• Title/Summary/Keyword: 입자(particulate)

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A Comparative Study on Ambient Air Quality Standards for Particulate Matters (입자상 오염물질의 대기환경기준에 관한 비교연구)

  • 허정숙;남보현;김동술
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 1999.10a
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    • pp.353-354
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    • 1999
  • 입자상물질에 관한 초기연구는 TSP (Total Suspended Particle)에 집중되었으나, TSP만으로는 인체에 미치는 영향이나 시정악화 같은 현상을 정확하게 설명한 수 없었다. 보건학적 관점에서, PM10과 사망률사이에 강한 상관관계가 있는 것으로 조사된 바 있으며 (Pope et al, 1995), 특히 PM10 중에서 미세입자 (PM2.5미만)는 인체에 미치는 영향이 더욱 큰 것으로 알려지고 있다 (Joel et al., 1996). 이에 따라 입자상 물질의 규제 관리는 미세입자 측면에서 강화될 필요가 있다.(중략)

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Measurements of Particulate Matters for the HSDI Diesel Engine with DOC using the ELPI (ELPI를 이용한 산화촉매 장착 고속 직접분사식 디젤엔진의 입자상물질 계측)

  • Choi, Byung-Chul;Jang, Se-Hyun
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.2245-2250
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    • 2003
  • Particulate matters(PM) have bad effect on the health. We carried out measurements of diesel PM under $10{\mu}m$ diameter from a HSDI diesel engine with a diesel oxidation catalyst(DOC) by using the ELPI. This paper compares the two results of the smoke level and the PM level of masses and numbers. We also investigated the effect of the DOC. Under high speed and load, HSDI diesel engine exhausts much masses of particulate matters over 100nm diameter, and a number of PM from 7 to 100nm diameters at the same condition. DOC could reduce the total mass of the PM. However, the DOC could increase the number of ultra fine PM. Before light-off of the soot, the DOC absorb the PM and the DOC oxidize the PM after light-off temperature. The fine PM could be made during the oxidation. Therefore, the advanced DOC is needed to reduce the number of the fine PM.

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Adhesion of Soil to Polyester Fabric According to Polarity of Oily Soil in Oily/Particulate Mixed Soil System (지용성/고형오구의 혼합오염 계에서 지용성오구의 극성에 따른 Polyester직물에의 오구부착)

  • Kang, In-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.7
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    • pp.1175-1183
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    • 2010
  • This study investigates the effect of polarity of oily soil on adhesion of oily and particulate soil to PET fabric in oily/particulate mixed soil systems. The potential energy of interaction between two particles was examined as a fundamental environment of adhesion of soil to fabrics. The ${\zeta}$-potential of ${\alpha}-Fe_2O_3$ particles was measured by a microelectrophoresis method, and the potential energy of interaction between two particles was calculated by using the Verwey-Overbeek theory. The ${\zeta}$-potential of particle and the potential energy of interaction between two particles was slightly influenced by the polarity and type of oily soil, but increased with the increased anionic surfactant concentration and amount of oily soil. The adhesion of oily soil to fabric increased with the additional amount of polarity of oily soil and decreased surfactant concentration that was relatively high at a temperature of $60^{\circ}C$ surfactants solution. The adhesion of ${\alpha}-Fe_2O_3$ particle to PET fabric decreased with an increased amount and polarity of oily soil and increased surfactant concentration Although some similarity exists, the general trend of the adhesion to fabric by particulate soil differ from oily soil.

Effects of Particle Measuring Conditions on Diesel Nanoparticles Distribution (입자측정조건이 디젤 나노입자의 입경분포에 미치는 영향)

  • Lee, Jin-Wook;Kim, Hong-Suk;Jeong, Young-Il
    • Journal of Korean Society for Atmospheric Environment
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    • v.22 no.5
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    • pp.653-660
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    • 2006
  • Due to the stronger exhaust emission regulations and the introduction of advanced technology in Diesel engine, the specific Diesel particulate matters have decreased by about one order of magnitude since the 1980's. In recent years, particle number emissions rather than particulate mass emissions have become the subject of controversial discussions. Recent results from health studies imply that it is possible that particulate mass does not properly correlated with the variety of health effects attributed to Diesel exhaust. Concern is instead now focusing on nano-sized particles. This study has been performed for the better understanding about the Diesel nano-particle measurement and size distribution characteristics in the exhaust system of a turbo charged Diesel engine. A scanning mobility particle sizer(SMPS) system was applied to measure the particle number and size concentration of Diesel exhaust particles. As the experimental results, the number concentrations in the particle size (Dp<200 nm) were very sensitive to dilution conditions. Specially the changes in nano-particle number concentrations(Dp<50 nm) increased along the downstream of exhaust flow. Also we found the dilution conditions were influencing the condensation of SOF and $H_2O$ during dilution and cooling of hot exhaust.

A Study on the Shapes of Aerosol Particles at a Bus Stop in the Eastern Part of Seoul (도심 내 버스정류장 부근의 에어로졸 입자 크기 및 형상 관찰)

  • Jeong, Sang Bin;Heo, Ki Joon;Sin, Chang Hoon;Zhao, YuanQing;Lee, Byung Uk
    • Particle and aerosol research
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    • v.12 no.4
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    • pp.109-114
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    • 2016
  • People in metropolitan cities can be exposed to particulate air pollutants at public transportation systems such as bus stops. In this study, we sampled aerosol particles with an impactor at a bus stop. We analyzed the shapes of these particles with an optical microscope. It was estimated that fibers, silicons, byproducts of combustion, and pollens existed in the air environments at the bus stop with analysis of shapes of sampled particles.

Nondestructive Determination of Reinforcement Volume Fractions in Particulate Composites : Eddy Current Method (비파괴적 방법에 의한 입자 강화 복합재료의 부피분율 평가: 와전류법)

  • Jeong, Hyun-Jo
    • Journal of the Korean Society for Nondestructive Testing
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    • v.18 no.2
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    • pp.112-120
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    • 1998
  • A nondestructive evaluation technique was developed for the quantitative determination of the reinforcement volume fractions in particulate reinforced metal matrix composites. The proposed technique employed a composite micromechanics which accounts for the microstructure of the composite medium together with the measurement of anisotropic electrical conductivity. When the measured conductivity was coupled with the theoretically predicted conductivity, the unknown reinforcement volume fraction was calculated. An analytical model based on the Mori-Tanaka method was described which relates the NDE signatures to the composite microstructure. The volume fractions were calculated using eddy current measurements made on a wide range of silicon carbide particulate ($SiC_p$) reinforced aluminum (Al) matrix composites. The calculated $SiC_p$ volume fractions were in good agreement with the measured volume fractions in the range of 0-30%. The technique was also found to be effective in estimating the total volume percentage of reinforcement and intermetallic compound formed during the processing stage.

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High Temperature Deformation Behaviour of Particulate Reinforced Aluminium Composites (입자분산강화 알루미늄 복합재료의 고온거동에 관한 연구)

  • Gwon, Hyeok-Cheon;Yun, Ui-Park
    • Korean Journal of Materials Research
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    • v.5 no.7
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    • pp.765-774
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    • 1995
  • The hot deformation behaviour of particulate reinforced aluminium 6061 Al composite were investigated by hot compression tests in the temperature range from 623K to 823K with strain rate of 10$^{-3}$ ~5.0 S$^{-1}$ . The effect of reinforced particulate volume fraction, mean diameter on the high temperature flow stress has also been studied. Experimental results showed that the increase in the volume fraction of reinforcement contributed to the rising of yield stress, but the stress above the yield point appeared to be steady state at all volume fractions. The apparent activation energy for deformation was 290KJ/mo1 for unreinforced 6061 Al, 327KJ/mo1 for 6061 Al-20vo1.% SiC composite and 531KJ/mo1 for 6061 Al-20vo1.%A1$_2$O$_3$composite. It appeared that $Al_2$O$_3$reinforced composites was more difficult to hot deform.

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Experimental Evaluation of Particulate-matter Filtration Performance of a Bottom Ash-Silica Sand Mixture (석탄 저회-규사 필터의 입자상물질 여과 성능 실험적 평가)

  • Lee, Dong-Hyun;Lee, Hong-Kyoung;Lee, Yun-Jae;An, Jaehun
    • Journal of the Korean Geotechnical Society
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    • v.38 no.6
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    • pp.41-47
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    • 2022
  • Permeable pavement technology allows the penetration of rainfall into the roadbed, thereby reducing surface runoff and enhancing water quality. The water quality can be improved by adding a filter layer to the permeable pavement. This study analyzes the permeability performance and particulate-matter removal efficiency of a bottom ash-silica sand filter. The performances of five filters with bottom ash and silica sand as the basic materials were evaluated on particulate matter sized 60 ㎛ or smaller. The pure silica sand sample and pure bottom ash sample delivered an average removal efficiency of around 70%. The removal efficiency of the mixed sample was approximately 90%, exceeding the recommended reduction rate (80%) at non-point pollution reduction facilities. In future work, the filter performance should be further verified on permeable pavement.

Annual Change and C:N:P ratio in Particulate Organic Matter in Chinhae Bay, Korea (한국진해만 입자유기물 함량과 C:N:P 비의 연변화)

  • LEE, PIL-YONG;KANG, CHANG-KEUN;PARK, JONG-SOO;PARK, JOO-SUCK
    • 한국해양학회지
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    • v.29 no.2
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    • pp.107-118
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    • 1994
  • An investigation of the annual change and C:N:P ratio in particulate organic matter (POM) in Chinhae Bay, a semi-enclosed bay of the southern coast of Korean Peninsula, was carried out for a period of 12 months between January and December, 1993. The concentrations of POM have a broad range: 198∼4,416 ugC/l, 24∼792 ugN/l and 4.5∼69.0 ugP/l, Marked seasonal changes of POM, particularly particulate organic carbon (POC) and nitrogen (PON), were observed in the surface water. Generally, the concentration of POM peaks in summer. The C:N:P composition ratio of particulate organic matter, which is high in summer, also shows a seasonal change. The C:N assimilation ratio is constant at 6.53, which is consistent with the Redfield ratio. The significant linear relationship between POM and chlorophyll-a in the surface water during the survey period (except for January and February) and the C:N ratio suggest that the concentration of POM is controlled by phytoplankton biomass. POM peaks in summer, a period characterized by high freshwater input and the strong stratification, as a result of the intense proliferation of phytoplankton by a large amount of nutrient loading from the tributaries. On the other hand, the high C:P and N:P ratios in summer indicate that P is limited for phytoplankton growth owing to N-enrichment from a high input of freshwater with a high dissolved inorganic N:P ratio.

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Electron Microscopic Study on the Mast Cells of the Vertebrates(Mammals) Stomach (척추동물(脊椎動物)(포유류(哺乳類))위(胃)의 비만세포(肥滿細胞)에 관한 전자현미경적 연구)

  • Kang Ho-Suck;Kim Chang-Whan
    • Applied Microscopy
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    • v.11 no.1
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    • pp.39-50
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    • 1981
  • An electron microscopical observation was carried out to compare the general shape of the mast cells and structures of granules inside the cells in the stomach of 5 species in 3 orders of Mammals. In convenience, the granules in the cytoplasm were abbreviated as follows: 1) Homogeneous granule, GR1 2) Particulate granule, GR2 a. Dark dense particulate granule, GR2-1 b. Less dense particulate granule, GR2-2 3) Reticular granule, GR5 a. Dark dense reticular granule, GR5-1 b. Light dense reticular granule, GR5-2 In Mammalia including goat, dog, cat, and hamster, most of cytoplasmic organelle were Golgi apparatus and mitochondria, and most of the cytoplasmic granules were highly densed GR1and GR2. However GR5-1 and GR5-2 appeared in guinea pig while one side sunken or crescent-like types occured in both dog and guinea pig. All mast cells were oval or spindle with cytoplasmic processes around the cell. There was also found vacuoles and vesicles in these cells. These results demonstrated that there was a morphological difference between species of vertebrate in the mast cells and their cytoplasmic granules. It was also suggested that a variety of structures of granules were closely related with the composition (histamine, heparin, serotonin, hyaluronic acid etc.) and mature of the granules.

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