• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.268-277
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• 2004

process (ACP), electrochemical properties of high heat-generating alkali and alkali earth oxides in molten salt were measured and the behavior of those elements were analyzed. The reduction potentials of Cs, Sr, and Ba in a molten LiCl-$Li_2O$ system were more cathodic than that of Li and closely located one another. Thus, it is expected that the alkali and alkali earth would not hinder the reaction mechanism which is via lithium reduction. Alkali and alkali earth metals are likely to recycle into molten salt when the process is operated beyond metal reduction potentials and the effect of electric current on the mass transport is also determined by measuring the metal concentrations in the molten salt phase at different current conditions.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.427-434
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• 2012

Waterborne polyurethane dispersions (PUD) were synthesized from poly (carbonate diol), isophrone diisocyanate and dimethylol propionic acid at different NCO/OH molar ratios. Subsequently, the PUD was mixed with different types of alkali metal salts ($LiClO_4$, $NaClO_4$, and $KClO_4$) to prepare antistatic waterborne polyurethane coating solutions. Effects of the types and amounts of alkali metal salts were investigated on the surface resistances of the resulting coating films. The surface resistances of coating films were decreased with increasing the amounts of alkali metal salts added in the PUD. The coating films prepared with the same amount of alkali metal salts showed increased ionic conductivity with the order of $LiClO_4$ > $NaClO_4$ > $KClO_4$. Also, the surface resistances of coating films were increased with increasing the molar ratios of NCO/OH in the PUD.

• Proceedings of the Korean Printing Society Conference
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• 2001.06a
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• pp.45-45
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• 2001

자료의 보존에 있어서 종이의 열화로 인해 자료의 분석, 열화메커니즘의 해석, 종이의 보존이란 측면 하에서의 관심이 서서히 집중되고 있는 실정이며, 그 중요성도 크게 대두되고 있는 실정이다. 산성지를 중성화하는 화학적시스템, 즉, 탈산성화처리는 알카리계금속(Ca, Mg, Zn, Na)과 유기용매, 수용성용매를 이용하여 이들 약품을 종이내에 침투시켜 중성화(pH 6-8) 함으로써 종이의 주성분인 cellulose를 보다 안정화시키는 방법으로 산을 중화하여 보존성을 향상시킬 수 있는 것이다. 즉, 탈산처리란 화학적으로 종이속에 생기는 산 또는 산을 발생하는 물질을 알칼리물질로 중화하는 것이다. 또한 중화후 알칼리 물질이 종이에 잔류하면 장래에 내부적으로 발생하는 산이나 외부(대기중의 오염물질 등) 로부터 침입하는 산도 중화하여 보존성을 향상시킬 수가 있다. 따라서, 본 연구는 산성초지법에 의해 제조된 용지들의 열화특성과 알카리 토금속을 처리한 후에 알카리도를 상승시킨 용지의 열화특성을 물리·화학적 변화를 통하여 종이의 보존성을 비교 검토·규명함으로써 문(도)서의 보존체계를 마련하고자 하며, 보존과 관련된 기초자료를 얻고자 실시하였다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1994.05a
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• pp.9-14
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• 1994

알카리금속염 (K$_2$CO$_3$, $K_2$SO$_4$). 알카리 토금속염 (Ba(NO$_3$)$_2$), 철족금속염(Ni(NO$_3$)$_2$, FeSO$_4$) 으로 이루어진 여러가지 혼합물들이 반응온도 700~85$0^{\circ}C$ 하의 촤-수증기 가스화반응에서 나타내는 촉매활성을 열천칭 반응기를 사용하여 측정하였다. 비촉매 가스화반응에서 초기반응성은 수증기 분압에 비례하였다. 촉매 가스화반응에서 단일염 촉매의 경우 $K_2$CO$_3$ 가 가장 큰 활성을 나타내었으며, 다른 염들은 낮은 활성을 보였다. 혼합염의 경우 $K_2$SO$_4$에 철족염을 부가함에 따라 반응속도가 향상되었으며, $K_2$SO$_4$+Ni(NO$_3$)$_2$가 가장 큰 촉매활성을 나타내었다. $K_2$SO$_4$와 Ni(NO$_3$)$_2$ 의 촉매 활성은 담지량에 따라 증가하며, 석탄의 등급에 따라 감소하였다. $K_2$SO$_4$와 Ni(NO$_3$)$_2$의 혼합비는 같은 몰비로 혼합하였을때 가장 큰 활성을 나타내었다.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.956-961
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• 2000

This paper describes the design of a small size Alkali Metal Thermal to Electric Converter (AMTEC) which employs a capillary structure for recirculating sodium working fluid. The cycle is based on the simple and small capillary type ${\beta}"$ -alumina and wick tube element. The proposed cell consists of the 37 conversion elements with capillary tube of $50{\mu}m$ in diameter and the sealed cylindrical vessel of 22mm in outer diameter. Results on the cycle analysis of sodium flow and heat transfer in the cell showed that the expected power output was 4.65W and the conversion efficiency was 19% for the source temperature of 900K.

• The tire
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• s.7
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• pp.25-29
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• 1967

이미 Srereo Rubber 에 관해서 많은 연구보문이 발표된 바 있으나 대부분이 중합법, 성질 및 가공법등을 품목별 또는 부분적으로 해설한 것이기 때문에 본장에서는 미국제를 중심으로 각종 Stereo Rubber 의 중합촉매, 구조특성 및 가공특성등을 함께 묶어서 논술한 것을 소개코자 미국 Ohio주 Akron시 수강한 "Stereo Rubber"란 제목을 간추린 것이다.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.48.1-48.1
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• 2010

Mono-crystalline silicon solar cell is fabricated by using alkali metals. These alkali metal, used in wet etching process, must be removed for the high efficiency solar cell. As wet etching process has been adapted due to its low cost. But lots of alkali metals like potassium remains on the silicon surface and acts as impurities. To remove these alkali metals many of cleaning process have to be applied when solar cell manufacturing process. In terms of alkali metal removal, modified etchant solution is required for concise cleaning process. In this paper ethylenediamine was used and proposed for the substituion of postassium hydroxide.

• Applied Chemistry for Engineering
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• v.3 no.2
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• pp.266-272
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• 1992

Azacrownoalkyl phenylphosphinic acids were synthesized and their competitive solvent extraction characteristics from water to chloroform layer were investigated. Phosphinic acids were synthesized in good yields by one step reaction of phenylphosphinate, aldehyde, and monoazacrown ether and then basic hydrolysis of the resulting phosphinate dsters. These complexing agents revealed a wide effective pH range in extraction of alkali metal ions from water to the organic phase and total metal ion loading at pH 11 was about 75%. The selectivity of the cation extraction was determined mainly by the cavity size of the azacrown ethers, showing $Na^+$ >> $K^+$ > $Rb^+$ > $Li^+$ > $Cs^+$ for the alkyl phenylphosphinic acid ${\underline{2}}$, containing monoaza-15-crown-5 and $K^+$ >> $Rb^+$ > $Na^+$ > $Cs^+$ > $Li^+$ for the alkyl phenylphosphinic acid, ${\underline{3}}$, containing monoaza-18-crown-6 moiety. Applicable pH range of these azacrown ether phosphinic acids in solvent extraction of alkali metal cations was wider than a crownether carboxylic acid with similar selectivity, showing considerable amount of metal ion loading in slightly acidic or neutral media.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11a
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• pp.285-285
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• 2005

• Journal of the Korean Chemical Society
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• v.27 no.2
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• pp.127-132
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• 1983

The catalytic activity of ZSM-5 catalyst for the disproportionation of toluene is dependent on the type of cation exchanged, the degree of ion-exchange and the reaction temperature. The activity increases in the order of alkaline-, alkali earth-, hydrogen, and rare-earth-exchanged ZSM-5 and decreases with increasing degree of cation exchange. Among the ion-exchanged ZSM-5 catalyst, only Cs-ZSM-5 shows predominant selectivity for p-xylene. The selectivity increases with increasing degree of $Cs^+$-exchange and decreasing reaction temperature. This phenomenon is interpreted in terms of shape selectivity arising from the partial blocking of channel intersections by large cesium ions.