• 보존과학연구
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• 통권14호
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• pp.35-44
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• 1993

The way of prevention for the continuous corrosion progress in iron antiquities after excavation and conservation treatment have been studied. The corrosion occuring have been found the oxidation of ferrous ions in the presence of chloride. The consideration to control the activity of chloride is important of controling relative humidity for the stable environment of the storage. One of the method that keeps archeological iron antiquities recommend the storage of special vinyl film(poly-vinyl alcohol film) with silica gel to control the relative humidity. Although this method is not permanent, it's very well efficiency of economy and convenience at present.

• 한국세라믹학회지
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• 제25권6호
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• pp.585-592
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• 1988

Aluminum sec-butoxide was synthesized from aluminum foil and alcohol. The characteristics of the alumina powder prepared from the synthesized alkoxide by the Yoldas method were studied. As a result of measuring the synthesized aluminum sec-butoxide by GC, the purity of the synthesized alkoxide was 98.7% on the basis of commercial alkoxide and the yield was 78.5%. A127-MASNMR analysis shows that powders dried at 9$0^{\circ}C$ and $\alpha$-Al2O3 have 6-cordinated structure and ${\gamma}$-Al2O3 has 4-coordinated structure. The characteristics of alumina powder prepared from the synthisized alkoxide showed the same characteristics with the alumina powder prepared from the commercial alkoxide.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1459-1461
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• 2009

In this study, we prepared the multi-refraction film thin by ink-jet technique with sol-gel precursor. The precursors were prepared by using some transition metal alk-oxide and the tetraethylorthosilicate (TEOS) mixed separately with n-Butyl Alcohol and PVB (Poly(vinyl butyral)).The structure and morphology of the resulting films were investigated by atomic force microscope (AFM). It is shown that the shape of the pattern of the films would affect the refraction proportion.

• Archives of Pharmacal Research
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• 제19권6호
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• pp.502-506
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• 1996

Protein X is one of the subunits of pyruvate dehydrogenase complex. The biological role of this protein has not been fully elucidated, mainly because of the difficulty in its dissociation from the tightly bound dihydrolipoamide acetyltransferase-protein X subcomplex. We have found that the detachment of protein X from acetyltransferase subunit can be easily accomplished by the cycles of freezing and thawing proces. Several lines of evidence including sodium dodecyl sulfate-polyacrylamide gel electrophoresis, N-terminal amino acid sequence analysis and acetylation with $[2^{14}C]$ pyruvate confirmed that the purified protein is protein X. The purified intact form of protein X was acetylated by $[2^{14}C]$ pyruvate in the presence of py-ruvate dehydrogenase subunit.The acetylation efficiency of this protein was lower than that of acetyltransferase and was not affected by the presence of acetyltransferase.

• 분석과학
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• 제17권4호
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• pp.295-301
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• 2004

In this study, static and dynamic solvent extractions are compared for more efficient extraction of polychlorinated dibenzofurans (PCDFs) from fly ash. Static solvent extraction rather than dynamic extraction showed a higher recovery of PCDFs, which was adsorbed strongly with fly ash. The effects of parameters, such as temperature, toluene-isopropyl alcohol mixture, static and dynamic time flow rate, and solvent volume on the extraction were investigated and the variations in average recoveries of PCDFs were explained. In both extractions, temperature was an effective parameter because the higher temperature gave the higher recoveries. In dynamic solvent extraction, dynamic time was more effective than flow rate and solvent volume for the extraction of PCDFs from fly ash. Multi-layer column chromatography on neutral and acidic silica gel with n-hexane was used for cleaning up the extracts. The quantification of the PCDFs extracted was performed using HPLC-UV.

• 한국산림과학회지
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• 제68권1호
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• pp.32-36
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• 1985

소나무의 acid phosphatase (ACP), alcohol dehydrogenase (ADH)와 catalase (CAT) 동위효소(同位酵素) 유전양식(遺傳樣式)을 구명(究明)하기 위하여 배유조직(胚乳組織)을 수평식 감자전분 전기영동법에 의하여 분석(分析)하였다. ACT 동위효소(同位酵素)는 최소한 3~4개의 지역(地域)으로 분리(分離)되었으나 분리가 잘된 ACP-A 지역(地域)의 동위효소(同位酵素)만이 분석(分析)되었다. ACP-A 지역(地域)에서 관찰된 5개(A1-A5)의 동위효소(同位酵素) 표현형(表現型)들은 공히 Mendel의 분리비(分離比)를 보여 이들이 각각 ACP-A 유전자좌(遺傳子座)에 존재(存在)하는 5개의 대립유전자(對立遺傳子)에 의해 지배받고 있음을 알 수 있었다. 2개의 ADH 지역(地域)이 (ADH-A와 ADH-B) 분리(分離)되었으나, 양극(陽極)으로의 이동(移動)속도가 빠른 ADH-A 지역(地域)에서는 분석(分析)에 사용된 재료(材料)에서 변이(變異)가 발견(發見)되지 않았다. ADH-B 지역(地域)에서는 3개의 동위효소(同位酵素) 표현형(表現型) (B1-B3)들이 관찰되었고 이들이 공히 1:1의 분리비를 보여 ADH-B 유전자좌(遺傳子座)에 존재하는 3개의 대립유전자(對立遺傳子)에 의해 지배됨이 추정되었다. 수개의 band로 구성된 5개의 동위효소(同位酵素) 표현형(表現型)이 CAT에서 관찰되었으며, 이형접합성(異型接合性)인 모수(母樹)에서 이들 표현형간(表現型間)의 분리(分離)가 1:1 분리비(分離比)로부터 편차(偏差)를 보이지 않았으므로, 소나무에 있어서 CAT 동위효소(同位酵素)는 5개의 대립유전자(對立遺傳子)가 존재(存在)하는 하나의 유전자좌(遺傳子座)에 의해 지배되는 것으로 추정하였다.

• Restorative Dentistry and Endodontics
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• 제31권2호
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• pp.79-85
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• 2006

생활치 미백제와 알콜 전처리 과정이 상아질 접착에 미치는 영향을 평가하고자 발거치 55개의 치관부 협측 상아질면에서 $Opalescence^{(R)}$(Ultradent사 미국)로 미백처리 후 즉시 $One-step^{(R)}$ 상아질 접착제(Bisco사, 미국)를 전 처치한 $Z-250^{(R)}$ 복합레진(3M-ESPE사, 미국) 접착군, 미백처리 2주후 레진 접착군, 미백처리 후 70% 에탄올 처리군, 그리고 미백처리하지 않은 대조군으로 나누어 실험한 다음 전단접착강도를 측정하고 95% 유의수준에서 일원변량분석법으로 통계분석 하였다. 생활치 미백제가 상아질 접착력을 현저히 감소시켰다. 미백처리 2주 후 레진 접착군은 미백처리하지 않은 대조군과 유의한 차이가 나타나지 않았으며 70% 에탄을 처리군은 미백처리하지 않은 대조군보다는 접착력이 낮았으나, 미백처리 2주 후 레진 접착군과는 차이가 없고 즉시 접착군보다는 높은 접착강도를 나타내었다. 따라서 임상에서 치아미백 후 즉시 레진수복을 할 경우, 에탄올로 전처리하면 상아질에서 레진 접착력을 회복할 수 있을 것으로 사료된다.

• International Journal of Advanced Culture Technology
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• 제3권1호
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• pp.21-30
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• 2015

Ceramic foams are prepared as positive images corresponding to a plastic foam structure which exhibits high porosities (85-90%). This structure makes the ceramic foams attractive as a catalyst in a dry reforming process, because it could reduce a high pressure drop problem. This problem causes low mass and heat transfers in the process. Furthermore, the reactants would shortly contact to catalyst surface, thus low conversion could occur. Therefore, this research addressed the preparation of dry reforming catalysts using a sol-gel catalyst preparation via a polymeric sponge method. The specific objectives of this work are to investigate the effects of polymer foam structure (such as porosity, pore sizes, and cell characteristics) on a catalyst performance and to observe the influences of catalyst preparation parameters to yield a replica of the original structure of polymeric foam. To accomplish these objectives industrial waste foams, polyurethane (PU) and polyvinyl alcohol (PVA) foams, were used as a polymeric template. Results indicated that the porosity of the polyurethane and polyvinyl alcohol foams were about 99% and 97%. Their average cell sizes were approximate 200 and 50 micrometres, respectively. The cell characteristics of polymer foams exhibited the character of a high permeability material that can be able to dip with ceramic slurry, which was synthesized with various viscosities, during a catalyst preparation step. Next, morphology of ceramic foams was explored using scanning electron microscopy (SEM), and catalyst properties, such as; temperature profile of catalyst reduction, metal dispersion, and surface area, were also characterized by $H_2-TPR$ and $H_2-TPD$ techniques, and BET, respectively. From the results, it was found that metal-particle dispersion was relatively high about 5.89%, whereas the surface area of ceramic foam catalysts was $64.52m^2/g$. Finally, the catalytic behaviour toward hydrogen production through the dry reforming of methane using a fixed-bed reactor was evaluated under certain operating conditions. The approaches from this research provide a direction for further improvement of marketable environmental friendly catalyst production.

• Applied Biological Chemistry
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• 제38권5호
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• pp.478-483
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• 1995

한국산 쌀(일반계 일품벼)로부터 돌연변이 억제물질의 구성성분을 확인할 목적으로 methanol 추출물을 용매분획 및 column chromatography하여 활성 spot을 분리하고 정성 분석과 기기분석을 수행하였다. Ether, ethylacetate, butanol 및 수용성 용매 획분 가운데 ether 획분의 억제활성이 가장 높았으며 silica gel column chromatography를 시행하여 성분을 분리하였을 경우 methanol추출물의 억제활성이 80% 이상으로 나타났던 결과와 비교하여 분리가 진행됨에 따라 억제활성은 $0{\sim}30%$로 감소하였다. 활성 물질을 정성분석한 결과 ferric chloride, 2,7-dichlorofluorescein, antimony pentachloride, phosphomolybdic acid, bromothymol blue, rhodamin 6G등의 시약에서는 양성을, ninhydrin, Bial's orcinol 시약에서는 음성을 나타내어 억제활성 물질은 페놀성 화합물과 지질성분인 것으로 조사되었다. 분리된 활성획분을 GC/Mass로 확인한 결과 o-hydroxy benzyl alcohol (saligenin), octanoic acid(caprylic acid), 9,12-cis-octadecadienoic acid(linoleic acid), 11-cis-octadecenoic acid(oleic acid), hexadecanoic acid(palmitic acid), 1H-indole-2-carboxylic acid, 및 1,2-benzenedicarxylic acid(phthalate)가 주요 구성성분인 것으로 분석되었으며 이들 성분들의 억제활성은 표준시약을 사용한 항변이원성 시험에서 재확인되었다.

• 식물조직배양학회지
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• 제25권4호
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• pp.277-282
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• 1998

장미(Rosa sp. cv Paul's Scarlet) 현탁 배양체의 배지에서는 정상적인 성장 조건하에서 cationic peroxidase (POD)만 관찰되었으나, 효모 세포벽으로부터 추출한 숙주 특이성이 낮은 elicitor를 10 mg glucan/L의 농도로 투여하여 24시간 정도 배양하였을 때 기존의 POD와 뚜렷하게 구분되는 anionic POD가 유도됨을 관찰하였다. Elicitor에 의해 유도되는 prominent한 anionic POD (pI 6.1)와 대조구로서 pI 8.4의 cationic isozyme을 분리한 후 효소학적 성질을 비교하였다. Ammonium sulfate농축, ion exchange chromatography, gel filtration chroma tography를 통하여 약 200배로 농축된 두 효소를 분리하였으며, 이 두 효소의 몇몇 기질에 대한 kinetic parameter들은 매우 의미있는 차이를 보여 주었다. 그 중에서 ferulic acid에 대한 Km은 anionic POD의 경우 4.6 mM, cationic POD는 1.38 mM로 측정되었으며, $\textrm{H}_2\textrm{O}_2$에 대한 Km은 각각 anionic POD가 0.72 mM, cationic isozyme이 0.45 mM로 나타났다. 특히 NADH 산화 반응의 활성은 anionic POD가 cationic POD에 비하여 약 2배 높은 것으로 측정되었다. 0.1 mM coniferyl alcohol의 첨가에 의한 NADH 산화 반응의 억제는 anionic POD fraction에서 약 60% 정도 일어난 반면에 cationic POD fraction에서는 약 15% 정도 일어났다.