• Title/Summary/Keyword: In-situ

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In Situ Scanning Tunneling Microscope of Cyanide and Thiocyanate Adsorption on Pt(111)

  • Yau, Shueh-Lin;Kim, Youn-Geun;Itaya, Kingo
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.723-730
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    • 1995
  • Cyclic voltammetry and in situ STM were employed to examine the interfacial structures of a Pt(111) electrode in 0.1 mM KCN (pH9.5) and 0.1 mM KSCN (pH7) solutions. In situ STM atomic resolution revealed well ordered (2${\surd}$3${\times}$2${\surd}$3)$R30^{\circ}$-6CN and ($2{\times}2$)-2SCN structures within the double layer charging region. Six CN adsorbates formed a hollow hexagon, which embraced a coadsorbed $K^+$ cation. In contrast, the coadsorbed $K^+$ cations on the SCN covered Pt(111) were poorly ordered, despite adsorbed SCN formed a long range ordered ($2{\times}2$)-2SCN adlattice. In situ STM revealed the pronounced influence of potential in controlling the structures of compact layers at the proximity of a Pt electrode. Cathodic polarization facilitated the replacement of the coadsorbed cations by protons.

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Influences of Power Fluctuation on In-Situ Ground Thermal Response Testing (지중 열반응 현장시험에서 소비전력 변동의 영향)

  • Kim, Jin-Sang;Park, Keun-Woo
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.707-712
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    • 2006
  • Knowing the ground thermal conductivity is very importnat in designing ground heat exchangers. Knowledge of the ground soil and rock composition information dose not guarantee the prediction of accurate thermal information. In Situ testing of ground heat exchangers is becoming popular. However, in situ testing are performed at construction sites in real life. Adequate data collection and analysis are not easy mainly due to poor power quality. Power fluctuation also causes the fluctuation of received data. The power quality must be maintained during the entire in situ testing processes. To accurately analyse the test data, the understanding of the response of the power fluctuation is essential. Testing under the power quality varied by tester is very difficult. Analyzing power variation by numerical simulation is a realistic option. By varying power in a sinosuidal manner, its effects on predicting thermal conductivity from thermal response plots made from the test data are examined.

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In-situ Structure Modification of W powder Skeleton and related Cu Infiltration Kinetics in W-Cu (W-Cu 계에서 W 분말골격의 in-situ 구조 변화와 Cu의 용침 kinetics)

  • 이재성
    • Journal of Powder Materials
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    • v.6 no.1
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    • pp.36-41
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    • 1999
  • The present work has attempted to investigate the dependence of Cu infiltration kinetics on in-situ structure modification of W powder skeleton in W-Cu system. In-situ structure modification of W skeleton by addition of 0.3wt%Ni-P eutectic alloy was designed to proceed during heat-up of the W compact for Cu infiltration process. It was found that the Ni-P added W skeleton underwent remarkable stucture change only during heating-up. its structure was composed of large necks of W particles above 0.5 in the ratio of neck to particle size and smooth pore channels. The infiltration experiment showed that the infiltration kinetics for the W-Ni-P followed well the linear relationship of h vs. $t^{1/2}$ the rate constant K of which was in good agreement with the theoretical value. On the other hand, in case of the pure W skeleton a lower K value by 20% than the theoretical one was obatined. Such discrepancy is discussed in terms of skeleton structure induced infiltration mechanics.

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Application of in situ gelling mucoadhesive delivery system for plasmid DNA as a macromolecule

  • Park, Jeong-Sook;Oh, Yu-Kyoung;Kim, Chong-Kook
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.236.1-236.1
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    • 2002
  • Mucosal administration of drug or therapeutic gene is emerging as a new route of delivery for systemic and local therapeutics. Previously. in situ gelling system has been applied to chemical drug such as acetaminophen. insulin. prostaglandin E1. and clotrimazole. Plasmid DNA has not been delivered in form of in situ gelling vehicles. To improve the intranasal absorption of plasmid DNA. we designed delivery systems composed of provide of in 냐셔 gelling and mucoadhesive polymers. (omitted)

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Enhanced Production of Digoxin by Digitoxin Biotransformation Using In Situ Adsorption in Digitalis lanata Cell Cultures

  • Hong, Hee-Jeon;Lee, Jong-Eun;Ahn, Ji-Eun;Kim, Dong-Il
    • Journal of Microbiology and Biotechnology
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    • v.8 no.5
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    • pp.478-483
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    • 1998
  • For the enhanced production of a cardiac glycoside, digoxin, using in situ adsorption by biotransformation from digitoxin in plant cell suspension cultures, selection of proper resins was attempted and the culture conditions were optimized. Among various kinds of resins tested, Amberlite XAD-8 was found to be the best for digoxin production in considering adsorption characteristics as well as the effect on cell growth. Adequate time for resin addition was determined to be 36 h from the beginning of biotransformation and the presence of resins should be as short as possible to increase the productivity. In addition, to prevent the cells from direct contact with resin particles, immobilized systems were designed and examined. Immobilization further improved the advantages of in situ adsorption. It was confirmed that the increase of the contact area for mass transfer was an important factor in utilizing an immobilized system to enhance digoxin production.

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Single-molecule fluorescence in situ hybridization: Quantitative imaging of single RNA molecules

  • Kwon, Sunjong
    • BMB Reports
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    • v.46 no.2
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    • pp.65-72
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    • 2013
  • In situ detection of RNAs is becoming increasingly important for analysis of gene expression within and between intact cells in tissues. International genomics efforts are now cataloging patterns of RNA transcription that play roles in cell function, differentiation, and disease formation, and they are demon-strating the importance of coding and noncoding RNA transcripts in these processes. However, these techniques typically provide ensemble averages of transcription across many cells. In situ hybridization-based analysis methods complement these studies by providing information about how expression levels change between cells within normal and diseased tissues, and they provide information about the localization of transcripts within cells, which is important in understanding mechanisms of gene regulation. Multi-color, single-molecule fluorescence in situ hybridization (smFISH) is particularly useful since it enables analysis of several different transcripts simultaneously. Combining smFISH with immunofluorescent protein detection provides additional information about the association between transcription level, cellular localization, and protein expression in individual cells.

Fabrication and properties of in-situ Al/AlB2 composite reinforced with high aspect ratio borides

  • Kayikci, Ramazan;Savas, Omer
    • Steel and Composite Structures
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    • v.19 no.3
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    • pp.777-787
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    • 2015
  • Production and properties of metal matrix composites reinforced with an in-situ high aspect ratio $AlB_2$ flake have been investigated. Boron 2.2wt.% was dissolved in pure Al and Al-Cu alloy at $1300^{\circ}C$ by adding directly boron oxide which resulted in 4 vol.% reinforcing phase. The in-situ $AlB_2$ flake concentration was increased up to 30 vol.% in order to increase the tensile strength of the composites. Hardness, compressive strength and tensile strength of the composite were measured and compared with their matrix. Results showed that 30 vol.% $AlB_2/Al$ composite show a 193% increase in the compressive strength and a 322% increase in compressive yield strength. Results also showed that ductility of composites decreases with adding $AlB_2$ reinforcements.

In-situ Monitoring of Matric Suctions in a Weathered Granite Soil Slope (풍화화강토 사면에서 강우로 인한 모관흡수력 변화에 대한 실험 연구)

  • 이인모;조우성;김영욱;성상규
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.509-516
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    • 2002
  • Rainfall-induced landslides in a weathered granite soil slope have mostly relative shallow slip surfaces above the groundwater table The pore-water pressure of soil above the groundwater table is usually negative. This negative pore-water pressure(or matric suction) has been found to make a large contribution to the slope stability. Therefore, the variation of in-situ matric suction profiles with time in a soil slope should be understood. In this study, a field measurement program was carried out from June to August, 2001 to monitor in-situ matric suctions and volumetric water contents in a weathered granite soil slope. The influence of climatic conditions on the variation of in-situ matric suctions could be found to decrease rapidly with depth. It could be found that decrement of matric suction induced by precipitation is affected not only by the amount and duration of rainfalls but also by the initial matric suction just prior to rainstorms. The soil-water characteristic from the field monitoring tends toward the wetting path of SWCC obtained from the laboratory test.

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High-Quality Epitaxial Low Temperature Growth of In Situ Phosphorus-Doped Si Films by Promotion Dispersion of Native Oxides (자연 산화물 분산 촉진에 의한 실 시간 인 도핑 실리콘의 고품질 에피택셜 저온 성장)

  • 김홍승;심규환;이승윤;이정용;강진영
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.2
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    • pp.125-130
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    • 2000
  • Two step growth of reduced pressure chemical vapor eposition has been successfully developed to achieve in-situ phosphorus-doped silicon epilayers, and the characteristic evolution on their microstructures has been investigated using scanning electron microscopy, transmission electron microscopy, and secondary ion mass spectroscopy. The two step growth, which employs heavily in-situ P doped silicon buffer layer grown at low temperature, proposes crucial advantages in manipulating crystal structures of in-situ phosphorus doped silicon. In particular, our experimental results showed that with annealing of the heavily P doped silicon buffer layers, high-quality epitaxial silicon layers grew on it. the heavily doped phosphorus in buffer layers introduces into native oxide and plays an important role in promoting the dispersion of native oxides. Furthermore, the phosphorus doping concentration remains uniform depth distribution in high quality single crystalline Si films obtained by the two step growth.

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A Comparison Method of Silver Nanoparticles Prepared by the Gamma Irradiation and in situ Reduction Methods

  • Lee, Chul-Jae;Karim, Mohammad Rezaul;Vasudevan, T.;Kim, Hee-Jin;Raushan, K.;Jung, Maeng-Joon;Kim, Dong-Yeub;Lee, Mu-Sang
    • Bulletin of the Korean Chemical Society
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    • v.31 no.7
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    • pp.1993-1996
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    • 2010
  • Silver nanoparticles has been prepared by the $\gamma$-irradiation and in situ reduction methods. Based on the Raman spectra, TEM images, X-ray Diffraction (XRD) patterns and UV-vis spectra, the in situ reduction method is more stable and the average size of the silver nanoparticles is also smaller than by the $\gamma$-irradiation reduction method. It is identified that the silver ions interacting with nonbonding electrons of oxygen atom in the carbonyl group of polyvinylpyrrolidone (PVP) by the in situ reduction method. It is also found advantages of the in situ reduction method including no additional reducing agents, without $\gamma$-irradiations treatment and the room temperature treatment suitability.