• Journal of Plant Biology
• /
• 제33권2호
• /
• pp.111-118
• /
• 1990

In order to characterize the chloroplasts of Korean ginseng as a semi-shade plant and radish as a sun plant, effects of growth light intensity on photosynthetic electron transport (PS) activity in chloroplasts and superoxide (O2.-) production in thylakoid membrane by irradiation were investigated. High-light chloroplasts of both plants showed higher PS activities than those grown under ow growth light intensity. High PS II and low PS I activities in ginseng chloroplasts (ratio of PS II/PS I : 1.1) were observed, but radish chloroplasts showed low PS II and high PS I activities (ratio of PS II/PS I : 0.3). PS II activity of both plants was little affected by temperature in range of 15-35$^{\circ}C$. Activities of whole -chain (PS II+I) in ginseng and PS I in radish were increased at high temperature (4$0^{\circ}C$). Preincubation of chloroplasts at 4$0^{\circ}C$ during 30 min, as a mild heat stress, caused rapid decrease in PS II and PS II+I activities of both plants. However PS I activity was not decreased in ginseng and rather increased in radish. O2.- production (NBT reduction) in Mehler reaction in the thylakoid membrane was inhibited by DCMU in both plants. DMBIB inhibited O2.- production in ginseng, but radish was insensitive to DMBIB. Electron flow system in ginseng thylakoid membrane was more susceptible to damage of photooxidation than that of radish.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
• /
• pp.473-474
• /
• 2010

C-S-H(I)은 활성슬래그시멘트의 강도생성의 핵심물질이며 시멘트 수화물의 강도원천물질인 C-S-H의 구조모델로 사용되어 왔기 때문에, 나노 수준의 콘크리트 연구 분야에서는 세계적으로 아주 중요한 물질로 다루어지고 있다. 이러한 C-S-H(I)에서 발생되는 Si에 대한 Al 치환은 C-S-H(I)의 분자구조변경을 인위적으로 할 수 있다는 점에서 주목되어 왔고, C-S-H(I)의 기계적 물성치 (예, bulk modulus)에도 큰 영향을 미칠 것이라고 예상되어 왔었다. 그러나 본 연구를 통해 이러한 Al 치환이 실제로는 C-S-H(I)의 bulk modulus에는 거의 영향을 미치지 못함이 밝혀졌다.

• 태양에너지
• /
• 제6권2호
• /
• pp.3-14
• /
• 1986

It is desirable to collect the solar thermal energy at relatively high temperature in order to minimize the size of thermal storage system and to enlarge the scope of solar thermal energy utilization. In this study, to develop a solar collector that has both advantages of collecting solar thermal energy at high temperature and fixing conveniently the collector system for long term period, a cylindrical parabolique concentrating solar collector (M.C.P.C.S.C) was designed, which has several rows of parabolique reflectors and thin thickness such as the flat-plate solar collector, maintaining the optical form of concentrating solar collector. The thermal performance of the M.C.P.C.S.C. newly designed in this study was analysed theoretically and experimentally. The results are summarized as follows: 1) prediction equation for outlet temperature, $T_o$, of heat transfer fluid and for the thermal efficiency, ${\eta}$, of the collector were derived as; o $$T_o=[C+B1_n(\frac{I_c(t)}{pv^3})]T_i$$ o $${\eta}=\frac{A}{A_c}\dot{m}[(C-1)+B1_n(E{\cdot}di^6\frac{I_c(t)}{\dot{m}^3})]\frac{T_i}{I_c(t)}$$ 2) When the insolation on the tilted solar collector surface, $I_c$, was $900-950W/m^2$ and the heat transfer fluid was not circulated in tubular absorber, the maximum temperature on the absorber surface was $100-118^{\circ}C$, this result suggested that the heat transfer fluid could be heated up to $98-116^{\circ}C$. The maximum temperature on the absorber surface was decreased with the increase of the collector shape factor, $L_p/L_w$ 3) There was a good agreement between the experimental and theoretical value of solar collector efficiency, ${\eta}$, which was proportional to the collector shape factor, $L_p/L_w$ 4) It is desirable to continue the study on the relationship between the collector shape factor, $L_p/L_w$, and the thermal efficiency of solar collector.

• Molecules and Cells
• /
• 제27권3호
• /
• pp.291-297
• /
• 2009

Apolipoprotein (apo) C-III is a marker protein of triacylglycerol (TG)-rich lipoproteins and high-density lipoproteins (HDL), and has been proposed as a risk factor of coronary heart disease. To compare the physiologic role of reconstituted HDL (rHDL) with or without apoC-III, we synthesized rHDL with molar ratios of apoA-I:apoC-III of 1:0, 1:0.5, 1:1, and 1:2. Increasing the apoC-III content in rHDL produced smaller rHDL particles with a lower number of apoA-I molecules. Furthermore, increasing the molar ratio of apoC-III in rHDL enhanced the surfactant-like properties and the ability to lyse dimyristoyl phosphatidylcholine. Furthermore, rHDL containing apoC-III was found to be more resistant to particle rearrangement in the presence of low-density lipoprotein (LDL) than rHDL that contained apoA-I alone. In addition, the lecithin:cholesterol acyltransferase (LCAT) activation ability was reduced as the apoC-III content of the rHDL increased; however, the CE transfer ability was not decreased by the increase of apoC-III. Finally, rHDL containing apoC-III aggravated the production of MDA in cell culture media, which led to increased cellular uptake of LDL. Thus, the addition of apoC-III to rHDL induced changes in the structural and functional properties of the rHDL, especially in particle size and rearrangement and LCAT activation. These alterations may lead to beneficial functions of HDL, which is involved in anti-atherogenic properties in the circulation.

• 대한화학회지
• /
• 제42권1호
• /
• pp.135-140
• /
• 1998

High oxygen pressures appear an important tool in Solid State Chemistry. Two main routes can be developed: (i) the stabilization of thermally unstable oxides, used as precursors, in order to open the synthesis of new materials, (ii) the stabilization of the highest oxidation states of transition metals. This paper is essentially devoted to this second research axis. The methodology developed for preparing new oxides containing Fe(Ⅴ), Ir(Ⅵ), high spin Fe(Ⅳ) and Cu(Ⅲ) is described.

• Journal of the Optical Society of Korea
• /
• 제13권4호
• /
• pp.464-467
• /
• 2009

The grating projection method with phase-shifting technique is very useful in measuring the 3-dimensional (3D) shape with high accuracy and speed. In this work, we have developed an ultra high-speed digital laser grating projection system using a high-power laser diode and a highsensitivity CMOS camera. With our system, the optical measurement required to find out the profile of a 3D object could be carried out within 2.6 ms, which is a significant ($\sim$10 times) improvement compared with those of the previous studies.

• 지질공학
• /
• 제32권4호
• /
• pp.671-684
• /
• 2022

본 연구에서는 고강도 결합 매입말뚝 흙막이 공법의 안정성을 검증하고 그에 따른 현장 적용성을 확인하고자 하였다. 따라서 C.I.P 흙막이 공법과 고강도 결합 매입말뚝 흙막이 공법을 수치해석으로 비교·분석하였으며, 고강도 결합 매입말뚝 흙막이 공법이 적용된 현장의 계측 Data와 수치해석 결과를 비교·분석하여 지반거동 및 고강도 결합 매입말뚝 흙막이 공법의 안정성 및 현장 적용성을 검증하고자 하였다. 실험결과, 단면력의 경우 고강도 결합 매입말뚝 흙막이벽이 C.I.P 흙막이벽보다 변위는 최소 13.6%~최대 19.7%가 감소하였고, 전단력은 최소 0.7%~최대 4.7% 정도 증가하였다. 또한 휨모멘트의 경우 최소 4.5%~최대 8.8%정도 증가하는 경향을 보였다. 굴착주변 지반의 침하량을 검토한 결과, C.I.P 흙막이벽이 최대 46.89 mm, 고강도 결합 매입말뚝 흙막이벽이 39.37 mm로 산정되었으며, 고강도 결합 매입말뚝이 C.I.P 흙막이벽에 비해 최대 침하량이 약 17% 정도 작게 산정되었다. 현장지반을 대상으로 탄소성보법에 의해 산정된 최대 휨모멘트와 전단력을 적용하여 고강도 결합 매입말뚝 흙막이벽체를 설계한 결과, 모두 탄성영역 내에서 부재력이 발생되어 안전한 것으로 나타났다.

• 한국수산과학회지
• /
• 제45권4호
• /
• pp.343-350
• /
• 2012

Even though the microalgal species of Isochrysis and Pavlova are widely used as live food in bivalve hatcheries, they are difficult to culture in mass during the summer season. Therefore, the present study was conducted to determine the optimum species or strains of Isochrysis and Pavlova to produce good growth and high contents of fatty acids at temperatures over $30^{\circ}C$. Four species of Isochrysis (I. galbana KMMCC12, I. galbana KMMCC214, I. aff. galbana, and Isochrysis sp.) and four of Pavlova (P. lutheri, P. gyrans, P. viridis, and Pavlova sp.) were cultured at $25^{\circ}C$, $29^{\circ}C$, and $33^{\circ}C$, and then analyzed for specific growth rate and fatty acid composition. Microalgae were cultured in f/2 medium at 23 psu and continuous light of $80{\mu}mol$ photons $m^{-2}s^{-1}$. For the I. galbana, growth rates were highest at $29^{\circ}C$ and decreased at $33^{\circ}C$ to the level observed at $25^{\circ}C$. I. galbana (KMMCC12) and Isochrysis sp. cultured at $29^{\circ}C$ and $33^{\circ}C$, respectively, exhibited the highest growth rates of all Isochrysis species. In terms of fatty acids, I. galbana (KMMCC12) contained higher contents of PUFA and n-3 HUFA at $33^{\circ}C$ than did Isochrysis sp. For species of Pavlova, growth rates of P. gyrans and P. viridis at $29^{\circ}C$ and $33^{\circ}C$, respectively, were higher than those of the other Pavlova species. In particular, P. viridis grew as well at $33^{\circ}C$ as it did at $29^{\circ}C$. However, P. lutheri and Pavlova sp. did not grow at $33^{\circ}C$. In terms of fatty acids, P. viridis cultured at $33^{\circ}C$ also exhibited higher contents of PUFA and n-3 HUFA, as compared to P. gyrans. Based on these results, we suggest that I. galbana (KMMCC12) and P. viridis are suitable species for mass culture during the high temperature season.

• 동의신경정신과학회지
• /
• 제4권1호
• /
• pp.99-119
• /
• 1993

In order to compare and examine the effect the effect of Kuibitang, Kamiondarmtang and Kuibiondarmtang against stress, I induced immobilization stress by binding rats for 200mins under a little anesthetized with ether. I classified as normal group, control group which administrated 0.9% NaCl solution, sample A group which administrated Kuibitang, sample B group which administrated Kamiondarmtang and sample C group which administrated Kuibiondarmtang. I got some conclusions by measuring amounts of norepinephrine, epinephrine, triiodothyronine($T_3$) and thyroxine($T_4$) in 1, 3 and 5 days, respectively. 1. Norepinephrine showed high meaningful decrease after 1. 3 and 5 days in sample A group. It showed little decrease in sample B group. It showed a little meaningful decrease after 1 day and high meaningful decrease after 3 and 5 days in sample C group. 2. Epinephrine showed high meaningful decrease after 3 and 5 days in sample A group. It showed little decrease in sample B group. It showed a little meaningful decrease after 3 days and high meaningful decrese after 5 days in sample C group. 3. Triiodothyronine($T_3$) inclined to approach normal value in sample A, B, C group in comparision wit control group but didn't have high meaning. 4. Thyroxine($T_4$) inclined to approach normal va1ue in sample A, B, C group in comparision with contrl group but didn't have high meaning. As I consider the effect of experiments, I think that Kuibitang and Kuibiondarmtang have some effects against stress and it is right to apply to the treatment of stress.

• Advances in concrete construction
• /
• 제10권2호
• /
• pp.113-125
• /
• 2020

This paper presents experimental results on bond-slip behavior of steel reinforced high-strength concrete (SRHC) after exposure to elevated temperatures. Three parameters were considered in this test: (a) high temperatures (i.e., 20℃, 200℃, 400℃, 600℃, 800℃); (b) concrete strength (i.e., C60, C70, C80); (c) anchorage length (i.e., 250 mm, 400 mm). A total of 17 SRHC specimens subjected to high temperatures were designed for push out test. The load-slip curves at the loading end and free end were obtained, the influence of various variation parameters on the ultimate bond strength and residual bond strength was analyzed, in addition, the influence of elevated temperatures on the invalidation mechanism was researched in details. Test results show that the shapes of load-slip curves at loading ends and free ends are similar. The ultimate bond strength and residual bond strength of SRHC decrease first and then recover partly with the temperature increasing. The bond strength is proportional to the concrete strength, and the bond strength is proportional to the anchoring length when the temperature is low, while the opposite situation occurs when the temperature is high. What's more, the bond damage of specimens with lower temperature develops earlier and faster than the specimens with higher temperature. From these experimental findings, the bond-slip constitutive formula of SRHC subjected to elevated temperatures is proposed, which fills well with test data.