• Journal of Conservation Science
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• v.30 no.4
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• pp.335-343
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• 2014

This study classified the result of non-metallic inclusion analysis and result of microstructure investigation on the ironware excavated in the Baekje region into Han River, Geum River, and Yeongsan River to estimate the iron making temperature and study the characteristics of regional and temporal characteristics of the heat treatment technology and steel making technology. Regardless of era, bloom iron and sponge iron are judged to be the major method for making as a directreduction process in all three regions. The result of the reinterpretation of the non-metallic inclusion by the oxide ternary constitutional diagram suggest that the temperature inside of the furnace is estimated to be between $1,100{\sim}1,300^{\circ}C$ while making the steel. The magnetic iron ores are the major raw material of steel ore and irons with high $TiO_2$ are estimated to use iron sands. Ironware with $CaO/SiO_2$ rate higher than 0.4% are considered to have artificially added the flux of calcareous materials. It was found that the iron making method is the solid caburizing-steel which caburizes low-carbon steels by the CO gas and $CO_2$ gas created when heating the forging furnace with charcoal. Also, the ironware manufacturers in the Baekje during 3rd century recognized the heat treatment technology as they performed carburizing process and quenching to intentionally increase the strength of necessary parts.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1777-1787
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• 2000

The purpose of this study was to select an effective and economical alkali source for sulfur-utilizing autotrophic denitrification. Tests on acid neutralization and denitrification at various alkali/sulfur mixing ratios were performed for charcoal, briquette ashes, sea shell, and limestone. The results of the experiments showed that sea shell was the most effective alkali source because it could provide more surface area than limestone, and the optimal alkali/sulfur mixing ratio was 1/1(V/V). In a sulfur/sea shell packed bed reactor, the denitrification efficiency was above 90% up to a loading rate of 116 g $NO_3{^-}-N/m^3-day$. but the denitrification efficiency deteriorated to 48% at the loading rate of 145 g $NO_3{^-}-N/m^3-day$. The average $SO_4{^{2-}}$ generation per g of $NO_3{^-}-N$ removed was 7.02 g, which is lower than the theoretical value of 7.54 g. Denitrification and sulfate generation appeared to be a first-order and a zero-order reaction with a reaction rate constant of 0.146 /hr and -53.1 mg/L-hr, respectively. According to nitrogen mass balance, 71~109%, with an average of 90%, of the removed nitrogen was recovered as $N_2$ gas.

• Journal of Korean Society of Forest Science
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• v.94 no.3 s.160
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• pp.135-145
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• 2005

The purpose of this study is to reveal the component characteristics and the channels of distribution for forest products as a fuel that were consumed in Kyeongseong city (Seoul) in 1929, in the middle of the colonial period. The summary of the results are as follows; (1) though the average consumption of forest products consumed as a fuel per household in Kyeongseong city was slightly less than one-third as much forest products as fuel consumed in other counties of Kyeongki province, but due to the high heat capacity, the amount of fuelwood and charcoal consumption was much higher than leaf and grass consumption; (2) the largest supply areas of forest products for fuel were the riverside of Kangwon province and Kyeonggi province in which the waterways were available. They supplied 42.6% of total consumption, and the other supply areas were the northern part of Kyeonggi province, etc. (29.5%) where railroads were handy, and the suburbs of Kyeongseong City (27.9%) by roads; (3) the transportation areas using the Han River were divided into two parts of Ttook island (43.0%) and former Yongsan and Mapo (45.6%), but the volume of transportation by railroad was centralized in Kyeongseong Station, which accounted for 72.2% of total volume of transportation by rail; (4) the most of the forest products consumed for fuel in Kyeongseoung city were sold in temporary fuelwood markets, rather than permanent and regular markets.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.96-101
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• 2010

One of the restriction of wood as building material is its combustibility. The purpose of this paper is to examine the combustion properties of the quercus variabilis and zelkova serrata which are dried at room temperature and meet the desirable characteristics for use of construction materials. The cone calorimeter (ISO 5660-1) was used to determine the heat release rate (HRR) and fire smoke index, as well as CO production and smoke obscuration. The $HRR_{mean}$ 77.94 kW/$m^2$ of the quercus variabilis at 50 kW/$m^2$ was high in comparison with $HRR_{mean}$ 13.06 kW/$m^2$ for the zelkova serrata. Furthermore, the quercus variabilis has high specific extinction area ($SEA_{mean}$), 41.11 $m^2$/kg compared with $SEA_{mean}$ 9.23 $m^2$/kg of zelkova serrata. Thease results are depend on the density of tested wood species. In addition, the quercus variabilis has high CO production rate compared with that of zelkova serrata. Also, zelkova serrata showed an increase of retardant properties attributed to char formation compared with that of quercus variabilis.

• Korean journal of food and cookery science
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• v.24 no.6
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• pp.876-881
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• 2008

The aim of this study was to evaluate the quality characteristics and antioxidant activities of green tea garlic paste added calcium. Garlic was heated with green tea and charcoal at high temperature ($120^{\circ}C$) and high pressure ($1.5\;kgf/cm^2$) for 20 min, and then added several calcium sources (calcium carbonate, calcium citrate, calcium lactate, mixed calcium, calcium powder). Calcium carbonate, mixed calcium or calcium powder significantly increased pH of green tea garlic paste (p<0.05). All kinds of calcium sources significantly increased the viscosity of green tea garlic paste (p<0.05). Solid soluble content of green tea garlic paste was increased only in calcium citrate and calcium powder groups. Lightness, redness and yellowness of green tea garlic paste with calcium were increased, compared with control group (green tea garlic paste without calcium). The antioxidant activities by DPPH and hydroxyl radical scavenging activity of green tea garlic paste added calcium citrate, calcium lactate or calcium carbonate group were much higher than those of the other control groups. The garlic odor and garlic taste by sensory test were significantly weaker in calcium carbonate or calcium citrate group (p<0.05). Based on these results, it was suggested that calcium carbonate or calcium citrate is appropriate material for deodorizing and fortifying agent for green tea garlic paste.

• Asian Journal of Turfgrass Science
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• v.20 no.1
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• pp.107-118
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• 2006

This study was carried out to introduce a couple of commercialized patented technologies in the area of turfgrass production. All sod production related patents in Korea during the period from Dec. 20, 1948 to Dec. 30, 2005 were reviewed. Details of two patents (patent No. 0434389 and 0478194) were included. The results are summarized as follows: 1. One of the domestic patents on sod production was the technique using natural and plastic films. Information on topsoil mixtures was also reviewed form foreign patents. 2. Patented multi-purpose sowing equipment can evenly mix soil, sand, fertilizer and other soil conditioners with seed, stolen and rhizome of turfgrass. 3. Patent on cool-season turfgrass sod production provide topsoil mixture combination and mixing ratio for sports field, landscape area and roof garden.

• Journal of the Korean Wood Science and Technology
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• v.37 no.1
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• pp.12-18
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• 2009

This study was attempted to investigate indoor air quality of a wooden house. Emission characteristics of carbonyl compounds from indoors whose interiors were finished using ecofriendly materials were detected. From the results of the examination, the carbonyl compounds mostly consisted of formaldehyde, acetaldehyde, and hexaldehyde. Especially, formaldehyde accounted for the largest portion of the compounds at 25.6~30.5%. All the rooms except for R2-2 contained formaldehyde less than criteria of indoor air quality of newly-constructed houses. In addition, all the rooms except for room R1-3, contained acetaldehyde more than the level of $48{\mu}g/m^3$ recommended by Japan's Ministry of Health, Labour and Welfare. As a results of the different wall covering, the room R1-1 of Hwangto emitted relatively higher levels of carbonyl compounds than the room R2-1 of phytoncide. In addition, the room R2-2 of the bamboo charcoal panels emitted more carbonyl compounds than the room R1-2. The living room R1-3 of Japanese cypress (Cryptomeria Japonica) emitted lower levels of carbonyl compounds than other rooms.

• Journal of Conservation Science
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• v.33 no.5
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• pp.355-362
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• 2017

The Nongso tomb of Sunchang was built in a relatively deep place; hence there was little damage from grave robbers. The tomb was completely filled with a large amount of charcoal, and therefore the wooden coffin was excavated in relatively good condition. On the basis of the structure of the tombs, excavated artifacts, and radiocarbon dating results, the tomb is estimated to be from between the late Goryeo and the early Joseon period. The wooden coffin excavated is double-layered structures consisting of an outer coffin and an inner coffin. The outside of the wooden coffin is thickly lacquered and decorated with yellow letters and white motifs. An analysis of the pigments' components revealed that the major component of the letters was gold (Au) and the major component of the motifs was silver (Ag). The coffin lacquer had three layers: a pigment layer, a yellowish-brown layer, and a black layer. The wooden bases of the coffins were painted with a black substance, such as soot, as mineral elements were not detected in the black layer. The yellowish-brown layer is presumed to be refined lacquer. From the analysis of the structure of the layers and pigments, we can estimate the method was adopted for making lacquer for wooden coffin. It is assumed that the method used gold leaf and gold powder. The form of the pigment and the internal structure are likely to be gold leaf, but the shape of the surface letters appears to have been formed using gold powder. This study will serve as important information for understanding lacquer making techniques at the time of the tombs' construction by confirming the making method through reproduction experiments using gold leaf and gold powder.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.6-6
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• 2018

본 연구에서는 고문헌에 기록된 도금 재료와 도금법 등을 확인하고 이를 기초자료로 활용하여 매실산을 사용한 금(Au)-수은(Hg) 아말감기법으로 고대 도금(鍍金)기술을 되살리고, 이를 토대로 경주 월지에서 출토된 금동삼존판불을 복원하였다. 먼저, 전통 도금법을 되살리기 위해서, "오주서종박물고변", "확지신편", 조선시대 각종 의궤 등에 공통적으로 기록되어 있는 매실에 주목하고, 매실을 3~4개월 발효 숙성 후 착즙한 뒤 그것을 농축하여 만든 매실산을 도금 실험에 적용하였다. 금아말감 도금을 위하여 월지 출토 금동삼존판불의 바탕소지금속인 청동삼존판불을 구리와 주석 89:11(Cu:6kg, Su:750g)로 합금하여 주물사 주조법으로 복원하였으며, 동일한 합금비로 제작된 $2.3cm{\times}3.5cm$(가로${\times}$세로)의 시편에 사전 실험을 실시하였다. 현대적 산처리 방식에 사용되는 질산과 전통방식으로 사용되는 매실산으로 시편에 산처리 한 후 각각 비교해 보고, 금분과 금박, 상온과 가온에 따른 아말감상태를 비교하는 실험을 진행하였는데, 실험에 사용된 매실산 70%는 pH가 1.94로, 오늘날 산처리에 사용하고 있는 질산 20%와는 차이가 있지만, 청동 시편 실험을 통해 매실산에 20분 정도 담근 뒤 금아말감을 도포 후 24시간 지나 가열($380{\sim}400^{\circ}C$) 했을 때 금도금이 잘 되어, 현대적 방법인 질산처리로 도금을 한 시편과 큰 차이가 없는 것으로 관찰되었다. 사전 실험을 통한 결과를 적용한 월지 출토 금동삼존판불 복원은 청동삼존판불 표면처리, 금-수은 합금 및 도금하기, 도금 후 표면처리의 순서로 진행되었는데, 금과 소지금속의 밀착력을 높이기 위해 표면을 숯을 이용해 탈지한 후 물로 씻어내고 매실산을 도포하여 20분 동안 두어 부식 및 세척을 시행하였다. 금도금을 위한 금-수은아말감은 가온할 때 수은이 증발하는 양을 고려하여 금1 : 수은10 비율로 합금하여 완성하였으며, 금아말감 도포 후 약 24시간 지난 다음, $380{\sim}400^{\circ}C$에 가열하여 수은을 기화시켜 도금작업을 완성하였다. 금아말감도금은 평균적으로 6~7차례 시행하여야 완벽히 도금되지만, 본 연구에서는 단 4차례의 도금만으로 금아말감도금을 완성시켰는데, 이것은 금아말감을 바탕소지인 청동에 도포한 후 24시간 동안 금아말감과 청동과의 반응 시간을 두게한 것이 큰 역할을 한 것으로 보이며, 이는 청동시편을 이용한 실험과 과학적 분석을 통하여 입증하였다. SEM으로 표면을 관찰한 결과 아말감 도포시간이 즉시인 경우 도금이 거의 되지 않은 것을 확인할 수 있었고 36시간이 넘어갈 경우 금 도금층이 불균일하게 관찰되었으므로 도금시간은 12시간~24시간 이내가 적절함을 확인할 수 있었다. EDS로 성분을 분석한 결과 산처리 시간이 20분인 시료의 경우 5 wt% 내외로 수은의 비율이 다른 시료에 비해 낮은 것을 확인할 수 있었다. 실험 및 분석결과 산처리 시간이 20분이고 아말감 도포시간이 24시간일 때 도금이 잘 이루어지므로 이 결과를 토대로 금동삼존판불을 복원하였다. 이번 연구를 통해 도금법에 표면을 세척하고 부식시키기 위해 사용한 물질이 매실산임을 찾아내어 확인할 수 있었는데, 이러한 점 에서 이 연구의 가장 큰 의미는 전통 소재와 기술을 복원한 것으로, 앞으로 매실산을 이용한 금 도금기술은 관련 학계에도 큰 기여를 할 것으로 기대된다.

• Korean Journal of Heritage: History & Science
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• v.48 no.4
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• pp.138-153
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• 2015

A Jincheon Seokjangri B23 furnace was reconstructed and iron smelting experiment was performed to investigate an ancient Baekjae iron production process. The work mainly described in this paper is the $1^{st}$ and $2^{nd}$ experiments among the several experiments carried out at Jungwon National Research Institute of Cultural Heritage. Iron ore(magnetite) and oak charcoal were used as a source and a foot bellow was used for air supply. Common results of the experiments are masses of iron, slag and charcoal formed in the furnace. Most iron lumps were formed nearby the tuyere rather than the area of tapping hole. Metallographic and chemical analysis shows that the iron lumps can be used for either forge or cast depending on their carbon content. Low Fe content and glassy texture of the inner slags suggest that the operation environment was quite reducing. Based on the results of the iron smelting experiments, measurements and analysis, various information was obtained regarding physical-chemical and metallurgical processes of the ancient iron smelting process. It is firmly believed that its undisclosed contents can be revealed more in depth with continual reconstitution experiments.