• Title/Summary/Keyword: 내단열

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조경수 용기재배 시 지온 안정화를 위한 용기의 디자인개발

  • Jeong, Jun-Rae;Choe, Ji-Hye;Jeong, Yun-Seop;Choe, Dong-Hun;Gwon, Yeong-Hyu
    • Proceedings of the Korean Institute of Landscape Architecture Conference
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    • 2017.10a
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    • pp.147-149
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    • 2017
  • 경수 용기재배는 뿌리분의 손상 없이 식재를 할 수 있어 이식 후 활착이 용이하고, 식재시기의 계절적 제약을 적게 받아 부적기 이식 시 하자를 현저히 줄일 수 있다. 용기재배 시 용기 내 토양온도는 토양의 물리화학반응과 식물의 생육 및 물과 양분의 흡수에 영향을 주는 중요한 토양환경요소의 하나이다. 목본성 식물 용기재배의 경우 제한된 근권부의 토양이 외부기온에 의해 불안정할 수 밖에 없다. 재배용기의 유형에 따른 지온의 변화를 측정한 결과 지중재배형의 용기가 단열성능이 큰 것으로 나타났다. 지상재배 방식의 용기 중에서는 Bag in Pot-루트 스커트 형의 용기가 단열성능이 큰 것으로 나타났으며, 이는 지중재배방식의 용기와 유사한 용기 내 지온 안정화 정도를 보이는 것으로 나타났다. 향후 후속 연구에서는 본 연구를 토대로 디자인 개발된 용기의 시제품을 제작하여 테스트하고, 재배농가에 적용가능성을 검토하고자 한다.

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Hydrogeological properties around the KURT (KURT 주변지역의 수리지질특성 연구)

  • Lee, Jin-Yong;Kim, Kyung-Su;Park, Kyung-Woo;Han, Woon-Woo
    • The Journal of Engineering Geology
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    • v.20 no.2
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    • pp.121-126
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    • 2010
  • Current technology for radioactive waste disposal facility is operated as part of KURT site characterization in terms of reliability assessment is conducted to expand. In this study, a geological model of KURT surrounding area on the basis of flow characteristics of the site-scale hydrogeological study was about. Distributed in the study area into four boreholes were plotted using the stereo net NS, NW, EW, Low-angle fracture group was able to identify the components of geological models and include top soil layer, belt of weathering, Low-angle fracture zone, fracture zone was divided into. Separated by fracture of the hydraulic test of through the groundwater aquifer that provides the flow hydraulic conductivity and insulation hydraulic affecting the slope of the normal distribution for the size and direction by performing statistical analysis of fracture in the direction of local ns The advantage was confirmed. In addition, Low-angle fracture hydraulic conductivity of the value of 3.61e-07 m/s has a value greater than the major fracture, the fracture zones exist in the base rock and base rock and the hydraulic characteristics of the different methods applied and had to have a different interpretation judged by was.

Size Effect of Hollow Silica Nanoparticles as Paint Additives for Thermal Insulation (단열 페인트 첨가제로써 중공형 실리카 나노입자의 크기에 따른 효과)

  • Kim, Jisue;Kim, Younghun
    • Clean Technology
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    • v.28 no.1
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    • pp.18-23
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    • 2022
  • Using air as an insulator due to its low heat transfer coefficient has been studied and has been widely commercialized to save energy in the field of thermal insulation technology. In this study, we analyzed the heat insulating effect of hollow silica nanoparticles mixed in non-uniform size, and the maximum heat insulating efficiency of these particles given the limited number of particles that can be mixed with a medium such as paint. The hollow silica nanoparticles were synthesized via a sol-gel process using a polystyrene template in order to produce an air layer inside of the particles. After synthesis, the particles were analyzed for their insulation effect according to the size of the air layer by adding 5 wt % of the particles to paint and investigating the thermal insulation performance by a heat transfer experiment. When mixing the particles with white paint, the insulation efficiency was 15% or higher. Furthermore, the large particles, which had a large internal air layer, showed a 5% higher insulation performance than the small particles. By observing the difference in the insulation effect according to the internal air layer size of hollow silica nanoparticles, this research suggests that when using hollow particles as a paint additive, the particle size needs to be considered in order to maximize the air layer in the paint.

Potential repository domain for A-KRS at KURT facility site (KURT 부지 조건에서 A-KRS 입지 영역 도출)

  • Kim, Kyung-Su;Park, Kyung-Woo;Kim, Geon-Young;Choi, Heui-Joo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.10 no.3
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    • pp.151-159
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    • 2012
  • The potential repository domains for A-KRS (Advanced Korean Reference Disposal System for High Level Wastes) in geological characteristics of KURT (KAERI Underground Research Tunnel) facility site were proposed to develop a repository system design and to perform the safety assessment. The host rock of KURT facility site is one of major Mesozoic plutonic rocks in Korean peninsula, two-mica granite, which was influenced by hydrothermal alteration. The topographical features control the flow lines of surface and groundwater toward south-easterly and all waters discharge to Geum River. Fracture zones distributed in study site are classified into order 2 magnitude and their dominant orientations are N-S and E-W strike. From the geological features and fracture zones, the potential repository domains for A-KRS were determined spatially based on the following conditions: (1) fracture zone must not cross the repository; and (2) the repository must stay away from the fracture zones greater than 50 m. The western region of the fracture zones in the N-S direction with a depth below 200 m from the surface was sufficient for A-KRS repository. Because most of the fracture zones in N-S direction were inclined toward the east, we expected to find a homogeneous rock mass in the western region rather than in the eastern region. The lower left domain of potential domains has more suitable geological and hydrogeological conditions for A-KRS repository.

A Computer Programme Development for Thermal-Hydraulic Analysis and Optimal Design on LNG Pipeline System (LMG 배관시스템의 열유동 해석 및 최적설계 프로그램 개발)

  • Lee Sanggyu;Hong Seong-Ho;Lee Joong-Nam;Park Seok-Ho
    • Journal of the Korean Institute of Gas
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    • v.4 no.2 s.10
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    • pp.7-14
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    • 2000
  • LNG (Liquified Natural Gas) carried by LNG ship is unloaded into the LNG storage tanks at the very low temperature (a little lower than the boiling point of LNG). Because LNG is unloaded through the pipeline, two phase flow appears in the pipeline. In this study, we have studied the pressure-drop mechanisms of the two-phase flow in the pipeline, and the calculation method of BOG (Boil-off Gas) amount based on the heat transfer mechanism through the insulation and the surface of the pipeline. We have developed a computer program for thermal-hydraulic analysis on the LNG pipeline system. We have also developed the optimal design program to find the optimal thickness of insulation and the pipeline size. The program searches the optimal design with the minimum capital cost of pipelines and insulation on the operating conditions of maximum allowance pressure-drop and BOG amount, etc.

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Effects of Corrugated GFRP Shear Connector Width and Pitch on In-plane Shear Behavior of Insulated Concrete Sandwich Wall Panels (CSWP) (파형 GFRP 전단연결재의 폭 및 너비에 따른 중단열 벽체의 면내전단거동)

  • Jang, Seok-Joon;Oh, Tae-Sik;You, Young-Chan;Kim, Ho-Royng;Yun, Hyun-Do
    • Journal of the Korea Concrete Institute
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    • v.26 no.4
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    • pp.421-428
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    • 2014
  • This paper describes the experimental results of insulated concrete sandwich wall panels (CSWP) with corrugated glass fiber-reinforced polymer (GFRP) shear connectors under in-plane shear loading. Corrugated GFRP shear connectors were used to improve the thermal property of insulated CSWP and to achieve composite action between the interior and exterior concrete wall panels. Test specimens were consist of three concrete panels with two insulation layers between concrete panels and middle concrete panels was loaded in the direction of gravity. To evaluate the effects of insulation types (extruded polystyrene, XPSS and expanded polystyrene, EPS), shear connector pitch (300 and 400 mm) and width (10 and 15 mm) on in-plane shear behavior of insulted CSWP, failure mode and shear flow-average relative slip relationship of specimens were investigated. Test results indicate that the bond stress between concrete panel and insulation is considerable initially. Especially in case of insulated CSWP without shear connector, initial stiffness of CSWP with XPSS is superior to that of CSWP with EPS. The shear connector's contribution to in-plane shear performance of insulated CSWP depends on the type of insulation.

In Situ Solute Migration Experiments in Fractured Rock at KURT: Installation of Experimental System and In Situ Solute Migration Experiments (KURT 암반 단열에서 현장 용질이동 실험: 실험 장치 설치 및 현장 용질 이동 실험)

  • Lee, Jae-Kwang;Baik, Min-Hoon;Lee, Tae-Yeop;Park, Kyung-Woo;Jeong, Jongtae
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.11 no.3
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    • pp.229-243
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    • 2013
  • An in situ solute migration system was designed and installed in KAERI Underground Research Tunnel (KURT) constructed in the site of Korea Atomic Energy Research Institute (KAERI) in order to investigate the migration and retardation of non-sorbing and sorbing tracers through a rock fracture. The system is composed of three main parts including injection, extraction, and data treatment. For the selection of a water-conducting fracture, boreholes were drilled. The fractures in the drilled boreholes were investigated using borehole image analysis using borehole image processing system (BIPS). The results of BIPS analysis showed that borehole YH 3-1 and YH 3-2 were connected each other. Moreover, hydraulic tests were carried out to determine the test section with connectivity for the in situ experiments. The in situ solute migration experiments were accomplished to understand the migration of solutes through fractures in KURT using non-sorbing tracers which were fluorescein sodium, eosin-B, bromide and sorbing tracers which were rubidium, nickel, zirconium, and samarium.

Interpretation of Deformation History and Paleostress Based on Fracture Analysis Exposed in a Trench (트렌치에서의 단열분석을 통해 도출한 단열발달사 및 고응력 해석: 울산 신암리의 예)

  • Gwon, Sehyeon;Kim, Young-Seog
    • The Journal of Engineering Geology
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    • v.26 no.1
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    • pp.33-49
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    • 2016
  • The study area, located in Sinam-ri, Ulsan, in the southeastern part of the Korean Peninsula, is mainly composed of hornblende granite (ca. 65 Ma). Fracturing and reactivation of a fault striking ENE-WSW was strongly controlled by the intrusion of a mafic dyke (ca. 44 Ma), which behaves as a discontinuity in the mechanically homogeneous pluton, increasing the instability of the basement in this area. A geometric and kinematic study undertaken to interpret the faults and fractures was performed in a trench excavated almost perpendicular to the orientation of the dyke. The analysis of structural elements, such as dykes, veins, and faults, is used to infer the deformation history and to determine the paleostress orientations at the time of formation of the structures. The deformation history established based on this analysis is as follows: (1) NNE-SSW, E-W, ENE-WSW, and NE-SW trending fractures had already developed in the pluton before dyke intrusion; (2) felsic dykes intruded under conditions of σHmax oriented N-S and σHmin oriented E-W; (3) mafic dykes intruded under conditions of σHmax oriented E-W and σHmin oriented N-S; (4) dextral reactivation of the main fault associated with the development of hydrothermal quartz veins under conditions of σHmax oriented E-W and σHmin oriented N-S; (5) sinistral reactivation of the main fault and high-angle normal faults under conditions of σHmax oriented NE-SW and σHmin oriented NW-SE; and (6) dextral reactivation of the main fault and NE-SW low-angle reverse faults under conditions of σHmax oriented NW-SE and σHmin oriented NE-SW. These results are consistent with the tectonic history of the Pohang-Ulsan block in the southeastern part of the Korean Peninsula, and indicates the tectonic deformation of the southern area of the Ulsan fault bounded by Yangsan fault was analogous to that of the Pohang-Ulsan area from the Cenozoic. This work greatly aids the selection of sites for critical facilities to prevent potential earthquake hazards in this area.