• Title/Summary/Keyword: Model Diesel Particles

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Generation of Model Diesel Particles by Spark Discharge and Hydrocarbon Condensation

  • Kim, Hak-Joon;Kim, Jin-Ho;Choi, Young-Joo;Oh, Hyen-Chul;Chu, Jung-Bum;Kim, Sang-Soo
    • Journal of Mechanical Science and Technology
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    • v.20 no.11
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    • pp.1972-1979
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    • 2006
  • This study was conducted in order to generate model particles which were similar to particles in diesel emission. Spark discharge was used for carbon agglomerates and hydrocarbon condensation for particles that consist of carbon agglomerates and hydrocarbon. The size of the carbon agglomerates, whose mean size were 30 and 70 nm, ranged between 15 and 200 nm, and the total number concentration of the particles ranged from 3 to $5{\times}10^7#/cm^3$ as the controllable variables in spark discharge generator changed. The result of the hydrocarbon condensation experiment showed that the final sizes of the particles enlarged by condensation did not depend on the initial sizes, but the maximum condensational growth of carbon agglomerates by dodecane ($C_{12}H_{26}$) condensation was 112 times the initial size of 40 nm, while the size of the agglomerates by benzene ($C_6H_6$) was 3.25 times its initial size.

Exposures of Ultrafine Particles for Passengers of Elephant Vehicle in the Seoul Grand Park (서울대공원 코끼리 열차 특성에 따른 탑승자의 초극미세입자(Ultrafine Particles) 노출)

  • Joo, Song-Yi;Hwang, Ji-Hee;Ham, Seung-Hon;Lee, Ki-Young
    • Journal of Environmental Health Sciences
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    • v.38 no.5
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    • pp.393-397
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    • 2012
  • Objectives: The objectives of this study were to measure passengers' exposure to ultrafine particles (UFP) and to determine effects of fuel, operating condition and position of seat. Method: UFP exposures in front and back seats of the Elephant vehicle in Seoul Grand Park were simultaneously measured by a condensation particle counter (P-Trak model 8525, TSI). The measurements were conducted 7 times with diesel-powered vehicle and 3 times with electricity vehicle in one day. The vehicle stopped at 3 locations along with 2.2 km of driving route. Results: UFP concentration in diesel-powered vehicle was significantly higher than electricity vehicle. At front seat of diesel-powered vehicle, average UFP exposure during stopping was significantly higher than during moving. When diesel-powered vehicle moved, UFP exposure in back seat was significantly higher than in front seat. Conclusions: Passengers in the diesel-powered Elephant vehicle could be exposed to high level of UFP. The UFP exposure was associated with operation condition and position of seat.

Antiasthmatic Effects on Scutellaria baicalensis Georgi Extracts Against Airway Inflammation and Hyperresponsiveness Induced by Diesel Exhaust Particles with Ovalbumin Sensitization (Ovalbumin과 디젤배기가스 입자로 유도된 기도염증과 기도 과민성에 대한 황금 추출물의 항천식 효과)

  • Lim, Heung-Bin;Kim, Seung-Hyung
    • Korean Journal of Medicinal Crop Science
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    • v.20 no.2
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    • pp.129-135
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    • 2012
  • The feature of asthma are airway inflammation (AI), reversible airway obstruction, and an increased sensitivity to bronchoconstricting agents, elevated airway hyperresponsiveness (AHR), excess production of Th2 cytokines, and eosinophil accumulation in the lungs. This study was performed to investigate if oral administration of $Scutellaria$ $baicalensis$ Georgi water extracts (SBG) have the antiasthmatic potential for the treatment of asthma. Asthmatic HI and AHR were induced by systemic sensitization to ovalbumin (OVA) with intratracheal instillation with 0.1 mg/mL of diesel exhaust particles (DEP) suspension once a week for 10 weeks in BALB/c mice. SBG was orally administered with the concentraion of 200 mg/kg 5 days a week for 10 weeks. Long-term SBG treatment suppressed the eosinophil infiltration into airways from blood, the asthmatic AI and AHR by attenuating the production of cytokine IL-4, IL-5 and IL-13, histamine and OVA-specific IgE. Our data suggest that SBG has inhibitory effects on AI and AHR in a mouse model of asthma, may act as a potential Th2 cytokine antagonist, and may have a therapeutic effect on allergic asthma.

Chemopreventive Effect of Vegetable or Fruit Extract Against Total Diesel Exhaust Particle Extract in NIH/3T3 Cells Using Alkaline Single Cell Gel Electrophoresis (총 디젤분진의 DNA 손상작용과 야채 및 과일추출물의 보호효과)

  • Heo Chan;Kim Nam-Yee;Heo Moon-Young
    • Environmental Analysis Health and Toxicology
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    • v.21 no.2 s.53
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    • pp.127-138
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    • 2006
  • In urban areas, diesel exhaust particles (DEP) are probably a major component of particulate matters, especially in Korea where drive many diesel vehicles. The aim of this study was to investigate genotoxic effects of DEP using single ceil gel electrophoresis. In order to evaluate the mechanisms of DEP genotoxicity, the rat microsome mediated and DNA repair enzyme treated comet assays together with conventional comet assay were performed. Total diesel particles (DEPT) was collected without site fractionation from diesel engine bus and dichloromethane extract was obtained. The organic extract of DEPT revealed DNA damage itself in NIH/3T3 cells. The level of DNA breaks plus oxidative DNA lesions and microsome mediated DNA damage was assessed by modified single cell gel eletrophoresis. DEPT was able to induce oxidative DNA damage as well as microsome mediated DNA damage. Vitamin C as an model antioxidant reduced DNA damage in endonuclase III treated comet assay. One of flavonoid, galangin as a CYP1A1 inhibitor. reduced DNA damage in the presence of S-9 mixture. $DEP_T$ is the sources of oxidative stress, but antioxidants can significantly reduce oxidative DNA dmage. And $DEP_T$ may contain indirect mutagens which can be inhibited by CYP1A1 inhibitors. The ethanol extracts of the mixed vegetables (BV) or the mixed fruits (BF) were evaluated for their in vitro antigenotoxic effects. BV and BF showed potent Inhibitory effects against DEPT induced DNA damage with oxidative DNA lesions and in the prescence of S-9 mixture. These results indicate that BV and BF could prevent cellular DNA damage by inhibiting oxidative stress and suppressing cytochrome P4501A1 in cell culture.

A Study on the Structure of Axial-Symmetric Two-Phase Spray and Flame (축대칭 이류체 분무화염의 구조에 관한 연구)

  • Jung, Bo-Yoon;Ko, Dae-Kwon;Ahn, Soo-Kil
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.24 no.1
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    • pp.36-43
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    • 1988
  • Boilers and diesel engines have many problems because their exhaust particles, i.e., soot have lots of bad influence on environment. And it's spray and flame have fundamentally axial symmetric shape. To investigate the relationship between fuel concentration distribution of spray and soot concentration distribution as well as temperature distribution of flame, we made a axial symmetric two phase spray-flame and analyzed the structure of is. The measuring method is the principle of the light extinction method for the spray-flame and onion peeling model is applied to analyze the radial distribution of fuel and soot concentration. The temperature of flame is measured by ø 0.4mm Pt-Pt.RH 3% thermocouple. The oils for the experiments are diesel oil and 10% water emulsified diesel oil. It was found that the soot concentration becomes higher as it comes near to the center of flame, and the fuel concentration does, too. And the soot concentration level of diesel oil is generally higher than that of the 10% water emulsified fuel. The maximum flame temperature of diesel oil is 1,17$0^{\circ}C$, however, 10% water emulsified diesel oil is 1,27$0^{\circ}C$.

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Antiasthmatic effects on Pinellia ternate Breitenbach(PTB) water extracts against airway inflammation and hyperresponsiveness induced by diesel exhaust particles with ovalbumin sensitization in BALB/c mice (생쥐에서 ovalbumin과 디젤배기가스 입자로 유도된 기도염증과 기도 과민성에 대한 반하 물 추출물의 항천식 효과)

  • Kim, Seung Hyung;Lim, Heung Bin
    • The Korea Journal of Herbology
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    • v.28 no.1
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    • pp.65-71
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    • 2013
  • Objectives : Asthma is a chronic, complex respiratory disease, caused by airway obstruction, airway eosinophilic inflammation(AEI), and airway hyperresponsiveness(AHR). This study was conducted to determine whether oral administration of crude water extracts of Pinellia ternate Breitenbach(PTB) has an antiasthmatic potential in the treatment of asthma in mice. Methods : Asthmatic AEI and AHR were induced by systemic sensitization to ovalbumin(OVA) by intratracheal instillation with 0.1 mg/mL suspension of diesel exhaust particles(DEP) once a week for 10 weeks in BALB/c mice. Crude PTB water extracts(50 mg/kg and 200 mg/kg) were orally administered 5 times a week for 10 weeks. Cyclosporin(10 mg/kg) was administrered the same manner as a positive control. Results : Long-term treatment with crude PTB water extracts suppressed the infiltration of inflammatory cells, including eosinophils, into airways from blood. It also reduced asthmatic AEI and AHR by attenuating the increase in the levels of cytokines such as interleukin(IL)-4, IL-5 and IL-13 in bronchoalveolar lavage fluid(BALF), as well as the levels of histamine and OVA-specific IgE in blood. However, the effect of crude PTB water extracts(200 mg/kg) was not likely to be stronger than that of cyclosporin(10 mg/kg). Conclusion : These results suggest that crude PTB water extracts have inhibitory effects on AEI and AHR in a mouse model of asthma and may act as a potential Th2 cytokine antagonist, and have a therapeutic effect on allergic asthma.

Modeling of thermal fluidized desorption for diesel-oil contaminated soils (Diesel-oil에 오염된 토양의 유동상 열탈착 모델링)

  • 이상화;김병욱;이상득;박달근;이중기
    • Journal of Korea Soil Environment Society
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    • v.4 no.2
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    • pp.137-147
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    • 1999
  • Fluidized-bed thermal desorber coupled with a heat pipe was investigated for the remediation of soil contaminated with diesel oils. Thermal gravimetric analysis by Cahn-balance indicated that the desorption of diesel oils from the soil particles was mainly governed by the internal diffusion at low concentration of less than 0.5 wt. % of oils in the soil particles. In fluidized-bed experiments. increase of fluidizing gas velocity reduced the residual oils of the contaminated soils, the increase of soil feed rate decreased efficiency of fluidized-bed desorber. A mathematical model was developed by incorporating Fickian diffusion kinetics into the Kunii-Levenspiel model Simulation results showed reasonable agreement for the performance of fluidized-bed thermal desorber.

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A Review on the Characteristics of Air Pollutants Emitted from Passenger Cars in Korea

  • Jung, Sungwoon;Kim, Jeongsoo
    • Journal of ILASS-Korea
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    • v.21 no.4
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    • pp.223-236
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    • 2016
  • On-road source emissions are major air pollutants and have been associated with serious health effects in Seoul metropolis. Thus, it is of fundamental importance to have an accurate assessment of vehicle emissions in order to implement an effective air quality management policy. As a result, there is a need to overview vehicle emission characteristics of air pollutants. This article discusses vehicle exhaust sampling and chemical analysis, emission characteristics of air pollutants, and emission regulations from passenger cars. The vehicle exhaust sampling and chemical analysis methods were described in particulate matter and gaseous compounds. In this article, chassis dynamometer, measurement instrumentation for nano-particulate matter and carbon compounds analysis device were described. For the gasoline and diesel vehicles, the effective parameters of emissions were average vehicle speed, vehicle mileage and model year. The particle number emissions for diesel nano-particles were sensitive to the sampling conditions. Also, the particle number emissions with a diesel particle filter (DPF) largely reduced rather than those without it. This article also describes different emission characteristics of air pollutants according to biodiesel or bioethanol mixing ratio. The Korean emission standards for passenger cars were compared with those of the US and EU. Finally, the objective is to give an overview of relevant background information on emission characteristics of air pollutants from passenger cars in Korea.

Chemical Composition of PM2.5 and PM10 and Associated Polycyclic Aromatic Hydrocarbons at a Roadside and an Urban Background Area in Saitama, Japan

  • Naser, TarekMohamed;Yoshimura, Yuji;Sekiguchi, Kazuhiko;Wang, Qingyue;Sakamoto, Kazuhiko
    • Asian Journal of Atmospheric Environment
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    • v.2 no.2
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    • pp.90-101
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    • 2008
  • The chemical compositions of $PM_{2.5}$ and $PM_{10}$ and associated high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) were investigated during winter and summer at a roadside and an urban background site in Saitama, Japan. The average concentrations of $PM_{2.5}$ exceeded the United States Environmental Protection Agency standards during both periods. Carbonaceous components were abundant in both the observed and calculated (by means of a mass closure model) chemical composition of $PM_{2.5}$. Traffic-related pollutants (elemental carbon and high-molecular-weight PAHs) were strongly associated with $PM_{2.5}$ rather than with larger particles. The mass concentrations of $PM_{2.5}$, as well as those of EC and PAHs associated with the particles, at the two sites were strongly correlated. Comparison of our data with source profile ratios indicates that diesel-powered vehicles were probably the main source of the measured PAHs. The PAHs concentrations were affected by meteorological conditions during our study. Our results highlight the need for the establishment of standards for $PM_{2.5}$ in Japan.

A Basic Study of the Behavior Characteristics of Diesel Spray and Natural-gas Jet (디젤 분무와 천연 가스 분류의 거동 특성에 관한 기초 연구)

  • Yeom, J.K.;Kim, M.C.
    • Journal of Power System Engineering
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    • v.13 no.6
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    • pp.13-21
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    • 2009
  • This basic study is required to examine spray or jet behavior depending on fuel phase. In this study, analyses of diesel fuel(n-Tridecane, $C_{13}H_{28}$) spray and natural gas fuel(Methane, $CH_4$) jet under high temperature and pressure are performed by a general-purpose program, ANSYS CFX release 11.0, and the results of these are compared with experimental results of diesel fuel spray using the exciplex fluorescence method. The simulation results of diesel spray is analyzed by using the combination of Large-Eddy Simulation(LES) and Lagrangian Particle Tracking(LPT) and of a natural gas jet is analyzed by using Multi-Component Model(MCM). There are two study variables considered, that is, ambient pressure and injection pressure. In a macroscopic analysis, the higher ambient pressure is, the shorter spray or jet tip penetration is at each time after start of injection. And the higher injection pressure is, the longer spray or jet tip penetration is at each time after start of injection. When liquid fuel is injected, droplets of the fuel need some time to evaporate. However, when natural gas fuel is injected, the fuel does not need time to evaporate. Gas fuel consists of minute particles. Therefore, the gas fuel is mixed with the ambient gas more quickly at the initial time of injection than the liquid fuel is done. The experimental results also validate the usefulness of this analysis.

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