• Journal of the Korean Vacuum Society
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• v.5 no.2
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• pp.133-138
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• 1996

Epitaxial cubic silicon carbide films have been deposited on carbonized Si(001) substrates using the single precursor 1, 3-disilabutane in the temperature range 900-$1000^{\circ}C$ under high vacuum conditions. The films grown were characterized by in situ RHEED, XPS, XRD, x-ray pole figure, SEM, and TEM. The results show that epitaxial cubic SiC films with smooth morphology and good crystallinity were formed in this temperature range. The single precursor 1, 3-disilabutane has been found suitable for the epitaxial growth of cubic SiC on Si(001) substrates.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.368.2-368.2
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• 2014

$SnO_2$을 이용한 반도체는 기체 센서, 트랜지스터, 태양전지와 같은 여러 분야에 적용 가능하기 때문에 많은 각광을 받고 있다. $SnO_2$을 이용한 반도체 소자는 높은 화학적 안정성과 독특한 물리 화학적 특성을 지니고 있을 뿐만 아니라 부피에 대한 높은 표면적 비율을 가지고 있다. 우수한 $SnO_2$나노구조를 얻기 위해서 전자관 박막증착, 졸겔법, 물리적 증기증착, 열증착과 같은 다양한 방법들이 사용되었다. 다양한 합성 방법들 중에서 전기화학 증착법은 높은 성장율, 대면적 공정, 낮은 가격과 같은 장점을 가지고 있어 많은 연구가 진행되었지만, $SnO_2$ 구조의 성장조건에 따른 체계적인 연구는 진행되지 않았다. 본 연구는 indium-tin-oxide (ITO)로 코팅된 유리 기판 위에 전기화학 증착법을 사용하여 다양한 성장 조건에 따라 성장된 $SnO_2$나노구조들의 물리적 특성들을 관찰하였다. ITO 유리 기판 위에 성장된 $SnO_2$나노구조는 음극의 전구체와 전류의 상호작용에 의해 생성되는 산소 분자의 환원에 의해 형성된다. $SnO_2$나노구조의 모양은 전기화학 증착의 성장 환경에 따라 달라진다. $SnO_2$나노구조를 관찰하기 위해 시간에 따른 전압-전류, X-ray광전자분광법, 주사형전자현미경, X-ray회절분석법을 사용하여 측정하였다. ITO 유리 기판 위에 성장한 $SnO_2$ 소자에 서로 다른 인가 전압을 가해 주었을 때에 따른 전류밀도를 측정하였다. 일정한 인가전압에서 $SnO_2$나노구조의 X-ray광전자분광법 측정 을 통해 화학적 결합과 X-ray회절분석법 통한 $SnO_2$ 성장 방향을 관찰하였다. 주사형전자현미경 측정을 통하여 $SnO_2$의 표면을 관찰하였다

• Electrical & Electronic Materials
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• v.9 no.3
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• pp.270-276
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• 1996

As methane concentration was varied, the textures of diamond films deposited on Si(100)substrate were observed by XRD,SEM and Raman spectroscope. As a result, $O_{2}$ plasma etching has been useful to observe microscopic structure of diamond films by SEM. The cross section of diamond films deposited on Si(100)substrate with 4% concentration of methane to hydrogen was a polycrystal like a pillar. The diamond crystal like a pillar has been oriented to (110)surface and the high quality diamond film with FWHM of Raman spectra being 3.8 $cm^{-1}$ / has been grown. As time goes by deposition time, the preferred orientation increases

• Research in Plant Disease
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• v.14 no.3
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• pp.214-218
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• 2008

Coleosporium neocacaliae, a needle rust fungus, was described and illustrated for the first time on the needles of Pinus koraiensis (Korean pine) in Korea. Detailed descriptions of the species were verified based on symptoms and signs, and light and scanning electron microscopic observations on aecia, aeciospores and peridial cells. The present needle rust fungus was apparently different from C. eupatorii, a solely recorded Coleosporium species on P. Koraiensis in Korea until this time, in having comparatively large sized aeciospores as $20-39{\times}14-27\;{\mu}m$ than those of latter species (size of aeciospores $15-27{\times}10-20\;{\mu}m$). Verrucose surface structure of aeciospores in light microscopy was revealed to be annulated with three to four rings and root-like base in scanning electron microscopy. Aecial stage of C. neocacaliae were formed on the middle days of April to the early days of June and collected around the central parts of Korean peninsula, including high mountains of about 1,000 m above sea level.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.47-47
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• 2018

단일벽 탄소나노튜브 (Single-walled carbon nanotubes, SWNTs)는 우수한 물리적 화학적 특성을 갖고 있어 나노전자소자, 투명전도막, 에너지소자, 센서 등 다양한 분야로의 응용이 기대되고 있다. 열화학기상증착(Thermal chemical vapor deposition, TCVD)법은 SWNTs의 합성 공정이 간단하고 공정변수의 제어가 용이하다는 장점이 있어 SWNT 합성 연구에 가장 널리 사용되어 왔다. 일반적으로 금속 촉매의 박막이 증착된 합성 기판은 온도가 가장 높고 비교적 균일성이 보장되는 TCVD 반응기의 중심부에 위치시키고 공정변수를 변화해가며 연구를 진행해 왔다. 본 실험실에서는 수평형 반응기 전역에 합성 기판을 설치하여 SWNTs를 합성한 결과, 반응기의 중심보다 뒤의 영역에서 SWNTs의 합성 수율이 상당히 증가하는 것을 초기실험을 통해 확인하였다. 본 연구에서는 SWNTs 합성 시 가스 유량과 합성 온도를 변화시켰을 때 기판 위치에 따른 SWNTs의 수율 및 물성변화를 구체적으로 조사하였다. 합성가스와 촉매로는 메탄가스와 철 박막을 사용하였으며, 합성 수율의 변화는 고분해능 주사전자현미경을 이용하여 관찰하였다. 그리고 합성된 SWNTs의 형태 및 결정성은 라만분광법과 원자간힘현미경을 이용하여 평가하였다. 결과적으로, 진행하였던 모든 합성 조건에서 반응기 중심보다 뒤의 영역에서 더 고수율의 SWNTs가 합성되었으며, 최적 합성 조건의 SWNTs 면밀도는 99% 이상이었다. 본 연구의 결과는 CVD 공정을 이용하는 다양한 저차원 나노 소재의 합성에도 적용될 수 있을 것으로 사료되며, 추후 이에 대한 연구가 필요하다.

• Applied Microscopy
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• v.10 no.1_2
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• pp.41-51
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• 1980

Scanning electron microscopic observation of the oviductal epithelium was carried out on the virgin white Wistar rat during normal sexual cycle, and obtained the results as follows; Rat oviductal epithelium during the normal sexual cycle generally consisted of two types of cells: ciliated and non-ciliated cell. The ciliated cells had cilia which was measured $0.2{\mu}$ in width and $3-5{\mu}$ in length. According to the length of microvilli and the distribution in each segment, the non-ciliated cell was further subdivided into four types of cells; NC-I, NC-II, NC-III, and NC-IV. The morphologic characteristics of each type of cells were also ascertained by SEM observations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.11
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• pp.1705-1712
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• 2001

Mechanical component has striation with constant width and SEM can estimate fracture type and loading condition. SEM has benefit to fatigue fracture analysis but striation can be observed according to the kind of material and range of crack growth rate and can't. In this case, it needs AFM that can measure 3-dimensional surface profile with resolution of atomic size. In this study. to find fracture reason of torsion-mounted blade in nuclear plant, we estimate the relation between stress intensity factor range and root mean square roughness in 12% Cr steel by AFM and predict in-service loading condition of turbine blade. failure analysis is performed by finite element method and Goodman diagram on torsion-mounted blade.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.10
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• pp.61-68
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• 2001

Turbine blade in nuclear plant is subject to cyclic bending fatigue by high steam pressure. Especially, fatigue fracture is caused by low stress below yielding stress. Photograph by SEM doesn't have striation but photograph by AFM has striation on the fatigue fractured surface of 12% Cr steel used in turbine blade. Surface roughness $R_q$ has the linear relation with respect to stress intensity factor range ΔK and is increased linearly according to load amplitude $\textit{\Delta}P$. In this study loading condition applied to turbine blade is predicted by the relation between the gradient of $R_q$ to $\textit{\Delta}K$ and load amplitude $\textit{\Delta}P$.

• Korean Journal of Plant Taxonomy
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• v.35 no.2
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• pp.115-127
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• 2005

Two anatomical features of leaves, transverse section of midribs and petioles, were examined for nine species of five genera of Thymelaeaceae, Daphne L. -4 spp., Diarthron Turcz. -1 sp., Edgeworthia Meisn. -1 sp., Stellera L. -1 sp., Wikstroemia Endl. -2 sp., using light microscopy and scanning electron microscopy. In terms of shape of upper side, three types were observed, i.e., flattened, depressed, and raised. Outline of petioles is mostly semi-circular or circular in transverse section, with two distinct wings/weakly developed wings or without wings. Other characters besides anatomical features of leaves such as vascular bundle tissues, crystal, tannin are also described in details. Finally, we briefly discussed the systematic significance of the anatomical features of leaves for identification of Korean Thymelaeaceae.

• Korean journal of applied entomology
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• v.41 no.4
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• pp.255-261
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• 2002

Tomato russet mite, Aculops lycopersici Massee (Acari. Eriophyidae) was recorded in Korea and their SEM observations, distribution, host range, development on different temperature, and chemical control method were studied. Tomato russet mite is a microscopic animal (134.9 $\mu\textrm{m}$) with 2 pairs of legs which had 4 rays of feathered craw. Infected leaf turn reddish brown, stem loss hair, become shiny or surface cross-cracked, and shoot wilted or shrunk. Surface of fruit around fruit stalk appeared rusted or cross-cracked. It was found in glass greenhouse at Buyeo and Yuseong in Chungnam Province, Pyeongchang in Gangwon Province, and Chilgok and Guryongpo in Gyeongbuk Province. Convolvulus, black nightshade, chinese lanternplant, eggp1ant, morning glory, petunia, potato, pepper, tobacco and tomato were confirmed as a host plant in inoculation test. It could develop at temperature around $15-30^{\circ}C$, it took 6-11 days from eggs to adult, higher temperature shorten its life cycle. Female lived longer than male and it lived as long as 12 days at 25-28"C. Among acaricides tested, fenazaquin and cypermethrin were most effective.tive.