• Title/Summary/Keyword: Stable atmosphere

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Observation on Structural Change of Low Level Atmosphere due to Effect of Sea Breeze (해풍 효과에 의한 저층대기구조 변화의 측정)

  • 전병일;김유근
    • Journal of Environmental Science International
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    • v.5 no.4
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    • pp.441-451
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    • 1996
  • The surface meteorological and upper layer meteorological observation carried out to investigate influences of sea breeze effect on lower layer atmosphere at Gori nuclear power plant for 29∼30 July, 1996. According to surface meteorological data, the inflow of sea breeze was occurred 11:30 on 29 July, 10:30-on 30 July, respectively, at observation site. And the meteorological tower data showed that wind direction of sea breeze was identified as south-westerly, and wind speed of 58 m was 2 times stronger than that of 10 m. It is notworthy that surface inversion layer which built from the night time to daybreak of next day was not broken off by seab reeze's inflow for daytime, and strong inversion layer observed at 47∼243 m with moderately stable class (F) by URC. It was found that strong stable layer of potential temperature appeared at that layer, maximum relative humidity observed at the bottom of inversion layer and maximum mixing ratio observed in the low of inversion layer.

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Microstructural Characteristics of Al2O3/Cu Nanocomposites Depending on Fabrication Process (Al2O3/Cu 나노복합체 제조공정에 따른 미세조직 특성)

  • Kang, Kae-Myung;Oh, Sung-Tag
    • Korean Journal of Materials Research
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    • v.13 no.1
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    • pp.59-63
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    • 2003
  • The microstructural characteristics of $Al_2$$O_3$/Cu composites hot-pressed at different temperatures for atmosphere switching from $H_2$to Ar have been studied. When the composite atmosphere was switched at $1000^{\circ}C$ it led to more homogeneous microstructure than when the atmosphere was switched at $1450^{\circ}C$. The strong sensitivity of Cu to atmosphere, especially the oxygen content in the atmosphere, was found to be responsible for the observed change, based upon the interfacial phenomena related to the formation of $CuAlO_2$. The practical implication of these results is that an optimum processing condition for the design of homogeneous microstructure and stable properties can be established.

Effect of Controlled Atmosphere and Modified Atmosphere Storage on the Fatty Acid of Fresh and Red Ginseng (수삼의 CA 및 MA 저장이 홍삼의 지방산에 미치는 영향)

  • 전병선;최강주
    • Journal of Ginseng Research
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    • v.19 no.3
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    • pp.260-266
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    • 1995
  • Fifteen free fatty acids including myristic acid were isolated and identified from red ginseng processed from CA and MA stored fresh ginseng. Linoleic acid (80%) and palmitic acid (10.5%) content were the major components accounting for more than 90% of the total free fatty acid. The contents of free and identified fatty acids were not greatly changed in all the treatments. Especially when preservative was treated, the change of free fatty acid was quite stable over the control. Each fraction of neutral, glyco- and phospholipid was constant in terms of quantities before and after the treatment. Key words Controlled atmosphere, modified atmosphere, fresh ginseng, red ginseng, fatty acid.

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Flow Characteristics of the BPSG Film (BPSG막의 Flow 특성)

  • 홍성현;이종무;송성해
    • Journal of the Korean Ceramic Society
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    • v.26 no.3
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    • pp.381-389
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    • 1989
  • Effects of annealing temperature, time, and atmospehre on the flow characteristics of Atmospheric Pressure Chemical Vapor Deposition-borophosphosilicate glass were investigated. Stable step coverage can be obtained by annealing the BPSG film at 90$0^{\circ}C$ for 30 minutes in N2 atmosphere, but further heat treatment isnot effective. Flow characteristics of the BPSG film was better in steam atmosphere than in N2 atmosphere, and the factors which cause it were analyzed. The concentration of boron in the BPSG film was measured pretty accurately by FTIR spectrum. Boron content in the BPSG film was reduced by annealing treatment. The decrement of boron was greater in steam atmosphere than in the N2 atmosphere. Also it was found from the FTIR spectroscopic analysis that PH3 inhibited the oxidation of B2H6.

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Analysis on Vertical Structure of Sea Fog in the West Coast of the Korean Peninsula by Using Drone (드론을 활용한 한반도 서해 연안의 해무 연직구조 분석)

  • Jeon, Hye-Rim;Park, Mi Eun;Lee, Seung Hyeop;Park, Mir;Lee, Yong Hee
    • Atmosphere
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    • v.32 no.4
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    • pp.307-322
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    • 2022
  • A drone has recently got attention as an instrument for weather observation in lower atmosphere because it can produce the high spatiotemporal resolution weather data even though the weather phenomenon is inaccessible. Sea fog is a weather phenomenon occurred in lower atmosphere, and has observational limitations because it occurs on the sea. Therefore, goal of this study is to analyze the vertical structures about inflow, development and dispersion of sea fog using the high-resolution weather data with the meteorological sensor-equipped drone. This study observed sea fogs in the west coast of the Korean peninsula from March to October 2021 and investigated one sea fog inflowed into the coast on June 8th 2021. θe - qv diagrams (θe: equivalent potential temperature, qv: water vapor ratio) and vertical wind structures were analyzed. At inflow of sea fog, moist adiabatically stable layer was formed in 0-300 m and prevailing wind was switched from south-southwesterly to west-southwesterly under 120 m. Both changes are favorable for sea fog on the location. θe and qv plummeted in a layer 0-183 m. The inflowed sea fog developed from 183 m to 327 m by mixing with ambient atmosphere on top of sea fog. Also, strong mechanical turbulence near ground drove a vertical mixing under stable layer. At dispersion of sea fog, as θe on ground gradually increased, air condition was changed to neutral. Evaporation occurred on both bottom and top in sea fog. These results induced dissipation of sea fog.

The influence of atomosphere on high temperature crystal growth

  • Klimm, D.;Schroder, W.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.4
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    • pp.360-364
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    • 1999
  • The growth of crystals with high melting point$t_{fus}$$\geq$$1600^{\circ}C$ faces the researcher with experimental problems, as the choice of materials that withstand such high t is rather limited. Many metallic construction materials are in this high t range already molten or exhibit at least a drastically reduced mechanical strength. The very few materials with$t_{fus}$$1600^{\circ}C$ as e.g. W, Mo, and partially even Ir are more or less sensitive against oxygen upon heating. Whenever possible, high t crystal growth is performed under inert atmosphere (noble gases). Unfortunately, many oxides are not thermodynamically stable under such conditions, as reduction takes place within such atmosphere. A thoroughly search for suitable growth conditions has to be performed, that are on the one side "oxidative enough" to keep the oxides stable and on the other side "reductive enough" to avoid destruction of constructive parts of the crystal growth assembly. The relevant parameters are t and the oxygen partial pressure${po}_{2}$. The paper discusses quantitatively relevant properties of interesting oxides and construction materials and wasy to forecast theri behavior under growth conditions.

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Cool Island Intensity in a Large Urban Green in Downtown Daegu: Seasonal Variation and Relationship to Atmospheric Condition (대구 도심에 위치한 대규모 녹지공간의 냉섬 강도: 계절변화와 기상조건에의 관련성)

  • Park, Myong-Hee;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • v.19 no.1
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    • pp.81-87
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    • 2010
  • Cool island intensity urban green space was investigated based in Dalsung Park, that is one of the largest parks in Daegu. Cool island intensity(CII), which is defined as the temperature difference between the green space and its surrounding built-up areas, shows time variations. A through-year measurement(2008-2009) of ground level air temperature revealed seasonal variation and relationship to the atmospheric condition of CII. The temperature variation in the park and the reference downtown Daegu was as same order as CII. The noontime CII is larger in summer than that in winter due to the leaf fall of the park trees. On the other hand, seasonal variation of nighttime CII is not so clear. The nighttime CII was larger under the stable atmosphere.

The Influence of Atmostphere on High Temperature Crystal Growth

  • Klimm, D.;Schroder, W.
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1999.06a
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    • pp.51-67
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    • 1999
  • The growth of crystals with high melting points tfus$\geq$1$600^{\circ}C$ faces the researcher with experimental problems, as the choice of materials that withstand such high t is rather limited. Many metallic construction materials are in this high t range already molten or exhibit at least a drastically reduced mechanical strength. The very few materials with tfus》1$600^{\circ}C$ as e.g. W, Mo, and partially even Ir are more or less sensitive against oxygen upon heating. Whenever possible, high t crystal growth is performed under inert atmosphere (noble gases). Unfortunately, any oxides are not thermodynamically stable under such conditions, as reduction takes place within such atmosphere. A thoroughly search for suitable growth conditions has to be performed, that are on the one side "oxidative enough" to keep the oxides stable and on the other side "reductive enough" to avoid destruction of constructive parts of the crystal growth assembly. The relevant parameters are t and the oxygen partial pressure pO2. The paper discusses quantitatively relevant properties of interesting oxides and construction materials and ways to forecast their behavior under growth conditions.r growth conditions.

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An investigation of characteristics of Au plating for telecommunication components (통신기자재용 금도금 특성 분석 연구)

  • 한전건;강태만
    • Journal of the Korean institute of surface engineering
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    • v.25 no.6
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    • pp.309-317
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    • 1992
  • Evaluation of electroplated gold has been carried out to obtain the data base for electrical, mechanical and environmental properties for telecommunication component applications. Gold plating was performed to a various thickness of $0.1\mu\textrm{m}$ to 1.$25\mu\textrm{m}$ after Ni plating of $3\mu\textrm{m}$ on C52100 bronze. Electrical properties were evaluated by measuring contact resistance using 4-wire method under static contact and dynamic contact during wear. Reciprocating wear test was performed to study the wear behavior as well as failure of gold contacts. Environmental characteristics were evaluated by using salt spray testing and SO2 test. Hardness of soft gold film was measured to be 53KHN under 5g load. Friction coefficient was initially obtained to be 0.15 and 0.25 under 100g and 200g loads respectively, and then raised up to 0.8 with increasing reciprocating wear cycles. Static contact resistance was 2 to 3m$\Omega$ regardless of gold film thickness while drastic changes of contact resistance were occured upon stripping of the gold film during wear. The lifetime of contact wear showing stable contact resistance increased up to 6 times for $1\mu\textrm{m}$ thickness compared to that of$ 0.1\mu\textrm{m}$ thickness under 100g load. All gold plating appeared to be stable under salt atmosphere while only the gold plating over 1$\mu\textrm{m}$ was stable under SO2 atmosphere.

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The Development of Textile Pattern Designs for Car Seats Using Patterns Expressed on Nineteenth-century Blue and White Porcelain (19세기 청화백자에 표현된 문양을 활용한 자동차 시트 직물 패턴디자인 개발)

  • Jung, Jin-Soun
    • Fashion & Textile Research Journal
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    • v.24 no.4
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    • pp.372-385
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    • 2022
  • In this study, the patterns expressed on nineteenth-century blue and white porcelain among Joseon white porcelain were selected as the material for the development of the car seat fabric design. It was intended to be applied to car seat design by incorporating Korea's own traditional patterns to fit modern sensibility. First, seven pieces of nineteenth-century blue and white porcelain were selected through the literature, and motifs were produced using adobe illustrator, a computer graphic program. Seven car seat fabric designs were developed according to the construction method and development method of the produced motif. Work 1 was designed to elicit a soft and feminine atmosphere using the peony pattern shown in Table 1-1. Work 2 aimed to express a luxurious atmosphere using the image of the mountain expressed in Table 1-2 as a design material. Works 3 was designed by freely arranging the letters of luck expressed in Table 1-3 to form a free and dynamic image. Work 4 was intended to express a stable and rhythmic atmosphere by horizontally arranging the images of the gently curved wings, tail, and rhythmical tail feathers of the phoenix expressed in Table 1-4. Work 5 was designed in a vertical arrangement using the patterns and silhouettes of the tiger's back expressed in Table 1-5. Work 6 was designed using the wave pattern expressed in Table 1-6 to replicate the rhythmic atmosphere. Work 7 was designed using the images of rocks, waves, and the sun in Table 1-7 to express a calm and antique atmosphere.