• Nuclear Engineering and Technology
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• 제52권10호
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• pp.2370-2378
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• 2020

Building materials contribute significantly to the indoor radon and thoron levels. Therefore, parameters that influence the exhalation rates of radon and thoron from building material need to be analyzed closely. As a preliminary study, the effects of humidity on exhalation rates were measured using a system with an accumulation chamber and RAD7 detector for Korean brick, Korean soil, and Indonesian brick. Resulting doses to a person who resides in a room constructed from the building materials were assessed by UNSCEAR method for different air exchange rates. The measurements have revealed that Korean brick exhaled the highest radon and thoron while Indonesian brick exhaled the lowest thoron. Results showed that for a typical low dense material, radon and thoron exhalation rate will increase until reached its maximum at a certain value of humidity and will remain saturated above it. Analysis on concentration and effective dose showed that radon is strongly affected by air exchange rate (ACH). This is showed by about 66 times decrease of radon dose from 0.00 h^-1 to those of 0.50 h^-1 ACH and decrease by a factor of 2 from 0.50 h^-1 to those of 0.80 h^-1. In case of thoron, the ACH doesn't have significant effects on effective dose.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.217-218
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• 2021

With the prolonged Covid-19 epidemic, movement restrictions such as social distancing are prolonged, and as people stay indoors for a longer time, interest in indoor air pollution is increasing. Indoor air quality is not easily purified unlike outdoors. Among indoor building materials, paints and flooring contain formaldehyde that causes sick house syndrome and VOCs that contain carcinogenicity and harmfulness. For modern people who spend a lot of time living indoors for more than an hour, the occurrence of these harmful substances can be said to be fatal. In response to these risks, in July 2019, the government reinforced the standards for indoor air quality to protect the public's health by raising the detection standards for fine dust, ultrafine dust, and formaldehyde in indoor multi-use facilities. People use machines such as air purifiers to improve indoor air quality, or make efforts such as periodic ventilation. In order to reduce or support these other ancillary efforts more effectively, to reduce the generation of pollutants in the building itself, or to adsorb or purify pollutants in the air, use carbon black as an admixture to make a cement hardened body, and to grasp basic physical properties and adsorption capacity. And the result is as follows. As a result of the experiment to determine the appropriate amount of carbon black, it was confirmed that the more the amount of carbon black was added, the better it was in the formaldehyde emission test, but the tendency was not clear when measuring the flexural strength, so a further experiment to improve this is needed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 가을 학술논문 발표대회
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• pp.143-144
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• 2020

For modern people who spend 80% of the day indoors, indoor air quality is an important factor in their lives. Radon and fine dust, which are indoor air quality pollutants, cause various diseases and lung diseases, so a method is needed to reduce them. Therefore, this study intends to utilize the air pollutant adsorption properties of the carbonized sludge by using the carbonized sludge generated through drying and carbonization of the sludge. As a result of the experiment, it was shown that the concentration of radon and fine dust gradually decreased as the replacement ratio of carbonized sludge increased. The reason is that the carbonized sludge has the ability to adsorb fine dust and radon, so it is considered that it gradually decreases as the replacement ratio increases. Also, the compressive strength and flexural strength tend to decrease gradually. The reason for this is that the carbonized sludge has a number of internal voids, and as the replacement ratio increases, the internal voids increase and the strength decreases. If the refinement and strength of the carbonized sludge replacement ratio are supplemented, it is believed that it will be able to replace the existing finishing materials.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.138-139
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• 2020

With the rapid progress of industrialization, indoor air quality is a very important factor for modern people who spend most of their day indoors. The recent issue of fine dust and radon on the portal site's popularity search shows that interest in indoor air quality has increased. Fine dust causes respiratory diseases, and radon causes severe lung cancer. The new material was tested using plant activated carbon, palm activated carbon and bamboo activated carbon. Both palm activated carbon and bamboo activated carbon are porous materials and generate smooth physical adsorption. As a result of the experiment, both the activated carbon tends to gradually decrease in strength and fluidity as the replacement ratio increases. The reason for this is that both activated carbons have the property of absorbing moisture, so it is judged that the strength is lowered by absorbing moisture necessary for curing. In the case of fluidity, it is judged that the fluidity is reduced by absorbing the moisture required for the flow. In the future, if the problem of the color of the finished cured body is compensated, it will be possible to manufacture a functional finishing board to replace the existing interior finishing material.

• KIEAE Journal
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• 제8권2호
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• pp.53-58
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• 2008

With architectural technology, a building has been a far dense and close. So the thermal environment of the building has become pleasant, but the quality of indoor air has been degraded. Using synthetic products for construction materials and furniture indoors escalates the concentration of volatile organic compounds(VOCs) at indoor air, threatening the health of the residents. To reduce the concentration of volatile organic compounds at indoor air, many methods are designed, and of late, concern has been increased about the effect of air purification using air purifying plants. Field measurements were performed using Aglaonema brevispathum, Pachira aquatica and Ficus benjamiana, which were verified as air-purifying plants by NASA. The effect of reducing the concentration of air contaminants by plant studied in a full scale mock-up model. The variations of concentration of Benzene, Toluene, Ethylbenzene and Formaldehyde were monitored. In most cases, the effect was excellent in Toluene and formaldehyde in summer.

• 분석과학
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• 제18권4호
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• pp.344-354
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• 2005

최근 들어 실내공기질 악화의 주 오염원인 건축자재에 대한 관심이 고조되면서 건축자재 오염물질 방출시험 자료 구축이 중요하게 됨에 따라, 신뢰성 있는 자료 확보를 위해 건축자재 방출시험 정도 관리에 대한 필요성이 대두되었다. 이에 본 연구는 건축자재 방출시험 성능에 대한 정도관리를 위해 총 휘발성 유기화합물과 포름알데히드에 대하여 기기분석 재현성, 회수율, 검출한계, 중복 및 반복채취 재현성, 파과용량 평가 등을 실시하였다. 기기분석 및 시료채취에 대한 재현성은 20~30% 이내의 양호한 결과를 보였으며, 회수율은 80% 이상으로 나타났으며, 파과 역시 일어나지 않아 소형챔버법에 의한 성능은 전반적으로 만족할 만한 수준을 보였다. 따라서, 소형챔버를 이용한 건축자재 오염물질 방출시험방법은 신뢰성있는 자료를 제공해 줄 수 있을 것으로 판단된다.

• 토지주택연구
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• 제14권4호
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• pp.103-110
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• 2023

하루 평균 대부분을 실내에서 보내는 현대인들은 내외부적으로 발생하는 실내오염물질에 지속적으로 노출되고 있다. WHO(World Health Organization) 2022년 보고서에 따르면 매년 세계적으로 약 700만명 이상의 사망 원인이 공기오염으로 실내오염물질의 심각성을 강조하고 있다. 대기오염물질 중에는 인체에 심각한 영향을 끼치는 질소산화물(NOx), 폼알데하이드(HCHO), 휘발성 유기화합물(VOCs) 등이 포함되는데, 이러한 실내공기 오염물질을 제거할 수 있는 물질로 광촉매가 있다. 광촉매는 미세먼지 전구물질 제거 성능뿐만 아니라 향균, 살균, 탈취 성능 또한 가지고 있어, 실내공기질 개선에 효과적이다. 이에, 본 연구에서는 광촉매를 건축물에 적용할 수 있는 부위 및 방안을 제시하였다. 적용 가능한 부위로는 내외장재, 콘크리트 등을 포함한 건축자재, 유기도료, 환기장치 등이 있으며, 각 부위에 최적 적용 방안에 대한 연구를 진행하였다.

• 설비공학논문집
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• 제8권3호
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• pp.397-412
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• 1996

This study aims to present the fundamental strategies to improve the Indoor Air Quality (IAQ) in apartment buildings. To investigate the concentration of indoor air pollutants such as radon, formaldehyde, and VOCs, both the document survey and the field measurement were conducted. In addition, to identify the source of the air pollutants, the laboratory experiment was carried out for various building materials. Finally, the minimum period to be reserved befor3e building occupation to ensure healthy IAQ, which largely depends on the ventilation rates, was simulated using a simple compuer program. The results of this study can be summarized as follows: 1. In case of newly-constructed apartment houses, concentrations of formaldehyde, VOCs and radon were found to exceed the standard. Meanwhile, at existing apartment houses, concentrations of VOCs, particularly toluene and xylene, highly exceeded the standasrd level. Concentrations of formaldehyde and radon, however, had been lowered according to the duration of occupation. 2. The laboratory experiment of concentration of pollutants per square meter of building material surface area showed that radon gas was much emitted from the gypsumboard; formaldehyde from flooring and wallpaper; and VOCs from paints and kitchen furnishings. The emission rates of formaldehyde and VOCs were proportional to air temperature. 3. According to the simulation of the minimum period to be reserved before occupation, newly-constructed airtight houses required about 190-200 days, and naturally ventialted houses with fully-open-windows required about 20-45days, in order to keep the level of radon gas lower than standard. Therefore, with the current practice, the date of occupation should be delayed for about 15 days.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.93-94
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• 2022

Although various studies about indoor positioning systems, such as beacon and Wifi, have been conducting for indoor positioning of workers at construction sites, these systems have limitations in terms of accuracy or economics. To overcome these limitations, geomagnetic field sequence-based indoor positioning technology can be a good alternative. However, it is necessary to correct the geomagnetic field near the construction material stocking area since the geomagnetic field can be distorted near construction materials such as rebars. Therefore, this study conducted an experiment for identifying correction range of geomagnetic field near the construction material stocking area. It was analyzed that the geomagnetic field should be corrected up to 60cm in the horizontal direction from the stocking point if the height of stocking area for rebars is 40cm or more. This study can be used for important reference for development of geomagnetic field sequence-based indoor positioning technology suitable for construction sites.

• 한국환경과학회지
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• 제21권1호
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• pp.11-21
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• 2012

This study investigated the characteristics of selected volatile organic compounds(VOCs) in newly-finished residential buildings, before the occupants moved in. This investigation was carried out by measuring the indoor and outdoor concentrations of selected VOCs before the occupants moved in and by utilizing an indoor mass balance model. Among 25 target VOCs, five aromatics(benzene, ethyl benzene, toluene, m,p-xylene, and o-xylene) were detected in all samples of both indoor and outdoor air. Toluene was most abundant VOC in the indoor air of new apartments, with a median value of 168 mg $m^{-3}$. Unlike other VOCs, halogenated compounds would not be significantly emitted from building materials. The indoor air concentrations of all selected VOCs, except for 1,3,5-trimethyl benzene, exhibited significant correlations each other, while for outdoor air concentrations, five aromatics only were significantly correlated between them. The emission rate of toluene was higher for the current study(median value, 76.8 mg $m^{-2}\;h^{-1}$) than for a previous study, while the emission rates of limonene, a-pinene and b-pinene(geometric means of 2.4, 13.8 and 9.6 mg $m^{-2}\;h^{-1}$, respectively) were lower and the emission rates of m,p-xylene and 2-butanone(geometric means of 10.9 and 21.3 mg $m^{-2}\;h^{-1}$, respectively) were similar. Although there were a few exceptions, the emission strengths are likely proportional to indoor temperature, and appear to reversely proportional to air exchange rate.