• Title, Summary, Keyword: Generated aerosols

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An Experimental Study on the Proper Supply Method of Metal Cutting Coolant (절삭유 공급 방식의 최적화를 위한 실험적 연구)

  • 강재훈;송준엽;최종호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.977-980
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    • 2004
  • Metalworking fluids (MWFs) are fluids used during machining and grinding to prolong the life of the tool, carry away debris, and protect the surfaces of work pieces. These fluids reduce friction between the cutting tool and the work surface, reduce wear and galling, protect surface characteristics, reduce surface adhesion or welding and carry away generated heat. Workers can be exposed to MWFs by inhaling aerosols (mists) and by skin contact with the fluid. Skin contact occurs by dipping the hands into the fluid, splashes, or handling workpieces coated with the fluids. The amount of mist generated (and the resulting level of exposure) depends on many factors. To reduce the environmental pollution wastes and the potential health risks associated with occupational exposures to MWFs, it is required to establish optimum MWFs supply method and condition with minimum quantity in all over the mechanical machining field including high-speed type heavy cutting process.

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Reliability Evaluation Technology of Metal Working Fluids Supply Method (절삭유 공급 방식의 신뢰성 평가 기술)

  • 강재훈;송준엽;이승우;박화영;박종권
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • pp.206-208
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    • 2002
  • Metalworking fluids (MWFs) are fluids used during machining and grinding to prolong the life of the tool , carry away debris, and protect the surfaces of work pieces. These fluids reduce friction between the cutting tool and the work surface, reduce wear and galling, Protect surface characteristics, reduce surface adhesion or welding and carry away generated heat. Workers can be exposed to MWFs by inhaling aerosols (mists) and by skin contact with the fluid. Skin contact occurs by dipping the hands into the fluid, splashes, or handling workpieces coated with the fluids. The amount of mist generated (and the result ins level of exposure) depends on many factors. To reduce the potential health risks associated with occupational exposures to MWFs, it is required to establish optimum MWFs supply method and condition with minimum Quantity in all over the mechanical machining field including high speed type heavy cult ing process.

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An Analysis of Generation and Growth of Multicomponent Particles in the Modified Chemical Vapor Deposition (수정된 화학증착공정에서 다종 성분 입자 생성 및 성장 해석)

  • Lee, Bang Weon;Park, Kyong Soon;Choi, Mansoo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.5
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    • pp.670-677
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    • 1999
  • An analysis of generation and growth of multicomponent particles has been carried out to predict the size and composition distributions of particles generated in the Modified Chemical Vapor Deposition(MCVD) process. In MCVD process. scale-up of sintering and micro-control of refractive index may need the Information about the size and composition distributions of $SiO_2-GeO_2$ particles that are generated and deposited. The present work solved coupled steady equations (axi-symmetric two dimensions) for mass conservation, momentum balance. energy and species(such as $SiCl_4$, $GeCl_4$, $O_2$, $Cl_2$) conservations describing fluid flow. heat and mass transfer in a tube. Sectional method has been applied to obtain multi-modal distributions of multicomponent aerosols which vary in both radial and axial directions. Chemical reactions of $SiCl_4$ and $GeCl_4$ were included and the effects of variable properties have also been considered.

A Study on the Establishment of Proper Metalworking Fluids Supply Method to Reduce the amount Used (절삭유 사용량의 억제를 위한 적절한 공급 방식의 설정을 위한 연구)

  • 강재훈;송준엽;송철원;최종호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.1803-1806
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    • 2003
  • Metalworking fluids (MWFs) are fluids used during machining and grinding to prolong the lift of the tool, carry away debris, and protect the surfaces of work pieces. These fluids reduce friction between the cutting tool and the work surface. reduce wear and galling, protect surface characteristics, reduce surface adhesion or welding and carry away generated heat. Workers can be exposed to MWFs by inhaling aerosols (mists) and by skin contact with the fluid. Skin contact occurs by dipping the hands into the fluid, splashes, or handling workpieces coated with the fluids. The amount of mist generated (and the resulting level of exposure) depends on many factors. To reduce the environmental pollution wastes and the potential health risks associated with occupational exposures to MWFs, it is required to establish optimum MWFs supply method and condition with minimum quantity in all over the mechanical machining field including high-speed type heavy cutting process.

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Signal compensation by the light scattering of sample aerosols in ICP-AES (ICP-AES에서 에어로졸의 광산란에 의한 신호의 보정)

  • Yeon, Pyung-Hum;Pak, Yong-Nam
    • Analytical Science and Technology
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    • v.25 no.4
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    • pp.223-229
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    • 2012
  • Analytical signal from ICP was compensated by the light scattering of sample aerosols. Reference scattering signal was generated by a He-Ne or diode laser, monitored for the amount of aerosol producing and used for the compensation of analytical signals. The result showed that significant improvement in precision could be achieved for the short-term signal (within 1 minute) from 3.4% to 0.9% RSD in signal and 14.9% to 4.2% for the long-term (10 minutes) for Be, Pb and Co. This method is very useful not only for the pulse type but for continuous type signals especially when a nebulizer is unstable. To improve long-term precision, higher stability is required in the scattering cell and detector as well as the reduction of noise from the line between a nebulizer and plasma.

Characterization of Summertime Aerosol Particles Collected at Subway Stations in Seoul, Korea Using Low-Z Particle Electron Probe X-ray Microanalysis

  • Kim, Bo-Wha;Jung, Hae-Jin;Song, Young-Chul;Lee, Mi-Jung;Kim, Hye-Kyeong;Kim, Jo-Chun;Sohn, Jong-Ryeul;Ro, Chul-Un
    • Asian Journal of Atmospheric Environment
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    • v.4 no.2
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    • pp.97-105
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    • 2010
  • A quantitative single particle analytical technique, denoted low-Z particle electron probe X-ray microanalysis (low-Z particle EPMA), was applied to characterize particulate matters collected at two underground subway stations, Jegidong and Yangje stations, in Seoul, Korea. To clearly identify the source of the indoor aerosols in the subway stations, four sets of samples were collected at four different locations within the subway stations: in the tunnel; at the platform; near the ticket office; nearby outdoors. Aerosol samples collected on stages 2 and 3 ($D_p$: $10-2.5\;{\mu}m$ and $2.5-1.0\;{\mu}m$, respectively) in a 3-stage Dekati $PM_{10}$ impactor were investigated. Samples were collected during summertime in 2009. The major chemical species observed in the subway particle samples were Fe-containing, carbonaceous, and soil-derived particles, and secondary aerosols such as nitrates and sulfates. Among them, Fe-containing particles were the most popular. The tunnel samples contained 85-88% of Fe-containing particles, with the abundance of Fe-containing particles decreasing as the distances of sampling locations from the tunnel increased. The Fe-containing subway particles were generated mainly from mechanical wear and friction processes at rail-wheel-brake interfaces. Carbonaceous, soil-derived, and secondary nitrate and/or sulfate particles observed in the underground subway particles likely flowed in from the outdoor environment by human activities and the air-exchange between the subway system and the outdoors. In addition, since the platform screen doors (PSDs) limit air-mixing between the tunnel and the platform, samples collected at the platform at the Yangjae station (with PSDs) showed a marked decrease in the relative abundances of Fe-containing particles compared to the Jegidong station (without PSDs).

Development of Aerosol-LIBS (Laser Induced Breakdown Spectroscopy) for Real-time Monitoring of Process-induced Particles (공정 중 발생 오염입자 실시간 모니터링을 위한 에어로졸-레이저 유도 플라즈마 분광분석 시스템 개발)

  • Kim, Gibaek;Kim, Kyoungtae;Maeng, Hyunok;Lee, Hae Bum;Park, Kihong
    • Particle and aerosol research
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    • v.12 no.3
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    • pp.57-63
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    • 2016
  • The laser-induced breakdown spectroscopy (LIBS) has been used for rapid detection of elemental compositions of various materials in multi-media (solid, liquid, gas, and aerosols). In this study, the aerosol-LIBS has been developed for real-time monitoring of process-induced particles produced during the semiconductor manufacturing. The developed aerosol-LIBS mainly consists of laser, optics, spectrometer, and aerosol chamber. A new aerosol chamber was constructed for the aerosol-LIBS to be applied for various semiconductor manufacturing process, including exhaust tubes, and low pressure and high temperature chamber. The aerosol-LIBS was evaluated by using laboratory generated aerosols for detection of various elements. As a result, P, Fe, Mg, Cu, Co, Ni, Ca, Na, and K emission lines were successfully detected by the aerosol-LIBS. Further evaluation of the aerosol-LIBS is being conducted.

A Study on the Deposition of Permalloy Nanostructured Thin Film Utilizing Supersonic Deposition of Nanoparticles Formed by Laser Ablation of Microparticles (마이크로입자의 레이저 Ablation으로 형성된 나노입자의 수펴소닉 적층법을 이용한 퍼멀로이 나노구조박막 적층에 관한 연구)

  • Yun, Eui-Jung;Jung, Myunghee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.5
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    • pp.478-483
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    • 2005
  • In this paper, we synthesized 10 to 20 nm diameter NiFe nanoparticles and nanoparticle films utilizing supersonic jet deposition of nanoparticle aerosols generated by laser ablation of $30\;to\;45{\mu}m$ diameter permalloy $(Ni_{81}Fe_{19} \;at\;{\%})$ microparticles. The component and composition of the nanoparticles were characterized by an energy dispersive X-ray spectroscopy. The morphology of the nanoparticles and nanoparticle films was analyzed by a high-resolution transmission electron microscopy and a scanning electron microscopy, respectively. The experimental results showed that the nanoparticles and nanoparticle films have remarkable properties with an excellent preservation of the composition of feedstock permalloy microparticles. The purpose of the present work is to present details on the composition and nanostructural characterizations for NiFe nanoparticles and nanoparticle films prepared by laser ablation of microparticles (LAM).

A Study on the Collection Characteristics of Submicron Particles in an Electrostatic Precipitator - I. Electrical Characteristics (전기 집진기에서의 Submicron 입자의 집진 특성에 관한 연구-I. 전기적 특성)

  • 김용진;황태근;유주식
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.7
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    • pp.572-578
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    • 2001
  • This study conducts a laboratory measurement on a cylindrical electrostatic precipitator(ESP) with a 30mm-diameter cylinder. Several kinds of test aerosols are generated with an atomizer and a diffusion dryer. The effects of applied voltage, flow state, gas velocity, and gas temperature on the electrical characteristics of the precipitator and onset of corona are experimentally investigated. The corona onset voltage is decreased, as diameter of discharge electrode wire becomes small or temperature of the precipitator increases. As the fluid velocity or particle load in the precipitator increases, the corona current is decreased.

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Removal Performance of Sticky Paint Aerosol Control System Generated from Small Scale Car Paint Overspray Booth (소형 자동차 페인트 도장부스에서 발생하는 점착성 paint aerosol 처리장치에서 제거성능)

  • Lee, Jae-Rang;Hasolli, Naim;Jeon, Seong-Min;Lee, Kang-San;Sohn, Jong-Ryeul;Park, Young-Ok
    • Journal of Korean Society for Atmospheric Environment
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    • v.31 no.1
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    • pp.54-62
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    • 2015
  • Small scale paint overspray booths are being operated nationwidely, for repair of passenger car body parts. paint aerosols are emitted from the paint overspray booth in operations. In paint overspray booth operations without ventilation system and air pollutants collection unit, it may land on nearby equipment. In this study a removal of sticky paint aerosol for application of the small-scale overspray paint booth. it's cause the surface of filter bag from generated sticky paint aerosol. To remove adhesion of paint aerosol the agglomerating agents are injected and mixed with sticky paint aerosols prior to reach the filter bag. The paint spray rate was set as $10{\pm}5g/min$ from air-atomized spray guns in the spray booth, injection rate of agglomerating was $10{\pm}5g/min$ in the mixing chamber. The filtration velocity including air pollutants varied from 0.2 m/min to 0.4 m/min. Bag cleaning air pressure was set as $5.0kg_f/min$ for detaching dust cake from surface of filter bag. Bag cleaning interval at the filtration velocity of 0.2 m/min was around 3 times longer than that of the 0.4 m/min. The residual pressure drop maintained highest value at the highest filtration velocity. Fractional efficiency of 99.952%~99.971% was possible to maintain for the particle size of 2.5 microns. Total collection efficiency at the filtration velocity of 0.2 m/min was 99.42%. During this study we could confirm high collection efficiency and long cleaning intervals for the test with filtration velocity of 0.2 m/min indicating an optimal value for the given dimensions of the test unit and test operating conditions.