• Journal of Pharmaceutical Investigation
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• 제12권3호
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• pp.74-87
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• 1982

To evaluate the pharmaceutical aspects of solvent deposition method where drug is solvent deposited on the surface of excipients, a study has been made on dissolution characteristics of indomethacin solvent deposited on lactose and potato starch. In a solvent deposition system, the drug-to-excipient ratio and kind of excipient effect much on dissolution rates of indomethacin. The experimental results are as follows: 1) Lactose was shown to be superior to potato starch as excipients in indomethacin solvent deposited. 2) Total amount of indomethacin dissolved from solvent deposition systems at 30 minutes were enhanced about 5 to 23 times compared with that of pure indomethacin. 3) Increased dissotion amount of indomethacin from the solvent deposition systems were observed to be alike in the systems where the drug-to-excipient weight ratios were 1 : 5, 1 : 7 and 1 : 10.

• Bulletin of the Korean Chemical Society
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• 제26권2호
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• pp.238-240
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• 2005

The enthalpies of transfer, ${\Delta}H_t{\Theta}$, of NaI from water to aqueous methanol, ethanol and isopropanol, iPrOH, systems are reported. These data have been analysed in terms of the new solvation theory. These data are considered in terms of the new developed solvation theory including variable ($\alpha$n + $\beta$N), the net effect of the solute on the solvent-solvent bonding, is positive if there is a net breaking or weakening of solvent-solvent bonds. The solvation parameters recovered from the analyses indicate that the net affect of NaI on solvent structure is a breaking of solvent-solvent bonds and that NaI is preferentially solvated by water in all aqueous alcohol systems considered. ($\alpha$n + $\beta$N) values increase with increasing in the size of the alcohol alkyl residue from methanol to iPrOH.

• Journal of Ceramic Processing Research
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• 제18권11호
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• pp.810-814
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• 2017

Proton exchange membrane fuel cells (PEMFCs) are some of the most efficient electrochemical energy sources for transportation applications because of their clean, green, and high efficiency characteristics. The optimization of catalyst layer morphology is considered a feasible approach to achieve high performance of PEMFC membrane electrode assembly (MEA). In this work, we studied the effect of the solvent on the catalyst layer of PEMFC MEAs fabricated using the electrostatic spray deposition method. The catalyst ink comprised of Pt/C, a Nafion ionomer, and a solvent. Two types of solvent were used: isopropyl alcohol (IPA) and dimethylformamide (DMF). Compared with the catalyst layer prepared using IPA-based ink, the catalyst layer prepared with DMF-based ink had a dense structure because the DMF dispersed the Pt/C-Nafion agglomerates smaller and more homogeneously. The size distribution of the agglomerates in catalyst ink was confirmed through Dynamic Light Scattering (DLS) and the microstructure of the catalyst layer was compared using field emission scanning electron microscopy (FE-SEM). In addition, the electrochemical investigation was performed to evaluate the solvent effect on the fuel cell performance. The catalyst layer prepared with DMF-based ink significantly enhanced the cell performance (1.2 A cm-2 at 0.5 V) compared with that fabricated using IPA-based ink (0.5 A cm-2 at 0.5 V) due to the better dispersion and uniform agglomeration on the catalyst layer.

• 한국염색가공학회지
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• 제1권1호
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• pp.47-53
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• 1989

The effect of organic solvent in the dyeing of silk fiber by acid dye was investigated. Acetophenone and benzyl alcohol were shown to be the most effective for the rate of dyeing of silk fiber by Milling Cyanine 5R (C.I. Acid Blue 113), a milling type acid dye, but, with benzyl alcohol, the equilibrium dye uptake was much lower than that in the absence of it. In the presence of solvent, maximum dye uptake shifted to lower temperature than 6$0^{\circ}C$, while without solvent, it was shown at about $60^\circ{C}$. When dyed by Orange II (C.I. acid Orange 7) under same condition equilibrium dye uptake of silk fiber was lower than that for milling type acid dye, and in the presence of benzyl alcohol, still much lower uptake resulted. All these fact reveals that organic solvents in the solvent-assisted dyeing of silk fiber broaden micelle spacings too much, resulting in increased rate of dyeing, and decreased equilibrium dye uptake, contrary to wool.

• Bulletin of the Korean Chemical Society
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• 제26권3호
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• pp.384-392
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• 2005

Solvent effects on the kinetics of bromophenol blue fading have been investigated within a temperature range in binary mixtures of methanol, ethanol, 1-propanol, ethylene glycol and 1,2-propanediol with water of varying solvent compositions up to 40% by weight of organic solvent component. Correlation of logk with reciprocal of the dielectric constant was linear. Finally a mechanism was proposed for the bromophenol blue fading upon SESMORTAC (study of effect of solvent mixture on the one-step reaction rates using the transition state theory and cage effect) model, by means of this model, the fundamental rate constants of the fading reaction in these solvent systems were calculated.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.2989-2994
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• 2013

The solvolysis rate constants of 3,4- (1) and 3,5-dimethoxybenzoyl (2) chlorides were measured in various pure and binary solvents at $25.0^{\circ}C$, and studied by application of the extended Grunwald-Winstein (G-W) equation, kinetic solvent isotope effect in methanolysis and activation parameters. The solvolysis of 1 was interpreted as the unimolecular pathway due to a predominant resonance effect from para-methoxy substituent like 4-methoxybenzoyl chloride (3), while that of 2 was evaluated as the dual mechanism, with unimolecular or bimolecular reaction pathway according to the character of solvent systems (high electrophilic/nucleophilic) chosen, caused by the inductive effect by two meta-methoxy substituents, no resonance one. In the solvolyses of 1 and 2 with two $-OCH_3$ groups, the resonance effect of para-methoxy substituent is more important to decide the mechanism than the inductive effect with other corresponding evidences.

• Journal of Preventive Medicine and Public Health
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• 제25권2호
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• pp.162-171
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• 1992

The hematologic effect by low-concentration and repeated exposure to mixed organic solvent remains obscure. This study was performed to evaluate the hematologic effect by mixed organic solvent exposure, especially on the type of anemia by mean corpuscular volume(MCV) and red blood cell distribution width(RDW). The subject were 64 organic solvent workers(male 4, female 60) and 78 general workers(male 18, female 60) who showed anemic tendency in worker's health examination which carried out by Pusan Paik Hospital from January to December, 1988. The author gained some hematologic findings(hemoglobin, hematocrit, RBC, WBC, MCV, MCHC, platelet count, ESR, RDW) from auto-analysis method by coulter counter S plus IV, and compared the type of anemia by MCV and RDW. In the pilot study for estimating the prevalence of anemia according to the type of b, the prevalence rate was higher in organic solvent workers than in public officials as 10.9% and 4.1% respectively. There were statistical significance in the value of hemoglobin, hematocrit, MCV, MCHC, platelet count, ESR, RDW between the two study groups with more severe anemic tendency in organic solvent workers. The type of anemia in organic solvent workers was microcytic and anisocytic with the mean value of $68.28{\pm}8.3fL$ of MCV and $19.1{\pm}4.0%$ of RDW.

• 한국의류학회지
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• 제19권3호
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• pp.548-559
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• 1995

The purpose of this study was 1) to investigate the effect of drycleaning on the removal of microorganisms according to on the conditions or the kinds of drycleaning solvent about the Quantity of microorganism which remains in kinds of the drycleaning solvent and the sludge after drycleaning. 2) to investigate the removal effect of :microorganisms in using drycleaning solvent repeatedly 3) to investigate the kinds of microorganism living in textiles. The re, ;ultras of tai, ; study were as follows; 1) less microorganisms remains in perchloroethylen than in petroleum solvent. The most microorganisms was isolated at the beginning stage during the drycleaning. 2) In fresh drycleaning solvents, Pseudomonas aeruginosa ATTIC 27853, taphylococcsu atreus ATTIC 6538. and Candida albicans 10529 were killed immediately, while in case of pesters solvents used for 6 month-drycleaning, Pseudomonas Aeruginosa ATTIC 27853 were survived a lot of still in 17 days. 3) On the kind of bacteria in textile goods, Pseudomonas acidovorans and Ewsipelothrix rhusiopathiae are isolated. a genus Rhodetorula is observed through microscope. On the kind of fungi in textile goods, genus Penicillins and genus Apergillus are found through microscope, genus Caddie and genus Trichophyton are found with shapes.

• Journal of Photoscience
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• 제8권1호
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• pp.33-37
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• 2001

Picosecond absorption spectroscopy has been employed in the study of the solvent dynamics of 1, 2, 4, 5-tetracyanobenzene/biphenyl derivative radical ion pairs, and the resulting rates of radical ion pair separation are faster in acetonitrile than in dichloromethane. In an effort to account quantitatively for such solvent effect on the rate of radical ion pair separation, an equation for the rate of radical ion pair separation is introduced, in which the rate depends exponentially on the electrostatic interaction energy in the radical ion pair. In our analysis of the types of electrostatic interaction energy based on the conducting spheres in dielectric continuum was chosen, and the rate equation employing this electrostatic energy provided information on the distance on the distance of radical ion pair separation and solvation energy of the radical ion pair, thereby providing quantitative explanation for the observed solvent effect on the rate of radical ion pair sepaaration.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.87-89
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• 2003

YBa$_2$Cu$_3$$O_{7-x}$ thin films were fabricated by MOD-TFA process via dipping method on LaAlO$_3$(LAO) single crystalline substrates. In this study, we investigated effect of solvent on the microstructure and crystallinity of YBCO thin films. The YBCO films derived from solvent with low boiling point has good surface morphologies.s.