• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.293-293
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• 2008

초전도 케이블은 저손실 대용량 전력수송이 가능한 전력케이블로서 대도시의 전력 공급문제를 해결할 수 있는 환경 친화적 신개념의 전력케이블이다. 한전 전력연구원 고창전력시험센터에서는 2006년에 22.9 kV, 100 m, 50 MVA급 초전도케이블 시스템을 설치하여 초전도케이블 실용화를 위한 신뢰성 시험을 실시하고 있다. 전력케이블의 주요한 신뢰성 요인 중의 하나가 절연특성이며 초전도케이블의 절연특성은 운전온도가 액체질소 온도이므로 절연지에 수분이 고화하여 일반적인 전력케이블보다 좋은 절연특성을 보이는 것으로 알려져 있다. 초전도 케이블은 절연지와 액체질소에 의해 절연이 이루어지며 열적, 기계적, 전기적, 환경적 스트레스에 의해 열화가 발생할 수 있다. 절연층에 이러한 스트레스가 누적되면서 void가 발생하게 되고 전계집중 현상에 의해 절연성능이 저하되며 과다한 열화의 발생시 절연파괴가 일어나게 된다. 온 발표에서는 운전온도 66.4 K에서 1.5 $U_0$ (20 kV) 전압의 30일간 연속 인가 시험과 초전도 케이블의 절연열화 가속시험을 통하여 얻은 부분방전 및 정전용량의 변화 등의 절연특성 평가 결과에 대해 논의한다.

• 한국전자현미경학회:학술대회논문집
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• 2005.11a
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• pp.80-84
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• 2005

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2802-2804
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• 2011

• 한국전자현미경학회:학술대회논문집
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• 2004.11a
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• pp.139-144
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• 2004

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.414-417
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• 2005

Single point diamond turning technique for optical crystals is studied in this paper. The main factors which are influential the machined surface quality are discovered and regularities of machining process are drawn. Optical crystals have found more and more important applications in the field of modern optics. Optical crystals are mostly brittle materials of poor machinability. The traditional machining method is polishing which has many shortcomings such as low production efficiency, poor ability to be automatically controlled and edge effect of the workpiece. The purpose of our research is to find the optimal machining conditions for ductile cutting of optical crystals and to apply the SPDT technique to the manufacturing of ultra precision optical components of brittle material(Ge). Many technical challenges are being tried for the large space infrared telescope, which is one of the major objectives of the National Strategic Technology Road Map (NSTRM).

• Proceedings of the Korea Technology Innovation Society Conference
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• 2005.05a
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• pp.306-320
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• 2005

Government-sponsored Research Institutes(GRIs) have made a great contribution to the development of Korea's Science and Technology(S&T). However, recently GRIs are facing the challenge of many problems. For instance, absence of reasonable strategies, insufficient resources and so on. Therefore, many GRIs are being asked for solving their problems with successful strategic management. This paper suggests a strategic management model to solve their problems and to cope with the changing S&T environment. In this paper, The strategic management model for GRIs which was thoroughly considered strategic management process suggested to response the need of their change and to perform their strategic management successfully. As a case of GRIs to apply this model, in this paper, Korea Basic Science Institute(KBSI) that is part of the Korea Research Council of Fundamental Science and Technology(KRCF) was analyzed. As a result of analysis with this model which applied to KBSI, various strategies and alternatives were suggested.

• Journal of Microbiology and Biotechnology
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• v.25 no.4
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• pp.448-451
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• 2015

In a previous study, we isolated octaphlorethol A (OPA) from Ishige foliacea and evaluated its anti-melanogenesis activity in a murine melanoma cell line. However, the whitening effect and toxicity of OPA have not yet been examined in vivo. Therefore, in this study, we investigated the inhibitory effect of OPA on melanin synthesis and tyrosinase activity in an in vivo zebrafish model. More than 90% of subject embryos survived upon exposure to OPA concentrations below $25{\mu}M$, which was not significantly different from the finding in the control group. OPA markedly inhibited melanin synthesis and tyrosinase activity in a concentration-dependent manner.

• Applied Microscopy
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• v.37 no.2
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• pp.111-121
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• 2007

Coefficient of spherical aberration of the objective lens in the KBSI-HVEM was evaluated by diffractogram method. Instrumental resolution was also discussed with this method. In order to improve the accuracy, digital processing and graphical curve fitting for intensity profile of diffractogram were employed. Experimental concerns where the optimal procedure of the measurement con be accomplished for this study were discussed. The spherical aberration coefficient $(C_s)$ was estimated to be $2.628{\pm}0.04\;mm$ from this study, which was almost coincident with the value of the manufacture's suggestion $(C_s=2.65\;mm)$.

• Mass Spectrometry Letters
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• v.13 no.4
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• pp.106-114
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• 2022

A rapid and reliable approach to the identification of microorganisms is a critical requirement for large-scale culturomics analysis. MALDI-TOF MS is a suitable technique that can be a better alternative to conventional biochemical and gene sequencing methods as it is economical both in terms of cost and labor. In this review, the applications of MALDI-TOF MS for the comprehensive identification of microorganisms and bacterial strain typing for culturomics-based approaches for various environmental studies including bioremediation, plant sciences, agriculture and food microbiology have been widely explored. However, the restriction of this technique is attributed to insufficient coverage of the mass spectral database. To improve the applications of this technique for the identification of novel isolates, the spectral database should be updated with the peptide mass fingerprint (PMF) of type strains with not only microbes with clinical relevance but also from various environmental sources. Further, the development of enhanced sample processing methods and new algorithms for automation and de-replication of isolates will increase its application in microbial ecology studies.

• Applied Microscopy
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• v.42 no.1
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• pp.49-52
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• 2012

For TEM study of biological samples or polymers that are contained in organic structure, it is often required that the sample is prepared by using ultramicrotome and stained with proper agents to increase the contrast of organic structure. In this study, we investigated an efficient TEM sample preparation method for ductile heterogeneity material by using ultramicrotomy. Cryo-ultramicrotomy is a suitable method that is capable of rendering sample hardness for various ductile materials. However, it has several factors to consider, such as experimental cost, working time and finding the optimal staining conditions. To satisfy these considerations, we prepared TEM sample by using ultramicrotome without cryofunction, and secured the sample hardness by applying the staining process prior to ultrathin sectioning. The cross-linked polyethylene structure in the sample was stained with the 2% $RuO_4$ solution in a sealed test tube for 24 hours at $4^{\circ}C$. After the sample staining, ultrathin sections of sample were prepared using ultramicrotome. As a result, it was revealed that the difficulties associated with staining of ultrathin sections prepared by low-temperature conditions were improved. In addition, appropriate staining depth of sample could be selected for sectioning process. The quality of TEM sample obtained by using this method was better than that of cryo-ultramicroscopy. Finally, it is expected that our method could be effectively applied in TEM sample preparation for a variety of nano-bio convergence materials.