• 한국세라믹학회지
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• 제16권3호
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• pp.155-163
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• 1979

This study was to explore the characteristics of 6 mole% CaO stabilized $ZrO_2$ prepared by wet chemical methods. The results of the experiments were as follows: 1. The powder calcined at 1000$^{\circ}$-110$0^{\circ}C$ was partly agglomerated. The morphology of agglomerate was spherical of 0.5-1$\mu{m}$ in size for Hot Petroleum Drying Method, chain-like of 1-2$\mu{m}$ for Freeze Drying Method, and irreqular of 2-3$\mu{m}$ for Coprecipitation Method. 2. Optimum calcining conditions for powder prepared by wet chemical methods were found: 110$0^{\circ}C$, 2h in air for Hot Petroleum Drying Method and Freeze Drying Method, and 100$0^{\circ}C$, 2h in air for Coprecipitation Method. 3. When specimen was calcined at 1000$^{\circ}$-110$0^{\circ}C$ in air for 2h and then sintered at 1$600^{\circ}C$ in air for 4h, the specimens prepared by wet chemical methods showed a high sintered density (94% of theoretical density) and a low open porosity (<0.8%); however, the sintered density of the specimen prepared by Oxide Wet Mixing Method was 90%. 4. The amount of cubic phase of sintered body prepared by wet chemical methods was observed to be higher than the one prepared by Oxide Wet Mixing Method. 5. It was found that Hot petroleum Drying Method, Freeze Drying Method and Coprecipitation Method were nearly the same in respect of the results of stabilization grade and sintered density of CaO-stabilized $ZrO_2$.

• 한국연초학회지
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• 제20권1호
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• pp.19-25
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• 1998

The bulk curing experiment to the improve the quality of flue-cured leaves were carried out to evaluate relationship between cyclic curing and conventional curing method. We studied the effect of the cyclic change of wet bulb temperature at the yellowing stage of flue curing on chemical properties of cured leaves. The wet bulb temperature was automatically controlled between preset high($38^{\circ}C$) and low point ($35^{\circ}C$) everyone hour cyclically during 12 hours after starting luring. As a result, the acceleration of the increase in the chemical properties of cured leaves were observed. As to the chemical properties, there was decreased in citric acid, increased in malic acid of the nonvolatile organic acids and all higher fatty acids content of leaves cured by this method compared with in that of conventional curing method, while a major chemical compounds in relation to aromatic essence of cigarette smoke in essential oil components of lured leaves was mostly higher in this method than those of conventional ones, and it was evaluated that there was decreased in CO, TPM, Tar, and $CO_2$ content of the cigarette smoke comparing to the conventional luring method.

• 펄프종이기술
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• 제42권3호
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• pp.7-13
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• 2010

KOptimization and control of wet-end process provide a key solution to improve paper quality and production efficiency at the same time. Wet-end of paper machine is to determine three important influencing factors of papermaking i.e., retention, drainage and formation. Good formation of paper could be made at the cost of deteriorated retention or drainage. In the same manner increase of retention aid could cause the bad formation of paper. It is very important to find a proper retention chemical which may satisfy one of three factors without the sacrifice of other two. Laboratory scale analyzing or screening chemical additives of wet-end was reported in this study based on RDA sheet molding. Different from the conventional test method, simultaneous consideration of three important wet-end properties could be made by RDA and consequently more reliable prediction of actual paper machine wet-end could be expected.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.667-667
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• 2013

Optimizing morphology of the front surface with three dimensional structures (3D) in solar cell is essential element for not only effectivelight harvesting but also carrier collection and separation without the cost burden in process. We designed a three-dimensionally ordered front surface with wet chemical etching. Wet chemical etching is a proper way to have three dimensional structures. The method efficiently transmits the incident light at the front surface to a Si absorber and has competitive price in manufacturing when comparing with reactive ion etching (RIE) to have three dimensional structures. This indicates that optimized front surface with three dimensional structures by wet chemical etching will bring effective light management in solar cells.

• 대한화학회지
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• 제14권1호
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• pp.49-50
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• 1970

A wet oxidation method of oxalic acid standard used in radiocarbon dating is described, and error due to possible carbon isotope fractionation during the oxidation is estimated.

• Bulletin of the Korean Chemical Society
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• 제30권12호
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• pp.3095-3097
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• 2009

• 한국표면공학회지
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• 제50권6호
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• pp.523-530
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• 2017

In this study, we developed the h-BN interphase for ceramic matrix composites (CMCs) through a wet chemical coating method, which has excellent price competitiveness and is a simple process as a departure from the existing high cost chemical vapor deposition method. The optimum condition for nitriding an h-BN interphase using boric acid and urea as precursors were derived, and the h-BN interphase coating through a wet method on a carbon preform of 2.5 D was conducted to apply the optimum conditions to the CMCs. In order to control the coating property via the wet coating method, four parameters were investigated such as dipping time of the specimen in the precursor solution, the ratio of boric acid and urea in the precursor, the concentration of solution where the precursor was dissolved, and the cycle of dipping and dry process. The CMCs was fabricated through polymer impregnation and pyrolysis (PIP) processes and a three-point flexural strength test was conducted to verify the role of the coated h-BN interphase.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3280-3288
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• 2014

Alkoxyalcohols are used as solvents or preservatives in various consumer products such as wet wipes. The metabolites of alkoxyalcohols are known to be chronically toxic and carcinogenic to animals. Thus, an analytical method is needed to monitor alkoxyalcohols in wet wipes. The aim of this study was to develop a simultaneous analytical method for 14 alkoxyalcohols using headspace gas chromatography coupled with mass spectrometry to analyze the wet wipes. This method was developed by comparing with various headspace extraction parameters. The linear calibration curves were obtained for the method ($r^2$ > 0.995). The limit of detection of alkoxyalcohols ranged from 2 to $200ng\;mL^{-1}$. The precision of the determinative method was less than 18.20% coefficient of variation both intra and inter days. The accuracy of the method ranged from 82.86% to 119.83%. (2-Methoxymethylethoxy)propanol, 2-phenoxyethanol, and 1-phenoxy-2-propanol were mainly detected in wet wipes.

• 한국분말재료학회지
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• 제13권4호
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• pp.278-284
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• 2006

Spherical Ag powder was prepared in the system of $AgNO_3\;and\;NaBH_4$ by wet chemical reduction method. The size of Ag powder was increased as the reaction temperature and the concentration of reducing agent was decreased in the constant concentration of dispersion agent. Optimum conditions of producing Ag powder having $1.39{\mu}m$ of D50 was 1M of $AgNO_3$, 0.5M of $NaBH_4$, 1.5g of Gelatine in the room temperature.

• 한국분말재료학회지
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• 제21권2호
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• pp.93-96
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• 2014

Cobalt coated tungsten carbide-cobalt composite powder has been prepared through wet chemical reduction method. The cobalt sulfate solution was converted to the cobalt chloride then the cobalt hydroxide. The tungsten carbide powders were added in to the cobalt hydroxide, the cobalt hydroxide was reduced and coated over tungsten carbide powder using hypo-phosphorous acid. Both the cobalt and the tungsten carbide phase peaks were evident in the tungsten carbide-cobalt composite powder by X-ray diffraction. The average particle size measured via scanning electron microscope, particle size analysis was around 380 nm and the thickness of coated cobalt was determined to be 30~40 nm by transmission electron microscopy.