• Title, Summary, Keyword: Particulate matter

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Prediction of Particulate Matter Being Accumulated in a Diesel Particulate Filter (디젤 매연 필터에서 퇴적되는 입자상 물질의 퇴적량 예측)

  • Yu, Jun;Chun, Je-Rok;Hong, Hyun-Jun
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.3
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    • pp.29-34
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    • 2009
  • Diesel particulate filter (DPF) has been developed to optimize engine out emission, especially particulate matter (PM). One of the main important factors for developing the DPF is estimation of soot mass being accumulated inside the DPF. Evaluation of pressure drop over the DPF is a simple way to estimate the accumulated soot mass but its accuracy is known to be limited to certain vehicle operating conditions. The method to compensate drawback is adoption of integrating time history of the engine out PM and burning soot. Present study demonstrates current status of the soot estimation methods including the results from the engine test benches and vehicles.

Influence of Aftertreatment System on the Size Distribution of Diesel Exhaust Particulate Matter (후처리 장치에 의한 디젤엔진 배출가스의 미세 입자 입경분포 변화)

  • 권순박;김민철;이규원;류정호;엄명도;김종춘;정일룩
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.7
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    • pp.113-121
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    • 1999
  • Diesel particulate matter is known to be one of the major harmful emissions produced by diesel engines. Diesel particulates are subject to diesel emission regulations and have lately become the focus in the diesel emission control technology. Thus, the aftertreatment system is adopted at the diesel engine exhaust to reduce the particulate emission. Although this benefit is recognized, it is not clear how the aftertreatment system influences quantitatively the particle size distribution distribution. In this study, the particle size distributions of diesel exhaust were measured using the scanning mobility particle sizer with and without the aftertreatment system. There results showed that the diesel particulate filter and plasm system reduced the number of emitted particles by more than 90% and about 80% respectivley in the particle size range of 20nm∼600nm. On the other hand no significant effect of the diesel oxidation catalyst on the particle number concentration was detected.

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Experimental Study on Estimation of Oxidation Rate of PM inside of Diesel Particulate Filter (DPF내 포집된 입자상 물질의 산화율 산출을 위한 실험적 연구)

  • Shim, Beomjoo;Park, Kyoungsuk;Jo, Kyuhee;Lee, Hyeongjun;Min, Byeongdu
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.2
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    • pp.98-103
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    • 2013
  • Conventional method to estimate mass of particulate matter accumulated in diesel particulate filter is to use pressure difference between upstream and downstream of the filter. Then measured pressure difference should be compared that of clean condition which is no particulate matter accumulated in DPF. During regeneration soot oxidation is also estimated by same method. This methodology, however, has demerit on accuracy because of pressure difference deviation of clean DPFs and pressure difference caused by non-carbon based PM which is different from that of caused by carbon based PM. This study suggests new methodology to estimate accumulated soot oxidation rate through exhaust gas characteristics during regeneration. Results, more high accuracy of soot oxidation was obtained by analysis of relationship between fuel mass and concentration of carbon dioxide and oxygen.

A Study on the Effect on the New Teaching Strategy Facilitating Reflective Thinking in the Learning of the Particulate Nature of Matter (물질의 입자성 학습에서 반성적 사고를 촉진시키는 새로운 입자모델 교수전략의 효과 - 초등학교 예비교사를 대상으로 -)

  • Kim, Do Wook
    • Journal of the Korean Chemical Society
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    • v.44 no.6
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    • pp.600-610
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    • 2000
  • The purpose of this study was to design the new teaching strategy based on the particulate model facilitating the reflective thinking (RE-PM) in the learning of the particulate nature of matter, and to investigate the effect of the new teaching strategy in compare with the traditional teaching strategy (TS-PM) after treating with new teaching strategy on preliminary teachers of elementary school. The problems of traditional teaching strategy are as follows: 1) Most of students didn't think the particulate model connected with practical material. 2) Most of students have a tendency of the rote memory on learning of the traditional particulate model. 3) The ratio of changing the view of continuous matter into the view of particulate nature of matter was very low, after learning the particulate model using of the traditional teaching strategy. The new teaching strategy facilitating the reflective thinking was more effective on the understanding of particulate nature of matter and the driving of motivation than the traditional teaching strategy in the learning of the particulate nature of matter.

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Status of particulate matter pollution in urban railway environments (도시철도 환경의 미세먼지 오염 현황)

  • Kim, Jong Bum;Lee, Seung-Bok;Bae, Gwi-Nam
    • Journal of odor and indoor environment
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    • v.17 no.4
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    • pp.303-314
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    • 2018
  • The urban railway system is a convenient public transportation system, as it carries many people without increasing traffic congestion. However, air quality in urban railway environments is worse than ambient air quality due to the internal location of the source of air pollutants and the isolated space. In this paper, characteristics of particulate matter (PM) pollution in urban railway environments are described from the perspective of diurnal variation, chemical composition and source apportionment of PM. PM concentrations in concourse, platform, passenger cabin, and tunnel are summarized through an analysis of 34 journal articles published in Korea and overseas. This information will be helpful in developing effective policies to reduce PM pollution in urban railway environments.

An Experimental Study on the Smoke Filtration System Using Water Injection and Vacuum Pump driven by Exhaust Gas (물 분사 및 배기가스 구동형 진공펌프를 이용한 매연여과장치에 대한 실험적 연구)

  • Lee, Han-Sung;Kim, Kyong-Hyon;Jung, Suk-Ho;Koh, Dae-Kwon
    • Journal of the Korea Society For Power System Engineering
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    • v.17 no.3
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    • pp.17-22
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    • 2013
  • Diesel particulate filter has been adopted in new vehicle with diesel engine. Since the flow of exhaust gas was clogged as particulate matters were deposited in the filter, it have bad effects on a fuel consumption and power. It was investigated that a particulate filtering system with vacuum pump in the exhaust gas line could be free from clogging in previous research. In this study, the effects of water injection and position of inlet port in filtering system on reducing in particulate matter were investigated. It was noticed that particulate matter were decreased remarkable by water injection and moving the position of inlet port.

Simultaneous Removal Characteristics of Particulate and Elemental Mercury in Convergence Particulate Collector (융합형여과집진장치에서의 먼지입자와 원소수은의 제거 성능 특성)

  • Park, Young Ok;Jeong, Ju Yeong
    • Particle and aerosol research
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    • v.6 no.4
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    • pp.173-183
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    • 2010
  • The high temperature pleated filter bags which were used during this study were made of pleated nonwoven fabric of heat and acid resistant polysulfonate fibers which can withstand the heat up to $300^{\circ}C$ and have a filtration area which is 3 to 5 times larger than the conventional round filter bags. Cartridge module packed with 3 kind of the sulfur impregnated activated-carbon based sorbents were inserted in the inner of the pleated filter bag. This type of pleated filter bag was designed to remove not only the particulate matter but also the gaseous elemental mercury. The electrostatic precipitator part can enhance the particulate removal efficiency and reduce the pressure drop of the pleated filter bag by agglomerated particles to form a more porous dust layer on the surface of the pleated bag which is increased the filter bag cleaning efficiency. In addition, the most of particles are separated from the flue gas stream through the cyclone and the electrostatic precipitator part which were installed at the lower part and main body part of the convergence particulate collector, respectively. Thus reduce particulate loading of the high temperature pleated filter bags were applied in this study to analyze the removal characteristics of particulate matter and gaseous elemental mercury.

Distribution and Transport of Suspended Particulate Matter, Dissolved Oxygen and Major Inorganic Nutrients in the Cheju Strait

  • Suk, Moon-Sik;Hong, Gi-Hoon;Chung, Chang-Soo;Chang, Kyung-Il;Kang, Dong-Jin
    • Journal of the korean society of oceanography
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    • v.31 no.2
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    • pp.55-63
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    • 1996
  • Distribution of suspended particulate matter, dissolved oxygen and major inorganic nutrients along a meridional section ($126^{\circ}$ 33' E) in the Cheju Strait is described along with the hydrographic and current data obtained during April 25-27, 1995. The current measurements was conducted using a vessel-mounted Acoustic Doppler Current Profiler (ADCP). Repeated coverage along an ADCP transect during 25 hours allows to calculate the daily mean along- and cross-strait currents. Measured material concentrations and the mean current speed were used to estimate the flux density (cencentration times current speed) of materials. Two types of depth distibution of flux densities were observed. for nitrate and suspended particulate matter, the depth distribution pattern of materials determines those of flux densities. However, flow patterns determine those of flux densities for dissolved oxygen, phosphate and silicic acid. The total along-strait water volume transport is about 0.3 Sv (1Sv $10^{6}$ $m^{3}/s^{-1}$). The total along-strait material transports are estimated to be 3.1 $${\times} $10^{5}$ $g/s^{-1},$ 2.4 ${\times}$ $10^{6}\;g/s^{-1},$ 7.I ${\times}$ $10^{2}\;mol/s^{-1},$ 3.I ${\times}$ $10\;mol/s^{-1},$ 1.7 ${\times}$ $10^{3}\;mol/s^{-1}$ for suspended particulate matter, dissolved oxygen, nitrate ion, silicic acid and phosphate ion, respectively.

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Distribution of Particulate Organic Matter in the Gampo Upwelling Area of the Southwestern East Sea

  • Yang, Han-Soeb;Oh, Seok-Jin;Lee, Haeng-Pil;Moon, Chang-Ho;Han, Myung-Soo;Kim, Bok-Kee
    • Journal of the korean society of oceanography
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    • v.33 no.4
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    • pp.157-167
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    • 1998
  • The distribution of particulate organic carbon and nitrogen (POC and PON) and chlorophyll a of particulate organic matter was investigated in the southwestern East Sea in August and October 1995. The upwelled 'cold water mass' with temperature less than 14$^{\circ}$C occurred near the Campo coast in August. At most of the onshore stations, concentrations of POC and PON were high in surface water, rapidly decreased with depth down to 30 m and then remained constant. Differences in their concentrations between surface and bottom waters were larger in August than in October. At the offshore stations, POC and PON were higher in surface than in deep waters though the differences in concentration were small. The highest, vertically integrated inventories of POC, PON and phytoplanktonic carbon in the upper mixed waters of the onshore stations occurred in August. The mixed layers at onshore stations showed relatively high percentages of POC, PON and chlorophyll a in total suspended matter, low ratios of POC to chlorophyll a and high inventories of phytoplanktonic carbon, compared with the values at offshore stations. These phenomena were more obvious in August, when cold water mass developed strongly, than in October. These results indicate that primary production plays a significant role for the budget of particulate organic matter in the upwelled cold water mass of the southwestern East Sea.

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