• 한국진공학회지
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• 제9권1호
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• pp.30-35
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• 2000

Indium-Tin Oxide (ITO) thin films were deposited on the commercial glass substrate by rf-magnetron sputtering. The ITO films with the thickness of 2,000~2,400 $\AA$ were prepared by changing the oxygen partial pressures of 2, 3, and 5%, as well as by changing the substrate temperature of $300^{\circ}C$ and $500^{\circ}C$. spectrophotometer, XRD, SEM, AFM, 4-point probe and Hall effect system were employed to characterize the ITO films. The optimum deposition conditions were the substrate temperature of $500^{\circ}C$ and oxygen partial pressure of 2-3%. At theses conditions, the ITO film showed the transmittance of 91%, the resistivity of $5.4\times10^{-3}\Omega$cm, the carrier concentration of $1.0\times10^{19}\textrm{cm}^{-3}$, and the carrier mobility of 150$\textrm{cm}^2$/Vsec. In XRD spectra, the (222) and (400) $In_2O_3$ planes were dominant under the optimum deposition conditions When the substrate was cleaned only by the method of ultrasonic cleaning without both pre-annealing and chemical treatment of the substrate, the ITO film exhibited the transmittance of 86%, the carrier concentration of $5.4\times10^{19}\textrm{cm}^{-3}$ and the mobility of 24$\textrm{cm}^2$/Vsec.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권5호
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• pp.39-45
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• 2013

Many researchers have studied the effectiveness of ultrasound in chemical and environmental engineering fields including material synthesis, pollutant removal, cleaning, extraction, and disinfection. Acoustic cavitation induced by ultrasound irradiation in aqueous phase can cause various sonophysical and sonochemical reactions without any chemicals. However most of the previous studies focused only on the relationships between ultrasonic conditions and the results of sonochemical reactions in lab-scale sonoreactors. As a results of this, only a few studies have been devoted to design and optimization of industrial scale sonoreactors. In this study, the effect of the distance between two opposite transducer modules on sonochemical reactions was investigated in single and dual irradiation systems (334 kHz) for four distances including 50, 100, 150, and 200 mm using KI dosimetry. It was found that the dual irradiation systems provided higher performance in terms of the zeroth reaction coefficient and the cavitation yield compared to the single irradiation systems. The sonochemiluminescence (SCL) images for the visualization of the cavitation field showed that cavitation active zone was larger and sonochemical reaction intensity was much higher in the dual irradiation system than in the single irradiation system.

• 대한소아치과학회지
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• 제48권4호
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• pp.484-489
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• 2021

소아 및 청소년의 치면의 흑색 착색은 통증이나 심각한 병적 상태를 유발하지 않지만 심미적인 단점으로 인해 환자가 사회적으로 위축되게 한다. 흑색 착색은 주기적인 전문가 치면세균막 관리 및 스케일링을 통해 쉽게 제거되나 수개월 이내에 재발하는 문제가 있다. 50%로 희석한 에센셜 오일 함유 가글액을 하루 2회씩 사용하는 것은 흑색 착색이 제거된 뒤에 재발하는 것을 예방할 수 있으며 이를 통해 처치의 빈도를 줄이면서 심미성을 개선할 수 있다.

• Journal of Advanced Marine Engineering and Technology
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• 제24권6호
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• pp.61-69
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• 2000

Indium-Tin Oxide (ITO) films were prepared on the commercial glass substrate by the Magnetron Sputtering method. The target was a 90wt.% $In_2O_3$-10wt.% $SnO_2$with 99.99% purity. The ITO films deposited by changing the partial pressure of oxygen gas ($O_2$/(Ar+$O_2$)) of 2, 3 and 5% as well as by changing the substrate temperature of $300^{\circ}C$ or $500^{\circ}C$. The influence of substrate pre-annealing and pre-cleaning on the quality of ITO film were examined, in which the substrate temperature was $500^{\circ}C$ and oxygen partial pressure was 3%. The characteristics of films were examined by the 4-point probe, Hall effect measurement system, SEM, AFM, Spectrophotometer, and X-ray diffraction. The optimum ITO films have been obtained when the substrate temperature is $500^{\circ}C$ and oxygen partial pressure is 3%. At optimum condition, the film showed transmittance of 81%, sheet resistivity of $226\Omegatextrm{cm}^2$, resistivity($\rho$) of $5.4\times10^{-3}\Omega$cm, carrier concentration of $1.0\times10^{19}cm^{-3}$, and carrier mobility of $150textrm{cm}^2$Vsec. From XRD spectrum, c(222) plane was dominant in the case of substrate temperature at $300^{\circ}C$, without regarding to oxygen partial pressure. However, in the case of substrate temperature at $500^{\circ}C$, c(400) plane was grown together with c(222) plane, only for oxygen partial pressure of 2 and 3%. In both case of chemical and ultrasonic cleaning without pre-annealing the substrate, it showed much almost same sheet resistivity, resistivity($\rho$), transmittance, carrier concentration, and carrier mobility. In case of $500^{\circ}C$/60min pre-annealing before ITO film deposited, both transimittance and carrier mobility are better than no pre-annealing, because pre-annealing is supposed to remove alkari ions diffusion from substrate. ITO film deposited on the Corning 0080 sybstrate showed a little bit better sheet resistivity, resistivity($\rho$), transimittance, carrier concentration than the film deposited on commercial glass. But no differences between Corning substrate and pre-annealed commercial glass substrate are found.

• 구강회복응용과학지
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• 제32권4호
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• pp.263-273
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• 2016

지대주의 재료와 표면에 따라 연조직반응이 다르고 임플란트 주위염의 원인이 될 수 있다. 티타늄과 지르코니아는 우수한 생체적합성을 가져 안정적인 연조직반응을 보이고 금합금은 표면상태에 따라 연조직반응이 다르게 나타난다. 같은 재료라도 표면특성에 따라 연조직반응이 영향을 받는다. 표면거칠기 증가는 박테리아 부착을 유발하므로 연조직과 접촉하는 부분은 평활한 표면을 가져야 한다. 추가적인 표면처리를 통해 박테리아의 부착은 증가시키지 않으면서 세포반응을 촉진시킬 수 있다. 지대주의 형태 및 반복착탈도 연조직반응에 영향을 줄 수 있다. 초음파 세척과 아르곤 플라즈마 처리는 비교적 효과적으로 맞춤형 지대주의 잔류 미세입자를 제거할 수 있는 방법이다.

• 박물관보존과학
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• 제27권
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• pp.103-124
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• 2022

부여 장하리 삼층석탑의 연구는 석탑 부재에 대한 물성 평가를 수행하여 석탑의 현재 상태를 객관적으로 파악하고 석조문화재의 훼손에 적합한 보존처리 방안을 수행하기 위해 실시하였다. 평균 전암대자율 값은 3.71(10^-3 SI unit)로 나타났고, 석탑 부재는 최소 4종류의 화강암으로 분류되며, 동일한 기원을 가지지 않은 것으로 판단된다. 초음파 속도는 평균 1,519m/s로 풍화 지수를 환산한 결과 평균 4등급으로 나타났고, 열화상 측정을 통해 시멘트 부재와 원 부재의 열적 구배를 확인하였으며, 부분적으로 원암과 비슷한 신석으로 교체되어야 할 것으로 사료된다. 과학적 조사를 바탕으로 풍화 훼손 지도를 작성하고, 선행연구를 통해 적합한 보존처리 방안을 수립하였다. 생물피해와 변색이 심하여 증류수와 브러쉬를 이용한 습식세척을 실시하여 표면의 오염물을 제거하였으며, 박리가 되는 부분을 에폭시 수지와 동질의 석분을 현장에서 제작하여 혼합한 후 보강하였다.

• 한국치위생학회지
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• 제7권3호
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• pp.213-230
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• 2007

The purpose of this study was to examine the state of infection control provided to members of Korean Dental Hygienists Association. The subjects in this study were dental hygienists who attended a symposium on July 1. 2006. after a survey was conducted, the answer sheets from 489 participants were analyzed, and the findings of the study were as follows: 1. Possession of disinfection room was being(72.7%), and person of infection control was zero(52.9%). Number of sterilizer was one(62.2%). 2. As a repetition choice, type of sterilizer was autoclave(97.9%), UV sterilizer(67.4%) and EO gas sterilizer(21.4%). As a repetition choice, infection materials was ethanol(84.1%). 3. Water tube of unit and chair was using of sterilized water(42.9%). Sterilizing of compressed air was no(69.0%). 4. Re-using of disposal was not using(62.5%), re-using disposal was suction tip(28.2%)(repetition choice) 5. In sterilization of instruments, hand-piece was every using time(28.4%), and reamer-file, bur, mirror, pincette, explorer, hand scaler and ultrasonic scaler were high in every using time. 6. Individual protection was high of using, cleaning of hands before treatment was every treatment(87.0%). Type of soap was liquid type in dental clinic(48.2%), infection soap in dental hospital(41.2%) and solid soap in public health center(50.6%). Answered that they need regular oral health education, and 82.9% respondents answered that they need oral health technicians in school. And 87.8% respondents needed individual oral health education for the benefit of better oral health.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.74-74
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• 2018

Ti-6Al-4V alloys have been widely used as orthopedic materials because of their excellent corrosion resistance and mechanical properties. However, it does not bind directly to the bone, so it requires a surface modification. This problem can be solved by nanotube and micropore formation. Plasma electrolytic oxidation (PEO) treatment for micropore, which combines high-voltage spark and electrochemical oxidation, is a new way of forming a ceramic coating on light metals such as titanium and its alloys. This method has excellent reproducibility and can easily control the shape and size of the Ti alloy. In this study, formation of bioactive surface by PEO-treatment after $2^{nd}$ ATO technique of Ti-6Al-4V alloy was invesgated by various instrument. Nanotube oxide surface structure was formed on the surface by anodic oxidation treatment in 0.8 wt.% NaF and 1M $H_3PO_4$ electrolytes. After nanotube formation, nanotube layer was removed by ultrasonic cleaning. PEO-treatment was carried out at 280V for 3 minutes in the electrolytic solution containing the bioactive substance (Mg, Zn, Mn, Sr, and Si). The surface of Ti-6Al-4V alloy was observed by field emission scanning electron microscopy (FE-SEM, S-4800 Hitachi, Japan). An energy dispersive X-ray spectrometer (EDS, Inca program, Oxford, UK) was used to analyze the spectra of physiologically active Si, Mn, Mg, Zn, and Sr ions. The PEO film formed on the Ti-6Al-4V alloy surface was characterized using an X-ray diffractometer (TF-XRD, X'pert Philips, Netherlands). It is confirmed that bioactive ions play an essential role in the normal bone growth and metabolism of the human skeletal tissues.

• 한국주조공학회지
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• 제41권2호
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• pp.139-143
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• 2021

타이타늄 합금 중 페로-타이타늄은 철강 업계에서 철강과 스테인리스강을 생산하는데 사용되는 주요 첨가물이다. 본 연구에서는 고품질의 페로-타이타늄 합금을 주조하기 위해 경제적인 면을 고려한 저비용 타이타늄 스크랩을 활용하고자 하였다. 먼저 재활용 타이타늄 스크랩의 표면에 형성되어 있는 절삭유 및 불순물을 제거하기 위한 최적의 전처리 공정을 연구하였다. 일반적인 세척 방법인 산이나 유기용제는 세척이 용이하나 환경적으로 문제가 되므로 친환경적인 방법을 고안하여 적용하고자 하였다. 또한, 타이타늄 스크랩을 활용하여 고품질의 페로-타이타늄 잉곳을 제조하고 성분 분석을 통해 불순물과 특성을 상용 소재 규격과 비교 분석하였다.

• 한국산업융합학회 논문집
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• 제26권4_2호
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• pp.561-570
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• 2023

This study was to evaluate the effect of different rinsing times and methods on the accuracy of temporary prostheses fabricated by 3D printing method. Sixty temporary prostheses were fabricated with LCD types of 3D printer(Halot-Sky, Creality, Shenzhen, China) and divided into six groups (n = 10) based on rinsing times and methods. All specimens were rinsed with 99% isopropanol alcohol for 5 and 10 min using three methods-hand washed, ultrasonic cleaning, and automated washing. All specimens were polymerized for 3 minutes under the same conditions. The marginal and internal gaps of specimens were examined using a replica technique. The light-body silicone thickness was measured at 6 reference points(Absolute marginal discrepancy, Marginal, Chamfer, Axial, Angle, and Occlusal gap). All measurements were performed by a stereomicroscope. Reference point images were taken at 100× magnification and then measured using an image analysis program. Statistical analysis was performed using Two-way ANOVA, One-way ANOVA, and the Kruskal-Wallis test (p = .05). The marginal and internal gaps were statistically different according to the rinsing methods and rinsing times(p < .001). In the rinsing time, the temporary prosthesis rinsed for 5 minutes group showed higher accuracy than 10 minutes group. In the rinsing method, the hand washing group showed higher accuracy than the automated washing group.