• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.209-214
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• 2003

Numerical simulations are performed at atmospheric pressure in order to understand the effect of additives on flame speed, flame temperature, the radical concentration, the NOx formation in freely propagating $CH_4/O_2/N_2$ flames. The additives used are carbon dioxide and hydrogen chloride which have a combination of physical and chemical behavior on hydrocarbon flame. In the flame established with the same mole of methane and additive, $CO_2$ addition significantly contributes toward the reduction of flame speed and flame temperature by the physical effect, whereas addition of HCl mainly does by the chemical effect. The impact of HCl addition on the decrease of the radical concentration is about 1.6-1.8 times as large as $CO_2$ addition. Hydrogen chloride addition is higher on the reduction of EINO than $CO_2$ addition because of the chemical effect of HCl.

• 전자공학회논문지 IE
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• 제46권3호
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• pp.1-5
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• 2009

고전력, 고온에서 사용되는 소자에서 RuO2는 다른 전극 물질에 비해 많은 장점을 가지고 있으며, 특히 GaN를 이용하는 소자의 전극물질로서 매우 우수한 특성을 갖음을 확인할 수 있었다. RuO2을 이용한 GaN 소자의 제작은 새로운 전기화학 금속증착법을 통하여 금속배선을 형성하였으며, 과염소산(HClO4)용액을 수용액 사용하였다. RuO2의 두께는 인가전압과 시간에 의존하며, 두께를 조절함으로서 정류성 및 비정류성 소자의 전극으로의 사용 가능성을 확인할 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
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• pp.62-65
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• 2002

Transparent conducting aluminum-doped Zinc oxide films (ZnO:Al) were prepared by rf magnetron sputtering on glass (Coming 1737) substrate as a variation of the deposition condition. After deposition, the smooth ZnO:Al films were etched in diluted HCl (0.5%) to examine the electrical and surface morphology properties as a variation of the time. The most important deposition condition of surface-textured ZnO films by chemical etching is the processing pressure and the substrate temperature. In low pressures (0.9mTorr) and high substrate temperatures $({\leq}300^{\circ}C)$, the surface morphology of films exhibits a more dense and compact film structure with effective light-trapping to apply the silicon thin film solar cells.

• 한국재료학회지
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• 제16권1호
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• pp.63-67
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• 2006

The characteristics of the wet-etching of ZnO thin films were investigated using hydrochloric and phosphoric acid solutions as etchants. The etch rate of ZnO films, using highly diluted hydrochloric acid solutions at a concentration of 0.25% in deionized water, was determined to be about 120 nm/min, and linearly increased with increasing the acid concentration, resulting in $1.17{\mu}m/min$ when a 2% HCl solution was used. The surface of ZnO etched by an HCl solution, observed by scanning electron microscopy, showed a rough morphology with a high density of hexagonal pyramids or cones with sidewall angles of about ${\sim}45^{\circ}C$. Moreover, the sidewall angles of the masked area were similar to those of the pyramids on the surface. In comparison, the surface of ZnO etched by a phosphoric acid had a smooth surface morphology. The origin of this difference is from the very initial stage of etching, indicating that the etch-mechanism is different for each solution. Furthermore, when $H_3PO_4$ was added to the HCl aqueous solution, the morphology of the etched surface was greatly enhanced and the sidewall angle was also increased to about $65^{\circ}C$.

• 공업화학
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• 제7권6호
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• pp.1105-1114
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• 1996

${\alpha}-PbO_2/IrO_2-TiO_2/Ti$지지체상에 sodium lauryl sulfate 및 $TiO_2$분말을 첨가한 질산납 전해액에서 전착한 ${\beta}-PbO_2$층의 특성 및 성능을 XRD, SEM, cyclic voltammograms, 매크로전해를 이용하여 검토하였다. XRD분석결과 sodium lauryl sulfate 및 $TiO_2$분말의 존재하에 ${\alpha}-PbO_2/IrO_2-TiO_2/Ti$ 지지체 위에 전착한 ${\beta}-PbO_2$층은 순수한 ${\beta}-PbO_2$층과 마찬가지로 정방정계구조를 나타냈다. SEM결과 sodium lauryl sulfate는 전착층의 결정입자크기를 작게 하는 경향을 보여준다. sodium lauryl sulfate 및 $TiO_2$분말의 존재하에 전착한 ${\beta}-PbO_2$전극은 KOH 및 $HClO_4$지지전해질에서 양극산화에 대한 산소과전압과 내구성을 크게 향상시켰다. 티타늄마드래스에 전착시킨 ${\beta}-PbO_2$전극을 이용하여 과염소산용액으로부터 오존 발생에 대한 전극성능과 내구성을 검토하였다. $HClO_4$지지전해질에 sodium lauryl sulfate와 $TiO_2$분말을 첨가하여 ${\alpha}-PbO_2/IrO_2-TiO_2/Ti$ 마드래스상에 전착한 ${\beta}-PbO_2$전극이 가장 높은 전류효율과 내구성을 가짐을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2203-2207
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• 2009

Chemical equilbria of nickel chloride in HCl solution at $25\;{^{\circ}C}$ were analyzed by considering chemical equilibria, mass and charge balance equations. The activity coefficients of solutes were calculated by using Bromley equation. The necessary thermodynamic properties, such as the equilibrium constant for the formation of Ni$Cl^+$ at zero ionic strength and interaction parameter, were evaluated by applying Bromley equation to the stability constant data reported in the literature. It was found that most nickel exists as $Ni^{2+}$ in HCl solution up to 5 molality HCl. The pH values of Ni$Cl_2-HCl-H_2O$ system at $25\;{^{\circ}C}$ calculated in this study agreed well with the pH values measured by employing pH meter.

• Membrane and Water Treatment
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• 제12권2호
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• pp.75-82
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• 2021

This study aimed to prepare a W/O nonionic microemulsion system(MEs) consisting of OP-4[polyoxyethylene(4) nonylphenol], OP-7[polyoxyethylene(7) nonylphenol], 1-hexanol, D2EHPA, kerosene and HCl solution and applied to the extraction of La(III) from chloride aqueous solution within the polysulfone hollow fiber contactor (HFC),laboratory-scale experiments were carried out to investigate the recovery of La(III) using as-prepared microemulsion from the simulation wastewater containing La(III),Al(III) and Fe(III). The right weight ratio(Rs) of OP-4 to OP-7 was firstly confirmed through determination of the solubilization capacity of HCl solution(W0,HCl) in microemulsion, the effect of several factors such as the HCl concentration, temperature and effective extraction time on the extraction efficiency of La(III) was discussed. Results showed that the acceptable Rs was 4:6 to prepare the W/O MEs. The extraction yield of La(III) increased with the increasing of HCl concentration, temperature and effective extraction time and reaches to 97.3% while using five-stage modules. The recovery yield of La(III) from simulation La-bearing wastewater was 90.6%.

• 한국토양비료학회지
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• 제47권6호
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• pp.464-472
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• 2014

The Codex Committee of Contaminants in Food (CCCF) has been discussing a new standard for arsenic (As) in rice since 2010 and a code of practice for the prevention and reduction of As contamination in rice since 2013. Therefore, our current studies focus on setting a maximum level of As in rice and paddy soil by considering bioavailability in the remediation of As contaminated soils. This study aimed to select an appropriate single chemical extractant for evaluating the mobility of As in paddy soil and the bioavailability of As to rice. Nine different extractants, such as deionized water, 0.01 M $Ca(NO_3)_2$, 0.1 M HCl, 0.2 M $C_6H_8O_7$, 0.43 M $HNO_3$, 0.43 M $CH_3COOH$, 0.5 M $KH_2PO_4$, 1 M HCl, and 1 M $NH_4NO_3$ were used in this study. Total As content in soil was also determined after aqua regia digestion. The As extractability of the was in the order of: Aqua regia > 1 M HCl > 0.5 M $KH_2PO_4$ > 0.43 M $HNO_3$ > 0.2 M $C_6H_8O_7$ > 0.1 M HCl > 0.43 M $CH_3COOH$ > deionized water > 1 M $NH_4NO_3$ > 0.01 M $Ca(NO_3)_2$. Correlation between soil extractants and As content in rice was in the order of : deionized water > 0.01 M $Ca(NO_3)_2$ > 0.43 M $CH_3COOH$ > 0.1 M HCl > 0.5 M $KH_2PO_4$ > 1 M $NH_4NO_3$ > 0.2 M $C_6H_8O_7$ > 0.43 M $HNO_3$ > 1M HCl > Aqua regia. BCF (bioconcentration factor) according to extractants was in the order of : 0.01M $Ca(NO_3)_2$ > 1 M $NH_4NO_3$ > deionized water > 0.43 M $CH_3COOH$ > 0.1 M HCl > 0.43 M $HNO_3$ > 0.2 M $C_6H_8O_7$ > 0.5 M $KH_2PO_4$ > 1 M HCl > Aqua regia. Therefore, 0.01 M $Ca(NO_3)_2$ ($r=0.78^{**}$) was proven to have the greatest potential for predicting As bioavailability in soil with higher correlation between As in rice and the extractant.

• 한국세라믹학회지
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• 제30권6호
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• pp.485-491
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• 1993

Porous glass in the ZrO2.SiO2 system containning up to 30mol% zirconia were prepared by the sol-gel method from metal alkoxides and their pore characteristics with reaction parameters were investigated. The gels were made by hydrolyzing and condensation of the mixed metla alkoxides and were converted into the porous glass by heating up to $700^{\circ}C$. As a results, the mean pore radius became larger with increasing contents of HCl, H2O and hydrolysis temperature, and an alcohol with a large molecular weight for making the porous glass. In the case of 20ZrO2.80SiO2 porous glass with heated at $700^{\circ}C$, HCl and H2O content was 0.3mol and 4mol, the specific surface area was 284$m^2$/g, average mean pore radius was about 19.4$\AA$, porosity was 22.55% and pore characteristics depended on heating temperature.

• 한국세라믹학회지
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• 제47권6호
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• pp.613-617
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• 2010

Ferro-Nickel slag is one of the by-products in Ferro-Nickel manufacturing process. The slag is composed of $SiO_2$, MgO, $Fe_2O_3$ and others. But the slag has been buried at landfill despite having valuable elements. This study tried to extract Mg ion and fabricate Mg compound from ferro-nickel slag using hydrochloric acid solution. Mg ion was extracted with Si, Fe and other ions in HCl solution. So reprocess was needed for gaining high purity Mg ion. It was thought that Si ion or $SiO_2$ precipitated in HCl solution and removed from solution in filtering process. Fe ion converted into $Fe(OH)_3$ after reacted with $NH_4OH$ and precipitated in HCl solution. After these process, the filtrate was composed of high purity Mg ion. $MgCl_2{\cdot}NH_4Cl{\cdot}6H_2O$ was obtained through drying of filtrate and this product was changed into MgO by burning process ($600^{\circ}C$-30 min). That is, 1st material or solution for manufacturing 2nd product was fabricated using acid dissolution method and other treatments.