• Proceedings of the Membrane Society of Korea Conference
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• 1995.04a
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• pp.24-25
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• 1995

한외여과법은 역삼투법과 정밀여과법의 중간영역의 막분리법으로 공경이 1 nm - $0.05\mum$ 정도이며 실제로 분리는 표면층에서 일어난다. 그러므로 분리특성이 없는 막하부의 저항을 줄여야 분리성능을 유지하며 투과유량을 늘릴 수 있다. 폴리비닐피롤리돈 (PVP)은 openpore구조를 형성시키면서 막내의 친수성을 증가시키는데 광범위하게 적용되고 있다. 본 연구에서는 폴리비닐피롤리돈을 폴리에테르 이미드 (polyetherimide)에 첨가시켰을 때 막내에서 구조형성과 한외 여과성는에 어떠한 영향을 미치는가 연구하였다. 막의 구조를 분석하기 위해서 주사전자현미경이 널리 사용되고 있다. 그런데 주사전자현미경은 시료의 표면에 전도성을 갖는 금을 코팅해야 하기 때문에 한외여과막의 표면을 관찰하기에는 매우 어렵다. 그래서 본 연구에서는 Atomic Force Microscope (AFM)를 사용하여 코팅과정없이 막표면을 관찰하였고 한외여과특성과 상관관계를 연구하였다.

• Journal of the Korean institute of surface engineering
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• v.29 no.1
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• pp.15-25
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• 1996

자동차엔진의 피스톤-링에 응용할 목적으로 플라즈마 용사 기술로 피막한 몰리부덴늄 및 코발트 합금 피막 층의 마모성질을 비교 조사하였다. Ball-on-disc 형태의 마모기를 사용하여 상온 및 대기 중에서의 마모 및 마찰거동에 대하여 조사하였다. 용사 층의 미세경도 시험도 행하였으며, 용사층의 결정구조를 알기 위해 용사층을 x-선 회절 방법으로 분석하였다. 주사전자현미경을 사용하여 마모면의 표면 형상을 관찰하였다. 여러 용사조건으로 만든 용사층의 미세경도치와 마모거동과의 상관관계를 이해하려고 시도하였다. 주사전자현미경과 EDX를 사용하여 마모시 화학반응층과 마모기구를 규명하고자 하였다. 모리부덴늄 및 코발트 합금 분말을 각각 플라즈마 용사층의 단면을 관찰하여 마모기구을 비교하였다.

• Journal of the Korean Ceramic Society
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• v.41 no.6
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• pp.439-443
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• 2004

SrAl$_2$O$_4$ powder was prepared by polymerized complex method and its nucleation was observed at different temperatures and times. Problems of inhomogeneity and high synthesis temperature induced by solid state reaction could be solved by using polymeric precursors. The process of decomposition by heat treatment above 40$0^{\circ}C$ was observed by Scanning Electron Microscopy (SEM) and elemental analyzer. Crystallization of SrAl$_2$O$_4$ occured at about 90$0^{\circ}C$ and its crystalline size. which was determined by using Transmission Electron Microscopy (TEM) and X-Ray Diffractometer (XRD). was about 30∼50 nm.

• Polymer(Korea)
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• v.35 no.5
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• pp.390-394
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• 2011

Effects of silver nanoparticles on the polymerization rate and morphology of poly(vinyl acetate) (PVAc)/silver microspheres prepared by suspension polymerization of VAc were investigated. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and atomic absorption spectrometry were used to characterize the morphology and properties of the PVAc/silver microspheres. Due to the change of hydrophilicity of silver nanoparticles, appearance of the microspheres having golf ball-like convave surfaces was observed. Under controlled concentration of surfactant, PVAc/silver microspheres with various hollow structures were synthesized. In the case of silver nanoparticles modified by surfactant, the polymerization rate increased slightly. PVAc/silver microspheres with a conversion up to 80% were prepared via suspension polymerization.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.69-70
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• 2003

According to topographical methods, the chicken spermatogonia was located in basal membrane of seminiferous tubules. It has large nuclei and mitochondria and proliferated with cellular bridges. Immunohistochemistry data showed that anti-SSEA-1 antibody specifically reacted with $\textrm{A}_{pr}$ and $\textrm{A}_{al}$ type spermatogonia. Lectin, STA and integrin-6, -1 were also specific to $\textrm{A}_{s}$ type spermatogonia.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.4
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• pp.595-607
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• 1999

The purpose of this in vitro study was to evaluate the efficacy of self-etching primer which was developed to simplify the bonding procedures by measuring the shear bond strength and observing the interfacial morphology. 90 flat dentinal surfaces were prepared by grinding the buccal and lingual areas of caries-free human deciduous molars. After bonding of composite resin to sample surfaces according to the manufacturer's direction and thermocycling, shear bond strengths were measured using Universal testing machine(Instron). Another groups of specimens were treated by hydrochloric acid to secure the resin only and those tags were evaluated under SEM for their length and forms and the morphology of the bonding sites were also observed. The result as follows. 1. Group III showed higher shear bond strength than group I and II but no statistically significant difference was founded between group I and II(p>.05). 2. Adhesive failure was predominant in group II whereas dentin detachment was the main failure pattern in group I and III. 3. Relating long resin tags of $100-200{\mu}m$ were observed in samples of all groups under SEM. In group I, homogeneously long resin tags were arranged rather tight whereas rather loosely arranged resin tags of various length were found in group II. Lateral branching of resin tags was the characteristic finding observed in group III.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.97-97
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• 2015

전 세계적으로 화석연료의 고갈 및 환경오염 문제를 해결하기 위해 신재생에너지에 대한 관심이 급증하고 있다. 이러한 신재생에너지에는 수소 에너지, 자연 에너지(태양열, 지열 등), 바이오 매스 에너지 등이 포함된다. 이 중 수소 에너지는 지구상에 풍부하게 존재하고 있는 물과 탄화수소로부터 얻어지며, 연소 시에도 다시 물을 형성하여 오염 물질을 배출하지 않는 차세대 무공해 에너지원으로써 주목을 받고 있다. 수소 제조를 위한 공정에는 수증기 개질 공정(steam reforming), 부분 산화(partial oxidation) 및 자열개질(autothermal reforming) 등이 있으며 실제로 생산되는 대부분의 수소는 탄소/수소비(1:4)가 높은 메탄($CH_4$) 가스를 이용한 메탄 수증기 개질 공정(steam methane reforming)을 통하여 제조된다. 이 때 수소 제조의 고효율화 및 저비용화를 위해서는 반응물에 대한 높은 선택도, 고활성도 및 높은 안정성을 갖는 촉매가 반드시 필요하며, 대표적으로 Ni, Pt, Ru 등이 보고되고 있다. 이러한 촉매들은 대부분 세라믹 pellet 형태로 제작되어 왔으나 열전도도가 낮고 물리적 충격에 취약하다는 단점이 존재한다. 따라서 우리는 이러한 단점을 극복하고, 촉매의 활성을 높이기 위하여 다공성 금속 합금 폼을 촉매 지지체로 도입하였다. 또한, 다공성 금속 합금 폼 표면에 촉매의 분산 및 안정성을 향상시키기 위해 지지체와 촉매 사이에 원자층 증착법을 이용하여 inter-layer를 도입하였다. 이들의 구조, 형태, 및 표면의 화학적 상태는 주사전자현미경, EDS (energy dispersive spectroscopy)가 탑재된 주사전자현미경, X-선 회절, 및 X-선 광전자 분광법을 이용하여 규명하였다. 더하여 정전압-전류 측정법 및 유도 결합 플라즈마 분광 분석기을 이용하여 전기 화학 반응을 유도하고, 반응 후 전해질의 성분분석을 통해 촉매와 지지체 간의 안정성을 평가하였다. 따라서 본 결과들은 한국진공학회 하계정기학술대회를 통해 좀 더 자세히 논의될 것이다.

• Journal of Sericultural and Entomological Science
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• v.27 no.2
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• pp.28-39
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• 1985

The structural and useful characteristics of silk habutae treated with silicone resin by emulsion finishing method were studied. The results were obtained through crease recovery test, water repellency test, scanning micrograph observation, amino acid analysis, X-Ray diffraction analysis, and Fourier Transform Infrared Spectroscopy. The results are summarized as follows; 1) The improvement in crease recovery of silk habutae finished with silicone resin, was observed b soaping treatment and curing conditions. 2) The higher water repellency and stiffness in silk fabrics finished with silicone resin was found by the fabric inspection and the scanning electron microscopic observation. It is suggested that silicone resin impregnated into the void of silk fibroin. 3) The polar side chains of amino acid composition were decreased, when the silicone resin was treated on silk fibroin. 4) Through Amino acid analysis of silicone resin finished fibroin, the different amounts of amino acid composition was indicated due to silk fibroin silicone polymer reaction and the structural difference of its fibroin were also proved by X-ray diffractograms. 5) The functionality of the siloxane compound may be deduced from the silicone finished silk habutae by Fourier Transform Spectroscopy. It was concluded from the above results that the useful characteristics of silk fabric can be improved by silicone resin finishing.

• Korean journal of food and cookery science
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• v.8 no.1
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• pp.9-14
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• 1992

The morphological properties of acorn starch granules and starch gels were examined with scanning electron microscope and X-ray diffractometer. The shape of acorn starch granule was rounded triangular and some elliptical. The size distribution of starch granule was also analyzed. The mean value of minor axis, major axis and the ratio of those were 4.785 $\mu\textrm{m}$, 7.30 $\mu\textrm{m}$ and 0.68, respectively. The surface micro-structure of acorn starch gels were investigated by SEM. Acorn crude and refined starch gel were very different in surface micro-structure. X-ray diffraction pattern of acorn starch was C-type, and the pattern of acorn starch gels were extremely different because of disintegration of starch granules by gelatinization. The diffraction intensity of acorn refined starch gel was slightly higher than crude starch gel.

• Korean Journal of Veterinary Research
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• v.24 no.2
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• pp.213-226
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• 1984

Scanning electron microscope (Model; SEM ISI-DS-130) was used to observe the fine surface structures of the predominant cattle tick Haemaphysalis longicornis Neumann 1901 (Acarina: Ixodidae) in Korea and some SEM microphotographs were presented in this pictorial monograph. Brief descriptions of the main contents are consisted of followings; L Mean body size is 2.43mm in unfed males and 2. 58mm in unfed females, the eyes are absent. 2. The scutums are inornated but there are some short-setae on the surface of the body. 3. The festoons on the dorso-marginal part of the body are present and segmented with 11 sectors. 4. The cornua is well-developed and the bypostome dentition is usually 5/5 in both sexes but rarely 4/4 also seen. 5. There is no dorsal projection on the anteriointernal margin of the palpal article 2, howevever, there are well developed dorso-internal setae with setal fossa on it. 6. The joints of the legs (Coxatrochanter and trochanter coxa, etc) are well developed.