• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.622-626
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• 1991

Antioxygenic effects of browning reaction product(BRP) obtained from 2M L-ascorbic acid(AsA) solution by heating at $85^{\circ}C$ were investigated. BRP obtained from AsA solution(pH 2.30) without pH adjusting showed slightly antioxygenic effect. As heating time increased, powers of antioxygenic activity of BRP did not increase. Retained AsA after heating did not effect antioxygenic activity of AsA solution. After adjusting pH of AsA solution to 2.3, 4.0, 7.0, 9.0 and 11.5 respectively, BRP were obtained from these AsA solution by heating at $85^{\circ}C$ for 15 hrs. Among these BRPs, BRPs of pH 2.3 and 4.0 showed no antioxygenic effect, lower browning degree and higher retained AsA, but had stronger reducing power. While those of pH 7.0, 9.0 and 11.5 had stronger antioxygenic activity, higher browing degree and lower retained AsA, but showed weaker reducing power. After adjusting pH of AsA solution to 7.0, antioxygenic activities of BRP which was obtained from this AsA solution by heating respectively at $85^{\circ}C$ for 0, 3, 5, 10, 15 and 25 hrs increased in proportion to heating time.

• Food Science and Preservation
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• v.16 no.5
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• pp.636-643
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• 2009

Inactivation by UV-C irradiation of Escherichia coli O157:H7 and Listeria monocytogenes inoculated onto washed carrots was examined. Carrot samples were inoculated with 6-7 log CFU/mL of E. coli O157:H7 or L. monocytogenes, treated with doses of 0, 1, 3, 5, or $10\;kJ/m^2$ UV-C, and stored at $4{\pm}1^{\circ}C$ for 8 d. The populations of E. coli O157:H7 and L. monocytogenes significantly decreased with increasing irradiation dose (p<0.05). In particular, E. coli O157:H7 and L. monocytogenes populations fell significantly by 2.35 and 2.38 log CFU/g at $10\;kJ/m^2$, respectively, compared to control values. UV-C irradiation inhibited color changes and decreased the whiteness index in carrot during storage, compared to controls. Sensory evaluation results showed that UV-C-treated carrots had better sensory characteristics than did the control. Therefore, the results suggest that UV-C irradiation could be useful to improve the microbial safety and sensory qualities of fresh-cut carrots during storage.

• Korean Journal of Plant Resources
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• v.16 no.3
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• pp.187-193
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• 2003

To determine the properties for juice preperation of Black Omija (Schizandra nigra Max.) and Omija (Schizandra chinensis), yield of extraction, chromaticity and lightness, pH and soluble solid of the extract were investigated. The rate of extract yield from Schizandra nigra was highest when extracted for 3 hours at 80$^{\circ}C$ in 20％ ethanol solution. For the desirable chromaticity coordinates, the optimum extraction time and temperature of Schizandra nigra extract were 3 hours at 80$^{\circ}C$. The lightness of the extract was low of the value when extraction time and temperature was long and high. The sugar content of the extract of S. nigra was 2.0­2.6％ Brix, lower than that of S. chinensis, but the difference was insignificant. The pH of the extract from S. nigra was 0.1­0.2 higher than that of S. chinensis. Although the pH of the extract from S. nigra was a little low when extracted by water, the pH range was enough to maintain the stability of color of extract from the S. chinensis.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.1
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• pp.29-36
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• 2019

This study investigated the self-healing properties of blast furnace slag cement paste sample with $Na_2SO_4$ as a blast furnace slag activator after conducting the permeability test. Self-healing properties were examined by crack filling ratio and quantification of self-healing products. The degree of self-healing was evaluated by the crack filling ratio, and the crack filling ratio was analyzed by panoramic analysis using BSE-DIP for objectivity. The average crack filling ratio showed a tendency of decreasing from the upper part of the specimen to the lower part as the average of the top part was 18%, the middle part was 7% and the bottom part was 5% on average. The maximum crack filling ratio was 44% and the minimum crack filling ratio was 3%. The residual self-healing product after the permeability test contained a large amount of Ca element and Al element derived from the blast furnace slag, and the Si element was mainly present near the crack surface. The most abundant minerals in self-healing products were about 68% C-A-H. $CaCO_3$ was about 13% and C-A-S-H was about 8%. Three minerals accounted for 90% of self-healing products. C-A-H was mainly present at a part slightly distant from the crack surface and showed an angular or acicular shape. The C-A-S-H was generated on the surface naturally connected to the existing specimen, and the $CaCO_3$ was generally observed on the surface of the specimen or the inside of the crack.

• Journal of the Korean Chemical Society
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• v.17 no.3
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• pp.169-173
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• 1973

The tridentate schiff base ligand, salicyliden amino-o-hydroxy benzene, has derived from salicylaldehyde and o-amino phenol. This ligand reacts with a series of Mo (VI), Mo (V), Mo (IV), and Mo (III) oxidated states and forms a new complexes; [Mo O$_2(H_2O)\;(C_{13}H_9O_2N)]$, [MoO Cl$(H_2O)\;(C_{13}H_9O_2N)]$, [Mo(SCN)$_2(H_2O)\;(C_{13}H_9O2_N)]$ 및 $[Mo(H_2O)_2\;(C_{13}H_9O_2N)]_2O$. The Mo (VI), Mo(V) and Mo(Ⅳ) ions in these complexes are octahedron, hexa coordinate, and the mole ratio of these ions to the ligand are 1 : 1, but Mo (III) Complex is a Mo-O-Mo oxygen bridge bond and polynuclear, and the mole ratio of Mo (III) to the ligand 1 : 1 above facts are identified from the data of Infrared spectra, visible spectra, and elemental analysis.

• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.671-679
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• 2010

The geometrical parameters and binding energies of the benzene ion-water complex [$C_6H_6^+-(H_2O)_n$(n=1-5)] have been investigated using ab initio (MP2) and density functional theory (DFT) with large basis sets. The harmonic vibrational frequencies and IR intensities are also determined to confirm that all the optimized geometries are true minima. Also zero-point vibrational energies have been considered to predict the binding energies. The predicted binding energy of 8.6 kcal/mol for $C_6H_6^+-(H_2O)$ at the MP2/aug-cc-pVTZ level of theory is in excellent agreement with recent experimental result of $8.5{\pm}1$ kcal/mol.

• Korean Journal of Microbiology
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• v.30 no.4
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• pp.239-245
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• 1992

Buci1llr.s 11c~h~n~1rnSiSi.As 3-2MI which is responsible for the special taste of traditionalKorean soy sause produced two kinds of proteinase. The activity of the proteinasc I washigher about two fold than that of proteinase 11. The optimai, reaction pH of proteinaseI and I1 wcre found to be 7-1 1.5 and 7-9. respectively. Proteinase I1 was more stable andactive than proteinase I at pH ranges around 3 to 5. The optimal te~tlperature of proteinaseI and I1 were 502. The temperature stabilitl of proteinase I1 was Inore stable thanproteinase 1 at temperature range around 30-quot;~A. ctivities of proteinase I and I1 graduallydeclined above $30^{\circ}$C and 45C. respectively. Proteinasc 1 was more active than proteinaseI1 at salt concentration range around 25-3500. The K,,, values of casein and soy proteinfor proteinase I were 6.89 mglml and 3.98 mglml. In case of proteinase 11. they were 9.00mgiml anti 11.44 111g/ml. respectively. The activity of the crudc enzyme was increased by1 rnM Pb(CH3COO). but was decreased by 5 n1M and 10 rnM of HgS04 and ZnS04. Thetwo proteinases produced amino acids and peptides from the soybean protein. The peptideswere digested into amino acids. Both protcinases were found to be the main enzymes thatproduced amino acids which make the main taste of traditional Korean soy sauce.al Korean soy sauce.

• Journal of Life Science
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• v.10 no.3
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• pp.300-306
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• 2000

Several bacterial strains utilizing crude oil as their sole carbon and energy source were isolated from polluted marine by crude oil. One of the strains, named KCL-2 showed strong degradation activity for crude oil. This strain was identified as a Klebsiella sp. based on the morphological, biochemical, and physiological characteristics. The optimum cultural conditions were as follows; $27^{\circ}C$~$37^{\circ}C$ for temperature and 7.0 for initial pH. Additionally, the optimal concentration of sodium chloride was 3.0%, confirming indicating that this strain was derived from sea water.The strain KCL-2 could use several kinds of n-alkane hydrocarbones from octadecane to octacosane as a sole carbon source. The emulsifying activity by KCL-2 was the highest after 3 days of cultivation under the condition of 3.0% sodium chloride, pH 7.0 and 32$^{\circ}C$. This strain had several criptic plasmids.

• Journal of Magnetics
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• v.7 no.2
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• pp.29-39
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• 2002

The initial NiCuZn synthetic ferrite were acquired from thermally decomposing the metal nitrates $Fe(NO_3)_39H_2O, Zn(NO_3)_26H_2O, Ni(NO_3)_26H_2O, and Cu(NO_3)_23H_2O$ at $150^circ{C}$ for 24 hours, and then we calcined the synthetic powder at $500^circ{C}$, pulverized each of those for 3, 6, 9, 12, and 15 hours in a steel ball mill, sintered each at $700^circ{C}$ to $1,000^circ{C}$ for 1 hour, and thus studied their microstructures and electromagnetic properties. We could make the initial specimens chemically bonded in liquidity at a low-temperature $150^circ{C}$, by using the low melting points less than $200^circ{C}$ of the metal nitrates instead of the mechanical ball-mill pulverization, then narrow a distance between the particles into a molecular one, and thus lower the reaction point of sintering by at least $200^circ{C}$ to $300^circ{C}$. Their initial permeability was 50 to 400 and their maximum magnetic induction density and coercive force, 2,400 G and 0.3 Oe to 0.5 Oe respectively, which was similar to those of NiZnCu ferrite synthesized in the conventional process. In the graph of initial permeability by frequencies, a $180^circ{C}$ rotation of the magnetic domains which appears in a broad band of micro-wave before and after the resonance frequency, could be perceived.

• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.31-31
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• 2002

The hydrothermal reaction of Zn(NO₃)₂6H₂O with benzene-1,3-dicarboxylic acid (or isophthalic acid, 1,3-BDCH₂) and pyridine led to the formation of a 1-dimensional coordination polymer with the empirical formula of [Zn₄(1,3-BDC)₃(Py)₂(O/sup 2-/)] (1). On the other hand, the hydrothermal reaction of Tb(NO₃)₃5H₂O with benzene-1,3-dicarboxylic acid (or isophthalic acid, 1,3-BDCH₂) and pyridine gave a 3-D compound [Tb₃(1,3-BDC)₂(H₂O₃] (2). The structures of both compounds have been determined by X-ray diffraction. 1 crystallizes in the monoclinlc space group P2₁/n, a = 10.344(3) Å, b = 18.030(3) Å, c = 18.033(3) Å, = 90.46(2)°, V = 3363.1(13) ,ų, Z = 4. 2 crystallizes in the monoclinic space group C2/n, a = 22.253(5) Å, b = 18.672(4) Å, c = 11.5812 Å, = 101.40(2)°, V = 4717.3(21) ų, Z = 8.