• Title/Summary/Keyword: Fractured

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The Clinical Study of Zygomatic Complex Fracture (협골 골절의 임상적 연구)

  • Cho, Byoung-Ouck;Lee, Yong-Chan;Kim, Tae-Young;Koh, Back-Jin
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.11 no.1
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    • pp.63-68
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    • 1989
  • The zygoma is a heavy bone that composes a part of orbit and it was considered to be rarely fractured. However the rate of zygoma injury is increasing due to the outdoor life and motorvehicle accidents. The authors use a bone hook for direct reduction of fractured zygoma in combinaton with a miniplate osteosynthesis for rigid fixation and we reconstruct an infraorbital with a Lyodura.

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Finite Difference Modeling for Scale-Dependent Dispersivity in a Fractured Medium

  • Han, Choongyong;Kang, Joe M.;Choe, Jonggeun
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2002.04a
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    • pp.102-105
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    • 2002
  • A new finite difference model is developed for solute transport in a fractured medium that can consider advection, adsorption, first-order decay, and scale-dependent dispersivity of individual fractures. In the model, the dispersivity of individual fractures is employed as a variable increasing with travel distance from a source. The model is verified using an analytical solution for a single fracture. A solution from the new model is independent of the outlet boundary condition of fractures, and has little numerical dispersion error.

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국가지하수 관측망의 양수시험 자료 해석을 통한 대수층 특성 분석

  • 전선금;구민호;김용제;강인옥
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.04a
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    • pp.487-491
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    • 2004
  • For tile hydrogeological data of the National Groundwater Monitoring Wells(NGMW), a statistical analysis is made to reveal aquifer characteristics of the country. Results of the pumping and recovery test are classified into 4~5 types by the pattern of drawdown and residual drawdown curves. The analysis of aquifer characteristics shows that the hydraulic conductivity of alluvial aquifers is greater than that of fractured-rock aquifers. The hydraulic conductivity of alluvial aquifers slightly increases as the distance to the discharge area decreases. 77.5% of the NGMWs, where the distance to the discharge area is more than 100m, shows the constant head boundary. This result suggests that the fractured and the alluvial aquifers are fairly interconnected, and water can be supplied from one aquifer to tile other where pumping tests are performed. It is analyzed that the wells showing the impermeable boundary are influenced by small scale of aquifers, poor aquifer transmissivities, and impermeable layers.

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Analysis on the Fatigue Fracture Surface of Gas Piping Material using the X-Ray Fractography (X-선 프랙토그라피에 의한 가스배관재의 피로파면해석)

  • Lim, Man-Bae
    • Journal of the Korean Society of Safety
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    • v.17 no.1
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    • pp.18-24
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    • 2002
  • This study verified the relationship between fracture mechanics parameters(${\Delta}K,\;K_{max}$) and X-ray parameters ($(\sigma}_r,;B$) for G365 steel at elevated temperature up to $300{\circ}C$. The fatigue crack propagation test were carried out and X-ray diffraction technique according to crack length direction was applied to fatigue fractured surface. The residual stress on the fracture surface was found to increase in low ${\Delta}K$ region, reach to a maximum value at a certain value of $K_{max}$ or ${\Delta}K$ and then decrease. Residual stress was independent on stress ratio by arrangement of ${\Delta}K$ and half value breadth was independent by the arrangement of $K_{max}$. The equation of ${\sigma}_r-{\Delta}K$ was established by the experimental data. Therefore, fracture mechanics parameters could be estimated by the measurement of X-ray parameters.