• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.2
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• pp.173-178
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• 2006

Anthocyanin in blackish purple rice is composed of cyanidin, peonidin, malvidin, pelargonidin and delphinidin flavylium ion and their glucosides, which shows antioxidant activity similar to a-tocoperol. It has been demonstrated that cyanidin-3-glucoside(C3G) of anthocyanin has a high-potency antioxidant activity, and is a prominent in anticancer and antithrombotic activity. In analysis of content of anthocyanin from the genetic source of blackish purple rice, the level of C3G was approximately 80% of total contents of anthocyanins, and showed the highest content in Heugjinjubyeo, of which contains an amount of 500 mg by weight of 100g brown rice in comparison that most of varieties has less than 50mg by weight of 100g brown rice. We found that C3G pigment in blackish purple rice was considerably affected by cultural season, cultivation area, ripening temperature, and weather condition, etc. as well as genetic properties. In cross combination between Heugjinjubyeo and Suwon425, intermediate parent $F_9$ generation which was three times higher or more in C3G content than that of Heugjinjubyeo was bred, of which it contained an amount of 1678 mg by weight of 100g brown rice, and we called it 'C3GHi' Rice. And, we found that the C3GHi rice was more excellent than that of the existing Heugjinjubyeo in anticancer and antithrombotic activity. Methanol extract from Heugjinjubyeo was fractionated by organic solvents in order of n-hexane, $CH_{2}Cl_2$ and n-BuOH, and then oryzafuran, quercetin, vanillic acid and protocatechuic acid and their structures from the n-BuOH fraction were ascertained. Oryzafuran of these compounds was a natural compound found firstly in nature. Quercetin and protocatechuic acid besides new compound oryzafuran showed excellent antioxidant ability to vitamin C. These results suggest that blackish purple rice has very high value as a source of various functional food as well as staple food.

• Journal of Surface Science and Engineering
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• v.30 no.3
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• pp.159-166
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• 1997

The metalliding technique was adopted to obtain the diffusion coating of zirconium on AISI 304 Stainless Steel in molten mixed chlorides (32.9wt.%LICl-34.8wt.%NaCl-32.3wt.%). Experiments were carried out in argon gas atmosphere. The electrolytic cell was consisted of a AISI 304 Stainless steel cathode and a consumable zirconium anode. The quality of deposit was analysed by SEM, Optical Microscope, EDS, and also examined by the Micro-Vickers hardness and corrosion tests. Interface of deposit layer was identified as zirconium-iron alloy layer caused by diffusion process at elevated temperatures. The optimum condition for the metalliding was found to be the bath temperature of $550^{\circ}C$, the concentration of $K_2ZrF_6$ ,5wt.%, cathodic current derrent density of 7.0 to 10.0mA/$\textrm{cm}^2$ , and anodic current density of 2.0mA/$\textrm{cm}^2$.

• KSBB Journal
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• v.18 no.2
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• pp.145-148
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• 2003

The hydrogen-producting bacterium was isolated from fresh water and identified as Enterbacter cloacae. The isolated was named Enterobacter cloacae YJ-1. In batch culture, The optimum cultivation temperature and pH of strain YJ-1 was 35$^{\circ}C$ and 7.5, respectively. All of the added glucose was consumed completely during fermentation even though pH was not controlled. Amount of hydrogen produced on each condition of 2% glucose, 4% sucrose and 5% fructose was 950, 1000 and 948 mL/L, respectively and resulted in increasing hydrogen production approximately 2.5-times more than controlled condition. The macimum hydrogen production was obtained when 50mM phosphate was added. was obtained when 50mM phosphate was added. In repeated0batch culture, yeast extract, but the production amount was not changed on the condition of over 0.5%, Most of the organic acides produced during the fermentation were formic and acetic acid, and propionic acid was moiety also generated.

• Bulletin of the Korean Chemical Society
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• v.15 no.3
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• pp.221-227
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• 1994

The barrier heights of the internal rotations for ethyl halides calculated by ab initio methods differ from those of experiments by more than 0.2 kcal/mol. The use of basis sets larger than the $6-31G^{\ast}$ set and the inclusion of correlation do not improve the agreement between the calculated and experimental values. The zero-point vibration corrections are substantial in the HF calculations with $6-31G^{\ast}$ basis sets, but become negligible in the MP2 calculations with $6-311G^{{\ast}{\ast}}$ basis sets for $C_2H_5F\;and\;C_2H_5Cl$. It is shown that the rigid rotor approximation and the assumed shape of the potential curve as a cos2${\theta}$ curve could also be the sources of discrepancies between calculated and experimental values. Higher order perturbation corrections narrow the gap between experimental and theoretical values, but there still remains about 10% overestimate of 0.3 kcal/mol. Optimized geometries from the HF and MP2 calculations are in good agreement with those from experiments. Dipole moments calculated from the MP2 densities show slightly better agreement with experiments than those from the HF densities.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.174-177
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• 1991

Fluorine-doped $SnO_2\;(SnO_2:F)$ films were prepared in ordinary atmosphere on borosilicate glass substrates using pyrosol deposition method starting from the solutions composed of $SnCl_4-5H_2O-NH_4F-CH_3OH-H_2O-HCl$ in an attempt to develop transparent conductors for use in amorphous silicon (a-Si) solar cello. The deposition rate of films increased with the increase in the content of $H_2O$, whereas it decreased with increasing the content of $CH_3OH$. When air was used as the carrier gas, the lowest electrical resistivity was obtained from a solution having $CH_3OH/H_2O$ mol ratio of about $2{\sim}3$ in the solution. The use of $N_2$ of the same flow rate as the carrier gab resulted always in the high resistive films, but the resistivity of the films decreased continuously with the increase in the content of $H_2O$. The surface morphology and preferred orientation of films were also affected by the solvent composition and the content of HCl in the solution. The room-temperature resistance of the films were fairly stable after heat-treatments up to $600^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.964-969
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• 1995

For the effective utilization of cellulosic biomass, conidial protoplast fusion between Aspergillus niger MAN-831(${\beta}-glucosidase$) and A. wentii MAW-538(CMCase and avicelase), which produced potently cellulolytic enzymes was carried out. Optimal conditions for formation and regeneration of protoplast were conidiospore age-5 dyuas. $2-DG-30\mu\textrm{g}/ml$, preincubation time-4 hours, osmotic stabilizer-0.7M KCl, novozyme(7mg/ml)＋driselase(2.5mg/ml) and reaction time of enzyme-5 hours. Optimal conditions for protoplast fusion were obtained by treatment of protoplasts with 15mM CaCl2 and 25% polyethylene glycol 4000(pH 6~7) as fusogenic agent at $36^{\circ}C$ for 25~30 minutes. The frequency was then $7.94{\times}10^{-4}$. CMCase, avicelase and ${\beta}-glucosidase$ activity of fusant F-208 strain was 1.5, 1.3, 1.2 times higher than those of parental strains, respectively.

• Bulletin of the Korean Chemical Society
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• v.28 no.8
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• pp.1363-1370
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• 2007

The geometrical structures of pyridazin-3-one derivatives (4,5-dihalopyridazin-3-one and 4-halo-5- alkoxypyridazin-3-one) with various functional and substituent groups were fully optimized using the ab initio Hartree-Fock (HF) and second order Moller-Plesset perturbation (MP2) methods. At the N2-, C4-, and C5- positions on the pyridazin-3-one rings, the structural and electronic features pertaining to the variations of the functional and substituent groups were analyzed, respectively. The trends in the variation of the bond lengths, atomic charges, and energetics (relative energy, binding energy) of the derivatives induced by changing the electron donating functional groups (X1 = OMe, OEt) to electron withdrawing groups (X1 = Cl, NO2) were examined. The variations of the bond lengths, atomic charges, and binding energies with the electron withdrawing strength of the substituent groups (Y = Me → F) were also investigated.

• ETRI Journal
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• v.16 no.1
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• pp.45-57
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• 1994

The effects of reactive ion etching (RIE) of $SiO_2$ layer in $CHF_3/C_2F_6$ on the underlying Si surface have been studied by X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometer, Rutherford backscattering spectroscopy, and high resolution transmission electron microscopy. We found that two distinguishable modified layers are formed by RIE : (i) a uniform residue surface layer of 4 nm thickness composed entirely of carbon, fluorine, oxygen, and hydrogen with 9 different kinds of chemical bonds and (ii) a contaminated silicon layer of about 50 nm thickness with carbon and fluorine atoms without any observable crystalline defects. To search the removal condition of the silicon surface residue, we monitored the changes of surface compositions for the etched silicon after various post treatments as rapid thermal anneal, $O_2$, $NF_3$, $SF_6$, and $Cl_2$ plasma treatments. XPS analysis revealed that $NF_3$ treatment is most effective. With 10 seconds exposure to $NF_3$ plasma, the fluorocarbon residue film decomposes. The remained fluorine completely disappears after the following wet cleaning.

• Analytical Science and Technology
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• v.8 no.4
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• pp.649-654
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• 1995

The reactivity of superoxide ion($O{_2}^{-.}$) with halogenated substrates is investigated by cyclic voltammetry and rotated ring-disk electrode method in aprotic solvents. The more positive the reduction potential of the substituted nitrile, the more facile is nucleophilic displacement by $O{_2}^{-.}$. The reaction rates of halogenonitriles with $O{_2}^{-.}$ vary according to the leaving-group propensity of halide (Br>Cl>F). The relative reaction rates of other substituted nitriles are in the order of electron-withdrawing propensity of the substituent group (CN> $C(O)NH_2$ >Ph, $CH_2CN$). The reaction of $O{_2}^{-.}$ with dihalocarbons indicates that five-membered rings can be rapidly formed by the cyclization of substrate and $O{_2}^{-.}$, and the relative rates of cyclization depend on the number of methylenic carbons {$Br(CH_2)_nBr$, [n=1<2<3>4>5]}. Mechanisms are proposed for the reaction of $O{_2}^{-.}$ with halogenated substrates.

• Bulletin of the Korean Chemical Society
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• v.16 no.11
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• pp.1060-1064
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• 1995

The reactivity of superoxide ion (O2-.) with halogenated substrates is investigated by cyclic voltammetry and rotated ring-disk electrode method in aprotic solvents. The more positive the reduction potential of the substituted nitrile, the more facile is nucleophilic displacement by O2-.. The reaction rates of halogenonitriles with O2-. vary according to the leaving-group propensity of halide (Br > Cl > F). The relative reaction rates of other substituted nitriles are in the order of electron-withdrawing propensity of the substituent group (CN > C(O)NH2 > Ph ≒ CH2CN). The reaction of O2-. with dihalocarbons indicates that five-membered rings can be rapidly formed by the cyclization of substrate and O2-., and the relative rates of cyclization depend on the number of methylenic carbons {Br(CH2)nBr, [n=1 < 2 < 3 > 4 > 5]}. Mechanisms are proposed for the reaction of O2-. with halogenated substrates.