• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.262-266
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• 2018

Phytochemicals have been considered as alternatives for synthetic fungicides because of their biodegradability and low toxicity. In this study, we found that the methanolic extract of Corydalis ternata suppressed the development of plant diseases caused by Puccinia triticina and Colletotrichum coccodes. As the antifungal substance, three isoquinoline alkaloids (dehydrocorydaline, stylopine, and corydaline) were isolated from C. ternata. These active compounds also exhibited in vivo antifungal activity against P. triticina and C. coccodes. Taken together, our results suggest that C. ternata and its active compounds can be used to control plant diseases.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.859-862
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• 2003

Well-aligned multiwall carbon nanotubes (MWCNTs) were prepared at low temperature of 400 $^{\circ}C$ by utilizing a radio frequency plasma-enhanced chemical vapor deposition (rf-PECVD) system. The MWCNTs were treated by an external rf plasma source and an ultra-violet laser in order to modify structural defect of carbon nanotube and to ablate possible contamination on carbon nanotube surface. Structural properties of carbon nanotubes were investigated by using a scanning electron microscopy (SEM), Raman spectroscopy, Fourier transformer Infrared spectroscopy (FTIR) and transmission electron microscope (TEM). In addition, the emission properties of the MWNTs were measured for the application of field emission display (FED) in near future. Various post treatments were found to improve the field emission property of carbon nanotubes.

• Applied Microscopy
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• 제27권2호
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• pp.217-223
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• 1997

New type of ordering along 1110] direction was found In BZT sintered at $1400^{\circ}C$ for 90 hours by using X-ray diffraction analysis and high resolution transmission electron microscopy. The wavelength of the modulated structure was 0.9 nm which is three times larger than the interplanar distance of (110) plane. New type of ordering is considered to be formed as a result of Zn vancacy ordering and new structural model was proposed. The computer simulated electron diffraction and the structural images are in good agreement with those obtained by experiments.

• Carbon letters
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• 제11권3호
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• pp.184-191
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• 2010

Carbon nanotubes are unique tubular structures of nanometer diameter and large length/diameter ratio. The nanotubes may consist of one up to tens and hundreds of concentric shells of carbons with adjacent shells separation of ~0.34 nm. Multiwalled carbon nanotubes were synthesized by arc-discharge technique. MWCNTs were formed at the cathode deposit along with other carbonaceous materials like amorphous carbon, graphite etc. However, to get the best advantage of carbon nanotubes in various advanced applications, these undesired carbonaceous materials to be removed which is a challenging task. In the present study, various techniques were tried out for purifying MWCNTs such as physical filtration, chemical treatment and thermal annealing. SEM, FTIR, TGA and BET techniques were used to characterize the CNTs at various stages. Results shows that suitable chemical treatment followed by thermal annealing under controlled flow of oxygen gives the better route for purification of carbon nanotubes.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2004년도 동계학술연구발표회 논문개요집
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• pp.219-220
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• 2004

Superparamagnetic regions and magnetic anisotropic properties in randomly orientated Co nano dots(NDs) were investigated as a function of dot diameter, spacing, and density. The Co NDs were fabricated by intentionally exposing a laser source on ultra thin film. Various dot sizes are ultimately realized by changing laser power, scan condition, and intial film thickness. Magnetic hysteresis loops, angle-dependent magnetization, and temperature dependence magnetization of the Co NDs were measured with a superconducting quantum interference device. The analysis of magnetization and hysteresis loops was effectively used to determine superparamagnetic regions of the Co NDs. Up to now, the experimentally observed results repeal that room temperature superparamagnetic limit of our Co NDs was about 30 nm in diameter, with the confirmation of high resolution transmission electron microscope.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2004년도 춘계학술발표대회 논문집
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• pp.161-166
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• 2004

In recent years, living space of modern society have vared, and new methods to build have been introduced using new building materials and interior finishing materials as the life level is enhanced. But these kinds of materials release some harmful substances to people. The most of people living in new apartment have headache and dizziness, and feel sick of the stomach, sleepiness, eye stimulus, concentration decrease and allergies. That called 'sick house syndrome'is becoming new society problem. The purpose of this study is to investigate the kinds and various problems of the interior finishing materials and to pursue improvement of living place and pleasant interior surroundings.

• Bulletin of the Korean Chemical Society
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• 제29권4호
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• pp.758-760
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• 2008

Nanoporous AAO (Anodic Aluminum Oxide) membranes have many advantages as a template for variety of magnetic materials. Materials can be embedded into the pores by electrodeposition, sputtering or magnetic-field-assisted infiltration of magnetic nanoparticles. This work focuses on the fabrication of the magnetic structures in the AAO templates by electrodeposition. Our method allows the controlled growth of Co nanostructures within the porous alumina membrane in the form of dots, rods and long wires. The shape of Co nanostructures has been investigated by field emission scanning electron microscope (FESEM). The magnetic hysteresis loops of Co nanostructures were measured using SQUID at 5 K and 300 K. The magnetic properties of the Co nanostructures are proportional to their aspect ratios and can be controlled by changing the aspect ratios.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.346-347
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• 2006

New manufacturing processes, such as thermochemical, mechanochemical and chemical vapor condensation processes have been developed to obtain nanostructured WC/Co materials. Nanoscale size WC/Co composite powders of near 100-150nm can be synthesizes by thermochemical and mechanochemical processes using water soluble precursors. Non-agglomerated and nano sized WC powder can be synthesized by the chemical vapor condensation process using metallorganic precursors as starting materials. In this paper, the scientific and technical issues on synthesis and consolidation of nanostructured WC/Co alloys produced by new chemical processes are introduced.

• 한국재료학회지
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• 제27권6호
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• pp.301-306
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• 2017

The discovery of new luminescent materials for use in light-emitting diodes(LEDs) has been of great interest, since LED-based solid state lighting applications are attracting a lot of attention in the energy saving and environmental fields. Recent research trends have centered on the discovery of new luminescent materials rather than on fine changes in well-known luminescent materials. In a sense, the novelty of our study beyond simple modification or improvement of existing phosphors. A good strategy for the discovery of new fluorescent materials is to introduce activators that are appropriate for conventional inorganic compounds, that have well-defined structures in the crystal structure database, but have not been considered as phosphor hosts. Another strategy is to discover new host compounds with structures that cannot be found in any existing databases. We have pursued these two strategies at the same time using composite search technology with particle swarm optimization(PSO). In this study, using PSO, we have tracked down a search space composed of Sr-Al-Si-O-N and have discovered a new phosphor structure with yellow luminescence; this material is a potential candidate for UV-LED applications.

• 정보관리연구
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• 제27권2호
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• pp.1-32
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• 1996

1990년대에 들어오면서 도서관에 데이터베이스 온라인탐색 및 CD-ROM탐색이 보편화되고 이러한 뉴미디어들은 이용자의 편의성 면에서, 도서관 경영적인 측면에서, 또는 소장공간의 효율적인 측면에서 볼 때 기존의 책자형 자료보다 도입효과가 있을 것으로 기대된다. 그러나 새로운 자료를 도입하거나, 시스템을 설계할 때 비용 대 효과를 객관적으로 평가하여야 하고, 구체적인 평가지침에 근거하여 일관성 있는 장서구성을 하여야 하므로 본 연구에서는 대외경제정책연구원 정보자료실을 모델로 하여 기존문헌, CD-ROM, 온라인탐색을 비교 평가하고자 한다.