• 한국농림기상학회지
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• 제17권2호
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• pp.156-164
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• 2015

기후변화로 야기되는 미래의 고온 환경은 벼의 생산성을 저하시킬 것으로 예측되고 있다. 본 연구에서는 기후변화에 따른 국내 벼 생산성의 신뢰성 있는 영향평가 기초자료를 확보하기 위해 고온 환경에서의 벼의 수량과 수량 구성 요소의 반응을 조사하고 분석하였다. 실험은 1/5000a 와그너 포트를 이용하여 2008년과 2009년에 걸쳐 서울대학교 부속실험농장($37^{\circ}16^{\prime}N$, $128^{\circ}59^{\prime}E$)의 온도조절 플라스틱 하우스에서 실시되었다. 2008년에는 자포니카계의 화성벼를 공시품종으로 이용하였으며, 시비수준을 $120kg\;N\;ha^{-1}$와 $180kg\;N\;ha^{-1}$로 하였다. 온도처리는 대기온도, 대기온도 대비 $+1.5^{\circ}C$, $+3.0^{\circ}C$의 세 수준으로 하였다. 2009년에는 화성벼와 통일계의 다산벼를 공시품종으로 하여 $120kg\;N\;ha^{-1}$ 수준으로 시비하였다. 온도처리는 대기온도, 대기온도 대비 $+1.5^{\circ}C$, $+3.0^{\circ}C$ 및 $+5.0^{\circ}C$ 수준으로 처리하였다. 수량 및 수량구성요소의 온도처리에 따른 영향은 품종별로 상이한 반응을 보였다. 이삭수와 이삭당 영화수는 두 품종 모두 온도처리의 영향을 받지 않았으나, 천립중과 등숙률에 대해 화성벼는 $5.0^{\circ}C$, 다산벼는 $1.5^{\circ}C$ 이상의 온도처리에서 유의하게 감소하였다. 포트당 수량은 화성벼의 경우 $5.0^{\circ}C$, 다산벼는 $3.0^{\circ}C$ 및 $5.0^{\circ}C$ 온도처리에서 유의한 감소를 나타냈다. 등숙기간 동안의 평균기온에 대한 천립중과 등숙률 반응 또한 품종별로 다르게 나타났다. 다산벼의 경우 $23^{\circ}C$ 이상의 평균 온도에 대해 등숙률과 천립중이 급격히 감소한데 반해, 화성벼는 $23^{\circ}C$부터 $27^{\circ}C$ 범위에 대해 등숙률과 천립중의 변화가 크지 않았다. 기후변화에 의한 지속적인 기온상승이 예상되는 가운데 온도상승에 따른 등숙률과 천립중의 감소는 미래 기후 환경에서의 벼의 수량 감소를 야기하는 주요 원인으로 예측된다. 다만, 상승된 기온에 대한 벼의 반응은 품종별로 상이하기 때문에 고온에 둔감한 품종의 도입 또는 그러한 특성을 지닌 품종의 육종을 통해 기후변화에 따른 수량 감소의 위험을 낮출 수 있을 것이다.

• 산업기술연구
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• 제29권B호
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• pp.127-131
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• 2009

This paper presents the development of smart counting system that is proper for grains with uneven unit weight or shape. This device can detect the small differences of a light beam and count the pulse from wave shape control, when the grain is going on the light screen, which is made by the light beam screen sensor. It can, different from the former conventional device, distinct the uneven grains for counting detect, by using the dedicated hardware and the software algorithm of the light sensor.

• 한국작물학회지
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• 제36권2호
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• pp.166-173
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• 1991

출수후 등숙기간 동안에 엽신의 노화속도와 동화산물의 전류특성과의 관계를 구명하며 등숙향상 및 단기등숙 품종육성을 위한 선발지표를 제공코자 엽신의 노화정도가 다른 올보리외 29품종 및 계통을 공시하여 엽신 노화율, 등숙율 및 상호 상관관계를 조사하였던 바 결과를 요약하면 다음과 같다. 1. 엽신의 노화속도 및 입충전속도(등숙율)는 계통에 따라 큰 차이가 있었다 2. 등숙초ㆍ중기(출수후 10-20일) 및 등숙중ㆍ후기(출수후 20-30일)의 엽신 노화율과 해당 각 시기의 등숙율과는 높은 정의 상관관계가 있었다. 3. 등숙초ㆍ중기의 엽신 노화율과 등숙전기간(출수후 10-35일)의 등숙율과는 부의 상관이 등숙중ㆍ후기의 엽신 노화율과는 고도의 정의 상관관계가 있었다. 4. 입중과 등숙중ㆍ후기 및 등숙전기간의 등숙율과는 고도의 정의 상관관계가 있었으나 등숙초ㆍ중기의 등숙율 및 등숙일수와는 상관이 없었다. 5. 노화지수의 감소 양상은 계통에 따라 4가지 유형으로 분류할 수 있었는데 종실수량 및 등숙율면에서 가장 이상적인 유형은 IV형이었다 6. 본 시험결과 단기등숙형 대맥 품종으로 가장 이상적인 형은 등숙초ㆍ중기에는 노화지수가 높으면서도 노화속도가 느리나 등숙중ㆍ후기에는 노화속도가 빠른 품종임이 구명되었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.170-170
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• 2022

Grain filling traits of rice were traced to determine the critical temperature that ceased grain filling process, from the late transplanted temperate rice varieties in the field conditions of2020 and 2021. The tested three varieties were transplanted six times with four target heading dates of 20 Aug. (control), 10 Sep., 20 Sep. and 30 Sep. Nine times of sampling were made from a week after heading with three replicates for each treatment. Development of grain filling percentage, grain dry weight and milled rice weight demonstrated sigmoid curves in the first and second transplants of 2020, and in the first to third transplants of 2021. The three grain filling traits in the 2020 third transplants and in the 2021 fourth transplants initially increased with the progress of grain development, and reached the peaks at certain time points, then decreased thereafter. Non-linear regression analyses, performed for the traits in the transplants that showed sigmoid curves except control, indicated that 95% of the final data (95% FD) was attained when the seven-day moving temperature (Sd-MovT) was 8.4-9.6℃, which excluded the cases when the temperature before the dates of 95% FD was lower than that on the dates of 95% FD. Sd-MovT on the date of peak data was 8.5-9.8℃ in the 2020 third transplants and 6.9-8.3℃ in the 2021 fourth transplants. Grain development was observed when seven-day mean temperature (Sd-MT) from 35 to 41 days after heading date was 9.4-10.8℃ in the 2020 third transplants and 10.1-11.9℃ in the 2021 fourth transplants. But Sd-MT of 8.7-9.1℃ in 2020 and 6.9-7.6℃ in 2021, at 42-48 days after heading, resulted in no progress of grain development. Overall, Sd-MovT at the point of stagnated grain development appeared in the range of 6.9-9.8℃. The lowest Sd-MT that showed the progress of grain development was 9.4-9.5℃ and the highest Sd-MT that showed no grain development was 9.1℃, both of which appeared in Odae and Haiami of the 2020 third transplants Therefore it is concluded that critical temperature for the grain development of temperate rice in natural conditions exists between 9.1℃ and 9.5℃.

• Asian-Australasian Journal of Animal Sciences
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• 제9권6호
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• pp.647-650
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• 1996

Fifteen sheep were used in a trial which compared the feeding value of whole barley gain and cottonseed cake as supplements to a basal diet of leaves of fourwing saltbush (Atriplex canescens). Diet SB contained 700 g (air-dry matter) of saltbush alone, diet SB + BG contained 700 g SB with 400 g whole barley grain and diet SB + CS contained 700 g SB with 400 g cottonseed cake. The digestibility of the dry matter of diets SB (69%) and SB + CS (70%) were lower (p < 0.001) than of diet SB + BG (76%). Sheep offered SB alone daily lost 80g whereas those fed the other diets gained 11 g (SB + CS) or 17 g (SB + BG) per day. Daily water consumption of the sheep offered the three diets was similar (p > 0.05), but their water consumption was higher (p < 0.001) than that of sheep offered daily 700 g wheat straw and 200 g barley grain. The results indicate that, at the levels of feeding used, barley grain and cottonseed cake had similar value as supplements to fourwing saltbush harvested in summer. The addition of the supplement allowed the sheep to gain some live weight. However, the presence of saltbush leaves in the diet resulted in higher water intakes by the sheep.

• 한국자원식물학회지
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• 제11권2호
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• pp.152-156
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• 1998

This experiment was conducted to investigated the characteristics of grain appearance, chemical components. gelatinization, and palatability of cooked rice on each rachis branches as harvested from the transplanting plot of May 20 and June 5 in each two varieties of early-maturing and late-maturing types. In evaluation of rachis branches, the percentage of ripended grain and 1,000 grain weight were found to be high and heavy at upper part of panicle. The factors influencing palatability such as maximum viscosity and breakdown as gelatinization characteristics, and hardness, apringiness, cohesiveness and chewiness as texture characteristics of cooked rice were found to be high at upper part of panicle , indicating the parlability was favored more at upper part than at lower part of panicle due to the genetics and physiological metabolism of rice plants.

• 한국세라믹학회지
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• 제51권2호
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• pp.127-131
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• 2014

Precipitated calcium carbonate(PCC) inorganic fillers for plastic offera higher replacement ratio with improved mechanical properties than any other inorganic fillers. Due to its secure economic feasibility, its fields of application areexpanding. For optimized PCC grain size and polymer replacement ratio, it is good to maintain at least $0.035{\mu}m$ grains and keep double the grain size of distance between particles, depending on the molecular weight and volume replacement rate of the polymer. PCC has unique characteristics, ie, with smaller grain size, dispersibility decreases, and if grain size is not homogenous, polymer cracking occurs. The maximum replacement ratio of PCC is approximately 30%, but in the range of 10 - 15% it produces the highest mechanical strength. When mixed with a biodegradable plastic like starch, it also improves initial environmental degradability.

• Advances in materials Research
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• 제7권2호
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• pp.105-118
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• 2018

Magnesium and its alloys are attracted towards all engineering applications like automotive, marine, aerospace etc. due to its inherent high strength to weight ratio. But, extensive use of Mg alloys is limited to the current scenario because of low wear and corrosion resistance behavior. However, equal channel angular press is one of the severe plastic deformation technique which has been effective method to improve the wear and corrosion resistance by achieving fine grain structure. In this study, the effect of grain refinement on wear and corrosion resistance of AZ80 Mg alloys were investigated. The wear behavior of the coarse and fine-grained Mg alloys was examined through $L_9$ orthogonal array experiments in order to comprehend the wear behavior under varies control parameters. It was shown that ECAPed alloy increased the wear and corrosion resistance of the Mg alloy through the formation of fine grain and uniform distribution of secondary ${\beta}-phase$. Also, the performance of AZ80 Mg alloy for these changeswas discussed through SEM morphology.

• Asian-Australasian Journal of Animal Sciences
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• 제15권2호
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• pp.188-194
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• 2002

To study the effect of wheat bran and lactic acid producing bacteria (LAB) on the performance of calves, 20 crossbred male cattle calves (day old), distributed into two groups were fed on calf starters containing 50 or 0% maize grain, along with green berseem ad libitum and milk as per body weight. Each group was further divided into two sub groups and one subgroup of each group was supplemented with mixed culture of LAB (Lactobacillus acidophilus L. casei, L. Jugarti). Milk feeding was discontinued after 8 weeks of age. The addition of culture increased (p<0.05) DM intake in calves receiving grainless diet from eighth week to the thirteenth one. There was about 21% higher body weight gain and 14% lower feed : gain ratio in culture supplemented calves. DM digestibility was significantly lower (p<0.05) in calves getting grain without culture. The crude protein NDF and ADF digestibility was higher (p<0.05) in grainless than the grain fed group. No major change on rumen fermentation pattern among different treatments was found. The concentration of total volatile fatty acids (TVFA) and protozoa count was higher (p<0.05) in grain fed group. However, lactic acid concentration was higher and rumen pH was lower due to culture feeding. The incidence as well as severity of diarrhoea was reduced in culture supplemented group. The results indicate that crossbred calves can be reared successfully on grainless diet and berseen fodder. The performance of calves was also improved by LAB supplementation.

• Journal of Biosystems Engineering
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• 제9권2호
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• pp.65-73
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• 1984

While most of researches on the performance of high temperature grain dryer have dealt mainly with improving dryer capacity and drying speed during the last twenty years, energy efficiency, in fact, has not been emphasized. Current fuel supplies and energy cost have shifted the emphasis to reducing the energy consumption for grain drying while maintaining dryer capacity and grain quality. Since the energy input for drying is relatively large, the recovery and reuse of at least part of the exhaust energy can significantly reduce the total energy consumption in existing drying systems. Unilization of exhaust heat in grain dryer either through direct recycling or by a thermal coupling in heat exchanger have been subject of a number of investigators. However, very seldom research in Korea has been done in this area. Three drying tests(non-recycling, 0.22 recycle ratio, and 0.76 recycle ratio)were performed to investigate the thermal efficiency and heat loss factors of continuous flow type dryer, and to analyze the effect of recycle ratio (weight of exhaust air recycled/total weight of input air) on the energy requriements for rough rice drying. The test results showed that when the exhaust air was not recycled, the energy lost from furnace was 15.3 percent of input fuel energy, and latent and sensible heat of exhaust air were 61.4 percent and 11.2 percent respectively. The heat which was required in raising grain temperature and stored in dryer was relatively small. As the recycle ratio of exhaust air was increased, the drying rate was suddenly decreased, and thermal efficiency of the kerosene burner was also decreased. Drying test with 0.76 recycle ratio resulted in 12.4% increase in fuel consumption, and 38.4% increase in electric power consumption as compared to the non-recycled drying test. Drying test of 0.22 recycle ratio resulted in 6.8% saving in total energy consumption, 8.0% reduction in fuel consumption, and 2.5% increase in electric power consumption as compared to the non-recycled drying test.