• 제목/요약/키워드: Emission unit

검색결과 451건 처리시간 0.027초

광중합의 시작, 어떤 광조사기를 어떻게 사용해야할까? (Clinical considerations in the use of dental light curing unit)

  • 이창하
    • 대한치과의사협회지
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    • 제57권3호
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    • pp.175-184
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    • 2019
  • Increasing the aesthetic needs of patients and decreasing the use of amalgam had led to increased demand for dental resin composite. Thereby, light curing unit (LCU) has become an essential equipment in dental clinic. To ensure long-term prognosis of photopolymerized materials, LCU should have a uniform and consistent radiant output and an emission spectrum that includes the active wavelength range of photoinitiators. In addition, when the correct use and thorough maintenance and repair of LCU are performed, the higher success rate of restoration using photopolymerization materials will be achieved.

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소비자 환경친화도 변화의 오염감축효과에 관한 소고(小考) (A Note on the Effects of the Greener Market on Pollution Emission)

  • 이호생
    • 자원ㆍ환경경제연구
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    • 제16권2호
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    • pp.363-378
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    • 2007
  • 환경친화적인 소비행태란 어떤 제품의 환경친화도가 높아지면 그 제품에 대한 지불용의도 커지는 것을 의미한다. 이러한 소비행태를 지닌 소비자들로 구성된 시장을 green market이라고 부른다. green market에 대한 거의 대부분의 기존 연구는 단위배출기준(unit emission standard), 환경세 등 환경정책수단의 효과를 분석하였다. 향후 소비자들의 환경친화적인 성향은 지속적으로 강화될 것이다. 이에 본 연구는 수직차별화 모형을 바탕으로 소비자 환경친화도의 변화가 오염물질 배출량에 미치는 영향을 고찰하였다. 본 연구에서 도출된 주요 결과는 다음과 같다. 먼저 제품의 필수재적인 성격이 강하여 모든 소비자들이 제품을 구매하는 경우에는 소비자들의 환경친화적인 성향이 높아지면 오염물질 배출량은 감소한다. 이는 소비자들의 환경친화도가 변화하여도 총생산량에는 아무런 변화가 없기 때문이다. 반면 일부 소비자들이 제품을 구입하지 않는 시장의 경우에는 환경친화적인 성향이 낮은 소비자들의 환경친화도가 상대적으로 크게 상승하면 오염물질 배출량이 증가할 수도 있다 이는 무엇보다도 환경친화적인 성향이 낮은 소비자들의 환경친화도가 상대적으로 크게 상승함에 따라 제품의 총생산량이 증가하기 때문이다.

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철골조 건물의 탄소배출량 산정을 위한 BIM 라이브러리 구축 (Establishment of CO2 Emission Estimation BIM Library for Steel Structures)

  • 이재철;정종현
    • 한국산학기술학회논문지
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    • 제15권5호
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    • pp.3169-3175
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    • 2014
  • 본 연구에서는 상용 BIM툴에서 기본적으로 제공하는 물량산출 기능을 활용해 탄소배출량을 산정하는 BIM 라이브러리 구축과정을 정립하고 이를 철골조 건물에 적용함으로써 그 타당성을 검증하였다. BIM 라이브러리는 요구되는 부재별 탄소배출계수를 설정한 후 매개변수를 추출하고 Revit Architecture 2013을 활용해 프로젝트 단위 설정, 매개변수 설정, 탄소 배출량 산정식 설정의 절차를 거쳐 구축하였다. 이를 통해 철골부재의 단면종류별 탄소배출계수와 단면크기별 단위무게를 입력해주는 것만으로 별도의 수작업 없이 투입자재량에 따른 탄소배출량을 산정해 낼 수 있음을 확인하였다. 본 연구에서 제시한 BIM 라이브러리 구축과정을 통해 부재별 탄소배출량 산정 라이브러리를 구축함으로써 시공단계의 투입자재량에 따른 탄소배출량을 손쉽게 산정할 수 있으며, 프로젝트 초기 설계단계에서 탄소배출량을 최소화 할 수 있는 설계대안의 선택에 일조함으로써 친환경적 건설사업 수행 및 BIM의 실무적 활용성 향상에 도움을 줄 수 있을 것으로 기대된다.

Poly(fluorene)s for LED Applications

  • Lee, Jeong-Ik;Zyung, Tae-Hyoung;Klaerner, Gerrit;Miller, Robert D.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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    • pp.129-130
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    • 2000
  • The emission color stability of poly(fluorene) derivatives upon thermal annealing or passage of current in an electroluminescent device is affected by the structure of the main chain polymer unit and particularly by the polymer chain end substituents. Proper attention to these features leads to colorfast blue emission in both photo- and electoluminescence. Furthermore, the spectral emission characteristics can be tuned by the incorporation of various comonomers. Preliminary single layer device studies validate the potential utility of poly(fluorene) homo and copolymers for OLED applications.

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Toward Efficacy Improvement in a PDP Discharge Cell from Structural Considerations

  • Tachibana, Kunihide
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.20-23
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    • 2009
  • The efficacy improvement issues in a unit discharge cell have been approached from the structural considerations. The tested cell designs include (a) a coplanar type with annular auxiliary electrode buried in barrier ribs, (b) a coplanar type with split auxiliary electrodes also burred in barrier ribs and (c) a coaxial type with a floating electrode stacked on the base electrode. From spatiotemporally resolved optical images of near-IR emission taken by a gated-ICCD camera and relative VUV emission intensity estimated by laser absorption spectroscopy, the differences in the discharge and light emission performances of those three cell types have been compared and discussed.

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An E-score Development Methodology for Life Cycle Impact Assessment

  • Young-Min Park;Jai-Rip Cho
    • 산업경영시스템학회지
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    • 제24권68호
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    • pp.51-65
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    • 2001
  • This study is to make LCIA(Life Cycle Impact Assessment) easier as a methodology of environmental scores(called E-score) that integrated environmental load of each emission substance based on environmental damage such as in human health, ecosystem and resources category. The concept is to analyzes the LCI(Life Cycle Inventory) and defines the level of environment damages for human health, ecosystem and resources to objective impact assessment standard, and makes the base of marginal damage to calculate the damage factor, which can present the indication that can establish the standard value of environmental impact. First, damages to human health are calculated by fate analysis, effect analysis and damage analysis to get the damage factor of health effect as a DALY(Disability Adjusted Life Years) unit. Second, damages to ecosystem are calculated by fate analysis, effect analysis and damage analysis to get the damage factor of the effect as a PDF(Potentially Disappeared Fraction) unit through linking potentially increased disappeared fraction. Third, damages to resources are carried out by resource analysis and damage analysis for linking the lower fate to surplus energy conception to get damage factor as a MJ(Mega Joule) unit. For the ranking of relative environment load level each other, LCIA can be carried out effectively by applying this E-score methodology to the particular emission substances. A case study has been introduced for the emission substances coming out of a tire manufacturer in Korea. It is to show how to work the methodology. Based on such study result, product-designers or producers now can apply the E-scores presented in this study to the substances of emission list, and then calculate the environment load of the product or process in advance at any time and can see the environment performance comparatively and expected to contribute to the environmental improvement in view of environmental pollution prevention.

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ISO 12219-5 (Static chamber법)를 이용한 모듈내 구성부품별 VOCs 영향도 분석 (VOCs impact factor analysis of unit components in Part assembly by ISO 12219-5 method)

  • 이신종;장혜진;곽동환;김만구
    • 분석과학
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    • 제27권6호
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    • pp.284-291
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    • 2014
  • 차량 실내 공기질 대응 프로세스는 두 단계의 시험 방법으로 이루어져 있다. 먼저 모듈 부품평가를 통해 차량 실내 VOCs의 주요 원인을 찾고, 절단 시험편을 이용하여 VOCs가 주로 방출되는 소재를 찾는다. 만약 VOCs가 주로 방출되는 소재를 확인 시, 소재 개선을 통해 차량과 모듈 부품에서 방출되는 VOCs를 줄일 수 있다. 하지만 기존의 절단 시험편을 이용한 시험법은 VOCs 원인을 찾는데는 절단면에서의 방출 문제가 있기 때문에, 구성 부품 단위의 평가방법 적용이 필요하다. ISO 12219-5 시험 방법은 부품 절단없이 평가를 하기 때문에 소재 및 표면적의 영향이 함께 고려되어, 모듈 부품에서 구성 부품의 VOCs 영향도 확인이 가능하였다. 트림과 콘솔의 구성부품 평가를 통해 모듈내의 주요 원인 부품을 확인할 수 있었다. 또한 ISO 12219-5 모듈 부품 시험법과 구성 부품 시험법간의 정량적 상관관계 규명을 통해 품질관리를 위한 관리값을 설정할 수 있었다.

연근해 자망과 통발 어업의 온실가스 배출량 현장실측 연구 (Comparative study of greenhouse gas emission from coastal and offshore gillnet and trap fisheries by field research)

  • 이석형;김현영;양용수;강다영
    • 수산해양기술연구
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    • 제54권4호
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    • pp.315-323
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    • 2018
  • Fossil fuel combustion during fishing activities is a major contributor to climate changes in the fishing industry. The Tier1 methodology calculation and on-site continuous measurements of the greenhouse gas were carried out through the use of fuel by the coastal and offshore gillnet (blue crabs and yellow croaker) and trap (small octopus and red snow crab) fishing boats in Korea. The emission comparison results showed that the field measurements are similar to or slightly higher than the Tier1 estimates for coastal gillnet and trap. In offshore gillnet and trap fisheries, Tier1 estimate of greenhouse gases was about $1,644-13,875kg\;CO_2/L$, which was more than the field measurement value. The $CO_2$ emissions factor based on the fuel usage was $2.49-3.2kg\;CO_2/L$ for coastal fisheries and $1.46-2.24kg\;CO_2/L$ for offshore fisheries. Furthermore, GHG emissions per unit catch and the ratio of field measurement and Tier1 emission estimate were investigated. Since the total catch of coastal fish was relatively small, the emission per unit catch in coastal fisheries was four to eight times larger. The results of this study could be used to determine the baseline data for responding to changes in fisheries environment and reducing greenhouse gas emission.

석유정제산업 공정과 공정장비에 기인한 휘발성 유해 대기오염물질(HAPs)의 배출량 산정기법 (Estimation Technique of Volatile Hazardous Air Pollutants(HAPs) Emitted from Petroleum Industrial Process/Equipment)

  • 조완근;권기동;동종인;강경희
    • 한국환경과학회지
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    • 제13권7호
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    • pp.703-710
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    • 2004
  • Petroleum refineries have been considered as an important emission source for atmospheric volatile hazardous air pollutants(HAPs). The emission source includes petroleum refinery processes and process equipment. The control strategy for volatile HAPs requires emission estimations of these pollutants. However, systematic methods of volatile HAPs emission from petroleum refineries have not yet been established. Accordingly, present study surveyed the estimation method of volatile HAPs emitted from the petroleum refinery processes and process equipment. The emission estimation methods for the petroleum refinery processes are applied for 11 petroleum refining facilities: fluidized catalytic cracking, thermal cracking, moving bed catalytic cracking, compressed engine, blowdown system, vacuum distilled column condensator, natural gas or distilled boiler, natural gas or distilled heater, oil boiler, oil heater and flare. Four emission estimation methods applied for the petroleum refinery process equipment are as follows: average emission factor approach, screening ranges approach, EPA correlation approach and unit-specific correlation approach. The process equipment for which emission factors are available are valves, pump seals, connectors, flanges and open-ended lines.

Design of partial emission type liquid nitrogen pump

  • Lee, Jinwoo;Kwon, Yonghyun;Lee, Changhyeong;Choi, Jungdong;Kim, Seokho
    • 한국초전도ㆍ저온공학회논문지
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    • 제18권1호
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    • pp.64-68
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    • 2016
  • High Temperature Superconductor power cable systems are being developed actively to solve the problem of increasing power demand. With increases in the unit length of the High Temperature Superconductor power cable, it is necessary to develop highly efficient and reliable cryogenic pumps to transport the coolant over long distances. Generally, to obtain a high degree of efficiency, the cryogenic pump requires a high pressure rise with a low flow rate, and a partial emission type pump is appropriate considering its low specific speed, which is different from the conventional centrifugal type, full emission type. This paper describes the design of a partial emission pump to circulate subcooled liquid nitrogen. It consists of an impeller, a circular case and a diffuser. The conventional pump and the partial emission pump have different features in the impeller and the discharge flow passage. The partial emission pump uses an impeller with straight radial blades. The emission of working fluid does not occur continuously from all of the impeller channels, and the diffuser allows the flow only from a part of the impeller channels. As the area of the diffuser increases gradually, it converts the dynamic pressure into static pressure while minimizing the loss of total pressure. We used the known numerical method for the optimum design process and made a CFD analysis to verify the theoretical performance.