition, β-TCP contains a significant amount of calcium and phosphate, which can promote remineralization of enamel subsurface lesions in animal and human. RelyXTM glass ionomer cement(3M/ESPE, USA) was used as dental luting cement. Film thickness, setting time, and compressive strength was measured for each group of pure glass GIC, 15% nano-β-TCP GIC. Human molars were prepared in box-shaped cavities that were filled with the GIC with and without the 15% nano-β-TCP were placed in 25ml of pH 5.0 acid buffer for 4 days at 37°C. After 4 days, longitudinal sections (1007m) were obtained through the center of each restoration. The sections were analyzed using a scanning electronic microscope (SEM) and confocal laser scanning microscopy (CLSM) to identify the change in the enamel surface. A significant difference in the CLSM images between pure GIC and nano-β-TCP-GIC. CLSM allows the demineralized surface layers of sound enamel to be visualized down to approximately 100 μm. The pure GIC specimens had a relatively thick fluorescent layer. On the other hand, the fluorescent layer of the nano-β-TCP-GIC specimens were thinner. The SEM images of micro surfaces demonstrate that nano-β-TCP-GIC is less rough than pure GIC. Therefore, the addition of nano-β-TCP enhanced protection against acid demineralization and promoted remineralization of enamel surface.
Evaluation of Different Radiopacifiers for an MTA-Like Dental Cement
Authors: Coomaraswamy K.S. , Lumley P.J. , Shelton R.M. , Hofmann M.P.
Published: March 2009

The present study evaluated the influence of different radiopacifiers on an established
mineral trioxide aggregate (MTA)-like Portland cement system. Commercial MTA contains
bismuth oxide (Bi2O3) as the radiopacifier and inert alternatives tested were barium sulphate
(BaSO4), lanthanum oxide (La2O3) and tantalum pentoxide (Ta2O5). The radiopacity of the different
formulations was measured with densitometry, whilst relative porosity was determined using
helium pycnometry and compressive strength was measured as an indicator for the potential
longevity of the alternative cement formulations. At 20wt% radiopacifier content the order of
radiopacity was, Bi2O3 (3.71mm Aluminium equivalent), Ta2O5 (2.76mm Al), La2O3 (1.85mm Al)
and BaSO4 (1.48mm Al). The commercial MTA control had a radiopacity of 3.65mm Al. The
addition of all radiopacifiers caused a deterioration in strength and increased porosity; the
incorporation of 20wt% Bi2O3 reduced strength from 68MPa by 36%. Ta2O5-containing cement had
a strength comparable with that containing Bi2O3 (43MPa), whilst La2O3 and BaSO4 addition
generated even weaker cements. Commercial MTA had a similar strut density to the Bi2O3-
containing model system although had a lower strength (34MPa) due to its higher porosity. Bi2O3
appeared to be the best of the investigated radiopacifiers for this endodontic filling material as it
provided the highest mechanical stability, lowest porosity and was the most radiopaque.
Influence of Two-Step Sintering Variables on Phase Stability of Hydrothermally Prepared HAp Nano Powders
Authors: Ryu In Young , Kim Dae Joon , Han Jung Suk , Lee Myung Hyun
Published: March 2009

Two-step sintering was performed to prepare hydroxyapatite (HAp) with a high density
and a fine microstructure utilizing hydrothermally synthesized nano powders. Its effectiveness was
dependent on starting chemicals for precursors of HAp, powder processing condition, initial
temperature in the two-step sintering, heating rate to the initial temperature, and holding time at
final temperature. HAp powder, hydrothermally treated after aging of precipitate of Ca(OH)2 and
H3PO4 for 48 h, led to HAp having a high phase stability at elevated temperatures, a high density,
and a fine microstructure after two-step sintering with heating rate of 10°C/min to 1275°C.
Internal Diffusion of Micro/Nanoparticles Inside Body
Authors: Watari Fumio , Abe Shigeaki , Tamura Kazuchika , Uo Motohiro , Yokoyama Atsuro , Totsuka Yasunori
Published: March 2009

Both biochemical cell functional test and animal implantation test were done to investigate
the reaction to fine particles. Particles cause nonspecifically phagocytosis to cells and inflammation
to tissue for the size below 10m. With the size below 50nm particles may invade into the internal
body through the respiratory or digestive system and diffuse inside body. Ti mapping by XSAM after
the compulsory exposure test to the respiratory system showed the internal diffusion of 30nm TiO2
particles. They diffused with time course to lung, liver and spleen after injection from caudal vein.
Nanoparticles might be the objects whose existence has not been assumed by the biophylactic system.
Automatic Optical Inspection and Laser Cleaning of Image Sensors
Authors: Lee Jong Myoung , Cho Un Chung
Published: March 2009

A new dry cleaning methodology named laser shock cleaning and optical inspection
technique has been applied not only to remove the particles from the surfaces of image sensors but
also to inspect the surfaces automatically before or after the cleaning. In the packaging of CMOS
and CCD image sensing modules, the particles generated during the assembly process should be
removed from the surfaces of image sensors in order to ensure clear image as well as to enhance the
yield. The different kinds of particles were removed from the surfaces by the laser shock cleaning
technique which utilizes the airborne shock wave induced by intense laser pulse. For the
quantitative evaluation of cleaning performance, number, shape and size of the particles on the
surfaces of image sensors were measured by vision inspection technique before and after cleaning.
It was found that most particles on the surfaces were successfully removed after the treatment of
laser-induced shock waves. The average removal efficiency of the particles was over 95 %. It is
interestingly found that the remaining particles after the cleaning are based on organics, which are
probably attached during the bonding process.
A Study on the Grinding to Improve Profile Accuracy of Aspheric Lens
Authors: Baek Seung Yub , Lee Eun Sang , Won Jong Koo
Published: March 2009

This study presents the development of an ultra-precision grinding system based on a
new grinding technique called the “In-Process Grinding Method (IPGM)”. IPGM which is used for
grinding aspheric lens increases both the production and grinding performance, and significantly
decreases total production costs. To enhance the precision grinding productivity of ultra-precision
aspheric lens, we present here an ultra-precision grinding system and process for the aspheric
micro-lens. The tool path was calculated and CNC program generation and tool path compensation
were performed for aspheric lens. Using this ultra-precision grinding system, aspheric lens, 4mm in
diameter, were successfully performed. The profile error after the first grinding without any
compensation was less than 0.6μm, and surface roughness Ra was 0.01μm. In-process grinding was
performed with compensation. Results of the profile accuracy P-V 0.3μm and surface roughness Ra
0.006 μm were obtained.
Propagation Properties of Partially Polarized Gaussian Schell-Model Beams through an Aperture Lens with Spherical Aberration
Authors: Pan Liu Zhan , Ding Chao Liang , Yang Jie Hui , Yuan Xiao
Published: March 2009

Based on the beam coherence-polarization (BCP) matrix approach and propagation law
of partially coherent beams, the propagation properties of partially polarized Gaussian Schell-model
(PGSM) beams through an aperture lens with spherical aberration were studied. Our main attention
was focused on the effect of spherical aberration of the lens, partial coherence, aperture diffraction
and polarization on the behavior of the irradiance. The numerical calculation results are given to
illustrate how these parameters affect the focusing properties. A comparison with the previous
publications is also made, showing some extension has been made in our work.
Analysis on Anti-Vibration Characteristic of Synchronism Phase-Shifting
Authors: Wang Yi Min , Liu Xiao Jun
Published: March 2009

Vibration is the biggest problem for precise on-line surface measurement. In order to
investigate the possibility for phase-shifting interference technique to be applied to precise on-line
surface measurement, a synchronic phase-shifting technique is proposed. Its anti-vibration
characteristics are analyzed and a vibration table to simulate different vibration conditions is set up,
on which many experiments for surface measurement under different vibration conditions are
conducted. The analysis and experimental testing verify the excellent anti-vibration characteristics
of the interferometer for on-line precise surface measurement.
Optical Surface Finish of PCD Composites by Dynamic Friction Polishing
Authors: Chen Y. , Zhang Liang Chi , Arsecularatne Joseph A.
Published: March 2009

This paper presents a cost-effective technique for achieving optical surface finish of
thermally stable polycrystalline diamond (PCD) composites using dynamic friction polishing
(DFP). The effect of polishing parameters on the material removal rate and surface characteristics
of polished specimens were studied. The surface characterisation was carried out by optical
microscopy, atomic force microscopy (AFM), scanning electron microscope (SEM) and its attached
energy dispersive X-ray (EDX) analysis. It was found that optical surface finish of PCD with
roughness Ra = 50 nm could be obtained efficiently with nearly a ten fold reduction in polishing
time compared to the currently used method in industry.
Improving Machining Accuracy of the EMM Process through Multi-Physics Analysis
Authors: Lee Shuo Jen , Lai J.J. , Lee Yu Ming , Lee Chi Yuan , Yang K.T. , Peng C.W.
Published: March 2009

In this study, the parametric effects of the EMM process were studied by both numerical simulation and experimental tests. The numerical simulation was performed using commercial software, FEMLAB, to establish a multi-physics model which consists of electrical field, convection and diffusion phenomena to simulate the parametric effects of pulse rate, pulse duty, electrode gap and inflow velocity. From the simulated results, the relationship between parameters and the distribution of metal removal could be established. Proper process variables were also chosen to conduct the EMM experiments. After the experiments, the profile of the processed rectangular slot was measured by a Keyence digital microscope. Comparing profile of the processed rectangular slot with the profile of the cathode, the machining accuracy of EMM process could be determined. It could also verify the goodness of the multi-physics model for predicting machining accuracy. From this study, the effects of parameters such as pulse rate, pulse duty, electrode gap and inflow velocity are better understood. The simulation model could be employed as a predictive tool to provide optimal parameters for better machining accuracy and process stability of the EMM process.
A Contact Stylus Profilometer Based on Linnik Interference Microscope
Authors: Yun Jian Ping , Zhang Ling Ling , Xie Tie Bang , Hu Guo Yuan
Published: March 2009

We have constructed a novel contact stylus profilometer which is, in a certain sense, a combination of a lever system, an x-y stage, a vertical scanning stage and a Linnik microscope interferometer with a spatially and temporally incoherent light source. The system has large measurement range, high precision and small touch force. Its vertical measuring range is ±5 mm with a resolution below 2 nm, and the horizontal measuring range is ±25 mm in x- and y-range with a resolution of 1.25 μm. This paper describes the system and its performance along with results of measuring some samples.
The Integrated Packaging Process for Optical Sensor and RFID Used in Harsh Environment Conditions
Authors: Wu Chih Wei , Shen Yung Kang , Lee Chung Un , Wei Chung Sheng , Hsiao Chun Ching
Published: March 2009

Many technologies, such as Radio Frequency Identification (RFID), have been developed
to keep pace with rapid changes in society. Additionally, an RFID tag can be integrated with a
sensor or actuator (a smart RFID), they can comprise a sensitive wireless network. The potential
and utility of smart RFID techniques have increased dramatically. However, based on the
distinctive characteristics of RFID and sensors/actuators, they cannot be combined simultaneously
using commercial RFID techniques and materials such as poly phenylene sulfide (PPS).
Conversely, smart RFID systems will be exposed to harsh environments, including temperature
variations, salt corrosion, and violent impact. The current polymeric RFID packaging technique
cannot withstand severe environmental conditions for a long period. This study presents a novel
integrated packaging technique for sensors and RFID that is fully compatible with the
complementary metal-oxide-semiconductor (CMOS) processes to identify the limitations of
traditional RFID packaging methods. After several tests in harsh environments, such as strength,
corrosion resistance, thermal stress, and simulated washing, the RFID and sensor operated
normally. Therefore, the novel encapsulation process for RFID integrated with a sensor overcomes
the bottleneck of conventional RFID packaging techniques. The potential of this novel technique is
significant and provides a new approach as it achieves high performance and at a low cost.
Furthermore, the proposed new technique should prove very useful in applications as smart RFID
areas.
Review of Etchants for Copper and its Alloys in Wet Etching Processes
Authors: Çakır Orhan
Published: March 2009

Wet etching processes have been widely used for producing micro-components for various applications. These processes are simple and easy to implement. The selection of suitable chemical solution which is called etchant is the most important factor in the wet etching processes. It affects etch rate and surface finish quality. Copper and its alloys are important commercial materials in various industries, especially in electronics industry. Their wide applications are due to their excellent electrical and thermal conductivity, ease of fabrication, good strength and fatigue properties. The present study examines the possible etchants for copper and its alloys and reviews studies in detail to find out optimum etchant and its application parameters. The study is also aimed to provide information about safety, health and environmental issues caused by using various etchants in wet etching processes of copper and copper alloys.
ASPHERO5 – Simulation and Analysis of Aspherical Polishing Process
Authors: Boerret Rainer , Kelm Andreas , Thiess Helge , Giggel Volkmar
Published: March 2009

ASPHERO5 is a funded German research project (project prime: Schneider
OpticalMachines) with the goal of economic fabrication of high precision aspheres. The research is
concentrated on the classical process chain consisting of grinding and polishing. The
characterization of the incoming and outgoing surface quality is one issue to characterize the
improvements. The variation of the local removal rate related to local curvature is one of the
limiting factors of the polishing process. In this paper we report on first results characterizing the
surface quality with a PSD (Power Spectral Density) algorithm and analyzing the local removal
rates for the polishing step. In our research, two types of aspheres with 30 and 60 mm diameter
were polished with a spinning tool process. The final deviation between simulation and experiment
was less than 10 percent. That’s the starting point for further investigations within the project.
Feasibility Study on UV YAG Laser Patterning on Diamond Film
Authors: Tsai Hung Yin , Ting Chia Jen , Kuo Kei Lin , Chou Chang Pin
Published: March 2009

The laser ablation technique is one option for micro-machining and patterning of
diamond film. A UV YAG laser with higher energy density can remove or destroy the diamond film
more efficiently than the excimer laser. That is, the UV YAG laser not only provides faster etching
rate on the diamond film, but also requires less processing and maintenance cost. In the current
study, synthetic diamond films with grain size of 30 μm were deposited on silicon substrate by
microwave plasma enhanced chemical vapor deposition (MPCVD) in the CH4/H2 mixture
atmosphere. A pulsed UV YAG laser (λ = 355 nm, 10 kHz) was employed to machine and remove
the diamond film. The diamond film surface was analyzed by SEM and Raman spectroscopy after
the laser machining. The beam size of YAG laser was adjusted to between 0.1 mm and 1.5 mm by
the trepan mechanism to approach the following defined scanning width. In order to shape a 4-inch
diamond wafer into a microstructure, the scanning width of the UV YAG laser was defined to 0.1
mm, 0.75 mm and to 1.5 mm in several loops. The results show that the laser-polishing effect can
be applied to the pretreatment of mechanical polishing of diamond wafer in the condition of 0.75
mm scanning width in 3 loops. From Raman spectrum, it could prove the mechanism of carbon
burning reaction during the laser processing and the residual carbon existing in the laser-patterned
area. The surface of diamond film is strongly affected by the laser processing and a better result
from the parameter of 0.75 mm scanning width in 3 loops is shown in the current study.
Toward the Accurate Coverage of Aspheric Surfaces Using Two-Dimensional Scanning Paths for Minimizing Regular Errors
Authors: Cheng Hao Bo , Zhi Jing Feng , Wang Yong Tian , Bian Jing
Published: March 2009

This paper describes a two-dimensional tool-path planning model for minimizing the regularly distributed errors or mid-frequency errors during computer controlled optical surfacing (CCOS) by optimally connecting different tool-path segments. The model was established based on a neuro-fuzzy algorithm, a path neighborhood function which is defined as a victorious output element calculated in a self-organization way, then, the optimum material removal function with a modified weight was derived. The material removal function was studied theoretically and the results of simulation present a Gaussian distribution feature. Discrete removal points and optimized tool-path grid were simulated. Finally, an experiment involving a parabolic mirror was performed for residual error removal and the two-dimensional tool-path planning algorithm was found to be valid.
Manufacturing of Mold Insert with Micro Fluidic Channel Using Micro Cutting Process
Authors: Jung Woo Chul , Heo Young Moo , Yoon Gil Sang , Shin Kwang Ho , Cho Myeong Woo , Seo Tae Il
Published: March 2009

Recently the polymeric LOC (lab-on-a-chip) has been developed by the bio technology and the micro electro mechanical system technology. It is possible that biological experiment and analysis is executed rapidly and easily using a simple specimen. Therefore, many researches on LOC are progressing actively in various fields such as medical, biotechnical, environmental aspects etc. Up to the present time, most of polymeric LOC has been manufactured by LIGA (lithograpie galvanofomung abformung) or chemical etching processes. However, these methods have several disadvantages which are the complicated fabrication stages, requirements for various special equipments and limitations of materials. In this study, in order to overcome these difficulties, the possibilities of micro fluidic channel features were executed by micro cutting process for the steel. So the micro mold insert with micro fluidic channel was designed and manufactured by micro cutting process for the injection molding.
Metal Bipolar Plate with Micro Sensors
Authors: Lee Chi Yuan , Lee Shuo Jen , Dai Ching Liang , Hsieh Chi Lieh , Lee Yu Ming
Published: March 2009

The fuel cell has the potential to become an indispensable source of electric power.
However, some problems have not yet been resolved. Measuring the temperature and humidity
inside the fuel cells is currently difficult. Accordingly, in this study, micro sensors were fabricated
within the fuel cell, in which the temperature and humidity distributions were measured.
The substrate of the fuel cell was made of stainless steel (SS-304) and etching was employed to
fabricate the channel on the stainless steel substrate. Then micro-electro-mechanical-systems
(MEMS) technology was used to fabricate the array micro temperature and humidity sensors on the
rib of channel of stainless steel. The advantages of array micro temperature sensors are their small
volume, their high accuracy, their short response time, the simplicity of their fabrication, their mass
production and their ability to measure the temperature at a precise location more effectively than
the traditional thermocouple. The micro humidity sensors were made from gold and titanium as
down and up electrodes in the channel. The performance curve of the single cell was operating at
41.54 °C and gas flow rates of H2/O2 at 200/200ml/min. The max power density of the bipolar with
micro sensor was 56 mW/cm2.
Research of Vacuum Pump with Nano-Lubricant
Authors: Jwo Ching Song , Jeng Lung Yue , Chang Ho , Chen Sih Li
Published: March 2009

This study used the Al2O3 nano-lubricant produced from the direct synthesis method was
used as the experimental samples and the ultrasonic vibration was used for dispersing the
nanoparticles into three types of the weight fraction (0.1, 0.2, 0.3%wt). The base solvent was the
lubricant of vacuum pump. The objectives of this study were to discuss the dependence of operating
temperature of vacuum pump under the various weight fraction of Al2O3 nanoparticles. In this
experiment we added Al2O3 nano-lubricant into the direct drive oil sealed rotary vacuum pump, and
used the thermocouple measure the temperature on the four test points (cylinder, in-lubricant, case
of vacuum pump and discharge pipeline). The results show that the cylinder temperature was
reduced by 1.3% and increased by 0.4%, 1.8%, the lubricant temperature was increased by 5.3%,
0.5% and 1.9%, the case surface temperature was reduced by 1.7%, 1.4% and 1.5%, and discharge
pipeline temperature was reduced by 0.6%, 2.1% and 3.8% respectively when the sample fractions
were 0.1%, 0.2% and 0.3%wt. From the results, it could be realized that the nano-lubricant has
more effects on increasing the performance of heat sink than conventional lubricant.
Microscopic Examination of the Fracture Surfaces of an H 13 Hot Extrusion Die due to Failure at the Initial Usage Stage
Authors: Tseronis D. , Sideris I.F. , Medrea C. , Chicinaş Ionel
Published: March 2009

This paper studies the fracture surfaces of an aluminium hot extrusion die that broke down during operation. The die was constructed, from H13 steel and was intended for the production of 60,000 Kg of aluminium profile. The male part fractured during operation after the production of 500 Kg profile. Initially, the machine and thermal treatments that were applied for construction of the die were collected and studied. The die was carefully inspected visually with a stereoscope. The fracture surfaces, some cracks, and the structure that was not affected by the failure, were investigated by optical microscopy. The thickness, quality and homogeneity of the nitrated layers were inspected. Additional information concerning the fracture was obtained by examining a primary crack using a scanning electron microscope and chemical analysis of the material was made using EDX attachment. The paper reports on some interesting observations relating to the fractured component, the type of the fractures, and the quality of the heat treatments, and presents some of the probable causes that led to the premature failure of the die.
Improvement of Chemical Liquid Vaporized Infiltration Process for Fast Densification of Carbon/Carbon Composites
Authors: Zhang Yong Hui , Wang Ji Ping , Jin Zhi Hao
Published: March 2009

An improved chemical liquid vaporized infiltration process was developed to fast densify
carbon/carbon (C/C) composites. A disc-shaped carbon felt was chosen as preform, whose upper and
lower sides were fixed and heated simultaneously by two flat surfaces of two heat sources, and the
precursor was heated by the third heat source separated. By this method, carbon felts (bulk density
~0.2 g/cm3) were densified to C/C composites with density of 1.29, 1.61 and 1.72 g/cm3 when prepared
for 3h at 900°C, 1000°C and 1100°C, respectively. Scanning electron microscopy (SEM) reveals that the
carbon fibers of the composite are surrounded by ring-shaped pyrocarbon. The deposition process is
analyzed by dividing the reactor into four regions associated with specific functions and the reasons for
the rapid fabrication are proposed as the short convection and diffusion path for the precursor and the
existing thermal gradients across the preform.
High Temperature Tribology and Solid Lubrication of Advanced Ceramics
Authors: Ouyang Jia Hu , Murakami Takashi , Sasaki Shinya , Li Yu Feng , Wang Ya Ming , Umeda K. , Zhou Yu
Published: March 2009

The high-temperature friction and wear characteristics of different ceramics and ceramic
matrix composites (CMCs) incorporated with various solid lubricants have been investigated from room
temper- ature to 1000oC. The solid lubricants considered in this paper include representative precious
metals, hexagonal boron nitride, graphite, fluorides, soft oxides, chromates, sulfates, and combinations of
various solid lubricants. General design considerations relevant to solid lubrication were proposed on the
basis of friction and wear data of self-lubricating CMCs. The self-lubricating composites incorporated
with SrSO4 or/and CaSiO3 exhibits low and stable friction coefficients of 0.2 to 0.3 and small wear rates in
the order of 10-6 mm3/Nm from room temperature to 800oC. The optimized composites appear to be
promising can- didates for long-duration, extreme environment applications with low friction and small
wear rate.
Preparation and Phase Analysis of Fe-SiAlON-MoSi2 Composites
Authors: Yang Jing Zhou , Huang Zhao Hui , Fang Ming Hao , Liu Yan Gai , Wu Xiao Xian
Published: March 2009

Fe-SiAlON-MoSi2 composites were prepared using FeSi75, α-Al2O3, and MoSi2 powders as
starting materials at 1400 oC, 1500 oC, 1600 oC and 1700 oC, respectively, for 3h in a flowing nitrogen
under the pressure of 0.9MPa. The results showed that the main phases of Fe-SiAlON-MoSi2 composite
were β-SiAlON with deferent Z-values, MoSi2, and Fe3Si. Z-value of the obtained β-SiAlON depanded on
α-Al2O3 content and the sintering temperature. The morphology of SiAlON phase changed from fibre-like
of low Z-value to hexagonal prism-like of high Z-value.
Intermetallic Alloys Ni3Si and Ni3(Si,Ti): Microstructures and Properties
Authors: Fan Ding , Sun Yao Ning , Zheng Min , Zhang Jian Bin , Zheng Yu Feng
Published: March 2009

Laser cladding experiment was carried out with a 5 kW continuous wave CO2 laser by preplacing Ni75Si25 and Ni78Si13Ti9 powders onto Ni-based superalloy substrate. The microstructure of the specimens was monitored by using optical and scanning electron microscopy. The chemical compositions of the alloys and their phases were obtained using X-ray diffraction and energy dispersive x-ray spectroscopy. The phase transformation temperatures were determined by non-isothermal differential scanning calorimetry tests. The microhardness of the laser cladded sample was measured.
Fabrication and Biocompatibility of Gradient Bioceramic Coatings on Titanium Alloy Substrate by Laser Cladding
Authors: Zheng Min , Fan Ding , Li Xiu Kun , Liu Qi Bin , Li Wen Fei , Zhang Jian Bin
Published: March 2009

Based on a high power CO2 laser beam passing by pyramid polygon mirror, the bioceramic coatings of gradient composition were fabricated on titanium alloy substrate (Ti-6Al-4V). The relations among laser processing parameters, microstructure and biocompatibility of the gradient bioceramic coatings were investigated. The results indicated that the contents of rare earth oxide additions had an immediate effect on the formation of bioactive phases. The gradient bioceramic coatings showed favorable biocompatibility in vivo after they were implanted into canine femur for 45, 90, and 180 days, respectively. The bioceramic coatings of Ca/P=1.4 and 0.6wt.% Y2O3 totally combined with new bones merely implanted for 45 days. Furthermore, the MTT (Methyl Thiazolyl Tetrazolium) colorimetry results of cell proliferation demonstrated that the cell growth distinctly increased on the gradient bioceramic coatings by laser cladding compared with the un-treated titanium alloy substrate.
Preparation of Porous Polycaprolactone Scaffolds by Using Freeze-Drying Combined Porogen-Leaching Methods
Authors: Ning Cheng Yun , Cheng Hai Mei , Yin Zhao Yi , Zhu Wen Jun , Chen Hao , Lei Shu Mei , Yin Shi Heng , Liu Hua Guo
Published: March 2009

The microstructure of scaffold was one of key factors for tissue engineering. Porous
polycaprolactone (PCL) scaffolds were fabricated by combination of porogen-leaching and freeze-drying
process. Ice particulates were used as porogen material, and PCL solutions in chloroform were mixed
with ice particulates for 5minuture at zero temperature. Then the mixture was freezed in liquid nitrogen,
and porous scaffold was prepared by freeze - drying finally. The microstructure and properties of the
scaffolds were investigated. Porous structure of the scaffolds showed that good 3D microstructure and no
porogen remained in the scaffold; pore size and porosity were determined by the size and mass fraction of
ice particulates. The results demonstrated that the Scaffolds possessed open and interconnected pores
with sizes ranging from several μm to more than 300μm and porosities of 50~80%.
Effect of Multiple Firing on Wear Behavior of Dental Veneering Ceramic
Authors: Gao Q.P. , Chao Yong Lie , Guo F. , Jian Xin Chun , Xu C.J.
Published: March 2009

This study investigated the effect of multiple firing on the wear behavior of dental all-ceramic
veneering ceramic (Cercon). Samples were fabricated according to the manufacturer's requirement for
different firing times. The wear test was operated under simulated oral environment. The results showed
that multiple firing could influence wear behavior of all-ceramic Veneer. Significant difference was
observed in wear scar width among different samples. All the groups except 7time-firing one showed
good wear resistance with low wear rate, smooth surface and relatively constant frictional coefficient.
With the increasing firing times the wear scar width became larger. The wear resistance of dental ceramic
after seven times firing was significantly lower. SEM/DFM results showed the wear facets of veneering
ceramic demonstrate grooves characteristic of abrasive wear. The significant change was that severe wear
dominated by brittle fracture could be seen in the 7time-firing group. Multiple firing can decrease the
wear resistance of dental all-ceramic Veneer, and the wear pattern has the tendency to severe wear. The
possible explanation is that the microstructure and properties of all-ceramic Veneering changed during
multiple firing.
Effect of Cr Additives on the Microstructures and Properties of Laser Cladded Ni3Si
Authors: Zheng Yu Feng , Zhang Jian Bin , Sun Yao Ning , Fan Ding , Zheng Min
Published: March 2009

Three compositions, (Ni75Si25)-5Cr, (Ni75Si25)-10Cr and (Ni75Si25)-15Cr, have been
cladded onto Ni-based suaperalloy substrate by pre-placing laser cladding process with a 5 kW
continuous wave CO2 laser. Ni75Si25 was also cladded with the same method for comparison. The
process parameters have been optimized to obtain defect free claddings. The microstructure and the
hardness of the cladded layers were characterized by optical microscopy, scanning electron microscopy,
X-ray diffraction and microhardness measurement. The corrosion resistance of the cladded layers was
measured in a sulfuric acid solution.
Triboluminescence of SrAl2O4:Eu Film with Strong Adhesion Fabricated by a Combination of RF Magnetron Sputtering and Post-Annealing Treatment
Authors: Yamada Hiroshi , Fu Xiao Yan , Xu Chao Nan
Published: March 2009

Strongly adherent SrAl2O4:Eu films were fabricated on the rough surface of an alumina
substrate by a combination of the RF magnetron sputtering technique and a post-annealing treatment. A
crystalline SrAl2O4:Eu2+ film was achieved after annealing at 1000°C in reduced atmosphere and it
exhibit a intensively green PL and triboluminescence (TL) while an as-deposition film showed the
amorphous state and weakly red photoluminescence (PL). It was found that the fabricated films possessed
a strong durability of a friction, exhibiting no peeling, cracking, and breaking in the films after TL
measurements. These results will facilitate a development of novel TL skin sensors.
Photocatalyses of Nano-Scaled ZnSe/TiO2 and ZnS/TiO2 Heterojunctions
Authors: Lee Ming Kwei , Shih Tsung Hsiang , Ho Chen Lia , Lee Hung Chang , Yen Chih Feng , Tu Hwai Fu , Fan Cho Han
Published: March 2009

High quality nano-scaled fluorine and nitrogen co-doped anatase phase TiO2 can be obtained
from the conversion of ammonium oxotrifluorotitanate by thermal treatment. The photocatalytic activity
of TiO2 treated at 800oC shows the highest photocatalytic activity and is about 1.3 times of commercial
P-25. The heterojunctions of ZnSe/TiO2 and ZnS/TiO2 prepared by metal organic vapor phase epitaxy
shows 2.0 and 1.5 times the photocatalytic activities of commercial P-25. In this study, nano-scaled TiO2,
ZnSe/TiO2 and ZnS/TiO2 heterojunctions show one to one correspondence between carrier lifetime and
photocatalytic activity.
Preparation and Characterization of Macroporous Pumice-Porcelain Composite Foams
Authors: Wu Zhen Jiang , Chen Yun Fa , Yu Yeon Tae
Published: March 2009

The open-cell macroporous ceramic foams can be used to air and water decontamination after
loading catalyst. A new kind of ceramic foam was prepared using pumice, porcelain stone, quartz as main
raw materials and polyurethane sponge as template. During the process, the polyurethane sponges were
immersed in the powder slurry while submerged to fill all the pores, which makes it uniformly coating the
sponge. Then the samples were dried at 80°C, and then sintered at 1050°C -1200°C for 2h in air. The
ceramic foams present high porosity from 75% to 90%, higher compassion strength from 10 MPa to
50MPa and lower volume density from 0.15g/cm3 to 0.32g/cm3. The SEM images revealed the open-cell
structure in the product.
Sintering and Microwave Dielectric Characteristics of ZnTa2-xxNbxO6 Ceramics
Authors: Cheng Chien Min , Chen Ying Chung , Yang Cheng Fu
Published: March 2009

The effects of Nb2O5 content upon the microwave characteristics of ZnTa2−xNbxO6 ceramics
are investigated. The appropriate sintering temperatures of ZnTa2−xNbxO6 ceramics slightly decrease with
the increase of Nb2O5 content, and the densities and dielectric constants of ZnTa2−xNbxO6 ceramics
linearly decrease with the increase of Nb2O5 content. As the Nb2O5 content increases, the Q×f value of
ZnTa2−xNbxO6 ceramic first decreases, reaches a minimum value at x=1.0, then increases and reaches a
maximum value at x=2.0. The τf values of ZnTa2−xNbxO6 ceramics are positive for x≤0.3, and change to
negative ones as x≥0.6.
Prediction of the Properties of an Alumina Green Body Using an Artificial Neural Network by a New PSO-Gain Backpropagation Algorithm
Authors: Li Bing , Zhong Hui Ling , Li Hong Jie , Chen Ling , Li Lin , Li Xiao Xi
Published: March 2009

Artificial neural networks have been successfully used in classification, formulation optimization,
defect diagnosis and performance prediction in ceramic industry. However, an artificial neural
network based on the traditional backpropagation (BP) algorithm showed some disadvantages in mapping
the nonlinear relationship between the composition and contents of the ceramic materials and their
properties. In this paper, a new PSO-Grain (Particle Swarm Optimization Gain) BP algorithm was
introduced, and an improved artificial neural network model was employed to predict the properties of an
alumina green body. The training performance of the neural network using the PSO-Gain BP algorithm
was analyzed and it was indicated the POS-Gain BP based neural network could reduce convergence to
local minima and was more efficient than the traditional BP based network. The prediction accuracy of
the properties such as linear shrinkage and bending strength using the PSO-Gain BP based neural network
was higher than that of the BP based neural network.
Damage Finite Element Analysis of Nano- Composite Ceramics
Authors: Kang Jing Xin , Ni Xin Hua , Zheng Jian , Zhao Yong Ling
Published: March 2009

Based on experiments, micro-mechanics and finite element theory, nanocomposite ceramics is
simplified as representative volume cell in the paper, and in order to study the interaction of the particles,
each cell concludes two nano-ceramic particles. We use ANSYS program to construct the cell model and
simulate the stress field. The stress distribution and the material properties are obtained. The results show
that the stress is uneven in the cell and the elements near the nano-ceramic particle with high stiffness will
damage first. Finely, the stress change and damage evolution route are simulated by using the element
birth and death technology. The computational results are accordance with experiments and theories.
Negative Thermal Expansion of Yb2Mo3O12 and Lu2Mo3O12
Authors: Xiao X.L. , Wu M.M. , Peng J. , Cheng Y.Z. , Hu Zhong Bo
Published: March 2009

Compounds Yb2Mo3O12 and Lu2Mo3O12 were prepared by conventional solid-state reaction.
Their crystal structures and thermal expansion properties were investigated. It was found that Yb2Mo3O12
and Lu2Mo3O12 adopt orthorhombic structure and show negative thermal expansion (NTE) in the
temperature range of 200-800 °C. Their a-axis and c-axis exhibit stronger contraction in the temperature
range of 200-800 °C, while b-axis slightly expands in the temperature range of 200-300 °C and then
contracts in the temperature range of 300-800 °C. The linear thermal expansion coefficients al of
Yb2Mo3O12 and Lu2Mo3O12 are −5.17 × 10−6 °C−1 and −5.67 × 10−6 °C−1, respectively.
Preparation and Dielectric Properties of BaO-Sm2O3-4TiO2 Microwave Ceramics with B2O3 and CuO Addition Sintered in Low Temperature
Authors: Liu Wei Liang , Tang Chun Bao , Tan Jun , Mao Du Song , Tan Jin Gang
Published: March 2009

BaCu(B2O5) (BCB) powder was prepared using BaO,CuO and B2O3 as the main materials.
Microwave dielectric ceramics of tungsten–bronze-type BaSm2Ti4O12 (BST) were prepared by doping
BCB as the sintering aid. The amount of BCB was varied from 1.0 to 10.0wt.%. The microstructure and
dielectric properties of BST were investigated. The sintering temperature of BST ceramics with 6.0wt.%
BCB addition can be effectively reduced to 900 oC, about 450 oC lower than that of pure BST ceramics.
Good microwave dielectric properties of εr = 62.38, Q×f = 4573 GHz and τf = -27.65 ppm/ oC were
achieved.
Piezoelectric and Dielectric Properties of Bi2O3-Doped (Bi0.5Na0.5)0.94Ba0.06TiO3 Lead-Free Piezoelectric Ceramics
Authors: Hu Jian Qiang , Chen Zhi Wu
Published: March 2009

Bi2O3 doped (Bi0.5Na0.5)0.94Ba0.06TiO3 (BNBT6) lead-free piezoelectric ceramics were
fabricated by a conventional sintering technique. The effects of Bi2O3 on the piezoelectric properties and
microstructures of the doped BNBT6 were investigated. X-ray diffraction analysis showed that a solid
solution was formed when Bi2O3 diffused into BNBT6 lattice and the crystal structure of the sintered
hybrid changed from rhombohedral to tetragonal symmetry with increasing Bi2O3 amount. Piezoelectric
and dielectric properties measurements revealed that doping Bi2O3 within a certain range enhanced the
piezoelectric coefficient (d33), electromechanical coupling factor (kp), relative dielectric constant
(ε33
T/ε0), and dielectric loss (tanδ). When 3mol% Bi2O3 was doped, both d33 and kp of the ceramics
reached their maxima, 165pC/N and 24%, respectively.
Finite Element Analysis and Design of Monolithic Multilayer Piezoelectric Micromanipulator
Authors: Chu Xiang Cheng , Huang Jin Ding , Li Long Tu , Gui Zhi Lun
Published: March 2009

A novel model of 3-DOF multilayer PZT micromanipulator is promoted and simulated with
finite element analysis method. States under different applied voltages were discussed, including the
motion along axis Z and the rotation along axis X and the bisector between X-Y. After analyzing the
distribution of stress, we propose some method, which helps to improve the performance of the
micromanipulator. We also do some quantificational analysis about the micromanipulator, discovering
that the relationship between the displacements of the probe and applied voltages is almost perfectly
linear. By comparing the constant D defining the relationship of the displacements of probe tip and
applied voltages, the simulation is proved to be correct. Comparing the performance between the
single-layer and multi-layer PZT, it shows that the multi-layer PZT can reduce input voltages, whereas
can produce the same displacement. Ceramic sample is prepared for further experiment.
A Novel Piezoelectric Nebulizer
Authors: Yuan Song Mei , Yan Lu Tao , Liu Qiang
Published: March 2009

A novel nebulizer used in near dry machining systems for supplying cutting fluids and cooling
air is presented. The nebulizer includes double-layer micro-nebulizers, each adopting piezoelectric
transducer as the actuator, generating pressure in the chamber and ejecting liquid or air out of it. The
mixture of cooling air and micro-partical spraying into cutting area has both the cooling and lubricating
action. The design of the piezoelectric actuator and cavity structure, including the selection of the piezoelectric
actuator type and materials is studied. The vibration modes are obtained by means of FEM.
Fabrication of Piezoelectric Cantilever Beam Based on Nanostructured PZT Film
Authors: Liu Hong Mei , Zhao Quan Liang , Qiu Cheng Jun , Cao Mao Sheng
Published: March 2009

A sol-gel technology to fabricate PZT thick film for cantilever beam was investigated. In this
process, PZT nano-powder is dispersed into a PZT sol solution, which is identical with the powder in
composition, and then the PZT suspension and clean PZT sol solution were deposited alternately on an
Au/Cr/SiO2/Si substrate using spin-coating route. Above process was repeated in order to deposit the
desired thickness. The results showed that the perovskite PZT thick film with thickness of about 4 μm was
obtained after annealing at 650 °C for 2 h and it has the saturation polarization of 54 μC/cm2, the remnant
polarization of 30 μC/cm2 and the coercive field of 50 kV/cm.
Electrical Characteristics of Fluorine Passivated MOCVD-TiO2 Film on (NH4)2Sx Treated GaAs
Authors: Lee Ming Kwei , Yen Chih Feng , Shih Tsung Hsiang , Ho Chen Lia , Lee Hung Chang , Tu Hwai Fu , Fan Cho Han
Published: March 2009

The high Dit is the major problem of III-V compound semiconductor MOSFET, which causes
the pinning of the surface Fermi level near the middle of the energy gap. The GaAs with (NH4)2Sx
treatment (S-GaAs) can remove the native oxides on GaAs and prevent it from oxidizing. The electrical
characteristics of fluorinated polycrystalline TiO2 films deposited on p-type(100) S-GaAs were
investigated. The fluorine from liquid phase deposition solution can passivate the grain boundary of
polycrystalline TiO2 prepared by MOCVD. The leakage current through the grain boundaries was
suppressed. The leakage current of MOCVD-TiO2/S-GaAs can be improved from 6.8 x 10-6 and
0.2 A/cm2 to 3.41 x 10-7 and 1.13 x 10-6A/cm2 under positive and negative electric fields at 1.5 MV/cm,
respectively. Dit and k can be improved from 1.44 x 1012 cm-2eV-1 to 4.6 x 1011 cm-2eV-1 and 52 to 65,
respectively. The effective oxide charges can be improved from 2.5 x 1012 C/cm-2 to 9.3 x 1011 C/cm-2.
Effect of Moisture on Chemical Stability and Hydrogen Permeability of Ni-BaCe0.9Y0.1O3-δ Cermet
Authors: Fang Shu Min , Yang Jing , Chen Chu Shen , Liu Wei
Published: March 2009

Ni-BaCe0.9Y0.1O3-δ mixed protonic-electronic conductor can be used to separate hydrogen from syngas. Considering that water exists in syngas, it is necessary to evaluate the effect of moisture on chemical stability and hydrogen permeability of the cermet. In this paper, hydrogen permeation rates of Ni- BaCe0.9Y0.1O3-δ (40:60 in volume ratio) in different water partial pressures were measured at intermediate temperatures (600-750°C). It is found that hydrogen permeation rate of the cermet is highest at an appropriate water partial pressure. Samples after experiment were analyzed by XRD, ICP and pH value measurement, in which Ba(OH)2 and doped CeO2 were found. The reaction of water with samples resulting in insulating Ba(OH)2 and doped CeO2 is contributed to the decrease of hydrogen permeation in excessive water partial pressure.
Preparation and Spectral Properties of PVP-Modified ZnO Nanorods
Authors: Huang Yang Feng , Xiao Han Ning , Chen Shu Guang
Published: March 2009

ZnO nanorods were prepared by a hydrothermal reaction in the presence or absence of PVP
(polyvinyl pyrrolidone). The obtained products were characterized by means of X-ray diffraction,
scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, UV-Vis
absorption (UV) spectroscopy and photoluminescence (PL) spectroscopy. The results suggest that PVP
plays an important role in the preparation of ZnO nanorods. The UV absorption spectrum showed PVP
increases the UV-shielding ability but doesn’t influence the transparency in the visible light region. A
weak UV emission at 353 nm of PL spectra exhibit the surface of ZnO nanorods is passivated and
oxygen-related defects is supplied by PVP.
Magnetic and Dielectric Properties of BST-YIG Composites
Authors: Li Jun Chu , Li Xiang , Yang Gang , Yue Zhen Xing
Published: March 2009

xBST-(1-x)YIG composite ceramics with x=0~1 were prepared by solid-state reaction method. The variations for phase compositions were determined by XRD, and the magnetic and dielectric properties of the composites were studied in the frequency range of 100Hz~1GHz. The results showed that the composites (x=0.1~0.9) are consisted of BST phase and YIG phase and no significant chemical interaction occurs between these two phases. The composite materials exhibit excellent frequency dependences of dielectric and magnetic properties. The resonance frequency and high frequency characteristics of YIG are improved by additions of BST, and when x=0.3, xBST-(1-x)YIG has the best dielectric and magnetic properties.
Nano-Crystalline Barium Hexaferrite Powders Prepared by Mechanical Alloying Using Acetate Precursor
Authors: Honarvar Nazari M. , Ataie Abolghasem , Seyyed Ebrahimi S.A.
Published: March 2009

Nano-crystalline barium hexaferrite powders have been prepared by mechanical alloying of
nFe2O3+Ba(CH3COO)2 with Fe/Ba molar ratios of 10-12 and subsequent heat treatment. Thermal
behavior, phase composition, morphology and magnetic properties of samples were studied using
DTA/TGA, XRD, SEM and VSM, respectively. Nano-crystalline Ba-hexaferrite with a mean crystallite
size of 46 nm and magnetic properties as high as Ms = 73.9 A.m2/kg and Hci = 334.2 kA/m was formed for
mixture of 5.5Fe2O3+Ba(CH3COO)2 which was milled for 48 h and then annealed at 1100 °C.