• 제목/요약/키워드: Flameless

검색결과 54건 처리시간 0.024초

불꽃 및 비불꽃원자흡수분광법을 이용한 뇨중 카드뮴 분석 (Analysis of Cadmium in Urine using Flame and Flameless Atomic Absorption Spectrophotometry)

  • 함용규;이석기;전해홍;정창웅;손부순
    • 분석과학
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    • 제12권5호
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    • pp.355-359
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    • 1999
  • 뇨중 미량 카드뮴 분석에 흑연로 장치가 부착된 원자흡수분광광도계(GFAAS)를 사용하였다. 불꽃분광법에서 시료는 회화하여 Na-DDTC로 착물을 형성한 후 MIBK로 추출하였으며, 비불꽃분광법에서는 1% Triton X-100과 1% $HNO_3$으로 5배 희석시킨 후 $Pd(NO_3)_2$를 매트릭스 개선제로 농도를 변화시키면서 회화 온도 $450-750^{\circ}C$에서 pyrocoated 흑연 튜브를 사용하여 분석하였다. 그 결과 불꽃분광법보다는 비불꽃분광법이 전처리가 간단하고 재현성있게 나타났으며, 비불꽃분광법을 이용한 경우 $Pd(NO_3)_2$ 100 mg/L을 사용하여 회화온도 $550^{\circ}C$에서 분석시 가장 높은 흡광도를 나타냈다. 본 분석법을 표준뇨인 Lononorm-Metalle 3 중의 카드뮴 분석에 적용하였다.

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산림 화재감식 응용을 통한 내화림 조성에 관한 연구 (A Study on the Afforestation of Fire-Resistant Forest through an Application of Forest Fire Investigation)

  • 박영주
    • 한국안전학회지
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    • 제26권5호
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    • pp.118-129
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    • 2011
  • In this study, species resistant to forest fire were extracted from high trees through an investigation of combustion mechanism. Here, the average flameless ignition temperatures of living leaves, branches and barks of oak were respectively, $365^{\circ}C$, $440^{\circ}C$ and $435^{\circ}C$, and the average flameless ignition temperatures of living leaves, branches, barks and cones of pine tree were respectively, $320^{\circ}C$, $405^{\circ}C$, $435^{\circ}C$ and $363^{\circ}C$. It shows that generally, pine tree has a lower flameless ignition temperature than oak and thus, has a relatively high risk of flameless ignition. When comparing risk of fire depending on ignition characteristics, Quercus serrata had a low risk of stem fire, and Quercus acutissima and Quercus serrata had a low risk of crown fire, as well. When analysing risk of fire depending on a duration of flame, also, Quercus dentata had a low risk of stem fire, and Quercus variabilis Blume had a low risk of crown fire too. Lastly, when comparing risk of fire, according to heat release rates, Quercus acutissima had a low risk of stem fire, and Quercus acutissima and Quercus dentata had a low risk of crown fire, as well. In conclusion, it was observed that as fire-resistant species, Quercus serrata and Quercus dentata have a low risk of ignition, Quercus variabilis Blume has a short duration of flame after discharging ignition when a forest fire occurs, and Quercus acutissima, Pinus Rigida and Antipathes japonica Brook have low heat release rates.

자기축열식 저 NOx 연소기에서 배가스 재순환이 연소특성에 미치는 영향 (The Effect of Flue-gas Recirculation on Combustion Characteristics of Self Regenerative Low NOx Burner)

  • 강민욱;김종규;동상근;윤영빈
    • 한국연소학회지
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    • 제8권1호
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    • pp.17-24
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    • 2003
  • The conventional regenerative system has a high thermal efficiency as well as energy saving using the high preheated combustion air. in spite of these advantages, it can not avoid high nitric oxide emissions. Recently, flameless combustion has received much attention to solve these problems. In this research, numerical analysis is performed for flow-combustion phenomena in the self regenerative burner. In this analysis we used Fluent 6.0 code. the that is developed for commercial use, Methane gas is used as a fuel and two-step reaction model for methane and Zeldovich mechanism for NO generation are used. the velocity of the preheated combustion air is used as a parameter and we analyze the characteristics of flow-field, temperature distributions and NO emissions. Due to the increased recirculation rate, the maximum temperature of flame is significantly increased and NOx emissions is reduced.

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축열식 저 NOx 연소기의 배가스 재순환이 연소특성에 미치는 영향 (The effect of flue-gas recirculation on combustion characteristics of regenerative low NOx burner)

  • 강민욱;윤영빈;동상근
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2002년도 제25회 KOSCI SYMPOSIUM 논문집
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    • pp.97-104
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    • 2002
  • The conventional regenerative system has a high thermal efficiency as well as energy saving using the high preheated combustion air. in spite of these advantages, it can not avoid high nitric oxide emissions. Recently, flameless combustion has received much attention to solve these problems. In this research, numerical analysis is performed for flow-combustion phenomena in the self regenerative burner. In this analysis we used Fluent 6.0 code. the that is developed for commercial use, Methane gas is used as a fuel and two-step reaction model for methane and Zeldovich mechanism for NO generation are used. the velocity of the preheated combustion air is used as a parameter and we analyze the characteristics of flow-field, temperature distributions and NO emissions. Due to the increased recirculation rate, the maximum temperature of flame is significantly increased and NOx emissions is reduced

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FAAS를 이용한 혈중 Cisplatin의 분석법 개발 (The Development of Cisplatin Analysis Method in Plasma by Flameless Atomic Absorption Spectrometry)

  • 백만정;임호섭;정미진;이경옥;신호상
    • 분석과학
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    • 제11권4호
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    • pp.243-247
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    • 1998
  • 백금을 함유한 항암제로 신장과 신경계에 심각한 부작용을 일으키는 cisplatin의 혈중 농도를 flameless atomic absorption spectrometry법(FAAS)으로 분석하였다. 이 방법은 시료전처리 과정이 필요 없어 신속하고 간단한 분석법이다. 검정곡선에 대한 직선성을 조사한 결과 20~1000ng/mL 농도 범위에서 r=0.999로 나타났으며, 정확도는 50 ng/mL 이상의 농도에서 상대표준편차가 5.0% 이하 이었다. 그리고, 혈장시료 $200{\mu}L$에 대한 검출한계는 10 ng/mL 이었다. 본 방법은 cisplatin의 최적 치료 조건과 독성 경감을 위한 혈중 모니터링에 그 활용이 크게 기대된다.

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도금업 근로자의 혈청과 공기중 크롬 및 니켈 농도 (Chromium and nickel concentrations in air and in serum of workers in chromium and nickel electroplating plants)

  • 최호춘;김해정;정호근
    • 한국산업보건학회지
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    • 제1권2호
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    • pp.117-127
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    • 1991
  • The exposure level of chromium and nickel for chrome and nickel plating workers were evaluated. Chromium and nickel concentrations in serum from 82 exposed workers and 66 controls, who were not exposed occupationally to metals, were analyzed by flameless atomic absorption spectrophotometry. The results were as follows : 1. The recovery percent of chromium and nickel concentrations in personal air samples were 95-108.2%, 88.0-107.7%, precisions (C.V., %) were 2.7-3.1%, 2.1-4.4%. respectively. 2. The recovery percent of chromium and nickel concentrations in serum were 93.6-106.4%, 91.3-107.9% and precisions (C.V. %) were 1.1-7.6%, 2.4-5.4% respectively. 3. The exposure level of chromium and nickel concentrations in the place of preparation process were $2.0{\pm}2.00{\mu}g/m^3$, chromplating were $35.7{\pm}53.07{\mu}g/m^3$, $2.8{\pm}3.42{\mu}g/m^3$, nickelplating were $4.6.0{\pm}5.8{\mu}g/m^3$, $18.62{\pm}4.41{\mu}g/m^3$, and covering were $2.9{\pm}2.02{\mu}g/m^3$, $1.1{\pm}0.47{\mu}g/m^3$ respectively. There were significant difference of concentrations for chromium and nickel in workplaces by groups statistically. 4. Chromium concentrations in serum of exposed group and control were $0.68{\pm}0.399{\mu}g/l$, $1.41{\pm}0.748{\mu}g/l$, respectively. There were significant difference of concentrations for chromium and nickel in serum by groups statistically. 5. Chromium and nickel concentrations in serum of exposed group were not significant by workplaces.

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Mild Combustor의 연소특성 해석 (Numerical Study on Characteristics of Mild Combustion)

  • 김군홍;강성모;김용모
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 제26회 KOSCO SYMPOSIUM 논문집
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    • pp.215-222
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    • 2003
  • Mild combustion or Flameless oxidation(FLOX) have been considered as one of the most prospective clean-combustion technologies to meet both the targets of high process efficiency and low pollutant emissions. A mild combustor with high air preheating and strong internal exhaust gas recirculation is characterized by relatively low flame temperature, low NOx emissions, no visible flame and no sound. In this study, the Steady Flamelet Approach has been applied to numerically analyze the combustion processes and NOx formation in the mild combustor. The detailed discussion has been made for the basic characteristics of mild combustor, numerical results and limitation of the present combustion modeling.

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