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Li, Rongchun
- Journal of the Korean Chemical Society
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- v.56 no.4
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- pp.464-467
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- 2012
A novel chitosan derivative with double quaternary ammonium salt-2-pyridine-acetyl-N-trimethyl chitosan chloride (PATMCS) was synthesized and the antioxidant activity of PATMCS against hydroxyl radicals was assessed. The results indicated that PATMCS had potent hydroxyl scavenging activity. The $IC_{50}$ of PATMCS was 0.13 mg/mL. PATMCS showed 100% scavenging effect at a dose of 0.8 mg/mL which markedly better than that of N-trimethyl chitosan chloride (TMCS). It was confirmed that quaternary chitosan derivatives showed potent antioxidant activity. PATMCS has double quaternary ammonium salt structure in the molecules. Therefore, the antioxidant activity of PATMCS was better than TMCS. The above results are theoretically fundamental for further development and making use of chitosan resources to prepare new antioxidants.
https://doi.org/10.5012/jkcs.2012.56.4.464 인용 PDF KSCI KPUBS HTML

Chaniago, Yus Donald;Lee, Moonyong
- Journal of Industrial and Engineering Chemistry
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- v.67
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- pp.255-265
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- 2018
The huge amount of solvents used in the semi-conductor and display industry typically result in waste of valuable solvents which often form complex azeotropic mixtures. This study explored a recovery process of a quaternary waste solvent, comprising methyl 2-hydroxybutyrate, propylene glycol monomethyl ether acetate, ethyl lactate, and ethyl-3-ethoxy propionate. In this study, a novel shortcut column method with a graphical approach was exploited for the distillation column design of complex quaternary azeotropic mixtures. As a result, the proposed shortcut method and design procedure solved the complex separation paths successfully with less computational efforts while achieving all requirements for component purity.
https://doi.org/10.1016/j.jiec.2018.06.036 인용 KSCI

Jang, Ji-Woong;Kim, Sang-Hyo;Lim, Dae-Woon
- The Journal of Korean Institute of Communications and Information Sciences
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- v.34 no.2C
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- pp.158-162
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- 2009
In this paper, we propose a quaternary sequence with good autocorrelation property. New quaternary sequence is generated by using inverse Gray mapping and binary sequence with ideal autocorrelation. And the maximum magnitude of nontrivial correlation value is 3. Proposed quaternary sequence has only one 1 in one period, so called almost binary sequence. Therefore the balance property is not good, but value of its weight function is nearly 0.
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Sung, A-Young
- Journal of Korean Ophthalmic Optics Society
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- v.10 no.4
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- pp.261-266
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- 2005
Quaternary ammonium compounds(QACs) are some of the most commonly used antimicrobials. Antimicrobial polymers have been used as biomedical devices. In this Study, We synthesized new methacrylate monomers including quaternary ammonium moieties for preparation of contact lens, And also, we tested for antimicrobial activities against S. aureus, E. coli and P. aeruginosa. They showed much higher antimicrobial activities against all than the polymers of no including quaternary ammonium.
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