• Title/Summary/Keyword: Construction Material

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Interpretation of Limestone Provenance, Materials and Making Characteristics for Lime-Soil Mixture on Tomb Barrier of the Yesan Mokri Site in Joseon Dynasty (조선시대 예산 목리유적 회격묘의 재질 및 제작특성과 석회의 산지 해석)

  • Lee, Chan Hee;Cho, Ji Hyun;Kim, Jiyoung
    • Journal of Conservation Science
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    • v.32 no.4
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    • pp.471-490
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    • 2016
  • This study investigated provenance of raw materials and making technique of lime-based materials used in the tomb barriers of the Yesan Mokri tombs from Joseon dynasty on the basis of analysis to material characteristics and physical properties. In the barrier materials, dry density and porosity are the highest value ($1.82g/cm^3$) and the lowest value (25.20%) in the south wall of No. 1 tomb, respectively. Dry density and porosity are inversely proportional in all barrier materials, but unconfined compressive strength, which is the highest value of $182.36kg/cm^2$ in the No. 2 tomb, does not show an interrelation with porosity and density. Mineral components in the lime-soil mixtures of the tomb barrier are mainly quartz, feldspar, mica and calcite about 200 to $600{\mu}m$ size with yellowish brown matrix. Hydrotalcite and portlandite are detected in the lime mixture, and kaolinite in the soils. The lime materials of the tomb barrier occurred in large quantities weight loss and variable endothermic peaks caused by decarbonization reaction of $CaCO_3$ in the range from 600 to $800^{\circ}C$ in thermal analysis. Making temperature of lime for the tomb barrier is presumed approximately about $800^{\circ}C$ based on the occurrences, compositions and thermal analysis. The tomb barriers are revealed to very wide composition ranges of major elements and loss-on-ignition (22.5 to 33.6 wt.%) owing to mixture of the three materials (lime, sand and clay). It is interpreted that low quality construction technique was applied as the limes are very heterogeneous mixture with aggregates, and curing of the lime was poorly processed in the tomb barriers. Possible limestone sources are distributed in many areas around the Mokri site where limestone conformation and quarries for commercial production are found within Yesan and Hongseong areas. Therefore, we estimated that raw materials were possibly supplied from the local mines near the Mokri site.

Compare Physicochemical Properties of Topsoil from Forest Ecosystems Damage patterns (산림생태계 훼손 유형별 표토의 이화학적 특성 비교)

  • Kim, Won-Tae
    • Korean Journal of Environment and Ecology
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    • v.29 no.6
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    • pp.923-928
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    • 2015
  • This study was carried out to evaluate the physicochemical properties of different types of topsoil in forest ecosystems by damage pattern and analyse the possibility of using the topsoil as a planting ground construction material. There were 72 samples from 36 sites of 12 damaged areas and 36 sites of 12 non-damaged areas. The results showed that the physicochemical properties of topsoil from non-damaged areas of forest ecosystems were on an average clay loam~sandy loam in soil texture, showing $0.95{\sim}1.10Mg/m^3$ in soil bulk density, $35.7{\sim}44.0m^3/m^3$ in solid phase, 56.0~64.3 in soil porosity, 8.4~35.8% in aggregate stability, 5~13 mm in soil hardness, 5.3~6.1 in pH, 0.14~0.65 dS/m in EC, 0.28~0.42% in T-N, $14{\sim}22cmol^+/kg$ in CEC, $0.15{\sim}0.31cmol^+/kg$ in Ex. $K^+$, $2.07{\sim}2.84cmol^+/kg$ in Ex. $Ca^{2+}$, $0.45{\sim}1.97cmol^+/kg$ in Ex. $Mg^{2+}$, 17~96 mg/kg in Av. $P_2O_5$ and 3.2~5.6% in OM. On the other hand, damaged areas were on an average clay loam~loamy sand in soil texture, showing $1.54{\sim}1.75Mg/m^3$ in soil bulk density, $52.8{\sim}58.0m^3/m^3$ in solid phase, 42.0~47.2 in soil porosity, 4.2~22.5% in aggregate stability, 13~25 mm in soil hardness, 4.8~5.5 in pH, 0.13~0.62 dS/m in EC, 0.02~0.12% in T-N, $5{\sim}15cmol^+/kg$ in CEC, $0.11{\sim}0.18cmol^+/kg$ in Ex. $K^+$, $0.45{\sim}2.36cmol^+/kg$ in Ex. $Ca^{2+}$, $0.39{\sim}0.96cmol^+/kg$ in Ex. $Mg^{2+}$, 15~257 mg/kg in Av. $P_2O_5$ and 0.4~2.2% in OM. After conducting a comparison of physicochemical characteristics of non-damaged forest area and damaged areas, it was found that the physicochemical characteristics of damaged areas were more deteriorated compared to that of non-damaged areas. Therefore, it is judged that it is necessary to establish countermeasures for the conservation and management of the damaged areas for topsoil recycling in the future.

A Feasibility Study on the Use of Liner and Cover Materials Using Sewage Sludge (하수슬러지의 차수재 및 복토재로의 이용타당성에 관한 연구)

  • 유남재;김영길;박병수;정하익
    • Journal of the Korean Geotechnical Society
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    • v.15 no.2
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    • pp.43-71
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    • 1999
  • This research is an experimental work of developing a construction material using municipal wastewater sludge as liner and cover materials for waste disposal landfill. Weathered granite soil and flyash, produced as a by-product in the power plant, were used as the primary additives to improve geotechnical engineering properties of sludge. For secondary additives, bentonite and cement were mixed with sludge to decrease the permeability and to increase the shear strength, respectively. Various laboratory test required to evaluate the design criteria for liner and cover materials, were carried out by changing the mixing ratio of sludge with the additives. Basic soil properties such as specific gravity, grain size distribution, liquid and plastic limits were measured to analyze their effects on permeability, compaction, compressibility and shear strength properties of mixtures. Laboratory compaction tests were conducted to find the maximum dry densities and the optimum moisture contents of mixtures, and their effectiveness of compaction in field was consequently evaluated. Permeability tests of variable heads with compacted samples, and the stress-controlled consolidation tests with measuring permeabilities of samples during consolidation process were performed to obtain permeability, and to find the compressibility as well as consolidational coefficients of mixtures, respectively. To evaluate the long term stability of sludges, creep tests were also conducted in parallel with permeability tests of variable heads. On the other hand, for the compacted sludge decomposed for a month, permeability tests were carried out to investigate the effect of decomposition of organic matters in sludges on its permeability. Direct shear tests were performed to evaluate the shear strength parameters of mixed sludge with weathered granite, flyash and bentonite. For the mixture of sludge with cement, unconfined compression tests were carried out to find their strength with varying mixing ratio and curing time. On the other hand, CBR tests for compacted specimen were also conducted to evaluate the trafficability of mixtures. Various test results with mixtures were assessed to evaluate whether their properties meet the requirements as liner and cover materials in waste disposal landfill.

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Clarifying the concept of praxis in Family and Consumer Science Education -In focusing of the concept of phronesis in Aristotle's Nicomachean Ethics- (아리스토텔레스의 덕론에 기초한 가정과교육에서의 실천 개념 고찰을 위한 시론 (I) -실천적 지혜(phronesis)와 다른 덕과의 관계에 대한 논의를 중심으로-)

  • Yoo, Tae-Myung
    • Journal of Korean Home Economics Education Association
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    • v.19 no.2
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    • pp.13-34
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    • 2007
  • This study approached the concept of practical or praxis in Family and Consumer Science based on the review of the concept of phronesis in Aristotle's Nicomachean Ethics. Aristotle divided human soul into rational part and irrational part. A virtue related with rational part is intellectual virtue and a virtue related with irrational part is moral virtue. Rational part is divided into calculative part and scientific part. Phronesis is one of an intellectual virtue in calculative part of soul. Aristotle defines phronesis as a state of soul that issues in praxis. Phronesis in narrow sense is a virtue which leads to praxis and it is differ from either sophia or techne. Phronesis in broad sense it includes both praxis and poiesis. Phronesis is closely related with moral virtue. Because moral virtues are habits according to right reason, hence right reasons should be considered, and this is intellectual virtue. It is called for attention that what the concept of practical or praxis in Family and Consumer Science Education should be for the determination of the relation with Practical Arts and Technology. This study proposed a tentative conceptualization of praxis and phronimos in context of Family and Consumer Science Education.clothing planning and the most categories(83.3%) had connections of repetitions. In the clothing material section, categories evaluated as gaps and developments were 55.6% and 44.4%. The clothing construction.

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A Study on Greenspace Planning Strategies for Thermal Comfort and Energy Savings (열쾌적성과 에너지절약을 위한 녹지계획 전략 연구)

  • Jo, Hyun-Kil;Ahn, Tae-Won
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.3
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    • pp.23-32
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    • 2010
  • The purpose of this study is to quantify human energy budgets for different structures of outdoor spatial surfaces affecting thermal comfort, to analyze the impacts of tree shading on building energy savings, and to suggest desirable strategies of urban greenspace planning concerned. Concrete paving and grass spaces without tree shading and compacted-sand spaces with tree shading were selected to reflect archetypal compositional types for outdoor spatial materials. The study then estimated human energy budgets in static activity for the 3 space types. Major determinants of energy budgets were the presence of shading and also the albedo and temperature of base surfaces. The energy budgets for concrete paving and grass spaces without tree shading were $284\;W/m^2$ and $226\;W/m^2$, respectively, and these space types were considerably poor in thermal comfort. Therefore, it is desirable to construct outdoor resting spaces with evapotranspirational shade trees and natural materials for the base plane. Building energy savings from tree shading for the case of Daegu in the southern region were quantified using computer modeling programs and compared with a previous study for Chuncheon in the middle region. Shade trees planted to the west of a building were most effective for annual savings of heating and cooling energy. Plantings of shade trees in the south should be avoided, because they increased heating energy use with cooling energy savings low in both climate regions. A large shade tree in the west and east saved cooling energy by 1~2% across building types and regions. Based on previous studies and these results, some strategies including indicators for urban greenspace planning were suggested to improve thermal comfort of outdoor spaces and to save energy use in indoor spaces. These included thermal comfort in construction materials for outdoor spaces, building energy savings through shading, evapotranspiration and windspeed mitigation by greenspaces, and greenspace areas and volume for air-temperature reductions. In addition, this study explored the application of the strategies to greenspace-related regulations to ensure their effectiveness.

CO2 Fixation by Magnesium Hydroxide from Ferro-Nickel Slag (페로니켈 슬래그로 부터 제조된 Mg(OH)2를 이용한 CO2 고정화)

  • Song, Hao-Yang;Seo, Jong-Beom;Kang, Seong-Kuy;Kim, In-Deuk;Choi, Bong-Wook;Oh, Kwang-Joong
    • Clean Technology
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    • v.20 no.1
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    • pp.42-50
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    • 2014
  • In this study, the $Mg(OH)_2$ slurry was made form ferro-nickel slag and then used for $CO_2$ sequestration. The experiments were in the order as leaching step, precipitation, carbonation experiments. According to the leaching results, the optimal leaching conditions were $H_2SO_4$ concentration of 1 M and the temperature of 333 K. In the $Mg(OH)_2$ manufacturing step, NaOH was added to increase the pH upto 8, the first precipitation was confirmed as $Fe_2O_3$. After removal the first precipitation, the pH was upto 11, the $Mg(OH)_2$ was generated by XRD analysis. The $Mg(OH)_2$ slurry was used for $CO_2$ sequestration. The pseudo-second-order carbonation model was used to apply for $CO_2$ sequestration. The $CO_2$ sequestration rate was increased by the $CO_2$ partial pressure and temperature. However, $CO_2$ sequestration rate was decreased when temperature upto 323 K. After $CO_2$ sequestrated by $Mg(OH)_2$, the $CO_2$ can be sequestrated stable as $MgCO_3$. This study also presented optimal sequestration condition was the pH upto 8.38, the maximum $MgCO_3$ can be generated. This study can be used as the basic material for $CO_2$ sequestration by ferro-nickel slag at pilot scale in the future.

A Study on the Changes of Landscape Perception for 'Bejing-Palgyeong(北京八景)' in China (중국 역대 북경팔경(北京八景)의 경관인식 변화에 대한 고찰)

  • Kwon, Ji-Young;Kim, Sung-Kyun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.38 no.2
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    • pp.1-13
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    • 2020
  • This study closely analyzed poems and paintings related to Beijing-Palgyeong, as well as ancient maps and ancient writings. Through the study, people who read this study can consider, Beijing-Palgyeong's the process of changing times, changing landscape perception, physical and symbolic landscape elements, structural analysis, national management relationships, and finally how it was localized as symbolic place. The view point of the Beijing-Palgyeong is distributed in four places, one outside and one inside the city. Outside of the capital city of Beijing-Palgyeong were concentrated in Seosan(西山) where the resting place of the emperor and the center of the landscape view of Beijing. The view point of Beijing-Palgyeong inside the capital city is located in two places in the royal palace's Imperial Garden and in two villages around the fortress. In other words, Beijing-Palgyeong was selected as a place closely related to the imperial family, emperor, and royal palace from the time of its initial creation. Since then, many scholars, including the emperor, have used it for national management through Won(元), Ming and Qing Dynasty, and it have become more and more characteristic of 'The capital city of eight scenic views'. The two places inside the capital city praised the Gods and Emperors in the same way. Outside the capital city, the two sites depict the comfortable lives of the people who are governed by the emperor and depicting the village landscape around the city. In the end, it can be seen that most of the Beijing-Palgyeong are related to imperial palaces and emperors. If you look at the physical landscape of Beijing-Palgyeong by element, it mainly contains the contents of national management and the emperor's eulogy. Qianlong Emperor established the Beijing-Palgyeong in 1751 through the construction of a monument. A four-character on the front of the monument, and inscribed with a seven-word written by the person on the back. It can be said that Qianlong Emperor's Beijing-Palgyeong were intended to show off the results of Manchurian rule through the material symbol of the monument. Beijing-Palgyeong have been transformed into a landmark, and modern people use it as an indicator of the Beijing-Palgyeong.

Ecological Role of Urban Stream and Its Improvement (도시하천의 생태학적 역할과 개선방안)

  • Son, Myoung-Won
    • Journal of the Korean association of regional geographers
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    • v.4 no.1
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    • pp.15-25
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    • 1998
  • A stream plays an important role as the source of drinking water, the ecological space and the living space. But the today's urban stream whose ecosystem is destroyed and water quality become worse in consequence of covering, concrete dyke construction, and the adjustment of high-water-ground[dunchi], is deprived of the function as a stream. Therefore this paper aims to elucidate the role that urban stream plays ecologically and to try to find a improvement to the problem. A stream is the pathway through which several types of the solar radiation energy are transmitted and the place which is always full of life energy. In the periphery of a stream, primary productivity is high and carrying capacity of population is great. Thus ancient cities based on agricultural products grew out of the fertile surroundings of stream. In Korea most cities of the Chosen Dynasty Period based on the agriculture have grown out of the erosional basins where solar energy is concentrated. The role of a stream in this agricultural system is the source of energy and material(water and sediment) and a lifeline. In consequence of the growth of cities and the rapid growing demands of water supply after the Industrial Revolution, a stream has become a more important locational factor of city. However, because cities need the life energy of urban streams no longer, urban streams cannot play role as a lifeline. And As pollutant waste water has poured into urban streams after using external streams' water, urban streams have degraded to the status of a ditch. As the results of the progress of urbanization, the dangerousness of inundation of urban stream increased and its water quality became worse. For the sake of holding back it, local governments constructed concrete dyke, adjusted high-water-ground[dunchi], and covered the channel. But stream ecosystem went to ruin and its water quality became much worse after channelization. These problems of urban stream can be solved by transmitting much energy contained in stream to land ecosystem as like rural stream. We should dissipate most of the energy contained in urban stream by cultivating wetland vegetation from the shore of stream to high-water-ground, and should recover a primitive natural vigorous power by preparation of ecological park.

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Investigation and Risk Assessment of Asbestos-Containing Materials used in Buildings (건축물에 사용된 석면함유물질(ACMs)의 조사 및 위해성 평가)

  • Kim, Hong-Kwan;Chon, Young Woo;Roh, Young Man;Hong, Seung-Han;Kim, Chi-Nyon;Lee, Ik-Mo
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.28 no.1
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    • pp.35-42
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    • 2018
  • Objectives: The objectives of this study are to research the usage characteristics of asbestos-containing building materials and to conduct exposure risk assessment by applying no. 2016-230 "Methods of Risk Assessment of Asbestos-Containing Buildings" from the Ministry of Environment. Methods: One hundred buildings located in the Seoul and Gyeonggi-Incheon area were chosen, with 29 in Seoul, 20 in Incheon, and 51 in Gyeonggi-do Province. The year of construction was divided between three buildings in the 1970s, 11 buildings in the 1980s, 42 buildings in the 1990s, and 44 buildings in the 2000s. The bulk samples were analyzed by using a polarizing microscope after a pre-process using a stereomicroscope in a hood with an HEPA filter. This study defined ACMs(asbestos-containing materials) as asbestos when the content percentage was over 1% in the analysis result. Methods and standards of risk assessment of asbestos-containing building materials were conducted by refering to no. 2016-230 "Method of Risk Assessment of Asbestos-Containing Buildings" from the Ministry of Environment. The risk of exposure to ACMs was rated by a score based on three categories(high, middle, low risk of asbestos exposure). Results: In this study, 30 of the 100 buildings and 36 of the 416 bulk samples(8.6%) were found to have had asbestos. Asbestos was detected at a high rate, in 18 out of 42, in buildings constructed in the 1990s and at the lowest rate(7 out of 44) for buildings constructed in the 2000s. As a result of the evaluation according to no. 2016-230 "Method of Risk Assessment of Asbestos-Containing Buildings" of the Ministry of Environment, the risk assessment level of two asbestos-containing building materials was found to be "Medium", and 28 buildings materials were found to be at the "Low" level. Conclusion: As asbestos is regulated by the government, it is required to conduct active management and implemention by introducing methods of risk assessment of asbestos exposure that are supported by data from various situations. In the case of buildings owned by individuals, building owners should be aware of the risk of exposure to asbestos.

Evaluation of Function of Upland Farming for Preventing Flood and Fostering Water Resources (밭농사의 수자원 함양과 홍수조절 기능에 대한 계량화 평가)

  • Hyun, Byung-Keun;Kim, Moo-Sung;Eom, Ki-Cheol;Kang, Ki-Kyung;Yun, Hong-Bae;Seo, Myung-Cheol
    • Korean Journal of Soil Science and Fertilizer
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    • v.36 no.3
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    • pp.163-179
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    • 2003
  • Multifunctionality of agriculture which is not traded on the market now has been an important international issue in that it environmental and public benefits. We carried out to modify and to update the function of upland farming on flood prevention and fostering water resources. Economic values of environmental benefits were evaluated by replacement cost methods. Models to evaluate the function of preventing flood were selected as: (1)precipitation(flood-inducing) - runoff(A), (2) soil depth ${\times}$ soil air phase, (3) precipitation (flood-inducing) - runoff(B), (4) soil depth ${\times}$ effective porosity of soil. Models to estimate the function of fostering water resources were (1) saturated hydraulic conductivity (Ks) ${\times}$ duration of saturation(days) ${\times}$ (1-ratio of water flow directly into river), (2) precipitation ${\times}$ ratio of water fostered by rain resources ${\times}$ (area of upland/total land area), and (3) soil water retention quantity(under standing crop or tree) - SWRQ(in bare soil). Function of preventing flood was $883Mg\;ha^{-1}$ of water per year and 645 million Mg for the whole upland area. Function of fostering water resources was $94.1Mg\;ha^{-1}$ of water per year and 69 million Mg for the whole upland area. The value of flood-preventing function evaluated by replacement cost methods was estimated 1,428 billion won per year as compared to the cost for dam construction. The value of water resource fostering were estimated 8.6 billion won in the price of living water.