• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.2
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• pp.146-154
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• 2021

This study was conducted to determine the degree of reduction in the yield of sweetpotato subjected to different shading treatments according to the growing season of the typical viscous sweetpotato 'Hogammi' and the powdery sweetpotato 'Jinyulmi'. Shading was provided using commercially available shading nets (55% and 75% shading level), and the treatments were applied at the following stages of storage root growth: SFS: the storage root formation stage (planting-50^th day), SSS: the storage root swelling stage (50-90^th day), and SAS: the storage root actively swelling Stage (90-120^th day). The growth characteristics according to shading treatments during each growth period, the number of tubers obtained at harvest, and sugar contents were investigated. For both assessed cultivars, there was no significant difference between the control group and the 55% shading treated group with respect to the maximum quantum yield (Fv/Fm) of photosystem II under different shading treatments, whereas the 75% shading group showed slightly higher values than the control group. In both cultivars, the contents of chlorophyll a and b tended to increase in plants subjected to shading treatments compared with the control plants, particularly that of chlorophyll b. Compared with the control group, the chlorophyll b content of 'Hogammi' subjected to 55% and 75% shading increased by 47% and 41%, respectively, whereas that of 'Jinyulmi' increased by 39% and 34%, respectively. We also detected reductions in the dry weights of the above- and belowground parts of the two varieties in response to shading compared with the control, with the reduction in the dry weight of belowground parts being significant. Furthermore, in both varieties, the T/R rate tended to increase in response to shading treatment. Owing to the lack of sunlight, both cultivars tended to suppress the formation and enlargement of tuber roots. Consequently, post-harvest yield analysis revealed that under shading treatments, both cultivars were characterized by poor tuber root growth according to growing season, with the yield of 'Hogammi' showing a greater reduction compared with that of 'Jinyulmi'. In addition, we found that the higher shading level also significantly reduced yields. Compared with the storage root formation and storage root actively swelling stages, shading treatments during the storage root swelling stage significantly affected yield reduction in both varieties.

• 핵융합뉴스레터
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• s.47
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• pp.16-17
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• 2010

선선한 가을바람이 조금씩 불어오는 9월의 어느 날, ITER 한국사업단 토카막기술부 진공 내벽기술팀원들이 한자리에 모였다. 장난기 가득한 미소를 띠며 앉아 있는 이들은 요즘 ITER 프로젝트로 눈코 뜰새 없이 바쁜 나날을 보내고 있는 ITER 진공 내벽기술팀. 한창 바쁜 요즘이지만 긴장과 피로에 지친 모습은 이들에게서 찾아보기 힘들다. 대신 서로에 대한 관심과 애정으로 가득한 모습을 볼 수 있었다.

• Clean Technology
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• v.16 no.3
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• pp.220-228
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• 2010

Four Keggin-type heteropolyacids, $H_nXM_{12}O_{40}$(X = P and Si, M = W and Mo) that were substituted with heteroatom and polyatom were applied to the dehydration reaction of fructose to 5-hydroxymethylfurfural (HMF). The results showed that the acid became stronger when the heteroatom and polyatom were substituted with P and W than the cases of Si and Mo, respectively. However, the amount of acidic sites increased with the decrease in the acid strength, resulting in the change of the catalytic activity of heteropolyacids in the dehydration reaction. The experimental results revealed that four different heteropolyacids produced similar amounts of HMF via the dehydration reaction of fructose due to the counterbalancing effect between the amount of active sites, which is related to the catalytic activity of heteropolyacids, and the softness of polyanion. In addition, it was observed that the prepared heteropolyacids showed good structural stability after heat treatment at $200^{\circ}C$.

• The Science & Technology
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• v.20 no.1 s.212
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• pp.12-13
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• 1987

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.109-109
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• 2017

전 세계적으로 기후변화, 인구증가, 도시화에 따른 물, 에너지, 식량 등 필수 자원의 수요량 증가로 인한 수급 불균형으로 글로벌 자원안보 위기가 대두되고 있다. 특히, 국내의 경우 경제성장로 인한 중산층 증가와 도시 인구 팽창에 따른 물, 에너지, 식량 등 필수 자원에 대한 수요 증가로 인해 유한한 자원에 대한 대응책이 시급한 실정이다. 또한 국내 자원의 대외 의존성이 높아 국제 자원 시장에 크게 영향을 받기 때문에 물-에너지-식량의 연계를 통한 자립적 자원확보가 필요하다. 국내에서도 수자원 자체만의 기존 기술 한계를 극복하기 위한 물-에너지, 물-식량 연계신기술 개발과 지속가능한 활용방안이 필요한 실정으로 현재 미국, 일본, 유럽 등 주요 선진국을 중심으로 물관리와 연계한 에너지의 효율화 및 수자원이 갖는 에너지의 회수와 적극적 활용이 추진되고 있다. 이를 반영하여, 국내의 경우 독립적으로 구분되는 이수, 치수, 물순환 건전화 등 주요 물관리 이슈에 대하여 에너지, 식량 분야를 연계한 통합적이고 효율적인 지속가능 방안제시가 필요하다. 이를 위해 자원안보의 선제적 대응을 위한 구체적이고 실질적인 물-에너지-식량의 연계 기술이 필요하며, 국내 실정에 적합한 기술의 도입이 필요하다. 즉 (1) WEF 데이터공유 및 범정부적 의사결정을 위한 다부처 협업체계 구축을 위한 Bigdata기반 부처간 데이터베이스 구축 및 공유 (2) 기후변화 적응 자원연계 솔루션 개발 및 넥서스 영향평가 툴 개발을 위한 자원 효율성 증대를 위한 연계 기술 고도화 (3) 국내(미래넥서스시티 versus 지자체자립형넥서스마을), 해외 on-demand형의 미래자원관리 패키지기술 실증을 위한 국내외 Testbed구축 및 운영 (4) 기술의 실현을 위한 제도, 정책의 개선 및 국민 공감대 형성을 위한 WEF 넥서스 거버넌스 수립 및 개선으로 구분할 수 있다. 이를 통해, 물-에너지-식량 분야 상호 연계를 통한 분야별 "생산-가공-유통처리" 효율 30% 개선, 20C SOC 시설산업기반에서 21C 사회 인프라 국민 서비스 산업으로 전환을 통한 국가 신산업기반 구축, 4차 산업혁명의 Data Technology 분야에서 세계 최초의 공공기반 WEF 연계 패키지 기술 개발 들이 가능할 것으로 판단된다.

• Nuclear Engineering and Technology
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• v.17 no.3
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• pp.211-215
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• 1985

The effects of temperature and strain rate on the I-SCC behaviors of Zircaloy-4 were investigated by constant load test at 30$0^{\circ}C$ and constant elongation rate test at 300, 350 and 40$0^{\circ}C$ in 3.34mg $I_2$/㎤. The results showed that I-SCC susceptibility increased as the strain rate decreased or the temperature increased. The empirical relation between the stress and the time to failure at 30$0^{\circ}C$ was given by 1/ $t_{f}$∝exp (0.3$\sigma$/$\sigma$$_{UTS}$-31.5) When the I-SCC susceptibility was expressed by the ratio of fracture energy in iodine atmosphere to that in the inert atmosphere, severe I-SCC susceptibility was found near 7.6$\times$10$^{-6}$ sec at 30$0^{\circ}C$ and the maximum point of I-SCC susceptibility tended to shift to the higher strain rate with increasing the temperature. The quasi-cleavage fracture was observed in I-SCC fracture surface. From these results, it was certain that the film repture step was involved as an important process in the I-SCC mechanism of Zircaloy-4.4.

• Radioisotope journal
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• v.2 no.1
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• pp.15-16
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• 1987

• Nuclear industry
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• v.6 no.1 s.35
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• pp.24-25
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• 1986

• The Science & Technology
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• v.23 no.1 s.248
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• pp.24-25
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• 1990

• The Science & Technology
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• v.19 no.2 s.201
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• pp.48-49
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• 1986