• 제목/요약/키워드: Aerosol processing

검색결과 43건 처리시간 0.033초

식품포장재내 비휘발성 잠재 이행물질들의 스크리닝을 위한 이차원크로마토 그래피와 범용검출기의 이용 (The Use of the Online Two-dimensional Liquid Chromatography Coupled with a Universal Detector for the Screening of Non-volatile Potential Migrants in Food Packaging Materials)

  • 윤찬석;이근택
    • 한국포장학회지
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    • 제16권1호
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    • pp.9-18
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    • 2010
  • For screening test of the non-volatile compounds which migrate from food packaging materials into foodstuffs, the traditional high performance liquid chromatography (HPLC) systems suffer from the lack of universal detector with high sensitivity and universality and high efficiency HPLC separation column which provides complete separation of complex mixtures into all individual substances. In this work, the use possibility of online two-dimensional liquid chromatography (2D-LC) system coupled with a charged aerosol detector (CAD), a universal detector, was reviewed. 2D-LC system permits to improve peak capacity and resolving power for complex mixtures. Charged aerosol detector (CAD) offers a new feasibility for detection of any non-volatile compounds with high sensitivity and constant response factor in a calibration range. The combination of size exclusion chromatography (SEC) and normal phase HPLC (NP-HPLC) is most frequently used for the separation of the natural and synthetic polymers which are mainly used as raw materials for the manufacture of food packaging materials. However, there is no commercial software available for data acquisition and handling and therefore the quantification in 2D-LC analysis is still rare.

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INCREASING TREND OF ANGSTROM EXPONENT OVER EAST ASIAN WATERS OBSERVED IN 1998-2005 SEAWIFS DATA SET

  • Fukushima, Hajime;Liping, Li;Takeno, Keisuke
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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    • pp.57-60
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    • 2007
  • Monthly mean data of ${\AA}ngstr{\ddot{o}}m$ exponent and Aerosol optical thickness (AOT) from Sea-viewing Wide Field-of-view Sensor (SeaWiFS) measurements over the East Asian waters were analyzed. Increasing trend of the satellite-derived ${\AA}ngstr{\ddot{o}}m$ exponent from 1998 to 2004 was found while AOT mean was observed stable during the same period. The trend of ${\AA}ngstr{\ddot{o}}m$ exponent is then interpreted as increase in fraction of small aerosol particles to give quantitative estimates on the variability of aerosols. The mean increase is evaluated to be $4{\sim}5%$ over the 7-year period in terms of the contribution of small particles to the total AOT, or sub-micron fraction (SMF). Possibilities of the observed trend arising from the sensor calibration or algorithm performance are carefully checked, which confirm our belief that this observed trend is rather a real fact than an artifact due to data processing. Another time series of SMF data (2000-2005) estimated from the fine-mode fraction (FMF) of Moderate Resolution Imaging Spectroradiometer (MODIS) supports this observation yet with different calibration system and retrieval algorithms.

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겨울철 광주지역 $PM_{2.5}$의 화학적 특성 조사 (Investigation of Chemical Characteristics of $PM_{2.5}$ during Winter in Gwangju)

  • 고재민;배민석;박승식
    • 한국입자에어로졸학회지
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    • 제9권2호
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    • pp.89-102
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    • 2013
  • 24-hr $PM_{2.5}$ samples were collected from January 19 through February 27, 2009 at an urban site of Gwangju and analyzed to determine the concentrations of organic and elemental carbon(OC and EC), water-soluble OC(WSOC), eight ionic species($Na^+$, $NH^{4+}$, $K^+$, $Ca^{2+}$, $Mg^{2+}$, $Cl^-$, ${NO_3}^-$ and ${SO_4}^{2-}$), and 22 elemental species. Haze phenomena was observed during approximately 29%(10 times) of the whole sampling period(35 days), resulting in highly elevated concentrations of $PM_{2.5}$ and its chemical components. An Asian dust event was also observed, during which $PM_{2.5}$ concentration was 64.5 ${\mu}g/m^2$. Crustal materials during Asian dust event contributed 26.6% to the $PM_{2.5}$, while lowest contribution(5.1%) was from the haze events. OC/EC and WSOC/OC ratios were found to be higher during haze days than during other sampling days, reflecting an enhanced secondary organic aerosol production under the haze conditions. For an Asian dust event, enhanced concentrations of OC and secondary inorganic components were also found, suggesting the further atmospheric processing of precursor gases during transport of air mass to the sampling site. Correlations among WSOC, EC, ${NO_3}^-$, ${SO_4}^{2-}$, and primary and secondary OC fractions, which were predicted from EC tracer method, suggests that the observed WSOC could be formed from similar formation processes as those of secondary organic aerosol, ${NO_3}^-$ and ${SO_4}^{2-}$. Results from principal component analysis indicate also that the observed WSOC was strongly associated with formation routes of the secondary organic and inorganic aerosols.

액적 표면에서 증발 및 응축을 고려한 곡면 형상 액적 제거장치의 제거 효율에 대한 수치 해석 (Numerical Analysis on Removal Efficiency of Water Droplets in a Curved Vane Mist Eliminator with Consideration of Evaporation and Condensation at Surface of Droplets)

  • 송동근
    • 한국입자에어로졸학회지
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    • 제12권4호
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    • pp.135-143
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    • 2016
  • Removal of water contents in a gas is needed in industrial field of gas processing related on energy production/conversion, and environmental treatment. Inertial separators are economic devices for separating droplets from the gas stream. For accurate understanding of removal process in a curved vane mist eliminator, a numerical model including turbulent dispersion, evaporation and condensation of water vapor at surface of droplets is required. A two-stage curved vane mist eliminator has been modeled, and fluid flow of mixture of air and water vapor and droplet trajectories were solved simultaneously with taking into account two-way coupling. Removal efficiency of droplets with various inlet condition of relative humidities (RH, 40%, 90%, and 100%) were compared. As RH increased, the effect of evaporation decreased and inertial separation efficiencies of droplets obtained increased especially for droplets of diameter below 10 micrometers.

Particle Deposition, PD Process - New Potential in Material Processing -

  • Fukumoto, Masahiro
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.47-48
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    • 2006
  • Oridinal thermal spray process has developed into two ways, namely, temperature dominated represented by plasma spraying, and velocity dominated represented by HVOF. It is common for both that the particle materials sprayed are basically in melted or half melted condition. New process has developed recently, that is, Cold Spray and Aerosol Deposition. Particle's heating is limited in CS lower than half of the material's melting point. Moreover, exactly no heating is loaded in AD process. Through the investigation on common feature for these three spraying processes, potential of new material process - Particle Deposition, PD - is considered and proposed.

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티타늄 가공에서 절삭력 분석을 위한 ADL 밀링 가공특성 (ADL Milling Characteristics for the Analysis of Cutting Force of Titanium Machining)

  • 한정식;정종윤
    • 산업경영시스템학회지
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    • 제45권3호
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    • pp.104-114
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    • 2022
  • The purpose of using coolant in machining is both to increase a tool life and also to prevent product deformation and thus, stabilize the surface quality by lubricating and cooling the tool and the machining surface. However, a very small amount of cutting mist should be used because chlorine-based extreme pressure additives are used to generate environmental pollutants in the production process and cause occupational diseases of workers. In this study, medical titanium alloy (Ti-6Al-7Nb) was subjected to a processing experiment by selecting factors and levels affecting cutting power in the processing of the Aerosol Dry Lubrication (ADL) method using vegetable oil. The machining shape was a slot to sufficiently reflect the effect of the cutting depth. As for the measurement of cutting force, the trend of cutting characteristics was identified through complete factor analysis. The factors affecting the cutting force of ADL slot processing were identified using the reaction surface analysis method, and the characteristics of the cutting force according to the change in factor level were analyzed. As the cutting speed increased, the cutting force decreased and then increased again. The cutting force continued to increase as the feed speed increased. The increase in the cutting depth increased the cutting force more significantly than the increase in the cutting speed and the feed speed. Through the reaction surface analysis method, the regression equation for predicting cutting force was identified, and the optimal processing conditions were proposed. The cutting force was predicted from the secondary regression equation and compared with the experimental value.

준 실시간 측정시스템을 이용한 미세입자 원소성분 배출특성 조사 (Emission Characteristics of Elemental Constituents in Fine Particulate Matter Using a Semi-continuous Measurement System)

  • 박승식
    • 한국대기환경학회지
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    • 제26권2호
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    • pp.190-201
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    • 2010
  • Fine particulate matter < $1.8{\mu}m$ was collected as a slurry using the Semicontinuous Elements in Aerosol Sampler with time resolution of 30-min between May 23 and 27, 2002 at the Sydney Supersite, Florida, USA. Concentrations of 11 elements, i.e., Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn, in the collected slurry samples were determined off-line by simultaneous multi-element graphite furnace atomic absorption spectrometry. Temporal profiles of $SO_2$ and elemental concentrations combined with meteorological parameters such as wind direction and wind speed indicate that some transient events in their concentrations are highly correlated with the periods when the plume from an animal feed supplement processing facility influenced the Sydney sampling site. The peaking concentrations of the elemental species during the transient events varied clearly as the plume intensity varied, but the relative concentrations for As, Cr, Pb, and Zn with respect to Cd showed almost consistent values. During the transient events, metal concentrations increased by factors of >10~100 due to the influence of consistent plumes from an individual stationary source. Also the multi-variate air dispersion receptor model, which was previously developed by Park et al. (2005), was applied to ambient $SO_2$ and 8 elements (Al, As, Cd, Cr, Cu, Fe, Pb, and Zn) measurements between 20:00 May 23 and 09:30 May 24 when winds blew from between 70 and $85^{\circ}$, in which animal feed processing plant is situated, to determine emission and ambient source contributions rates of $SO_2$ and elements from one animal feed processing plant. Agreement between observed and predicted $SO_2$ concentrations was excellent (R of 0.99; and their ratio, $1.09{\pm}0.35$) when one emission source was used in the model. Average ratios of observed and predicted concentrations for As, Cd, Cr, Pb, and Zn varied from $0.83{\pm}0.26$ for Pb to $1.12{\pm}0.53$ for Cd.

에어로졸 증착 공정으로 제조된 ZnO, AZO, ITO 박막의 특성과 유연 내구성 (Flexible Durability and Characteristics of ZnO, AZO and ITO Thin Films Grown by Aerosol Deposition Process)

  • 이동원;조명연;이상헌;김용남;이대석;구상모;오종민
    • 전기전자학회논문지
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    • 제21권4호
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    • pp.404-407
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    • 2017
  • 에어로졸 증착 공정을 이용하여 ZnO, AZO 및 ITO 막을 증착하고 코팅막의 미세구조, 광학적 및 전기적 특성을 연구하였다. 상온에서 PET 기판 위에 약 400 nm의 두께를 가지는 ZnO, AZO 및 ITO 막을 성공적으로 제조할 수 있었으며 캐리어 가스 유량이 증가하면서 ZnO, AZO 및 ITO 막의 광학적 특성 및 전기적 특성이 향상되었다. 기계적인 유연 내구성 시험에 있어 ZnO 막은 5,000회의 굽힘에도 파괴가 발생하지 않은 반면 AZO 및 ITO 막은 5000회 굽힘 시험 후 막의 파괴가 발생하고 투과도 및 저항의 성능이 저하되었다. 결론적으로 AZO 및 ITO 막의 성능은 ZnO 막에 비하여 약간 열세이나, 입자크기 제어 및 공정 최적화를 통해 성능을 향상시킬 수 있을 것으로 판단된다.

그래핀 옥사이드의 에어로졸 분무열분해 공정을 통한 면직물의 전기전도성 및 물성 평가 (Application and Functionalization of Graphene Oxide on Cotton Fabric Via Aerosol Spray Pyrolysis)

  • 엄현지;조길수
    • 한국의류산업학회지
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    • 제24권1호
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    • pp.138-145
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    • 2022
  • Today, graphene loaded textiles are being considered promising smart clothing due to their high conductivity. In this study, we reported reduced graphene oxide(r-GO) deposited pure cotton fabrics fabricated with a colloidal solution of graphene(GO), using a one-step aerosol spray pyrolysis(ASP) process and their potential application on smart textiles. The ASP process is advantageous in that it is easily implementable and can be applied for continuous processing. Moreover, this process has never been applied to deposit r-GO on pure cotton fabric. The field emission-scanning microscopy (FE-SEM) observation, Fourier transform-infrared(FT-IR) analysis, Raman spectroscopy, X-ray diffraction(XRD) analysis, and ultraviolet transmittance(UVT) were used to evaluate material properties of the r-GO colloids. The resistance was also measured to evaluate the electrical conductivity of the specimens. The results revealed that the r-GO was successfully deposed on specimens, and the specimen with the highest electrical conductivity demonstrated an electrical resistance value of 2.27 kΩ/sq. Taken together, the results revealed that the ASP method demonstrated a high potential for effective deposition of r-GO on cotton fabric specimens and is a prospect for the development of conductive cotton-based smart clothing. Therefore, this study is also meaningful in that the ASP process can be newly applied by depositing r-GO on the pure cotton fabric.

에어로졸, 수증기 측정 라만 레이저 레이다 시스템 개발 (Development of Raman Laser Radar System for Aerosol and Water Vapor Measurements)

  • 박찬봉;이영우
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2012년도 춘계학술대회
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    • pp.158-161
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    • 2012
  • 대기 중 에어로졸과 수증기 농도를 측정하기 위한 라만방식 레이저 레이다 시스템을 개발하였다. 송신시스템은 Nd:YAG laser 3rd harmonic Generator 및 빔 확대기로 구성되며, 대기 중에 송신되는 파장은 355 nm 이다. 수신시스템은 500 mm 망원경과 3채널 분광기, 광전자증배관 검출기 및 신호처리모듈로 구성되며 최종적으로 처리되는 신호의 파장은 355 nm. 387 nm, 그리고 408 nm 이다. 본 시스템은 대기권의 수증기의 수직 농도분포를 약 100~200 m 의 분해능과 3~4 km의 가 측정거리를 가지고 측정할 수 있다.

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