• 제목/요약/키워드: candle

검색결과 118건 처리시간 0.022초

촛불 실험과 관련된 오개념 교정을 위한 지도방안 탐색 (Exploration of the teaching method for the prescription of the misconceptions on the Candle Experiment)

  • 전우수
    • 한국초등과학교육학회지:초등과학교육
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    • 제18권2호
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    • pp.145-151
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    • 1999
  • There is an experiment in the elementary science textbook which a burning candle hold upright in a water tank and a beaker is converted over the burning candle, the candle flame goes out and the water rises into the beaker. Some reference books including teachers' guide for the elementary school teachers explain the reason why water rises that oxygen is "used up", so water rises the same volume of consumed oxygen into the beaker. But this explanation is only partially correct. In this study, discrepancies of the explanation that oxygen is "used up" are analyzed. Water rises by two major reasons. One is that water can rise to the level about l/3 of the volume of consumed oxygen. The other is that the beaker is converted over the burning candle which produces hot CO2 and water vapor, and the candle's flame heats the air around it to expand, after the candle flame goes out, the air in the beaker cools and water vapor changes to liquid water, so, air pressure in the beaker is reduced, and the water is pushed into the beaker by great air pressure outside. 1 demonstrate a inquiry teaching method of the candle experiment.

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Forecasting Symbolic Candle Chart-Valued Time Series

  • Park, Heewon;Sakaori, Fumitake
    • Communications for Statistical Applications and Methods
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    • 제21권6호
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    • pp.471-486
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    • 2014
  • This study introduces a new type of symbolic data, a candle chart-valued time series. We aggregate four stock indices (i.e., open, close, highest and lowest) as a one data point to summarize a huge amount of data. In other words, we consider a candle chart, which is constructed by open, close, highest and lowest stock indices, as a type of symbolic data for a long period. The proposed candle chart-valued time series effectively summarize and visualize a huge data set of stock indices to easily understand a change in stock indices. We also propose novel approaches for the candle chart-valued time series modeling based on a combination of two midpoints and two half ranges between the highest and the lowest indices, and between the open and the close indices. Furthermore, we propose three types of sum of square for estimation of the candle chart valued-time series model. The proposed methods take into account of information from not only ordinary data, but also from interval of object, and thus can effectively perform for time series modeling (e.g., forecasting future stock index). To evaluate the proposed methods, we describe real data analysis consisting of the stock market indices of five major Asian countries'. We can see thorough the results that the proposed approaches outperform for forecasting future stock indices compared with classical data analysis.

발광다이오드를 이용한 디지틀 캔들 개발 (Development on the Digital Candle Using LED)

  • 소병문;강성준;오성훈;이동휘
    • 한국산학기술학회논문지
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    • 제11권11호
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    • pp.4291-4295
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    • 2010
  • 본 논문은 독립적으로 발광다이오드의 캔들 컬러를 제어하는 발광다이오드 조명 데코레이션 시스템을 제안한다. 적색, 녹색, 청색 발광다이오드를 사용하여 발광다이오드 캔들 제어에 제안된 프로세스를 적용하였으며 캔들에 발광다이오드와 광섬유를 적용하여 스위치 부품을 사용하지 않고 캔들 내부의 광원을 발광시키는것이 가능하여 개발 결과를 상용화 하고자 한다.

산화구리 촉매담지 세라믹 캔들필터를 이용한 NO 제거 (Removal of NO Using CuO/3Al2O3 · 2SiO2 Catalyst Impregnated Ceramic Candle Filters)

  • 홍민선;문수호;이재춘;이동섭
    • 한국대기환경학회지
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    • 제20권3호
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    • pp.291-302
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    • 2004
  • The CuO/$3AL_2O_3{\cdot}2SiO_2$ catalyst impregnated ceramic candle filters for nitrogen oxides removal were prepared by porous mullite($3AL_2O_3{\cdot}2SiO_2$) support and CuO catalyst deposited on this support to achieve uniformly dispersed CuO deposition, which are impregnated into the pores of available alumino-silicate ceramic candle filter. The CuO/3$AL_2O_3{\cdot}2SiO_2$ catalyst impregnated ceramic candle filters were characterized by XRD, BET, air permeability, pore size, SEM and catalytic tests in the reduction of NOx by NH$_3$. The observed effects of CuO/3$AL_2O_3{\cdot}2SiO_2$ impregnated ceramic candle filters in SCR reaction are as follows : (1) when the content of CuO catalyst increased further, activity of NO increased. (2) NO conversion at first increased with temperature and then decreased at high temperatures (above 40$0^{\circ}C$), possibly due to the occurrence of the ammonia oxidation reaction. (3) In pilot plant test for 3 months, NO conversion was greater than 90%.

촛불화재사례 및 재현실험을 통한 화재예방대책 연구 (A Study on Fire Prevention Measures through Candle Fire Case and Reproduction Experiment)

  • 이정일;김영수
    • 한국재난정보학회 논문집
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    • 제15권1호
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    • pp.12-19
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    • 2019
  • 연구목적: 촛불화재는 매년 같은 유형으로 반복되어 사상자가 발생하고 있기에 화재조사결과를 바탕으로 주로 발생되는 형태를 재현실험을 통해 분석하여 동종의 화재를 줄이는데 목적이 있다. 연구방법: 촛불화재 분석을 위해 아크릴 재연실험, 포멕스(FOMEX) 아크릴 재연실험, 일반가연물 재연실험, 촛불의 자연소화 재연실험 등 4가지 방법으로 실시하였다. 연구결과: 주변에 가연물의 접촉이 없으면 지속적인 연소가 이루어지기가 힘들다는 것을 확인하였다. 결론: 촛불화재를 예방하기 위해서는 주변 안전확인이 무엇보다 중요하며 초 말단에 은박지와 같은 불연 재료로 마감 처리하는 등 안전규정을 도입하는 것도 하나의 방법이라고 생각한다.

바나디아 촉매담지 세라믹 캔들필터를 이용한 질소산화물 제거기술 (Removal Technology of NOx Using V2O5/TiO2 Catalyst Impregnated Ceramic Candle Filters)

  • 이동섭;박진식
    • 한국환경과학회지
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    • 제16권9호
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    • pp.1077-1083
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    • 2007
  • [ $V_2O_5/TiO_2$ ] catalyst impregnated ceramic candle filters are in principle, capable of performing shallow-bed dust filtration plus a catalytic reaction, promoted by a catalytic deposited in their inner structure. Pilot-scale $V_2O_5/TiO_2$ catalyst impregnated ceramic candle filters were prepared, characterized and tested for their activity towards the SCR reaction. The effect on NO conversion of operating temperature, gas hourly space velocity, amount of deposited catalyst, pressure drops and long-term experiment (life of catalytic filter) was determined. The following effects of $V_2O_5/TiO_2$ catalyst impregnated ceramic candle filters in SCR reaction are observed: (1) It increases the activity and widens the temperature window for SCR. (2) When the content of $V_2O_5$ catalyst increases further from 3 to 9wt.%, activity of NO increases. (3) NO conversion at first increases with temperature and then decreases at high temperatures (above $400^{\circ} over), possibly due to the occurrence of the ammonia oxidation reaction.

세라믹캔들필터 집진 전후 Ash의 크기 및 분포에 관한 연구 (A study on Ash size and its distribution on cleaning of ceramic candle filter)

  • 정진도;이중범;김종영
    • 대한기계학회논문집B
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    • 제20권5호
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    • pp.1639-1648
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    • 1996
  • Protection of gas turbine blade from its erosion and abrasion at high temperature and pressure is the first goal to cleanup the hot gas upstream for IGCC and PFBC. Ceramic filters represent an attractive technology for particle removal at high temperature and high pressure condition. They have demonstrated being a good system for improvement of thermal efficiency and reduction of effluent pollutants in advanced coal-based power systems such as IGCC and PFBC. Ceramic filter elements currently being developed were evaluated in the previous paper. In this paper, we measured the ash size and distribution on cleaning of ceramic candle filter. The results are as follows : in this experimental range, ceramic candle filter was shown to be fully adequate for the removal process of dust under high temperature and pressure. Also filtration efficiency of ceramic candle filter was higher than 98% compared with the regulation limit of particle size in gas turbine inlet.

Performance of a Group Candle Filter in a Hot Bench Unit

  • Park, Joo-Hong;Park, Gyung-Won
    • 에너지공학
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    • 제8권1호
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    • pp.143-149
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    • 1999
  • The mounting technology of ceramic candle elements utilizing disk spring was tested in a hot bench unit. Seven SiC candle elements were fixed in three groups by 2, 2, and 3 elements per group. And its performance was investigated in a hot gas stream using oil burned-exhaust gas. The experimental results showed that this mounting method gave a good performance enough to be useful for the particulate removal in the integrated gasification combined cycle (IGCC). Some operational characteristics of the groupfilter were observed.

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진공 압출성형 및 래밍성형 공정에 의한 탄화규소 캔들 필터 제조 및 특성 (II) (Fabrication and Properties of SiC Candle Filter by Vacuum Extrusion and Ramming Process (II))

  • 한인섭;서두원;김세영;홍기석;우상국;김영욱
    • 한국세라믹학회지
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    • 제47권6호
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    • pp.515-523
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    • 2010
  • Porous SiC candle filter preforms were fabricated by extrusion and ramming process. To fabricate SiC candle filter preform, commercially available F180 mesh ($85\;{\mu}m$) $\alpha$-SiC powder and $44\;{\mu}m$ mullite, $CaCO_3$ powder were used as the starting materials. The candle type preforms were fabricated by vacuum extrusion and ramming process, and sintered at $1400^{\circ}C$ 2 h in air atmosphere. Corrosion test of the sintered candle filter specimens as forming method was performed at $600^{\circ}C$ for 2,400 h in simulated IGCC syngas atmosphere. The effect of forming method on mechanical properties, pore distribution, microstructure and crystalline phase was investigated.

진공 압출성형 및 래밍성형 공정에 의한 탄화규소 캔들 필터 제조 및 특성 (Fabrication and Properties of the SiC Candle Filter by Vacuum Extrusion and Ramming Process)

  • 신명관;한인섭;서두원;김세영;우상국;이승원;김영욱
    • 한국세라믹학회지
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    • 제46권6호
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    • pp.662-667
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    • 2009
  • Porous SiC candle filter preforms were fabricated by extrusion and ramming process. To fabricate SiC candle filter preform, commercially available 85 ${\mu}m\;{\alpha}-$-SiC powder and 44 ${\mu}m$ mullite, CaC$O_3$ powder were used as the starting materials. The candle type preforms were fabricated by vacuum extrusion and ramming process, and sintered at $1400{^{\circ}C}$ 2 h in air atmosphere. The effect of forming method on porosity, density, strength (flexural and compressive strength) and microstructure was investigated. Also, corrosion test of the sintered candle filter specimens as forming method was performed at $600{^{\circ}C}$ in IGCC syngas atmosphere. The sintered SiC filter which was formed by ramming process has more higher density and exhibit higher strength than extruded filter. Its maximum density and 3-point bending strength were 2.00 g/$cm^3$ and 45 MPa, respectively.