• 감성과학
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• 제18권3호
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• pp.3-16
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• 2015

오렌지 과즙이 생생하게 표현된 영상과 함께 제시된 오렌지 향은 영상실감을 향상시킬까? 혹은 남녀 간의 데이트 장면에 로맨틱한 향을 제시한다면 영상실감이 향상될까? 전자는 영상에 구체적인 대상 혹은 장소가 존재할 때 향을 활용하여 영상실감을 향상시키는 경우라면, 후자는 그렇지 않은 경우 향을 활용하여 실감향상을 시도하는 경우이다. 본 논문에서는 위의 두 가지 질문에 답하기 위해 다양한 영상과 향에 대한 수용도와 감성에 대한 심리적 측정을 진행해 온 선행 연구들을 종합하고, 이 연구들이 주는 시사점과 한계, 연구 전망에 대해 논의하고자 한다. 특히 후각정보 수용도, 향 유사성 지각, 영상의 후각적 생생함과 영상실감, 향 감성에 부합하는 색상, 색온도, 그리고 감성 형용사를 측정한 방법과 결과에 초점을 맞춰 논의할 것이다. 본 연구가 영상실감을 위해 향을 사용하고자 하는 연구자 혹은 공학자들에게 큰 도움을 줄 것으로 기대한다.

• 한국강구조학회 논문집
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• 제18권5호
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• pp.643-654
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• 2006

본 연구에서는 iTECH 합성보 실험체에 대한 온도와 변형에 대한 내화성능을 ISO834 표준화재와 BS476-20 및 KSF2257 기준에 근거하여 평가하였다. 국내외적으로 복합구조의 내화성능을 규명하기 위한 연구는 지극히 미흡한 실정이며, 따라서 본 연구에서는 iTECH 합성보의 내화성능을 평가하기 위해 1.5m의 슬래브를 포함한 4..7m의 스팬길이에 대하여 실험을 수행하였다. 변수는 실험체의 단면크기, 피복재 보강방법과 보강두께, 그리고 하중비로 하여 내화실험을 수행하였다.

• 한국지반공학회논문집
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• 제33권8호
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• pp.17-27
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• 2017

우리나라 북동부에 위치하고 있는 강원지역은 겨울철 일 평균온도가 영상권을 유지하는 타 지역들과는 달리 일평균온도가 영하로 떨어지는 가장 추운 지역이다. 이에따라 지속적으로 도로터널의 라이닝부에 대한 동결피해 발생 사례가 보고되고 있으나 동결피해 저감을 위한 단열설계 기준 및 관련 연구는 아직까지 매우 부족하다. 본 연구에서는 단열공법 적용에 따른 도로터널의 동결저감 효과를 분석하기 위하여 겨울철 강원지역 도로터널의 지반특성과 기후특성을 고려한 해석적 연구를 수행하였다. 그 결과, 라이닝부의 콘크리트와 숏크리트 두께의 차이는 동결심도에 큰 영향을 미치지 않는 것으로 나타났으나 단열재의 적용 시에는 동결심도가 크게 감소하는 것으로 나타났다. 또한 배면지반의 열전도율과 외기온도 지속지간의 변화에 따라서 동결심도가 큰 영향을 받으므로 이러한 영향을 고려하여 단열재의 두께를 산정하여 적용한다면 우수한 동결저감 효과를 보일 것으로 판단된다.

• Earthquakes and Structures
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• 제13권3호
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• pp.267-277
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• 2017

Base-isolation is now being adopted as a retrofitting strategy to improve seismic behaviour of reinforced concrete (r.c.) framed structures subjected to far-fault earthquakes. However, the increase in deformability of a base-isolated framed building may lead to amplification in the structural response under the long-duration horizontal pulses of high-magnitude near-fault earthquakes, which can become critical once the strength level of a fire-weakened r.c. superstructure is reduced. The aim of the present work is to investigate the nonlinear seismic response of fire-damaged r.c. framed structures retrofitted by base-isolation. For this purpose, a five-storey r.c. framed building primarily designed (as fixed-base) in compliance with a former Italian seismic code for a medium-risk zone, is to be retrofitted by the insertion of elastomeric bearings to meet the requirements of the current Italian code in a high-risk seismic zone. The nonlinear seismic response of the original (fixed-base) and retrofitted (base-isolated) test structures in a no fire situation are compared with those in the event of fire in the superstructure, where parametric temperature-time curves are defined at the first level, the first two and the upper levels. A lumped plasticity model describes the inelastic behaviour of the fire-damaged r.c. frame members, while a nonlinear force-displacement law is adopted for the elastomeric bearings. The average root-mean-square deviation of the observed spectrum from the target design spectrum together with a suitable intensity measure are chosen to select and scale near- and far-fault earthquakes on the basis of the design hypotheses adopted.

• Advances in concrete construction
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• 제9권6호
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• pp.547-556
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• 2020

This study aimed to develop reference materials (RMs) that are chemically stable and can simulate the flow characteristics of cement paste. To this end, the candidate components of RMs were selected considering the currently required properties of RMs. Limestone, slag, silica, and kaolin were selected as substitutes for cement, while glycerol and corn syrup were selected as matrix fluids. Moreover, distilled water was used for mixing. To select the combinations of materials that meet all the required properties of RMs, flow characteristics were first analyzed. The results revealed that silica and kaolin exhibited bilateral nonlinearity. When an analysis was conducted over time, slag exhibited chemical reactions, including strength development. Moreover, fungi were observed in all mixtures with corn syrup. On the other hand, the combination of limestone, glycerol, and water exhibited a performance that met all the required properties of RMs. Thus, limestone, glycerol, and water were selected as the components of the RMs. When the influence of each component of the RMs on flow characteristics was analyzed, it was found that limestone affects the yield value, while the ratio of water and glycerol affects the plastic viscosity. Based on this, it was possible to select the mixing ratios for the RMs that can simulate the flow characteristics of cement paste under each mixing ratio. This relationship was established as an equation, which was verified under various mixing ratios. Finally, when the flow characteristics were analyzed under various temperature conditions, cement paste and the RMs exhibited similar tendencies in terms of flow characteristics. This indicated that the combinations of the selected materials could be used as RMs that can simulate the flow characteristics of cement paste with constant quality under various mixing ratio conditions and construction environment conditions.

• 한국구조물진단유지관리공학회 논문집
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• 제19권1호
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• pp.128-138
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• 2015

탄산화는 지하구조물과 같이 이산화탄소의 농도가 높고 강우로부터 보호되는 콘크리트 구조물에 매우 심각한 열화현상이다. 탄산화 깊이 및 수화물의 변화를 평가하기 위해 많은 연구가 진행되고 있으나 해석모델의 복잡성, 이산화탄소 확산계수 모델링 등의 어려움으로 인해 실제 탄산화 거동을 제한적으로 모사하고 있다. 본 연구에서는 기존의 탄산화 모델링 (Ducom)에 대하여 확산계수 모델링, 공극률 감소 모델, 이산화탄소의 장기반응률 등을 개선하여 개선된 탄산화 모델을 제시하였다. 검증을 위하여 온도변화를 고려한 촉진탄산화 시험. 공극률 평가 시험 (수은압입법)을 수행하였으며, 탄산화 깊이를 개선되기 전/후의 모델과 비교하였다. 또한 수산화칼슘의 중량변화와 실태조사결과를 이용하여 낮은 이산화탄소에 노출된 콘크리트 구조물의 탄산화 깊이를 제안된 모델과 비교하였다. 제안된 모델은 확산계수 감소성, 공극률 감소성을 적절하게 반영하여 기존의 모델에 비해 합리적인 결과 (수산화칼슘 소모량, 탄산화 깊이)를 나타내었다.

• 펄프종이기술
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• 제32권4호
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• pp.66-73
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• 2000

Alkaline sulfite-anthraquinone(AS-AQ) cooking process has been applied to unground pine bark. The properties of the spent liquor such as molecular weight distributions, sulfonic equivalent weights, degree of sulfonation, phenolic hydroxyl groups and kaolin dispersing ability have been investigated to evaluate the possibility of using this liquor as concrete additives or binders. In the case of ground bark meal, more than 90% delignification was achieved at the optimal cooking conditions. However, applying these conditions on unground bark the delignification was slightly retarded. The decrease in the degree of delignification may be attributed to less penetration and diffusion of chemicals during the cooking of the bark. Increasing the cooking temperature only by $5^{\circ}C$ improved the delignification of the bark and about 90% delignification can be achieved. These results indicate that bark can be used successfully during AS-AQ cooking without any mechanical or physical pretreatment. The properties of lignin or polyphenol sulfonates in the spent liquor after AS-AQ cooking of the bark were compared with Sunflo-R, which is commercial lignosulfonate(CLS) prepared from wood. The weight average molecular weights(Mws) estimated by gel-filteration chromatography was found to be ranging from 1,200~1,800. These are considerably lower than those in CLS. Lignin or polyphenol sulfonates in the spent liquor of bark and CLS have similar degree of sulfonation, but the phenolic hydroxyl group was 1.8 times higher than CLS. Moreover, the dispersing abilities of the spent liquors were better than that of CLS, especially after 0.1% addition to kaolin suspension.

• Steel and Composite Structures
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• 제34권4호
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• pp.487-497
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• 2020

During the last few decades, fluid viscous dampers have been significantly improved in terms of performance and reliability. Viscous dampers dissipate the input energy into heat and the increased temperature may damage internal seals of the damper. As a result, thermal compensation is crucial for almost all fluid viscous dampers. In this study, while referring to the main working principles of the recently developed bypass viscous damper in Iran, a comprehensive case study is conducted on a RC building having diagonal braces equipped with such viscous dampers. Experimental results of a small-scale bypass viscous damper is presented and it is shown that the currently available simplified Maxwell models can simulate behavior of the bypass viscous damper with good accuracy. Using a case study, contribution of bypass viscous dampers to seismic behavior of structural and non-structural elements are investigated. A designed procedure is adopted to increase damping ratio of the building from 3% to 15%. In this way, reductions of 25% and 13% in the required concrete and steel rebar materials have been achieved. From nonlinear time history analyses, it is observed that bypass viscous dampers can greatly improve seismic behavior of structural elements and non-structural elements.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.101-101
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• 2018

Quantitative measurement of chloride ion concentration has an important role in various fields of electrochemistry, medical science, biology, metallurgy, architecture, etc. Among them, its importance of architecture is ever-growing due to unexpected degradations of building structure. These situations are caused by corrosion of reinforced concrete (RC) structure of buildings. And chloride ions are the most powerful factors of RC structure corrosion. Therefore, precise inspection of chloride ion concentration must be required to increase the accuracy of durability monitoring. Multi-walled Carbon nanotubes (MWCNTs) have high chemical resistivity, large surface area and superior electrical property. Thus, it is suitable for the channels of electrical signals made by the sensor. Silver nanoparticles were added to giving the sensing property. CuBTC, one of the metal organic frameworks (MOFs), was employed as a material to improve the sensing property because of its hydrophilicity and high surface area to volume ratio. In this study, sensing element was synthesized by various chemical reaction procedures. At first, MWCNTs were functionalized with a mixture of sulfuric acid and nitric acid because of enhancement of solubility in solution and surface activation. And functionalized MWCNTs, silver nanoparticles, and CuBTC were synthesized on PTFE membrane, one by one. Electroless deposition process was performed to deposit the silver nanoparticles. CuBTC was produced by room temperature synthesis. Surface morphology and composition analysis were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), respectively. X-ray photoelectron spectroscopy (XPS) was also performed to confirm the existence of sensing materials. The electrical properties of sensor were measured by semiconductor analyzer. The chloride ion sensing characteristics were confirmed with the variation of the resistance at 1 V.

• 한국재난관리표준학회지
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• 제3권1호
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• pp.43-50
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• 2010

도로에서 발생하는 사고 중 도로결빙에 의한 미끄러짐 사고비율이 높으며, 특히 상습 결빙 지역인 교량과 터널 입출부에서 발생 빈도가 높게 나타난다. 이렇게 부분적으로 발생되는 결빙 현상을 방지하여 도로운영의 안정성을 높이고자 한다. 지열 융설의 기초 연구를 통해 일반 도로포장 재료인 콘크리트, 아스팔트 두 종류의 재료에 대한 융설시 열전도 양상을 파악하고자 한다. 지열융설 시스템 적용시 포장체 하부 열교환 파이프 매설에 따른 열전도도 연구가 필요하다. 도로 포장과 동일 재질의 시험체를 제작하여 냉동고에서 저온상태의 모형시험을 수행 하였고, 모형시험과 동일 조건의 수치해석을 통해 보다 다양한 융설에 대한 변수를 파악하였다.