• Title/Summary/Keyword: volatile materials

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An Experimental Study of Dilution Methods for Preventing Volatile Particle Generation during Measurement of Diesel Particle Number Concentration (디젤 극미세입자 개수 농도 측정시 Volatile Particle 생성을 억제할 수 있는 희석방법에 관한 실험적 연구)

  • Yim, Tae-Ho;Kim, Hong-Suk;Cho, Hyoung-Mun;Lee, Jin-Wook;Jeong, Young-Il;Jeon, Heung-Shin
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.5
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    • pp.67-73
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    • 2009
  • Recently, Europe decided to start the regulation of diesel engine nanoparticles because of its well known adverse health effects. The diesel nanoparticles can be classified as solid carbon particles and volatile particles. The volatile particles generates during dilution process by condensation of gas phase volatile compounds such as hydrocarbon. The new nanoparticle regulation considers only solid particles because of difficulty of measurement of volatile particles. The aim of this study is to suggest a proper dilution method that prevent the volatile particle generation. As a result, it is found that the $1^{st}$ dilution air temperature should be above $120^{\circ}C$ in order to prevent volatile particle generation effectively. It is also found that the volatile particles can be removed effectively in the evaporation tube by the increase of evaporation tube temperature. But when exhaust gas is hot enough (>$190^{\circ}C$, in this study) and it is diluted in the first diluter with high temperature air (>$120^{\circ}C$), removal phenomenon of volatile particles by increasing of evaporation tube temperature can not be seen. It means that there are no volatile particles in the diluted exhaust gas. Additionally, dilution ratio is not an important factor for volatile particle generation compared with dilution air temperature or evaporation tube temperature.

Recent Development in Polymer Ferroelectric Field Effect Transistor Memory

  • Park, Youn-Jung;Jeong, Hee-June;Chang, Ji-Youn;Kang, Seok-Ju;Park, Cheol-Min
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.8 no.1
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    • pp.51-65
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    • 2008
  • The article presents the recent research development in polymer ferroelectric non-volatile memory. A brief overview is given of the history of ferroelectric memory and device architectures based on inorganic ferroelectric materials. Particular emphasis is made on device elements such as metal/ferroelectric/metal type capacitor, metal-ferroelectric-insulator-semiconductor (MFIS) and ferroelectric field effect transistor (FeFET) with ferroelectric poly(vinylidene fluoride) (PVDF) and its copolymers with trifluoroethylene (TrFE). In addition, various material and process issues for realization of polymer ferroelectric non-volatile memory are discussed, including the control of crystal polymorphs, film thickness, crystallization and crystal orientation and the unconventional patterning techniques.

The Characteristic of Volatile Organic Compounds(VOCs) Emission from the Type of Indoor Building Materials as the Temperature and Humidity (온.습도에 따른 건축 내장재별 휘발성유기화합물의 방출특성)

  • Seo, Byeong-Ryang;Kim, Shin-Do;Park, Seong-Kyu
    • Journal of Environmental Health Sciences
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    • v.32 no.4 s.91
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    • pp.292-303
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    • 2006
  • The Volatile Organic Compounds(VOCs) are emitted from various sources and have lots of different form. Recently human are spending the many times at indoor area and indoor air pollution is issued the important social problem. The emission sources of indoor air pollutants are very various, also indoor building materials are composed of very complex chemical compounds, these indoor building materials discharge very much VOCs and other hazardous compounds. In this study, we performed the small chamber test to investigate the VOCs emission concentration and characteristics involving five kinds of the indoor building materials(furniture material, wooden floor, wall paper, paint and tile) under different conditions of four temperature and relative humidity as account of the air flow rate(AFR), air exchange rate(AER), loading factor and air velocity respectively. As the result, It was showed that building materials are emitted the highest VOCs concentration at the beginning of experiment and furniture material is emitted the highest VOCs concentration. Most of the materials were affected by temperature, but paint and tile material were affected by humidity.

Detection of Volatile Organic Compounds (VOCs) using Organic-Inorganic Hybrid Perovskite Nanoparticles (유무기 페로브스카이트 나노입자의 휘발성 유기화합물 감응특성)

  • Choi, Hansol;Choi, Jihoon
    • Korean Journal of Materials Research
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    • v.30 no.10
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    • pp.515-521
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    • 2020
  • Organic-inorganic hybrid perovskite nanocrystals have attracted a lot of attention owing to their excellent optical properties such as high absorption coefficient, high diffusion length, and photoluminescence quantum yield in optoelectronic applications. Despite the many advantages of optoelectronic materials, understanding on how these materials interact with their environments is still lacking. In this study, the fluorescence properties of methylammonium lead bromide (CH3NH3PbBr3, MAPbBr3) nanoparticles are investigated for the detection of volatile organic compounds (VOCs) and aliphatic amines (monoethylamine, diethylamine, and trimethylamine). In particular, colloidal MAPbBr3 nanoparticles demonstrate a high selectivity in response to diethylamine, in which a significant photoluminescence (PL) quenching (~ 100 %) is observed at a concentration of 100 ppm. This selectivity to the aliphatic amines may originate from the relative size of the amine molecules that must be accommodated in the perovskite crystals structure with a narrow range of tolerance factor. Sensitive PL response of MAPbBr3 nanocrystals suggests a simple and effective strategy for colorimetric and fluorescence sensing of aliphatic amines in organic solution phase.

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 (식품포장재내 비휘발성 잠재 이행물질들의 스크리닝을 위한 이차원크로마토 그래피와 범용검출기의 이용)

  • Yoon, Chan-Suk;Lee, Keun-Taik
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.16 no.1
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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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Overview of the Current Status of Technical Development for a Highly Scalable, High-Speed, Non-Volatile Phase-Change Memory

  • Lee, Su-Youn;Jeong, Jeung-Hyun;Cheong, Byung-Ki
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.8 no.1
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    • pp.1-10
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    • 2008
  • The present status of technical development of a highly scalable, high-speed non-volatile PCM is overviewed. Major technical challenges are described along with solutions that are being pursued in terms of innovative device structures and fabrication technologies, new phase change materials, and new memory schemes.