• 한국초지조사료학회지
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• 제17권1호
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• pp.27-34
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• 1997

This experiment was carried out to determine growth characteristics, dry matter (DM) yield, seasonal yield distribution and nutritive value of early- and late maturity orchardgrass, 1990 to 1992. The cultivars used in this study were Potomac, Hallmark (early maturing cultivar) and Lidacta, Rancho (late maturing cultivar), and a mixture plot (Potomac 25% + Hallmark 25% + Lidacta 25% + Rancho 25%) was involved. The seeding rate was 20 kgha in all treatments. Plant height of Potomac and Hallmark was longer than that of Lidacta and Rancho. The dates of initial heading and 50% heading of early maturing cultivars (Apr. 30 and May 10) were 10 days earlier than those of late matuing cultivars. Potomac and Hallmark were upright, and Lidacta and Rancho were semi-upright type, and severe disease and weeds (30 ~ 40%) were observed at Lidacta plot. On an average of three years, the DM yields of Potomac (10,549 kglna), Hallmark (10,435 kg) and mixture (10,356 kg) were significantly (P<0.05) higher than those of Rancho (9,457 kg) and Lidacta (8,218 kg). However, seasonal yield distribution of late maturing cultivars was better than that of early maturing cultivars. The contents of crude protein, crude fat, crude fiber, nitrogen %ee extract, aude ash, neutral detergent fiber, P, K, Ca, and Mg were not significantly different between cultivars, but higher aude protein yield was found at Potomac, Hallmark and mixture plots. Based on the above results, it may be concluded that early maturing cultivars for high productivity, late maturing cultivars for seasonal yield distribution, and seeding of mixture andlor separation of early- and late maturing cultivars are recommended. Also Lidacta was a not promising cultivar due to low productivity, severe disease, and high weeds development.

• 한국초지조사료학회지
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• 제37권2호
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• pp.101-107
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• 2017

Corn is basal forage for livestock species in Republic of Korea but it lacks protein and needs nitrogenous fertilizer. This study was designed with main objective to achieve optimum growth, yield & nutritive value of forage for livestock through implementing corn-soybean intercropping strategy at 17 different places under Korean condition. Two treatments; corn as monocrop (control treatment) and corn-soybean intercrop were compared under Randomized Block Design from $28^{th}$ May to $8^{th}$ October, 2015. Each treatment had three replicates in each block, whereas seventeen different places were considered as blocks. Data were analyzed through SAS-9.1.3 software. Difference between two treatment means was tested through T-test. Findings depicted that intercropping pattern could not influence (P>0.05) corn plant & ear height, corn lodged stalk No. and corn stalks number. However, corn-soybean intercropping enhanced (P<0.05) forage productivity in terms of total fresh yield ($16.4{\pm}0.7^b$ vs. $19.9{\pm}0.7^atons\;ha^{-1}$), total dry matter yield ($5.38{\pm}0.25^b$ vs. $6.41{\pm}0.31^atons\;ha^{-1}$) and total digestible nutrients yield ($3.94{\pm}0.17^b$ vs. $4.59{\pm}0.21^atons\;ha^{-1}$). Dry matter percentage in corn stalks and corn ears was not different (P>0.05) between two treatments. It was concluded that corn-soybean intercropping strategy was promising technique in enhancing forage productivity though positive symbiotic relation between two crops.

• 한국초지조사료학회지
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• 제16권1호
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• pp.75-80
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• 1996

The corn is one of the most important forage crop in Korea. The harvest time for silage affects dry matter (DM) yield and silage quality. This study was carried out to determine the effect of harvest time on the DM yield and nutritive value of corn forage at the Experimental Livestock Farm, College of Agriculture and Life Sciences, Seoul National University, Suweon in 1991. Forage DM yield and DM content of corn forage significantly increased mainly due to increase of ear. And also the ear to total DM ratio increased from 30% to 55% as the harvest was delayed. Chemical composition of the corn forage was improved by reduction in crude fihr, neutral detergent fiber and acid detergent fiber as the harvest was delayed. This results indicated that the harvest time of corn forage plays an important role to determine DM yield and DM contents for silage materials.

• Structural Engineering and Mechanics
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• 제58권4호
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• pp.719-729
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• 2016

The main objective of the present paper is to study the effect of the yield criterion on the magnitude of the strain rate and plastic work rate intensity factors in axisymmetric flow of isotropic incompressible rigid perfectly plastic material by means of a problem permitting a closed-form solution. The boundary value problem consisting of the axisymmetric deformation of a plastic tube is solved. The outer surface of the tube contracts. The radius of the inner surface does not change. The material of the tube obeys quite a general yield criterion and its associated flow rule. The maximum friction law is assumed at the inner surface of the tube. Therefore, the velocity field is singular near this surface. In particular, the strain rate and plastic work rate intensity factors are derived from the solution. It is shown that the strain rate intensity factor does not depend on the yield criterion but the plastic work rate intensity factor does.

• Structural Engineering and Mechanics
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• 제58권4호
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• pp.661-676
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• 2016

This paper presents an elastic/plastic model that neglects strain hardening during loading, but accounts for the Bauschinger effect. These mathematical features of the model represent reasonably well the actual behavior of several materials such as high strength steels. Previous attempts to describe the behavior of this kind of materials have been restricted to a class of boundary value problems in which the state of stress in the plastic region is completely controlled by the yield stress in tension or torsion. In particular, the yield stress is supposed to be constant during loading and the forward plastic strain reduces the yield stress to be used to describe reversed yielding. The new model generalizes this approach on plane stress problems assuming that the material obeys the von Mises yield criterion during loading. Then, the model is adopted to describe reversed yielding in thin hollow discs subject to external pressure.

• 한국식품영양학회지
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• 제12권5호
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• pp.484-489
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• 1999

Rosting conditions for improvement of viscosity and sensory properties of sea tangle extracts were investigated. The supernatant % solid yield and crude protein yield were increased by increasing of roasting temperature and times. The highest contents of algin was obtained in roasting temperature of 175$^{\circ}C$ ash contents were increased by roasting temperature increasing. Viscosities of sea tangle extract were significantly decreased by increasing of roasting temperature and time upto 175$^{\circ}C$ and 10 mins more than further roasting conditions. The pH of sea tangle extracts slightly decreased from 5.94 to 5.83 in the roasting of 15$0^{\circ}C$ however at temperature more than 175$^{\circ}C$ its pH was increased by increasing of temperature and time. According to increase of roasting temperature and time Lightness (L value) were significantly decreased and redness (a value) and yellowness (b value) reached the highest value in the roasting of 20$0^{\circ}C$ 15 min. or 175$^{\circ}C$ 30 min and after that its value were decreased. The odor characteristics showed that sea tangle extract prepared by roasting of 175$^{\circ}C$ 10mins was slightly reduced in intensity of savory and seaweed taste but significantly low in intensity of nauseous taste and high in intensity of roasted taste and accetability. Overall data suggested 175$^{\circ}C$ 10min was the most effective roasting conditions for improvement of viscosity and sensory properties of sea tangle extract.

• 한국작물학회지
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• 제48권6호
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• pp.534-539
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• 2003

이앙기 및 수확시기에 따른 쌀 품질을 식미 관점에서 검토하여 고품질 쌀 생산을 위한 기초 자료를 얻고자 2001년 서진벼, 일품벼, 추청벼를 공시하여 인천광역시 서구 경서동에 위치한 농업기반공사 김포간척지에서 실험한 결과는 다음과 같다. 1. 현미수량은 이앙시기간 고도로 유의한 차이가 있어서 3품종 모두 조기, 보통기재배가 만기재배보다 수량이 유의하게 많았다. 2. 백미의 단백질 함량은 이앙기와 수확시기간 고도의 상호작용이 있어서 발의 단백질 함량이 저하되는 수확시기는 이앙기에 따라 달랐다. 3. 이앙기에 따른 식미값은 서진벼와 일품벼는 조기와 만기재배에서 유의하게 높으나 추청벼는 만기재배에서도 떨어지지 않는 경향이었다. 4. 백미의 식미치는 등숙적산기온과 고도로 유의한 부의 상관(-0.43$^{**}$ )이 있어서 적산기온이 높을수록 식미치가 저하하였다. 5. 수량과 품질을 동시에 고려할때 조기 또는 보통기재배를 하되 수확시기는 출수후 40일로 다소 빠르게 하는 것이 유리한 것으로 판단되었다.

• 한국작물학회지
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• 제22권2호
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• pp.59-64
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• 1977

우리나라에서의 소맥 수량성과 품질의 지역성을 파악할 목적으로 9개 품종을 8개 지역에 공시한 국장시험에서 종실수량 및 소맥분의 단백질 함량과 침전가를 검토하여 이들 상호간의 관계를 품종 및 지역별로 검토한 결과는 다음과 같다. 1. 전국적으로 본 종실수량과 m$^2$당 수수는 고도의 정상관$(r=0.53^{**})$을 보였다. 2. 품종별 전국 평균수량에서는 400kg/10a 이상의 품종은 조광, Bezostaya, Kitakamikomugi등 이었고 300~400kg/10a의 품종은 원광, 영광, Roussalka, Centurk등 이었으며 300kg/10a 이하의 품종은 Atlas 66, NE 701132이었다. 3. 지역별 수량에서 청주 이북의 4개소 평균수량은 275kg/10a이었고 유성 이남의 4개소 평균수량은 449 kg/10a로 남부지역에서 높았다. 4. 품종 및 재배지역에 따른 종실내 단백질함량과 침전가는 각각 8.9~12.6%, 32~58cc 및 9.0~11.4%, 38~56cc의 범위에 있었고 일반적으로 북부 재배지역에서 단백질 함량 및 침전가가 높았다. 5. 종실내 단백질 함량과 침전가는 고도의 정의 상관$(r=0.66^{**})$이 있었고 종실수량과 단백질 함량 및 침전가 간에는 각각 $-0.49^{**}$ 및 $0.39^{**}$의 부상관이 있었다. 6. 비침전가는 경질 소맥인 Centurk 및 NE 701132 품종에서 높은 반면 조광, Roussalka등의 연질 품종계열들에서는 낮은 경향을 보여 비침전가는 단백질의 질의 평가와 경연질 소맥분류의 좋은 지표가 되었다. 7. 비침전가에 의한 경연질 소맥의 분류기준은 비침전가 4이하는 연질소맥으로, 5이상은 경질소맥으로 그리고 4~5는 중간질 소맥으로 볼 수 있었다.

• Journal of Animal Science and Technology
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• 제59권10호
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• pp.22.1-22.7
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• 2017

Background: Very limited information exists on the ruminal degradation kinetics of nutrients in garlic stalk. The present study aimed to survey the annual yield of garlic stalk in Korea and determine its feed-nutritive value for ruminants. Methods: In Experiment 1, garlic stalk was incubated in situ in the rumen of two Hanwoo steers ($360{\pm}15kg$ body weight) and removed after 12, 24, or 48 h to determine the ruminal degradation kinetics of DM and NDF. Rice straw was also included for comparison. In Experiment 2, In Experiment 2, six male Corriedale sheep were randomized to two dietary treatments to determine the apparent digestibility of nutrients in garlic stalk. Diets included a control ration without garlic stalk (60% concentrate mix +40% ryegrass) or a treatment ration (70% control diet +30% garlic stalk). Results: The Korean national yield of garlic stalk (sun-dried basis) in 2016 was estimated to be 31,910 tons, with the southern coastal regions producing the highest quantity. Compared with rice straw, garlic stalk had lower NDF, higher ADF, and greater effective degradabilities of DM and NDF, resulting in a greater TDN value (56.3%), which was higher than that obtained for rice straw (43.7%). Conclusion: These results provide basic information on the ruminal DM and NDF degradation kinetics of garlic stalk, which would be helpful for the efficient utilization of this by-product in ruminant diets

• 한국작물학회지
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• 제47권3호
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• pp.254-258
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• 2002

앙식미 쌀생산을 위한 기초 정보를 얻고자 조생종인 대진벼, 중생종인 서진벼, 중만생종인 추청벼를 공시하여 농가포장 조건에서 수확시기에 따른 수량과 품질특성을 검토한 결과는 다음과 같다. 1. 백미의 단백질 함량은 대진벼, 서진벼, 추청벼 모두 수확시기가 출수후 40일에서 70일로 늦어짐에 따라 유의하게 증가하는 경향이었다. 2. 식미계에 의한 식미치는 대진벼, 서진벼, 추청벼 모두 출수후 40일에 수확시 유의하게 높았고 출수후 70일로 늦어짐에 따라 낮아지는 경향이었다. 3. 수량과 식미를 함께 고려한 수확적기는 대진벼는 출수후 40-50일, 서진벼와 추청벼는 출수후 40-60일이나 앙식미를 위하여는 3품종 모두 출수후 40-50일에 수확하여야 할 것으로 판단되었다. 4. 식미를 좋게 하는 등숙적산온도는 대진벼와 서진벼는 120$0^{\circ}C$, 추청벼는 110$0^{\circ}C$ 정도일 것으로 추정되었다. 5. 식미치는 백미의 단백질함량과는 매우 유의하고도 직선적인 부의 상관(-0.94$^{**}$ )을 나타내었고 아밀로스함량과는 매우 유의한 정상관(0.66$^{**}$ )을 나타내었다. 6. 식미치는 적산등숙온도와 매우 유의하도고 직선적인 부의 상관(-0.79$^{**}$ )을 나타내어 등숙기간중 적산온도가 낮을수록 식미치가 높았다