• Elastomers and Composites
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• 제54권1호
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• pp.54-60
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• 2019

The rapid development of the automobile industry is an important factor that led to the dramatic development of synthetic rubber. The tread part of tire that comes in direct contact with the road surface is related to the service life of the tire. Rubber compounds used in tire treads are often blended with SBR (styrene-butadiene rubber) and BR (butadiene rubber) to satisfy physical property requirements. However, when two or more kinds of rubber are blended, phase separation and silica dispersion problems may occur due to non-uniform mixing of the rubber. Therefore, in this study, we synthesized an SBR copolymer with the same composition as that of a typical SBR/BR blend compound by controlling butadiene content during ESBR (emulsion styrene-butadiene rubber) synthesis. Subsequently, silica filled compounds were manufactured using the synthesized ESBR, and their mechanical properties, dynamic viscoelasticity, and crosslinking density were compared with those of the SBR/BR blended compound. When the content of butadiene was increased in the silica filled compound, the cure rate accelerated due to an increased number of allylic positions, which typically exhibit higher reactivity. However, the T-2 compound with increased butadiene content by synthesis less likely to show an increase in crosslink density due to poor silica dispersion. In addition, the T-3 compound containing high cis BR content showed high crosslink density due to its monosulfide crosslinking structure. Because of the phase separation, SBR/BR blend compounds were easily broken and showed similar $M_{100%}$ and $M_{300%}$ values as those of other compounds despite their high crosslink density. However, the developed blend showed excellent abrasion resistance due to the high cis-1,4 butadiene content and low rolling resistance due to the high crosslink density.

• 한국식품영양과학회지
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• 제31권1호
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• pp.57-63
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• 2002

배(Pyrus pyrifolia cv. Niitaka) 과실의 검역해충 사멸을 위하여 methyl bromide (MeBr) 훈증의 대체방안을 연구할 목적으로 감마선 조사의 적용가능성을 검토하였다. 배 과실에서 검역대상 해충으로 점박이응애(Tetranychus urticae Koch)와 사과응애(Panonychus ulmi Koch)가 동정되었다. 이들 해충들은 MeBr 훈증에 의해 처리 1일 후 완전 박멸되었으나, 감마선 처리에 의해서는 지효성을 보이면서 조사선량에 비례하여 사충률이 증가되었다. 과실의 호흡량은 조사선량의 증가와 MeBr 훈증에 의해 증가되었다. 과실의 과피 흑변과 과심 장해는 MeBr 처리에 의해 크게 촉진되었으며, 감마선 처리에서도 선량에 비례하여 촉진되었다. 과육경도와 표면색도는 MeBr의 영향 보다는 2 KGy 이상의 감마선 조사에 의해 과육의 연화와 표면색도의 변화가 나타났다. 적정산도는 3 kGy 조사에 의해 다소 낮았으며, 아세트알데히드 함량은 처리조건의 영향을 받지 않았으나, 에탄올 함량은 3 kGy 조사에 의해 증가되었다. 관능적 품질특성은 1 kGy 이상의 감마선 조사에 의해 유의적으로 저하되었다.

• Elastomers and Composites
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• 제59권1호
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• pp.8-16
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• 2024

As regulations on greenhouse gas emission have strengthened globally, the demand for improved fuel efficiency in automobiles continues to rise. In response, the tire industry is actively conducting research to improve fuel efficiency by enhancing tire performance. In this study, silica-filled epoxidized natural rubber (ENR)/butadiene rubber (BR) blend compounds were manufactured according to ENR types and silica contents, and their physical properties and vulcanizate structure were evaluated. ENR-50, which has a higher epoxide content than ENR-25, exhibited stronger filler-rubber interaction, resulting in superior abrasion resistance. In addition, because of its high glass transition temperature (T_g), the wet grip performance of ENR-50 improved, even though the rolling resistance increased. Increasing the amount of silica had little effect on the abrasion resistance due to the increase in filler-rubber interaction and decrease in toughness. In addition, ENR-50 exhibited better wet grip performance; however, the rolling resistance increased. The results indicated that truck bus radial (TBR) tire tread compounds can be designed by applying ENR-50 to improve wear resistance and wet grip performance. In addition, by applying ENR-25 and reducing the silica contents improve fuel efficiency.

• 한국콘텐츠학회논문지
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• 제6권1호
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• pp.160-169
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• 2006

본 논문은 바이트코드(bytecode) 수준에서 프로그램 분석과 최적화를 위한 구조를 서술한다. 바이트코드 수준에서 분석을 수행하기 위해서는 우선 제어 흐름 그래프(CFG : Control Flow Graph)를 생성해야 한다. 바이트코드의 특성 때문에 기존의 제어 흐름 분석 기술을 바이트코드에 적합하게 확장해야 한다. CFG를 작성하기 위해 기본 블록을 생성하고 기본 블록간의 관계를 이용하여 최적화 과정에서 사용되는 각종 정보를 생성한다. 생성된 CFG는 자바 바이트코드의 이해와 유지보수를 위해 테스트되고, 데이터 흐름 분석과 의존성 분석과 같은 다른 분석을 위해서 사용된다. 본 논문에서는 바이트코드 수준의 제어 흐름 분석을 위해 CTOC(Classes To Optimized Classes)의 CTOC-BR(CTOC-Bytecode tRanslator)을 구현한다. CTOC는 자바 바이트코드의 최적화와 분석을 위해 현재 개발 중인 프레임 워크의 이름이고, CTOC에서 CTOC-BR은 스택 기반인 바이트코드의 최적화와 분석을 쉽게 하기 위해 트리 형태로 변환을 수행하는 도구이다.

• Elastomers and Composites
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• 제35권1호
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• pp.38-45
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• 2000

NR, SBR, BR 둥 3가지 고무로 이루어진 가류물에서 고무 조성비가 노화방지제의 이동 거동에 미치는 영향에 대해 연구하였다. 3가지 고무 중 2가지의 함량은 동일하게 하였고 나머지 하나만 다르게 하였다. IPPD와 HPPD를 오존노화방지제로 사용하였다. 실험은 $60^{\circ}C$에서 21일간 방치하는 것과 옥외에서 4개월간 방치하는 것으로 진행하였다. 노화방지제의 이동 속도는 고무 조성비가 NR/SBR/BR = 1/1/0.2에서 1/1/1로 증가함에 따라 증가하다가 1/1/1에서 최대를 나타내 후 다시 감소하였다. 3가지 고무로 이루어진 가류물에서 고무 조성비에 따른 노화방지제의 이동 거동의 변화는 고무와 노화방지제 간의 친화력, 고무에 대한 노화방지제의 융해도, 그리고 이질 고무간에 형성된 경계면 등으로 설명할 수 있었다.

• 미생물학회지
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• 제39권3호
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• pp.155-160
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• 2003

Streptomyces viridochromogenes 야생형과 기중균사 형성 변이주들의 지질과 지방산의 조성을 배양온도와 배양시간에 따라 조사하였다. Triacylglycerol은 기중균사가 형성되는 경우에만 감소되어 기중균사 형성과 연관되어 있음을 나타내었다. 인지질의 경우에는 배양조건에 따른 특이적 변화를 볼 수 없었으나, 기중균사 형성능이 상실된 변이주 BR2가 $20^{\circ}C$에서 배양되었을 매 phosphatidylethanolamine 조성이 특이하게 높게 나타났다. 그리고 변이주 BR2는$20^{\circ}C$및 $30^{\circ}C$ 배양 시 다양한 $R_{f}$ 간의 동정되지 않은 아미노지질들을 함유하였다. 모든 균주에서 아미노지질의 일종인 ornithinolipid는 배양시간이 경과되면서 증가되는 경향을 나타내었다. 지방산조성은 온도에 민감하여 배양온도가 높을수록 불포화지방산 함량이 낮아졌다. 기중균사 형성은 직쇄형 포화지방산의 함량 감소를 수반하였으며, 기중균사 생성능이 우수한 변이주 M13은 배양초기의 직쇄형 포화지방산 함량이 가장 높았다. 변이주 BR2는 iso형 홀수탄소 지방산의 함량이 특이적으로 높았다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.213-213
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• 2022

Pre-harvest sprouting(PHS) refers to germinating seeds in the mother plant before harvesting under low dormancy and humid climate, deteriorating grain quality, and rice yield. Rice varieties with floury endosperm(RFE) have been developed to boost domestic rice consumption by invigorating the processed rice industry, reducing milling and environmental cost. However, the PHS tolerance of RFE is relatively low in the rice varieties with transparent endosperm(RTE) since they soak moisture rapidly due to soft endosperm. In this study, Baromi2(BR2), floury endosperm, and Jomyeong1(JM1), PHS tolerance donor, were crossed to improve PHS tolerance. Major agronomic traits and PHS tolerance test of ten F₇(BR2/JM1) lines were conducted in NICS, 2022. The evaluations of PHS were carried out according to the method of RDA(2012) with slight modifications. Briefly, three panicles were treated and incubated 25℃ in a growth chamber 35 days after the heading date. Ten PHS tolerance promising lines demonstrated floury endosperm. The heading date of BR2 and JM1 was 7/27 and 8/5, respectively. The heading date of promising lines was 7/23~8/10. The PHS rate of BR2 and JM1 exhibited 56.3% and 10.7%, respectively. However, the PHS rate often promising lines demonstrated 2.4%~52.4%, 3 lines significantly lower than BR2. Further studies such as ABA contents are necessary to elucidate the mechanism of PHS tolerance in BR2/JM1. These results may contribute to developing elite RFE lines with improved PHS tolerance.

• 한국식품영양과학회지
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• 제18권3호
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• pp.265-272
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• 1989

구황식품중 9종류를 감출감도가 높고 시료의 비파괴 분석이 가능한 방사화 분석법으로 무기질을 정량한 결과는 다음과 같다. 1. 부추에는 K 7099.1mg%, Cu 104.84ppm, Mo 45.45ppm, Br 40.40ppm으로 다른 식품에 비해 많은 함량을 갖고 있었다. 2. 개비름은 Zn 71.06ppm, Co 2.52ppm, La 1.4ppm 등 조혈 필수원소등을 많이 함유하였다. 3. 쑥은 Na, K, Fe, Cu, Co, Zn, Br등 대부분의 무기질이 많이 함유되어 있는 영양학적으로 우수한 식품이라 볼 수 있다. 4. 본 재료들의 K와 Na의 함량비는 부추가 796 : 1로 가장 크며 쑥, 마늘이 147 : 1, 118 : 1이고 그 이외에는 12 : $1{\sim}53$ : 1이다. 5. 부추 개비름 쑥에는 Fe와 더불어 Cu, Co가 많이 함유되어 있다. 6. 생강에는 Hg가 0.14ppm으로 다른 식품보다 $5{\sim}6$배 많았으며 Sc도 25ppb 함유하고 있다. 7. 식품속에서 극미량 존재하는 Au, Sm, Br, La, Sc등도 분석가능 하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제24권4호
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• pp.517-524
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• 2011

The effect on sow milk of variable levels of cassava in lactating sow diets was analyzed in an attempt to explain the beneficial effects reported by producers of including cassava as a basal feed. Twenty crossbred lactating sows were randomly assigned to five dietary treatments. The treatments were: i) broken rice (BR) as the basal feed (BR100), ii) 50% of BR replaced with cassava chip meal (CCM) (CM50), iii) 75% of BR replaced with CCM (CM75), iv) CCM as the basal feed (CM100), and v) dried boiled cassava chips (CCB) as the basal feed (CB100). The hydrocyanide (HCN) content of CCB was reduced to be intermediate between HCN in the no cassava (BR100) and the 50% cassava (CB50) diets. Hydrocyanide was 0.54, 3.24, 4.41, 5.43 and 1.77 ppm in the BR100, CM50, CM75, CM100 and CB100 diets, respectively. Increasing cassava did not affect feed intake (p>0.05), but increased HCN intake (p<0.01). Milk composition was analyzed for protein, fat, lactose, solids not fat (SNF) and total solids (TS). Milk quality was analyzed for total microbes, coliform bacteria, thiocyanate ($SCN^-$), lactoperoxidase (LPO), and glutathione peroxidase (GPx) activity. At farrowing, sow milk composition was not affected by experimental diets (p>0.05), but milk $SCN^-$ increased as the intake of HCN increased in sows diets (p<0.01), $r^2$ = 0.96. At mid-lactation (day 14), milk composition was not affected (p>0.05). The milk quality levels of $SCN^-$ were 9.4, 10.3, 10.5, 11.6 and 9.1 ppm for the BR100, CM50, CM75, CM100 and CB100 diets, respectively (p = 0.01). The LPO contents were 16.41, 42.13, 51.42, 53.94 and 22.81 unit/L, respectively (p = 0.03). There was no GPx activity found in sow milk. When BR was replaced with cassava meal, total microbes and coliforms were reduced 78% and 87%, respectively, by the influences of HCN. The reported beneficial effects of cassava chip meal as a basal feed in lactating sow diets is manifested by improved performance of suckling pigs. This is due to beneficial, non-toxic levels of HCN in the diets. Besides passing HCN to suckling pigs in the form of $SCN^-$, sow milk may also benefit suckling pigs with the observed (day 14) increase in lactoperoxidase content and reduction in coliform bacteria.

• Asian-Australasian Journal of Animal Sciences
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• 제8권4호
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• pp.329-335
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• 1995

Seven varieties of rice were cultivated in the field of BLRI of which three were native (Maloti, Nizershail and Chandrashail) and four were improved ($BR_3$, $BR_{11}$, Pasam and Mala). Yields of straw and grain were recorded and the chemical composition of straw was determined. Both the grain (p < 0.05) and straw (p > 0.05) yields were higher in the improved than the native varities. Relationships of straw dry matter yield with the hights of rice plants, tiller numbers, levels of N fertilizer and lengths of stover were found to be statistically insignificant. No significant differences were observed among the varieties in respect of NDF, cell soluble, cellulose and hemicellulose contents. However, modified acid detergent fibre and insoluble ash content were significantly (p < 0.05) higher in the local varieties. Except $BR_3$, the estimated ME content of straw was higher in the improved than the native varieties. In respect of yield, chemical composition and energy content improved straws were better and Pasam was the best.