bluuebunny/crossref_metadata_2025 huggingface dataset:
Protuberant Morphology of Electrospun Polymeric Fibers
Authors: Kang Min Sung , Park Won Il , Jung Rira , Jin Hyoung Joon
Published: March 2009

A highly concentrated solution of polystyrene (PS) in N,N-dimethyl formamide (DMF)
was electrospun and the surface morphology of the electrospun PS fibers was investigated. Unlike
the porous morphology observed on the surface of the fibers electrospun from the PS solution in a
volatile solvent, e.g. tetrahydrofuran, a regular protuberance morphology was found on the surface
of the fibers electrospun from the PS solution in the non-volatile solvent, DMF. This unique surface
morphology was formed due to the presence of residual DMF solvent inside the electrospun PS
fiber. Due to the large diameter of the PS fibers (~5 to ~10 μm) formed from the highly viscous PS
solution, the DMF could not evaporate completely from inside them during the electrospinning
process. Therefore, the extrusive force of the residual solvent inside the fiber induced the formation
of a unique surface morphology. We believe that this unique surface morphology increases the
surface area of the electrospun fibers, thus making it possible to control their wetting or adsorption
behavior.
Elastic and Plastic Mechanical Properties Determined by Nanoindentation and Numerical Simulation at Mesoscale
Authors: Chen Feng Yuan , Chang Rwei Ching
Published: March 2009

This work presents a comparison of numerical simulation and experiment of
nanoindentation testing. A commercial finite element code ANSYS is adopted in the numerical
simulation, in which elastic-plastic properties are considered. A PMMA specimen and a three side
pyramidal Berkovich probe tip is used in the indentation tests. While the elastic-linear workhardening
properties are adopted, the numerical results agree well with the experimental data for
different indentation loads. It proves the numerical simulation can be used in the small scale
analysis.
Static and Dynamic Deformation Measurements of Micro Beams by the Technique of Digital Image Correlation
Authors: He Xiao Yuan , Sun Wei , Zheng Xiang , Nie Meng
Published: March 2009

It is critical to measure the static and dynamic deformation of the micro beam over their
full range of voltage and frequency inputs, which are key parameters for predicting device behavior.
In this study, full-field technique by correlation of projected fringe patterns is selected to determine
static deformation, while dynamic parameters can be obtained by DIC with high-speed CMOS
camera, whose maximal frame rate is 32k f/s. The static tests of micro beams are carried out by
applying electric field forces under different dc voltage, while the dynamic tests are excited by
harmonic excitations. Using the DIC method, the whole field in-plane or out-of-plane displacements
of the micro beams are obtained, and hence the dynamic characteristics by post-processing of
vibration analysis. Experimental results including the bending deformation and vibration parameters
are reported and compared with finite element method. This study verifies the feasibility of this
technique to measure both static and dynamic characteristics of MEMS components.
Yield Property Characterization for Au and TiN Thin Films by Applying Nanoindentation Technique
Authors: Lee Yun Hee , Huh Yong Hak , Kim Ju Young , Nahm Seung Hoon , Jang Jae Il , Kwon Dong Il
Published: March 2009

We tried to apply the nanoindentation technique to yield strength characterization by
modifying a previous research. Although the yield strength determining technique developed by
Kramer et al. has been successfully demonstrated for large scale indentations on bulky metals, its
applicability is still doubtful to nanoscale indentations on thin films with severe roughness,
anisotropy, and interfacial constraint. In order to overcome these problems, we combined the
nanoindentation technique with a three-dimensional indent visualization technique in this study.
Nanoindentation tests were performed for Au and TiN thin films and their corresponding indents
were scanned by using an atomic force microscope. From the three-dimensional pile-up
morphology, a circular pile-up boundary was measured and input into the yield strength formulation
as an effective yielded zone radius. The yield strengths calculated were directly compared with
those from the microtensile test.
Residual Stress Measurement of Porous Silicon Thin Film by Substrate Curvature Method
Authors: Di Yu Xian , Ji Xin Hua , Hu Ming , Qin Yu Wen , Chen Jin Long
Published: March 2009

Extensive research has been done on porous silicon (PS) and its applications in
optoelectronics since the discovery of its light emitting properties. Porous silicon technology is also
used for silicon micro machining. However, porous films can be seriously strained and this often
causes mechanical curling, fracture and device failures. In the present study an optical apparatus
based on substrate curvature method was developed for intrinsic stress measurement of thin films,
which offered a lot of advantages as overall field, non-contact, high precision, nondestructive, easy
operation and quick response. Using the apparatus, the residual stress in porous silicon layers
prepared by electrochemical etching was obtained. The residual stresses in the films were
determined by measuring the curvature of the Si substrate before and after etching. It is found that
the residual tensile stress tends to increase with the porosity increasing and the doping concentration
of the silicon wafer increasing. The results show that there is a deep connection between the microstructure
PS and the residual stress distribution.
Dielectrophoresis of Microparticles with Planar Microelectrode Systems
Authors: Chen Da Feng , Du He Jun , Li Wei Hua , Gong Hai Qing
Published: March 2009

In this paper, the behavior of microparticles subjected to the AC electric fields generated
by planar microelectrode systems is studied. Microelectrodes including interdigitated array,
castellated array, and jagged array are constructed using microfabrication techniques. Micron-sized
latex beads are used to study their movements. Positive and negative dielectrophoresis (DEP) are
studied. In the interdigitated electrodes, particles experiencing n-DEP are levitated stably to certain
heights where the vertical DEP force is balanced by the gravitational force. The levitation heights of
the particles are measured using the consecutively focusing method. The results provide significant
instructions for the dielectrophoretic manipulation and separation of bioparticles.
Thermal Transport Properties of Various Thin Films for MEMS Applications
Authors: Choi Sun Rock , Kim Dong Sik , Choa Sung Hoon
Published: March 2009

The thermal properties of thin films, such as thermal conductivity and diffusivity, are
important in design and analysis of MEMS (micro electro mechanical systems), particularly in
microscale thermal systems and high-power electronic/optoelectronic devices. In the present study,
the thermal conductivity and diffusivity of a variety of thin film materials, which are commonly
used in MEMS applications, are measured. The samples include Au, Sn, Mo, Al/Ti alloy, AlN, and
SiC. The Au sample is deposited by the e-beam evaporation technique while the rest of the metallic
samples are deposited by sputtering processes. The AlN and SiC films are also prepared by
sputtering processes. In the experiment, the thermal diffusivities of metallic thin films are measured
by two independent methods — the AC calorimetric method and photothermal mirage technique.
The thermal conductivities of dielectric thin films are measured by the 3 omega technique. The
results show that the thermal transport properties of some of the films are significantly smaller than
those of the same material in bulk form. Especially, the AlN and SiC thin films exhibit pronounced
thermal conductivity reduction because of the size effect. The electrical conductivities of the
metallic thin films are measured as well. The results for Au and Sn are consistent with the thermal
conductivity, confirming the Wiedmann-Franz law. However, Al/Ti and Mo thin films show
considerable deviation from the law. The results are analyzed based on the XRD (X-Ray
diffraction) and AFM (Atomic Force Microscope) measurement.
Surface Modification Effect of Wettability on the Performance of PDMS-Based Valveless Micropump
Authors: Cho Woong , Ko Yong Jun , Ahn Yoo Min , Yoon Joon Yong , Cho Nahm Gyoo
Published: March 2009

Experimental investigation and numerical simulation on the effect of surface wettability
on the performance of a polydimethylsiloxane (PDMS) based diffuser micropump are presented. A
valveless micro membrane pump with piezoelectric actuation has been examined. Using a replica
molding technique, the valveless micropump was made of PDMS on a Pyrex glass substrate. A thin
piezoelectric (PZT) disc was used as an actuator. Poly vinyl alcohol (PVA) and
octadecyltrichlorosilane (OTS) coatings, which make the coated surface hydrophilic and
hydrophobic, respectively, were used to modify the surface wettability inside the pump. In our
experiments, the contact angle of the PDMS surface changed from 96.6 o to 29.1 o and 99.6 o by
PVA and OTS coatings, respectively, and the contact angle of glass changed from 33.2 o to 17.5 o
and 141.8 o. A self-priming process was numerically simulated in a diffuser element using a
computational fluid dynamics program (CFD-ACE+). The results show that fewer gas bubbles were
created in the hydrophilic coated pump than in the hydrophobic coated one as time progressed. This
agrees well with experimental observations. Steady-state flow rates of the micropump were
measured. Compared to the non-coated pump, the flow rate increased slightly with the hydrophobic
coating but decreased with the hydrophilic coating. We determine that surface wettability
significantly affects the performance of a PDMS-based micropump.
Explicit Time Integration Algorithm for Fully Flexible Cell Molecular Dynamics
Authors: Park Shi Dong , Cho Maeng Hyo
Published: March 2009

Fully flexible cell with Nose-Poincare method preserves Hamiltonian in structure, so the
extended Hamiltonian is preserved in the real time domain. In the previous development of Nose-
Poincare method for NVT, NPT, and NT ensemble unit cell simulations, implicit algorithm such
as generalized leapfrog integration scheme was used. The formulation and numerical implementatio
n of the implicit formula is much more complicated because it includes nonlinear iteration procedur
e. Furthermore, it is not easy to show time reversibility in implicit formula. Thus for these reasons,
it is necessary to develop explicit formula in MD unit cell simulation. We develop fully flexible
explicit Nσ T ensemble MD simulation algorithm. It guarantees the preservation of extended Hamil
tonian in real time domain and time reversibility. The numerical implementation is easy and relative
ly simple since it does not require iteration process. It is established by using the splitting time integ
ration. It separates flexible cell Hamiltonian into several terms corresponding to each Hamiltonian
part, so the simple and completely explicit recursion formula was obtained. Unit cell tension, shear
test for bulk material tension and shear tests are performed to demonstrate the validity and
performance of the present explicit molecular dynamics scheme formulated through the spitting
method. We compare the results of the explicit splitting time integration scheme with those of the
implicit generalized leapfrog time integration scheme. The proposed explicit NT unit cell simulati
on method should serve as a powerful tool in the prediction of the material behavior.
In Situ Displacement Measurement of Flex Package Subject to Thermal Shock Conditions
Authors: Yoon Samson , Cho Seung Min , Lee Yuri , Han Bong Tae
Published: March 2009

A unique interferometric system utilizing thermal-conduction loading is developed and
implemented to investigate the effect of ramp rates of accelerated test profiles on the thermal
deformation of flex package assemblies. The system provides extreme ramp rates to simulate the
thermal shock condition with a temperature control much finer than the conventional convection
based system can provide. The in-plane and out-of-plane displacements of the flex package are
documented through moiré interferometry and Twyman/Green interferometry, respectively.
Deformation measured under a thermal shock condition is compared with that under the
conventional thermal cycling condition to assess the effect of ramp rates on package deformation.
The comparison reveals that a low ramp rate of typical accelerated thermal cycling (ATC) tests
causes significant reduction in the maximum level of elastic energy in the package assembly.
Effects of Packaging Induced Stress on MEMS Devices and Its Improvements
Authors: Choa Sung Hoon , Lee Moon Chul , Cho Yong Chul
Published: March 2009

In MEMS, packaging induced stress or stress induced structure deformation becomes
increasing concerns since it directly affects the performance of the device. The conventional MEMS
SOI (silicon-on-insulator) gyroscope, packaged using the anodic bonding at the wafer level and
EMC (epoxy molding compound) molding, has a deformation of MEMS structure caused by
thermal expansion mismatch. Therefore we propose a packaged SiOG (Silicon On Glass) process
technology and more robust spring design.
Experiment Study and Finite Element Analysis of Spring Constant of Welded Metal Bellows
Authors: Piao Chang Hao , Cho Chong Du , Kim Chang Boo , Pang Qiang
Published: March 2009

This study tries to obtain the spring constant of welded metal bellows through
experimental and numerical method respectively. The prediction of spring constant plays a great
role in the design and application of the welded metal bellows. To derive the spring constant of the
bellows, we employ commercial package to build up 2 axi-symmetric FEM models by using plane
42 and shell 51 elements. In the experiment, we use UTM to measure the spring constant of the
bellows. And, the predicted spring constant resulting from the analysis is compared with the
experimental one to discuss the rationality of spring constant analysis. The analytical results
correspond well with experimental data and hence explaining the validity of FEM model.
Analysis of Simultaneous Velocity and Density Distributions for High-Speed CO2 Flow Using Particle Image Velocimetry and Digital Speckle Tomography
Authors: Ko Han Seo , Kim Yong Jae , Kwon Oh Chae , Okamoto Koji
Published: March 2009

Velocity and density distributions of a high-speed and initial CO2 jet flow have been
analyzed simultaneously by a developed three-dimensional digital speckle tomography and a
particle image velocimetry (PIV). Three high-speed cameras have been used for the tomography
and the PIV since a shape of a nozzle for the jet flow is asymmetric and the initial flow is fast and
unsteady. The speckle movements between no flow and CO2 jet flow have been obtained by a
cross-correlation tracking method so that those distances can be transferred to deflection angles of
laser rays for density gradients. The three-dimensional density fields for the high-speed CO2 jet
flow have been reconstructed from the deflection angles by the real-time tomography method, and
the two-dimensional velocity fields have been calculated by the PIV method simultaneously.
On Statistical Properties of High Temperature Creep Rupture Data in STS304 Stainless Steels
Authors: Kim Seon Jin , Kong Yu Sik , Roh Young Jin , Jung Won Taek
Published: March 2009

This paper deals with the statistical properties of short time creep rupture characteristic
values (for example, creep rupture time, steady state creep rate, total creep rate, initial strain, etc.) in
STS304 stainless steels. From short time creep rupture tests performed by constant stresses at three
different elevated temperatures 600, 650 and 700, the scatter and probability distributions were
investigated for rupture time, total creep rate, steady state creep rate, initial strain, and others. The
effect of temperature on the statistical scatter of rupture time was the smallest at 700. The effect
of stress on the statistical scatter of rupture time was smaller with increasing stresses. The
probability distributions of short time creep rupture data were well followed 2-parameter Weibull.
Reliability Evaluation System of Electronics Components
Authors: Lee Seung Woo , Han Seung Woo , Song Jun Yeob , Kim Wan Doo , Lee Hwa Ki
Published: March 2009

The reliability, that is long-term quality, requires a different approaching from short-term
quality which is used before. As the electronic components are to be easily normalized on the
reliability evaluation, many reliability prediction methodologies are used. In this study, integrated
reference model of reliability prediction is serviced for existing PRISM and Bellcore which is
related on reliability prediction about electronic components, and will service reliability data based
on PoF (Physics of Failure) from domestic research center. The constructed frame of reliability
evaluation system, which can predict and evaluate reliability of electronic components and MEMS,
is designed by using online service of the reliability data accumulated on web. To evaluate proposed
system, the reliability evaluation of PCB (Printed Circuits Boards), which is used in NC controller
of machine tools, is introduced according to PRISM, the representative reference model of
reliability prediction about electronic components based on MIL-HDBK-217F.
Reliability Assessment of Systems at the All Stages of Life Cycle
Authors: Soliterman Yuri L. , Berestnev Oleg V. , Goman Aarcady M.
Published: March 2009

The methods of reliability assessment of technical system at the base stages of life cycle,
such as conceptual design, detail design, test, and service are described. The developed by authors
new methods of taking into account the mutual correlation between failure of separated components
of system at reliability evaluation are proposed. The practical examples of employment of described
methods confirm the rationality of their practical use.
Wafer Level Hermetic Packaging for RF-MEMS Devices Using Electroplated Gold Layers
Authors: Park Gil Soo , Yu Ji Hyuk , Seo Sang Won , Choi Woo Beom , Paek Kyeong Kap , Sung Man Young , Park Heung Woo , Yun Sang Kyeong , Ju Byeong Kwon
Published: March 2009

Thermocompression bonding of electroplated gold is a promising technique for achieving
low temperature, wafer level hermetic bonding without the application of an electric field or high
temperature. Silicon wafers were completely bonded at 320 at a pressure of 2.5. The
interconnection between the packaged devices and external terminal did not need metal filling and
was made by gold films deposited on the sidewall of the via-hole. In the hermeticity test, packaged
wafers had the leak rate of 2.74 ± 0.61 × 10-11 Pa m3/s. In the result of application in packaging of
FBAR filter, the insertion loss is increased from -0.75dB to -1.09dB at 1.9.
A Simple Phase Unwrapping Approach Based on Filtering by Windowed Fourier Transform (II)
Authors: Kemao Qian , Soon Seah Hock
Published: March 2009

Phase unwrapping is an important and challenging process in optical interferometry.
Difficulties in phase unwrapping are usually caused by either noise (“bad” pixels) or invalid areas
(“bad” regions). If the “bad” pixels can be removed, the problems due to the noise are solved.
Further, if the “bad” regions can be identified, they can be avoided in phase unwrapping. In our
previous work the noise can be successfully removed using a windowed Fourier transform [Optics
and Lasers Technology, 37:458-462 (2005)]. In this paper we will show that the invalid areas can be
identified by the same windowed Fourier transform. Thus a single windowed Fourier transform is
able to process both “bad” pixels and “bad” regions simultaneously, which makes the phase
unwrapping simple and effective.
Development of Combined Optical System for Thermal Analysis of Impinging Flames
Authors: Ko H.S. , Ahn S.S. , Baek S.H. , Kim Tae Sung
Published: March 2009

Three-dimensional density distributions of an impinging and eccentric flame have been
analyzed numerically and experimentally by a combined optical system with a digital speckle
tomography. The flame has been ignited by premixed butane/air from air holes and impinged
vertically against a plate located at the upper side of the burner nozzle. In order to compare with
experimental data, computer synthesized phantoms of impinging and eccentric flames have been
derived and reconstructed by a developed three-dimensional multiplicative algebraic reconstruction
technique (MART). A new scanning technique has been developed for the analysis of speckle
displacements to investigate wall jet regions of the impinging flame including sharp variation of the
flow direction and pressure gradient. The reconstructed temperatures by the digital speckle
tomography have been compared with a temperature photography by an infrared camera and results
of a numerical analysis using a finite element method.
Experimental Study of Stress Behavior under High Temperature Using New Device by Photoelasticity Methods
Authors: Sasakir Syuutei , Ezumie Tsutomu
Published: March 2009

In recent society, the lap joint that is one of the joint techniques in the industrial society is used for
the purpose of joint with the material and the material or the material and the metal and dissimilar
materials. We are given the favor in the daily life for the merchandise, the tool and the other goods.
The studies of concerning of the lap joint such as the analysis of the surface for the adhesive and the
adherent are reported. There is much report about the FEM, but the experimental analysis is not
much. Especially, the thermal stress analysis of the lap joint is reported a few. These are almost
about the FEM methods, but the report of the thermal analysis is few. The authors think that the
experimental analysis is not enough about the study of the thermal analysis and tried to experiment
the stress of the adherent. Therefore the authors tried to analyze using the photoelasticity methods.
The authors made for the device to analyze the under same temperature of around the circumstance.
This new device keeps the temperature constantly; the adhesive and the adherent are keeping in this
device. This was observed the variation of the stress under constant temperature. It was obtained the
result that the stress of the adhesive joint was influenced about the heat.
Three-Dimensional Microfabrication System for Scaffolds in Tissue Engineering
Authors: Lee Seung Jae , Kim Byung , Lee Jin Sang , Kim Sung Won , Kim Min Soo , Kim Joo Sung , Lim Geun Bae , Cho Dong Woo
Published: March 2009

Understanding chondrocyte behavior inside complex, three-dimensional environments
with controlled patterning of geometrical factors would provide significant insights into the basic
biology of tissue regenerations. One of the fundamental limitations in studying such behavior has
been the inability to fabricate controlled 3D structures. To overcome this problem, we have
developed a three-dimensional microfabrication system. This system allows fabrication of
predesigned internal architectures and pore size by stacking up the photopolymerized materials.
Photopolymer SL5180 was used as the 3D microfabricated scaffolds. The results demonstrate that
controllable and reproducible inner-architecture can be fabricated. Chondrocytes from human nasal
septum were cultured in 3D scaffolds for cell adhesion behavior. Such 3D scaffolds might provide
effective key factors to study cell behavior in complex environments and could eventually lead to
optimum design of scaffolds in various tissue regenerations such as cartilage, bone, etc. in a near
future.
Human Postural Feedback Response Described by Eigenvector
Authors: Kim Se Young , Park Suk Yung
Published: March 2009

Human postural responses appeared to have stereotyped modality, such as ankle mode,
knee mode, and hip mode in response to various levels of postural challenges. We examined
whether human postural control gain of full-state feedback could be decoupled along with the
eigenvectors. To verify the model, postural responses subjected to fast backward perturbation were
used. Upright posture was modeled as 3-segment inverted pendulum incorporated with linear
feedback control, and joint torques were calculated using inverse dynamics. Postural modalities,
such as ankle, knee and hip mode, were obtained from eigenvectors of biomechanics model. As
oppose to the full-state feedback control, independent modal control assumes that modal control
input is determined by the linear combinations of corresponding modality. We used linear
regression to obtain and compare the feedback gains for both eigenvector control gain and full-state
feedback. As a result, we found that both feedback gains of two control models that fit the joint
torque data are reasonably closed each other especially at the joint angle feedback gains. This
implies that the simple parameterization using eigenvectors may be used to correlate the feedback
gains of full-state feedback control.
A Study on the Stent Expansion Behavior of the Human Artery Based on Finite Element Analysis
Authors: Kim Sung Min , Park Sung Yun
Published: March 2009

In this paper, non-linear interactions between a stent and an artery are analyzed using
the finite element method [ANSYS (Ver 10.0)]. The material property of the artery is assumed to be
hyper-elastic. The loading conditions were applied in three steps, according to the pressure level
(pressure increase, constant load pressure, and pressure decrease). From the results, the maximum
von Mises stresses were measured in the area of contact of the stent and the artery. The maximum
von Mises stresses of the stent and artery were obtained and the increase in the maximum pressure
showed a decrease in the von Mises stress of the stent. The simulated results show that the distal
end of the stent, which tilted after the expansion behavior in the artery, may damage the artery wall.
The finite element model used in this study may help in designing the stent.
Development of a 5-DOF Hybrid Micro-Manipulator and Implementation to Needle Manipulation Process in Medical Applications
Authors: Chung Goo Bong , Chung Jae Heon , Choi Dong Gul , Yi Byung Ju , Han Seok Young , Kim Seon Jung
Published: March 2009

This paper reports the development and preliminary experiments of a robotic system
designed to perform needle manipulation tasks in medical applications. A hybrid type manipulator
is designed to enlarge the workspace without loss of position accuracy. In this paper, we initially
analyze the workspace and step resolution of the robotic system in the operational space. Then, we
perform trajectory tracking experiment to verify that the developed robotic system could be
employed to attenuate an unpredictable tremor of human operators and enhance position accuracy
in neurosurgery or ophthalmic surgery, etc. It is shown through experimentation that the robothuman
cooperation mode is effective for micro-manipulation tasks.
Biomechanical Skin Measurement System for Anlaysis Viscoelasticity
Authors: Kwon H.J. , Kwon Y.H. , Kim Yoon Hyuk
Published: March 2009

We design the biomechanical skin measurement system which is assembled with
multi-components load cell and actuator. The multi-components load cell simultaneously
measures the normal load (Fz), and moniter (Fx, Fy) with strain gages. Capacity and accuracy of
load cell are less than 5 N and 0.1%. In this research, designed measurement system applies to
determine in-vivo viscoelasticity of human skin.
Strain Analysis on Porous TiNi SMA Using SEM Moiré Method
Authors: Du Hua , Xie Hui Min , Jiang Hai Chang , Rong Li Jian , Luo Qi Ang , Gu Chang Zhi , Zhao Ya-Pu
Published: March 2009

In this paper, a new technique for fabricating grating on the surface of porous TiNi SMA
is proposed. The grating is directly written onto the surface of the specimen using the FIB milling.
No photoresist is required during the lithography process. From the experimental results, it can be
obviously seen that the grating fabricated by FIB milling has a better quality than that by electron
beam lithography. Using the self-made FIB grating, the in-plane deformation of the porous TiNi
SMA in microscale is studied by SEM moiré method. Moiré and the microscopical structures are
synchronously observed, including microcracks, martensites and grain boundaries.
Orthogonal Properties of Human Trabecular Bone by Spherical Indentation Test
Authors: Bae Tae Soo , Lee Tae Soo , Choi Kui Won
Published: March 2009

The elastic modulus and the apparent density of the trabecular bone were evaluated from
spherical indentation tests and Computed Tomography and their relationship was quantified. After
the femurs were prepared and embedded with respect to their anatomical orientation, the transverse
planes of the trabecular bone specimens were scanned at 1mm intervals using a CT scanner. The
metaphyseal regions were sectioned with a diamond-blade saw, producing 8mm cubes. Using a
custom-made spherical indentation tester, the cubes were mechanically tested in the anteriorposterior
(AP), medial-lateral (ML), and inferior-superior (IS) directions. After determination of
modulus from the mechanical testing, the apparent densities of the specimens were measured. The
results showed that the IS modulus was significantly greater than both the AP and ML moduli with
the AP modulus greater than the ML modulus. This demonstrated that orthogonality was a
structural characteristic of the trabecular bone. The power relationship between the modulus and the
apparent density was also found to be statistically significant.
Noninvasive Imaging Technique Predicts Failure Load of the Femur with Simulated Osteolytic Defects
Authors: Lee Tae Yong , Snyder Brian D.
Published: March 2009

Objective. To determine whether the load-carrying capacity of human proximal femora with
simulated lytic defects can be predicted using QCT-derived simplified beam theory.
Design. The predicted fracture load of simulated defects were calculated using new technique of QCT
combined with engineering beam analysis.
Patients. Simulated lytic defects were created using a surgical drill in the intertrochanteric region of
twenty human cadaveric femora. QCT scans were conducted before and after creating defects on
either AM (Anterior-Medial) or PL (Posterior-Lateral) regions.
Results. A linear relation could be used to predict failure load from the proposed engineering analysis
based on QCT scan. The coefficient of determination analysis of QCT-derived predicted load vs. the
measured failure load was R2=0.73 (p<0.0001).
Conclusions. The data suggest that three quarters of human femoral failure can be predicted in vivo,
i.e. using QCT scan. Combined with information on the loads associated with the activities of daily
living, these data may be used to prevent pathologic fractures of patients who had prior surgery of
removing tumors on proximal femurs.
Mechanics of Interactions of Helices in Proteins
Authors: Xin Li Li , Chirikjian Gregory S.
Published: March 2009

This paper concerns a mechanics of interactions of helical structures in proteins. Helices
are the most important secondary structures of proteins and contribute the formation of a more
complex 3-D structure, and so the analysis of interactions of helices is quite critical. We examine
1290 protein structures that have 2.0 Å or better resolutions and less than 20 percent of their
sequences in common. Interactions between helices are represented by two parameters: the distance
and angle. Assuming that helices are slender rigid rods with finite length, we define three different
mechanisms of interactions: (1) line-on-line contact; (2) endpoint-to-line contact; and (3) endpointto-
endpoint contact. In this paper, interactions for the first case are expressed with the 3-D relative
rigid-body motion (position and orientation) and the unique volume element for correctly
integrating over rigid-body motions are determined using six parameters. The results are extremely
useful for the correct analysis of interactions in terms of distance and angle without the statistical
biases inherent in the three data sets.
Treatment Performance of Membrane Bioreactor for Organic Acid Fermentation
Authors: Kim Jong Oh , Jung Jong Tae , Choi Won Youl
Published: March 2009

This study focused on the treatment performance of membrane bioreactor (MBR)
coupled with intermittent ozone bubbling for the effective recovery of dissolved organics from
coagulated fresh sewage sludge. Intermittent ozone bubbling was effective in the prevention of
permeation resistance increase caused by particle accumulation on membrane surface, which result
in keeping high permeation flux. MBR with intermittent ozone bubbling is believed to be an
effective system for the recovery of organic matter usefully utilized in biological denitrification as
well as membrane fouling reduction.
Electrical Characteristics of Biological Active Point from Three Electrode Method
Authors: Kim Min Soo , Lee Jin Sang , Kim Pan Kyeom , Lim Geun Bae
Published: March 2009

We anticipate the development of new real time biological active point (BAP) systems
based on skin impedance, since this measurement method has the superior characteristics of
noninvasiveness and easy operation.
In this paper, we report on the three electrode measure method that has the advantage of
measuring the impedance of the BAPs under the skin. This system easily measured the potential
difference between the measurement electrodes and reference electrodes. The BAPs have lower
impedance at all frequencies and their reactance is much smaller than that of the surrounding skin.
The characteristic frequencies of BAPs are about 20-30HZ higher than that of the surrounding skin.
This technology analyzed accurately and objectively the reactance and characteristic frequency of
BAPs.
Quantification of Crack Length and Thickness Effects on J-R Curves by Ductile Damage Models
Authors: Chang Yoon Suk , Lee T.R. , Choi Jae Boong , Seok Chang Sung , Kim Young Jin
Published: March 2009

In this paper, the applicability of local approach is examined for SA515 Gr.60 nuclear
steel through a series of finite element analyses incorporating modified GTN and Rousselier models
as well as fracture toughness tests. To achieve the goal, fracture toughness test data of standard
compact tension (CT) specimens are used for calibration of micro-mechanical parameters. Then,
from finite element analyses employing the calibrated parameters, fracture resistance (J-R) curves
of CT specimens with different crack length to width ratio, with different thickness and
with/without 20% side-grooves are predicted. Finally, suitability of the numerically estimated J-R
curves was verified by comparison with the corresponding experimental J-R curves.
On Fatigue Crack Propagation of One-Way Rail Road
Authors: Farhangdoost Khalil , Kavoosi Mohammad
Published: March 2009

In this paper, the mechanism of fatigue crack propagation of one-way rail road and the
effects of some parameters such as crack length, initial crack angle, contact stress, friction,
hydraulic pressure and crack propagation direction, in fracture toughness are presented so that it can
be used to predict the fatigue life of rail road. The results of stress intensity range factor in one-way
rail road are compared with two-way rail road. It is demonstrated that the crack in one-way growth
faster than two-way rail road.
A Study on the Lower Flanges Fracture of Endplate Bolted Connection
Authors: Ma Hong Wei , Cho Chong Du , Pan Qiang , Beom Hyeon Gyu
Published: March 2009

The quasi-static tests on the endplate bolted connections of the new structure system
consisting of SCC beam and CCSHRC column are briefly introduced in this paper. Meanwhile, the
3-D solid finite element models of the connections with pre-existing cracks in the lower flange’s
high stress fields are set up by ANSYS. The material nonlinearities of concrete, steel and bars,
together with the contact between the endplate and column surface are all considered in the model.
With the transverse load applied on top of columns, the fracture parameters are calculated by APDL.
The results indicate that the opening mode crack will happen mainly. When the pre-existing crack
length is 2.50mm and the inter-storey drift is less than 6mm, the stress intensity factor values agree
well with the converting values derived from J-integral and the crack tip fields are in elastic state.
The J values are highly influenced by the pre-existing crack length, while seldom influenced by the
concrete compression strength. Moreover, the J-integral have the trend to sharply increase when the
pre-existing crack length is larger than 0.61mm, and the pre-existing crack will grow during loading
when its length is larger than 1.35mm.
Nondestructive Detection of Delamination of Thermally Sprayed Material Using ESPI
Authors: Shinhara Yoshiko , Tokuda Tarou , Suzumura Fumihiro , Ohtani K. , Wang Rong Guang , Kido Mitsuo
Published: March 2009

Detection of delamination of a thermally sprayed coating on an SUS304 substrate was
carried out nondestructively using electronic speckle pattern interferometry (ESPI) method in both
static and cyclic tests at T=298 K and 873 K. Results showed that the surface strain of the coating
becomes smaller than that of the substrate when delamination occurs from the interface of the
substrate. Two parameters of critical strain of ε
c and ε
f, which correspond respectively for the static
test and the cyclic test, are introduced to evaluate the existence of delamination according to the
ε- σ
s and ε-N curve. It is considered possible to evaluate the occurrence of delamination in cyclic
tests using the static critical strain of ε
c, instead of ε
f.
Development of Intelligent Grinding Database
Authors: Cai R. , Morgan Michael N.
Published: March 2009

This paper describes the structure, content and relations employed in the development of
an intelligent grinding database. The intelligent database has been constructed in MS Access with
Visual Basic support code. The database was developed as an integral feature of an intelligent
grinding assistant (IGA

). The IGA

has been implemented and evaluated on a cooperating
partners CNC machine tool.
Development of a Resin-Coated Micro Polishing Tool by Plasma CVD Method -Electrorheological Fluid-Assisted Polishing of Tungsten Carbide Micro Aspherical Molding Dies-
Authors: Kaku Tsuyoshi , Yoshihara Nobuhito , Yan Ji Wang , Kuriyagawa Tsunemoto , Abiko Kazuhiko , Mikami Yoshiharu , Noguchi Masahiro
Published: March 2009

The viscosity of an electrorheological fluid (ER fluid) increases with an increase in the
intensity of an electric field. In the case of ER fluid-assisted micro polishing the workpiece needs to
be a conductive material such as tungsten carbide and the gap between the workpiece and the
polishing tool, which both act as electrodes, must be the same size as the abrasive grain. It is difficult
to maintain a small gap when polishing the surface of the workpiece. In order to prevent direct contact
between the workpiece and the polishing tool, a resin-coated polishing tool has been developed. In
this paper, a micro polishing tool was made using a plasma chemical vapor deposition method. The
geometry of the polishing tool was examined by a finite element method (FEM) to optimize the
concentration of the abrasive grains. In polishing machining using the tool, the width of the polishing
groove was 35 μm, and polishing machining in a micro area was achieved.
An Experimental Study of the Polishing Process for MgO Single Crystal Substrate
Authors: Wang Ke , Kang Ren Ke , Jin Zhu Ji , Wang Ning Hui
Published: March 2009

In order to obtain ultra-smooth and damage free substrate surfaces for MgO single-crystal substrate with high polishing efficiency, an experimental investigation based on systemically designed polishing experiments are presented and discussed. Considering the structural characteristics and chemical properties of the MgO single crystal, the experiments use a polishing slurry containing SiO2 abrasives so that the process is performed under a combination of mechanical and chemical actions. The effects of the polishing process parameters, such as polishing pressure, rotational speed of polishing plate, and the flow rate and concentration of the polishing slurry, on the surface roughness and material removal rate (MRR) are analyzed. Finally, a recommendation is made for selecting the appropriate polishing parameters for MgO single crystal substrate, based on which a surface roughness of 0.3nm can be achieved on the MgO substrate in 20min of polishing time.
A Finite Element Analysis of Stress Fields in Vickers Indentation on Brittle Materials
Authors: Zhang Bing , Yoshioka Masato
Published: March 2009

A three dimensional finite element model for Vickers indentations on brittle materials is
presented in order to analyze the stress distribution. The objective of this paper is to study when and
where cracks are most likely to initiate and propagate in the indentation cycle based on the analyzed
stresses. Therefore the time-dependent stresses around and below the surface of the contact area
during the indentation cycle, especially at the end of loading and at the beginning of unloading phase
are investigated in detail. The analytical results are shown to be in good agreement and verified with
the experimental results.
Experimental Research on Surface Integrity of Ceramic Nanocomposites in Two-Dimensional Ultrasonic Vibration Grinding
Authors: Zhao Bo , Wu Yan , Jiao Feng , Gao G.F. , Zhu Xun Sheng
Published: March 2009

The grain cutting trace of elliptical spiral in workpiece two-dimensional ultrasonic
vibration grinding(WTDUVG) is defined, the reason of machining accuracy improvement by
applying two-dimensional ultrasonic vibration is discussed. Adopting two-dimensional ultrasonic
composite processing, the influences of grinding depth, worktable velocity, wheel granularity on the
surface roughness of Al2O3/ZrO2 ceramic nanocomposites were described. Experimental results of
AFM microstructure show that the material removal model in WTDUVG is dominated by ductile
flow of material, some crystal refinement, the crush powder and grain pull-out are visible and there is
almost no fracture. Furthermore, the surface roughness in WTDUVG with coarse grit is about 30
40% less than that in CG under identical grinding condition; the qualitative analysis of X-diffraction
results indicated that the surface phases are composed of α-Al2O3, t-ZrO2 and small quality m-ZrO2,
there are amorphous phase in the surface both with and without vibration grinding. M-zirconia phase
transitions rule in vibration and conventional grinding was found. Under definitive grinding
conditions, the material removal mechanism of inelastic deformation is the principal removal
mechanism of Al2O3/ZrO2 ceramic nanocomposites, the grit size of diamond wheel and vibration
grinding mode have important influence on material removal mechanism of ceramic nanocomposites.
Quantitative Adhesion Measures of Diamond Films Using A Blister Test
Authors: Jian Xiao Gang , Shi L.D. , Chen Ming , Sun Fang Hong
Published: March 2009

Adhesion properties of diamond thin films are essential to their performance in technical
applications. To obtain the adhesive strength precisely and quantitatively has been the frontier issue
to the related scientists and engineers. In this paper, a new experimental equipment for blister tests
was designed purposely and fabricated considering related influencing facts. A free-standing
window of diamond thin film with the support of silicon wafer was obtained by the aid of
photolithography and anisotropic wet etching technology so as to improve the precision of
quantitative adhesion measures of diamond films. The mechanics for calculating the quantitative
driving force of blister-induced delamination of diamond thin film is presented, which is on base of
intensive modeling and simulation. The laser interferometer measurement with fine solution was
used to pick up dynamic signals of diamond thin film bulge deformation in micrometer scale and
the relationship demonstration of stress to strain of the diamond thin film was available, as a
consequence, the adhesive strength could be obtained precisely and quantitatively by the valid
model. The paper confirms the accessibility to precise quantitative adhesion measures of diamond
films and the results will be beneficial to wide application of diamond thin films in the related
fields.
Technique of Brass Spiral Structure Deposition Using Micro EDM in Gas
Authors: Wang Zhen Long , Jin Bai Dong , Cao Guo Hui , Wei Z.W. , Zhao Wan Sheng
Published: March 2009

This paper proposes a new deposition method using micro electrical discharge machining (EDM) to deposit micro spiral structure in gas. First, the basic principles of micro electrical discharge deposition (EDD) are analyzed and the realized conditions are predicted. Then with an ordinary EDM shaping machine, brass as the electrode, high-speed steel as the workpiece, a lot of experiments are carried out on the micro spiral structure deposition in air. The effects of major processing parameters, such as the discharge current, discharge duration, pulse interval, gravity and working medium, are obtained. As a result, a 19-circle micro spiral structure with 0.19mm in external diameter, 0.1mm in wire diameter and 3.39mm in height is deposited. Measurements show that the deposited material has obvious delaminating structure, the components of which depend on those of the tool electrode material, although Zn in the electrode is oxidized to ZnO. This method establishes the research basis for micro three-dimensional deposition machining.
Study on the Application of the Combined Prediction Modeling Method to Thermal Error Modeling on NC Machine Tools
Authors: Li Y.X. , Yang Jian Guo , Li Yu Yao , Zhang H.T. , Turyagyenda G.
Published: March 2009

Due to the complexity of machine tool thermal errors affected by various factors, a new
combining prediction model, based on the theory of gery system GM (1,1) model, is applied to the
trend prediction of machine tool thermal errors. The degree of smoothness of primary data sequence
is first improved by function transform method and sequentially grey system GM (1,1) model is
established; second, time series analysis model is established by remnant sequence of GM (1,1)
model to amend the precision of grey system GM (1,1) model. Thus, the precision of combining
prediction model is further improved. Through the prediction study on thermal error modeling in a
spot NC turning center, testing results showed that combining prediction model can highly improve
machine tool’s prediction precision and make it more effective for real-time compensation of
machine tool thermal error.
Comparison of Osteoinduction by Autologous Bone and Biphasic Calcium Phosphate Ceramic in Goats
Authors: Fellah Borhane H. , Gauthier Olivier , Weiss Pierre , Chappard Daniel , Layrolle Pierre
Published: March 2009

Autologous bone chips are widely used in orthopedic surgery to fill large defects due to
osteoinductive property but are limited in quantity. Several groups have reported the formation of
mineralized bone after implantation of bioceramics in ectopic sites of different animals. However,
osteoinduction by bioceramics has not yet proved to be equivalent to those of autologous bone. In
this study, we compare the bone inducing capability of autologous bone chips and synthetic
biphasic calcium phosphate (BCP) ceramics granules sintered at various temperatures. Both
materials were implanted in muscles and femurs of goats inside hollow containers for 6, 12 and 24
weeks and analyzed by histology. This study showed that bone tissue formed in contact with micro
porous ceramics sintered at low temperature as well as autologous bone chips both in ectopic and
intrafemoral sites of goats.