• 대한기계학회논문집A
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• 제40권9호
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• pp.767-773
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• 2016

산 및 알칼리 용액 속에 침지한 SiC 세라믹의 기계적 특성은 와이블 통계로 해석하였다. 시험편은 1373K에서 열처리를 행하였다. SiC의 부식은 KSL1607 방법에 의한 산 및 알칼리 용액 속에서 수행하였다. 부식된 균열치유재의 굽힘 강도는 부식되지 않은 균열치유재의 굽힘강도보다 산 및 알칼리 용액 속에서 각각 47% 및 70% 감소하였다. SiC 세라믹의 부식은 산 용액 속에서보다 알칼리 용액 속에서 더 빨랐다. 척도 파라미터 및 형상 파라미터는 모재와 부식재에서 평가하였다. 산 및 알칼리 용액에서 부식된 모재의 형상 파라미터는 산용액에서 크게 나타났다. 그러나 열처리재는 산용액에서 크게, 알칼리 용액에서 작게 나타났다. 모재 및 열처리재의 척도 파라미터는 산 및 알칼리 용액에서 모두 작게 나타났다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.561-562
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• 2006

The purpose of this study was to investigate the root cause of adhesion of silica and ceria particles during Poly-Si, TEOS, and SiN CMP process, respectively. The zeta-potentials of abrasive particles and wafers were observed negative surface charges in the alkaline solutions. SAC and STI patterned wafers have intermediate values of their composition surface's zeta potentials. The theoretical interaction force and adhesion force of silica and ceria particle were calculated in solution with acidic, neutral and alkaline pH. A stronger attractive force was calculated for silica and ceria particles on wafers in acidic solutions than in alkaline solutions. The theoretical interaction forces of the SAC and STI patterned wafers have intermediate values of their constitution wafer's values. The adhesion forces is observed lower values in alkaline solutions than in acidic solutions. And the ceria particle has lower adhesion than that of the silica particle.

• 대한화학회지
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• 제10권4호
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• pp.161-165
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• 1966

The critical concentrations of ${\alpha}$-amino capric acid for micelle formation have been determined by the surface tension measurements in both acidic and alkaline solutions, and also by the dye titration using Rhodamine B in alkaline solutions. The critical micelle concentrations obtained by the two methods show the good agreements within experimental errors. Since ${\alpha}$-amino acid is an ampholyte, it may aggregate to form the micelles in both more acidic and basic media than its isoelectric point. It is found that the basic media are rather preferable for the micelle formation than the acidic media. The effect of gegen ions upon the critical concentration for micelle formation in alkaline media is similar to that expected from the salt effect on the CMC (Critical Micelle Concentration).

• 한국표면공학회지
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• 제28권1호
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• pp.55-63
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• 1995

Alkaline solutions such as $NH_4$OH, choline and TMAH (($CH_3$)$_4$NOH) have been introduced in semiconductor wet processing of silicon wafers to control ionic and particulate impurities following etching in acidic solutions. These chemicals usually mixed with hydrogen peroxide and/or surfactants to control the etch rate of silicon. The highest etch rate was observed in $NH_4$OH solutions at a pH in alkaline solutions. It indicates that the etch rate depends on the content of $OH^{-}$ as well as cations of alkaline solutions. STM/AFM techniques were used to characterize the effect of alkaline solutions on silicon surface roughness. In SC1 (mixture of $NH_4$OH : $H_2$$O_2$ : $H_2$O) solutions, the reduction of the ammonium hydroxide proportion from 1 to 0.1 decreased the surface roughness ($R_{rms}$) from 6.4 to $0.8\AA$. The addition of $H_2$$O_2$ and surfactants to choline and TMAH reduced the values of $R_{p-v}$ and $R_{rms}$ significantly. $H_2$$_O2$ and surfactants added in alkaline solutions passivate bare silicon surfaces by the oxidation and adsorption, respectively. The passivation of surfaces in alkaline solutions resulted in lower etch rate of silicon thereby provided smoother surfaces.s.ces.s.

• 약학회지
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• 제31권4호
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• pp.236-251
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• 1987

The chemistry, antimicrobial properties, organic soil resistance, toxicity, corrosivity and chemical stability of stabilized alkaline 2%, glutaraldehyde solution(SGS) are discussed. SGS retains the maximum antimicrobial activity of alkaline glutaraldehyde solutions and the chemical stability here to fore observed only with acidic glutaraldehyde solutions. These improvements, along with the inherent resistance of glutaradehyde to neutralization by organic soil, allow SGS to be continuously used for 14 days in situations of high dilution, or 28 days in situations of low dilution.

• Applied Biological Chemistry
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• 제19권1호
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• pp.51-56
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• 1976

$SO_2$ 수용액의 화학적 변화를 in vitro system에서 조사하였다. 농도가 다른 수용액이 20시간 후에 비슷한 Eh값에 도달하였으며 산성용액에서는 Eh값이 그 이상 증가하지 않았다. Eh값은 알카리성용액에서 보다는 중성용액에서 크게 증가하였고 암흑에서 보다는 광조건하에서 다소 높은 경향을 나타냈다. 유리상태의 $SO_2$함량은 아황산염의 농도가 증가하거나, 광에 노출한 경우, 또는 pH가 높은 때에 크게 감소하였다. 발생기수소는 고농도의 $SO_2$나 산성용액에서 보다는 중성 혹은 알카리성 용액에서 더욱 많이 생성되었다.

• Journal of Electrochemical Science and Technology
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• 제13권2호
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• pp.213-226
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• 2022

In the present study, the corrosion behavior of aluminum Al-7075 tempered (T-6 condition) alloy was evaluated by immersion testing and electrochemical testing in 1.75% and 3.5% NaCl environment at acidic, neutral and basic pH. The data obtained by both immersion tests and electrochemical corrosion tests (potentiodynamic polarization and electrochemical impedance spectroscopy tests) present that the corrosion rate of the alloy specimens is minimum for the pH=7 condition of the solution due to the formation of dense and well adherent thin protective oxide layer. Whereas the solutions with acidic and alkaline pH cause shift in the corrosion behavior of aluminum alloy to more active domains aggravated by the constant flux of acidic and alkaline ions (Cl^- and OH^-) in the media which anodically dissolve the Al matrix in comparison to precipitated intermetallic phases (cathodic in nature) formed due to T6 treatment. Consequently, the pitting behavior of the alloy, as observed by cyclic polarization tests, shifts to more active regions when pH of the solutions changes from neutral to alkaline environment due to localized dissolution of the matrix in alkaline environment that ingress by diffusion through the pores in the oxide film. Microscopic analysis also strengthens the results obtained by immersion corrosion testing and electrochemical corrosion testing as the study examines the corrosion behavior of this alloy under a systematic evaluation in marine environment.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.391-407
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• 2023

This article provides a survey of wet (aqueous) methods for recovery, separation, and purification of uranium from fission products in carbonate solutions during the reprocessing of spent nuclear fuel and methods for removal of radionuclides from alkaline radioactive waste. The main methods such as selective direct precipitation, ion exchange, and solvent extraction are considered. These methods were compared and evaluated for reprocessing of spent nuclear fuel in carbonate media according to novel alternative non-acidic methods and for treatment processes of alkaline radioactive waste.

• 한국표면공학회지
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• 제40권3호
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• pp.138-143
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• 2007

The effects of texturing and anti-reflection coating on the reflection properties of multi-crystalline silicon solar cell have been investigated. The chemical solutions of alkaline and acidic etching solutions were used for texturing at the surface of multi-crystalline Si wafer. Experiments were performed with various temperature and time conditions in order to determine the optimized etching condition. Alkaline etching solution was found inadequate to the texturing of multi-crystalline Si due to its high reflectance of about 25%. The reflectance of Si wafer texturing with acidic etching solution showed a very low reflectance about 10%, which was attributed to the formation of homogeneous. Also, deposition of ITO anti-reflection coating reduced the reflectance of multi-crystalline si etched with acidic solution($HF+HNO_3$) to 2.6%.

• 한국염색가공학회지
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• 제8권1호
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• pp.34-42
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• 1996

This Study was made to investigate alkaline dyeing systems for a new dyeing applicable polyester fibers. Disperse dyes for dyeing of polyester fibers were C.I. Red 60, Blue 56 and Yellow 54 as three primary colors of E type which used widely on the scene. Dyeing properties of dispers dyes on the polyester fibers are discussed according to variation of pH values for application of alkaline dyeing method compared with to ordinary acidic dyebath. Alkaline pH of the dyebath was controlled to pH 9 and 10.5 with buffer solutions using each hydrochloride and disodiumtetraborate, disodiumtetraborate and sodium hydroxide to promote the reproducibility of dyeing. Dyeing properties of dispers dyes on the polyester fibers by alkaline dyeing method compared with to ordinary acidic dyebath were discussed by estimation of color, wash-fastness, bleeding and migration of dyed polyester fabric.