• 제목/요약/키워드: critical size

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Critical Success Factors for Malaysian SMEs and Large Companies in Commercializing Universities' R&D Outputs

  • Tam, Kok Chian;Chong, Aik Lee;Yee, Angelina Seow Voon;Tham, Joel Kah Marn
    • Asian Journal of Innovation and Policy
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    • 제8권3호
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    • pp.362-377
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    • 2019
  • Commercializing universities' R&D outputs is a major management challenge and there are limited studies to describe this phenomenon from the perspective of companies' management. Experiences of six small and medium size and four large companies' management's respondents are gathered through semi-structured face-toface interviews. Twelve critical success factors revealed by the respondents, namely R&D product and market readiness, good partnership with university, researcher's motivationand commitment, availability of resources, government support and motivation, control and ownership of intellectual property rights, university's management support, entrepreneurial culture in the university, an open communication and trusting relationship, researchers' skills, a risk taking attitude, and existence of performance measures as important to commercialize the universities' R&D outputs in Malaysia. The different views from the management of small and medium size, and large companies are also discussed in this study.

Twisting된 BSCCO 선재 제조 및 미세조직 연구 (A Study of fabrication and microstructural evolution of twisted BSCCO superconductor tape)

  • 임준형;지봉기;박형상;주진호;장미혜;고태국;이상진;하홍수;오상수
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2000년도 KIASC Conference 2000 / 2000년도 학술대회 논문집
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    • pp.112-114
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    • 2000
  • We fabricated BSCCO multifilaments superconductor tape and evaluated the effect of twisting on the microstructural evolution and critical current. Twist pitches of the tapes are in the range of 70 - 8 mm and uniformly deformed. It was observed that grain size and the degree of texture decreased as decreasing pith, probably due to the formation of the irregular interface between Ag and filaments. In addition, critical current of the tapes decreased to 6.5A with decreasing pitch to 8 mm, showing 48% of degradation compared to the untwisted tape(12.5 A). These reduction of critical current may be related to the interface irregularity, smaller grain size, worse texture and the presence of cracks due to the induced strain during twisting processing.

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Modeling Of Critical Flux Conditions In Crossflow Microfiltration

  • Kim, Su-han;Park, Hee-kyung
    • Water Engineering Research
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    • 제1권2호
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    • pp.119-127
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    • 2000
  • In the process of crossflow microfiltration, a deposit of cake layer tends to form on the membrane, which usually controls the performance of filtration. It is found, however, that there exist a condition under which no deposit of cake layer is made. This condition is called the sub-critical flux condition, and the critical flux here means a flux below which a decline of flux with time due to the deposit of cake layer does not occur. In order to study the characteristics of the critical flux, a numerical model is developed to predict the critical flux condition, and is verified with experimental results. For development of the model, the concept of effective particle diameter is introduced to find a representative size of various particles in relation to diffusive properties of particles. The model is found to be in good match with the experimental results. The findings from the use of the model include that the critical flux condition is determined by the effective particle diameter and the ratio of initial permeate flux to crossflow velocity.

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미세립강 잠호 용접부의 COD에 미치는 시편 크기의 영향 (Efforts of Specimen Sizes on Crack Opening Displacement (COD) for Submerged Arc Weldments of Fine Grained Steel)

  • 윤중근;김대훈;김문일
    • Journal of Welding and Joining
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    • 제1권2호
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    • pp.53-60
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    • 1983
  • COD test based on fracture mechanics concept was used in this study to evaluate the fracture toughness quantitatively. Effects of specimen sizes on critical COD value for ABS EH 36 steel and its submerged arc weldments, and the variation of critical COD value depending on metallurgical/mechanical heterogeneities caused by weld thermal cycles were investigated. Experiment was performed by using specimens made from base metal and submerged arc weldments according to BS 5762. Obtained results are summarized as follows; 1) Critical COD value for base metal decreases with increasing thickness of specimen. On hand, as the reduction ratio of critical COD decreases with increasing specimen thickness, critical COD value becomes constant above a thickness of specimen. 2) Critical COD value for weldment decreases with increasing thickness of specimen and was also affected by metallurgical states of base metal. 3) Size effects for weldment was greater at the hardened region. 4) Critical COD value was affected by microstructural change due to weld thermal cycles in weldments; that is, accicular ferrite formation is favorable for increasing of COD value.

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만곡하천의 자갈하상재료 분포에 따른 한계수류력 평가 (Estimating Critical Stream Power by the Distribution of Gravel-bed Materials in the Meandering River)

  • 신승숙;박상덕;이승규;지민규
    • 한국수자원학회논문집
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    • 제45권2호
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    • pp.151-163
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    • 2012
  • 산지하천의 자갈하상재료 분포는 최근 특정규모 홍수의 수류력에 의한 유사 이송 및 퇴적 과정에 의해 형성되며, 장갑화된 하천에서 한계수류력을 평가하는 것은 안정하도설계를 위해 중요하다. 자갈하상 하천 종단지점과 만곡부 일정구간의 세부지점에대한하상재료의입도분포를조사하고, 한계유속 및 한계수류력을 평가하였다. 자갈하상 재료에 대한 Yang의 한계단위수류력과 Bagnold의 한계수류력은 상류로 갈수록 급격히 증가했다. 계획홍수량에 근거한 무차원 전단응력은 Shields 도표에서대부분조사지점의자갈하상재료가소류사형태로이동하는것으로평가되었다. 만곡부에 대한 평균입경은 상류 유입수의 1차 수충지점에서 가장 컸으며, 반사흐름에 의한 2차 수충지점에서 두 번째로 큰 입경을 보였다. 수충직하류지점들에서상대적으로작은평균입경을보였다. 만곡부의 평균한계유속 범위는0.77~2.60m/s의 범위이며, 한계단위수류력은 경사가 급한 1차 수충부에서는 상당히 컸다. 한계수류력의 분포는 7~171W/m2의 범위로 하천 횡단보다는 종단에 따른 변화가 뚜렷했고, 만곡 외측 1차 수충지점과 반사흐름 2차 수충지점에서 크게 작용하는 것으로 평가되었다.

Comparative Evaluation of Fibrin for Bone Regeneration in Critical Size Calvarial Defects

  • Song, Gin-Ah;Kim, Soung Min;Woo, Kyung Mi
    • International Journal of Oral Biology
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    • 제39권3호
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    • pp.153-157
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    • 2014
  • Natural biopolymers such as collagen and fibrin have been widely used in bone regenerative applications. Despite the frequent use, their comparative biological propertiesis are largely unknown. In a previous study, we found the superiority of fibrin to collagen in the adsorption of serum proteins and the proliferation and differentiation of cultured osteoblasts. In this study, we used an in vivo model to evaluate how effectively fibrin supports bone regeneration, as compared with collagen. Collagen and fibrin were placed in critical size defects made on rat calvarial bones. Compared with collagen, fibrin supported substantially more new bone tissue formation, which was confirmed by micro-CT measurement and histological analyses. The cells in the regenerative tissues of the fibrin-filled defects were immunostained strongly for Runx2, while collagen-placed defects were stained weakly. These in vivo results demonstrate that fibrin is superior to collagen in supporting bone regeneration.

구조물용 강재의 파단기준에 대한 실험 및 이론 연구 (Experimental and Theoretical Investigations on the Fracture Criteria for Structural Steels)

  • 정준모;조상래
    • 대한조선학회논문집
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    • 제45권2호
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    • pp.157-167
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    • 2008
  • Six smooth flat tensile specimens and eighteen punch specimens with three different thicknesses were machined from steel of JIS G3131 SPHC. In addition to punch tests, incremental tensile tests were conducted to obtain average true flow stress - logarithmic true strain curves. Through parametric FE simulations for the tensile specimens, material parameters related to GTN model were identified. Using indenters with three kinds of radius, punch tests were carried out to obtain fracture characteristics of punch specimens. Numerical analyses using both fracture models, GTN and $J_2$ plasticity model, gave that the former estimated well the fracture of punch specimen but the latter did not. A new concept for critical size of plate elements was introduced based on minimum relative sharpness between contact structures. Consequently, a new criterion for critical element size was proposed to be less than 20% of minimum relative radius of interacting structures.

Pool-Boiling Critical Heat Flux of Water on Small Plates: Effects of Surface Orientation and Size

  • Yang, Soo-Hyung;Baek, Won-Pil;Chang, Soon-Heung
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1996년도 춘계학술발표회논문집(2)
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    • pp.337-342
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    • 1996
  • The pool-boiling critical heat flux (CHF) of water on small flat plates has been experimentally investigated focusing on the effects of the inclination angle and size of the heated surface under near atmospheric pressure. The second-phase experiment was accomplished to find out the general CHF behavior for over-all inclination angles from -90$^{\circ}$ to 90$^{\circ}$using two plate-type test sections (30$\times$150 mm and 40$\times$150 mm) submerged in a slightly subcooled water pool. Test results generally confirm the first-phase findings and show little effect of inclination angle for inclined upward-facing cases. CHF position moves to lower position with the increase of the heater characteristic size and inclination angle(from -30$^{\circ}$to 60$^{\circ}$).

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In-situ 공정에 의한 복합솔더 제조 (Manufacturing of Composite Solders by an In-situ Process)

  • 황성용;이주원;이진형
    • 한국주조공학회지
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    • 제22권1호
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    • pp.35-41
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    • 2002
  • To improve the reliability of solder joints, a composite solder which consists of solder matrix and intermetallic reinforcements was manufactured by a new method. The cast ingot of Sn-6.9Cu-2.9Ag alloy had primary Cu6Sn5 intermetallics in the form of dendrites. After rolling the ingot, the intermetallic dendrites were crushed into fine particles and distributed uniformly throughout the solder matrix. As the rolled strips became thinner, the average size of the crushed particles reached a critical size which did not decrease any more by further rolling. The critical size was nearly the same as the average width of intermetallic dendrite trunk. The crushed intermetallic particles did not melt and remained in solid state during reflow soldering due to their high meltingterm-perature. The coarsening and gravitational segregation of the particles were observed during reflow soldering.