• Title/Summary/Keyword: transfer factor

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화학산업의 국제 기술이전 결정요인에 관한 연구 (A Study on Determinants of International Technology Transfer in Chemical Industry)

  • 정중규;한상국
    • 벤처창업연구
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    • 제13권6호
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    • pp.191-198
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    • 2018
  • 기술이전은 기술공급사와 기술도입사간의 위험과 이익을 공유함에 따라 다양한 동기를 가지고 기술이전을 결정하게 된다. 기술공급사는 기술도입사가 제공하는 경제적 요인, 위험요인, 정부의 정책 및 제도와 해당 기술이전기업들의 경영전략 등 여러 결정요인을 복합적으로 고려하여 기술이전 결정을 하게 된다. 본 연구에서는 화학산업에서 기술이전에 영향을 미치는 요인을 파악하고 기술이전 의도에 미치는 영향력을 분석하였다. 본 연구결과 기술이전 영향요인은 경제적 혜택 요인, 기술적 요인, 위험요인, 사회문화적 요인으로 나타났다. 기술도입사와 기술공급사의 기술이전 영향요인의 유의미한 차이는 경제적 혜택 요인은 기술공급사보다 기술도입사가 중요하게 고려하는 것으로 나타났으며, 기술적 요인은 기술공급사가 기술도입사보다 중요하게 고려하는 것으로 나타났다. 기술이전 의지는 기술도입사가 기술공급사보다 높게 나타났다.

딤플형 판형 열교환기의 열유동 수치해석 (A Numerical Analysis of Flow and Heat Transfer in the Plate Heat Exchanger with Dimple)

  • 안혁진;이상혁;이명성;허남건
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.121-125
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    • 2008
  • In this study, the characteristics of internal flow and the heat transfer performance of dimpled plate heat exchanger were numerically investigated. For the numerical analysis, conjugate heat transfer method between cold fluid - plate - hot fluid was studied with appropriate boundary conditions. Velocity magnitude, temperature and pressure distribution were obtained from the simulation. Correlations for fanning f-factor and Colburn j-factor were obtained from numerical results and compared to the experimented data.

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균열면에 작용하는 내압과 열전달의 영향을 고려한 노즐부의 응력확대계수 해석 (Stress Intensity Factor Analysis of Nozzle Considering Pressure and Heat Transfer on Crack Face)

  • 정민중;김영진;강기주;범현규;표창률
    • 대한기계학회논문집A
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    • 제24권9호
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    • pp.2252-2258
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    • 2000
  • In order to investigate the effect of nozzle on stress concentration in pressure vessels, three dimensional finite element analyses were performed. The results were compared with those for corresponding two dimensional axisymmetric finite element analyses. A three dimensional finite element model with a surface crack was also designed to evaluate the effect of internal pressure and heat transfer on crack face, and the resulting stress intensity factors from the finite element analyses were compared with those for ASME Sec. XI and Raju-Newman's stress intensity factor solution. As a result, the validity of currently available stress intensity factor solutions for a surface crack was reviewed in the presence of geometrical complexity, heat transfer and internal pressure.

Diazotized Chitin에 고정된 $\beta$-glucosidase의 생물반응기에서의 특성, 물질전달계수 및 효율인자에 관한 연구 (Characteristics, Mass Transfer Coefficient and Effectiveness Factor of $\beta$-glucosidase Immobilized on the Diazotized Chitin in Bioreactors)

  • 김종덕;이경희;서석수
    • 한국식품영양과학회지
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    • 제20권5호
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    • pp.494-502
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    • 1991
  • Diazotized chitin(CHITN) as supports of immobilized enzyme, which was obtained by alkaline hydrolysed chitin with NaN3 and HCI was employed to produce CHITN-Gase with glutaraldehyde as bifunctional reagent. Activities of CHITN-Gase were determined with reaction of p-nitro-pheol-$\beta$-D-glucopyranoside(PNG) in plug flow reactor as a reference of CHITA-Gase. Their optimum temperature, pH, Km and Vmax, mass transfer coefficient (h), effctiveness factor(η)were plotted with variation of flow rate and H/D. Mass transfer coefficient(h) of those enzymes increased because of their flux, as flow rates were increased and controlled by reaction rate. Effectiveness factor(η) of both enzymes were nearly 1.0.

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충전층내에서의 열전달특성에 관한 실험적 연구 (An experimental study on the heat transfer characteristics in packed bed)

  • 신현준;양한주;오수철
    • 오토저널
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    • 제4권3호
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    • pp.40-47
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    • 1982
  • Heat transfer on packed bed is considered to be important for the effective designs of chemical reaction equipment, air conditioning system, and storage type heat exchanger, etc. Currently studies are being carried out quite actively in this field in order to increase the heat transfer efficiency. The effect of heat transfer is closely relater to materials, shapes, porosities and packing states of packed bed as well as mutual dimensional relations between particles and the container. Investigation shows that heat transfer results appear to be influenced by such parameters as fluid velocity through packed bed, mass flow, and thermal properties. It is noted that viscosity is also considered to be an important factor in this problem. In this study, effective thermal conductivities on packed bed, effects of thermal conductivity (Ke) and friction factor (Fk) according to change of porosity(.epsilon.) and Reynolds number(Reh(, and pressure loss of the fluid, are experimentally investigated. Results show that the effective thermal conductivity increases and the friction factor decreased, as against the increase of Reynolds number. But as the increase of porosity increase them both.

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휜-히트파이프로 구성된 채널에서 히트파이프의 엇갈림배열에 따른 유동 및 열전달 특성 (Flow and Heat Transfer Characteristics due to Staggered Arrangement of Heat Pipes in Channels with Heat Pipes and Fins)

  • 김성훈;진윤근;김철주
    • 설비공학논문집
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    • 제14권11호
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    • pp.871-879
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    • 2002
  • The characteristics of flow and heat transfer in the heat exchanger of heat pipes with fins have been studied numerically for cooling enhancement of electronic components of KTX (Korea Train eXpress). Numerical analysis and methodology have been conformed by comparing the experimental results for inlined array of heat pipes. The staggered arrangement of heat pipes has been proposed in order to achieve heat transfer enhancement. As results, the geometry change to the staggered array is conformed to increase the heat transfer of the system accompanied by an increase of pressure drop. The current results of friction factor and Colburn j factor are presented in terms of Reynolds number and staggered distance, and are expected to use for design and manufacture of such a system.

Heat Transfer and Friction Behaviour in a Channel with an Inclined Perforated Baffle

  • Krishna Putra, Ary Bachtiar;Ahn, Soo-Whan
    • International Journal of Air-Conditioning and Refrigeration
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    • 제16권2호
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    • pp.70-76
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    • 2008
  • The effects of the inclined perforated baffles on the distributions of the local heat transfer coefficients and friction factors for air flows in a rectangular channel were determined for Reynolds numbers from 23,000 to 57,000. Four different types of the baffle are used. The inclined baffles have the width of 19.8cm, the square diamond type hole having one side length of 2.55cm, and the inclination angle of $5^{\circ}$, whereas the corresponding channel width-to-height ratio was 4.95. Results show that the heat transfer and friction factor depend significantly on the number of baffle holes and Reynolds number. The friction factor decreases with increasing Reynolds number and the number of holes on the baffle, and the heat transfer performance of baffle type II (3 hole baffle) has the best value.

도시철도역사의 유형별 특성을 고려한 환승시설의 중요도 분석 (Importance Factor Analysis on Transfer Facilities by Considering Characteristics of Urban Railway Station)

  • 김황배;안우영;이상화
    • 대한교통학회지
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    • 제32권5호
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    • pp.487-496
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    • 2014
  • 개별 도시철도역사의 불편성에 대한 연구는 활발히 진행되고는 있으나, 역사의 유형별 특성을 고려한 환승편의시설의 중요도(importance factor)에 대한 연구는 미비한 실정이다. 따라서 본 연구에서는 구조방정식모형(SEM: Structural Equation Model)을 활용하여 도시철도역사의 유형(이용수요 및 승강장형태)에 따른 환승편의시설(이동편의시설, 정보제공시설 및 쾌적성 등)의 인과관계를 통계적으로 검증하고 도시철도역사의 유형별 환승편의시설에 대한 중요도 결정모형을 제시하였다. 도시철도역사의 유형별 중요도 분석결과 대형급 역사이면서 섬식과 상대식이 환승할 경우 정보안내시설, 이동편의시설위치 및 쾌적성의 중요도가 높은 것으로 분석되었고, 중형급 역사이면서 상대식과 상대식이 환승할 경우 정보안내시설, 이동편의시설 및 쾌적성의 중요도가 높은 것으로 분석되었다.

확대모형 열교환기를 이용한 공기측 열전달 성능에 관한 연구 (A Study on Beat Transfer Characteristics in the Air Side of Large-scaled Heat Exchanger)

  • 변주석;이진호;홍만기;전창덕
    • 대한기계학회논문집B
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    • 제29권9호
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    • pp.1032-1041
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    • 2005
  • This study is performed to investigate the heat transfer characteristics of heat exchanger according to the arrangement of fins as well as fin configuration by using the four times enlarged model. Friction factor, Colburn j factor and goodness factors are compared to each other to estimate performance of each case for 4 different kinds of fins, which are plain, single side slit, double side slit and louver fin. Results show that heat transfer would be altered by fin arrangement and that friction loss is more affected by fin configurations than by the fin arrangements. In particular, heat transfer depends more on the shape of front row than that of rear row. The heat transfer rate of combined fin arrangement increases a lot more under the same pressure drop than that of conventional fin arrangement. This indicates that the heat exchanger of higher efficiency would be designed by the proper combination of fins, of different shapes.