• Journal of Advanced Marine Engineering and Technology
• /
• 제24권6호
• /
• pp.155-163
• /
• 2000

A technology of full time four wheel drive(4WD) vehicle has been improved greatly, and the market share of full time 4WD has been extended steadily in recent days. The transfer case is an essential element in the 4WD automobile. In this paper, the details of electronically controlled transfer case is described. In order to achieve easy shifting, the shifting, the developed system automate the conversion of "$4\times2\longleftrightarrow4\times4(H)\longleftrightarrow4\times4(L)$". Furthmore, this system employs an chain drive type instead of gear drive type for drive type and synchromesh type instead of constant-mesh type for gear mesh type. Therefore, the developed transfer case is accomplished light-weight, low noise, and compact.d compact.

• 폴리머
• /
• 제36권3호
• /
• pp.262-267
• /
• 2012

할로겐화알킬($PhCH_2Br$, $PhCH_2Cl$, MeI)과 설폰산에스테르(MeOTf)를 개시제로 사용하여 $100^{\circ}C$, 24시간의 반응조건으로 2-(1,3,3-trimethyl-6-azabicyclo[3,2,1]-oct-6-yl)-4,5-dihydro-1,3-oxazoline(TAO)의 중합을 실시, 개시제에 의한 폴리머구조의 영향을 관찰한 결과, 양쪽 개시제 모두 거의 동일한 연쇄이동에서 나타나는 경향과 비슷한 결과를 얻었다. 그러나 개시제에 의한 폴리머의 구조는 설폰산에스테르계 개시제에서는 거의 100% pendant type 폴리머가 생성되는 반면, 할로겐화알킬계 개시제를 사용한 TAO중합은 pendant type 단위와 main chain type의 단위가 소량 생성됨이 확인되어 이것은 구핵성이 높은 할로겐 음이온에 의한 이중이성화중합이 부분적으로 진행되었음을 확인하였으며, 개시제로 Merrifield수지를 사용한 TAO와의 공중합에서는 다량의 단일중합체가 부생되는 그래프트 공중합체가 생성되었다.

• 대한화학회지
• /
• 제46권5호
• /
• pp.432-449
• /
• 2002

본 논문에서는 산화 환원 효소의 최적 pH를 예측해 보았다. Boltzman 분배를 이용하여 어떤 아미노산의 side chain이 물에서 발견될수 있는 상대적 확률이나 물에 대한 상대적 친화력을 구하였으며 p$K_R$을 이용해 protonated 아미노산의 양과 deprotonated 아미소산의 양을 계산하였다. 효소의 최적 pH는 아미노산의 side chain이 물에서 발견될수 있는 상대적 확률과 protonated 또는 deprotonated된 아미노산 양의 곱인 유효 protonated된 양과 유효 depotonated된 양이 같아지는 pH로 예측하였다. 문헌 값과 비교해 보았을 때 예측치는 상당히 일치하는 경향을 보였으며 이 결과 로 효소 자체의 전도도가 생물학적 기능에 있어 매우 중요한 역할을 하는 것을 알 수있다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
• /
• pp.100-103
• /
• 2000

In the case of immobilizing of glucose oxidase into polypyrrole (PPy) using electrosynthesis, the glucose oxidase (GOx) forms a coordinate bond with the polymers backbone. However, because of intrinsic insulation and net-chain of the enzyme, the charge transfer and mass transport are obstructed during the film growth. Therefore, the film growth is dull. We synthesized the enzyme electrode by electropolymerization added some organic solvent. A formative seeds of film growth is delayed by adding ethanol. The delay is induced by radical transfer between ethanol and pyrrole monomer. The radical transfer shares the contribution of dopant between electrolyte anion and GOx polyanion. This may lead to increase amount of immobilized the enzyme in PPy. For the UV absorption spectra of synthetic solution before synthesis and after, in the case of ethanol added, the optical density was slightly decreased for the GOx peaks. It suggests amount of GOx in the solution was decreased and amount of GOx in the film was increased. We established qualitatively that amount of immobilization can be improved by adding a little ethanol in the synthetic solution. It is due to radical transfer reaction. The radical transfer shares the contribution of dopant between small and fast electrolyte anion and big and slow GOx polyanion.

• 청정기술
• /
• 제22권1호
• /
• pp.45-52
• /
• 2016

This study reports on the modeling and simulation of heat transfer in packaging boxes used for vaccine shipping. Both water and n-tetradecane are used as primary insulation materials inside a multi-slab system. The one-dimensional model, which is a spherical model using a radius equivalent to the rectangular geometry of container, is applied in this study. N-tetradecane with low thermal diffusivity and proper phase transition temperature exhibits higher heat transfer resistance during both heating and cooling processes compared to water. Thus, n-tetradecane is a better candidate as an insulating material for packaging containers for vaccine shipping. Furthermore, the developed method can also become a rapid and economic tool for screening appropriate phase change materials used as insulation materials with suitable properties in logistics applications.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 추계학술대회논문집B
• /
• pp.36-41
• /
• 2001

In order to simulate wake of stator and a gas turbine engine's balde row, acryl cylinder and a linear turbine cascade were used respectively in this study. Experimental of heat transfer distributions was done on the passage endwall and blade suction surface. Temperature distributions on the experimental regions were obtained through image processing system by using the cholesteric type liquid crystal which has chain structure of metyl$(CH_3)$. To represent the degree of heat transfer, dimensionless St number was used. The results show that heat transfer on the blade suction surface was increased due to the wake from the cylinder and was decreased as the distance between cylinder row and blade row increases. Because of groth of passage vortex, heat transfer distributions on the trailing edge area showed triangular shape which was little changed with wake. On the other hand, heat transfer on the passage endwall was decreased due to the wake from cylinder. As the distance between cylinder row and blade row increases, heat transfer was more decreased.

• Bulletin of the Korean Chemical Society
• /
• 제27권8호
• /
• pp.1154-1158
• /
• 2006

Anomalously high ionic mobilities of H+ and $OH^-$ are owing to the transfer of $H^+$ by the Grotthus chain mechanism. Molecular dynamics simulations for the system of 215 water including $OH^-$ ion at 298.15 K using the OSS2 model [J. Chem. Phys. 109, 5547 (1998)] as a dissociable water model with the use of Ewald summation were carried out in order to study the dynamics of $OH^-$ in water. The calculated ionic mobility of $OH^-$ is in good agreement with the experimental result and the Grotthus chain mechanism is fully understood.

• 에너지공학
• /
• 제19권1호
• /
• pp.1-7
• /
• 2010

본 정책총설은 세계적인 에너지 수급의 불안정과 온실가스 감축에 대한 규제에 대응하여 안정적 경제성장과 환경보호를 달성할 수 있는 대안을 제시하고 있다. 이를 위해 에너지 수급전체를 최적화하는 에너지체인(energy chain) 접근방식을 채택하고 있다. 에너지체인에 걸쳐 저탄소 친환경 에너지기술의 개발 및 산업화, 주력산업의 저탄소 친환경화, 에너지 효율성의 제고, 에너지원의 확보, 그리고 이들 정책간 정책군의 형성 등을 제시하고 있다.

• Journal of Radiation Protection and Research
• /
• 제16권2호
• /
• pp.67-74
• /
• 1991

육상 섭취 경로에 따른 내부 피폭선량 계산 모델 KFOOD의 파라메터 불착실성 및 민감도를 몬테칼로법을 사용하여 수치 분석하였다. 쌀을 통한 섭취 경로의 경우 KFOOD 코드에 의한 예측치는 아주 보수적인 값을 나타내었다 모델에서 민감도가 큰 입력변수는 방사능의 침적속도와 식물전이제수였다.

• 고무기술
• /
• 제22권1호
• /
• pp.1-14
• /
• 2021