• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2961-2966
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• 2010

Reduction of carbonyl compounds such as aldehydes, ketones, $\alpha,\beta$-unsaturated enals and enones, $\alpha$-diketones and acyloins was carried out readily with $NaBH_3CN$ in the presence of wet $SiO_2$ as a neutral media. The reactions were performed at solvent-free conditions in oil bath (70 - $80^{\circ}C$) or under microwave irradiation (240 W) to give the product alcohols in high to excellent yields. Regioselective 1,2-reduction of conjugated carbonyl compounds took place in a perfect selectivity without any side product formation.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.448-460
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• 2018

Copper nanoparticle-doped and graphitic carbon nanofibers-covered porous carbon beads were used as an efficient catalyst for treating synthetic phenolic water by catalytic wet air oxidation (CWAO) in a packed bed reactor over 10-30 bar and $180-230^{\circ}C$, with air and water flowing co-currently. A mathematical model based on reaction kinetics assuming degradation in both heterogeneous and homogeneous phases was developed to predict reduction in chemical oxygen demand (COD) under a continuous operation with recycle. The catalyst and process also showed complete COD reduction (>99%) without leaching of Cu against a high COD (~120,000 mg/L) containing industrial wastewater.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.832-842
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• 1996

TAME synthesis was studied in a fixed bed reactor with 3 different types of exchanged resins i.e, Amberlyst-15, Amberlyst-15(wet) and Amberlyst XN-1010. Amberlyst-15 has highest activity, presumably due to the higher reaction participation of the inner active sites of gel shape microparticular resin structure. The optimum reaction conditions for TAME synthesis were found as follows ; reaction temperature of $135^{\circ}C$, molar ratio(MeOH/I.A.A) of 1.0~4.0 and W/F of 2.0~4.0 gr.-cat. hr/gr.-mole. The cross-linking bond of styrene divinyl benzene was observed at $2{\theta}=20$ in XRD pattern. The DSC analysis showed that the thermal stability was in order of Amberlyst-15>Amberlyst-15(wet)>Amberlyst XN-1010. The apparent activation energies of TAME synthesis reaction with Amberlyst-15, Amberlyst-15(wet) and Amberlyst XN-1010 were 12.36, 12.46 and 14.72 kcal/mole, respectively.

• Journal of Veterinary Science
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• v.22 no.1
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• pp.14.1-14.11
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• 2021

Background: Quantitation of urine protein is important in dogs with chronic kidney disease. Various analyzers are used to measure urine protein-to-creatinine ratios (UPCR). Objectives: This study aimed to compare the UPCR obtained by three types of analyzers (automated wet chemistry analyzer, in-house dry chemistry analyzer, and dipstick reading device) and investigate whether the differences could affect clinical decision process. Methods: Urine samples were collected from 115 dogs. UPCR values were obtained using three analyzers. Bland-Altman and Passing Bablok tests were used to analyze agreement between the UPCR values. Urine samples were classified as normal or proteinuria based on the UPCR values obtained by each analyzer and concordance in the classification evaluated with Cohen's kappa coefficient. Results: Passing and Bablok regression showed that there were proportional as well as constant difference between UPCR values obtained by a dipstick reading device and those obtained by the other analyzers. The concordance in the classification of proteinuria was very high (κ = 0.82) between the automated wet chemistry analyzer and in-house dry chemistry analyzer, while the dipstick reading device showed moderate concordance with the automated wet chemistry analyzer (κ = 0.52) and in-house dry chemistry analyzer (κ = 0.53). Conclusions: Although the urine dipstick test is simple and a widely used point-of-care test, our results indicate that UPCR values obtained by the dipstick test are not appropriate for clinical use. Inter-instrumental variability may affect clinical decision process based on UPCR values and should be emphasized in veterinary practice.

• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3535-3541
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• 2014

Bisphenol A is considered as pollutant, because it is toxic and hazardous to living organisms even at very low concentrations. Biological oxidation used for removing this organic from waste water is not suitable and consequently application of catalytic wet oxidation has been considered as one of the best options for treating bisphenol A. We have developed Fe/SBA-15, Ni/SBA-15 and Fe-Ni/SBA-15 as heterogeneous catalysts using the advanced impregnation method for oxidation of bisphenol A in water. The catalysts were characterized with physico-chemical characterization methods such as, powder X-ray diffraction (PXRD), FT-IR measurements, N2 adsorption-desorption isotherm, thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. This work illustrates activity of the catalysts for heterogeneous catalytic degradation reaction revealed with excellent conversion and recyclability. The degradation products identified were not persistent pollutants. GC-MS analysis identified the products: 2,4-hexadienedioic acid, 2,4-pentadienic acid and isopropanol or acetic acid. The leachability study indicated that the catalysts release very little metals to water. Therefore, the possibility of water contamination through metal leaching was almost negligible.

• Journal of the Korean Chemical Society
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• v.45 no.6
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• pp.546-548
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• 2001

Neat chlorosulfonic acid reacts with silica gel to give silica sulfuric acid in which sulfuric acid is immobilized on the surface of silica gel via covalent bond. A combination of silica sulfuric acid and wet SiO$_2$ was used as an effective deacetalizating agent for the conversion of acetals to their corresponding carbonyl derivatives by using microwave irradiation under solvent free conditions.

• The Korean Journal of Ecology
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• v.25 no.6
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• pp.379-382
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• 2002

The present study was to investigate Pb and Cd concentrations in tissues of feral pigeons in urban areas. The Pb levels in bones and livers did not differ between Seoul and Kwangju areas. However, there were significant differences in kidney and liver Cd concentrations between the study sites. These are thought to be a reflection of the metal exposure conditions in the local environment. In particular, metal levels from Seoul were compared with those obtained in the same area between 1991 and 2000 in terms of the long-term biomonitoring approaches. The mean Pb concentrations in bones decreased from 59.1 $\mu$g/wet g in 1991 to 29.5 $\mu$g/wet g in 2000, totaling a reduction in concentrations of approximately 50 percent. However, there were no significant differences in the liver Pb concentrations. Concentrations of Cd in livers and kidneys did not differ between 1991 and 2000.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.133-137
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• 2011

In this study, illite was size-reduced using a wet-ball-milling treatment to improve its dispersion. Changes in illite particle size, size distribution, and dispersion characteristics after varying the treatment period were investigated. And the dispersion and dispersion stability of illite solution after 2 h wet ball milling treatment with different pH conditions were also evaluated. The illite particle size significantly decreased as the treatment time increased and the size reduction effect of wet ball milling deteriorated above 2 h treatment time. In addition, illite particle size was more evenly distributed as the treatment time increased. X-ray diffraction (XRD) analysis showed that no crystal structural changes of illite were induced, but the characteristic peak of illite the weaker due to the size reduction and exfoliation, as the treatment time increased. Zeta potential analysis showed that the illite dispersion improved, as the treatment time increased. The illite wet-ball-mill treated at pH 2 had the lowest dispersion stability. Illite dispersion and dispersion stability increased as pH increased, due to the increase in surface ionization. Hence, the results showed that as the treatment time increased, the illite particle size decreased, and dispersion and dispersion stability improved due to the increase in surface energy and repulsion force between particles.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.216-221
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• 2022

Biocompatible polysaccharide coating technology can be a promising solution to overcome unexpected diseases caused by inflammatory reactions of metallic biomaterials (e.g., stent restenosis, etc.). However, due to their inherent hydrophilicity, it is difficult to maintain the coating layer for a long time in the physiological wet-environment. Herein, catechol functionalized hyaluronic acid was synthesized and introduced to the polymeric stent (polylactic acid) as the adhesive biocoating material. Surprisingly, even with the low degree of substitution of catechol (1.26%), a significant improvement in the underwater stability was observed, confirmed by capillary experiments and spectroscopic analysis. Our results may provide an insight into the positive role of catechol molecular adhesive group in the in-vivo stability of biocoating materials.

• Bulletin of the Korean Chemical Society
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• v.24 no.3
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• pp.400-402
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• 2003