• 청정기술
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• 제22권4호
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• pp.269-273
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• 2016

The benzylic bromination of methoxyimino-o-tolyl-acetic acid methyl ester (1) into (2-bromomethyl-phenyl)-methoxyimino-acetic acid methyl ester (2) using N-bromosuccinimide in the presence of 2,2'-azobisisobutyronitrile in various reaction solvents were investigated. The efficiency of the reaction was found to be sensitive to the kind of reaction solvents. We found the benzylic bromination of 1 to 2 can be performed in 1,2-dichlorobenzene as reaction solvent superior to the classic Wohl-Ziegler procedure in both reaction time and isolated yield (8 h vs 12 h, 92 vs 79%). This system provides clean, rapid, and high-yielding reactions with replacement of conventional solvents, such as tetrachloromethane, by less-toxic 1,2-dichlorobenzene.

• 한국세라믹학회지
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• 제50권4호
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• pp.294-300
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• 2013

The effect of chemical treatments of porous silicon in organic solvents on its nanostructural and optical features was investigated. When the porous Si was dipped in the organic solvent with various PH values, the morphological, chemical, and structural properties of the porous silicon was sensitively affected by the chemical conditions of the solvents. The size of silicon nanocrystallites in the porous silicon decreased from 5.4 to 3.1 nm with increasing pH values from 1 to 14. After the samples were dipped in the organic solvents, the Si-O-H bonding intensity was increased while that of Si-H bonding decreased. Photoluminescence peaks shifted to a shorter wavelength region in the range of 583 to 735 nm as the pH value increased. PL intensity was affected by the size as well as the volume fraction of the nanocrystalline silicon in the porous silicon.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.310-313
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• 2000

Polyaniline Emeraldine Base (PANI EB) polymerized by chemical oxidative polymerization was doped with Camphorsulfonic Acid(CSA). Polyaniline-Camphorsulfonic Acid Emeraldine Salt(PANI-CSA ES) solutions were solved in organic solvents and sonificated at the room temperature for different solvents in PANI-CSA ES solution and sonification time. PANI-CSA ES solutions was coated on PET films using bar coater. 1-Step oxidatively-polymerized Polyaniline-Camphorsulfonic Acid Emeraldine Salt(PANI-CSA ES) was solved in m-cresol:chloroform 1:1 co-solvents and their solution was bar-coated on PET film. The surface resistivities of these coated films were measured, The surface resistivity of PANI-CSA ES solution in m-cresol:chloroform 1:1 co-solvent system was 5${\times}$10$^2$$\Omega$/$\square$.

• Journal of Preventive Medicine and Public Health
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• 제16권1호
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• pp.31-34
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• 1983

For the study of the applicability of predictive equation of subjective symptoms of workers using organic solvents, 67 male workers using organic solvents were selected. The predictive equation was quotated from previous Cheon's study. All the datas of necessary variables were gained. The predictive values and observed values were compared. The results were summarized as below; 1. The difference between predictive values and observed values were characteristically large. The coefficient of determination between the two values was 0.0024. 2. The $R^2$ value of multiple stepwise regression equation derived from present study was 0.2827.

• 융복합기술연구소 논문집
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• 제3권2호
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• pp.1-6
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• 2013

The ionic liquids are known to potential alternative solvents capable of replacing the commercial solvents in various processes including those in nuclear fuel cycle. As to the material, a number of studies have already reviewed the interesting results and addressed the spectroscopic as well as electrochemical behaviors of metal elements included in spent nuclear fuels. It has found that the important properties of metal ions in TBP dissolved ILs have led the development of alternative technologies to traditional solvent extraction processes. On the other hand, the electrochemical deposition of metal ions in ILs have been investigated for the application of the solvents to aqueous as well as to non-aqueous processes. In this work, a review on the application of ILs in nuclear fuel cycle is briefly presented to understand the notable researches on ILs focusing on aqueous processes.

• 한국염색가공학회지
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• 제2권1호
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• pp.1-7
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• 1990

The cleaning resistance of tanned chrome garment leathers was investigated by using drycleaning solvents. Hydrocarbon, perchloroethylene and fluorocarbon (F-113) were used as solvent. Various test methods, such as color difference test, surface view by scanning electron microscope, mechanical properties measured by KES-FB System and their hand values and wearing abilities are carried out in this study. The results can be obtained as follows: 1. Fluorocarbon type (F-113) was demonstrated a suitable solvent for drycleaning of leather. 2. Perchloroethylene showed the worst in fading and stiffening among three different types of solvents.

• Bulletin of the Korean Chemical Society
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• 제17권2호
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• pp.128-131
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• 1996

From Raman spectra, the ${\nu}g$C=O frequencies of 4-substituted benzaldehydes were found to correlate with the ${\sigma}_p$ values of the 4-x atom or group as well as the acceptor number (AN) values of solvents. In various solvents, the ${\nu}g$C=O frequency of benzaldehyde decreased upon the increase of benzaldehyde concentration. This shift was mainly due to the hydrogen bonding between the carbonyl oxygen and/or aldehydic proton of benzaldehyde and the solvent molecules. Over the 1-80 volume % change, the ${\nu}g$C=O frequency of benzaldehyde down shifted from 1709.4 $cm^{-1}$ to 1700.2 $cm^{-1}$ in CCl4 solution and from 1703.0 $cm^{-1}$ to 1698.0 $cm^{-1}$ in $C_2H_5OH$ solution. This is due to the fact that hydrogen bonding between the benzaldehyde and C2H5OH was much stronger than that between the benzaldehyde and the other solvents.

• Bulletin of the Korean Chemical Society
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• 제8권4호
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• pp.341-344
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• 1987

The fluorescence quantum yield of khellin is sensitive to temperature and to the nature of solvents, especially the proton-donating ability in solute-to-solvent hydrogen bonding. The intersystem crossing quantum yields are 0.4 and 0.15 in acetonitrile and ethanol, respectively. The fluorescence quantum yields in ethanol and isopentane at 77 K are 0.61 and 0.07, respectively, both of which are much larger than the values at room temperature. The phosphorescence lifetime is relatively long and decreases with decreasing solvent polarity. The phosphorescence to fluorescence quantum yield ratio is very small and remains unchanged in various solvents. The results suggest that internal conversion is an important decay channel of the excited singlet state of khellin, especially in the hydrogen-bonding hydroxyl solvents.

• 생물환경조절학회지
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• 제19권3호
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• pp.147-152
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• 2010

화분량은 '금천' 수박을 제외하고 응화 1개당 10mg 이상이었다. '복' 수박은 1화당 화분무게가 13.8mg이었고, '스피드꿀' 수박은, 12.1mg으로 겨울철 저온기 재배에 인공수정용 화분생산 품종으로 적당한 것으로 판단된다. 유기용매 침지 후 즉시 건조된 화분발아율은 '금천' 수박이 67%로 기장 낮았고 '아폴로꿀' 수박이 92%로 가장 높았다. 유기용매에 15일간 저장했을 경우 '복' 수박 화분의 발아력이 74%로 가장 높았다. 저장 24일 후에는 5품종 모두 25% 이하의 발아율을 나타내었다. '금천'과 '삼복꿀' 수박의 화분관 신장속도는 $50{\mu}m/hr$ 미만(저장 24일)으로 다른 품종보다 낮았으며, 벌이도중 화분관이 파열되는 경우도 발생되었다. 유기용매 저장 24시간 후 화분발아율은 pentane, ethyl ether, n-hexane, ethyl acetate, acetone에서 각각 45, 39, 34, 23, 19% 순이었고 유기용매 침지시간이 길어질수록 화분활력이 급격히 감소되었다. 화분 표피는 유기용매에 저장한 시간이 길어질수록 장해를 많이 받았는데 유기용매의 종류에 따라 장해정도가 달랐다. '복' 수박이 화분량, 화분활력, 저장성이 우수하였는데 저온기 착과율 증진을 위한 화분생산 품종으로 보여진다.

• 한국지반환경공학회 논문집
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• 제11권5호
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• pp.61-67
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• 2010

본 연구는 GC/FID에서 염화유기용제(PCE와 TCE)와 그 부산물(cis-DCE, VC, 그리고 Ethylene)의 분석을 위하여 액-액추출법의 대안인 SPME방법을 연구하였다. 실험인자로써 fiber의 종류, 흡착 및 탈착시간, headspace의 부피, 염석효과, 그리고 교반효과에 대하여 실험을 실시하였다. 염화유기용제와 부산물의 분석을 위하여 fiber는 CAR/PDMS, 흡착과 탈착시간은 $250^{\circ}C$에서 20분과 5분, 염첨가량 25%와 교반이 병행되었을 때에 최적의 분석조건으로 도출되었다. CAR/PDMS fiber에서 분석물의 추출감도는 PCE>TCE>cis-DCE>VC>Ethylene순으로 조사되었다. 염화유기용제와 부산물의 농도 $10{\mu}g/L$에서 $500{\mu}g/L$까지의 직선상의 상관계수($R^2$)는 0.912에서 0.999로 조사되었으며, $500{\mu}g/L$(5회 분석)일 때에 상대표준편차(% RSD)는 2.1%에서 3.6%로 나타났다. 마지막으로 본 연구에서 염화유기용제와 부산물의 검출한계(LOD)는 $0.5{\mu}g/L$에서 $10{\mu}g/L$로 관측되었다.