• 한국식품영양학회지
• /
• 제5권1호
• /
• pp.13-22
• /
• 1992

This study was divised to observe the inhibitory effect of growth rate of human colon cancer cells by Eucommial leaf extract, in vitro. Three species of human colon cancer cells, HRT-18, HCT-48 and HT-29, were used for the experiment. Each extract of Eucommial leaf was prepared by extraction with water, 95% alcohol, acetone, chloroform and petroleum ether, and then the inhibitory effect of each extract on the growth rate of cells was compared with control group and each other. The experimental results obtained are summarized as follows; 1. Inhibitory effects on growth rate of human colon cancer fells were strongest in the petroleum ether extract and next in the chloroform extract. 2. Inhibitory effects on the growth rate of the cancer cells by extracts of water, 95% alcohol and acetone were weaker than that of petroleum ether and chloroform. 3. Inhibitory effect of each extract on the cancer cell growth was shown most strong activity in HT-29, and was in order of HRT 18 and HCT-48. In view of the results, it could be suggested that inhibitory effects of non-polar solvent's extracts against the cancer cell growth were more stronger than that of polar solvents and the effects were indicated difference according to the species of the cells.

• 자원ㆍ환경경제연구
• /
• 제12권3호
• /
• pp.515-529
• /
• 2003

본 연구는 자본과 노동의 요소투입물의 증가가 환경오염의 증가를 유발한다는 Byrne (1997)모형과 기술축적도 환경오염을 유발하는 Bovenberg and Smulders (1995)모형을 혼합한 이론적 모형을 구축하고 경제성장률 제약조건식을 도출하여 경제성장과 환경오염관련 변수 간의 관계를 실증분석하였다. 도출된 경제성장률 조건식에서 경제성장률은 상대적인 소비와 오염의 비효용이 감소할수록, 할인율이 감소할수록, 오염저감기술수준이 증가할수록, 기술생산성 파라메타가 증가할수록 증가함을 보였다. OECD 20개국 패널자료를 이용한 실증분석에서 노동생산성이나 총고정자본, 기술이전과 같은 성장관련 주요 변수들은 모두 유의한 것으로 나타나 경제성장 관련 기존의 연구결과와 다르지 않았다. 그러나 경제성장에 대한 환경오염변수의 추정계수가 유의한 값으로 나타나지 않아 이론적으로 도출한 경제성장률조건식의 설명에 한계가 있으나 오히려 환경쿠즈네츠곡선가설의 존재여부를 판단할 수 있는 실증분석 연구과제를 남기는 데 의미가 있다고 본다.

• 한국패류학회지
• /
• 제30권3호
• /
• pp.227-234
• /
• 2014

본 연구는 해상가두리의 먹이공급비율에 따른 성장 및 생존율을 조사하고, 실내육상양식의 먹이 공급율과의 비교를 통해 국내 주요 북방전복 양성방법인 해상가두리와 함께 실내 사육 수조의 적정 천연먹이의 공급율을 제안하여 북방전복 생산성 향상을 유도하고자 실시하였다. 먹이공급율은 전복 어체중량을 기준으로 일간공급율 (daily feeding rate, DFR) 5, 10, 15, 20% (5DFR, 10DFR, 15DFR, 20DFR) 를 설정하여, 해상가두리와 실내육상수조에서 2반복으로 13개월간 실시하였다. 해상가두리에서 사육한 전복 (최초 수용 시 평균각장 $54.18{\pm}7.39mm$) 성장에서 각 장과 각폭의 절대성장율 (absolute growth rate, ARG), 일간 성장율 (daily growth rate, DGR) 및 특수생장율 (specific growth rate, SGR) 과 중량의 증중률 (weight gain, WG), 일간증중률 (daily weight gain, DWG) 및 특수증중률(specific weight gain, SWG), 그리고 생존율에서 20DFR이 유의적으로 낮았다 (P < 0.05). 실내육상수조에서 사육한 전복 (최초 수용 시 평균각장 $49.70{\pm}2.28mm$) 의 각장, 각폭의 ARG, DGR, SGR과 중량의 WG, DWG, SWG에서는 5DFR, 10DFR이 유의적으로 높았고 (P < 0.05), 생존율은 20DFR이 유의적으로 낮았다 (P < 0.05). 따라서 해상가두리와 실내육상수조 전복양식 자연먹이의 일간 공급율은 성장과 생존율, 그리고 경제적 측면까지 고려하면 어체중량의 5-10%에서 공급해야 한다.

• 한국어병학회지
• /
• 제17권1호
• /
• pp.67-74
• /
• 2004

범게, Orithyia sinica 유생을 대상으로 암모니아와 아질산에 대한 생존 및 성장에 관한 실험을 실시하였다. 암모니아 노출 실험구에서 zoea기 유생은 노출 20일후, 대조구가 80%의 생존율을 나타내었지만 10 mg/L 이상의 실험구에서는 37-45%의 생존율을 나타내었고, megalopa기 유생에서도 유사한 경향을 나타내었다. 암모니아가 범게 유생의 성장에 미치는 영향을 조사한 결과, zoea기 유생은 20 mg/L 이상의 농도에서 megalopa기 유생은 50 mg/L 이상의 농도에서 유의한 차이를 나타내었다 (P<0.05). 아질산 노출실험에서는 zoea기 유생과 megalopa기 유생에서 농도와 노출기간에 비례하여 생존율이 감소하였으며, 특히 150 mg/L 이상의 아질산 농도에 노출된 zoea기 유생과 megalopa기 유생은 대조구와 비교하여 유의한 성장 지연을 나타내었다.(P<0.05)

• 한국전기전자재료학회논문지
• /
• 제19권4호
• /
• pp.344-349
• /
• 2006

A sublimation epitaxial method, referred to as the Closed Space Technique (CST) was adopted to produce thick SiC epitaxial layers for power device applications. We aimed to systematically investigate the dependence of SiC epilayer quality and growth rate during the sublimation growth using the CST method on various process parameters such as the growth temperature and working pressure. The etched surface of a SiC epitaxial layer grown with low growth rate $(30{\mu}m/h)$ exhibited low etch pit density (EPD) of ${\sim}2000/cm^2$ and a low micropipe density (MPD) of $2/cm^2$. The etched surface of a SiC epitaxial layer grown with high growth rate (above $100{\mu}m/h$) contained a high EPD of ${\sim}3500/cm^2$ and a high MPD of ${\sim}500/cm^2$, which indicates that high growth rate aids the formation of dislocations and micropipes in the epitaxial layer. We also investigated the Schottky barrier diode (SBD) characteristics including a carrier density and depletion layer for Ni/SiC structure and finally proposed a MESFET device fabricated by using selective epilayer process.

• Fisheries and Aquatic Sciences
• /
• 제8권2호
• /
• pp.90-96
• /
• 2005

The larvae of Palaemon gravieri were reared in the laboratory at three different temperature regimes ($15^{\circ}C,\;20^{\circ}C,\;and\;25^{\circ}C$) with the salinity ranges (28-32 psu) to understand how temperature and body size influence survival rate, and growth components (molt increment and intermolt period). The optimum temperature for the highest survival rate was $25^{\circ}C$. The intermolt periods consistently increased with an increase in size and instar number; however, the molt increments at successive instars generally decreased with an increase in size and instar number. The shortest intermolt period and the highest larval growth rate both occurred at $25^{\circ}C$. Thus, the optimum temperature for larval survival and growth rate was found to be $25^{\circ}C$ which was the temperature at which the larvae actually appear in nature.

• Environmental Engineering Research
• /
• 제20권4호
• /
• pp.347-355
• /
• 2015

The growth kinetics of phototrophic microorganisms can be controlled by the light irradiance, the concentration of an inorganic nutrient, or both. A multi-component kinetic model is proposed and tested in novel batch experiments that allow the kinetic parameters for each factor to be estimated independently. For the cyanobacterium Synechocystis sp. PCC6803, the estimated parameters are maximum specific growth rate $({\mu}_{max})=2.8/d$, half-maximum-rate light irradiance $(K_L)=11W/m^2$, half-inhibition-rate light irradiance $(K_{L,I})=39W/m^2$, and half-maximum-rate concentration for inorganic carbon $(K_{S,Ci})=0.5mgC/L$, half-maximum-rate concentration for inorganic nitrogen $(K_{S,Ni})=1.4mgN/L$, and half-maximum-rate concentration for inorganic phosphorus $(K_{S,Pi})=0.06mgP/L$. Compared to other phototrophs having ${\mu}max$ estimates, PCC6803 is a fast-growing r-strategist relying on reaction rate. Its half-maximum-rate and half-inhibition rate values identify the ranges of light irradiance and nutrient concentrations that PCC6803 needs to achieve a high specific growth rate to be a sustainable bioenergy source. To gain the advantages of its high maximum specific growth rate, PCC6803 needs to have moderate light illumination ($7-62W/m^2$ for ${\mu}_{syn}{\geq}1/d$) and relatively high nutrient concentrations: $N_i{\geq}2.3 mgN/L$, $P_i{\geq}0.1mgP/L$, and $C_i{\geq}1.0mgC/L$.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집A
• /
• pp.501-506
• /
• 2001

The creep crack growth properties in 3.5NiCrMoV steel were investigated at $550^{\circ}C$ by using CT specimen under constant $C_t$ condition that was held during crack growth of 1mm distance. $C_t$ lely on load line displacement rate and $C^*$ usually increase with crack length though load is reduced in order to maintain constant $C_t$ value as crack growth. Fully coalesced area(FCA) ahead of crack tip tend to increase as $C_t$ increase to the critical value, and after that value FCA decrease. For the tertiary creep stage of crack growth test, the most of displacement is due to the steady state creep, except only small part due to the primary creep and other effects. Therefore, tests were mainly interrupted in the tertiary stage to obtain high value of $C_t$. At constant load and $C_t$ region, crack growth slope was 0.900 and 0.844 each, on the other hand $C^*$ slope was 0.480.

• Current Photovoltaic Research
• /
• 제8권1호
• /
• pp.17-26
• /
• 2020

It is clear that monocrystalline Silicon (Si) ingots are the key raw material for semiconductors devices. In the present industries markets, most of monocrystalline Silicon (Si) ingots are made by Czochralski Process due to their advantages with low production cost and the big crystal diameters in comparison with other manufacturing process such as Float-Zone technique. However, the disadvantage of Czochralski Process is the presence of impurities such as oxygen or carbon from the quartz and graphite crucible which later will resulted in defects and then lowering the efficiency of Si wafer. The heat transfer plays an important role in the formation of Si ingots. However, the heat transfer generates convection in Si molten state which induces the defects in Si crystal. In this study, a crystal growth simulation software was used to optimize the Si crystal growth process. The furnace and system design were modified. The results showed the melt-crystal interface shape can affect the Si crystal growth rate and defect points. In this study, the defect points and desired interface shape were controlled by specific crystal growth rate condition.

• 한국환경복원기술학회지
• /
• 제19권1호
• /
• pp.13-23
• /
• 2016

This study was conducted to investigate the growth characteristics of warm-season turfgrasses and to find out suitable turfgrass species on Saemangeum reclaimed land. Twenty native zoysiagrass(Zoysia sinica, Z. matrella, Z. japonica, Medium-leaf type zoysiagrass(hybrid zoysiagrass)) and bermudagrass(Cynodon dactylon) collected from Korea were used in this study. Total stolon length and the number of stolon per square meter, relative growth rate of shoot and stolon, and coverage rate were analyzed for 2 year. C. dactylon showed not only the most growth response with high relative growth rate of shoot and stolon, which were 19.9% and 66.3%, but also resulted in higher level of turf visual quality compared to others. Whereas Z. japonica showed the least growth response with low relative growth rate of shoot and stolon, which were 2.4% and 0.7%. Although all warm-season turfgrasses took root and grew up well, there were different growth rates between the interspecies. Z. sinica 'Z2034', Z. matrella 'Z4091', Z. japonica 'Z1064', Medium-leaf type zoysiagrass 'ZN6019' and C. dactylon 'BN7014' were the greatest growth rate of shoot and stolon. These results will be useful for selecting salt tolerant breeding lines and also used to develop a turfgrass cultivar with strong salinity tolerance through continuous monitoring.