• Title/Summary/Keyword: 탄산

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A Study on the Dental Discolouration Measurement due to the Temperature Variation (온도 변화에 따른 치아 변색 측정에 관한 연구)

  • Oh, Se-Yong;Lee, Young-Woo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.10a
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    • pp.123-125
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    • 2008
  • Enamel layer consists of carbonated hydroxyapatite of 85%, water of 12% and protein of 3% and lipid and tentin consists of carbonated hydroxyapatite of 47%, water of 20% and protein of 33% and lipid so if heat is increased in teeth and then teeth color is discolor. In case high temperature is applied in teeth, teeth color changed quality is measured about change of time for minimize teeth change of color. Spectroscopic light intensity special quality by change of time rise at specification temperature.

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The Development of Grid Connecting Power Conditioning System for 250kW Fuel Cell Systems (250kW급 연료전지용 전력변환기 개발)

  • Jung Hong-Ju;Lee Jeong-Min;Chung Joon-Mo;Suh In-Young
    • Proceedings of the KIPE Conference
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    • 2006.06a
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    • pp.185-187
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    • 2006
  • 본 논문은 신 발전 방식들 중 하나인 용융탄산염형 연료전지 발전시스템의 국산화연구와 관련하여, 연료전지로부터 생성된 전력을 전력계통에 안정되게 변환, 주입하기 위한 계통연계형 전력변환기를 제작하고 단위기기별 성능 시험을 수행한 결과이다. 250kW급 전력변환기의 구조 설계와 단위기기 설계는 250kW급 용융탄산염형 연료전지 시스템의 정격 사양 및 스택의 운전 형태를 시뮬레이션 하여 진행되었으며, 크게 DC/DC 컨버터부와 DC/AC 인버터부의 회로로 구성된다.

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Carbonation of a few of Common materials which can fix CO2 (상용 CO2고정재료의 탄산화에 관한 문헌적 연구)

  • Chen, zheng-xin;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.10a
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    • pp.47-48
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    • 2016
  • Mineral carbonation technology is a process whereby CO2 is chemically reacted with calcium-and/or magnesium-containing minerals to form stable carbonate materials. Add the Materials that could fix CO2 as mineral admixture to concrete can improve the anti-carbonation properties of concrete. This paper has carried on the literature research on the carbonated mechanism of Material that could fix carbon dioxide. Such as Brucite, 𝜞-C2S, Mg2SiO4, MgO, Ca3MgSi2O8. And summarizes the development of the development of this field.

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Properties of Extruding Panel using Waste Concrete Powder with Mineral Carbonation as Silica Source (광물탄산화를 거친 폐콘크리트 미분말을 실리카 원료로 활용한 압출성형패널의 특성)

  • Choi, Hong-Beom;Kim, Kin-Man;Yu, Jae-Seong
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.13-14
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    • 2017
  • In this paper, research for use possibility as silica source of waste concrete powder discharged from direct and indirect carbonation has progressed. For the research, properties on the extruding panel using waste concrete powder with high silica content is evaluated. As the results, compressive strength of specimen is increased 24% compared to control specimen when waste concrete powder replaced 50%, that is discharged from carbonation process, as silica source.

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Fundamental Study on the CO2 gas Fixation Method using the Cement-Paste Solution's Calcium ion (시멘트 페이스트 수용액의 칼슘 이온을 이용한 CO2 가스 고정화에 관한 기초적 연구)

  • Kwack, Jae-Seok;Kang, Chang-Soo;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.05a
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    • pp.71-72
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    • 2012
  • The purpose of this study is not only fixation of carbon dioxide using the cement-Paste solution's calcium ion by wet carbonating reaction but also quantitatively evaluate the possibility of storage technology of Carbon dioxide. wet carbonation is reaction of CO2 injection by CO2 reactor. As a result of experiment, the carbon dioxide is fixed, and high-purity Calcium Carbonate is eluted.

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Acid/Base Buffer Capacity of Clays (점토의 산/염기 완충능)

  • 김건하;김길홍
    • Journal of the Korean Geotechnical Society
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    • v.16 no.6
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    • pp.97-103
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    • 2000
  • 지반내 중금속의 저류와 이동에 대한 가장 중요한 인자는 토양 간극수의 pH이다. 점토의 완충능을 kaolinite, hectorite, attapulgite, Na-bentonite와 같은 4가지 점토에 대하여 연구하였다. 완충능의 크기는 hectoriteattapulgite>kaolinite의 순으로 나타났다. 완충능의 크기는 지반내 탄산염 함량과 양이온 교환능력이 완충능의 크기에 가장 영향을 미치며 유기물 함량과 비표면적의 영향은 적었다. 토양의 완충능을 모델링하기 위하여 수소 이온과 토양표면의 화학반응 기간의 화학반응을 정전흡착 모델을 이용하여 모델링하였다. 또한 탄산염 함량과 양이온 교환능력을 함수로 하는 회귀식을 제안하였다. 모델 검증을 위하혀 모델 예측치와 실험치를 비교하였는데 정전 흡착모델을 이용한 예측치가 실험치와 근사한값을 나타냈다.

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An Analysis on the Performance and the Heat Transfer of Molten Carbonate Fuel Cell Stack (용융탄산염 연료 전지 스택의 성능 및 열전달 해석)

  • Koo, J.Y.;Suh, J.C.;Kim, Y.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.6 no.2
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    • pp.120-129
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    • 1994
  • A numerical investigation has been carried out for the electrochemical reaction, mass and heat transfer characteristics of the Molten Carbonate Fuel Cell(MCFC) stack. The effects of cooling air channel and water gas shift reaction were taken into account. The current density distribution of electrodes, the molecular fractions of reactant gasses and three dimensional temperature distribution can be calculated and shown by several lines of equivalent values. The results have been compared with the existing ones, and reasonable agreement has been obtained. To examine the influence of changing parameters, such as the composition of reactant gases, the target average current density, the utilization of reactant gases, the cooling air inlet temperature and flow rates, the computer simulation has been done. The analysis method and computer program developed in this study will be greatly helpful to design and verify the optimum operating condition of MCFC stack.

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$CO_2$ Gas Concentration Measurement and Modeling at a Classroom with Ventilation System of Middle School in Pusan (환기장치가 설치된 중학교 교실에서 탄산가스 농도변화 측정 및 모델링)

  • Kang, Tae-Wook
    • Journal of the Korean Solar Energy Society
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    • v.26 no.1
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    • pp.65-71
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    • 2006
  • This study describes to analyze variation of carbon dioxide gas concentration by experimental and theoretical method according to the using patterns of ventilation system in a model classroom. Concentration of $CO_2$ gas varied by the occupancy and the ventilation systems are operating or not. More than 850 CMH ventilation system can maintain $CO_2$ gas concentration lower than 1,000 ppm along the class time and can be adopted the government guideline. Theoretical modeling of the concentration was performed at well-mixed ideal condition. Delays of concentration decay were shown at each case compared to actual.

Studies on Synthesis of Magnesium Carbonate. II. Electronmicroscopic Shape of Magnesium Carbonate (탄산마그네슘의 제조연구 II 탄산마그네슘의 전자현미경적 고찰)

  • Rhee, Gye-Joo;Song, Churl;Sung, Nak-Won;Ahn, Yung-Pil
    • YAKHAK HOEJI
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    • v.15 no.1
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    • pp.32-40
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    • 1971
  • Optimum reactons for the preparation of extra-light magnesium carbonate from magnesium chloride and sodium carbonate solutions were found by observing the difference of crystalline shapes under an electromicroscope. Reaction temperature the and washing temperature were main factors affecting the crystalline shapes, and drying temperature was found to be of secondary importance. Optimum temperatures for reaction and washing ranged from $20^{\circ}C$ to $30^{\circ}C$ and the temperature over $40^{\circ}C$ should be avoided for the reaction and washing. It was found that the higher the drying temperature, the lighter the crsytal of the produced magnesium carbonate. Reaction time, molar ratio (Mg$^{2+}/CO_{3}^{2-}$ ) and the concentrations of magnesium chloride and sodium carbonate solutions have only a slight effect on the form of the product.

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