• 제목/요약/키워드: Cell plasticity

검색결과 165건 처리시간 0.02초

P/M법과 유도가열법을 이용한 A1 Foam 재료의 기공제어 (Control of Cell Morphology of Al Foams fabricated by P/M Method and Induction Heating)

  • 윤성원;이승후;강충길
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 추계학술대회 논문집
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    • pp.289-292
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    • 2001
  • Aluminium foams, having a closed cell structure, fabricated by applying the powder compact method and an induction heating were studied. The powdered A6061 mixed with the powdered titanium hydride as a foaming agent was hot pressed into a foamable precursor. The resulting precursor was foamed by induction heating up to desired temperature. The effects of the titanium hydride content ($0.3{\~}1.5 wt.\%$), pressing pressure of the foamable precursor material (50-150kN), the forming temperature ($610{\~}690^{\circ}C$) and heating rate during foaming on the expansion behavior of the foam were investigated.

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용융탄산염 연료전지용 금속분리판 굽힘 공정의 유한요소 해석을 통한 스프링백 분석 (FEM Analysis of spring back in bending process of center plate for molten carbonate fuel cell)

  • 이창환;류승민;양동열;김영진;강동우;장인갑;이태원
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2009년도 춘계학술대회 논문집
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    • pp.220-223
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    • 2009
  • Metallic bipolar plate for molten carbonate fuel cell(MCFC) is composed of the shielded slot plate and the center plate. Among these, the center plate plays an important role in gas sealing. Therefore, manufacturing of the center plate is considered one of the key issues in MCFC. The center plate is manufactured by bending process. In bending process, springback and recoiling are two main problems. By using the modified punch shape with 'step', springback and recoil are reduced. The aim of this article is to find the effect of modified punch shape. So, the bending stress along thickness direction and material direction were investigated using FEM.

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Polyadenylation-Dependent Translational Control of New Protein Synthesis at Activated Synapse

  • Shin Chan-Young;Yang Sung-Il;Kim Kyun-Hwan;Ko Kwang-Ho
    • Biomolecules & Therapeutics
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    • 제14권2호
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    • pp.75-82
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    • 2006
  • Synaptic plasticity, which is a long lasting change in synaptic efficacy, underlies many neural processes like learning and memory. It has long been acknowledged that new protein synthesis is essential for both the expression of synaptic plasticity and memory formation and storage. Most of the research interests in this field have focused on the events regulating transcriptional activation of gene expression from the cell body and nucleus. Considering extremely differentiated structural feature of a neuron in CNS, a neuron should meet a formidable task to overcome spatial and temporal restraints to deliver newly synthesized proteins to specific activated synapses among thousands of others, which are sometimes several millimeters away from the cell body. Recent advances in synaptic neurobiology has found that almost all the machinery required for the new protein translation are localized inside or at least in the vicinity of postsynaptic compartments. These findings led to the hypothesis that dormant mRNAs are translationally activated locally at the activated synapse, which may enable rapid and delicate control of new protein synthesis at activated synapses. In this review, we will describe the mechanism of local translational control at activated synapses focusing on the role of cytoplasmic polyadenylation of dormant mRNAs.

연료전지 분리판의 고온 강성 인자 연구 (Assessment of the Stiffness factor of the Separator Plate at the Elevated Temperature)

  • 김정현;우동욱;이상욱
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2007년도 추계학술대회 논문집
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    • pp.296-299
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    • 2007
  • The focus of this study is to estimate the stiffness factor of the separator plate of MCFC (Molten Carbonate Fuel Cell) at the elevated temperature. The process factors affecting the stiffness of the separator plate were chosen to determine the most important factor using the finite element analysis with the Taguchi method. The most influential factor, picked out by the ANOYA, turned out the pitch in the separator plate.

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유한요소해석을 이용한 EGL 도금조 Polisher Brush의 마모예측 (Wear for Polisher Brush of EGL Plating Cell using Finite Element Analysis)

  • 구자경;노학곤;허성찬;송우진;구태완;김정;강범수
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2009년도 추계학술대회 논문집
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    • pp.342-345
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    • 2009
  • Electro galvanized steel is electroplated cold roller steel for improving corrosion resistance and paintability, and is widely used in automobiles and home appliances. In the electroplating line for manufacturing electro galvanized steel if plating process is carried out with impurity on conductor roll surface, the defects in manufacturing process occurs because of steel fault. For quality, polishing is always required to separate impurity on surface of conductor roll. In this study, finite element analysis of wear for polisher brush is carried out for replaced time of it.

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마이크로 코일 스프링의 스프링 상수 평가 (Evaluation of the Spring Constant of a Micro Coil Spring)

  • 이종길;전병희
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 추계학술대회 논문집
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    • pp.255-259
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    • 2001
  • The spring constant of a micro coil spring was measured by uniaxial tensile test. The inner diameter of it is $35{\mu}m$ and the pitch size is about $23{\mu}m$. A suing constant measurement system was developed. It consists of control units, load cell units, linear stages and several specially designed jigs and fixtures. Load and displacement are measured using a commercial load cell of 1000g capacity and a magnetic scale of $0.5{\mu}m$ resolution. In this study, a method to measure the spring constant of micro coil spring is presented and the relationship between misalignment of specimen and measurement error is discussed.

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Multi-scale model for coupled piezoelectric-inelastic behavior

  • Moreno-Navarro, Pablo;Ibrahimbegovic, Adnan;Damjanovic, Dragan
    • Coupled systems mechanics
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    • 제10권6호
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    • pp.521-544
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    • 2021
  • In this work, we present the development of a 3D lattice-type model at microscale based upon the Voronoi-cell representation of material microstructure. This model can capture the coupling between mechanic and electric fields with non-linear constitutive behavior for both. More precisely, for electric part we consider the ferroelectric constitutive behavior with the possibility of domain switching polarization, which can be handled in the same fashion as deformation theory of plasticity. For mechanics part, we introduce the constitutive model of plasticity with the Armstrong-Frederick kinematic hardening. This model is used to simulate a complete coupling of the chosen electric and mechanics behavior with a multiscale approach implemented within the same computational architecture.