• Title/Summary/Keyword: 온도분포특성

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삼중탐침과 단일탐침에 의한 RF, DC, RF+DC 플라즈마의 특성비교

  • 최용섭;정규선;장두희;심연근;김진희
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.11b
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    • pp.675-680
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    • 1996
  • 필라멘트 직류 가열 방식에 의한 DC 플라즈마, Capacitive RF 플라즈마, 그리고 DC+RF 혼성 플라즈마를 발생시켜서, 삼중탐침과 단일탐침으로 측정비교하여 다음과 같은 결과를 얻었다. 또한 두 개의 온도분포가 존재할 때 단일 탐침과 삼중탐침을 비교하여 삼중탐침이 energetic electron 포집함을 알 수 있었다.

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Cryo-grinding Characteristics of Frozen Fish Meat at Different Temperature (동결온도에 따른 어육의 동결마쇄특성)

  • HONG Sang-Pill;YANG Seung-Yong;LEE Nam-Hyuk;KIM Dong-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.29 no.5
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    • pp.578-585
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    • 1996
  • Cryo-grinding process comprising hammer mill-shattering and colloid mill-grinding without refrigerant was applied to sardine, pollack and squid muscle frozen at $-20^{\circ}C,\;-40^{\circ}C\;and\;-80^{\circ}C$, respectively and its characteristics were investigated. Particle size distribution of shattered product was shown larger in the order of squid, sardine and pollack and particle size of shattered product frozen at $-80^{\circ}C$ was shown smaller than those at $-40^{\circ}C$. Image of shattered product depended on freezing temperatures and fish species, suggesting particle size distribution of rheological properties can be dependent on fish species or freezing temperature. Yield of cryo- grinded product was in the range of $52.5\~62.5\%$ and Ca content of sardine or pollack product was $6\~8$ times higher than its fillet. Emulsion capacity of cryogrinded product was not decreased during processing. Therefore, this method is thought to be applicable to fish precessing, and preparation of fish paste or powaer.

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Climatological Characteristics in the Variation of Soil temperature in Korea (우리나라 지중온도 변동의 기후학적 특성)

  • Kim Seoung-Ok;Suh Myoung-Seok;Kwak Chong-Heum
    • Journal of the Korean earth science society
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    • v.26 no.1
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    • pp.93-105
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    • 2005
  • Climatological characteristics in the variation of soil temperatures in Korea were investigated using Korea Meterological Administration's observation data. And the impacts of soil moisture on the variation of soil temperature were examined using observed precipitation data. The climatological averages of soil temperatures are ranged from 14.4 to $15.0^{\circ}C$ regardless of depths. And they showed an latitudinal gradient with a warm temperature at the southern region and 'U' shape as in the air temperature with a high value along the coastal region. The relatively higher heat capacity and low conductivity of soil compared to those of the air resulted in the significant delay of the maximum and minimum date with depth. As a results, soil acts as a heat source during winter while a heat sink during summer. Global warming and urban heat island have increased the soil temperatures with an average rate $0.3\~0.5^{\circ}C/10-year$ as in the air temperature during last 30 years $(1973\~2002)$. However, the warming rate is maximized during spring contrary to the winter in the air temperature. The temporal variation of soil temperatures is strongly affected by that of soil moisture through an modification of the heat capacity and heat convection. In general, the increased soil moisture clearly decreased the temporal variations and increased the deep layer soil temperatures during cold season.

Ignition Characteristics of n-Dodecane Fuel Droplet on a Hot Surface (n-Dodecane 연료의 고온면 점화특성)

  • Kim, Sung-Chan
    • Fire Science and Engineering
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    • v.24 no.1
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    • pp.116-121
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    • 2010
  • The present study has been performed to investigate the ignition characteristics of a n-dodecane fuel droplet on the hot surface. Simplified bench scale test setup was built to examine the effect of air flow on the ignition temperature of fuel droplet. IR pyrometric sensor was used to measure the surface temperature, the measured temperature using IR pyrometer was directly compared with k-type thermocouple. The ignition of n-dodecane fuel droplet was divided into two stage - cool flame and hot flame - with the air flow rate except the case of air flow rate 3.0 lpm. The ignition temperature and probability was greatly affected by the air flow rate and the MHSIT of the present study was about $300^{\circ}C$ for air flow rate of 0.5 lpm.

An Analysis on the Changes of the Surface Hydrological Parameters using Landsat TM Data (Landsat TM 자료를 이용한 지표면 수문인자 변화 분석)

  • Chae, Hyo-Sok;Song, Young-Soo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.2 no.3
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    • pp.46-59
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    • 1999
  • Remote sensing provides informations on the changes of the hydrological states and variables over with the temporal and spatial distribution to monitor hydrological conditions and changes for large area. Especially, it can extract a spatial distribution of hydrological parameters such as surface albedo, vegetation informations, and surface temperature to effectively manage water resources of the watershed. In this study, we analyzed the characteristic of temporal and spatial changes in surface hydrological parameters which is necessary to identify the spatial distribution of water resources. 5 Landsat TM data of 1995 which is collected for Bochong-chon watershed, located in the upper stream of Keum River, were used to estimate characteristics on the change of hydrological parameters and atmospheric correction was carried out using COST model. The study showed that the difference of the albedo by the land cover was very sensitive depending upon the change of sun elevation and the amount of water in the soil. The difference between the surface temperature analysis and the measured air temperature was from $2.5^{\circ}C$ to $3.86^{\circ}C$.

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Effect of RF Bias on Electron Energy Distributions and Plasma Parameters in Inductively Coupled Plasma (유도 결합 플라즈마에서 플라즈마 변수와 전자 에너지 분포에 대한 극판 전력 인가의 영향)

  • Lee, Hyo-Chang;Chung, Chin-Wook
    • Journal of the Korean Vacuum Society
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    • v.21 no.3
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    • pp.121-129
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    • 2012
  • RF biased inductively coupled plasma (ICP) is widely used in semiconductor and display etch processes which are based on vacuum science. Up to now, researches on how rf-bias power affects have been focused on the controls of dc self-bias voltages. But, effect of RF bias on plasma parameters which give a crucial role in the processing result and device performance has been little studied. In this work, we studied the correlation between the RF bias and plasma parameters and the recent published results were included in this paper. Plasma density was changed with the RF bias power and this variation can be explained by simple global model. As the RF bias was applied to the ICP, increase in the electron temperature from the electron energy distribution was measured indicating electron heating. Plasma density uniformity was enhanced with the RF bias power. This study can be helpful for the control of the optimum discharge condition, as well as the basic understanding for correlation between the RF bias and plasma parameters.