• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.173-176
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• 2012

Chlorine dioxide has an excellent ability to sterilize and deodorize and is harmless to humans. However, it is very unstable and explosive as it is highly concentrated, thus its use in the air clean filed has been limited. Therefore, there is a demand to develop the system to produce a low concentration of chlorine dioxide sustainedly. Here, for a first step in the development of the system on the sustained production of chlorine dioxide, the use of polymer hydrogels was investigated. P(MMA-co-HEMA) hydrogel particles were prepared via dispersion photopolymerization and sodium chlorite and citric acid were loaded respectively in the hydrogel particles. When sodium chlorite and citric acid were reacted with not loaded in the hydrogels, rapid production of chlorine dioxide occurred and the concentration of chlorine dioxide decreased over time. However, when sodium chlorite and citric acid were loaded respectively in the hydrogel particles and reacted, chlorine dioxide was produced slowly and sustainedly because the release of sodium chlorite and citric acid from the hydrogels delayed the reaction between them. The result shows that the use of P(MMA-co HEMA) hydrogels has the potential to develop the system on the sustained production of chlorine dioxide.

• Applied Biological Chemistry
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• v.20 no.1
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• pp.117-122
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• 1977

Development of new burning additives against nitrate salts used in past tobacco industry examined to reduce harmful nitrogenous compounds in smoke. Among several additives treated, the best effect by means of elevation of combustibility and reduction of tar and nicotin contents in smoke was observed by adding sodium citrate from 0.6 to 1% in tabacco. The following results were obtained through investigating combustibility, chemical composition, and differential thermal analysis of the tabacco treated with the buring additives. 1) The close relation was observed between the levels of the smoke components and combustibility of the treated tabacco. 2) Differential thermal analysis (D.T.A.) of citrate-treated tobacco shows an increase in H. Value and a decrease in L. Value as compared with other tobacco sample. 3) The D.T.A. of sodium-nitrate and sodium-citrate shows that sodium-nitrate gives endothermal reaction at $270^{\circ}$ and $310^{\circ}$ and sodium citrate gives exothermal reaction at $290^{\circ}$ with endothermal reaction at $170^{\circ}\;and\;310^{\circ}$. 4) $Na_3-citrate-treated$ tobacco shows an increase in smoke generation between room temperature and $350^{\circ}$ (Zone A) and a decrease in smoke generation between $350^{\circ}$ and $900^{\circ}$ (Zone B) compared with untreated tobacco. The smoke from these tobacco also contains lower levels of Tar, Nicotine, Phenols, Nitrogen oxides and Benzpyrene, and elevation of static Burning rate.

• Journal of Internet of Things and Convergence
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• v.9 no.3
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• pp.27-33
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• 2023

In this study, it was analyzed with the dyeing pattern of Diospyros kaki Thunb (persimmon) and was tried to numerically evaluate how the dyeing pattern in silk fabrics and cells was changed by different mordants. When the dyed silk fabrics were sufficiently dried, the silk fabrics were found to have a pale yellow color. Interestingly, iron II sulfate mordant changed the color change the most, silk fabrics were dyed with a color close to brown or dark purple. For numerical analysis, 19% and 62.5% color changes could be induced by sodium tartrate plus citric acid and copper acetate, respectively. Iron II sulfate induced the greatest difference than that of untreated mordants at 88%. About 5% and 10% of Chinese hamster ovary (CHO) cells were stained by sodium tartrate plus citric acid and copper acetate, respectively. The staining effect induced by iron II sulfate was about 2.4 times higher than the staining effect by sodium tartrate plus citric acid. In previous studies, staining results have been visually confirmed. However, this results not only visually confirmed the dyeing, but also quantified the color change. In particular, if numerical results are continuously integrated into big data, any researcher will be able to easily obtain similar results even if the method, time, volume, etc. are changed. In addition, the numerical data of this study is considered to be an important basis for building a database for IoT construction and computer analysis.

• Journal of Industrial Technology
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• v.29 no.B
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• pp.229-232
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• 2009

We prepared gold nanoparticles (Au NPs) by reduction-oxidation reaction between $HAuCl_4$ and trisodium citrate and measured the size and morphology of Au NPs by TEM for various molar ratios of $HAuCl_4$ to citrate and for various concentrations of $HAuCl_4$. UV-vis spectroscopy was used to characterize the optical properties of Au NPs. Au NPs in the size range from 14.3 nm to 20.3 nm were prepared with monodisperse distribution.