• Title/Summary/Keyword: Microscopic interface

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A Meshfree procedure for the microscopic analysis of particle-reinforced rubber compounds

  • Wu, C.T.;Koishi, M.
    • Interaction and multiscale mechanics
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    • v.2 no.2
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    • pp.129-151
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    • 2009
  • This paper presents a meshfree procedure using a convex generalized meshfree (GMF) approximation for the large deformation analysis of particle-reinforced rubber compounds on microscopic level. The convex GMF approximation possesses the weak-Kronecker-delta property that guarantees the continuity of displacement across the material interface in the rubber compounds. The convex approximation also ensures the positive mass in the discrete system and is less sensitive to the meshfree nodal support size and integration order effects. In this study, the convex approximation is generated in the GMF method by choosing the positive and monotonic increasing basis function. In order to impose the periodic boundary condition in the unit cell method for the microscopic analysis, a singular kernel is introduced on the periodic boundary nodes in the construction of GMF approximation. The periodic boundary condition is solved by the transformation method in both explicit and implicit analyses. To simulate the interface de-bonding phenomena in the rubber compound, the cohesive interface element method is employed in corporation with meshfree method in this study. Several numerical examples are presented to demonstrate the effectiveness of the proposed numerical procedure in the large deformation analysis.

Asymptotic analysis of Mohr-Coulomb and Drucker-Prager soft thin layers

  • Lebon, F.;Ronel-Idrissi, S.
    • Steel and Composite Structures
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    • v.4 no.2
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    • pp.133-147
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    • 2004
  • This paper deals with the asymptotic analysis of Mohr-Coulomb and Drucker-Prager soft thin layers bonded with elastic solids. In the first part, a mathematical analysis shows how to obtain an interface law that replaces mechanically and geometrically the thin layer. This law is strongly non-linear and couples microscopic and macroscopic scales. In the second part of the paper, the microscopic terms are quantified numerically, and it is shown that they can be neglected.

A design of a low power mobile multimedia system architecture (저전력 모바일 멀티미디어 시스템 구조 설계에 관한 연구)

  • Lee, Eun-Seo;Lee, Jae-Sik;Kim, Byung-Il;Chang, Tae-Gyu
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.231-233
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    • 2005
  • For the low-power design of the mobile multimedia system architecture, this paper modeling the mobile multimedia system and analysis the power consumption profile about the whole communication environment. The mobile system model consist of air interface, RIP front-end, base-band processing module and human interface. For the result of power consumption profile analysis, the power consumption of multimedia processing is above 60% compare to the whole power consumption in mobile multimedia system. To minimize the power consumption in processing module which consumes the large power, this paper proposed the Microscopic DVS technique which applies the optimum voltage for the each multimedia frame. For the simulation result, proposed power minimization technique reduce the power consumption about 30%.

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A SCANNING ELECTRON MICROSCOPIC STUDY OF PREVENTIVE RESIN RESTORATION (우식예방을 위한 레진 충전물의 주사전자현미경적 연구)

  • Kim, Hye-Sook
    • Journal of the korean academy of Pediatric Dentistry
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    • v.11 no.1
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    • pp.57-74
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    • 1984
  • The purpose of this descriptive in vitro study were to evaluate the enamel-resin interface of the preventive resin restoration with regard to etching patterns and resin-tag morphology by means of scanning electron microscope. The results were as follows; 1. Three basic etching patterns were appeared simultaneously in a same microscopic section, in concentration between 20-50% phosphoric acid. 2. In 35% orthorhosphoric acid group etched for 60 second, the etching pattern was most prominent and demonstrate closely interdigitated with enamel-resin interface without the evidence of microspace, and the resin tags were longest ranged from 10-15 um in length. 3. This pattern of interface could reduce the incidence of marginal leakage and 2ndary caries formation. 4, The preventive resin restoration could serve as sealing a questionable occlusal surface.

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Study on the Optical Analysis Equipment Control System for Electronic Parts Inspection (전자 부품 검사용 광학분석 장비 제어시스템에 대한 연구)

  • Lee, Jun Ha
    • Journal of the Semiconductor & Display Technology
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    • v.14 no.4
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    • pp.67-71
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    • 2015
  • Product of technology developed in this study is an external interface for controlling the equipment of pendant key remote control system circuit board, and it is used in the electronic component test equipment system. Main control system module is in the role as a device for controlling the various control devices that make up the integrated system for microscopic examination at the request of the host computer engineers to control the inspection equipment. The pentane-key interface module to its role as a device for controlling the various control devices that make up the integrated system for microscopic examination at the request of the host computer for the engineer to control the inspection equipment. Development of the control system can be expected in the configuration of a system for efficient and accurate inspection of high-precision parts.

Development of a Microscopic Gap Measuring Algorithm with LabVIEW IMAQ Module (LabVIEW의 영상처리 모들을 이용한 미소 거리 측정 알고리즘 개발)

  • Kim, Jae-Hoon;Park, Seung-Kyu;Yoon, Tae-Sung
    • Proceedings of the KIEE Conference
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    • 2008.04a
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    • pp.111-112
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    • 2008
  • In this study, an image processing algorithm with Lab VIEW IMAQ Module is presented and discussed for the development of a microscopic gap measuring system using CCD sensor. LabVIEW IMAQ development application that is developed by National Instrument Co. Inc. has a graphical interface and many image processing functions, so that it provides an easier environment for the development of a measurement algorithm using the image data. Actual microscopic gap measuring experiment was executed using the algorithm developed in this study and it showed a promising result. Also, we could obtain the convenience of Lab VIEW IMAQ in developing the algorithm.

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Experimental study on damage and debonding of the frozen soil-concrete interface under freeze-thaw cycles

  • Liyun Tang;Yang Du;Liujun Yang;Xin Wang;Long Jin;Miaomiao Bai
    • Structural Engineering and Mechanics
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    • v.86 no.5
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    • pp.663-671
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    • 2023
  • Freeze-thaw cycles induce strength loss at the frozen soil-concrete interface and deterioration of bonding, which causes construction engineering problems. To clarify the deterioration characteristics of the interface under the freeze-thaw cycle, a frozen soil-concrete sample was used as the research object, an interface scanning electron microscope test under the freeze-thaw cycle was carried out to identify the micro index information, and an interface shear test was carried out to explore the loss law of interface shear strength under the freeze-thaw cycle. The results showed that the integrity of the interface was destroyed, and the pore number and pore size of the interface increased significantly with the number of freeze-thaw cycles. The connection form gradually deteriorates from surface-to-surface contact to point-to-surface contact and point-to-point contact, and the interfacial shear strength decreases the most at 0-3 freeze-thaw cycles, with small decreases from to 3-8 cycles. After 12 freeze-thaw cycles, the interfacial shear strength tends to be stable, and shear the failure occurs internally in the soil.

Electrical Characteristics on MOS Structure with Irradiation of Radiation (방사선이 조사된 MOS구조에서의 전기적 특성)

  • 임규성;고석웅;정학기
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2001.10a
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    • pp.644-647
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    • 2001
  • The investigations were discussed on the radiation effects of the electrical properties to the p-type MOS capacitors, which were irradiated by cobalt-60 gamma ray sources. The characteristics of capacitance-bias voltage(C-V) and of dielectric dissipation tarter-bias voltage(D-V) on the capacitors were measured at 1 [MHz] frequency. The microscopic behaviors of spate charges in oxide and silicon-silicon dioxide(Si- $SiO_2$) interface were investigated from the experimental data. The C-V characteristics are statical and convenient for the evaluation of the steady state behavior of carriers and interface states characteristics. While, the distribution and magnitude of space charges in oxide can be found out accurately on the $V_{dp}$ in D-V curves. The density of interface states can be deduced with ease from the magnitude of D-peak at depletion state. Thus, it is also concluded that the D-V curves are more useful and easier than conventional C-V curves for analysis of the microscopic and dynamic behavior of carriers in oxide and Si- $SiO_2$interface.

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High-Temperature Tensile Strengths of Alloy 617 Diffusion Weldment (Alloy 617 확산용접재의 고온 인장강도)

  • Sah, Injin;Hwang, Jong-Bae;Kim, Eung-Seon
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.14 no.1
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    • pp.15-23
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    • 2018
  • A compact heat exchanger is one of critical components in a very high temperature gas-cooled reactor (VHTR). Alloy 617 (Ni-Cr-Co-Mo) is considered as one of leading candidates for this application due to its excellent thermal stability and strengths in anticipated operating conditions. On the basis of current ASME code requirements, sixty sheets of this alloy are prepared for diffusion welding, which is the key technology to have a reliable compact heat exchanger. Optical microscopic analysis show that there are no cracks, incomplete bond, and porosity at/near the interface of diffusion weldment, but Cr-rich carbides and Al-rich oxides are identified through high resolution electron microscopic analysis. In high-temperature tensile testing, superior yield strengths of the diffusion weldment compared to the code requirement are obtained up to 1223 K ($950^{\circ}C$). However, both tensile strength and ductility drop rapidly at higher temperature due to the insufficient grain boundary migration across the interface of diffusion weldment. Best fit curves for minimum yield strength and average tensile strength are drawn from the experimental tensile results of this study.

HISTOMORPHOMETRIC AND REMOVAL TORQUE VALUES COMPARISION OF ROUGH SURFACE TITANIUM IMPLANTS (임프란트 표면처리 방법에 따른 골유착의 조직계측학적 분석 및 제거회전력 비교 연구)

  • Lee, Sang-Chul;Song, Woo-Sik
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.23 no.5
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    • pp.396-405
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    • 2001
  • Osseointegrated implants are used for the fixation of dental prosthesis with good long-term clinical results. In an attempt to improve the quantity and quality of the bone-implant interface, numerous implant modification have been used. Implants surface modifications have been used such as titanium-plasma sprayed, hydroxyapatite-coating, sandblasted, sandblasted and acid-etched, acid-etched. Rough surface implants have greater implant surface area and enhance the bone-implant interface and improve stabilization. The purpose of present study was to evaluate light microscopic and scanning microscopic examinations and removal torque value of newly developed calcium phosphate blast and acid-etched implant in the femur of rabbits. Titanium plasma sprayed(TPS) implant served as controls. After 12 weeks of healing of the femurs of 12 rabitts, the implant-containing segments of femur were removed on bloc and bone block including sections. Histologic examination and histomorphometric and removal torque values comparision were made for two implants. Obtained results are follows: 1. Newly developed calcium phosphate blasted and acid-etched implants were in close contact with bone under light microscopic examinations. 2. New implants showed mean bone-to implant contact 59.8%, whereas TPS implants showed mean bone-to implant contact 54.5% (statistically no difference p<0.05). 3. New implants showed mean bone density 56.7%, whereas TPS implants showed mean bone density 49.2% (statistically difference p<0.05). 4. New implants demonstrated mean removal torque values 40.5Ncm, whereas the mean removal torque values of TPS implants ranged 39.3Ncm. No statistical differences(p<0.05) were observed between two groups of implants nor was there any difference between the two implants at the clinical level.

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