• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.71-72
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• 2023

Asbestos is a durable and heat-resistant building material used in various building materials such as slate, ceiling tex, and spray paint. It has been banned since 2009 after found to be a first-class carcinogen that causes various cancers and asbestos lung disease. Since workers are likely to be exposed to asbestos in the process of dismantling and removal of asbestos-made building materials and facilities, laws and work standards are proposed by the Ministry of Employment and Labor to ensure the safety of asbestos dismantling work. In addition, prior studies on exposure levels and analysis methods have been conducted in this regard mainly for residents. However, the relation between the results of the risk assessment of the process conducted during the asbestos investigation and the work is still ambiguous for the safety of workers. Therefore, this study proposes a process model development methodology that considers work risk based on the results of a survey from asbestos dismantling companies.

• Journal of the Korean Institute of Rural Architecture
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• v.16 no.3
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• pp.27-36
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• 2014

The purpose of this study is to provide necessary information for the establishment of remodeling range needed first to support the future remodeling of rural housing. For this, this study examined landscape characteristics of rural housing such as an outer wall, a roof, a fence, and a gate which are main elements of forming the landscape of a rural village and rural residents' perception for remodeling. The results were as follows. The subject rural housing mostly had a timber structure and a masonry structure. Common roof types were a hip-and-gable roof and a gable roof. Frequent materials were a panel, a tile, and slate and common colors were primary colors such as reddish brown, black, and gray. A fence made of cement blocks and finished by a white paint was often found. A closed gate with iron frames was common. A standup kitchen and a flush toilet inside the house were common. The family members of rural residents were mostly two including a farmer husband and his wife. Elderly people of sixty and over were the most common. For residential environment satisfaction, a half of respondents were not unsatisfied with residential environment mostly due to an old house. Most respondents who were not satisfied with residential environment had high perception for the need of remodeling. The most commonly asked remodeling part was a roof, followed by a toilet, and an outer wall, indicating that the need of exterior remodeling was higher than that of interior remodeling. For a remodeling method, a total improvement was preferred. Although some rural village housing was improved by support of the government, local governments, or social groups, there are still many old houses. As this co-existence of improved houses and old houses hinders the landscape of rural village, it is necessary to give a support. But rural residents' requests should be first actively reflected to establish a guideline of supporting rural house remodeling.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.107-107
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• 2010

Hydrogen is an alternative fuel for the future energy which can reduce pollutants and greenhouse gases. Synthesis gas have played an important role of synthesizing the valuable chemical compound, for example methanol, DME and GTL chemicals. Renewable biomass feedstocks can be potentially used for fuels and chemical production. Current thermal processing techniques such as fast pyrolysis, slow pyrolysis, and gasification tend to generate products with a large slate of compounds. Lignocellulose feedstocks such as forest residues are promising for the production of bio-oil and synthesis gas. Pyrolysis and gasification was investigated using thermogravimetric analyzer (TGA) and bubbling fluidized bed gasification reactor to utilize forest woody biomass. Most of the materials decomposed between $320^{\circ}C$ and $380^{\circ}C$ at heating rates of $5{\sim}20^{\circ}C/min$ in thermogravimetric analysis. Bubbling fluidized bed reactor were use to study gasification characteristics, and the effects of reaction temperature, residence time and feedstocks on gas yields and selectivities were investigated. With increasing temperature from $750^{\circ}C$ to $850^{\circ}C$, the yield of char decreased, whereas the yield of gas increased. The gaseous products consisted of mostly CO, CO2, H2 and a small fraction of C1-C4 hydrocarbons.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.4
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• pp.1-8
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• 2002

The place of South Weol Dynastys authorities exhumed in the region of KangChoWu, China lies adjacent to a stone ditch through which water streams crookedly, and a dark trough of stone pond in the north side. There is a sharply curved stone ditch and a crescent-shaped water entrance made by stones. The place was separated by using stone columns and stone walls. There is a beam of ditch, a crooked entrance, a flat bridge of slate, a stepping-stone, a sluice gate, and a crooked corridor. There are big and small artificial islands, and reinforcing stone drainage way in the palace pond recently exhumed at the building site for the pavilion of Hwang-Yong Temple in Kuhwang-Dong, Gyeongju city, Korea. There are four facilities assumed to be entrance and exits at four corners and an open space on which gravel was spread extensively. A narrow road and a middle road with indefinite curves at the south of Asukakyoseki exhumed by the first, second and third and two stone buckets which one is to fill with water and the other is to drain water off like fountain are there, and besides wave protecting dam and north pond and the part that water pass were excavated. Palace ponds that were extensively distributed at old residential cities are a general phenomenon of countries in eastern Asia. Anap pond of Silla and Gungnam pond of Baekje were in Kroea. We believe that Asutnkyoseki is on the extension. Although more investigations in the background of thought and the genealogical relation about the palace pond are required, it seems that an idea was surely received from China.

• Journal of Hydrogen and New Energy
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• v.21 no.6
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• pp.587-594
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• 2010

Hydrogen is an alternative fuel for the future energy which can reduce pollutants and greenhouse gases. Synthesis gas has played an important role of synthesizing the valuable chemical compounds, for example methanol, DME and GTL chemicals. Renewable biomass feedstocks can be potentially used for fuel and chemicals. Current thermal processing techniques such as fast pyrolysis, slow pyrolysis, and gasification tend to generate products with a large slate of compounds. Lignocellulose feedstocks such as forest residues are promising for the production of bio-oil and synthesis gas. Pyrolysis and gasification was investigated using thermogravimetric analyzer (TGA) and bubbling fluidized bed gasification reactor to utilize forest woody biomass. Most of the materials decomposed between $320^{\circ}C$ and $380^{\circ}C$ at heating rates of $5{\sim}20^{\circ}C$/min in thermogravimetric analysis. Bubbling fluidized bed reactor was used to study gasification characteristics, and the effects of reaction temperature, residence time and feedstocks on gas yields and selectivities were investigated. With increasing temperature from $750^{\circ}C$ to $850^{\circ}C$, the yield of char decreased, whereas the yield of gas increased. The gaseous products consisted of mostly CO, $CO_2$, $H_2$ and a small fraction of $C_1-C_4$ hydrocarbons.

• Journal of Environmental Impact Assessment
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• v.7 no.1
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• pp.81-91
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• 1998

The objective of this study was to use remotely sensed data, combined with in situ data, for the assessment of trophic state for Daecheong reservoir. Three Landsat TM(Thematic Mapper) imagery data were processed to portray trophic state conditions. The remotely sensed data and the measured data were obtained on 20 June 1995. Regression models have been developed between the chlorophyll-a concentration and reflectance which was converted to Landsat TM digital data. The regression model was determined based on the correlation coefficient which was higher than 0.7 and was applied to the entire study area to generate a distribution map of chlorophyll-a and trophic state. The equation, providing estimates of chlorophyll-a concentration, represented the year-to-year spatial variation of trophic zones in the reservoir. Satellite remote sensing data derived from Landsat TM had been successfully used for trophic slate mapping in Daecheong reservoir.

• Economic and Environmental Geology
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• v.19 no.2
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• pp.133-146
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• 1986

Primary uraninite and secondary uranium minerals such as torbernite, metatorbernite, tyuyamunite, metatyuyamunite, autunite and metaautunite have been identified from various types of uranium ores. Uranium minerals occur as accessory minerals in both the primary and secondary ores. Low·grade uranium ores consist of various kinds of primary and secondary minerals. Major constituent minerals of primary uranium ores are graphite. quartz. Ba-feldspar and sericite/muscovite, and accessories are calcite, chlorite, fluorapatite, barite, diopside, sphene, rutile, biotite, laumontite, heulandite, pyrite, sphalerite and chalcopyrite, and secondary minerals consist of kaolinite, gypsum and goethite. Uraninite grains occur as microscopic very fine-grained anhedral to euhedral disseminated particles in the graphitic matrix, showing well·stratified or zonal distribution of uranium on auto-radiographs of low-grade uranium ores. Some uraninite grains are closely associated with very fine-grained pyrite aggregates, showing an elliptical form parallel to the schistosity. Some uraninite grains include extremely fine-grained pyrite particle. Sphalerite and pyrite are often associated with uraninite in graphite-fluorapatite nodule. The size of uraninite is $2{\mu}m$ to $20{\mu}m$ in diameter. Low-grade uranium ores are classified into 5 types on the basis of geometrical pattern of mineralization. They are massive, banded, nodular, quartz or sulfide veinlet-rich and cavity filling types. Well-developed alternation of uranium-rich and uranium-poor layers, concentric distribution of uranium in graphite-fluorapatite nodule and geopetal fabrics due to the load cast of the nodule suggest that the uranium was originally deposited syngenetically. Uraninite crystals might have been formed from organo-uranium complex during diagenesis and recrystallized by metamorphism. Secondary uranium minerals such as torbernite, tyuyamunite and autunite have been formed by supergene leaching of primary ores and subsequent crystallization in cavities.

• Economic and Environmental Geology
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• v.17 no.4
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• pp.289-298
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• 1984

Uraniferous black slates of the Okchon sequence occur in Koesan (northeast) through Miwon-Boun (middle) to the southwest off Taejon (southwest) within the Okchon fold belt. The Uraniferous balck slates in the southwest off Taejon are particularly well developed in Chubu (northeast) and Moksso-ri (middle) areas whereas they are less developed in Jinsan (southwest) area. The uraniferous beds range from less than a meter to 40 meters in thickness and range from less than 0.02% $U_3O_8$ (cut-off-grade) to 0.05% $U_3O_8$ in the southwestern district off Taejon. Electron microprobe analysis of uranium-minerals found in graphitic slate samples enables to estimate their major compositions semi-quantitatively so that uraninite, ferro-uranophane and chlopinite are tentatively identified. Uranium-minerals are closely associated with carbon and metal sulfides. Correlation analysis of trace element concentrations revealed that U and F.C., and U and Mo are lineary correlative respectively and their correlation coefficients are positively high whereas those of U and V, U and Mn, and U and Zr are negatively low, implying that uranium mineralization has been closely related with concentrations of carbon and molybdenum. Stable isotope analyses of pyrite sulfur range widely from +11.5% to -23.3% in ${\delta}^{34}S$ values whereas those of graphite carbon fall within a narrow range between -23.3% and -28.9% in ${\delta}^{13}C$ values. The wide range of ${\delta}^{34}S$ values suggests that the sulfur could be of meteoric origin rather than of igneous source. The narrow range of ${\delta}^{13}C$ values, which are close to those of coal, indicates that the graphite is organic carbon in origin. Therefore, it is concluded that the uranium mineralization in the Okchon sequence took place primarily in sedimentary environment rich in organic matter and sulfide ion, both of which served as the reducing agents to convert soluble uranyl complex to insoluble uranium dioxide.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6504-6513
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• 2013

The result can be summarized as follows. First, the following periodically changing characteristics were examined:roof form(gambrel/hipped-flat-gable), structure of roof and wall(wood-framed-cement masonry-RC-Light iron framed), roof material(thatched-tiled-slate-cement/steel sheet-asphalt/sandwich panel/mortar water-proofing), wall material(clay plaster/lime plastered-dressing tile/bricks-painting on the cement plastering-native stone dressing/siding/tile), fence material(masonry of stone and cement bricks), and courtyard materials(clay and concrete). Secondly, the regionally changing characteristics of those elements, rural housing structure, roof form, roof structure material, wall finishing material, fence and courtyard material in the outer space, differed according to the location of rural housing, i.e.north, middle, south region. The changing characteristics of both the roof structure and wall structure are similar to those of the three regions.

• Journal of architectural history
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• v.20 no.2
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• pp.39-54
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• 2011

The Bunhuangsa stone pagoda, constructed in AD. 634, National Treasure no. 30, has been named as 'brick-copied pagoda' since the Japanese-ruling period by scholars. It is said that the Chinese brick pagoda was its precedent model, however the Bunhuangsa Pagoda is the oldest of all the Chinese-style brick pagodas except one, the Sungaksa Pagoda. The Chinese pagoda cannot have been a precedent model to copy due to its complex detail of wood vestige, as the Bunhuangsa pagoda is simple form without ornament. Domestic brick pagodas cannot have been a precedent model to copy as well, because all the domestic brick pagodas are younger than the Bunhuangsa Pagoda. Therefore, the terminology 'brick-copied pagoda' is a fallacy; it is rather that later brick pagoda copied the precedent the Bunhuangsa stone pagoda. The Bunhuangsa Pagoda is simply a piled-up pagoda of thick or thin, big or small slates of stone, facing only one smooth side and therefore needing nothing to relate to brick. The originality of the pagoda is more related to simple piled-up Indian stone stupa rather than Chinese brick pagoda. The roof form of its gradually stepped projection comes from the harmika of the summit of Indian stupa. Contrary to general history, old Silla Dynasty imported Buddhism directly from India by sea. From written national history and by temple foundation history, the Indian Buddhism evangelist possibly made influence to the erecting of temple and pagoda. The original wrong terminology has made a harmful effect gradually to the naming of mass-styled stone pagoda of only carved stepped-roof form after brick-copied pagoda. The false term 'brick-copied pagoda' should be discarded, which comes with superficial observation based on toadyism to China and colonialism to Japan. Instead of the fallacious term, this paper suggests multi-storied 'piled-up pagoda with slate stone.'