• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.103-108
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• 2003

The effect of equivalence ratio and fuel/air mixing quality on the phase-resolved gas temperatures at different phases of the oscillating pressure cycle was experimentally investigated. An atmospheric pressure, optically accessible and laboratory-scale dump combustor operating on methane with heat release rate of 1.59kW was used. Temperature measurements were made using coherent anti-Stokes Raman spectroscopy (CARS) at several spatial locations for typical unstable combustion conditions. Analysis was conducted using parameters such as phase-resolved averaged temperature, normalized standard deviation and temperature probability distribution functions (PDFs). Also the probability on the occurrence of high temperature (over 1900K) was investigated to get the information on the perturbation of equivalence ratio and NOx emission characteristics. It was shown that most of temperature histograms exhibit Gaussian profile which has short breadth of temperature fluctuation at equivalence ratio of 0.6, while beta profile was predominant for the cases of other equivalence ratios (${\Phi}$=0.55, 0.50). The characteristics on the occurrence of high temperature also displayed periodic wave form which is very similar to the pressure signal. And the amplitude of this profile goes larger as the fuel/air mixing quality become poorer. These also provided additional information on the perturbation of equivalence ratio at flame as well as NOx emission characteristics.

• 한국작물학회지
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• 제60권1호
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• pp.97-106
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• 2015

Platycodon grandiflorum, commonly known as Doraji in Korea, has a wide range of pharmacologic properties, such as reducing adiposity and hyperlipidemia, and antiatherosclerotic effects. However, the mechanisms underlying these effects remain unclear. In order to profile proteins from the nodal segment, callus, root and shoot, high throughput proteome approach was executed in the present study. Two dimensional gels stained with CBB, a total of 84 differential expressed proteins were confirmed out of 839 protein spots using image analysis by Progenesis SameSpot software. Out of total differential expressed spots, 58 differential expressed protein spots (${\geq}$ 2-fold) were analyzed using MASCOT search engine according to the similarity of sequences with previously characterized proteins along with the UniProt database. Out of 58 differential expressed protein, 32 protein spots were up-regulated such as ribulose-1,5-bisphosphate carboxylase, endoplasmic oxidoreductin-1, heat stress transcription factor A3, RNA pseudourine synthase 4, cysteine proteinase, GntR family transcriptional regulator, E3 xyloglucan 6-xylosyltransferase, while 26 differential protein spots were down-regulated such as L-ascorbate oxidase precursor, late embryogenesis abundant protein D-34, putative SCO1 protein, oxygen-evolving enhancer protein 3. However, frequency distribution of identified proteins using iProClass databases, and assignment by function based on gene ontology revealed that the identified proteins from the explants were mainly associated with the nucleic acid binding (17%), transferase activity (14%) and ion binding (12%). In that way, the exclusive protein profile may provide insight clues for better understanding the characteristics of proteins and metabolic activity in various explants of the economically important medicinal plant Platycodon grandiflorum.

• 한국의류학회지
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• 제32권7호
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• pp.1129-1136
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• 2008

The gaiter is one of the personal protective equipments worn in various industrial sites. This study was performed on humans to investigate the physiological strain of wearing gaiters and to compare control gaiters that are currently on the market and new gaiters that are developed for alleviating heat stress. Experiments were conducted in a climatic chamber of WBGT $30.0\pm0.7^{\circ}C$ under five differed experimental conditions: None, Control A, Control B, New A, New B. The results were as follows. The temperature inside gaiters was significantly lower in both New A and New B than in both Control A and Control B and the difference between news and controls was 1$^{\circ}C$ (p<.01). The humidity inside gaiters in both New A and New B were higher than that in Control A, and lower than that in Control B (p<.01). The outermost surface temperature of the gaiter was the lowest in None and it increased in the following order: New B < New A < Control A < Control B. Mean skin temperature was higher by 0.14$^{\circ}C$ in wearing gaiters than in no gaiters. Skin temperatures in lower body were lower in Control than in New and skin temperature in upper body were higher in Control than in New (p<.01). Local sweat rate, total weight loss and subjective sensations did not show a significant difference according to the gaiters. It was concluded that wearing gaiters affected distribution of skin temperature and local sweat rate.

• 한국항공우주학회지
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• 제30권5호
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• pp.9-14
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• 2002

열-기계-전기 하중이 완전 연계된 스마트 구조물의 응력과 변형을 정확히 예측할 수 있는 판 이론을 개발하였다. 두께 방향으로 변위와 온도장은 3차 곡선에 선형 지그재그 장을 중첩하여 구하였다. 횡 수직방향 변형을 고러하기 위해 횡 수직 변위를 두께방향으로, 포물선으로 가정하였다. 전기장은 선형지그재그 형태로 가정하였다. 스마트 구조물의 층에 의존하는 변위장과 온도장의 자유도를 층 사이의 연속조건과, 평판의 위 아래 횡 방향 전단응력이 존재하지 않는다는 조건으로부터, 기준면에 의한 자유도로 나타내었다. 수치 예를 통해 제안된 이론의 정확도와 효율성을 평가하였다. 본 연구에서 제시한 고차 지그재그 이론은 열 환경 하에서 두꺼운 지능 복합재료 평판의 정적, 동적 거동 해석에 사용될 수 있다.

• Progress in Superconductivity
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• 제10권1호
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• pp.60-67
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• 2008

We present domestic efforts for superconducting fault current limiter (SFCL) application in the Korea Electric Power Corporation (KEPCO) grid and pending points at issue. KEPCO's decision to upgrade the 154 kV/22.9 kV main transformer from 60 MVA to 100 MVA cast a problem of high fault current in the 22.9 kV distribution lines. The grid planners supported adopting an SFCL to control the fault current. This environment friendly to SFCL application must be highly dependent upon the successful development of SFCL having specifications that domestic utility required. The required conditions are (1) small size of not greater than twice of 22.9 kV gas insulated switch-gear (GIS), (2) sustainability of current limitation without the line breaking by circuit breakers (CB) for maximum 1.5 seconds. Also, optionally, recommended is (3) the reclosing capability. Conventional resistive SFCLs do not meet (1) $\sim$ (3) all together. A hybrid SFCL is an excellent solution to meet the conditions. The hybrid SFCL consists of HTS SFCL components for fault detection and line commutation, a fast switch (FS) to break the primary path, and a limiter. This characteristic structure not only enables excellent current limiting performances and the reclosing capability, but also allows drastic reduction of HTS volume and small size of the cryostat, resulting in economic feasibility and compactness of the equipment. External current limiter also enables long term limitation since it is far less sensitive to heat generation than HTS. Semi-active operation is another advantage of the hybrid structure. We will discuss more pending points at issues such as maintenance-free long term operation, small size to accommodate the in-house substation, passive and active control, back-up plans, diagnosis, and so on.

• 대한기계학회논문집B
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• 제34권8호
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• pp.749-754
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• 2010

비강의 3 가지 생리학적 주요기능은 공기조절, filtering, 후각기능이다. 비강 내 공기유동특성에 대한 지식은 비강 호흡의 생,병리학적 측면을 기반으로 한다. 본 연구실에서는 정상 및 변형된 비강 모델 내 유동에 관하여 일정유량 및 주기유동 하에서 다양한 PIV 실험들을 진행해 왔다. 비대칭 비강을 가진 환자들 중에 일부는 고통을 느끼거나 불편함을 호소하는 반면 그렇지 않은 환자들도 있다. 이 원인을 밝히기 위하여 비중격이 휘어진 비대칭 모델에 대하여 PIV 및 수치해석적인 연구를 진행하였다. 이를 위하여 이비인후과 의사로부터 모델에 관한 CT 데이터를 제공받아 PIV 및 수치해석을 통해 호기 및 흡기시의 RMS 값 및 속도 분포를 얻었다. 모델에 따라 좌우 유량이 크게 다른 것을 확인할 수 있었고 이것이 고통을 느끼는 원인중에 하나가 될 수 있다.

• 대한수의학회지
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• 제14권1호
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• pp.77-90
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• 1974

Hemolytic reaction of normal fresh chicken serum on sheep erythrocytes was studied and the following experimental results were obtained and summarized. 1. Chicken sera, 258 (78%) out of 344 samples showed hemolytic activity on sheep erythrocytes. 2. Distribution of a different hemolytic titer of chicken sera was not dependent to sex and age difference of test chicken. 3. Hemolytic activity of serum component obtained from normal fresh chicken was heat inactivated at $56^{\circ}C$. 30 minutes heating. 4. The most enhanced hemolytic activity of chicken serum on sheep erythrocytes was observed at the incubation temperature of $46^{\circ}C$. 5. The most effective pH for the hemolytic reaction of chicken serum on sheep erythrocytes was observed at 7.0, and pH 6.0 or 8.5 resulted less or no hemolysis. 6. Hemolytic reaction of chicken serum and sheep erythrocytes required Mg⧻ and Ca⧻ ions as, co-factor, and the former was required more compared to the latter. 7. Hemolytic activity of chicken serum was observed in ChC 2, 4 fraction but not in ChC 1, 3, ChC 3, 4, ChC 1, 2, 4 and ChC 1, 2, 3 fractions. 8. In electron micrography, morphological changes of sheep erythrocyte membrane by normal chicken serum was similar to that of immune hemolysis: that was, the hemolytic hole was circular and it was surrounded with a white ring. 9. Electron micrography of morphological changes on sheep erythrocyte membrane indicated that the size of hemolytic hole and white ring were functional to the chicken serum concentration used and reaction time.

• 한국화재소방학회논문지
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• 제22권1호
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• pp.128-138
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• 2008

소규모 점포가 밀집한 재래시장에 적재된 물품은 고무, 합성섬유제품, 플라스틱 등으로 대부분이 화재발생시 높은 열량을 방출하여 인접 가연물에 쉽게 착화되는 경향이 있다. 또한 점포간에 방화구획이 마련되지 않고 커튼과 같은 가연성물질로 구획되어 화재가 대형화될 수 있는 실정이다. 따라서 낙후된 재래시장의 화재위험성, 취약요인을 분석하고 화재발생시 가장위험하다고 판단되는 점포칸막이의 유무 가연물의 적재 높이 등을 화재 시 위험요소로 설정하여 Field 모델링이 가능한 화재시뮬레이션을 활용하여 스프링클러설비의 소화성능변화와 화재특성을 분석하였다. 그 결과 점포칸막이, 가연물의 적재높이 등은 스프링클러 살수반경에 장애요인으로 작용하여 화재의 크기 및 온도분포를 증가시키는 요인으로 나타났다.

• 터널과지하공간
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• 제9권1호
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• pp.1-11
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• 1999

열-수리-역학적 상호작용을 해석하기 위한 유한요소 코드가 개발되었다. 이 코드는 Noorishad(1984)에 의해 제시된 유한요소 수식화에 기초하였으며, 절리 거동은 Goodman 의 절리 구성 모델로 모사되었다. 개발된 코드가 각각 절리가 있거나 없는 두가지 종류의 수갱 모델에 대한 T-H-M 상호작용 해석에 적용되었다. 절 리가 없는 모델에 대해서, 수갱벽면으로부터 바깥 방향으로 온도 증가가 뚜렷이 나타났다. 절 리가 있는 모델에 대해서, 절리의 닫힘이 열팽창에 의해 생겼으며, 물이 암석기질보다 낮은 열 전도도와 높은 비열용량을 보이기 때문에 절리를 따라 온도 분포가 상대적으로 낮게 나타났다. 또한 절리 내에서의 열 유동의 영향이 암반내에서의 수리유동의 영향보다 더 크다고 결론내릴 수 있다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.1033-1036
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• 2002

Wafer bonding methods such as fusion and anodic bonding suffer from high temperature treatment, long processing time, and possible damage to the micro-scale sensor or actuators. In the localized bonding process, beating was conducted locally while the whole wafer is maintained at a relatively low temperature. But previous research of localized heating has some problems, such as non-uniform soldering due to non-uniform heating and micro crack formation on the glass capsule by thermal stress effect. To address this non-uniformity problem, a new heater configuration is being proposed. By keeping several points on the heater strip at calculated and constant potential, more uniform heating, hence more reliable wafer bonding could be achieved. The proposed scheme has been successfully demonstrated, and the result shows that it will be very useful in hermetic packaging. Less than 0.2 ㎫ contact Pressure were used for bonding with 150 ㎃ current input for 50${\mu}{\textrm}{m}$ width, 2${\mu}{\textrm}{m}$ height and 8mm $\times$ 8mm, 5mm$\times$5mm, 3mm $\times$ 3mm sized phosphorus-doped poly-silicon micro heater. The temperature can be raised at the bonding region to 80$0^{\circ}C$, and it was enough to achieve a strong and reliable bonding in 3minutes. The IR camera test results show improved uniformity in heat distribution compared with conventional micro heaters. For gross leak check, IPA (Isopropanol Alcohol) was used. Since IPA has better wetability than water, it can easily penetrate small openings, and is more suitable for gross leak check. The pass ratio of bonded dies was 70%, for conventional localized heating, and 85% for newly developed FP scheme. The bonding strength was more than 30㎫ for FP scheme packaging, which shows that FP scheme can be a good candidate for micro scale hermetic packaging.