bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Oxygen Vacancies on the Polarization Properties in Bi4Ti3O12 Ferroelectric Single Crystals
Authors: Noguchi Yuji , Matsumoto Takahiro , Miyayama Masaru
Published: March 2009

Measurements of the leakage-current and polarization properties in bismuth titanate (Bi4Ti3O12)
along the a axis show that the crystals grown in air followed by air annealing at 700oC had a
superior remanent polarization of 48 μC/cm2 as well as a low leakage current density of the order of
10-9 A/cm2. The annealing at a high oxygen partial pressure of 35MPa (700oC) resulted in a higher
leakage current, indicating that electron holes arising from the incorporation of oxygen at oxygen
vacancies act as detrimental carriers for electrical conduction at room temperature. A crystal growth
under high-pressure oxygen atmosphere and subsequent annealing at a moderate oxygen partial
pressure is proposed to be advantageous for suppressing the vacancy formation and for attaining a
large remanent polarization as well as a high insulating property of the Bi4Ti3O12 system.
Proton Conducting Properties of Layered Metal Phosphate Hydrates
Authors: Kawakami Yosuke , Miyayama Masaru
Published: March 2009

The proton conducting properties of layered metal phosphates hydrates (M (HPO4)2·nH2O (M = Sn,
Ti, Zr), MPs) were examined under various humidities at 20−150°C. SnP showed a high
conductivity of more than 10-2 S cm-1 under saturated water vapor pressure and a weak humidity
dependence of its conductivity at 150°C. The hydrated water content (n) of ZrP was approximately
stable at 1 in a wide humidity range of more than 20% at 150°C. The n of SnP varied more widely
than that of ZrP; however, the conductivity of SnP remained high even in a low-n range. The short
distance between adjacent hydrated water molecules was suggested to be the reason for the high
proton conductivity of SnP.
Crystal Growth and Electric-Field-Induced Strain in Bi0.5Na0.5TiO3 Crystals
Authors: Yoshimura Sho , Noguchi Yuji , Miyayama Masaru
Published: March 2009

Large Bi0.5Na0.5TiO3 (BNT) single crystals with 10 mm × 10 mm × 5 mm were successfully grown
by a flux method using BNT powder and the mixed flux composed of Bi2O3 and NaF. Dielectric
measurements show a dielectric-permittivity peak at 310°C, which is the result of the gradual phase
transition from rhombohedral (R3c) to tetragonal (P4bm) structure. Electric-field induced strain
measurements along [100]C reveal that the effective piezoelectric strain constant (d33
*) was
estimated to be 130 pm/V in a multidomain state.
B- and P-Doped Si0.8Ge0.2 Thin Film Deposited by Helicon Sputtering for the Micro-Thermoelectric Gas Sensor
Authors: Tajima Kazuki , Shin Woosuck , Nishibori Maiko , Murayama Norimitsu , Itoh Toshio , Izu Noriya , Matsubara Ichiro
Published: March 2009

Micro-thermoelectric hydrogen sensor (micro-THS) with the combination of the thermoelectric effect of Si0.8Ge0.2 thin film and the Pt-catalyzed exothermic reaction of hydrogen oxidation was prepared by microfabrication process. In the viewpoint of high sensitivity of micro-THS, the thermoelectric properties of the Si0.8Ge0.2 thin film could be improved by optimizing carrier concentration using helicon sputtering with an advantage of easy doping control, and sensitivity of the device with this thin film was investigated. As the result, the boron-doped Si0.8Ge0.2 thin film is considered to be the better choice ensuring the reliable monitoring of hydrogen concentration down to ppm level.
An Automated Measurement System of Ultrasonic Properties of Tofu and Acorn Curd (Dotori Muk)
Authors: Li Ying , Guntur S.R.Anjaneya Reddy , Choi Min Joo , Paeng Dong Guk
Published: March 2009

Tofu was suggested as Tissue Mimicking Materials (TMMs) due to its low cost,
availability, gelatinous nature, and shape flexibility. However, the similarity in acoustic properties of
the different packets of Tofu and acorn curd (Muk) is critical for TMMs but not fully investigated yet.
In order to improve the accuracy for time-consuming and multi-stepped measurements of acoustic
properties, an automated measurement system was developed. Using the automated system, the
acoustic properties Tofu and Muk were measured to know whether they are similar among the
different samples. In conclusion, the acoustic properties were measured to be similar among the
different packets of Tofu and Muk, suggesting them as potential TMMs.
Detection of Listeria Monocytogenes Using an Automated Fiber-Optic Biosensor: RAPTOR
Authors: Kim Gi Young , Morgan Mark T. , Ess Daniel , Hahm Byoung Kwon , Kothapalli Aparna , Valadez Angela , Bhunia Arun
Published: March 2009

Fiber-optic biosensor uses light transmittable tapered fiber to send excitation laser light and receive emitted fluorescent light. The fluorescent light excited by an evanescent wave generated by the laser is quantitatively related to biomolecules immobilized on the fiber surface [1]. An automated fiber-optic biosensor based detection method for Listeria monocytogenes was developed in this research. Detections of Listeria monocytogenes in hotdog sample were performed to evaluate the method. By using the detection method with automated fiber-optic biosensor, 5.4×107 cfu/ml of Listeria monocytogenes was able to detect.
Numerical Analysis of Magneto-Optical Eddy Current Imaging Using FEM
Authors: Lee Jin Yi , Hwang Ji Seong , Shoji Tetsuo
Published: March 2009

Magnetic-optical film (hereafter, MO film) is a bismuth-doped iron garnet film grown on a
gadolinium gallium garnet substrate by liquid phase epitaxial method. Because an MO film has
physical characteristics such as Faraday rotation and magnetic anisotropy, the distribution of its
external magnetic field can be visualized. The MOI (Magneto-Optic/Eddy Current Imager) was
developed to detect far-side cracks and corrosions in aluminum alloy materials on an aircraft. The
detection probability of 2.5mm-length cracks is 90/95% when the MO film and the induced area
current are used. However, the quantitative evaluation algorithm for quantifying crack shapes and
sizes has yet to be proposed. This paper investigates a quantitative evaluation algorithm for magnetic
optical eddy current imaging by using the finite element analysis methods (FEM) and experimental
results. The MOI including a primary induction coil was simulated by FEM software. The position,
depth, shape, and the induction current frequency, lift-off were simulated and examined. A simplified
quantitative evaluation algorithm for MOI is proposed by using the analysis results.
Reliability of Buried Pipeline Using FORM and Monte Carlo Simulation
Authors: Lee Ouk Sub , Kim Dong Hyeok
Published: March 2009

The reliability estimation of pipelines is performed with help of the probabilistic method
which considers the uncertainties included in the load and resistance parameters. The FORM (first
order reliability method) is carried out to calculate the failure probability of corroded pipeline for the
classified six distribution types of random variables. And the reliability of pipelines is assessed by
using the failure probability. Furthermore, the MCS (Monte Carlo Simulation) is used to verify the
results of the FORM. It is noted that the failure probabilities of the linear and the power models for
surface corrosion are similar and those of the two-phase model for surface corrosion are somewhat
different for six cases of two failure pressure models such as ASME B31G and MB31G models. And
it is also found that the FORM and the MCS give similar results for varying exposure time.
Dynamic Stress Analysis Method and Its Application for Urethane Wheels Using the Computer Model
Authors: Jun Kab Jin , Yoon Ji Won , Park Tae Won , Park Joong Kyung
Published: March 2009

An Over Head Transportation (OHT) vehicle is used to transport large loads in a factory
more efficiently. To maximize productivity, the speed and load requirement for the OHT vehicle is
continually increasing. This may create a repetitive dynamic load and thus cause fatigue failure in
related components. In this paper, a computer aided engineering (CAE) method is proposed for
fatigue life prediction in the early design stage using multibody dynamic analysis and the linear
damage rule. The process of predicting the fatigue life using the proposed computer models in this
paper may be applied to structures of various mechanical systems.
Nondestructive Dynamic Process Monitoring Using Electrical Capacitance Tomography
Authors: Ijaz U.Z. , Kim J.H. , Kim M.C. , Kim Sin , Park J.W. , Kim K.Y.
Published: March 2009

In this paper, we propose a dynamic Electrical Capacitance Tomography (ECT) image
reconstruction algorithm based on the extended Kalman filter (EKF) to estimate the rapidly
time-varying changes in the permittivity within the time taken to acquire a full set of independent
measurement data. The ECT inverse problem is formulated as a state estimation problem in which the
system is modeled with the state equation and the observation equation. Computer simulation with
synthetic data is provided and comparison is done with existing modified Newton Raphson (mNR)
method to illustrate the reconstruction performance of the proposed algorithm.
Thermal Diffusivity and Phase Transition of Rare Earth Manganites
Authors: Kobayashi Migaku , Sato Hirohisa , Hiyoshi Yoshihiko , Kamegashira Naoki , Lee Doh Jae , Kim Hee Joon
Published: March 2009

Thermal diffusivity of nonstoichiometric PrMnO3 and NdMnO3 phases were measured by laser flash method from room temperature to 1100 K, in addition to the data of electrical conductivity, thermal analysis and high temperature X-ray diffractometry to detect the phase transition. The thermal diffusivity curve varied with increasing temperature and showed a clear anomaly with a sudden dip at the phase transition temperature. The transition temperature decreases with oxygen nonstoichiometry in each phase.
Experimental and Analytical Studies for Impedance-Based Smart Health Monitoring of Concrete Structures
Authors: Park Seung Hee , Ahmad Sohaib , Yun Chung Bang , Roh Yong Rae
Published: March 2009

This paper presents a feasibility study of an impedance-based damage detection
technique using PZT (Lead-Zirconate-Titanate) patches for real-time health monitoring of concrete
structures. The PZT patches are used to detect progressive surface damage on a plain concrete beam.
Both experimental and analytical studies are carried out. For damage quantification, root-mean
square deviations (RMSD) before and after damage are used as a damage indicator.
Numerical Simulation of Al-SPCC Weldment
Authors: Joo Sung Min , Bang Hee Seon , Bang Han Sur
Published: March 2009

Analytic procedure for dissimilar materials welding problem by using developed in-house
solver is applied on butt and lap jointed model. In addition, the procedure of data transferring between
commercial package and in-house solver for the preparation of input data for in-house solver has been
developed. Therefore we can use the commercial package as pre and post processor for in-house
solver and the results from in-house solver, for example, welding residual stress can be exported to
commercial package as initial value to the model and then further analysis with the application
of external loading can be carried out. For the similar material welding the welding residual stress has
been decided by temperature dependent material properties that are input to the source program. In the
case of dissimilar welding problem due to the difference of expansion and shrinkage rate between
aluminum and steel there has been a slight variation in this dependency. Since the aluminum has large
thermal expansion coefficient and the mechanical melting point is lower than steel, the order and level
of mechanical behavior like stress history become different.
The degree of mechanical deterioration of dissimilar materials welded model has been assessed with
various view aspects, namely, welding residual stress, plastic strain, equivalent plastic strain and
plastic work distribution and it has been revealed that Al5052 is mechanically more sever than SPCC
for same heat input.
Implementation of Performance Demonstration Programs for Steam Generator Tubing Analysts
Authors: Cho Chan Hee , Nam Min Woo , Jee Dong Hyun , Jung Jee Hong , Lee Hee Jong
Published: March 2009

The Korea Electric Power Research Institute (KEPRI) has developed performance
demonstration programs for non-destructive testing personnel who analyze ECT (eddy current
testing) data for steam generator tubing since 2001. The purpose of these performance demonstration
programs is to ensure a uniform knowledge and skill level of data analysts and contribute to safe
operation of nuclear power plants. Many changes have occurred in non-destructive testing of steam
generator tubing such as inspection scope, plugging criteria and qualification requirements in Korea.
According to the Notice 2004-13 revised by the Ministry of Science and Technology (MOST), the
analyst for steam generator tubing shall be qualified as the qualified data analyst (QDA), and the site
specific performance demonstration (SSPD) program shall be implemented. KEPRI developed these
performance demonstration programs and they are being successfully implemented. The analyst's
performance is expected to be improved by the implementation of these programs.
Wireless Instrumentation for Monitoring of Smart Structures
Authors: Kim Chi Yeop , Kwon Il Bum , Seo Dae Cheol
Published: March 2009

Smart structures needs lots of sensor installation to sense their status and also the external
environmental change. Wireless technique can give a good solution to install sensors without heavy
cables. So, in this work, a wireless device was developed to transmit static strain and elastic wave
propagation of structures. The specification of this device was as follows: 2.4 GHz of transmitted
frequency, 8 channels, 57,600 bps of the transmitted speed, and 10 mW of the transmitted power.
In order to confirm the wireless device’s feasibility, a beam test was performed with five optical
fiber strain sensors and two piezo-ceramic sensors with the wireless instrumentation.
Contribution of Three-Dimensional Trabecular Bone Microstructure of the Proximal Femur to its Mechanical Properties as Assessed by Micro-Finite Element Analysis
Authors: Cui Wen Quan , Won Ye Yeon , Baek Myong Hyun , Kim Kwang Kyun
Published: March 2009

The purpose of this study was to investigate the contribution of the microstructural properties of trabecular bone in predicting its elastic modulus in the intertrochanteric region. A total of 15 trabecular bone core specimens were obtained from the proximal femurs of patients undergoing total hip arthroplasty. The micro-computed tomography (micro-CT) was used to scan each specimen to obtain micro-morphology. Microstructural parameters were directly calculated using software. Micro-CT images were converted to micro-finite element model using meshing technique, and then micro-finite element analysis (FEA) was performed to assess the mechanical property (Young’s modulus) of trabecular bone. The results showed that the ability to explain this variance of Young’s modulus is improved by combining the structural indices with each other. It suggested that assessment of bone microarchitecture should be added as regards detection of osteoporosis and evaluation of the efficacy of drug treatments for osteoporosis.
Non-Destructive Pile Integrity Test Using HWAW Method
Authors: Park Hyung Choon , Kim Dong Soo
Published: March 2009

The evaluation of soundness of pile is very important for safety of super structure. In this
paper, the HWAW(Harmonic Wavelet Analysis of Wave) method is modified and applied to
evaluate soundness of pile non-destructively. The proposed method can evaluate pile integrity such
as pile length, material quality represented by wave velocity and pile end condition which are very
important factors for pile behavior. To verify the applicability of proposed method, the numerical
simulation test using ABAQUS was performed. A model pile was made and the proposed method
was applied to evaluate soundness of model pile. Through numerical simulation and model tests, it
is shown that the HWAW method has good potential of applying in the evaluation of pile integrity.
Limit Loads for Circumferential Cracked Pipe Bends under In-Plane Bending
Authors: Kim Yun Jae , Oh Chang Sik , Park Bo Kyu , Kim Young Il
Published: March 2009

This paper presents limit loads for circumferential cracked pipe bends under in-plane
bending, based on detailed three-dimensional finite element limit analyses. FE analyses are performed
based on elastic-perfectly-plastic materials and the geometrically linear assumption. Both
through-wall cracks and part-through surface cracks (having constant depths) are considered, together
with different crack locations (extrados and intrados). Based on the FE results, closed-form
approximations are proposed for plastic limit loads of pipe bends. It is found that limit loads of pipe
bends are smaller than those of straight pipes, but are close for deep and long cracks.
Evaluation for Toughness Degradation of 2.25Cr-1Mo Steel Using Magnetic Property Measurement Method
Authors: Nahm Seung Hoon , Park Jong Seo , Chung In Hyun , Ryu Kwon Sang , Kim Am Kee
Published: March 2009

Many researchers have been interested in the nondestructive measurement methods for examining the microstructural changes and components damage in order to assure the safe operation of steel structure. It has been recognized that the techniques based on magnetic measurement offered a great potential because of high susceptibility to the change of several metallurgical factors. In this study, the effect of isothermal heat treatments, which simulate the microstructural changes observed in reactor vessel material at the service temperature, on the magnetic properties was investigated. 2.25Cr-1Mo steel specimens with several different kinds of aging were prepared by an isothermal heat treatment at three different temperature levels. Magnetic property such as coercive force was measured. The coercive force at room temperature monotonously increased with the extent of degradation of the material. The correlation between the measured magnetic property and the mechanical properties was studied. In addition, the applicability of magnetic properties measurements to the evaluation for toughness degradation of reactor vessel was discussed.
Experimental Study on the Structural Safety Assessment of the Tilting Bolster Frame
Authors: Kim Jung Seok , Kim Nam Po , Han Seong Ho
Published: March 2009

This study has performed the experimental study to assess the structural safety of a bolster
frame that is applied to the bogie system of Korean tilting train. In order to achieve this goal, firstly,
loading conditions imposed on the bolster frame were investigated. Based on the international
standard and dynamic analysis, the loading conditions were derived. In this study, the dynamic load
cases that consider the carbody tilting effect were established. The structural safety of the bolster
frame was evaluated by static test under these static loads and the fatigue strength was assessed using
Goodman diagram. From the assessment, the bolster frame has satisfied the structural safety. In
addition, fatigue test was carried out up to 1x107cycles under tilting load condition established in this
study. The inspection of fatigue crack using NDT method was conducted at 6x106 and 1x107 cycles.
Long Range Ultrasonic Guided Wave Technique for Inspection of Pipes
Authors: Park Ik Keun , Kim Yong Kwon , Kim Hyun Mook , Song Won Joon , Cho Yong Sang
Published: March 2009

Conventional non-destructive techniques for inspection of weld in pipelines require
significant test time and high cost. In this paper, a study in the application of ultrasonic guided waves
to long range inspection of the pipeline is presented. The characteristics and setup of a long range
guided wave inspection system and experimental results in pipes of various diameters are introduced.
The experimental results in mock-up pipes with cluster type defects show that the limit of detectable
wall thickness reduction with this guided wave system is 2~3% in the pipe cross section area and the
wall thickness reduction of 5% in cross section area can be detected when actual detection level is
used. Therefore, the applicability of the ultrasonic guided wave technique to long range pipeline
inspection for wall thickness reduction is verified.
Ultrasonic Guided-Wave Mode Identification in Pipe by Using Air-Coupled Transducer and Time-Frequency Analysis
Authors: Park Ik Keun , Kim Hyun Mook , Kim Yong Kwon , Cho Yong Sang
Published: March 2009

For efficient NDE of pipes, essential components of power plant facilities, ultrasonic
guided waves were generated and received applying an air-coupled transducer and comb one as
non-contact technology. Mode generation and selection were predicted based on theoretical
dispersive curve and the element space of a comb transducer. In addition, a receiving angle of the
air-coupled transducer was determined to acquire the predicted modes by theoretical phase velocity of
each mode. Theoretical dispersive curve was compared with the results of the time-frequency
spectroscopes based on the wavelet transform and 2D-FFT to identify the characteristics of the
received mode. The received modes show a good agreement with the predicted ones.
Far IR Emission and Thermal Properties of Ceramics Coated Fabrics by IR Thermography
Authors: Park Chung Hee , Shim Myoung Hee , Shim Huen Sup
Published: March 2009

The purpose of this study was to develop the warm-up suit that is comfortable as well as
has good thermal performance. The function of warm-up suit is to keep the body warm and thus to
lose it’s weight by sweating. Ceramic powders, such as zirconium and magnesium oxide have been
incorporated into the textile structures to utilize the far infrared radiation effect of ceramics, which
heat substrates homogeneously by activating molecular motion. Thermal manikin tests were
conducted to determine the clothing insulation and evaporative resistance of the selected warm-up
suits. Also, the far IR emission effects of ceramics containing laminate on the body heat transfer
were evaluated with the thermogram data using IR camera. The results showed that the ceramics
inside laminate slightly increased the thermal insulation and the evaporative resistance.
Thermogram showed that when the fabric was heated with the thermal manikin, surface mean
temperatures of fabrics were increased as the ceramic incorporated, and the heat storage
performance was confirmed.
Thermal Shock Damage and Mechanical Property of MoSi2 Materials by NDE Technique
Authors: Lee Sang Ll , Kim Young Ho , Shin Yun Seok , Lee Jin Kyu , Lee Joon Hyun , Park Jun Young
Published: March 2009

The mechanical property of sintered MoSi2 materials has been investigated, based on the detailed examination of their microstructures. The nondestructive technique by an ultrasonic wave was also used for evaluating the damage behaviors of MoSi2 materials suffered from the cyclic thermal shock. MoSi2 materials were sintered at the temperature of 1723 K. The flexural strength of MoSi2 materials gradually decreased with increasing the thermal shock cycle, accompanying the extensive creation of surface cracks. The increase of thermal shock cycles resulted in a great decrease of ultrasonic wave velocity and a linear increase of attenuation coefficient for MoSi2 materials.
Electrospun Nanofiber of Nylon 610/Multi-Walled Carbon Nanotube Composites
Authors: Kang Min Sung , Jin Hyoung Joon
Published: March 2009

Multi-walled carbon nanotubes (MWNTs) were incorporated in electrospun Nylon 610
fibers. The MWNTs used were synthesized by a thermal CVD method. To eliminate metallic catalyst
residues in as synthesized MWNTs, they were treated in HNO3 and HCl. The potential adhesion
between the MWNTs and Nylon 610 was expected by the interaction between the amide group of
Nylon 610 and the oxygen-containing species on the MWNTs such as carboxylic acid group
introduced during the purification step. Contrary to the previous works on electrospinning using a
simple blend of carbon nanotubes with polymeric materials, we incorporated MWNTs as nanoscale
fillers by in-situ interfacial polymerization. We also investigated morphology of the electrospun
Nylon 610 fibers with MWNTs.
A Fracture Based Model for Wear Debris Formation
Authors: Li Qing , Loughran Jeffery , Peng Zhong Xiao , Osborne John
Published: March 2009

Wear is often of definite influence in the service life of mechanical components and has
been recognised as one of the major causes of failure in engineering practice. It is noted that
although extensive attention has been paid to phenomenological studies like surface morphology
analysis for wear assessment, the physical mechanism of wear particle formation remains unclear.
This paper proposes a micro damage and fracture model to simulate the process of wear particle
generation. An explicit finite element (FE) formulation is employed to capture the nonlinearities
involved. Unlike existing FE analysis (FEA), any initial sub-fractures underlying the wear surface
are no longer required. Crack initiation and propagation as well as the corresponding mesh updating
are implemented in an automatic fashion associated with the explicit FE framework. The results
presented are in good agreement with experimental observation and the reports in existing literature.
Comparison of Mechanical Properties of the 32CrMoV12-28 Hot Work Tool Steels Alloyed with WC, VC and TaC Powder Using HPDL Laser
Authors: Dobrzański Leszek Adam , Labisz Krzysztof , Klimpel Andrzej
Published: March 2009

This work presents the investigation results of laser remelting and alloying especially the laser parameters and its influence on the structure and properties of the surface of the 32CrMoV12-28 hot work steel, using the high power diode laser (HPDL). As a result structure changes in form of fragmentation were determined. The reason of this work was to determine the optimal laser treatment parameters, particularly the laser power to achieve good layer hardness for protection of this hot work tool steel from losing their work stability and to make the tool surface more resistant to action in hard conditions. For alloying the tantalum carbide, tungsten carbide and vanadium carbide powders were used. For investigations hardness measurements of the different remelting areas were performed. The remelted layers which were formed in the surface of investigated hot work steel were examined metallographically and analyzed using light and electron microscope. Three phases of carbides, TaC, VC and WC, were observed.
Crack Propagation under Compressive Stress Influenced by Crack Face Asperity
Authors: Saimoto Akihide , Toyoda A. , Imai Y.
Published: March 2009

The influence of surface roughness in crack face on the behavior of crack growth is studied. Numerical results derived from two kinds of mechanical models representing the macroscopic and microscopic asperity supposed to exist in the face of an initial crack are compared. In macro-asperity model, the influence of location and size of single-triangular asperity on the stress intensity factor is evaluated. In this model, it is found that the mode-I stress singularity appears in certain circumstances even under overall compression. In micro-asperity model, influence of friction coefficient on the trajectory of crack path is discussed. There exists a tendency that a path of wing crack growth becomes more straight and parallel to axis of compression as the friction coefficient increases.
Damage Detection Based on ESPI and SVM
Authors: Liu Long , Meng Guang , Huang Hai
Published: March 2009

An approach of damage detection based on ESPI and SVM is proposed. ESPI (Electronic
Speckle Pattern Interferometry) is a non-contacting measuring method, which can measure the small
static and dynamitic surface deformations and reveal the flaws by looking for flaw-induced
deformation anomalies. Support Vector Machine (SVM) is a machine learning algorithm based on
statistical learning theory, and it has recently been established as a powerful tool for classification and
regression problems. To develop the precision of processing the pattern fringe data, the SVM is
introduced to process the patterns corrupted by the laser speckle effect. The SVM is trained with
fringe patterns generated from a finite element model and a simple model of the laser speckle effect.
The output pattern is obtained to flag whether the damage exists or not. The trained SVM is tested
for robustness with model generated test patterns of a flat plate. The results show that this approach is
a promising and effective for damage detection.
Low Temperature Explosion for Nanometer Active Materials
Authors: Xie Xing Hua , Li Xiao Jie , Yan Shi Long , Wang Meng , Xu Ming , Ma Zhi Gang , Liu Hui , Guo Zi Ru
Published: March 2009

This paper describes a new method for prediction of the Chapman–Jouguet detonation parameters of CaHbNcOdLieMnf explosives for mixture of some of low temperature explosion explosives at 0 = 1000 kg/m3. Explosion temperatures of water-gel explosives and explosive formulations are predicted using thermochemistry information. The methodology assumes that the heat of detonation of an explosive compound of products composition H2O–CO2–CO–Li2O–MnO2–Mn2O3 can be approximated as the difference between the heats of formation of the detonation products and that of the explosive, divided by the formula weight of the explosive. For the calculations in which the first set of decomposition products is assumed, predicted temperatures of explosion of water-gel explosives with the product H2O in the gas phase have a deviation of 153.29 K from results with the product H2O in the liquid state. Lithium and manganese oxides have been prepared by the explosion of water-gel explosives of the metal nitrates, M (NO3) x (M = Li, Mn) as oxidizers and glycol as fuels, at relative low temperature. We have also used the Dulong-Petit’s values of the specific heat for liquid phase H2O. Lithium manganese oxide powders with chrysanthemum-like morphology secondary particles, but with smaller primary particles of diameters from 5 to 30 nm and a variety of morphologies were found. The oxides produced by this cheap method affirmed the validity of explosion synthesis of nano-size materials for lithium ion batteries.
Study on Phase Transformation Constitutive Behaviors of Shape Memory Alloy
Authors: Zhou Bo , Yoon Sung Ho
Published: March 2009

Phase transformation temperatures of the SMA annealed at different annealing temperature were investigated through a series of DSC test. A new phase transformation model was proposed to predict the phase transformation and a numerical analysis was conducted to demonstrate the applicability of the new model. According to the result, phase transformation temperatures would be affected on annealing temperatures and the new phase transformation model would be applicable to predict the phase transformation under the stress-free state or the external stress state.
Investigation of Fracture Design for Bi-Steel Materials
Authors: Li You Tang , Ma Ping , Yan Chang Feng
Published: March 2009

The eigen-equation of bi-materials cracks was founded on the basis of the stress field and displacement field. The influence of shearing modulus and Poisson’s ratio of matrix material and additive material to eigen-values were analyzed through the results of calculating. The stress intensity factors at the tip of matrix crack were calculated. The suitable parameters of bi-steel materials crack in fracture design were obtained. The results show that the effect of Poisson’s ratio on eigen-values is not obviously and the effect of shearing modulus is obviously. The shearing modulus of additive material should bigger than that of matrix material.
Failure Process of Rock Sample Observed by AE Source Locating Technique under Uniaxial Compression
Authors: Li Yuan Hui , Yuan Rui Fu , Zhao Xing Dong
Published: March 2009

A series of uniaxial-compression tests were conducted on some representative brittle rock specimens, such as granite, marble and dolerite. A multi-channel, high-speed AE signal acquiring and analyzing system was employed to acquire and record the characteristics of AE events and demonstrate the temporal and spatial distribution of these events during the rupture-brewing process. The test result showed that in the primary stage, many low amplitude AE events were developed rapidly and distributed randomly throughout the entire specimens. In the second stage, the number of AE increased much slower than that in the first stage, while the amplitude of most AE events became greater. Contrarily to the primary stage, AE events clustered in the middle area of the specimen and distributed vertically conformed to the orientation of compression. The most distinct characteristic of this stage was a vacant gap formed approximately in the central part of the specimen. In the last stage, the number of AE events increased sharply and their magnitude increased accordingly. The final failure location coincidently inhabited the aforementioned gap. The main conclusion is that most macrocracks are developed from the surrounding microcracks existed earlier and their positions occupy the earlier formed gaps, and the AE activity usually becomes quite acute before the main rupture occurs.
A New Method for Parameters Estimation of Probabilistic Fatigue Crack Growth Rate Model
Authors: Yang Bing , Zhao Yong Xiang
Published: March 2009

A new method is proposed to estimate the parameters of probabilistic fatigue crack growth
rate models, including the Paris equation and its’ improved type. To take the statistical characteristics
of whole test data into account, the method inherits the idea from the general maximum likelihood
method which is widely used in parameters estimation of fatigue S-N curves, ε-N curves, and
da/dN-"K curves, and extends the conventional correlation coefficient optimization method into
parameters evaluation not only for mean curve, but also for standard deviation curve and probabilistic
curve. Analysis on the test data of 16MnR steel indicates that present method is available and feasible.
Comparing to the general maximum likelihood method, present method has simpler algorithm, and
can avoid constructing and solving the likelihood function, so it is speedier in calculation.
Study on Compound Type Crack Propagation Behavior of Asphalt Concrete
Authors: Xie Tao , Qiu Yan Jun , Jiang Ze Zhong , Al Chang Fa
Published: March 2009

The furthest dangerous cracking type of asphalt pavement is usually considered of the
simplex type crack(namely shear crack) under traffic load, but the so-called type crack should
be the compound cracking at the concurrence of I type crack (namely splay crack) and type
crack. In order to study the compound type crack propagation behavior of asphalt concrete, a three
point bending beam with compound type notched has been designed. Asymmetry-gap small girder
specimens of asphalt concrete are adopted in the test, and the central testing equipment is MTS. A
series of compound type three point bending beam tests have been performed to simulate compound
type crack initiation and growth. The propagation of compound type crack is studied by a newly
developed numerical code, Rock Failure Process Analysis (RFPA2D).it is shown that the crack
initiation angle and the peak load increased as the distance of the preexisting crack from the
midpoint of the beam increased, the crack propagation path follows some regularity in general and
the main force of crack propagation is still tensile stress. Through this work, the understanding of
the mechanism about damage and early destroy of asphalt pavement can be advanced and it can
provide guidance for asphalt pavement design and maintenance.
Surface Stress Evaluation from Indentation Load-Depth Curves
Authors: Wang Q. , Ozaki Kimihiro
Published: March 2009

In this work, we investigated the influences of residual stress on the load shifts, irreversible work from load vs. depth curves. It is found that there are linear relationships between the level of surface residual stress, the load shifts, and the variation of irreversible work for Ni, Ti, TiFe and A316L studied in this work. From these effects of residual stresses on load versus depth curves, depth-sensing indentation can be expected as a non-destructive method for measuring the residual stresses. Using the simulation results, the stresses estimated from the relationship of the level of surface residual stress and the load shifts, agree well with the applied stresses during simulations.
A New Grinding Method for Large-Scale Surface of Revolution and Error Analyzing of Its Wheel Dressing
Authors: Yan Qiu Sheng , Zhou Xu Guang , He B.Q. , Kong Ling Ye
Published: March 2009

Large-scale surface such as mould should have low roughness as well as high accuracy of
geometry profile. And it is an essential method to reach the accuracy request with grinding process.
In this research, due to the variety of geometry profiles, an Arc Envelope Grinding Method (AEGM)
is presented, the difficult problem of grinding large-scale revolution surface can be solved.
Meanwhile, the grinding wheel dressing and its shape precision are the keys to the precision of
revolution surface in the grinding with AEGM. In this paper, the influences of setting error of
diamond point dresser, which dress the grinding wheel into an arc section by using numerical
control function of NC grinding machine, upon the shape accuracy of plate-shaped grinding are
analyzed. It is shown that shape error of the grinding wheel increases with the increases of dresser
setting error in diameter direction, radius of tip arc on the grinding wheel, while it reduces with the
increase of radius of the grinding wheel, and shape error distributes no uniformly but symmetrically
along axial direction.
A Study on the Mechanism of the Electrolytic In-Process Dressing (ELID) Grinding Using Molecular Dynamics (MD) & Finite Element (FE)
Authors: Ren Cheng Zu , Guo X.J. , Yuan Li Wei
Published: March 2009

In the paper, the Molecular Dynamics (MD) simulation model and the Finite Element
(FE) analysis model were combined together to study the mechanism of the Electrolytic In-process
Dressing (ELID) grinding. A 3-D MD simulation model for grinding monocrystalline silicon was
established to acquire grinding force and its change laws, and an interpolation multinomial of
grinding force was established on the basis of MD simulation result. A FE model for abrasives and
the passivation film was established to calculate displacement of abrasives in the passivation film.
The grinding force and abrasives displacement were iterated between MD simulation model and FE
analysis model to obtain the displacement variation of the abrasives in the passivation film. The
simulation result shows that, the uniform height of the abrasives in the contour of the grinding
wheel is improved owing to the existence of passivation film in ELID grinding, it is related to the
thickness of the passivation film, and processing quality in ELID grinding could be enhanced
through controlling of thickness of the passivation film.
Implementation of Thermal Models in Grinding
Authors: Morgan Michael N. , Rowe W.B.
Published: March 2009

A thermal model has been implemented in industrial operations where reliability and robustness are important. To fully exploit the potential and usefulness of the thermal model it is necessary to tune the model to accommodate a wide range of wheel / workpiece combinations whilst also satisfying different quality criteria. Implementation is relatively simple and thermal damage to the workpiece can be avoided in most grinding operations. The monitoring process can also be used to aid in optimising dressing intervals or as a tool to identify deteriorating conditions. It is important to understand how to develop and implement strategies to satisfy different user needs. This paper reports on issues associated with tuning the model. Guidance is provided to assist with implementation of the thermal model either as a stand alone monitoring tool or as a fully integrated embedded feature of an intelligent control system. The paper has been prepared in response to queries on this matter from industrial practitioners.
Experimental Study on New Bonding Materials for Developing Nano-Grinding Plates
Authors: Peng Wei , Yao C.Y. , Lv Xun , Liu F.Q. , Gao Tao , Yuan Ju Long
Published: March 2009

This paper describes a method for experimental development of a novel fixed abrasive nano-grinding plate (FAG-plate) which is proposed for lapping some rigid brittle materials, such as quartz crystal and silicon. The FAG plate is developed with ultraviolet-cured resin by rapid prototyping technology. The analysis shows that such FAG-plate can keep its grinding ability constant and continuous and it can make the roughness of machined surface reach to nanometer level. Based on experimental comparisons with conventional free abrasive slurry lapping plates, the lapping process using FAG-plate has several distinct advantages. One is that the machining efficiency is significantly improved. The second is that it improves the surface roughness of machined work-pieces, although it decreases the flatness tolerance of materials. Furthermore, the fixed abrasive nano-grinding plate is made by the new bonding materials- ultraviolet curing resin and thus the fabrication of FAG-plate is convenient and economical.
Non-Traditional Forming Process of Sheet Metal Based on Laser Shock Waves
Authors: Zhou Jian Zhong , Liu Hui Xia , Yang Chao Jun , Cao Xiang Guang , Du Jian Jun , Ni M.X.
Published: March 2009

Traditional forming process of sheet metal is realized with Die and Mould, this technique lacks flexibility and used in the Volume production. The forming process of sheet metal based on laser shock waves is a novel and developing technique. Laser shock forming (LSF) and Laser peen forming (LPF) are two different forming process of sheet metal, both of them are based on a mechanical effect of shock waves induced by laser. In this paper, after introducing the mechanism of laser shock wave generating, these two forming process and technique feature are analyzed and compared, some research progresses are presented. It is indicated that forming technique based on laser shock waves are of high-flexible and great potential application in the fields of plastic forming of sheet metal.
The Analysis of Focused Ion Beam Processing Characteristics for Micro Mold Fabrication
Authors: Choi Hon Jong , Kang E.G. , Hong W.P. , Lee Seok Woo , Choi Young Jae
Published: March 2009

FIB equipment has the ability to perform etching and chemical vapor deposition
simultaneously. It is very advantageously used to fabricate micro structure components having 3D
shape because it has a minimum beam size of Φ 10nm and smaller. Currently, FIB technology has
been studied the research fields relating to two problems such as low accuracy and low productivity
due to redeposition and a charging effect.
This paper focuses on applying FIB technology to the field of micro mold fabrication and repair. As
such, the simple micro pattern fabrication techniques and the experimental characteristics are
studied on FIB-CVD according to ion beam condition and scanning area.
We have encountered some remarks that the result of the experiments according to beam current of
8 pA, shows superior CVD yield. But the result of 1318 pA shows the pattern etched off.
Furthermore, we also analyzed the scanning area effect for FIB-CVD yield and suggest the
maximum yield condition of the chemical vapor deposition for micro part fabrication.
Active Braze Coated Diamond (ABCD)
Authors: Sung James C. , Hu Shao Chung , Chang Yen Shuo
Published: March 2009

The thick braze alloy coating can hold diamond much firmer than thin element coatings
(Ti, Cr, Si) of commercial saw diamond grits. Moreover, the braze alloy can form metallurgical
bonding readily with the metal matrix of saw segments. As a result, diamond saws that employ
ABCD can cut much faster and last much longer than conventional designs.
ABCD can be planted in metal matrix to form three dimensional pattern, the chemical bonding
of diamond and its controlled spacing can virtually eliminate diamond loss due to pullouts and
diamond breakage due to excessive impact force. The greatly increased number of working
crystals can extend the segment life by one order of magnitude.
With the thick coating, ABCD can join together to form needles or plates that could not be
possible with thinly coated diamond. The ABCD needles or plates can be planted or arranged in a
metal matrix to form a three-dimensional structure. Such unique designs can greatly expand the
functions of diamond saws.
Experimental Studies on Grinding of Titanium Alloy with SG Wheels
Authors: Zhang H.X. , Chen Wu Yi , Chen Z.T.
Published: March 2009

The grinding process has been investigated in the machining of titanium alloy with
conventional grinding wheel and SG grinding wheel respectively. The machinability discussed here
includes grinding force, surface roughness, dimensional accuracy, grinding ratio, grinding-wheel
wear and grinding-wheel life. The SG grinding wheel is found to possess particularly good grinding
properties and is more suitable for grinding titanium alloy when compared with conventional
abrasive tools.
Preparation of Hydroxyapatite/Poly(ε-caprolactone) Hybrid Microspheres for Drug Release System
Authors: Zhang Shu Hua , Wang Ying Jun , Wei Kun , Wang Xu Dong
Published: March 2009

Hydroxyapatite(HA) nanoparticles with hydrophobic surface have been synthesized
using mono-alkyl phosphate (MAP) as modifier by hydrothermal synthesis method. The
drug-loaded nano-HA/ Poly(ε-caprolactone)（PCL）composite microspheres and drug-load PCL
microspheres were fabricated by an S/O/W emulsion solvent evaporation method. The microspheres
morphology was investigated by scanning electron microscopy (SEM). Drug distribution in
microsphere matrix was studied by confocal laser scanning microscope (CLSM). The results
showed that the drug distributed evenly in the drug-HA-PCL microspheres, but only around the
surface of the drug-PCL microspheres. The drug release profile showed that the nano-HA/PCL
hybrid microspheres had low initial burst and could release continually for 90 days. This kind of
hybrid microspheres can be used as a promising long-term drug delivery system in the bone.
Repair of Articular Cartilage Defect with Cell-Loaded Nano-HA/PLGA Composites
Authors: Lu H. , Zhang S.M. , Cheng L. , Chen P.P. , Zhou W. , Liu Jian , Zhou J.X.
Published: March 2009

A novel porous composite scaffold of nano-HA/poly (lactic-co-glycolic) (PLGA) was
fabricated by solvent casting/particulate leaching method. Chondrocytes were isolated from the
knee articular joints of a rabbit, and then seeded in the scaffolds. The cell-loaded scaffolds were
cultured in vitro for 5 days before implantation. Full-thickness articular cartilage defects were
created in rabbits, and filled with and without the cell-loaded nano-HA/PLGA scaffolds. The
implants were harvested after in vivo incubation of 2 and 5 weeks. Cartilaginous tissues were
observed at defects repaired with the cell-loaded scaffolds, while only fibrous tissues were found
for the control groups. The repaired tissues were evaluated histologically by hematoxylin and eosin
staining. Results revealed that nano-HA/PLGA composite scaffolds facilitated adheration of cells in
vitro, and the nano-HA particles could prevented the scaffolds from collapsing and promoted the
formation of cartilaginous tissue in vivo.