• 제목/요약/키워드: Neutral gas

검색결과 374건 처리시간 0.032초

Volatile Components of Korean Soybean Paste Produced by Bacillus subtilis PM3

  • JONG-KYU KIM;JI, WON-DAE;SUNG-HO YANG;MYEONG-RAK CHOI
    • Journal of Microbiology and Biotechnology
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    • 제5권3호
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    • pp.143-148
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    • 1995
  • A strain producing soybean paste flavor was isolated from traditional Korean soybean paste. The isolate was identified as Bacillus subtilis PM3. The neutral fraction representing the traditional soybean paste aroma was obtained from the whole volatile components produced by B. subtilis PM3 in cooked soybean. Each separated peak from the neutral fraction of gas chromatogram was identified by gas chromatography-mass spectrometry (GC/MS) and Kovat's retention index, and the aromas of each peak were investigated by a sniffing test with the exercise panel. The twenty-nine components, including six character impact compounds and twelve components of flavors of Korean soybean paste, were confirmed. Some regions of gas chromatogram represented the soybean paste odor. It has been confirmed that traditional Korean soybean paste can be manufactured with the strain B. subtilis PM3.

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WATER VAPOR MASERS: A SIGNPOST FOR LOW MASS STAR FORMATION

  • Migenes, V.;Trinidad, M.A.;Valdettaro, R.;Brand, J.;Palla, F.
    • 천문학회지
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    • 제40권4호
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    • pp.127-129
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    • 2007
  • It is well known that water vapor maser emission at 22.2 GHz is associated with the earliest stages of both low- and high-mass star formation and it can be considered a reliable diagnostic of their evolutionary state. Bright Rimmed Clouds (BRCs) are clouds that have been compressed by an external ionization-shock front which focuses the neutral gas into compact globules. The boundary layer between the neutral gas and the gas ionized by the incident photons is often called "bright rim" but the clumps are sometimes classified also as speck globules or cometary globules depending on their appearance. Small globules with bright rims have been considered to be potential sites of star formation and have been studied in several individual regions. We present results from high resolution VLA observations searching for new candidates of recent star formation in bright-rimmed clouds/globules associated with IRAS point sources.

Gas Barrier Properties of Nanolaminated Single Inorganic Film Deposited by Neutral Beam Assisted Sputtering Process

  • Jang, Yun-Sung;Lee, You-Jong;Hong, Mun-Pyo
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.465-465
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    • 2012
  • In this study, we developed an Al2O3 nanolaminated single gas barrier layer using a Neutral Beam Assisted Sputtering (NBAS) process. The NBAS process can continuously change crystalline structures from an amorphous phase to a nanocrystal phase with various grain sizes and lead to the formation of a nanolaminated structure in the single inorganic thin film. As a result, the water vapor transmission rates (WVTR) of the nanolaminated Al2O3 thin films by NBAS process have improved more than 40% compared with that of conventional Al2O3 layers by the RF magnetron sputtering process under the same sputtering conditions.

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Development of RF Ion Source for Neutral Beam Injector in Fusion Devices

  • 장두희;박민;김선호;정승호
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.550-551
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    • 2013
  • Large-area RF-driven ion source is being developed at Germany for the heating and current drive of ITER plasmas. Negative hydrogen (deuterium) ion sources are major components of neutral beam injection systems in future large-scale fusion experiments such as ITER and DEMO. RF ion sources for the production of positive hydrogen ions have been successfully developed at IPP (Max-Planck- Institute for Plasma Physics, Garching) for ASDEX-U and W7-AS neutral beam injection (NBI) systems. In recent, the first NBI system (NBI-1) has been developed successfully for the KSTAR. The first and second long-pulse ion sources (LPIS-1 and LPIS-2) of NBI-1 system consist of a magnetic bucket plasma generator with multi-pole cusp fields, filament heating structure, and a set of tetrode accelerators with circular apertures. There is a development plan of large-area RF ion source at KAERI to extract the positive ions, which can be used for the second NBI (NBI-2) system of KSTAR, and to extract the negative ions for future fusion devices such as ITER and K-DEMO. The large-area RF ion source consists of a driver region, including a helical antenna (6-turn copper tube with an outer diameter of 6 mm) and a discharge chamber (ceramic and/or quartz tubes with an inner diameter of 200 mm, a height of 150 mm, and a thickness of 8 mm), and an expansion region (magnetic bucket of prototype LPIS in the KAERI). RF power can be transferred up to 10 kW with a fixed frequency of 2 MHz through a matching circuit (auto- and manual-matching apparatus). Argon gas is commonly injected to the initial ignition of RF plasma discharge, and then hydrogen gas instead of argon gas is finally injected for the RF plasma sustainment. The uniformities of plasma density and electron temperature at the lowest area of expansion region (a distance of 300 mm from the driver region) are measured by using two electrostatic probes in the directions of short- and long-dimension of expansion region.

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Al2O3 High Dense Single Layer Gas Barrier by Neutral Beam Assisted Sputtering (NBAS) Process

  • 장윤성;홍문표
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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    • pp.157-157
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    • 2015
  • Recently, the growing interest in organic microelectronic devices including OLEDs has led to an increasing amount of research into their many potential applications in the area of flexible electronic devices based on plastic substrates. However, these organic devices require a gas barrier coating to prevent the permeation of water and oxygen because organic materials are highly susceptible to water and oxygen. In particular, high efficiency OLEDs require an extremely low water vapor transition rate (WVTR) of $1{\times}10^{-6}g/m^2day$. The Key factor in high quality inorganic gas barrier formation for achieving the very low WVTR required ($1{\times}10^{-6}g/m^2day$) is the suppression of defect sites and gas diffusion pathways between grain boundaries. In this study NBAS process was introduced to deposit enhanced film density single gas barrier layer with a low WVTR. Fig. 1. shows a schematic illustration of the NBAS apparatus. The NBAS process was used for the $Al_2O_3$ nano-crystal structure films deposition, as shown in Fig. 1. The NBAS system is based on the conventional RF magnetron sputtering and it has the electron cyclotron resonance (ECR) plasma source and metal reflector. $Ar^+$ ion in the ECR plasma can be accelerated into the plasma sheath between the plasma and metal reflector, which are then neutralized mainly by Auger neutralization. The neutral beam energy is controlled by the metal reflector bias. The controllable neutral beam energy can continuously change crystalline structures from an amorphous phase to nanocrystal phase of various grain sizes. The $Al_2O_3$ films can be high film density by controllable Auger neutral beam energy. we developed $Al_2O_3$ high dense barrier layer using NBAS process. We can verified that NBAS process effect can lead to formation of high density nano-crystal structure barrier layer. As a result, Fig. 2. shows that the NBAS processed $Al_2O_3$ high dense barrier layer shows excellent WVTR property as a under $2{\times}10^{-5}g/m^2day$ in the single barrier layer of 100nm thickness. Therefore, the NBAS processed $Al_2O_3$ high dense barrier layer is very suitable in the high efficiency OLED application.

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Nutritional Evaluation of Some Tropical Crop Residues: In Vitro Organic Matter, Neutral Detergent Fibre, True Dry Matter Digestibility and Metabolizable Energy Using the Hohenheim Gas Test

  • Aregheore, E.M.;Ikhatua, U.J.
    • Asian-Australasian Journal of Animal Sciences
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    • 제12권5호
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    • pp.747-751
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    • 1999
  • The Hohenheim in vitro gas test was used to assess the nutritional value of some crop residues of known in vivo digestibility. The crop residues are groundnut shells (GNS) corn cobs (CC); cassava peels (CaP); unripe and ripe plantain peels (UPP, RPP) and citrus pulp/peels (CPP). Compared to other crop residues, crude protein (CP) content of CC was low. Except for CaP and CPP that had low neutral detergent fibre (NDF) and acid detergent fibre (ADF), other residues contained a high amount of cell wall constituents. Net gas production was significantly different among the crop residues (p<0.05). Gas production was highest in CPP followed by CaP. CC, UPP and RPP have the same volume of net gas production, while the least net gas production was in GNS. True dry matter (TDM) digestibility was significantly different (p<0.05) among the residues. GNS was the least in TDM digestibility. CaP, UPP and RPP had similar TDM digestibility values, while the highest TDM digestibility was obtained in CPP. OM digestibility was different among the residues (p<0.05). CaP and CPP had the same ME value while CC, UPP and RPP had close ME values and GNS the least in ME (p<0.05). The potential extent (b) and rate (c) of gas production were statistical different among the residues (p<0.05). The Hohenheim gas test gave high in vitro organic matter (OM) digestibility for CC, CaP, UPP and RPP and CPP. Fermentable carbohydrates and probably available nitrogen in the crop residues influenced net gas production. The results showed that crop residues besides, providing bulk are also a source of energy and fermentable products which could be used in ruminant livestock production in the tropics.

담배 이분 중 Essential Oil의 활용 연구 (제1보) - 정유의 향끽미 증진 성분에 관하여 - (A Study on the Use of Essential Oil from Tobacco Powder (I) - On the Flavouring Agent in Essential Oil Components -)

  • 이경구;박진우
    • 한국연초학회지
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    • 제4권2호
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    • pp.67-73
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    • 1982
  • Essential oil components from tobacco powder were investigated as flavouring agent. The essential oil was isolated from tobacco powder by a simple distillation /extraction method The extracted essential oil was fractionated into basic, acidic and neutral groups. And the neutral group of essential oil was separated by column chromatography into 10 fractions. Above groups and fractions were tested for tobacco aroma and smoke aroma. The neutral group except most nonpolar fraction displays good flavouring properties which make them highly suitable for improving the flavour and aroma of tobacco and tobacco smoke. The most nonpolar fraction from neutral group was carefully investigated using preparative column, thin layer and gas chromatography ailed by GC/MS coupling. The major subfraction was identified as hydrocarbons on the basis of the IR spectrum. The 58 hydrocarbon components were identified by their mass spectra and was chromatographic retention times.

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The Effects of Nitrite Treatment on the Lipid Composition, Fatty Acid Composition, and Susceptibility to Oxidation of Pork Biceps Femoris Muscle

  • Han, S.K.;Yamauchi, K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제13권12호
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    • pp.1764-1769
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    • 2000
  • The purpose of this experiment was to investigate the antioxidant effect of nitrite on total, neutral, and polar lipids and fatty acid composition in laboratory-cooked ground pork. Muscle samples (Biceps femoris) were analyzed using Iatroscan, gas chromatography, phosphorus content, and TBARS value. The total and neutral lipid contents of muscle were higher in nitrite-untreated meat (0 ppm) than in nitrite-treated meat (100 ppm) but the reverse was observed for polar lipid contents. The results for neutral lipids showed a similar trend when compared with total lipids. Polyunsaturated fatty acids contents of total, neutral and polar lipid in 100 ppm treated meat were higher than that of 0 ppm. The phosphorus content was higher in 100 ppm meat than in 0 ppm but the reverse was observed for TBARS value. These results showed that the addition of 100 ppm nitrite to ground pork resulted in a remarkable antioxidant effect during refrigeration storage.

Neutral Beam Evolution in the KSTAR NBI Test Stand

  • In, S.R.;Shim, H.J.
    • Journal of Korean Vacuum Science & Technology
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    • 제7권1호
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    • pp.1-7
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    • 2003
  • The pressure distributions in the test stand built for developing KSTAR NBI ion sources were obtained using a network system composed of conductance elements modeling the ion source, the neutralizer, and other beam line components. The allowable regime was defined on the coordinates of the gas supply rate to the ion source and the neutralizer, considering the proper conditions of the three critical parameters, the ion source pressure for good arc discharge, the pressure integral in the neutralizer for sufficient neutralization, and the chamber pressure for minimum neutral beam loss. The neutral beam evolution along the path from the ion source extraction grid to the calorimeter through the neutralizer, the bending magnet and the vacuum chamber was estimated for typical pressure distributions.

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글로벌 모델에 의한 저온 고밀도 플루오로카본 플라즈마 특성의 공정변수 의존성 해석 (Analysis of Process Parameter dependency on the characteristics of high density fluoro carbon plasma using global model)

  • 이호준;태흥식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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    • pp.879-881
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    • 1999
  • Radical and ion densities in a CF4 plasma have been calculated as a function of input power density. 9as pressure and feed gas flow rate using simple 0 dimensional global model. Fluorine atom is found to be the most abundant neutral particle. Highly fragmented species such as CF and CF+ become dominant neutral and ionic radical at the high power condition. As the pressure increases. ion density increases but ionization rate decreases due to the decrease in electron temperature. The fractional dissociation of CF4 feed gas decreases with pressure after increasing at the low pressure range. Electron density and temperature are almost independent of flow rate within calculation conditions studied. The fractional dissociation of CF4 monotonically decreases with flow rate. which results in increase in CF3 and decrease in CF density. The calculation results show that the SiO2 etch selectivity improvement correlates to the increase in the relative density of fluorocarbon ion and neutral radicals which has high C/F ratio.

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