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        검색결과 149

        144.
        1999.08 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to investigate the characteristics of removal efficiency for aromatic hydrocarbons using a high-temperature fiber filter on a laboratory scale. The main elemental compositions of a high-temperature fiber filter are aluminium and silica, which can act as the catalysts. Benzene, toluene and o-xylene among aromatic hydrocarbons were used in this experiment. For 3㎝ thickness of fiber filter, these compounds were removed more than 90% at the face velocities of 3㎝/sec and 5㎝/sec above 450℃. For 4㎝ thickness of it, the removal efficiencies of these compounds were almost 90% from 400℃ at the same face velocities, suggesting that it may be due to increasing the contact time between the fiber filter and aromatic hydrocarbons. The pressure drop ranged from 22 to 48㎜H2O for 3㎝ thickness of fiber filter. However, for 4㎝ thickness of it, it was about two times(41-89㎜H2O) higher than that for 3㎝ fiber thickness.
        145.
        1998.10 KCI 등재 서비스 종료(열람 제한)
        The volatile organic compounds(VOCs) emitted from raw garlic and Kimchee were analyzed with thermal desorption or purge & trap/gas chromatography/mass selective detection method. Very offensive compounds such as methyl allyl sulfide, dimethyl sulfide, dimethyl disulfide, diallyl sulfide, methyl allyl disulfide, diallyl disulfide and dimethyl trisulfide were detected, and among them, dimethyl disulfide and dimethyl trisulfide were confirmed to be generated during the precocity of Kimchee or emitted from the stuff of Kimchee other than the garlic. Malodorous compounds emitted from the garlic or Kimchee were detected in the breath of a Korean and the refregirator keeping Kimchee. It was confirmed that the disufides emitted from the garlic or Kimchee were major components of offensive odor in the alveolar air and the refregirator. It was clarified that heat process is very effective to reduce odorous VOCs in garlic or Kimchee.
        146.
        1996.12 KCI 등재 서비스 종료(열람 제한)
        In order to grasp a characterization of low boiling point chlorinated organic compounds, this study which were carried out at the 8 stations for precipitation samples in the Pusan area during the period from February to September 1995. As a result, low boiling chlorinated organic compounds were estimated that it was dissolved by a portion of precipitation, and it be able to shift at the surface of the each. Concentration of low boiling point chlorinated organic compounds in precipitation are increased with increase of temperature, and estimated that air pollution compounds of as a rule in atmosphere.
        147.
        1995.12 KCI 등재 서비스 종료(열람 제한)
        Volatile organic compounds(VOCs) are of concern for their potential chronic toxicity, their suspected role in the formation of smog, and their suspected role in destruction of stratospheric ozone. Present study evaluated the exposures to selected VOCs in three microenvironments: 2 chlorinated and 5 aromatic VOCs in the indoor and outdoor air, and 5 aromatic VOCs in the breathing zone air of gas-service station attendants. With permissible Quality Assurance and Quality Control performances VOC concentrations were measured 1) to be higher in indoor air than in outdoor air, 2) to be higher in two Taegu residential areas than in a residential area of Hayang, and 3) to be higher in the nighttime than in the daytime. Among five aromatics, Benzene and Toluene were two most highly measured VOCs in breathing zone air of service station attendants. Based on the sum of VOC concentrations, the VOC exposure during refueling was estimated to be about 10% of indoor and outdoor exposures. For Benzene only, the exposure during refueling was estimated to cause about 52% of indoor and outdoor exposure. The time used to calculate the exposures was 2 minutes for refueling and 24 hours for indoor and outdoor exposures.
        148.
        1992.07 KCI 등재 서비스 종료(열람 제한)
        To perform a long-term ambient sampling study at a residential site, an air sampler was constructed to collect 24-hour integrated air samples suitable for the volatile organic compounds (VOCs) analysis. It includes an esthetically acceptance due to proximity to homes, as well as providing the required sampling specifications. The VOCs sampler accomodates four 5/8 stainless steel(SS) traps packed with adsorbent(Tenax) and is capable of four flow rates in the range of 5 to 50 cc/min. Sintered metal filters(10 micrometer) were directly connected to the inlet of the trap adapters. Additional specifications include: 1) constructed of organically inert materials. 2) weatherproof, 3) battery operated, 4) collecting of VOCs at a breathing zone level, , and 5) quiet operation with micro diaphragm pumps wrapped by the sponge. The pump/battery system was separated from the sampling shelter. Sound levels measured for this system were below permissible sound levels (NJDEP) at a residential site. The sampler has been successfully operated at both ground level in a residential area and on the roof of a one story elementary school.
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