• Bulletin of the Korean Chemical Society
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• v.24 no.6
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• pp.853-858
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• 2003

The reaction mechanism of the pyrolysis of sulphonyl oximes ($CH_3-C_6H_4-S(O)_2O-N=C(H)-C_6H_4Y$), in the gas phase is studied theoretically at HF/3-21G, ONIOM (B3LYP/6-31G**:HF/3-21G) and ONIOM (MP2/6- 31G**:HF/3-21G) levels. All the calculations show that the thermal decomposition of sulphonyl oximes is a concerted asynchronous process via a six-membered cyclic transition state. The activation energies (Ea) predicted by ONIOM (B3LYP/6-31G**: HF/3-21G) method are in good agreement with the experimental results for a series of tosyl arenecarboxaldoximes. Five para substituents, Y = $OCH_3$, $CH_3$, H, Cl, and $NO_2$, are employed to investigate the substituent effect on the elimination reaction. Linear Hammett correlations are obtained in all calculations in contrast to the experimental finding.

• KSBB Journal
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• v.15 no.4
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• pp.370-374
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• 2000

Some bacterial strains isolated from activated sludges and media and type cultures were cultivated in a pharmaceutical wastewater and a paperboard wastewater and added during batch treatment of those wastewaters in order for these strains to increase the treatment efficiency. Bacillus sp(PC-3) isolated from the charcoal media of the pharmaceutical wastewater plant grew remarkably over there strains in that wastewater and the viable cell count after 24hr cultivation was $1.1{\times}10^6m/L$. Bacillus subtills KCTC 1028 a type strain grew best in the paperboard wastewater and the viable cell count after 24hr cultivation was $1.1{\times}10^7m/L$. Addition of PC-3 in a batch treatment of the pharmaceutical wastewater increased COD removal by 18% after 8 day. And addition of Bacillus subtills KCTC 1028 in a batch treatment of the paperboard wastewater increased COD removal by 14% only after 24hy Bacillus subtills DCTC 1028 was though to be able to be produced economically using alcohol distillery wastewaters from starch material.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.2
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• pp.225-232
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• 1992

The purpose of this study was to compare the bond strength of the glass ionomer luting cements after the functional loads were applied to the crowns respectively 10 min, 30 min, 1 hr, 24 hrs later after mixing of cements. The conventional (GC Fuji I; GC Int. Co., Japan), water hardening type (Ketac Cem; ESPE, W. Germany) glass ionomer luting cement and C-dent ZPC (Confi-Dental Products Co., U.S.A.) as a control were used. The results of this study were obtained as follows: 1. In the bond strength of GC Fuji I, 24 hr-group was highest and there were no statistically significant differences among 10 min-, 30 min- and 1 hr- groups. 2. l3 the bond strength of Ketac Cem and C-dent ZPC, there was no statistically significant differences among 10 min-, 30 min-, 1 hr- and 24 hr-groups respectively. 3. Comparing the bond strength among cements in 10 min-, 30 min-groups respectively, GC Fuji I was lowest and there was no statistically significant difference between Ketac Cem and C-dent ZPC. 4. The bond strengths between GC Fuji I and Ketac Cem were not significantly different in 1 hr-, 24 hr-group. 5. The bond strengths among 3 types of cements were not significantly different in 24 hr-groups.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.67-76
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• 2016

This study was conducted to examine the optimal environmental condition for promoting the growth of sowthistle as affected by light quality and photoperiod in a closed-type plant production system. Seeds were sown in 240-cell plug trays and then germinated for 3 days at a 24-hour photoperiod in a closed-type plant production system with LED lights (R:B:W = 8:1:1). Seedlings were transplanted and grown under 3 types of LED (R:B:W = 8:1:1, R:W = 3:7, or R:B = 8:2) and 4 photoperiods (24/0, 16/8, 8/16, or 4/20 hours) with $230{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ light intensity at a density of $20cm{\times}20 cm$. The experimental design was a randomized complete block design. Plants were cultured for 40 days un der the condition of $21{\pm}2^{\circ}C$ and $70{\pm}10%$ relative humidity after transplanting. Plants were fed with a recycling nutrient solution (pH 7.0 and EC $2.0dS{\cdot}m^{-1}$) contained in a deep floating tank. Fresh weight and dry weight of shoot or root, leaf length, and leaf area were the greatest in the photoperiod of 24/0 (light/dark) with RW LED. The highest number of leaves occurred in the photoperiod of 16/8 (light/dark) with RB LED, while the incidence of tip burn was higher in the photoperiod of 24/0 (light/dark) compared to the other treatments. Chlorophyll value was the highest in the 16/8 (light/dark) photoperiod and there was no significant difference by light quality. Chlorophyll fluorescence was the lowest in the photoperiod of 24/0 (light/dark) compared with other treatments. Therefore, in terms of economic feasibility and productivity for Ixeris dentata Nakai cultivation in a closed-type plant production system, the results obtained suggest that plants grew the best when kept in a photoperiod of 16/8 (light/dark) and light quality of combined LED RW (3:7).

• Economic and Environmental Geology
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• v.43 no.3
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• pp.269-278
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• 2010

We investigated characteristics of the coloring material of Dancheong pigments and hope that this study contributes the revival of traditional Dancheong pigments color. For this purpose, we collected Dancheong fragment samples that fell off naturally from old wooden buildings in Gwangju and Jeonnam and analyzed the natural coloring material by XRD and EDS-SEM analysis method. In white pigments of Dancheong fragments, it is confirmed that gypsum$(CaSO_{4}{\cdot}2H_{2}O)$, quartz$(SiO_{2})$, white lead$(PbCO_{3})$ and calcite$(CaCO_{3})$ which have been used for white pigments since ancient times and $TiO_{2}$ which is common used in modern times. In red pigments of Dancheong fragments, it is confirmed that hematite$(Fe_{2}O_{3})$ and red lead$(Pb_{3}O_{4})$, which have been used for red pigments since ancient times and C.I. pigment orange $13(C_{32}H_{24}C_{12}N_{8}O_{2})$ but there is no cinnabar(HgS) which has been used since B.C. 3000 in China. In yellow pigments of Dancheong fragments, it is confirmed that crocoite$(PbCrO_{4})$ and massicot(PbO). In blue pigments of Dancheong fragments, it is confirmed that sodalite$(Na_{4}BeAlSi_{4}O_{12}Cl)$ and nosean $(Na_{8}Al_{6}Si_{6}O_{24}SO_{4})$ as coloring material of blue pigment and C.I. pigments blue $29(Na_{7}Al_{6}Si_{6}O_{24}S_{3})$ which is used in modern times. In green pigments of Dancheong fragments, it is confirmed that calumetite$(Cu(OHCI)_{2}{\cdot}2H_{2}O)$, escolaite(Cr2O3), dichromium trioxide$(Cr_{2}O_{3})$, emerald green$(C_{2}H_{3}As_{3}Cu_{2}O_{8})$, and C.I. pigments green$(C_{32}H_{16}-XCl_{x}Cu_{8})$ which is used in modern time. In black pigments of Dancheong fragments, Chiness ink(carbon black) is confirmed.

• Journal of Wetlands Research
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• v.3 no.2
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• pp.143-151
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• 2001

The community of phytoplankton, dominant species and environmental factor were investigated in Motjae-neup from January to September, 1996. A total 45 taxa were identified during the investigation period and composed of 5 classes, 8 orders, 13 families, 24 genera, 37 species, 6 varieties, 2 formation. The most important group was Chlorophyceae with 19(42.2%) taxa, followed by the Bacillariophyceae with 13(28.9%) taxa, Euglenophyceae with 7(15.6%) taxa, Cyanophyceae with 5(11.1%) taxa and Dinophyceae with 1(2.2%) taxon. Frustulia rhomboides, Eunotia lunaris, and Stauroneis anceps were important dominant species at Motjae-neup. The common species of all season are Microsystis aeruginosa, Melosira. varians, Frustulia rhomboides, Pinnularia braunii var. amphicephala, Stauroneis anceps. Ranges of environmental factors were measured : temperature, $3^{\circ}C{\sim}38^{\circ}C$; water temperature, $3.3^{\circ}C{\sim}26.5^{\circ}C$; pH, 5.7~6.38; BOD, $4.3{\sim}19.6mg/{\ell}$; chlorophyll a, $6.9mg/m^3{\sim}25.9mg/m^3$; SS, $26mg/{\ell}{\sim}52mg/{\ell}$; COD, $24{\sim}46mg/{\ell}$; total-N, $0.9538mg/{\ell}{\sim}2.3036mg/{\ell}$; total-P, $0.1057mg/{\ell}{\sim}0.1909mg/{\ell}$; electron conductivity, $25.5{\mu}s/m^3{\sim}2.3036{\mu}s/m^3$.

• Korean Journal of Microbiology
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• v.35 no.2
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• pp.146-152
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• 1999

Acceplor reaction of glucosyltr~ansferase of Streptococcus ,SO~~-~IZLIS with f ~ ~ t o ~ y l o l i g o ~ a ~ ~ h a r i d e ~ was studied for the biosynthesis of novel olgisaccharides. First, bacilracin resistant mutants were selected by mutagenesis of Streptococcus sobrimis ATCC27351. Among these mutants 4 strains were selected by resistance to bacitracin and increase of glucosyltransferase. Acceptor reaction of maltose was analyzed by TLC and image analysis. There were differences in the specificity of the acceptor reaclion by Ule glucosylumsferase between mother strain (Streptococcus sobrinus ATCC2735) and bacitracin resistant mutants (Streptococcus sobrinus BR24C, Strepfococcus sobrinus CH-5). Molher strain did ilot show an acceptor reaction with fructosyloligosaccharides such as 1-keqtose and nystose. Acceptor reaction products of turailose and 1-kestose with glucosyltransferase (GW-S) of Streptococcus sobrini~s BR24C were TEX>\6^{3}$-$\alpha$-D-glucopyranosyl \3^{2}$-O-$\alpha$-D-fructose (glucose-fructose-glucose) and \6^{4}$-$\alpha$-D-glucopyranosyl \1^{3}$-$\beta$-D-~-h~ctofuranos~~ sucrose (glucose-glucosefructose- fructose). respectively These are novel oligosaccharides which can be produced only by enzymatic reaction.

• Korean Journal of Environmental Biology
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• v.32 no.3
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• pp.225-233
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• 2014

In this study, we investigated the changes in the physiological and histological traits of a sea squirt (Halocynthia roretzi) with the emergence of the soft tunic syndrome induced by the water temperature control (6, 9, 12, 15, 18, 21, 24 and $27^{\circ}C$). It was observed that the induction rate of the soft tunic syndrome was highest at $15^{\circ}C$, but lowest at $24^{\circ}C$. Based on the tunic color condition and contraction strength, the whole process were classified into 4 stages as S0, S1, S2 and S3. Interestingly, there were significant differences in oxygen consumption and filtration rate were observed during S0-S3. The most distinctive aspects were change of blood cell composition at stage S3, whereas multi-vacuole cell ratio was decreased by 1/2 and morula cell ratio expanded about 10 times during S0-S3. Further, change of organ structure started following the syndrome such as degeneration of epithelial cells, microfilaments, increment in hemocytes and damage in muscle fiber have been detected in tunic, siphon, branchial sac, body wall musculature and pyloric gland. Briefly, our study results indicated that the normal physiological functions of the sea squirt can be affected due to the soft tunic syndrome induced by water temperature.

• Progress in Superconductivity and Cryogenics
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• v.24 no.4
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• pp.55-58
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• 2022

Carbon-based doping to MgB₂ superconductor is the simplest approach to enhance the critical current densities under magnetic fields. Carbon quantum dots is synthesized in this work as a carbon provider to MgB₂ superconductors. Polyvinyl Pyrrolidone is pyrolyzed and dispersed in dimethylfomamide solvent as a dopant to the mixture of Mg and B powders. Doped MgB₂ bulk samples clearly show the decrease of a-axis lattice constant, grain refinements, and broadening of FWHM of diffraction peaks compared to un-doped MgB₂ possibly due to the carbon substitution and/or boron vacancy at the boron site in MgB₂ lattice. Also, high-field J_c for the doped MgB₂ is enhanced significantly with the crossover about 3 T at 5 & 20 K when increasing the doping of carbon quantum dots.

• Progress in Superconductivity and Cryogenics
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• v.24 no.3
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• pp.52-56
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• 2022

Single-grain (c-normal or c-parallel) and multi-grain YBCO superconductors were prepared by a melt growth process with/without seeding. The magnetic levitation force and trapped magnetic field at liquid N₂ temperature (77 K) of the YBCO superconductors were investigated. Samples for the levitation force measurement were zero-field cooled (ZFC) to 77 K, and samples for trapped field measurement were field-cooled (FC) using Nd magnets. As for the magnetic levitation force, the c-normal, single grain sample showed the largest value, whereas the multi-grain sample showed the lowest value. The trapped magnetic field of the c-normal and c-parallel single-grain samples was 4-5 times that of the multi-grain sample. In addition, as the external magnetic field (the number of magnets) increased, the both properties increased proportionally. These results were explained in terms of the orientation dependence of the levitation forces and the magnetic field trapping capability of the YBCO superconductor.