• Title/Summary/Keyword: 환경 거동

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The Study on the Wear Corrosion Behavior of Induction Hardening High Strength Cast Iron in the pH Environments (고주파 열처리한 강인주철재의 마멸부식거동에 관한 연구)

  • Park, Yun-Sik;Lim, Uh-Joh;Park, Dong-Gi
    • Journal of the Korean Institute of Gas
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    • v.12 no.4
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    • pp.52-57
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    • 2008
  • This paper studies on the wear corrosion behavior of induction hardening high strength cast iron in the acidic environments. In a variety of pH solutions, wear corrosion behavior of GC 300 with a variety of contact pressures was investigated, and corrosion wear behavior after immersion test was considered. Also, electrochemical polarization test for GC 300 was carried out in various pH solutions. The main results are as following: In the strong acidic environment, wear corrosion rate of GC 300 appears highly and in the neutral environment is stable. Also, graphitic corrosion in the strong acidic environment occurs. The corrosion current density of GC 300 becomes high in a order of pH 1 > pH 2 > pH 4 > pH 6.5.

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A study for Variation of Consolidation Behavior by Analysis Method (해석기법에 따른 압밀거동 변화에 관한 연구)

  • Chung, Youn-In;Kim, Min-Jung
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.17 no.2
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    • pp.97-103
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    • 2011
  • In this study, finite element analysis is performed for consolidation behavior prediction of drainage-installed soft deposits. Finite element analysis is performed under the two strain conditions as small strain with limited application and large strain for relatively thick layers, large deformation and non-linear material properties. The analysis conditions such as layer depth, loading conditions, smear effects are also changed and variation of consolidation behavior for each condition is estimated from ABAQUS program.

Unconfined Compressive Stress-Strain Behavior of Cemented Granular Geomaterials (강화된 입상지반재료의 일축압축 응력-변형거동)

  • Park, Seong-Wan;Cho, Chung Yeon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5C
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    • pp.183-190
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    • 2009
  • It is necessary to predict the deformation and stresses on soils to establish the nonlinear stress-strain relationship of geomaterials at various strain levels. Especially, a need exists to establish the pre-failure nonlinear characteristic of cemented granular geomaterials used in road constructions. In this paper, therefore, conventional granular soils were mixed with various cementing materials, such as cement and fly ash from coal combustion by-products. Then, the normalized nonlinear behavior of cemented geomaterials was assessed using unconfined compression test. In addition, various constitutive models of soils were evaluated for estimating pre-failure non-linear behavior of cemented geomaterials from the test results.

Numerical Model for the Estimation of Ultimate Load Capacity of CFT Columns Considering Time-dependent Behavior (시간 의존적 거동을 고려한 CFT 기둥의 극한 하중 계산을 위한 수치 해석 모델 제안)

  • Seong Hun Kim;Hyo-Gyoung Kwak
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.37 no.1
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    • pp.25-31
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    • 2024
  • This paper introduces a numerical analysis model capable of evaluating CFT (Concrete-Filled Tube) columns across all time stages, incorporating creep behavior analysis and inelastic analysis to account for time-dependent behavior. The proposed model is compared with experimental results, revealing that the numerical model presented in this paper demonstrates more accurate trends than existing design criteria. Following verification, a numerical analysis is conducted for each slenderness ratio, determining the ultimate load capacity and examining the short-term and long-term sustained load behavior of the overall CFT column members.

Fate and Transport of Viruses in Soil and Groundwater Environments (토양.지하수 환경에서 바이러스의 거동)

  • Park, Jeong-Ahn;Yoon, Seo-Young;Kim, Song-Bae
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.7
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    • pp.504-515
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    • 2012
  • Groundwater is widely used as drinking water supplies around the world. However, microbial contamination of groundwater is a serious environmental problem that degrades drinking water quality and poses a great threat to human health. Among the pathogenic microorganisms such as viruses, bacteria, and protozoa, viruses are not readily removed during transport through soils, having high mobility in groundwater environment due to their smaller size compared to bacteria and protozoa. Studies regarding the fate and transport of viruses in soils and aquifers are necessary to determine the vulnerability of groundwater to microbial contamination and to secure safe drinking water sources. Also, these studies provide important information to establish the regulations and policies related to public health. This review paper presented the field and laboratory studies conducted for the fate and transport of viruses in subsurface environments. Also, the paper provided the factors affecting the fate and transport of viruses, the characteristics of bacteriophages used for virus studies, and virus transport model/colloid filtration theory. Based on this review work, future researches should be performed actively to set up the viral protection zone for the protection of groundwater from viral contamination sources. Especially, the researches should be focused on the development of mathematical models to calculate the setback distance and travel time for the viral protection zone along with the accumulation of information related to the model parameters.