• Title/Summary/Keyword: Fine structures

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Effect of Mixed Use of Fine Aggregates on the Flowability of Ultra High Strength Concrete (잔골재 혼합사용이 석회암 굵은 골재 사용 초고강도 콘크리트의 유동특성에 미치는 영향)

  • Lee, Hong-Kyu;Kim, Min-Young;Lee, Sun-Jae;Jo, Man-Ki;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.73-74
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    • 2015
  • As this study is one related to ultra high strength concrete using crushed coarse limestone aggregates among the series of experiments for improving the economic inefficiency of the ultra high strength concretes used for high rise structures, it has analyzed the flowability of ultra high strength concrete according to the variation of blended fine aggregates. As a result of analyzing the characteristics of fresh concrete, it is determined that the application of ultra high strength concrete would be difficult in case of a mix using blended fine aggregates as lower flowability than the mix using limestone crushed fine aggregate only was shown in all mixes using blended fine aggregates.

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Crystal Structure of $TiO_2-SnO_2$ Fine Powders Prepared by Coprecipitation (공침법에 의해 제조된 $TiO_2-SnO_2$ 미분말의 결정구조)

  • 이종흔;박순자
    • Journal of the Korean Ceramic Society
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    • v.30 no.9
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    • pp.740-746
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    • 1993
  • TiO2-SnO2 fine powders prepared by coprecipitation from TiCl4-SnCl4 aqueous solution, and their crystal structures were studied. All the TiO2-SnO2 fine powders calcined at 180~$700^{\circ}C$ showed the complete solid solution between TiO2(rutile structure) and SnO2(rutile structure). This crystal structure of TiO2-SnO2 powders is thought to be originated mainly from the heterogeneous nucleation of Ti-hydroxde on the Sn-hydroxide with coherent structure.

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Application on the New Technology of Construction Structures Disaster Protection Management based on Spatial Information

  • Yeon, Sangho
    • International Journal of Internet, Broadcasting and Communication
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    • v.10 no.3
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    • pp.136-145
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    • 2018
  • The disaster monitoring technique by combination of the measurement method and the fine precision of the sensor collecting the satellite-based information that can determine the displacement space is available in a variety of diagnostic information and the GIS/GNSS by first sensor it is being requested from them. Be large and that the facility is operated nationally distributed torsional displacement of the terrain and facilities caused by such natural disasters progress of various environmental factors and the surroundings. To diagnose this spatial information, which contains the various sensors and instruments tracks the precise fine displacement of the main construction structures and the first reference in the Geospatial or more three-dimensional detailed available map and location information using the installed or the like bridges and tunnels produced to a USN/IoT change at any time, by combining the various positioning analysis of mm-class for the facility main area observed is required to constantly in the real time information of the USN/IoT environment sensor, and to utilize this as a precise fine positioning information by UAV/Drone to the precise fine displacement of the semi-permanent infrastructures. It managed to be efficient management by use of new technologies, analyzing the results presented to a method capable of real-time monitoring for a large structure or facility to construction disaster prevention.

Alkali-Swollen Structures of Native Cellulose Fibers by X-ray Diffraction Methods (X선회절법(線回折法)에 의한 천연 셀룰로오스 섬유의 알칼리 팽윤구조(膨潤構造))

  • Kim, Nam-Hun
    • Journal of the Korean Wood Science and Technology
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    • v.20 no.1
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    • pp.38-45
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    • 1992
  • Fine and alkali-swollen structures of native cellulose fibers were investigated by x-ray diffraction methods. The results of fine structures are shown in Table 1. In meridional x-ray diffractograms, the relative intensity ratio R of (002) to (004) for cellulose I was ca. 0.05 and for regenerated cellulose it was ca. 0.45. It was considered that the transformation from cellulose I to cellulose II resulted from the packing or conformational change of cellulose chain. Finally. although cellulose I was not detected in the alkali-swollen celluloses treated for 1 hr to 24 hrs, washing and drying them resulted in the generation of considerable amounts of cellulose I and the amount decreased with increasing alkali duration.

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A fundamental study on the sulphate-resistant mortar using waste glass fine powder and meta-kaolin according to various fine aggregates (잔골재 종류에 따른 폐유리 미분말 및 메타카올린을 사용한 내황산염 모르타르에 관한 기초적 연구)

  • Jeong, Dongwhan;Park, Junhui;Ahn, Taeho;Park, Yeongsik;Sho, Kwangho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.27 no.3
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    • pp.115-121
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    • 2017
  • The degradation of the concrete due to deterioration factors, such as corrosion of steel bars, cracks and structural strength of reinforced concrete structures, is a social problem. Especially, concrete structures constructed in seawater, underground water, waste water treatment facilities and sewerage are subject to chemical attack by acid and sulphate. Therefore, this study was conducted to compare sulfated glass and fine aggregate of slag using waste glass fine powder and meta kaolin. The results showed that the slag fine aggregate showed better sulfate resistance than the river sand, and the fine powder of waste glass showed the best performance at 3 % displacement.

Pulmonary Nocardiosis Diagnosed by Fine Needle Aspiration - A Case Report - (세침흡인 세포학적 검사로 진단한 폐의 Nocardiosis - 1예 보고 -)

  • Yim, Hyun-Ee;Park, Kwang-Hwa
    • The Korean Journal of Cytopathology
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    • v.6 no.2
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    • pp.169-173
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    • 1995
  • Nocardia, aerobic members of the order of Actinomycetaceae, produces infections in human lung. Nocardial infection is associated with underlying diseases of immuno-suppression or treatment with corticosteroid. It is difficult to detect Nocardia by sputum examination or histologic sections and it has rarely been diagnosed by fine needle aspiration of the lung. We describe a case of pulmonary nocardiosis in a 72 year-old man, diagnosed by fine needle aspiration, which was confirmed by culture of aspirates. The aspirates showed neutrophil-predominant inflammatory cells with microorganisms demonstrated by Gomori methenamine silver and Gram stain. The organisms had characteristic long blanching filamentous structures. The lesions on chest X-ray were in resolution with antimicrobial therapy.

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