• Title/Summary/Keyword: well 저항

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An Electrical Resistivity Survey for Leachate Investigation at a Solid Waste Landfill (폐기물 매립지 침출수 조사를 위한 전기비저항 탐사)

  • Lee, Keun-Soo;Cho, In-Ky;Mok, Jong-Koo;Kim, Jeong-Woo
    • Geophysics and Geophysical Exploration
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    • v.19 no.2
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    • pp.59-66
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    • 2016
  • The electrical resistivity method is an effective geophysical tool to detect subsurface contamination because the contaminated zones show generally lower electrical resistivity. In this study, the electrical resistivity surveys were applied to a waste landfill site to image the subsurface structure around the landfill and to identify the contaminated zones. First, the dipole-dipole 2D resistivity surveys were conducted along the boundaries of landfill to define the developed contaminated zones. Then the crosshole resistivity tomography was applied to confirm the suspected contaminated zones at depth. The results of drilling and geochemical analysis of ground water supported that the low resistivity zones coincide well with the contaminated zones and the leachate pathways could be delineated effectively from the resistivity survey.

Occurrence and antibiotic resistance of Enterococcus spp. from retail fresh-cut products in Korea (국내 신선 편이식품으로부터 분리한 Enterococcus의 항생제 저항성)

  • Kim, Hyun Jung;Kim, Seung Min
    • Korean Journal of Food Science and Technology
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    • v.50 no.6
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    • pp.581-586
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    • 2018
  • Enterococcus spp. have been considered major indicator organisms for antibiotic resistance due to their ability to easily acquire and to harbor antibiotic resistance. In this study, Enterococcus spp. were isolated from 174 retail fresh-cut products (fresh vegetable salads, microgreens, and sprouts) in Korea. Among the 20 Enterococcus isolates obtained, 18 (90.0%) were Enterococcus faecalis and 2 (10.0%) were Enterococcus faecium. The patterns of antibiotic resistance against nine antimicrobials were analyzed. Most of the isolates (85.0%) were resistant to quinupristin/dalfopristin, 40.0% and 50.0% of the isolates showed intermediate resistance to two critically important antimicrobials for human medicine, ciprofloxacin and erythromycin, respectively. Vancomycin-resistant enterococci were not detected in this study. Given the importance of antimicrobial resistance of enterococci in food safety as well as in public health, our results regarding the occurrence (level of contamination) and antimicrobial resistance of Enterococcus spp. could provide useful information that aids the risk analysis of antibiotic resistance.

Evaluating the Durability of Concrete Combined with Ground Granulated Blast Furnace Slag using Electrolysis Alkaline Aqueous as Mixing Water (전기분해 알칼리수를 배합수로 사용한 고로슬래그 미분말 혼입 콘크리트의 내구성)

  • Jeong, Su-Mi;Kim, Ju-Sung;Park, Sun-Gyu
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.4
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    • pp.349-358
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    • 2023
  • This research aimed to enhance the initial strength of concrete that is mixed with ground granulated blast furnace slag, as well as to fortify its resistance to carbonation and chloride ion permeation. To achieve this, alkaline aqueous, produced through the electrolysis of potassium carbonate, was employed as the mixing water in the preparation of concrete. To substantiate the increment in initial strength, compressive strength measurements of the concrete were executed. Additionally, an accelerated carbonation test and a chloride ion permeation resistance test were undertaken. The results confirmed that the initial strength of the concrete, which utilized electrolysis alkaline aqueous as mixing water, exhibited an improvement in comparison to concrete mixed with conventional water. It was also verified that both carbonation resistance and chloride ion permeation resistance showed enhancements.

Inelastic Dynamic Demands of a RC Special Moment Frame Building (철근 콘크리트 특수 모멘트 골조 건물의 비탄성 동적 요구값)

  • Kim, Tae-Wan
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.5 s.45
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    • pp.11-19
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    • 2005
  • Seismic design of a building is usually performed by using the linear static procedure. However, the actual behavior of the building subjected to earthquake is inelastic and dynamic in nature. Therefore, inelastic dynamic analysis is required to evaluate the safety of the structure designed by the current design codes. For the validation, a RC special moment resisting frame building was chosen and designed by IBC 2003 representing new codes. Maximum plastic rotation and dissipated energy of some selected members were calculated for examining if the inelastic behavior of the building follows the intention of the code, and drift demand were calculated as well for checking if the building well satisfies the design drift limit. In addition, the effect of including internal moment resisting frames (non lateral resisting system) on analyses results was investigated. As a result of this study, the building designed by IBC 2003 showed the inelastic behavior intended in the code and satisfied the design drift limit. Furthermore, the internal moment resisting frames should be included in the analytical model as they affect the results of seismic analyses significantly.

Effectiveness of the Electrode Arrays for Delineating 2-D Subsurface Structure (2차원 지하구조 규명을 위한 전극배열의 효율성)

  • Yoon, Jong-Ryeol;Lee, Kiehwa
    • Economic and Environmental Geology
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    • v.29 no.3
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    • pp.345-355
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    • 1996
  • The effectiveness of various electrode configurations in horizontal mappings and 1-D inversions of vertical sounding data for delineating 2-D structures was studied. Apparent resistivity values of three point, dipole-dipole, Wenner, and Schlumberger mappings were simulated for such structures as vertical dyke, tabular prism, buried vertical fault, ramp and complex structure by finite difference method (FDM) and they were compared with each other. Also 2-D cross sections for three structures obtained by interpolation of 1-D inverted sounding data in terms of three layers were compared for Schlumberger and Wenner arrays. On these cross sections, horizontal and vertical resistivity interfaces of the 2-D structures are revealed relatively clearly. Apparent resistivity curves of Schlumberger mapping show vertical resistivity discontinuities very well. On the whole, Schlumberger array is superior to the other arrays in electric sounding as well as mapping. This study clearly indicates that interpretations of 2-D structures based on 1-D inversion are possible.

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Evaluation of Rutting and Deformation Strength Properties of Polymer Modified SMA Mixtures (개질재 첨가에 따른 SMA 혼합물의 소성변형 및 변형강도 특성 연구)

  • Kim, Hyun-H.;Choi, Young-R.;Kim, Kwang-W.;Doh, Young-S.
    • International Journal of Highway Engineering
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    • v.11 no.4
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    • pp.25-31
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    • 2009
  • In general, it is well known fact that the stone mastic asphalt (SMA) pavement has a high resistance against rutting. However, performance of SMA is not well measured by general method used in the laboratory. The objective of this study is to investigate an applicability of deformation strength ($S_D$) for performance estimation of SMA, and to find out the correlation between rut depth and dynamic stability, and $S_D$ of SMA. This study carried out wheel tracking test and Kim-test with optimum asphalt content (OAC) determined by mix design. The results indicated that the $S_D$ of SMA was very poorer than those of dense-graded asphalt mixtures. $S_D$ showed similar WT dynamic stability and rut-depth level. It was found that Kim-test was not reflected higher rutting resistance of SMA like as indirect tensile strength (ITS) test and Marshall stability test. Also, it was revealed that dynamic stability and rut-depth of WT had some problems to estimate rutting resistance of SMA mixtures.

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Design of Vortical Drain in consideration of Smear Effect and well Resistance (교란효과와 배수저항을 고러한 연직 배수재의 설계)

  • 김태우;강예묵;이달원
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1998.10a
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    • pp.438-443
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    • 1998
  • In this study, compared the degree of consoildation of vertical drain considering variation of smear effect and well resistance with that of hyperbolic and curve fitting method. It applied Barren, Yoshikuni, Hansbo, Onoue's theory for the consolidation of vertical drain, and compared differences of theoretical curve by comparing with measured value, and finded out the extent of smear effect and well resistance.

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Studies of Insecticide Resistance in Green Peach Aphids, Myzus persicae(Sulz) III. Acephate Resistance, Cross-Resistance, and Esterase Isozymes (복숭아혹진딧물의 살충제 저항성(抵抗性)에 관한 연구(硏究) III. Acephate저항성(抵抗性) 발달(發達), 교차저항성(交叉抵抗性) 및 Esterase Isozymes)

  • Choi, Seung-Yoon;Kim, Gil-Hah
    • Korean journal of applied entomology
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    • v.25 no.2 s.67
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    • pp.99-105
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    • 1986
  • The green peach aphids(Myzus persicae) collected in a field had been successively selected by acephate(O, S-dimethyl N-acetyl phosphoroamidothioate) in the laboratory. The selected aphid strain in the 20th generation demonstrated relatively high resistance to acephate as well as relatively high cross-resistance to cypermethrin and oxydemeton-methyl, except pirimicarb. The different esterase isozymes with the strains were detected by the agarose gel electrophoresis and among the isozymes the band of ${\beta}-2$ was only specific for the acephate resistant strains.

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Integrated Interpretation of ERT Data from the Mineralized Zone in Geumpung Mine (금풍광산 광화대에 대한 전기비저항 토모그래피탐사 자료의 복합해석)

  • Jung, Yeon-Ho;Byun, Joong-Moo
    • Geophysics and Geophysical Exploration
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    • v.10 no.4
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    • pp.322-331
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    • 2007
  • In this study, electrical resistivity tomography (ERT) were conducted to find the mineralized zone at the Geumpung mine in Dojeon-ri, Susan-myeon, Jecheon-si, Chungcheongbuk-do. The deviation of the inclined borehole was measured to obtain the exact positions of the electrodes for correcting apparent resistivity values from ERT. Geophysical loggings such as resistivity and natural gamma were conducted to obtain the properties of the material near the borehole. Measurements of the physical properties of the cores, such as porosity, water content, density, susceptibility, resistivity were performed to analyze the correlation between physical properties and resistivity. Grade analysis for core sample was also conducted to identify relationship between grade and resistivity. Rock property analysis shows that the resistivity is more dominated by susceptibility and grade than by porosity and water content in the mineralized zone. The results of ERT are well consistent with geophysical logging data and geologic column. So ERT is powerful method to identify conductive mineralized zone.

Study on the Removal Efficiency of a TEDA Impregnated Charcoal Bed for Methyliodide under Dry Condition (건조 조건하에서 TEDA주입 탄소층에 의한 Methyliodide 제거 효율에 관한 연구)

  • Won Jim Cho;Soon Heung Chang
    • Nuclear Engineering and Technology
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    • v.16 no.2
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    • pp.80-88
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    • 1984
  • The removal mechanism of air borne methyl iodide by triethylenediamine (TEDA) impregnated charcoal bed was investigated. The analysis of experimental data indicates that pore diffusion is the rate controlling step when the air velocity is over 20cm/sec, and both fore diffusion resistance and external mass transfer resistance are contributed to the overall resistance when the air velocity is 10cm/sec. The adsorption model to describe the performance of impregnated charcoal bed under dry condition where water vapors do not exist in air, is proposed. The calculated values and experimental results are well matched.

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