• 한국환경과학회지
• /
• 제22권1호
• /
• pp.119-129
• /
• 2013

We compared equilibrium evaporation($E_{equili}$) eddy-covariance($E_{eddy}$) with soil moisture data($E_{SMseries}$) which were measured with a 2 hours sampling interval at three points for a humid forest hillslope from May 5th to May 31th in 2009. Accumulations of $E_{eddy}$, $E_{equili}$ for the study period were estimated as 2.52, 3.28 mm and those of $E_{SMseries}$ were ranged from 1.91 to 2.88 mm. It suggested that the eddy-covariance method considering the spatial heterogeneity of soil evaporation is useful to evaluate the soil evaporation. Method A, B and C were proposed using mean meterological data and daily moisture variation and the computations were compared to eddy-covariance method and equilibrium evaporation. The methods using soil moisture data can describe the variations of soil evaporation from eddy-covariance through simple moving average analysis. Method B showed a good matched with eddy-covariance method. This indicated that Dry Surface Layer (DSL) at 14:00 which was used for method B is important variable for the evaluation of soil evaporation. The total equilibrium evaporation was not significantly different to those of the others. However, equilibrium evaporation showed a problem in estimating soil evaporation because the temporal tendency of $E_{equili}$ was not related with the those of the other methods. The improved understanding of the soil evaporation presented in this study will contribute to the understandings of water cycles in a forest hillslope.

• Journal of Mechanical Science and Technology
• /
• 제18권12호
• /
• pp.2104-2113
• /
• 2004

Surface degreasing method with premixed flame is proposed as the removal method of adherent impurities on materials. Effects of adherent molecular thickness and surface potential energy on evaporation rate of adherent molecules and molecular evaporation mechanism were investigated and discussed in the present study. Evaporation processes of adherent molecules on surface molecules were simulated by the molecular dynamics method to understand thermal phenomena on evaporation processes of adherent molecules by using high temperature gas like burnt gas. The calculation system was composed of a high temperature gas region, an adherent molecular region and a surface molecular region. Both the thickness of adherent molecules and potential parameters affceted the evaporation rate of adherent molecules and evaporation mechanism in molecular scale.

• 한국농림기상학회지
• /
• 제4권4호
• /
• pp.197-202
• /
• 2002

A new method is used to estimate the amount of water evaporation from Class A Pan with higher precision and accuracy. The principle of method is to detect the weight change of a buoyant sinker resulting from a change in water level of Class A Pan. A strain-gauge load cell is used to measure the weight change. Field observation of evaporation was done at Pohang Meteorological Station from June 24 to August 4, 2002. By using this new method, it is possible to measure hourly evaporation accurately even under a strong solar radiation and wind disturbance, enabling a direct comparison of evaporation with other meteorological elements. At night, under low humidity and high wind speed conditions, more evaporation was recorded than during daytime. Maximum evaporation rates observed during this period exceed 1.0 mm/hour under the sunny and windy conditions with low humidity. To understand relationships between meteorological elements and latent heat flux at ground level, we suggest intensive held experiments using high accuracy evaporation recording instruments with hourly time interval.

• 열처리공학회지
• /
• 제14권3호
• /
• pp.151-154
• /
• 2001

$TiO_2$ thin film has wide application because of its high capacitanca, reflection, and good transmissivity in visible range. $TiO_2$ thin film can be made by thermal deposition method, reactive evaporation method, activated reactive evaporation(ARE) method. In the case of thermal deposition, the oxygen deficiency can occur because the melting point of Ti is very high. While in the case of reactive evaporation, high density $TiO_2$ can not be made, because reactive gas($O_2$) and evaporated material(Ti) are not fully combined, activated reactive evaporation, $TiO_2$ is easily deposited at lower gas pressure compared with reactive evaporation because the ionized reactive gas is made by plasma. Therefore, activated reactive evaporation is very useful to deposit the material having the high melting point. In this work, we formed $TiO_2$ thin film by activated reactive evaporation method. The surface of $TiO_2$ thin film was analyzed by X-ray photoelectron spectroscopy. The surface morphology which was analyzed by atomic force microscopy(AFM) shows that feature of the film surface is uniform. The dielectric capacitance, withstanding voltage were $600{\mu}F/cm^2$, 0.4V respectively. In further work, we can increase the withstanding voltage by improving the deposition parameter of substrates.

• 대한전자공학회논문지SD
• /
• 제44권11호
• /
• pp.43-50
• /
• 2007

ITO(Indium Tin Oxide) 전극 형성방법은 ITO 박막 자체의 전기 광학적 특성 뿐 아니라 ITO를 전극으로 하는 청색 발광 다이오드(파장 469nm)의 전기 광학적 특성 및 신뢰성에도 큰 영향을 미침을 확인하였다. 세 가지 ITO 전극 형성 방법 즉 electron beam evaporation법과 sputtering법, 그리고 electron beam evaporation법으로 먼저 증착한 뒤에 sputtering법으로 증착한 hybrid법 등을 사용하여 청색 발광 다이오드를 제작한 다음에 ITO 박막의 특성과 aging에 따른 발광 다이오드의 전기 광학적 특성 변화를 고찰하였다. 그 결과, ITO 전극을 sputtering 또는 electron beam evaporation 방법으로 형성한 발광 다이오드는 각각 sputtering damage의 문제와 전기저항이 증가하는 문제점을 안고 있음을 발견하였다. 그리고 이 문제점들을 hybrid 방법으로 해결하였다.

• 한국지반환경공학회 논문집
• /
• 제23권4호
• /
• pp.11-20
• /
• 2022

불포화층의 수리특성을 획득하기 위하여 증발법, 압력판추출시험, 냉각거울법으로 함수특성시험을 수행하고 비교하였다. 증발법과 냉각거울법은 신시험법으로서 신속하고 정확하게 불포화토의 함수특성곡선을 획득할 수 있다. 증발법과 압력판추출시험에서는 100kPa 범위의 모관흡수력까지 함수특성을 획득하여 비교하였으며, 이로부터 증발법 시험결과를 검증할 수 있었다. 매우 높은 수준의 모관흡수력에서는 냉각거울법을 통하여 함수특성을 측정하고 이로부터 전체적인 함수특성곡선의 양상을 파악할 수 있었다. 모든 함수특성시험을 통하여 얻은 함수특성의 대표곡선을 구하고 각 시험법의 적용성을 비교하였다. 증발법 및 냉각거울법 시험을 병행하면 전체 모관흡수력 범위에서 함수특성곡선을 합리적으로 획득할 수 있었다.

• 한국환경과학회지
• /
• 제10권5호
• /
• pp.323-327
• /
• 2001

A new method is developed to estimate the evaporation of water from a surface with high accuracy and resolution. The principle of new method is to detect a weight change of buoyant weight according to a change in water level of Class A Pan mesured by the use of a strain-gauge load cell. Field test of evaporation recording new instrument was carried out at Suwon for 10 days July 1999. It is possible in field observation to measure hourly evaporation amount by newly developed evaporation recording instrument in Class A Pan against strong solar radiation. Present study provide a possibility of domestic high accuracy instrument development below than 0.1mm water level measurement accuracy. If there is low humidity and high wind speed conditions which is possible to evaporate from water surface during night time. And it needs continuous study to understand between meteorological elements and latent heat effect at ground level by field observation study using high accuracy evaporation recording instrument.

• Journal of Radiation Protection and Research
• /
• 제13권2호
• /
• pp.52-56
• /
• 1988

수중의 방사능을 측정하기 위한 전처리과정으로서 이온교환농축법과 증발건조법을 서로 비교하였다. 시료를 증발건조법으로 처리하였을때 방사성물질의 손실율은 이온교환농축법에 비해 20% 정도 많았다. 또, 1리터의 시료를 처리하는 데 소요된 증발시간은 $70^{\circ}C$에서 증발시킨 경우 약20시간이었으나 이온교환농축법으로 같은 양의 시료를 처리하는데 소요된 시간은 약6시간이었다. 따라서 이온교환농축법이 증발건조법에 비해 효과적이며 특히 수중의 저준위 방사성물질 측정에 적합한 것으로 나타났다.

• International Journal of Automotive Technology
• /
• 제7권2호
• /
• pp.121-128
• /
• 2006

The interaction between adherent molecules and gas molecules was modeled in the molecular scale and simulated by the molecular dynamics method in order to understand evaporation and removal processes of adherent molecules on metallic surface using high temperature gas flow. Methanol molecules were chosen as adherent molecules to investigate effects of adhesion quantity and gas molecular collisions because the industrial oil has too complex structures of fatty acid. Effects of adherent quantity, gas temperature, surface temperature and adhesion strength for the evaporation rate of adherent molecules and the molecular removal mechanism were investigated and discussed in the present study. Evaporation and removal rates of adherent molecules from metallic surface calculated by the molecular dynamics method showed the similar dependence on the surface temperature shown in the experimental results.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.1564-1567
• /
• 2009

Cu(In,Ga)$Se_2$ (CIGS) thin films were formed using CIGS bulk by electron-beam evaporation method with an evaporation current from 20 mA to 90 mA. The experimental results showed that the chemical compositions and the properties of CIGS films varied with the different evaporation current. The Cu-rich CIGS film was deposited successfully with a band gap of 1.20 eV when the evaporation current was 90 mA.