• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.143.2-143.2
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• 2011

Energy foundations and other thermo-active ground structure, energy wells, energy slab, and pavement heating and cooling represent an innovative technology that contributes to environmental protection and provides substantial long-term cost savings and minimized maintenance. This paper focuses on earth-contact concrete elements that are already required for structural reasons, but which simultaneously work as heat exchangers. Pipes, energy slabs, filled with a heat carrier fluid are installed under conventional structural elements, forming the primary circuit of a geothermal energy system. The natural ground temperature is used as a heat source in winter and heat sink in summer season. The system represented very high heating and cooling performance due to the stability of EWT from energy slab. Maximum heat pump unit COP and system COP were 4.9 and 4.3.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.48-53
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• 2003

원자력발전소로부터 발생하는 비가연성 고체폐기물의 모사시료에 대해 플라즈마 토치를 이용하여 고온용융처리 시험을 실시하였다 실험은 AP-200L 공동형 플라즈마토치를 사용하여 콘크리트, 흙과 금속이 포함되는 혼합물에 대하여 약 50시간 정도 수행되었다. 처리속도, 토치의 노즐과 용융물 표면과 간격, 토치 회전속도, 토치가스 유속 그리고 용융로의 압력 등 몇몇 실험조건을 사전에 결정하였으며, 냉각수 온도, 배가스 온도, 토치출력변화 등 기본 파라메타를 측정하였다. 유리화된 시료는 SEM/EDS로 분석하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 춘계학술논문 발표대회
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• pp.43-46
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• 2007

This study dealt with the influence of the replacement ratio of rapidly-chilled steel slag on fluidity and compressive strength of unsaturated polyester polymer concretes. The rapidly-chilled steel slag used in this study, a by-product which is produced by refining pig iron during the manufacture of steel, was controled by a air-jet method which rapidly cools substance melted at a high temperature. Experimental results show that fluidity and compressive strength of unsaturated polyester polymer concretes increase with increasing replacement ratio of rapidly-chilled steel slag. Use of rapidly-chilled steel slag was found to be effective for improving fluidity and compressive strength of rapidly-chilled steel slag.

• Nuclear Engineering and Technology
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• 제52권11호
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• pp.2607-2612
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• 2020

The present work was aimed to show the possibility of using hydrogel (acrylic/boric acid) for evaluation of the neutron radiation shielding. The influence of acrylic acid concentration, different gamma doses and relative contents of boric acid were studied. The physical properties and the thermomechanical stability of the studied samples were investigated. The shielding property of the composite for neutron was tested by Pu-Be neutron source (5 Ci) under room temperature. The neutron fluence rates and gamma fluxes were measured using a stilbene organic scintillator. The macroscopic effective removal cross-section Σ_R (cm^-1) of fast neutrons and total attenuation coefficient μ (cm^-1) of gamma rays has been studied experimentally. The transmission parameters, the relaxation length (??) and the half-value layer (HVL) were obtained. The obtained results indicated that the addition of boric acid to acrylic acid tends to increase the macroscopic effective removal cross-section Σ_R (cm^-1) to 0.141 compared to 0.094 of ordinary concrete.

• 한국자기학회지
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• 제24권2호
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• pp.66-69
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• 2014

유한요소법으로 분할 표시한 연한 X-선 퍼짐관을 설계하였다. 연한 X-선관의 모양설계 및 구체적인 좌표를 설정하고 전자빔 궤적을 OPERA-3D SW 프로그램을 이용하여 시뮬레이션하였다. 음극과 양극인 텅스텐 필라멘트와 타겟에 인가한 전압, 온도, 열전자 일함수 등을 고정하였다. 필라멘트 십자형 모양을 구비한 퍼짐관의 구조에 따른 전자빔의 분포와 초점변화를 분석하여 반도체 공정상의 정전기장 제거용 연한 X-선 퍼짐관 설계를 최적화하였다.

• 국제초고층학회논문집
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• 제2권2호
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• pp.131-139
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• 2013

The field of structural fire engineering has evolved within the construction industry, driven largely by the acceptance of performance-based or goal-based design. This evolution has brought two disciplines very close together - that of structural engineering and fire engineering. This paper presents an overview of structural systems that are frequently adopted in tall building design; typical beams and columns, concrete filled steel tube columns and long span beams with web openings. It is shown that these structural members require a structural analysis in relation to their temperature evolution and failure modes to determine adequate thermal protection for a given fire resistance period. When this is accounted for, a more explicit understanding of the behaviour of the structure and significant cost savings can be achieved. This paper demonstrates the importance of structural fire assessments in the context of tall building design. It is shown that structural engineers are more than capable of assessing structural capacity in the event of fire using published methodologies. Rather than assumed performance, this approach can result in a safe and quantified design in the event of a fire.

• Structural Engineering and Mechanics
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• 제38권2호
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• pp.157-169
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• 2011

In this paper the time-dependent closed-form static solution of the suspended pre-stressed biconcave and biconvex cable trusses with unmovable, movable and elastic or viscoelastic yielding supports subjected to various types of vertical load is presented. Irvine's forms of the deflections and the cable equations are modified because the effects of the rheological behaviour needed to be incorporated in them. The concrete cable equations in the form of the explicit relations are derived and presented. From a solution of a vertical equilibrium equation for a loaded cable truss with rheological properties, the additional vertical deflection as a time-function is determined. The time-dependent closed-form model serves to determine the time-dependent response, i.e., horizontal components of cable forces and deflection of the cable truss due to applied loading at the investigated time considering effects of elastic deformations, creep strains, temperature changes and elastic supports. Results obtained by the present closed-form solution are compared with those obtained by FEM. The derived time-dependent closed-form computational model is used for a time-dependent simulation-based reliability assessment of cable trusses as is described in the second part of this paper.

• 한국건축시공학회지
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• 제6권4호
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• pp.85-92
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• 2006

Urethane, epoxy, acrylic have common property to adhere on the concrete dried surface in the waterproofing materials at present. In the wet condition, however, the materials such as urethane, epoxy, acrylic need a long hardening time and it become a reason of water leakage as the materials breaking down. it is one of the problem to adhere to the substrate. Therefore, in this thesis, I focused to assure the structural safety and durability and quality for waterproofing and safe of construction cost by cut down the cost of labor and reduce the term of works as searching the application of field condition for high adhesive spray type of degenerated and rubberized asphalt membrane material.

• 한국건축시공학회지
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• 제3권2호
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• pp.141-148
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• 2003

This study deals with the estimation of material properties according to the construction condition for water-soluble rubberized asphalt waterproofing material of spray type. In this study, the waterproofing material property by the spray construction method is suggested by means of estimation its tensile performance and temperature dependency according to mix proportion ratio(4:1, 8:1), referenced viscosity and solid content (A:360cps, 76%, B:580cps, 79%, C:490cps, 70%), spray angle($30^{\circ}$, $45^{\circ}$, $60^{\circ}$), and spray distance(30cm, 50cm, 70cm). The result of testing are as follows. (1) The mix proportion ratio of principal agent and hardener is 4:1. (2) The viscosity referenced and solid content are 490cps and 70%. (3) The spray angle referenced is $45.^{\circ}$ (4) The distance referenced from concrete surface to spray gun is 40~50cm.

• 한국구조물진단유지관리공학회 논문집
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• 제17권4호
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• pp.91-100
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• 2013

이 연구에서는 기존아파트 외벽체의 단열 성능저하 및 보수보강에 필요한 기초 자료를 만들기 위해서 아파트의 구조체 단열성능 측정분석과 함께 단열하자에 대한 기준수립 및 평가를 하고자 한다. 또한 아파트 건축물 구조체의 열교 및 결로발생 부분을 예측하고자 하였다. 한편 시공연도별 분석에 의하여 단열기준 및 시간 경과에 따른 단열성능 정도를 분석하기 위함이다.