• The Korean Journal of Rheology
• /
• v.6 no.2
• /
• pp.139-146
• /
• 1994

미연신, 비결정 PET 필름의 띠연신조건(띠연신 응력, 띠연신 온도, 띠열판의 상승속 도)에 따른 필름의거동을 연구하였다. 띠열판의 상승속도가 10, 20, 30, 50 mm/min일 때 온 도(Td) 이하에서는 임계네킹응력이 띠연신 온도가 증가함에 따라 급격히 감소하고 그 온도 이상에서는 거의 변하지 않고 일정했으며 임계온도 이하에서는 임계온도와 띠연신 온도의 온도차(Tc-Td)가 임계네킹응력과 비례관계를 가져 다음과 같은 간단한 실험식을 얻었다. $\sigma$c=0.838 (Tc-Td)+$\sigma$0 임계네킹응력에서 띠연신한 필름의 치수는 연신 온도와 띠열판의 상 승속도에 거의 의존하지 않고 일정한 값을 나타내었다. 임계네킹응력 이상에서는 연신 조건 에 따라 필름의 폭, 두께, 그리고 연신비가 거의 변하지 않았다.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.10a
• /
• pp.18-18
• /
• 2019

층실사초는 경북 북부를 포함한 강원도 지역의 습기있는 음지에서 자생한다. 여러해살이풀로서 주료 사료용으로 사용되며 지피식물 등 정원소재로도 사용된다. 본 연구는 층실사초의 대량증식을 위해 가장 효과적인 파종 시기를 구명하고자 수행하였다. 종자의 최적 발아조건을 찾기 위해 배양상 온도조건을 항온조건(30, 25, 20, 15, $5^{\circ}C$)과 변온조건(15/30, 20/10, $25/15^{\circ}C$) 총 8가지 조건으로 설정하여 발아율을 매일 측정하였다. 광조건은 형광등을 이용한 명조건과 암조건을 매일 12시간씩 반복하였다. 실험결과, 항온조건에서 발아율은 $25^{\circ}C$에서 $36{\pm}6.3%$로 가장 높게 나타났고, $20^{\circ}C$ ($27{\pm}4.4%$), $30^{\circ}C$ ($24{\pm}1.6%$) 순으로 나타났으며, $15^{\circ}C$, $5^{\circ}C$에서는 발아하지 않았다. 한편, 변온조건에서의 발아율은 $25/15^{\circ}C$에서 $22{\pm}7.3%$, $15/30^{\circ}C$에서 $10{\pm}2.5%$ 발아하였고, $20/10^{\circ}C$에서는 발아하지 않았다. 따라서 층실사초 종자의 발아최적온도는 $25^{\circ}C$이고 변온보다 항온이 유리했으며, 이 이상의 온도에서는 오히려 발아율이 낮아지는 것으로 나타났다. 이러한 결과를 바탕으로 가장 효과적인 파종 시기를 추정할 때, 낮 기온 $25^{\circ}C$의 초여름에 실시하되, 밤 기온이 너무 내려가지 않도록 조절해준다면 보다 높은 발아율을 기대할 수 있을 것으로 여겨진다. 그러나 본 연구결과, 최고 발아율이 $36{\pm}6.3%$로 비교적 낮기 때문에 발아율 향상을 위한 추가적인 실험이 필요할 것이다.

• 대한방사선치료학회:학술대회논문집
• /
• 1997.06a
• /
• pp.21-22
• /
• 1997

• Korean Journal of Food Science and Technology
• /
• v.20 no.3
• /
• pp.303-309
• /
• 1988

The heat generation at the start-up period of an autogeneous single screw extruder was determined with various feed materials, die structure and operational conditions. The highest heat generation rate was observed with defatted soybean meal, while the lowest value was obtained with rice flour, and wheat and barley flour showed the intermediate rate. As the moisture content of the flour decreased and the screw speed increased, the electric power requirement and heat generation rate increased. The temperature at compression section increased with the decrease in the particle size. The same effect was also observed as breaker plate was installed. The optimum operation was established as the temperature profile was maintained in decreasing order of metering section, die and compression section.

• Journal of Bio-Environment Control
• /
• v.18 no.4
• /
• pp.385-392
• /
• 2009

This study was performed to evaluate the influence of temperature, relative humidity, and light conditions during healing and acclimatization on the graft-take and growth of grafted peppers (Capsicum annuum L.), in order to propose optimum environmental conditions for the healing and acclimatization of grafted peppers. The healing and acclimatization period was for six days and was divided into three stages (Stage I, II and III), of which each period was two days. Grafted peppers were healed under the condition of 30 and 95% relative humidity (RH) during Stage I. During Stage II and III, grafted peppers were healed and acclimatized under different temperatures ($20^{\circ}C$, $25^{\circ}C$, or $30^{\circ}C$) and RH conditions (75%, 85% or 95%). The growth of grafted peppers was greater under lower temperature and lower relative humidity conditions. The graft-take just after the end of healing and acclimatization was greater grafted peppers under high RH condition. However, the graft-take of peppers which were healed and acclimatized under $30^{\circ}C$ and RH 95%, dropped by about 10 percent on day seven after healing and acclimatization. And also, grafted peppers were healed and acclimatized under the different temperatures ($25^{\circ}C$ or $30^{\circ}C$), RH conditions (65%, 75% or 85%), and light condition (dark or light). Lower RH (to 65%) and light condition at $25^{\circ}C$ during healing and acclimatization promoted the graft-take and growth of grafted peppers.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.19 no.4
• /
• pp.223-231
• /
• 2017

This study was conducted to determine the impact of elevated temperature based on climate change scenario on growth and bulb quality of extremely early-maturing onion (Allium cepa L. cv. Singsingball) in the temperature gradient tunnels. There were treated with 3 groups, one is a control group (ambient temperature, mean temperature at $9.8^{\circ}C$), another ambient temperature $+2^{\circ}C$ (mean temperature at $12.0^{\circ}C$), and the other ambient temperature $+5^{\circ}C$ (mean temperature at $14.3^{\circ}C$). Compared with the control, plant height, neck diameter, leaf area, top fresh weight and dry weight were significantly increased at ambient $+2^{\circ}C$ temperature. Bulb diameter and bulb weight was highest at ambient $+2^{\circ}C$ temperature (mean temperature at $12.0^{\circ}C$) during the growth period. Bulb/neck diameter ratio, over 2.0 a good indicator of development of bulb, increased rapidly at ambient $+2^{\circ}C$ temperature. This result suggests that extremely early-maturing onion (Allium cepa L. cv. Singsingball) could maintain the higher productivity and bulb quality at ambient $+2^{\circ}C$ temperature. On the contrary, $5^{\circ}C$ higher than atmospheric temperature shows negative effects on yields under a future climate change scenario.

• The Korean Journal of Food And Nutrition
• /
• v.29 no.2
• /
• pp.228-236
• /
• 2016

The purpose of this study was to determine the optimum conditions of solvent extraction type and solvent concentration (60, 70, 80%, v/v), extraction time (30, 80, 130 mins) and extraction temperature (10, 15, $20^{\circ}C$) in order to increase the antioxidant activity of the chia seed. The total polyphenol content and DPPH radical scavenging activity was measured by using response surface methodology (RSM) to establish the optimal conditions. Using ethanol and methanol extractions at extraction concentrations of 60%, and time and temperature of 130 mins and $20^{\circ}C$, the maximum total polyphenol content was 871.00 mg% ($R^2=0.9507$) and 557.70 mg% ($R^2=0.9784$) for ethanol and methanol extraction respectively. Using the same extraction conditions, the maximum level of DPPH radical scavenging activity was 72.14% ($R^2=0.9675$) and 52.79% ($R^2=0.9524$) for ethanol and methanol extraction respectively. The results indicate that ethanol extracts showed a higher antioxidant activity than methanol extracts. The ethanol extraction conditions of response surface analysis (RSA) were affected more by ethanol concentration than by extraction time or temperature. In contrast, the methanol extraction conditions of response surface analysis (RSA) were affected more by extraction time. Based on the RSM, the optimum ethanol extraction conditions were the following: extraction concentration, 63%: time, 100 mins: and temperature, $18^{\circ}C$. The optimum methanol extraction conditions were the following: extraction concentration, 65%; time, 120 mins; and temperature, $16^{\circ}C$.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.10a
• /
• pp.14-14
• /
• 2019

참삿갓사초는 전국에 분포하는 여러해살이풀로 사료용, 사방용 소재로 사용되며 조경용, 관상용 지피식물로 사용되기도 한다. 참삿갓사초의 대량증식을 위해 가장 효과적인 파종 시기를 추정하기 위해 생장상을 이용해 인공적인 온도조건을 주고 참삿갓사초 종자의 발아율을 조사하였다. 실험을 위해 온도를 항온조건(30, 25, 20, 15, $5^{\circ}C$)과 변온조건(15/30, 20/10, $25/15^{\circ}C$) 총 8가지 조건으로 설정하여 발아율을 매일 측정하였다. 광조건은 명/암을 매일 12시간씩 반복하였다. 항온조건에서 발아율은 $20^{\circ}C$가 $17{\pm}7%$로 가장 우수하였고, $25^{\circ}C$ ($12{\pm}2.8%$), $30^{\circ}C$ ($3{\pm}1.9%$) 순으로 나타났으며, $15^{\circ}C$, $5^{\circ}C$에서는 발아하지 않았다. 그러나 $20^{\circ}C$와 $25^{\circ}C$조건에서 통계적인 유의차는 발생되지 않았다. 한편, 변온조건에서의 발아율은 $15/30^{\circ}C$가 $91{\pm}3.8%$로 가장 우수하였고, $25/15^{\circ}C$ ($89{\pm}4.1%$), $20/10^{\circ}C$ ($69{\pm}3.4%$) 순으로 나타났다. 그러나 $15/30^{\circ}C$와 $25/15^{\circ}C$조건에서 통계적인 유의차는 발생되지 않았다. 따라서 참삿갓사초의 종자발아를 위해서는 변온이 필요하며, $25^{\circ}C$ 이상의 온도가 필요하다. 이러한 결과를 바탕으로 가장 효과적인 파종 시기를 추정할 때, 낮-밤 $10^{\circ}C$ 이상의 기온차가 있는 초여름~늦여름 사이가 가장 적절할 것으로 판단된다.

• Korean Journal of Agricultural Science
• /
• v.8 no.1
• /
• pp.29-43
• /
• 1981

The effects of temperature and day length during seed formation on the morphogenesis of lettuce seed were investigated using two cultivars of MSU 15 and MSU 16. Seed size and weight, and thickness of seed coat o f both cultivars greatly influenced by temperature, but fresh weights and dry matter weights of mother plants were influenced by day length, not by temperature. Interactions between the adaptive polymorphism and climatic conditions were also discussed. Environmental conditions affected the morphology of lettuce seed and this variation of seed morphology resulted from interaction between genetic potentialities and environmental conditions.

• Korean Journal of Environment and Ecology
• /
• v.12 no.1
• /
• pp.9-13
• /
• 1998

Because Lysimachia mauritiana is not able to maintain the seed viablity for a long time, it has difficulties in using for the ornamental plants or landscape gardening. This study was conducted to elucidate the optimal germination conditions of Lysimachia mauritiana seeds. The germination rate of the seeds was higer in light condition than in dark one. In experment determining the proper germination temperature, the germination rates were 2.2%, 96.9% and 91.2% under 35$\circ $C, 25$\circ $C, and 20$\circ $C, respectively in light condition. The approprate temperature for the germination was 25$\circ $C in light. The decreases of germination rate with the increase of the preservation periods was able to recover by priming pretreated with NaCl solution and KNO$_{3}$ + K$_{3}$H$_{2}$PO mixed solutions. When the storage period was 300 days, the germination rate was 75% without priming treatments. But the seeds primed with NaCl 0.1M and KNO$_{3}$ + K$_{3}$H$_{2}$PO mixed solutions 0.1M, showed germination rate above 90%. T$_{50}$ also was shorten from 5.25 without priming to 3.78 with NaCl 0.1M. Seed priming may induce earlier sprouts and increase germination rate of long-preserved seeds of native wild plants.