• Korean Journal of Plant Resources
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• v.32 no.4
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• pp.290-295
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• 2019

This study was carried out to select the optimal condition for prothallus propagation and sporophyte formation of Leptogramma pozoi (Lag.) Ching subsp. mollissima (Fisch. ex Kunze) Nakaike and to provide basic data for mass production system. In the propagation, 300 mg of prothallus were inoculated in different kinds of medium [1/4, 1/2, Murashige and Skoog (MS), Knop], sucrose (0, 1, 2, 3, 4%), and cultured for 8 weeks. Sporophyte formation studies were carried out by inoculating blended prothallus into artificial soils. The soils were mixed with horticultural substrate, peatmoss, perlite, and decomposed granite at different ratios or only with the horticultural substrate. Then the prothallus was cultivated for 12 weeks to figure out the formation and growth of the sporophytes. The growth and development of prothalli were excellent on MS medium. According to medium components, prothallus growth was favorable in all treatments except 0% sucrose treatment and the highest in 2% sucrose. In the experiment of soil mixtures, sporophyte formation was the highest in the horticultural substrate:perlite 2:1 (v:v) and horticultural substrate:decomposed granite 2:1 (v:v) treatment, and the overall growth was good in the horticultural substrate:decomposed granite 2:1 (v:v) mixed soil.

• Journal of Korean Society of Steel Construction
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• v.16 no.4 s.71
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• pp.415-423
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• 2004

To investigate the long-term corrosion resistance of an uncoated weathering steel, an important outdoor constructional steel material, skyward surfaces of the weathering steel and a control steel initially exposed to rural and industrial atmospheres for 9 years were electrochemically tested in neutral artificial rain in terms of electrochemical potentials, impedances, and anodic potentiodynamic polarization curves. Their results were then discussed. A quite passive and stable rust layer to the artificial rain was well formed on the skyward surface of the weathering steel exposed to the industrial and rural atmospheres, and its corrosion rate in the artificial rain was measured to be about a low $3{{\mu}m}/y$. Continuous immersion of all the weathered surfaces in the artificial rain revealed the gradual degradation of the weathered corrosion layers on the steel, resulting in a cathodically controlled corrosion of the substrate steel by the electrochemical measurements. Alloy components of the weathering steel were found to retard the degradation of the weathered corrosion layers on the steel in the artificial rain. For better corrosion evaluation of the weathering steel, more electrochemical measurements of surfaces that have been exposed for more than 9 years to more closely simulated atmospheric waters are needed. These measurements are almost non-destructive and can provide online and in situ information on the corrosion rate, the development of corrosion and the conditions of rust layers on any interested surface and at any exposure time of the steel, so they can be effectively applicable to the corrosion evaluation of steel structures such as bridges, towers, and architectures by forming an electrochemical cell on an interested structural surface and by using a portable electrochemical instrument.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.220-222
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• 2009

적층형 가유전체 구조는 유효유전율과 유효투자율은 주어진 표준형 전송선로의 경우보다 증가하므로 결과적으로 전송선로의 길이를 짧게 할 수 있는 장점이 있다. 따라서 회로의 소형화에 유용하게 사용될 수 있는데, 본 논문에서는 한 예로써 대표적인 무선 회로인 방향성 결합기의 소형화된 회로에 대하여 기술하고 있다. 표준형 회로와 적층형 가유전체 구조를 이용하여 소형화한 방향성 결합기를 2GHz 대역에서 설계하여 실제로 제작하여 측정한 결과를 제시한다. 종래의 표준형 회로와 비교할 때, 동일한 성능을 유지하면서도 회로의 크기가 49.4%만큼 감소한 결과가 소개된다.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.474-476
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• 2012

적층형 임의유전체 기판구조는 유효유전율과 유효투자율이 주어진 표준형 기판구조보다 증가하므로 결과적으로 전송선로의 길이를 줄일 수 있는 장점이 있다. 따라서 회로의 소형화에 유용하게 사용될 수 있다. 본 연구에서는 한 예로써 임의유전체 기판구조를 이용한 초고주파 증폭기의 소형화에 대하여 기술한다. 표준형 기판구조와 임의유전체 기판구조를 이용하여 2GHz 대역에서 무선통신용 초고주파 증폭기를 설계하여 그 결과를 제시한다. 종래의 표준형 기판구조를 이용한 회로와 비교할 때, 동일한 성능을 유지하면서도 회로의 크기가 23%만큼 감소한 설계 결과가 제시된다.

• The Korean Journal of Mycology
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• v.20 no.3
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• pp.273-276
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• 1992

Armillaria mellea mushrooms were cultivated on the sawdust media, Quercus sawdust; rice bran=80:20 in polypropylene bags. The isolate of Armillaria mellea used was ARM69002F collected from a Korean pine plantation in Hongcheon district. The length of time between spawning and fruiting was required for 90 to 100 days. The number of fruiting bodies produced in a bags with a kg substrate were approxinately 31 (range of 18 to 62), and the total fresh weight 158g (61 to 207g), converted to 13 to 15% of fresh weight. The pilei of fruiting bodies were average 4.0 cm (2.5 to 7.6 cm)wide, and their stipes 8.2 cm long and 0.6 cm-thick at the upper part and 1.2 cm at the base.

• Food Science and Preservation
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• v.5 no.1
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• pp.13-21
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• 1998

Korean medicinal herb extracts(KMHE) were applied to the preservation of greenhouse produce in order to prove their effectiveness. KMHE showed remarkable antimicrobial effects against Bacillus cereus, Peudomonas syringae, and Corynebacterium xerosis causing the postharvest decay of greenhouse produce. Among KMHE the extracts of Rheum palmatum L. and Coptis chinensis Franch most obviously inhibited the growth of microorganims causing the Postharvest decay of greenhouse produce, which destroyed to undetectable levels when treated with more than 500ppm of KMHE. The activities of KMHE were stable in the wide spectrum of pH and temperature. Direct visualization of microbial cells by using both transmission electron microscope and scanning electron microscope showed microbial cell membrane the function of which was destroyed by treating with the dilute solutions of KMHE. This change of cellular membrane permeability could be identified in the experiment that O-nitrophenyl-$\beta$-D-galactopyranoside(ONPG), the artificial substrate of $\beta$-galactosidase, was hydrolyzed in the presence of KMHE, indicating that the membrane was perturbed by KMHE.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1253-1254
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• 2015

양면형으로 구성된 가유전체 기판에 마이크로파 대역 전송선로를 설계하여 크기를 약 절반으로 줄이는 방법을 제안한다. 가유전체 기판의 특성에 의하여 표준형 전송선로보다 길이가 현저하게 줄어드는 효과에 더하여, 가유전체 기판을 양면형으로 구성함으로서 다시 물리적 크기가 약 절반으로 줄어드는 효과가 보인다. 양면 전송선로는 신호선 비어홀(via-hole)에 의하여 연결되어 상하 전송선로 간에 전달특성이 양호함이 제시된다.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.300-302
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• 2009

적층형 가유전체 구조는 유효유전율과 유효투자율은 주어진 표준형 전송선로의 경우보다 증가하므로 결과적으로 전송선로의 길이를 짧게 할 수 있는 장점이 있다. 따라서 회로의 소형화에 유용하게 사용될 수 있는데, 본 논문에서는 한 예로써 대표적인 무선 회로인 윌킨슨 전력분배기의 소형화된 회로에 대하여 기술하고 있다. 표준형 회로와 적층형 가유전체 구조를 이용하여 소형화한 윌킨슨 전력분배기를 2GHz 대역에서 설계하여 실제로 제작하여 측정한 결과를 제시한다. 종래의 표준형 회로와 비교할 때, 동일한 성능을 유지하면서도 회로의 크기가 32%만큼 감소한 결과가 소개된다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.494-497
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• 2003

We report the dark spots in organic light emitting diodes by using a near-field scanning microwave microscope. Devices structure was glass / indium-tin-oxide(ITO) / copper-pthalocyiane(Cu-Pc) / tris-(8-hydroquinoline)aluminum(Alq3) / aluminum(Al). We made artificial dark spots by using a etching technique on a ITO substrate. Near-field scanning microwave microscope images and reflective coefficient of dark spots were measured and compared by the change of various applied voltage changes 0-15V.

• Journal of Practical Agriculture & Fisheries Research
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• v.8 no.1
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• pp.63-70
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• 2006

Truffles are cultivated by growing seedlings of compatible tree species in pasteurized substrate amended with truffle spores, maintaining the inoculated seedlings in the greenhouse until the mycorrhizal relationship is established and certified, planting the infected seedlings onto appropriate and properly prepared sites, and managing the resulting truffieres (truffle orchards) to maintain the truffle infections and encourage truffle fruiting. Questions remain to be addressed at each step of the process in developing best management practices for truffle cultivation.