• Transactions of the Korean hydrogen and new energy society
• /
• v.33 no.1
• /
• pp.28-37
• /
• 2022

In this study, we synthesized a poly(pheneylene oxide) (PPO)-based organic/inorganic composite membrane having silicotungstic acid (STA) for the development of an anion exchange membrane with excellent ionic conductivity and physicochemical stability. The organic/inorganic composite membranes were prepared by introducing different STA contents (0 wt%, 10 wt%, 30 wt%, and 50 wt%) into the quaternizaed(Q)-PPO matrix. The prepared anion exchange membranes were subjected to structural analysis by proton neclear magnetic resonance and Fourier transform infrared, and thermal behavior of membranes was confirmed by thermogravimetric analysis. Among the prepared composite membranes, the ion conductivity of Q-PPO/STA-50 (40.5 mS cm^-1) showed 1.46 times compared to that of the pristine membrane (27.6 mS cm^-1). Therefore, these results demonstrated that organic/inorganic composite membranes are promising candidates for application of anion exchange membranes.

• Microbiology and Biotechnology Letters
• /
• v.13 no.3
• /
• pp.285-287
• /
• 1985

To investigate effective constituents of the many taste components in ordinary Korean soy sauce, we analyzed free amino acids, organic acids, free sugars and saline as taste components in ordinary Korean soy sauce, and determined sensory score of the ordinary Korean soy sauce taste with 45 persons of the trained pannels. The relationships between original data transformed with variables and sensory score of the ordinary Korean soy sauce were analyzed by stepwise multiple regression analysis. Eighty five percents of the ordinary Korean soy sauce taste is affected by twenty one kinds (Isoleucine, Leucine, Valine, NaCl, Lactic acid, Alanine, Phenylalanine, Tartaric acid, Sugar(\ulcorner), Proline, Malic acid, Glycine, Tryptophan, Arginine, Glutaric acid, Maltose, Histidine, Glucose, Fructose and Serine) of the taste components by stepwise multiple regression analysis of original data. Eighty one percents of the ordinary Korean soy sance taste is affected by sixteen kinds (Lactic acid, NaCl, Fumaric.Succinic acid, Tyrosine, Tartaric acid, Glycine, Malonic acid, Malic acid, Tryptophan, Glutaric acid, Methionine, Histidine, Cysteine, Maltose, Fructose and (Glutamic acid) of the taste components by stepwise multiple frgression analysis of original data transformed with square root. Eighty five percents of the ordinary Korean soy sauce taste is affected by nineteen kinds (Fumaric.Succinic acid, Lactic acid, Phenylalanine, NaCl, Tyrosine, Sugar(\ulcorner), Tartaric acid, Leucine, Glutaric acid, Methionine, Glycine, Tryptophan, Histidine, Proline, Cysteine, Glutamic acid, Maltose, Threonine and Oxalic acid) of the taste components by stepwise multiple regression analysis of original data transformed with logarithm.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.8
• /
• pp.2375-2380
• /
• 2013

Two metal-organic frameworks based on the connectivity co-effect between rigid benzenedicarboxylic acid and bridging ligand have been synthesized $[Zn_2(3-NO_2-bdc)_2(4,4'-bpy)_2H_2O]_n$ (1), $[Co(3-NO_2-bdc)(4,4'-bpy)H_2O]_n$ (2) (where $3-NO_2-bdcH_2$ = 3-nitro-1,2-benzenedicarboxylic acid, 4,4'-bpy = 4,4'-bipyridine). The two novel complexes were characterized by IR spectrum, elemental analysis, fluorescent properties, thermogravimetric analysis, single-crystal X-ray diffraction and powder X-ray diffraction (PXRD). X-ray structure analysis reveals that 1 and 2 are two-dimensional (2D) network structures. Complex 1 and complex 2 belong to triclinic crystal with P-1 space group. The luminescence measurements reveal that two complexes exhibit good fluorescent emissions in the solid state at room temperature. Also, thermal decomposition process and powder X-ray diffraction of complexes were investigated.

• Journal of Korean Society of Water and Wastewater
• /
• v.14 no.1
• /
• pp.54-61
• /
• 2000

Recently, our circumstances are threatened by an accident that leakage of under ground storage tank and illegal dumping of synthetic organic compounds at chemical plants and many treatment methods, Activated carbon adsorption, Ozonization, Membrane filtration and Photocatalystic oxidation, are developed to remove such a synthetic organic compounds. And it has reported that Activated carbon adsorption have a great removal efficiency to nondegradable matters and organic compounds which have a high molecular weight. Comparing with other adsorbents, Activated carbon adsorption have a worse efficiency when ad desorption speed is low. Thus improved type of adsorbents was invented and one of those is Activated Carbon Filter. The purpose of this study was getting information about adsorption characteristic phenol which can be applied Activated Carbon Fiber and Granular Activated Carbon. In detail, With comparing removal characteristics of phenol in the presence Humic Acid using Activated Carbon Fiber(ACF) and Granular Activated. Carbon(GAC), it is to certify an effective application of Activated Carbon Fiber. At the range of this study, Batch test, Isotherm adsorption test and Factorial analysis, following conclusion were obtained from the results of this study. Batch test was carried to know time of adsorption equilibrium. In this study about time of adsorption equilibrium by ACF was faster than GAC's, for developed micropore of ACF. From the result of phenol adsorption test, High removal rate of adsorption is shown at pH 5. The result of lsotherm adsorption test, it has represented that the Freundlich's isotherm is most suitable one in others, that a ACF's adsorption capacity is more excellent than GAC's. Adsorption of phenol exiting humic acid is decreased getting raised humic acid concentration. Since ACF's micropore is developed at this time, an effect of high molecular humic acid is lower. Factorial analysis was carried to know about Main effect which was injection dosage of adsorbent in the range of this study.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.121-121
• /
• 2022

When 7 kg·10a^-1, which is less than the nitrogen standard application amount of 9 kg·10a^-1, is applied, the protein content is lowered and the palatibility is improved. In order to examine the applicability of nitrogen fertilization of 7 kg·10a^-1 nationwide, soil samples were collected from 240 paddy fields in 8 provinces in 2021, and the organic matter content, effective phosphoric acid, and effective silicic acid were analyzed for each sample. As a result of one-way ANOVA analysis between samples collected for each province, there was no significant difference in the content of organic matter, effective phosphoric acid, and effective silicic acid except for some provinces. The contents of organic matter was higher than the appropriate level(25 ~ 30 g·kg^-1) except for Gyeongsangbuk-do, the effective phosphoric acid was higher than the appropriate level(80~120 mg·kg^-1) in all provinces, and the effective silicic acid was lower than the appropriate level(157 ~ 180 mg·kg^-1) except for Gyeonggi-do, Jeollanam-do and Gyeongsangnam-do. As a result of analyzing the recommended fertilization amount based on the nitrogen application amount of 7 kg·10a^-1, 68.3% ofthe 240 samples were able to give nitrogen fertilizer less than 7.5 kg·10a^-1, and the rest had to be given more than that to satisfy the standard fertilization amount. As a result of this study, 68.3% of rice paddies nationwide can be cultivated with a standard fertilization amount of 7 kg·10a^-1, however it was thought that continuous nutrient management would be required for other paddies.

• Korean Journal of Food Science and Technology
• /
• v.26 no.5
• /
• pp.561-566
• /
• 1994

The kinds of kochujang were discriminated by using their organic acid compositions, GC peak areas of volatile concentrates and flavor intensity determined by sensory evaluation. Tested kochujang were 51 kinds of traditional kochujang and 10 kinds of industry-produced kochujang in the market. The traditional kochujang included 20 kinds of Sunchang kochujang prepared with glutinous rice, 11 kinds of Boeun kochujang prepared with barley and 20 kinds of Sachun kochujang prepared with wheat. Boeun kochujang was distinguished from other kinds of traditional and industry-produced kochujang by using canonical discriminant analysis for the compositions of organic acids. Among organic acids, lactic acid was the most contributing variable for the discrimination of various kochujang. Traditional and industry-produced kochujang could be classified into 4 groups by using discriminant analysis for GC peak areas. The peak number 2, 4, 8 and 11 were found to be highly contributing variables for the discrimination of kochujang by using stepwise discriminant analysis. Industry-produced kochujang was discriminated from traditional kochujang by using canonical discriminant analysis for the intensity of 8 kinds of flavor property. The taste 'umami' was found to be the most contributing variable for the discrimination of kochujang.

• Ocean Science Journal
• /
• v.40 no.3
• /
• pp.145-153
• /
• 2005

Variation in the microbial biomass and community structure found in sediment of heavily polluted bays and the adjacent unpolluted areas were examined using phospholipid fatty acid analysis. Total microbial biomass and microbial community structure were responding to environmental determinants, sediment grain size, depth of sediment, and pollution due to petroleum hydrocarbons. The marker fatty acids of microeukaryotes and prokaryotes - aerobic, anaerobic, and sulfate-reducing bacteria - were detected in sediments of the areas studied. Analysis of the fatty acid profiles revealed wide variations in the community structure in sediments, depending on the extent of pollution, sediment depth, and sediment grain size. The abundance of specific bacterial fatty acids points to the dominance of prokaryotic organisms, whose composition differed among the stations. Fatty acid distributions in sediments suggest the high contribution of aerobic bacteria. Sediments of polluted sites were significantly enriched with anaerobic bacteria in comparison with clean areas. The contribution of this bacterial group increased with the depth of sediments. Anaerobic bacteria were predominantly present in muddy sediments, as evidenced from the fatty acid profiles. Relatively high concentrations of marker fatty acids of sulfate-reducing bacteria were associated with organic pollution in this site. Specific fatty acids of microeukaryotes were more abundant in surface sediments than in deeper sediment layers. Among the microeukaryotes, diatoms were an important component. Significant amounts of bacterial biomass, the predominance of bacterial biomarker fatty acids with abundance of anaerobic and sulfate-reducing bacteria are indicative of a prokaryotic consortium responsive to organic pollution.

• Macromolecular Research
• /
• v.17 no.11
• /
• pp.912-918
• /
• 2009

An optically active diacid containing the L-histidine moiety was prepared by reacting pyromellitic dianhydride (1,2,4,5-benzenetetracarboxylic acid 1,2,4,5-dianhydride) 1 with L-histidine 2 in acetic acid, and was polymerized with several aromatic diamines 5a-g to obtain a new series of optically active poly(amide-imide)s (PAIs) using two different methods, such as direct polycondensation in a medium consisting of N-methyl-2-pyrrolidone (NMP)/triphenyl phosphite (TPP)/calcium chloride ($CaCl_2$)/pyridine (Py) and direct polycondensation in a tosyl chloride (TsCl)/pyridine (Py)/N,N-dimethylformamide (DMF) system as a condensation agent. The resulting new polymers 6a-g with inherent viscosity was obtained in good yield. The polymers were readily soluble in polar organic solvents, such as N,N-dimethyacetamide (DMAc), N,N-dimethyformamide (DMF), and dimethyl sulfoxide (DMSO). The obtained polymers were characterized by FTIR, specific rotation, elemental analysis as well as $^1$H-NMR spectroscopy and gel permeation chromatography (GPC). The thermal stability of the resulting PAIs was evaluated with thermogravimetric analysis techniques under a nitrogen atmosphere.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2000.06a
• /
• pp.99-105
• /
• 2000

Greases composed of base oil and thickener are widely used in the purpose of lubrication and anti-corrosion of machinery. However, greases are sometimes oxidized and decomposed by heat of friction, and produced organic acid. And the greases leaked out ordinary spot make the concrete structures weaken. In this study, the chemical effects of the greases with the concrete structures were investigated through oxidation reaction under pressure and oxygen, and evaluated by the analysis of TAN, Ca content, FT-IR and XRD of grease and cement powder after the oxidation reaction. As the results, TAN value decreased with the increase of the content of cement because of neutralization of organic acid produced by the oxidation of grease with calcium contained in the cement. The content of calcium linearly increased with the increase of cement due to calcium salt by neutralization of acid. Also, according to XRD results of the cement powder oxidized at 99 $^{\circ}C$, the diffraction peak due to calcium hydroxide decreased in comparison with that at room temperature because of the reaction of calcium and organic acid.

• KSBB Journal
• /
• v.15 no.1
• /
• pp.60-65
• /
• 2000

In order to predict the chromatogram for organic acid in ion chromatography, Langmuir isotherm parameters were obtained by Retention Time Method (RTM) and moment method. Ion chromatography analysis for formic acid was performed and compared with theoretically predicted profiles under isocratic condition. Band profiles were estimated with the equilibrium-dispersive model of chromatography using a PDEsolver Macsyma . The relationship between the characteristics of chromatogram and the variable operating condition in chromatography such as the flow rate, ionic strength and injection volume was studied. Satisfactory agreement was observed between the experimental and the estimated chromatograms with parameters obtained form the moment method.