• Bulletin of the Korean Chemical Society
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• 제17권2호
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• pp.192-198
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• 1996

We present a theoretical formulation of diffusion process on solid surface based on multidimensional transition state theory (TST). Surface diffusion of single adatom results from hopping processes on corrugated potential surface and is affected by surface vibrations of surface atoms. The rate of rare events such as hopping between lattice sites can be calculated by transition state theory. In order to include the interactions of the adatom with surface vibrations, it is assumed that the coordinates of adatom are coupled to the bath of harmonic oscillators whose frequencies are those of surface phonon modes. When nearest neighbor surface atoms are considered, we can construct Hamiltonians which contain terms for interactions of adatom with surface vibrations for the well minimum and the saddle point configurations, respectively. The escape rate constants, thus the surface diffusion parameters, are obtained by normal mode analysis of the force constant matrix based on the Hamiltonian. The analysis is applied to the diffusion coefficients of W, Ir, Pt and Ta atoms on the bcc(110) plane of W in the zero-coverage limit. The results of the calculations are encouraging considering the limitations of the model considered in the study.

• 한국산림과학회지
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• 제90권4호
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• pp.450-457
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• 2001

산림의 수원함양기능 지표인 표층토양에서의 조공극율(粗孔隙率)(pF2.7) 에 영향하는 입지환경인자를 밝히기 위해 1994년 3월부터 10월까지 전국의 활엽수림 표본조사구를 대상으로 업지, 토양, 임분환경인자 등 총 15인자에 대하여 spss/pc+를 이용하여 상관 분석하였다. 표층토양에서의 조공극률에 영향을 미치는 수고, 하층식생 피복도, 토양의 유기물함량비 3개 인자가 유의한 정(正)의 상관관계를, 표층토양의 견밀도가 1% 수준에서 유의한 부(負)의 상관관계를 나타내었다. Stepwise를 이용한 다중회귀분석결과 표층토양에서의 조공극률에 영향하는 인자는 표층토양의 견밀도, 토양의 유기물함량비 2개 인자이었다. 활엽수림의 수원함양기능 증진을 위한 시업은 표층토양의 조공극 발달이 촉진되도록 하층식생 피복도가 30%에서 80%를 유지하도록 실시해야 할 것으로 판단된다.

• 한국농공학회논문집
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• 제62권4호
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• pp.87-97
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• 2020

The livestock infections had been happened seasonally, but they have gradually changed to be irrelevant to seasons and have an aspect to rapidly spread after outbreak. Especially in Korea, proactive disinfection measures are very important because the livestock farms are located densely so high as to accelerate the spread of disease between farms. livestock disease outbreaks like HPAI and FMD occurred with high probability due to vehicles visiting the farms, this study is to evaluate the efficiency of livestock vehicle disinfection systems by investigating the disinfectant coverage according to the type of vehicle disinfection system and the type of vehicle quantitatively. In field experiments, water-sensitive papers (WSPs) were attached to 21 locations on the surface of four vehicles (sedan, SUV, truck, and feed transport), respectively, and exposed to disinfectants while the vehicle was sprayed in two vehicle disinfection systems (tunnel type and simplified type). The WSPs were scanned and image-processed to calculate the disinfectant coverage. The results showed that the tunnel-type vehicle disinfection system had a better disinfection performance with an average coverage of 90.27% for all vehicles compared to 32.62% of the simplified type system. The problem of the simplified system was a wide coefficient of variation (1.05-1.31) of the disinfectant coverage between 21 locations indicating a need for further improvement of nozzle location and arrangement.

• 한국산학기술학회논문지
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• 제21권12호
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• pp.798-806
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• 2020

치면열구전색법은 건전한 구치부의 교합면의 좁고 깊은 소와나 열구를 전색 하여 교합면에 발생되는 치아우식증을 예방하기 위한 술식이다. 치면열구전색의 급여화 기준 확대 및 국가구강보건사업 결정에 필요한 기초자료를 제공하고자 본 연구를 시행하였다. 본 연구는 국민영양조사 원시자료 제 5기, 6기, 7기 자료를 토대로 만 6~18세 이하 소아청소년을 총 4,366명을 대상으로 치면열구전색 수혜량과 수혜률을 조사하였다. 2012년 치면열구전색 수혜률에서는 나이, 동. 읍면, 월 평균 가구소득에서 차이가 있었고. 일반적 특성이 수혜에 미치는 요인에서는 2014년 월평균 가구소득 2017년 나이, 월평균 가구소득에서 수혜률 차이가 나타났다(P<0.05). 연도별 일반적 특성이 수혜에 미치는 요인에서 2012년에서 동. 읍면, 월 평균 가구소득 2014년은 월 평균 가구소득, 2017년은 나이와 월 평균 가구소득이 영향을 미치는 요인으로 나타났다(P<0.05). 치아우식증에 효과적인 치면열구전색의 수혜량과 수혜률 증가를 위해서는 지속적인 사업의 홍보와, 본인부담금 감소 및 대상 치아 및 연령 확대, 소외지역 및 취약계층에 대한 지원 확대 방안에 대해서 다각적으로 논의해야 할 것으로 요구되어진다.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2006년도 춘계학술발표회 논문집
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• pp.281-286
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• 2006

In this study, acquired time series Landsat TM/ETM+ image to extract land surface temperature for wide-area region and executed geometric correction and radiometric correction. And extracted land surface temperature using NASA Model, and I achieved the first correction by perform land coverage category for study region and applies characteristic emission rate. Land surface temperature that acquire by the first correction analyzed correlation with Meteorological Administration's temperature data by regression analysis, and established correction formula. And I wished to improve accuracy of land surface temperature extraction using satellite image by second correcting deviations between two datas using establishing correction formula. As a result, land surface temperature that acquire by 1,2th correction could correct in mean deviation of about ${\pm}3.0^{\circ}C$ with Meteorological Administration data. Also, could acquire land surface temperature about study region by relative high accuracy by applying to other Landsat image for re-verification of study result.

• 통합자연과학논문집
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• 제4권3호
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• pp.182-186
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• 2011

Chemical modification of porous silicon surface has been investigated to have different physical surface properties. Porous silicon modified with dodecyl functionality exhibits hydrophobic feature, however the oxidation of porous silicon to modify with hydroxyl group displays hydrophilic properties. Surface characterization for both dodecyl and hydroxyl derivatized porous silicon was investigated by FT-IR spectroscopy. To determine the surface coverage, the amine functionalized surface was reduced by dithiothreitol (DTT) and the released 2-thiopyridone was quantified by UV/vis spectroscopy.

• Bulletin of the Korean Chemical Society
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• 제28권3호
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• pp.413-416
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• 2007

The adsorption and surface reactions of NO on a VO/V(110) surface have been investigated using X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure, and temperature programmed desorption (TPD) technique. NO is molecularly adsorbed on VO/V(110) at 80 K. As the surface coverage of NO increases, the NO dimer is formed on the surface at 80 K. Both NO and (NO)2 are adsorbed on the surface with the N-O bond perpendicular to the surface. (NO)2 decomposes at ~100 K and the reaction product is desorbed as N2O. Decomposition of NO takes place when the surface temperature is higher than 273 K.

• 대한기계학회논문집B
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• 제21권1호
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• pp.165-173
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• 1997

The present study investigates heat/mass transfer for flow through perforated plates for application to combustor wall and turbine blade film cooling. The experiments are conducted for hole length to diameter ratios of 0.68 to 1.5, for hole pitch-to-diameter ratios of 1.5 and 3.0, for gap distance between two parallel perforated plates of 1 to 3 hole diameters, and for Reynolds numbers of 60 to 13, 700. Local heat/mass transfer coefficients near and inside the cooling holes are obtained using a naphthalene sublimation technique. Detailed knowledge of the local transfer coefficients is essential to analyze thermal stress in turbine components. The results indicate that the heat/mass transfer coefficients inside the hole surface vary significantly due to flow separation and reattachment. The transfer coefficient near the reattachment point is about four and half times that for a fully developed circular tube flow. The heat/mass transfer coefficient on the leeward surface has the same order as that on the windward surface because of a strong recirculation flow between neighboring jets from the array of holes. For flow through two perforated plate layers, the transfer coefficients on the target surface (windward surface of the second wall) affected by the gap spacing are approximately three to four times higher than that with a single layer.

• 한국태양에너지학회 논문집
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• 제29권6호
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• pp.81-87
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• 2009

The purpose of this study is to evaluate of the outdoor thermal environment by building scale and block type as variable factors. In this study, 18 cases of office in central business district that have different condition are compared about their surface temperature, HIP(Heat Island Potential), and MRT(Mean Radiant Temperature). They are simulated with 3-dimension numerical simulation software named Hoyano-model. The output results contain visualized distribution chart and numerical data. The results of evaluation are as follows. (1)The surface temperature of the building becomes higher as building coverage ratio is higher but floor area ratio is lower. In same conditions, unified block type is maximum $3.2^{\circ}C$ higher than divided block type. (2)HIP shows different daily pattern as block type. During daytime, divided block type is much higher than unified block type but after sunset, it is changed. (3)MRT shows different distribution pattern as sunlight moves expecially at noon. (4)As the results of this study, cases that have high floor area ratio condition show lower surface temperature by tendency to stay low indoor temperature in office building and big rate of windows on building surface.

• 한국진공학회지
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• 제2권4호
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• pp.404-409
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• 1993

Adorption of nitric oxide on the Pt(III) surface sputtered by Ar-ion has been studied using thermal desorption spectroscopy and Auger electron spectroscopy. Ar-ion sputtering creates a precursor state of ($NO\beta$ stage) adsorbe dat defect sites. The precursor state is characterized by the terminal bent species . At low coverge mos 샐 adsorbed NO dissociates . And as increasing the coverage, the fraction of dissociation remains about 80%.