• Title/Summary/Keyword: in-situ analysis

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Korean Three Dimensional In-situ stresses and Tunnel Analysis Considering These Stresses (한반도 3차원 지중응력과 이를 고려한 터널해석에 대한 연구)

  • 김동갑;박종관;김수정
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.03a
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    • pp.97-104
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    • 2001
  • The magnitude and the orientation of in-situ stresses contribute to ground displacement and stresses in the field of underground space. This paper investigates in-situ stresses at various depth on the basis of 392 data which were determined by over-coring and hydro-fracturing test methods in the Korea peninsula. The result shows that in-situ stress distribution are more or less non-uniform through the Granite and Gneiss sub-area, and that the K-value in the Volcanic sub-area are below 1 at the deep depth. Also, the result of three dimensional numerical analyses of tunnel shows that the direction and magnitude of displacement around tunnel are much effected by the stress difference between the maximum and the minimum horizontal stress.

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Three Dimensional In-situ Stress Distribution in the Southern Korean Peninsula and Its Application in Tunnel Analysis (한반도 3차원 지중응력의 분포와 이를 고려한 터널해석에 대한 연구)

  • 김동갑;박종관
    • Journal of the Korean Geotechnical Society
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    • v.18 no.2
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    • pp.65-74
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    • 2002
  • The measurement of in-situ stress is essential to estimate the ground displacement and the stress distribution of a tunnel and an underground structure. In this study, the in-situ stress distribution of the Southern Korean peninsula was re-evaluated by the new 380 in-situ data which were determined by overcoring and hydrofracturing methods, and the three-din erosional numerical analysis of tunnelling was performed. The results of in-situ stress distribution show that the distribution of horizontal stress tends to be more irregular in metamorphosed(gneiss) and granite areas than in sedimentary and volcanic areas. The ratio of horizontal to vertical stresses(K-value) in volcanic area is less than 1 below the depth of 150m. The direction and magnitude of three dimensional in-situ stresses were shown simultaneously in a figure for the first time in Korea. The three-dimensional numerical analysis of tunnelling indicates that the orientation and magnitude of displacement around a tunnel are controlled mainly by the difference between the maximum and minimum horizontal stresses.

Technical Investigation into the In-situ Electron Backscatter Diffraction Analysis for the Recrystallization Study on Extra Low Carbon Steels

  • Kim, Ju-Heon;Kim, Dong-Ik;Kim, Jong Seok;Choi, Shi-Hoon;Yi, Kyung-Woo;Oh, Kyu Hwan
    • Applied Microscopy
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    • v.43 no.2
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    • pp.88-97
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    • 2013
  • Technical investigation to figure out the problems arising during in-situ heating electron backscatter diffraction (EBSD) analysis inside scanning electron microscopy (SEM) was carried out. EBSD patterns were successfully acquired up to $830^{\circ}C$ without degradation of EBSD pattern quality in steels. Several technical problems such as image drift and surface microstructure pinning were taking place during in-situ experiments. Image drift problem was successfully prevented in constant current supplying mode. It was revealed that the surface pinning problem was resulted from the $TiO_2$ oxide particle formation during heating inside SEM chamber. Surface pinning phenomenon was fairly reduced by additional platinum and carbon multi-layer coating before in-situ heating experiment, furthermore was perfectly prevented by improvement of vacuum level of SEM chamber via leakage control. Plane view in-situ observation provides better understanding on the overall feature of recrystallization phenomena and cross sectional in-situ observation provides clearer understanding on the recrystallization mechanism.

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.

A study on analysis of tunnel behaviors considering the characteristics of in-situ stress distribution in rock mass (암반응력의 분포특성을 고려한 터널거동 분석에 관한 연구)

  • Part, Do-Hyun;Kim, Young-Geun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.9 no.3
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    • pp.275-286
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    • 2007
  • In construction of a structure in underground space, in-situ stress in rock mass has great effect on the stability of the structure. Especially, the direction and magnitude of rock stress have influence on the excavation method, the choice of support and reinforcement method for establishing the stability of tunnel. Therefore, it is very important to consider the characteristics of in-situ stress in rock mass for tunnel stability analysis. In this study, a reasonable design method for underground structure was reviewed through the case study for tunnel design considering in-situ rock stress. For this purpose, the estimation for SRF (Stress Reduction Factor) as input parameter in rock classification using Q-System and the assesment for tunnel support were studied. Also, considering the characteristics of in-situ rock stress such as the magnitude of K and the direction of principal stress, the parameter studies for tunnel stability analysis were carried out. An improved method was proposed for obtaining the better results in the tunnel stability analysis.

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Synthesis Behavior of Ti-25.0~37.5at%Si Powders by In situ Thermal Analysis during Mechanical Alloying (기계적 합금화과정에서의 in situ 열분석에 의한 Ti-25.0~37.5at%Si 분말의 합성거동)

  • Byun Chang Sop;Hyun Chang Yong;Kim Dong Kwan
    • Korean Journal of Materials Research
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    • v.14 no.5
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    • pp.305-309
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    • 2004
  • Mechanical alloying (MA) of Ti-25.0~37.5at%Si powders was carried out in a high-energy ball mill, and in situ thermal analysis was also made during MA. In order to classify the synthesis behavior of the powders with respect to at%Si, the synthesis behavior during MA was investigated by in situ thermal analysis and X-ray diffraction (XRD). In situ thermal analysis curves and XRD patterns of Ti-25.0~26.1at%Si powders showed that there were no peaks during MA, indicating $Ti_{5}$ $Si_3$ was synthesised by a slow reaction of solid state diffusion. Those of Ti-27.1~37.5at%Si powders, however, showed that there were exothermic peaks during MA, indicating $_Ti{5}$ $Si_3$ and$ Ti_3$Si phase formation by a rapid exothermic reaction of self-propagating high-temperature synthesis (SHS). For Ti-27.1~37.5at%Si powders, the critical milling times for SHS decreased from 38.1 to 18.5 min and the temperature rise, ΔT (= peak temperature - onset temperature) increased form $19.5^{\circ}C$ to $26.7^{\circ}C$ as at%Si increased. The critical composition of Si for SHS reaction was found to be 27.1at% and the critical value of the negative heat of formation of Ti-27.1at%Si to be -1.32 kJ/g.

Synthesis Behavior of Ti-50.0 ~ 66.7at%Si Powders by In situ Thermal Analysis during Mechanical Alloying (기계적 합금화과정에서의 in situ 열분석에 의한 Ti-50.0~66.7at%Si 분말의 합성거동)

  • Byun Chang Sop;Lee Sang Ho;Lee Wonhee;Hyun Chang Yong;Kim Dong Kwan
    • Korean Journal of Materials Research
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    • v.14 no.5
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    • pp.310-314
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    • 2004
  • Mechanical alloying (MA) of Ti-50.0~66.7at%Si powders was carried out in a high-energy ball mill, and in situ thermal analysis was also made during MA. In order to classify the synthesis behavior of the powders with respect to at%Si, the synthesis behavior during MA was investigated by in situ thermal analysis and X-ray diffraction (XRD). In situ thermal analysis curves and XRD patterns of Ti-50.0~59.6at%Si powders showed that there were exothermic peaks during MA, indicating TiSi, $TiS_2$, and $Ti_{5}$ $Si_4$ phase formation by a rapid exothermic reaction of self-propagating high-temperature synthesis (SHS). Those of Ti-59.8~66.7 at%Si powders, however, showed that there were no peaks during MA, indicating any Ti silicide was not synthesised until MA 240 min. For Ti-50.0~59.6at%Si powders, the critical milling times for SHS increased from 34.5 min to 89.5 min and the temperature rise, $\Delta$T (=peak temperature-onset temperature) decreased form $26.2^{\circ}C$ to $17.1^{\circ}C$ as at%Si increased. The critical composition of Si for SHS reaction was found to be 59.6at% and the critical value of the negative heat of formation of Ti-59.6at%Si to be -1.48 kJ/g.

The Behavior of In-situ Top Base foundation in Granular Soil (사질토에서 현장타설 팽이기초의 거동특성)

  • Kim, Hak-Moon;Kim, Chan-Kuk
    • Journal of the Korean Geotechnical Society
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    • v.24 no.10
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    • pp.121-129
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    • 2008
  • Numerical analysis for the in-situ top base foundation (In-situ TBF) was carried out in order to investigate the effect of bearing capacity and the load delivering mechanisms in granular soil. The input data for the numerical model was prepared from the result obtained from the plate load test and full size in-situ TBF field tests. According to the result of numerical analysis, the behavior of in-situ TBF showed that bearing capacity of the foundation increased by $50{\sim}100%$ and settlement was reduced up to $1/2{\sim}1/3$ comparing to other types foundation. The effect of cone-shaped part of the in-situ TBF was as important as pile part for the improvement of foundation stability. The variation of the length of pile part indicated that the present length was proved satisfactory in terms of effectiveness.

New Method for Measurement and Validation of In-situ Sound Transmission Loss (In-situ 소음투과손실 측정 및 검증을 위한 기법 개발)

  • Lee, Hwa-Soo;Park, Hong-Cheol;Yoon, Seong-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.795-800
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    • 2008
  • The sound transmission loss is a key index to evaluate the acoustic performance of a car-body structure at the high frequency range. From this paper, a new validation method for in-situ sound transmission loss is proposed. First, in-situ sound transmission loss is measured by using PU intensity probe on the condition of complete vehicle. Second, validation test, which is consisted of internal, external and total frequency response function test, is performed by using volume acceleration source and microphones. Then, these test results are compared to validate the accuracy of in-situ sound transmission loss. Finally, the test result of in-site method is compared with results of two reverberant room test method and SEA analytical method. The reliability of in-situ method is confirmed by these procedures.

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