• 제목/요약/키워드: Atmospheric composition

검색결과 411건 처리시간 0.059초

질산이온 선택성 피복선 전극의 제작 및 환경분석에의 응용 (Preparation of Coated-Wire Nitrate Ion Selective Electrode and its Application for Environmental Analysis)

  • 李龍根;金昌圭;朴廷泰;金京燮;黃圭子
    • 한국대기환경학회지
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    • 제1권1호
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    • pp.99-107
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    • 1985
  • A coated wire ion selective electrode for nitrate (nitrate-CWE_ was constructed using epoxy resin, ion exchanger and plasticizer as a polymer membrane. It's stility, the composition of a polymer membrane, the response characteristics, the selectivity were examined and applied to the environmental analysis. The nitrate-CWE was prepared using a copper wire, wihch was coated with epoxy resin being incorporated with the nitrate ion exchanger and plasticizer. The best composition of the polymer membrane for the nitrate-CWE was obtained by mixing epoxy resin, ion exchanger and plasticizer in the ratio of 2:1:0.4. The potential (56.3$\pm$0.5 mV) of stick form nitrate-CWE in this composition was close to that (59.2 mV) of Nernstian response. The detection limit for nitrate ion were found to the about $6 \times 10^{-5}M$ and the useful pH was 2.5 $\sim$ 10.3. Furthermore, the selectivity of iodide and perchrorate for the nitrage-CWE was also much improved compared with that for a liquid membrane nitrate electrode. The nitrate-CWE was used to determind $NO_x$ in stack gas. The results were in good agreement with those obtained either by electrode method or by the improved NEDA method within a relative error of 4.0%.

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대기 에어로졸의 체류시간과 화학조성 I. 부산지역에서 주요이온과 중금속의 농도 (Residence Times and Chemical Composition of Atmospheric Aerosols I. Concentration of Major Ions and Heavy Metals in Pusan)

  • 양한섭;전은주;김영일;옥곤
    • 한국환경과학회지
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    • 제8권1호
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    • pp.51-59
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    • 1999
  • Chemical composition of atmospheric aerosols was measured at 4 sites in Pusan. All the samples were collected with a high volume air sampler from January to October 1996, to analyze major ions and heavy metals. Dominant ions of aerosols were S $O_4$$^{2-}$ in anion and N $a^{+}$ in cation. Sulfate, nitrate and ammonium ions in aerosols showed high enrichment factor to soil and seawater composition. The concentrations of heavy metals in aerosols was lowest at the site PI near the coast. The lowest concentrations of major ions and heavy metals mainly appeared in August, probably due to scavenging by frequent rains. Especially, the concentrations of total suspended particulate matter(TSP) and heavy metals in aerosols showed good correlations in Pusan. Based on crustal Al, enrichment factors for some metals(Zn, Cu, Pb, Cd) in aerosols were significantly greater than unity, and the order was Cd > Pb > Zn > Cu. This evidence suggests that Cd and Pb are derived predominantly from non-crustal sources.s.

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Measurement and Estimation of VOC Composition from Gasoline Evaporation

  • Na, K.;Moon, K.-C.;Kim, Y.P.
    • Journal of Korean Society for Atmospheric Environment
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    • 제17권E3호
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    • pp.101-107
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    • 2001
  • Source profiles were developed for a total of 45 volatile organic compounds (VOC) that can be emitted from gasoline evaporation. The gasoline samples of five major brands (for each season) were blended on the basis of the market share in Seoul area and analyzed by a GC-MS/FID system. In addition, we calculated gasoline evaporative compositions using the Raoult's law from the liquid gasoline compositions. The measured and estimated gasoline vapor compositions agree well each other. As a group, alkanes are the most abundant in the gasoline vapors profiles (77.4% on average), followed by alkenes (19.1%), and aromatics (1.7%). As a specie in gasoline vapor, i-pentane is the most abundant, followed by n-butane, n-pentane, i-butane, trans-and cis-2-butenes, 2-methyl-2-butene, and trans-and cis-2-pentenes . It was also seen that aromatic content was much lower in the vapor phase compositions. From the comparison between experimental and calculated compositions, we identified the fact that once the gasoline vapor composition is reliably constructed entirely from the measured gasoline composition and the Raoult's law calculations, the need for doing separate chemical analyses of the gasoline vapor can be reduced.

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저압 임팩터를 이용한 대기 에어로졸 입자의 입경분포 측정과 화학조성 자료의 해석 (Characterization of Chemical Composition and Size Distribution of Atmospheric Aerosols by Low-Pressure Impactor)

  • 박정호;최금찬
    • 한국대기환경학회지
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    • 제13권6호
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    • pp.475-486
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    • 1997
  • The characteristics of atmospheric aerosols were investigated as a function of particle size and water solubility. The atmospheric aerosols were sampled with classifying into 12 size ranges by the use of Andersen low-pressure impactor. Collected aerosol particles were extracted by ultrapure water and filtered to be separated into water-soluble and insoluble components. The concentrations 12 elements in both components were determined by PIXE analysis. And the concentrations of 8 ions in the soluble component were analyzed by ion chromatography. In general, the mass size distribution of particulate matter was represented as a bimodal distribution. The mass size distributions of S$(SO_4^{2-}), K(K^+), Zn and NH_4^+$ skewed to the smaller size range and those of Si, Ca$(Ca^{2+}), Fe, Na^+ and Mg^{2+}$ skewed to the larger size range. They had roughly one peak in the fine and coarse particle region,respectively. On the other hand, the mass size distribution of Ti, Mn, Ni, Cu, $Cl^- and NO_3^-$ were represented as the bimodal distribution. Fe and Si in the aerosol particles extracted into pure water are existing in high insoluble state. Conversely, almost the whole of S is dissolved in water.

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대형천연가스차량에서 촉매시뮬레이션에 의한 배출가스의 변환율 예측 연구 (A Conversion Rate Prediction Study of Exhaust Gas by Catalyst Simulation in Heavy Duty Natural Gas Vehicle)

  • 한영출;오용석;강호인
    • 한국대기환경학회지
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    • 제16권3호
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    • pp.257-264
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    • 2000
  • An aftertreatment device which reduce exhaust gas of natural gas vehicle(NGV), NGV catalyst has important meaning as to reduce the exhaust emission. In this study, the characteristics of NGV catalyst were investigated and the effect parameters of NGV catalyst were analyzed and were predicted by changing the various parameters such as temperature, and gas concentration. The conversion efficiency of NGV catalyst converter was also predicted by Pd-loading, mass flow rate and gas composition.

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황사기간중 제주지역의 에어로졸과 수용성이온의 크기분포 (Study on Size Distribution of Total Aerosol and Water-soluble tons During an Asian Dust Storm Event at Jeju Island)

  • Park Seong-Hun;Song Chang-Byeong;Kim Min-Cheol;Gwon Sun-Park;Lee Gyu-Won
    • 한국대기환경학회:학술대회논문집
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    • 한국대기환경학회 2002년도 춘계학술대회 논문집
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    • pp.159-160
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    • 2002
  • Soil dust particles transported from loess regions of the Asian continent, called Asian dust, highly influences the air quality of north-eastern Asia and the northern Pacific Ocean. The effects of these dust storms, on the chemical composition of atmospheric aerosol particles with different size, was investigated. Measurements of size distributions of total aerosol and major ion species were carried out on Jeju Island, Korea. (omitted)

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황사/비황사의 입자 조성 변화: 1993~1996년 봄철 고산 측정자료 (Aerosol Composition Change due to Yellow)

  • 박민하;김용표;강창희
    • 한국대기환경학회지
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    • 제17권6호
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    • pp.487-492
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    • 2001
  • In this technical information, the springtime TSP measurement data between 1993 and 1996 at Kosan are presented. Based on the data, it was found that the concentrations of crustal species increase when Yellow Dust phenomenon occurs. Among anthropogenic species, the concentration of Pb and NO$_3$$^{[-10]}$ increase when Yellow Dust phenomenon occurs. Further research agenda are discussed to study the effects of Yellow Dust.

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Understanding of Non-Thermal Atmospheric Pressure Plasma Characteristics Produced in Parallel Plate Type Geometry

  • Choe, Wonho;Moon, Se Youn;Kim, Dan Bee;Jung, Heesoo;Rhee, Jun Kyu;Gweon, Bomi
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.144-144
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    • 2013
  • Non-thermal atmospheric pressure plasmas have recently garnered much attention due to their unique physical and chemical properties that are sometimes significantly different from those of low pressure plasmas. It can offer many possible application areas including nano and bio/medical areas. Many different types of plasma sources have been developed for specific needs, which can be one of the important merits of the atmospheric pressure plasmas since characteristics of the produced plasma depend significantly on operating parameters such as driving frequency, supply gas type, driving voltage waveform, gas flow rate, gas composition, geometrical factor etc. Among many source configurations, parallel plate type geometry is one of the simplest configurations so that it can offer many insights for understanding basic underlying physics. Traditionally, the parallel plate type set up has been studied actively for understanding low pressure plasma physics along with extensive employment in industries for the same reason. By considering that understanding basic physics, in conjunction with plasma-surface interactions especially for nano & bio materials, should be pursued in parallel with applications, we investigated atmospheric pressure discharge characteristics in a parallel plate type capacitive discharge source with two parallel copper electrodes of 60 mm in diameter and several millimeters in gap distance. In this presentation, some plasma characteristics by varying many operating variables such as inter-electrode distance, gas pressure, gas composition, driving frequency etc will be discussed. The results may be utilized for plasma control for widening application flexibility.

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