• Bulletin of the Korean Chemical Society
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• 제28권10호
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• pp.1751-1755
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• 2007

The interaction of ammonium hydroxide (NH4OH) with zircaloy-4 (Zry-4) was investigated using X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) methods. In order to study the surface chemistry of NH4OH/Zry-4 system, the binding energies of N1s, O1s and Zr3d electrons were monitored. The N1s peak intensity was remarkably increased by following cycles of Ar+ sputtering of NH4OH dosed Zry-4 surface at room temperature. Because the nitrogen stayed under the subsurface region was diffused out onto the Zry-4 surface after oxygen concentration was decreased. These could be occurred after the surface oxygen was diffused into the bulk or desorbed out from the surface until Ar+ fluence was 6.0 × 1016 Ar+/cm2 then the surface was relatively atomic deficient state. The O1s peak intensity was decreased by stepwise Ar+ sputtering. After many cycles of Ar+ sputtering, the peak intensities of Zr3d peaks did not change much but the shape of the peak clearly did change. This implies that the oxidation state of zirconium was changed during stepwise Ar+ sputtering of NH4OH/Zry-4. The Zr3d peak intensity of zirconium nitride (ZrNx) increased as the intensity of N1s (from zirconium nitride) increased but the Zr3d peak intensity of zirconium oxide (ZrOx) decreased due to the depopulation of the oxygen species on the surface region. We also observed that the peak intensity of Zr4+ was nearly same after Ar+ sputtering processes but the peak intensity of metallic zirconium increased compared to that of before the sputtering process was performed.

• 분석과학
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• 제6권2호
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• pp.217-223
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• 1993

저항가열식 진공중착기를 이용하여 실온(ambient temp.)과 $250^{\circ}C$에서 알루미나 기판 위에 Au/Cr, Au/Ni/Cr 및 Au/Pd/Cr 박막을 제조하였으며, 공기 중에서 $300^{\circ}C$, $450^{\circ}C$, $600^{\circ}C$의 온도로 각각 1시간 동안 열처리하였다. Au, Ni(또는 Pd) 및 Cr 박막의 두께는 각각 $1000{\AA}$, $300{\AA}$, 및 $50{\AA}$이었다. 박막 제조시 기판의 온도와 박막 제조 후 열처리 온도는 각 층의 상호확산으로 인하여 박막의 면저항값에 영향을 주었다. Auger depth profile 분석결과, Au/Cr 시스템에서는 기판의 온도는 $250^{\circ}C$로 하여 박막을 제조할 때 이미 Cr은 Au 표면으로 확산되었으며, 열처리 후에는 Au의 분포도만 변화하였다. Au/Ni/Cr과 Au/Pd/Cr 시스템의 경우 Ni와 Pd 모두 확산현상이 발견되었으며, 특히 Ni(약 45 at.%)는 Au 박막 표면으로 확산되어 산화되었다.

• 한국축산시설환경학회지
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• 제20권1호
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• pp.1-8
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• 2014

The study on design criteria of solid-liquid separator for dairy farms was done by testing various screens, presses, and RPMs of screw auger with remodeled screw-press type pig-manure separator. The moisture content of separated solid increase from 68.3% to 74.2% as auger rotating speed increased from 9.8 to 29.2 RPM at 34.8 kPa of pressure and 1.0 mm of slit wedge wire screen condition. The moisture contents of separated solid were 72~77%, work efficiencies were 16~18 kg/min at 1.0 mm of slit wedge wire screen. The efficiency was higher than one at 0.5 mm of slit wedge wire screen, which was used to separate for pig manure. The best work efficiency was 18 kg/min at 42.5 kPa, 1.0 mm slit screen. The separated solid moisture content was 75% at this condition.

• Journal of Magnetics
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• 제7권2호
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• pp.45-50
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• 2002

A magnetic field annealing is firstly used for nanostructured Sm-Co/Co films, prepared by magnetron sputtering method. The effects of magnetic field annealing on single-layered Sm-Co films are different from those on multi-layered Sm-Co/Co films. A detailed analysis of microstructures and magnetic properties is made by means of HRTEM, Auger electron spectroscopy, XRD and Physical Property Measurement System (PPMS). From magnetic properties and microstructure analysis, it was confirmed that these differences originate from the effects of magnetic field annealing on crystallization behavior of the films. The relationship between magnetic properties and microstructures explains a different demagnetization process of single-layered and multilayered films. For the single-layered Sm-Co films, magnetic-field-annealing makes the main phases change from $CaCu_5/ to Zn_2Th_{17}$ structure, resulting in a decrease of coercivity. The results show that the magnetic-field-annealing is useful to improve the properties of nanostructured Sm-Co(30 nm)/Co(10 nm) films, which ascribe to improving the pinning effectiveness in coercivity mechanism and decreasing the magnetostatic interaction of films. A very high coercivity about 0.7 T was obtained from nanoscaled multi-layered Sm-Co(30 nm)-/Co(10 nm) films.

• 한국지반신소재학회논문집
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• 제21권4호
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• pp.41-53
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• 2022

본 연구에서는 도시철도에 인접하여 암반굴착공사를 실시할 때 발생하는 지반진동이 도시철도 구조물에 미치는 영향을 수치 해석을 통하여 검증하였다. 암반굴착공사는 발파공사와 굴착기계공사의 두 경우에 대하여 실시하였다. 발파공사는 굴착부지가 넓은 경우에 정밀진동제어방법과 소규모진동제어방법에 대한 해석을 실시하고 실무에서 기준처럼 사용하고 있는 발파진동 영향권을 검증하였다. 이 발파진동 영향권에서 제시하는 발파 이격거리는 범위가 매우 커서 범위 값 중 최소치에 발파점이 위치할 때 진동한계치를 넘어갈 수 있다. 굴착기계공사는 천공공사를 위한 어스오거와 착암공사를 위한 브레이커에 의한 지반진동이 도시철도 구조물에 미치는 영향을 검증하였다. 시험시공을 통하여 어스오거와 브레이커의 지반진동을 측정하고 보정을 거쳐서 수치해석을 위한 입력하중을 산출하였다. 수치해석은 터널구조, 개착식 박스구조, 고가교량구조에 대하여 실시하였다. 터널구조의 해석에서 결과는 어스오거는 현장 추정치와 비슷하나 브레이커에서는 현장에서 얻어지는 추정치보다 작다. 발파공 사이의 충전매질을 통한 충격파 전파 효과를 수치적으로 시뮬레이션하고 검증하였다. 개착식 박스구조에서는 굴착공과 박스사이의 매립토가 지반진동을 증폭시키는 형상이 발생하며 진동파가 박스구조물에 도달하면 일정한 값으로 수렴한다. 고가교량의 경우에는 진동하중이 상대적으로 작은 어스오거 지반진동은 파일기초에 도달하면서 작아지는데, 상대적으로 크고 주기적인 브레이커 지반진동은 교량 상부구조에 추가적인 지반 진동하중으로 작용함을 볼 수 있다.

• 한국진공학회지
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• 제5권3호
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• pp.223-228
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• 1996

$SiO_2$ insulator layers on InSb have been prepared by remote PECVD system a low temperature below $200^{\circ}C$. The effects of deposition pressure, temperature, and gas flow ratio on the physical and electrical characteristics of the $SiO_2$ were studied. The InSb MIS device using $SiO_2$ was fabricated and measured its current-voltage and capacitance-voltage characteritance-voltage charateristics at 77K. The films evaluated Auger electron spectroscopy showed that composition atoms were distributed uniformaly throughout the oxide film and the outdiffusion of substrate atoms into the oxide were few. The leakage current density of the MIS device was about 6.26nA/$\textrm{cm}^2$ at 0.75MV/cm , and the breakdown voltage was about 1MV/cm. The interface-stage density at mid-bandgap extracted from 1MHz C-V measurement was $54\times 10^{11}\textrm{cm}^2-2V^{-1}$.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.301-304
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• 2007

다결정 태양전지의 원료인 폴리실리콘을 생산하는 방법 중 하나인 지멘스 방법에서 사용되는 실리콘 코어로드를 금속 계열의 코어로드로 대체하기 위한 연구를 진행하였다. 본 연구에서는 실리콘 코어로드의 대체물질 후보로서 고융점 금속인 텅스텐, 탄탈륨, 몰리브덴을 선택하였고, co-sputtering system을 이용하여 다성분계의 박막을 실리콘 기판에 증착시켜 $800^{cdot}C$에서 $1000^{cdot}C$의 고온에서 열처리 후 박막의 형상변화 및 확산정도를 관찰하였다. 열처리 온도에 따른 박막의 형상 및 확산 정도를 관찰하기 위하여 Scanning electron microscopy (SEM), X-ray diffractometer(XRD), transmission electron microscopy(TEM), auger electron spectroscopy(AES)가 사용되었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.483-483
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• 2012

Recently, nonthermal bioplasma has been attracted by researchers due to their potentials to modulate cellular functions resulting in changes of biomolecular electron band structures as well as cell morphologies. We have investigated the secondary electron emission characteristics from the surface of the erythrocyte, i.e., red blood cell (RBC) with and without the nonthermal bioplasma treatment in morphological and biomolecular aspects. The morphologies have been controlled by osmotic pressure and biomolecular structures were changed by well known reactive oxygen species. Ion-induced secondary electron emission coefficient have been measured by using gamma-focused ion beam (${\gamma}$-FIB) system, based on the quantum mechanical Auger neutralization theory. Our result suggests that the nonthermal bioplasma treatment on biological cells could result in change of the secondary electron emission coefficient characterizing the biomolecular valence band electron energy structures caused by the cell morphologies as well as its surface charge distributions.

• 한국진공학회지
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• 제4권3호
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• pp.270-274
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• 1995

The growth structure of Fe on CU(001) was studied by scanning tunneling microscope. An analysis of size distribution of Fe islands on Cu(001) surface was made to determine whether Fe atoms mix with substrate Cu. The size distribution deviates from the standard scaling behavior, indicating that atomic density of Fe decreases with coverage up to 1 ML. The growth can be characterized by layer-by-layer scheme from 1 ML to 5 ML. This result agrees well with previously studied, Auger spectroscopy and RHEED result.

• Corrosion Science and Technology
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• 제4권3호
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• pp.89-94
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• 2005

This paper presents the results of a study that was undertaken to optimize the ratio of the components of a new multi-component inhibitor blend composed of orthophosphate/ phosphonates/ acrylate copolymer/ isothiazolone. The effects of newly developed inhibitor on carbon steel dissolution in synthetic cooling water were studied through weight loss tests, electrochemical tests, scale tests, and micro-organism tests. The obtained results were compared to blank (uninhibited specimen) and showed that developed inhibitor revealed very good corrosion, scale, and micro-organism inhibition simultaneously. All measurements indicated that the efficiency of the blended mixture exceeded 90 %. The inhibitive effects arose from formation of protective films which might contain calcium phosphate, calcium phosphonate, and iron oxide. The nature of protective films formed on the carbon steel was studied by scanning electron microscopy (SEM) and auger electron spe ctroscopy (AES). Inhibitor used in this study appeared to have better performance for scale inhibition due to their superior crystal modification effect and excellent calcium carbonate scale inhibition properties. The effect of inhibitor on microorganisms was evaluated through minimum inhibitory concentration (MIC) test. All kinds of micro-organisms used in this study were inhibited under 78ppm concentration of inhibitor.