• Title/Summary/Keyword: Specific surface are

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Nano SPR Biosensor for Detecting Lung Cancer-Specific Biomarker (폐암 바이오마커 검출용 나노SPR 바이오센서)

  • Jang, Eun-Yoon;Yeom, Se-Hyuk;Eum, Nyeon-Sik;Han, Jung-Hyun;Kim, Hyung-Kyung;Shin, Yong-Beom;Kang, Shin-Won
    • Journal of Sensor Science and Technology
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    • v.22 no.2
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    • pp.144-149
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    • 2013
  • In this research, we developed a biosensor to detect lung cancer-specific biomarker using Anodic Aluminum Oxide (AAO) chip based on interference and nano surface plasmon resonance (nanoSPR). The nano-porous AAO chip was fabricated $2{\mu}m$ of pore-depth by two-step anodizing method for surface uniformity. NanoSPR has sensitivity to the refractive index (RI) of the surrounding medium and also provides simple and label-free detection when specific antibodies are immobilized to the Au-deposited surface of nano-porous AAO chip. To detect the lung cancer-specific biomarker, antibodies were immobilized on the surface of the chip by Self Assembled Monolayer (SAM) method. Since then lung cancer-specific biomarker was applied atop the antibodies immobilized layer. The specific reaction of the antigen-antibody contributed to the change in the refractive index that cause shift of resonance spectrum in the interference pattern. The Limit of Detection (LOD) was 1 fg/ml by using our nano-porous AAO biosensor chip.

Studies on the Adsorptive Properties of Korean Kaolin (II) - Micromeritic Study of Korean Kaolin (국산 카올린의 흡착성에 관한 연구(II) - 분체학적 고찰)

  • 이계주
    • YAKHAK HOEJI
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    • v.29 no.4
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    • pp.176-182
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    • 1985
  • As a part of the studies on adsorptive properties of Korean halloysite clays, Hadong white clays of premium grade were examined for geometric pore structured by mercury porosimetry and for specific surface areas by nitrogen adsorption according to the BET procedure. Three size fractions of the native clay sample were derived from passage BS #100, #200 and #325 meshes, respectively. Several parameters lhus observed in relation to the pore structures are shown below: 1. The size fraction of BS #100, #200 and #325 show internal pore volumes of 25.3, 30.2 and $35.0m^2g^{-1}$, respectively. 2. In the distribution curves of the cumulative pore volume against pore diameter, it has been shown that the larticle sizes, the steeper the distribution over the larger ranges of pore diameters. The converse is true the smaller particles. 3. Internal pore areas increase with decrease in pore sizes. It follows that the pores having diameters of $\leq$0.1$\mu\textrm{m}$ are responsible for more than 90% of the total pore area. 4. The behaviour of nitrogen adsorption can be best described by BET type IV isotherm. Further, the hysteresis loops of the adsorptiondesorption curves become narrower with decresing particle sizes. 5. The specific surface areas observed for the fractions of BS #100, BS #200 and BS #325 are 34.6, 35.4 and 43.2m $^2g^{-1}$, respectively. and the calcined clay of BS #325 has a specific surface area near $30.4m^2g^{-1}$.

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A Study of the Optimum Pore Structure for Mercury Vapor Adsorption

  • Kim, Byung-Joo;Bae, Kyong-Min;Park, Soo-Jin
    • Bulletin of the Korean Chemical Society
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    • v.32 no.5
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    • pp.1507-1510
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    • 2011
  • In this study, mercury vapor adsorption behaviors for some kinds of porous materials having various pore structures were investigated. The specific surface area and pore structures were studied by BET and D-R plot methods from $N_2$/77 K adsorption isotherms. It was found that the micropore materials (activated carbons, ACs) showed the highest mercury adsorption capacity. In a comparative study of mesoporous materials (SBA-15 and MCM-41), the adsorption capacity of the SBA-15 was higher than that of MCM-41. From the pore structure analysis, it was found that SBA-15 has a higher micropore fraction compared to MCM-41. This result indicates that the mercury vapor adsorptions can be determined by two factors. The first factor is the specific surface area of the adsorbent, and the second is the micropore fraction when the specific surface areas of the adsorbent are similar.

Characterization of Surface Properties of $BaTiO_3$ Powder by XPS

  • Chun, Myoung-Pyo;Cho, Jung-Ho;Kim, Byung-Ik
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.678-679
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    • 2006
  • The effects of particle size on the surface properties of hydro-thermally synthesized barium titanate powders were investigated by means of particle size analysis, specific surface area, SEM, zeta potential and XPS. Particle sizes were measured by laser light scattering and are in the range of 150 to 1100nm. Zeta potential increased with increasing particle size and it was large minus value in the range of particle size from 500 to 900nm, which seems to be related with the dissolution of $Ba^{2+}$ ion in these particle sizes from the analysis of surface properties by XPS.

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Evaluation of Microscopic Wear Characteristics for CVD TiN Coatings with SEM Tribosystem (SEM Tribosystem에 의한 CVD TiN막의 미시적 마모 특성 평가)

  • 문봉호
    • Journal of the Korean institute of surface engineering
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    • v.37 no.3
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    • pp.137-145
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    • 2004
  • This study surveys the microscopic wear of CVD TiN coatings in repeated sliding, using the SEM Tribosystem as in-situ system. According to the research, the depth of wear groove and the specific wear amount are changed by the transition of the microscopic wear mode. This investigation leads to the fact that the change of wear characteristics produces the transition of the wear mode. In this survey, four modes are observed for CVD TiN coatings with the thickness of 1.6$\mu\textrm{m}$: ploughing, powder formation, flake formation and coating delimitation. The microscopic wear properties is quantitatively evaluated in terms with the microscopic wear mode and the specific wear amount. These relationships prove that the observation of wear modes with a SEM Tribosystem is useful to evaluate wear properties.

Development of the GIS Method for Extracting a Specific Geomorphic Surface of Coastal Terrace at Gampo Area, Southeastern Coast in Korea (GIS를 이용한 해안단구 지형면 분류 기법 연구 - 감포지역을 사례로 -)

  • 박한산;윤순옥;황상일
    • Journal of the Korean Geographical Society
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    • v.36 no.4
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    • pp.458-473
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    • 2001
  • The classified map of geomorphic surfaces is the most basic data for the geomorphological research. Up to recent days, the traditional methods extracting specific geomorphic surfaces are accomplished by analyzing the aerial photographs and topographical maps, and field works. Also it needs a lot of time and expertness. Furthermore it is difficult to gain the aerial photographs in Korea. Since digital maps in Korean Peninsula are almost completed recently, we tried to extract specific surfaces by analyzing the characteristics of marine terraces based on the level of paleoshoreline and slope analysis on the terrace surface using GIS. However, research used GIS was hardly found up to date, therefore many problems are not be solved yet. The aim of this study is to develop the more efficient and objective method for the extraction and classification of specific geomorphic surfaces by using GIS in Gampo-eup, Gyeongju city, Southeastem Coast in Korea, where a lot of traditional research has already accomplished. For this aim, we have designed the process of extracting specific geomorphic surfaces, chosen the factors that was Gyeongiu city, Southeastem Coast in Korea, where a lot of traditional research has already accomplished. For this aim, we have designed the process of extracting specific geomorphic surfaces, chosen the factors that was suitable for classification of specific geomorphic surface, and presented method of setting up optimum criteria of extraction. As last, effectiveness and problems of these methods were investigated through conincidence rate and error rate.

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Effect of Intermediate Layer Coated Diamond Particles on Performance of Diamond Tool (다이아몬드 입자에 형성된 중간층이 다이아몬드 공구 성능에 미치는 영향)

  • Son, Kyung-Sik;Lee, Jung-Hoon;Choi, Yong-Je;Jung, Uoo-Chang;Chung, Won-Sub
    • Journal of the Korean institute of surface engineering
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    • v.46 no.5
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    • pp.216-222
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    • 2013
  • In order to improve the performance of electrodeposited diamond-nickel composite, surface modification of diamond particles was carried out using powder immersion reaction assisted coating (PIRAC). Titanium and chromium were selected as coating elements, which are known as carbide former. With respect to the powder elements, various phases were formed on diamond; metallic Ti and TiC for Ti powder, $Cr_3C_2$ for Cr powder, and TiC and $Cr_3C_2$ for Ti-Cr mixed powder. Surface modified diamond particle showed higher specific surface area, especially Ti coating induced considerable increase of specific surface area. The increase of specific surface area suggests increase of surface roughness, and that was confirmed by surface observation using FE-SEM. In addition, wear properties of diamond-nickel composite including surface modified diamonds were improved, and Ti coated diamond showed the highest performance. The wear property of diamond-nickel composite is dependent on adhesion strength between diamond particle and nickel layer. Therefore, surface modification of diamond particle by PIRAC increasing surface roughness is effective to improve the properties of diamond-nickel composite.

A Study on the Thermal Behaviour of Layered Solids in Sliding Contacts (얇은 layer가 존재하는 접촉표면의 열적거동에 대한 연구)

  • 안효석
    • Tribology and Lubricants
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    • v.5 no.2
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    • pp.42-47
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    • 1989
  • The thermal behaviour of layerd solids, typified in practice by surface coated materials, is evaluated for the specific case of a fast moving heat source. This is intended to represent the particular instance of solids in sliding contact and the consequences of friction. The finite difference method has been utilised to establish the temperature distributions at the surface and also the sub-surface region for coating materials which are either less conductive or more conductive than the substrate to which they are attached. The effects of variation in layer thickness, and also the load, speed and friction coefficient, are evaluated.

Immobilized Small Sized Manganese Dioxide Sand in the Remediation of Arsenic Contaminated Water

  • Tiwari, Diwakar;Laldawngliana, C.;Lee, Seung-Mok
    • Environmental Engineering Research
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    • v.19 no.1
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    • pp.107-113
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    • 2014
  • Small sized manganese dioxide particles are immobilized onto the surface of sand by the wet impregnation process. The surface morphology of the solid, i.e., immobilized manganese dioxide natural sand (IMNS) is performed by taking scanning electron microscope images and characterized by the X-ray diffraction data. The specific surface area of the solid is obtained, which shows a significant increase in the specific surface area obtained by the immobilization of manganese dioxide. The $pH_{PZC}$ (point of zero charge) is found to be 6.28. Further, the IMNS is assessed in the removal of As(III) and As(V) pollutants from aqueous solutions under the batch and column operations. Batch reactor experiments are conducted for various physicochemical parametric studies, viz. the effect of sorptive pH (pH 2.0-10.0), concentration (1.0-25.0 mg/L), and background electrolyte concentrations (0.0001-0.1 mol/L $NaNO_3$). Further, column experiments are conducted to obtain the efficiency of IMNS under dynamic conditions. The breakthrough data obtained by the column experiments are employed in non-linear fitting to the Thomas equation, so as to estimate the loading capacity of the column for As(III) and As(V).

Effect of Specific Interaction of Multi-Ligands on the Specific Interaction between Particle and Cell (멀티 리간드의 특이적 상호작용이 입자-세포간 상호작용에 미치는 영향)

  • Yoon, Jung Hyun;Lee, Sei Young
    • Journal of Biomedical Engineering Research
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    • v.43 no.2
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    • pp.94-101
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    • 2022
  • Recent advancement of micro/nano technology enables the development of diverse micro/nano particle-based delivery systems. Due to the multi-functionality and engineerability, particle-based delivery system are expected to be a promising method for delivery to the target cell. Since the particle-based delivery system should be delivered to the various kinds of target cell, including the cardiovascular system, cancer cell etc., it is frequently decorated with multiple kinds of targeting molecule(s) to induce specific interaction to the target cell. The surface decorated molecules interact with the cell surface expressed molecule(s) to specifically form a firm adhesion. Thus, in this study, the probability of adhesion is estimated to predict the possibility to form a firm adhesion for the multi-ligand decorated particle-based delivery system.