• Journal of Korean Society of Environmental Engineers
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• v.36 no.1
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• pp.49-57
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• 2014

The survey of nitrosamine occurrence at Nakdong river is conducted in this study. According to the study results, six nitrosamine compounds (NDEA as N-nitrosodiethylamine, NDPA as N-Nitrosodi-n-propylamine, NDMA as N-nitrosodimethylamine, NMEA as N-nitrosomethylethylamine, NDBA as N-nitrosodi-n-butylamine, and NDPHA as N-Nitrosodiphenylamine) were detected at the Nakdong river. Among these, NDEA and NDPA are the most important compounds in terms of the nitrosamine contamination of Nakdong river. The detected concentration of NDEA exceeded the CDHCS (California Department of Health Care Services) response level of 100 ng/L at several sites. The detected concentration of NDPA approached the response level (500 ng/L) at few sites. When all nitrosamine concentrations were summed up, the maximum concentration of 735.7 ng/L was detected at the Nakdong river.

• Analytical Science and Technology
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• v.15 no.2
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• pp.135-141
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• 2002

The new tridentate poly-amine ligands, N,N-Bis(2-amino-ethyl)-methyl amine${\cdot}$2HBr (BAMA${\cdot}$2HBr), N,N-Bis(2-amino-ethyl)-ethylamine${\cdot}$2HBr (BAEA${\cdot}$2HBr), N,N-Bis(2-amino-ethyl)-propylamine${\cdot}$2HBr (BAPA${\cdot}$2HBr) and N,N-Bis(2-amino-ethyl)-butylamine${\cdot}$2HBr (BABA${\cdot}$2HBr) were synthesized as their dihydrobromic-salt and characterized by EA, IR, NMR and Mass spectroscopy. The protonation constants of the ligands and stability constants of transition metal(II) complexes were determined in aqueous solutions by potentiometry and compared with diethylenetriamine. Stability constants for transition metal complexes of ligands are in the order of BAMA < BAEA < BAPA > BABA. The larger value of stability constants of BAPA compared to these BABA, may be attributed to the more distorted structure of the complex due to the increased steric crowding caused by the presence of the bulky N-butyl group.

• YAKHAK HOEJI
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• v.20 no.3
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• pp.156-161
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• 1976

The salting in and salting out of Octoxynol, N.F., a nonionic polyoxyethylated surfactant by n-alkylamine hydrochlorides ws investigated by measuring their effect on the cloud point of the surfactant at various salt concentrations. The carbon number of the alkyl chain was varied from zero to twelve. Ammonium chloride, methylamine hydrochloride and ethylamine hydrochloride tended to salt out the surfactant, lowering its cloud point in proportion to the salt concentration. n-Ankylamine and n-butylamine hydrochlorides showed salting-out effect at low concentrations of the electrolyte, while their effects were leveled off and showed rather salting-in trend at higher concentrations of the electrolyte. These salting-in effect was ascribed to the formation of a hydrotropy of the n-alky lammonium cations with the surfactant. The higher homolog compounds of n-alkylamine hydrochlorides showed extraordinarily high salting-in effect at very low oncentrations of the electrolyte. These large salting-in effects were more drastic as the chain length was getting longer. These large increases of the cloud point of the surfactant were attributed to the formation of mixed micelles of n-alkylammonium cations with the polyoxyethylated surfactant.

• Journal of the Korean Chemical Society
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• v.56 no.5
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• pp.563-570
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• 2012

Solid acid Mo(VI)/$ZrO_2$ with 2-10% Mo(VI) was coated on honeycomb monoliths by impregnation method. These catalytic materials were characterized by BET, $NH_3$-TPD/n-butylamine back titration, PXRD and SEM techniques. Phenyl salicylate (Salol) was synthesized via transesterification of methyl salicylate and phenol over these catalytic materials. An excellent yield (91.0%) of salol was obtained under specific reaction conditions. The effect of poisoning of acid sites of the catalytic material by adsorbing different bases and its effect on total surface acidity, powder XRD phases and catalytic activity was studied. A triangular correlation between the surface acidity, powder XRD phases and catalytic activity of Mo(VI)/$ZrO_2$ was observed. The thermally regenerated catalytic material was reused repeatedly with a consistent high yield of salol.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2633-2636
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• 2010

3-Acetyl-5-benzoyl-6-methyl-2-phenyl-4H-pyran-4-one has been subjected to condensation with a series of primary amines (ethylamine - octylamine) to clarify the proposed mechanism in our previous study. The reactions of the shorter amines of the series (ethylamine - butylamine) yielded unsymmetric pyridinone products, whereas the other amines (pentylamine - octylamine) yielded symmetrical pyridinones. The starting material and the products as well as the intermediates have been subjected to theoretical analysis by quantum chemical calculations at B3LYP/6-31G(d,p) level, which provided supporting data for the experimental findings.

• YAKHAK HOEJI
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• v.54 no.6
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• pp.466-473
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• 2010

A series of $3{\beta}$-substituted 5-androstene-$17{\beta}$-carboxamides were synthesized from analogs of $3{\beta}$-hydroxy-5-androstene-$17{\beta}$-carboxylic acid (1) with tert-butylamine, N,N-diethylamine and 3-aminopyridine and some compounds were epoxidized with mCPBA. A rat prostate testosterone $5{\alpha}$-reductase inhibitory activity of synthesized compounds was assessed by radioimmunoassay using [1,2,6,7-3H]-testosterone as substrate. All synthesized compounds showed lower activity than finasteride and the N-(3-pyridino)-$3{\beta}$-carboxycarbonyloxy-5-androstene-$17{\beta}$-carboxamide (12) showed weak inhibitory activity ($IC_{50}$: $2.4{\times}10^{-7}M$).

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.332-332
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• 2011

The adsorption and desoprtion properties on Pt(111) of chiral molecules, propylene oxide (PO) and 1,3-dimethyl butylamine (DMBA), have be characterized in utrahigh vacuum. Precision-doses of PO and DMBA onto a Pt(111) surface at 90 K have been achieved with a directed tubular molecular doser controlled by a micron-sized orifice and the reservoir gas pressure. Temperature-programmed desorption (TPD) mass spectra have been employed together with low-energy electron diffraction (LEED) analyses. In addition to the separate adsorption behaviors of PO and DMBA, the enantioselective adsorption of R- and S-PO on Pt(111) precovered with R- or S-DMBA have been investigated thoroughly, and the results will be presented.

• Journal of Dairy Science and Biotechnology
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• v.34 no.3
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• pp.187-191
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• 2016

Biogenic amines have been used as chemical indicators of fermented foods. So far, several chromatography methods have been developed to detect biogenic amines in foods. However, few methods have identified these compound in domestic cheese. We analyzed the biogenic amines (histamine dihydrochloride, tyramine hydrochloride, ${\beta}$-phenylethylamine hydrochloride, putrescine dihydrochloride, cadaverine, spermidine, tryptamine hydrochloride, ethanolamine hydrochloride and butylamine) in cheese by using HPLC. The calibration curves of the biogenic amines were found to be linear over the concentration range of 10-50 ppm with a correlation coefficient of above 0.99. The limit of detection (LOD) and limit of quantitation (LOQ) of the biogenic amines in the given order were 3.7 and 11.3 ppm, 3.4 and 10.4ppm, 3.4 and 10.3 ppm, 4.0 and 12.2 ppm, 3.4 and 10.4 ppm, 3.4 and 10.5 ppm, 3.5 and 10.7 ppm, 4.1 and 12.5 ppm, and 3.4 and 10.4 ppm, respectively. Recovery rates of the biogenic amines in the given order were 112, 104, 93, 108, 91, 102, 101, and 92%, respectively. The findings of this study suggest that HPLC is a suitable method for the determination of biogenic amines, thereby indicating its potential application in the quality control of aging cheese.

• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.73-77
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• 2014

Black fermented garlic includes many pharmacological components. Therefore, in this study, black fermented garlic wine was manufactured and its flavor compounds were investigated difference of aging chips from America and France. The fermented wine was stored at $10^{\circ}C$ for 6 months. GC/MS was used for the flavor components analysis. Wine using American chip contained 2-methyl-1-propanol, 3-methyl-1-butanol, 2-methyl-1-butanol, acetaldehyde, butanoic acid, octanoic acid, 1,1-diethoxyethane, and allyl methyl sulfide. 1-Propanol, 2-methyl-1-propanol, 3-methyl-1-butanol, acetaldehyde, acetic acid, propanoic acid, butanoic acid, octanoic acid, 2-heptanone, 1,1-diethoxyethane, N-amino32-hydroxypropanamidate, n-butylamine, and chloroacetonitrile were detected as major flavor compounds using France chips. Especially, the wine contained allyl methyl sulfide that was resulted from black fermented garlic. There were more compounds that smell like fruit in the wine using American chips relatively. And allyl methyl sulfide was detected only in the wine using America chips. Whereas acetic acid was detected only in the wine using France chips.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.81-87
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• 2019

In this study, synthetic methods and physical properties for a new class of glycidyl azide polymer (GAP) were investigated for energetic thermoplastic elastomers (ETPE). Four kinds of GAP copolymer polyols were synthesized by introducing nucleophiles such as azide, alkoxide and alkyl amine into poly(epichlorohydrin) (PECH). The GAP copolymer synthetic reaction can be evaluated as an environmental benign and efficient synthetic method due to the simultaneous one-step reaction using two kinds of nucleophiles and the complete consumption of sodium azide. The relative stoichiometric substitution ratio analysis and the progress of reaction were checked and monitored by inverse gated decoupled $^{13}C$ NMR and Fourier transform infrared (FT-IR) spectroscopy. The glass transition temperature and molecular weight were measured by differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) analysis. The synthesized poly($GA_{0.8}-butoxide_{0.2}$), poly($GA_{0.7}-n-butylamine_{0.3}$), poly($GA_{0.7}-dipropylamine_{0.3}$) and poly($GA_{0.7}-morpholine_{0.3}$) had a glass transition temperature ranged from -39 to $-26^{\circ}C$.