• Title/Summary/Keyword: environmental test

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The Relationship between Children's Reading Ability of Environmental Print, Vocabulary and Print Concepts (유아의 환경인쇄물 읽기능력과 어휘력 및 인쇄물 개념 간의 관계)

  • Lee, Shin Hee;Kim, Myung Soon;Son, Seung Hee
    • Korean Journal of Child Studies
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    • v.34 no.3
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    • pp.75-92
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    • 2013
  • This study investigated the differences and relationships between environmental print reading ability, vocabulary, and print concepts of children at ages 3 and 4. The subjects comprised 90 children, who could not read letters. The Children's Reading Ability of Environmental Print Scale(Son, 2012), Receptive and Expressive Vocabulary Test(Kim et al., 2009) and Concepts About Print(Kim & Kim, 2004) were used in this study. The collected data were analyzed using t-test and Pearson's correlations. The results of this study were as follows; in terms of Illiterate Korean children, aged 3 to 4 years, their scores on the environmental print reading tasks were positively correlated with vocabulary and print concepts.

Phenotypic characteristics and antimicrobial susceptibility of verotoxin -producing E coli from slaughtered cattle

  • Byun Jae-Won;Kim Kyoung-Ho;Lee Sung-Mo;Hwang Hyun-Soon;Kim Yong-Hee
    • Korean Journal of Veterinary Service
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    • v.28 no.4
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    • pp.407-412
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    • 2005
  • Ten isolates of Verotoxin-producing Escherichia coli (VTEC) were detected in slaughtered cattle and investigated their phenotypic characteristics and antimicrobial susceptibility. None of the isolates was positive for eae gene. Only one isolate was positive for uidA gene. Eight out of ten isolates of VTEC were originated from broker's cattle. Thus microbiological monitoring for broker farms should be performed to minimize VTEC contamination. In the antimicrobial susceptibility test, all the isolates were highly resistant to bacitracin and lincomycin whilst they are susceptible to apramycin and neomycin.

An Experimental Study on Strength Characteristics of Clay Mixed with Organic Acid Ground Improvement Material (유기산계 지반개량재를 혼합한 점토의 강도 특성에 관한 실험적 연구)

  • Im, Soyeong;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.8
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    • pp.5-9
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    • 2013
  • In this study, it was examined a strength characteristic of organic acid material that is eco-friendly and low energy as a soil improving material. The object of this study is to analysis of strength changes with observing the clay mixed organic acid material through the unconfined compression strength test and triaxial compression test during 28 days. As a result of the tests, the strength of clay mixed organic acid material is increased when the more ages are prolonged, the more organic acid material mixture ratio growed. Therefore, in grasping the strength improvement effects of clay by organic acid material mixing, it confirmed that organic acid material as soil improving material is effective through unconfined compression strength test and triaxial compression test. Through this test, the definite strength increase is confirmed according to the mixture of the organic acid material and the possibility of soil improvement is also confirmed based on this result. From now on, detailed examination and field test will help closely to definite strength characteristics.

Verification of Real-time Hybrid Test System using RC Pier Model (RC교각을 이용한 실시간 하이브리드 실험 시스템의 적용성 연구)

  • Lee, Jinhaeng;Park, Minseok;Chae, Yunbyeong;Kim, Chul-Young
    • Journal of the Earthquake Engineering Society of Korea
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    • v.22 no.4
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    • pp.253-259
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    • 2018
  • Structure behaviors resulting from an earthquake are experimentally simulated mainly through a shaking table test. As for large-scale structures, however, size effects over a miniature may make it difficult to assess actual behaviors properly. To address this problem, research on the hybrid simulation is being conducted actively. This method is to implement numerical analysis on framework members that affect the general behavior of the structure dominantly through an actual scale experiment and on the rest parts by applying the substructuring technique. However, existing studies on hybrid simulation focus mainly on Slow experimental methods, which are disadvantageous in that it is unable to assess behaviors close to the actual level if material properties change depending on the speed or the influence of inertial force is significant. The present study aims to establish a Real-time hybrid simulation system capable of excitation based on the actual time history and to verify its performance and applicability. The hybrid simulation system built up in this study utilizes the ATS Compensator system, CR integrator, etc. in order to make the target displacement the same with the measured displacement on the basis of MATLAB/Simulink. The target structure was a 2-span bridge and an RC pier to support it was produced as an experimental model in order for the shaking table test and Slow and Real-time hybrid simulations. Behaviors that result from the earthquake of El Centro were examined, and the results were analyzed comparatively. In comparison with the results of the shaking table test, the Real-time hybrid simulation produced more similar maximum displacement and vibration behaviors than the Slow hybrid simulation. Hence, it is thought that the Real-time hybrid simulation proposed in this study can be utilized usefully in seismic capacity assessment of structural systems such as RC pier that are highly non-linear and time-dependent.

The Evaluation of the Field Applicability of the Soil Improving Method Using the Environment-friendly Organic Acid Material (친환경 유기산 재료를 활용한 지반개량 공법의 현장 적용성 평가)

  • Lee, Jong-Hwi;Hong, Jong-Ouk;Jin, Youngguo;Chun, Byung-Sik
    • Journal of the Korean Geotechnical Society
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    • v.28 no.9
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    • pp.85-95
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    • 2012
  • The method of using organic acid is more environment-friendly for it improves the strength of the ground. The method of proliferating microbes makes soil particle bonded, finally improves the strength of the ground and decreasing permeability. Although there has been the research on the effect of strength increasing, there has never been a research on the evaluation of field application. In this paper, through the light drop weight test, the dynamic cone penetration test, the field density test, the variation of strength was investigated in the mixed ground with organic acid for 56 days. As the results of the field test, it was found that the strength and stiffness of the ground increased with organic acid, and that through SEM-EDS, the precipitation of calcium carbonate made by specified microbe obviously increased with organic acid material and so the ground was improved. Therefore, the sustainable development of this method needs to be analysed more in the future.