• Journal of Mechanical Science and Technology
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• 제17권7호
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• pp.1104-1110
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• 2003

The present study investigates the hemorheological characteristics of blood flow with applying vibration to a non-aggregating red blood cell suspension. In order to obtain the non-aggregating RBC suspension, blood samples were treated with vibration at a specified condition, which viscosities were taken before and after the treatment, respectively. The viscosity of the blood samples after treatment was higher than before treatment. These treated blood samples were forced to flow through a capillary tube that was vibrated perpendicularly to the direction of the flow. The experimental results showed that vibration caused a reduction of the flow resistance of the non-aggregated blood. The reduction of the flow resistance was strongly dependent on both frequency and amplitude of vibration. These results show potential in treating various diseases in the microcirculation associated with blood cell aggregation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.643-646
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• 2002

Experimental study was conducted to reveal the flow mechanism under rotating stall in an axial flow fan. For this study unsteady pressure was measured using high frequency pressure transducers mounted on the casing wall of rotor passage and total pressure fields were measured at the rotor upstream and downstream. The measured pressure signal was analyzed by Wavelet Transform and Double Phase Locked Averaging Technique. From the result of unsteady pressure field of the casing wall, one period of rotating stall was divided into three zones and the flow characteristics on each zone were described in detail. The pressure field was also analyzed in terms of the pressure distribution along pressure side and suction side of blade tip. From the result of total pressure fields at inlet and outlet of the rotor, the useful information on the characteristics of the stall cell in radial direction was provided.

• Journal of Mechanical Science and Technology
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• 제15권12호
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• pp.1892-1899
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• 2001

An experimental study was performed for measuring velocity and turbulence intensity in a circular tube for Re= 10,000, 15,000 and 20,000, with swirl and without swirling flow. The velocity fields were measured using PIV techniques and swirl motion was produced by a tangential inlet condition. Some preliminary measurements indicated that over the first 4 diameter, two regions of flow reversal were set up (the so called 2-cell structure). At the highest Reynolds numbers, the maximum values of the measured axial velocity components had moved toward the test tube wall and produce more flow reversal at the conter of the tube. As the Reynolds number increased, the turbulence intensity of swilling flow at the tube inlet also increased.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.78-85
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• 2011

The Vortex-In-Cell(VIC) method combined with panel method is applied to the analysis of incompressible unsteady viscous flow. The dynamics of resulting flow is governed by the vorticity transport equation in Lagrangian form with vortex particle representation of the flow field. A regular grid which is independent to the shape of a body is used for numerical evaluation based on immersed boundary technique. With an introduction of this approach, the development and validation of the VIC method is presented with some computational results for incompressible viscous flow around two or three dimensional bodies such as wing section, sphere, finite wing and marine propeller.

• 디지털융복합연구
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• 제18권8호
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• pp.55-67
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• 2020

본 연구는 CELL교육과정 참여가 대학생의 학습몰입, 학습동기, 학업적자기효능감, 자기주도학습능력에 미치는 효과를 알아보고자 하였다. 이를 위해 2020년 1학기에 K대학교 재학생 386명을 대상으로 사전·사후 설문조사를 실시하고 SPSS를 사용하여 분석하였다. 주요 연구결과는 다음과 같다. 첫째, CELL교육과정 참여가 대학생의 학습몰입, 학습 동기, 학업적자기효능감, 자기주도적학습능력에 통계적으로 유의한 향상을 보였다. 둘째, 성별에 따른 분석에서는 여학생의 경우에만 학습몰입, 학업적자기효능감, 자기주도학습능력에 유의한 향상을 보였다. 셋째, 학년별 분석에서는 2학년은 학습몰입과 자기주도학습능력에, 3학년은 모든 변인에, 4학년은 학업적자기효능감과 자기주도학습능력에 유의한 향상을 보였다. 넷째, 참여학생 인터뷰를 통해 참여소감과 개선점을 정리하였다. 본 연구는 CELL교육과정의 효과를 살펴보고 체계적인 운영과 지원을 위한 실천적인 방안을 제시하였다는 점에서 의의를 지닌다.

• 식물조직배양학회지
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• 제25권2호
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• pp.81-88
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• 1998

Southeast Asian javanica 벼 품종 Tinawen의 진탕 배양세포로부터 나출된 원형질체의 효과적인 배양과 식물체 재분화가 조사되었다. Lolium multiforum과 Oryza ridleyi의 진탕 배양세포들을 feeder cell로 사용했고 여러가지 재분화 배지를 이용하여 원형질체로부터 유도된 colony들을 재분화 시켰으며, 또한 식물체 재분화율을 높히기 위해 원형질체로 부터 유도된 colony들을 dehydration 시켜 재분화율을 조사하였다. L multiflorum 또는 O. ridleyi의 진탕 배양세포들을 feeder cell로 사용했을 때 원형질체의 평판효율은 feeder cell type과 age에 따라 차이가 났지만 0.09%에서 1.48% 범위로 나타났고, L. multiflorum을 feeder cell로 사용했을 때가 O. ridleyi cell을 사용했을때 보다 6배 높게 원형질체 평판효율을 얻었다. Feeder cell로 L. multiflorum을 사용하여 배양된 원형질채로부터 유도된 colony들을 dehydration 시킨 경우는 19.3-31.7%, O. ridleyi을 사용한 경우는 13.0-18.0%, 또한 이들 두 진탕 배양세포들을 혼합한 것을 사용한 경우는 18.0-22.0%의 식물체 재분화율을 얻은 반면에, dehydration을 시키지 않았을 때는 각각 2.0-7.0%, 3.0-5.0%, 0-4.0%의 재분화율을 얻었다. 원형 질체에서 재분화된 식물체의 flow cytometry를 이용한 배수성 분석 결과 대부분의 식물체가 이배체로 나타난 반면, 단지 34개중 두 식물체에서만이 4배체로 나타났다. 재분화된 식물체들은 온실에 옮겨 기른 결과 정상적인 임성을 나타내었다.

• 한국양식학회지
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• 제11권1호
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• pp.77-81
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• 1998

잉어(Cyprinus carpio) 암컷과 붕어(Carassius auratus) 수컷간 유도된 잡종에 대한 세포 유전학적 연구를 수행하였다. 유도된 잡종의 세포 및 핵의 크기는 양친의 중간값을 나타내었고, 염색체의 경우 잉어, 붕어 및 유도된 잡종 모두 2n=100 으로 나타났다. Flow cytometry를 이용, 잡종의 genome size를 분석한 결과, 유도된 잡종은 3.7pg/cell를 갖음으로서 잉어(3.6pg/cell)와 붕어(3.8pg/cell)의 중간치를 나타내었다.

• Journal of Advanced Marine Engineering and Technology
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• 제30권2호
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• pp.225-230
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• 2006

This study investigates drying condition when a small fan is added to a operating the free-breathing proton exchange membrane fuel cells (PEMFCs) with dry $H_2$ and Air. Polarization tests were conducted on PEMFCs at cell temperatures between 30 and $50^{\circ}C$ under dry operation. In the results, the cell performance strongly depended on the cell temperature and the cathode gas stoichiometric flow rates. The cell performance increases as cell temperature decreases from 50 to $30^{\circ}C$. In the domain where the stoichiometry of air is quite large, reduction of the concentration overpotential compensated the increased internal resistance due to drying. The maximum performance was obtained at the small air flow rate beyond which flooding occurs. This indicates that the fan should be operated in the stoichiometry domain with a well designed cell structure to avoid flooding.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.112-119
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• 2005

Efficient plant regenerationsystem from cell suspension cultures was established in D. acicularis (2n = 90) by monitoring ploidy level and visual selection of the cultures. The highly regenerable cell lines selected maintained original ploidy level and consisted of compact cell clumps with yellowish color and relatively moderate growth, suggesting that it is possible to select visually the highly regenerable cell lines with the original ploidy level. All the regenerated plantlets from the highly regenerable cell cultures exhibited normal phenotypes and no variations in ploidy level were observed by flow cytometry (FCM) analysis.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2385-2389
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• 2008

This is the experimental research that tries to explain a variety of RH is how to affect the cell performance and the flooding phenomenon of proton exchange membrane fuel cell (PEMFC). A value of PH changes to 0%, 50% and 90% as its variation, either stoichiometric flow rate changes to 1.5, 2 and 4. Into the comparison between theoretical and experimental value, this study analyzes that a variety of PH is how 10 affect flooding in the cathode of the proton exchange membrane fuel cell. The effect of air stoichiometry, air humidity and different flow fields are also discussed in this paper This study has accomplished the measurement of performance as the variety of RH in the cathode of proton exchange membrane fuel cell, moreover it has recorded the visualization of flooding in the cathode with a high-speed micro camera.