• Title/Summary/Keyword: Transition zone

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Dynamic Behavior on Transition Zone of the Railway Bridge-earthwork by Shape of Transition Zone (구조물 접속부 형상에 따른 철도 교량-토공 접속부의 동적거동)

  • Jung, Kwangsu;Ahn, Kwangkuk;Kang, Hongsig
    • Journal of the Korean GEO-environmental Society
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    • v.22 no.4
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    • pp.5-13
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    • 2021
  • The transition is the zone where support stiffness suddenly increases in the railway industry. If the support stiffness increases, differential settlement will occur at the transition due to difference of stiffness, and the differential settlement causes problems for the train running safety and the roadbed that supports the track. In particular, a study on differential settlement at bridge-earthwork transition was only conducted to considering railway load in most cases. However, these studies have not taken account of earthquake despite earthquake has been occurred frequently in the recent, and it is necessary to consider earthquake. Therefore, in this study numerical analysis has been performed by changing the inclination of approach block, which determines the shape of the transition, and earthwork in order to verify the effect of the shape of the transition on the dynamic behavior at the bridge-earthwork transition. The result shows that the dynamic behavior at the bridge-earthwork transition was affected by the shape of transition.

Evaluation of the heat island in transition zone of three cities in Kyungpook, Korea (추이대(推移帶)를 중심으로 한 경상북도 3개 도시의 열섬 평가)

  • Park, In Hwan;Jang, Gab Sue;Kim, Jong Yong
    • Journal of Environmental Impact Assessment
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    • v.8 no.2
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    • pp.73-82
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    • 1999
  • This study analyzed the relationship between NDVI(Normalized Difference Vegetation Index) and urban heat island in three cities: Daegu, Kyungju, and Pohang for understanding the degree of nature conservation concentrating in the transition zone of them. Daegu city is the third city in Korea which has a dense population. Kyungju is a traditional city which has good nature. Pohang is an industrial city which has those of characters of Daegu and Kyungju. Landsat 1M data in May 17, 1997 were used for the analysis of heat island. There were about four theoretical models to estimate the surface temperature from TM data: Two-point linear model, Linear regression model, Quadratic regression model, and Cubic regression model. In this study, Linear regression model had been utilized to analyze the urban heat island. On the resultant images, the transition zone of Daegu was urbanized more extremely than those of other two cities. It is thought that the analysis of relationship between NDVI and surface temperature, used in this study, is regarded as one of effective methodologies for urban-environmental detection from satellite imageries.

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Assessing Distribution of Degree of Saturation for Track Transition Zone Using Soil Water Characteristic Curve (접속부 궤도 성토재료의 함수특성곡선을 이용한 포화도 분포 산정)

  • Choi, Chanyong;Lee, Jungmin;Kwon, Hyeok Min;Oh, Jeongho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.2
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    • pp.515-524
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    • 2015
  • The number of occurrence of differential settlement and track irregularity at track transition zone recently comes to increase, which leads to frequent maintenance activities that have an impact on train operation. Such track transition zone damages are attributed to the change of mechanical properties of fill materials due to environmental factors such as rainfall and freeze, and thaw. Consequently, this study attempts to establish the soil water characteristic curve (SWCC) of fill materials, and conduct seepage analysis to assess the distribution of degree of saturation (DOS) for track transition zone in case of rainfall. The SWCC of fill materials was successfully obtained using filter paper test method. The results of seepage analysis revealed that rainfall intensity, the slope of backfill, backfill condition (fill or cut), and SWCC are significantly influential in controlling the distribution of DOS.

Investigation on the Characteristics of Interfacial Transition Zone (ITZ) of High-Strength Cement Mortar Incorporating Graphene Oxide (그래핀 옥사이드 혼입 고강도 시멘트 모르타르의 Interfacial Transition Zone (ITZ) 특성에 관한 연구)

  • Im, Su-Min;Cho, Seong-Min;Liu, Jun-Xing;Lim, Seungmin;Bae, Sung-Chul
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.10 no.3
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    • pp.343-350
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    • 2022
  • In recent years, nanomaterials, such as nano-silica, carbon nanotubes, and graphene oxide (GO), have been suggested to improve the properties of the interfacial transition zone (ITZ) between aggregates and cement pastes, which has most adversely affected the strength of quasi-brittle concrete. Among the nanomaterials, GO with superior dispersibility has been reported to be effective in improving the properties of ITZ of normal-strength concrete by forming interfacial chemical bonds with Ca2+ ions abundant in ITZ. In this study, the effect of GO on the properties of ITZ in the high-strength mortar was elucidated by calculating the change in hydration heat release, ITZ thickness, and the porosity around ISO sand, which was obtained with isothermal calorimetry tests and scanning electron microscope image analysis, respectively.

Response Analysis of Ground Vibration for Cutting and Embankment Transition Zone Structure (절성토 접속구조별 지반진동 응답특성)

  • Lee, Il-Wha;Yun, Won-Min;Choi, Won-Il;Hwang, In-Hwan;Hwang, Sung-Wook
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.3195-3200
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    • 2011
  • The vibration resulting from railway operation is transmitted through the track and line structure, ground movements to adjacent buildings. As these vibration is growing, there is occurred exaggerated forces and displacements of the track and line structure and it is causing the differential settlement. It is difficult to clarify the dynamic response characteristics of trackbed because of various environmental conditions. However, track irregularity be affected by ununiformed bearing capacity and its dynamic response, study for dynamic response characteristics is required to investigate the cause of track irregularity and countermeasure. This study was intended to evaluate the numerical analysis which exam the response analysis characteristic of ground vibration by shape of cutting and embankment transition zone. The original method of analysis were have to examine variables such as directions, angles, drain conditions, linear conditions. However, In the analysis there were to consider the effect of moving loads according to directions of cutting and embankment transition zone.

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The Ciliary Transition Zone: Finding the Pieces and Assembling the Gate

  • Goncalves, Joao;Pelletier, Laurence
    • Molecules and Cells
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    • v.40 no.4
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    • pp.243-253
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    • 2017
  • Eukaryotic cilia are organelles that project from the surface of cells to fulfill motility and sensory functions. In vertebrates, the functions of both motile and immotile cilia are critical for embryonic development and adult tissue homeostasis. Importantly, a multitude of human diseases is caused by abnormal cilia biogenesis and functions which rely on the compartmentalization of the cilium and the maintenance of its protein composition. The transition zone (TZ) is a specialized ciliary domain present at the base of the cilium and is part of a gate that controls protein entry and exit from this organelle. The relevance of the TZ is highlighted by the fact that several of its components are coded by ciliopathy genes. Here we review recent developments in the study of TZ proteomes, the mapping of individual components to the TZ structure and the establishment of the TZ as a lipid gate.

A Study on Characteristic of Super-Tall Mixed-Use Residential Building in the Outdoor Transition Zone (초고층 주거복합건물의 기단부 계획특성 분석에 관한 연구)

  • Kim, Kyoung min;Je, Hae seong
    • KIEAE Journal
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    • v.7 no.4
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    • pp.75-80
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    • 2007
  • The purpose of this study is to analyze architectural plans of lower part of super tall mixed-use residential building for understanding its functions for urban. The area of this research are limited to super tall mixed-use residential building which were built in Seoul, Kyoung-gi area, and new towns. For this purpose, theories for super tall mixed-use residential building and non-housing parts were researched, and characteristics of selected cases for field research were analyzed by studying drawing materials. The research focused on scale, type of building, included programs for public spaces, and characteristics of location. As a result, every cases were designed as 'outdoor transition zone-centered type', and for urban function, non-housing facilities were condensed to increase convenience. In addition, ratio of non-housing part were incresesed with public spaces design for residents, and various programs were inserted.

Predicting Model for Pore Structure of Concrete Including Interface Transition Zone between Aggregate and Cement Paste

  • Pang, Gi-Sung;Chae, Sung-Tae;Chang, Sung-Pil
    • International Journal of Concrete Structures and Materials
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    • v.3 no.2
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    • pp.81-90
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    • 2009
  • This paper proposes a semi analytical model to describe the pore structure of concrete by a set of simple equations. The relationship between the porosity and the microstructure of concrete has been considered when constructing the analytical model. The microstructure includes the interface transition zone (ITZ) between aggregates and cement paste. The predicting model of porosity was developed with considering the ITZ for various mixing of mortar and concrete. The proposed model is validated by the rapid experimental programs. Although the proposed model is semi-analytical and relatively simple, this model could be reasonably utilized for the durability design and adapted for predicting the service life of concrete structures.

Water Quality Modeling of the Eutrophic Transition Zone in a River-Type Reservoir Paldang (부영양화된 하천형 호소(팔당호) 전이대의 수질모델링)

  • Kong, Dongsoo
    • Journal of Korean Society on Water Environment
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    • v.30 no.4
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    • pp.429-440
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    • 2014
  • This study was conducted to investigate the main cause of water quality deterioration during the spring season in the transition zone between the South Han River and the river-reservoir Paldang. A water quality model modified from QUAL2E (U.S.EPA) was used, and the model showed that eutrophication and algal production in the low flow season affected about 60% of the organic pollution at the downstream of the South Han River. This result means that phosphorus control is prior to external organic material management to ameliorate the deterioration of water quality in the water body.