• Journal of the Korean Ceramic Society
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• v.35 no.9
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• pp.953-957
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• 1998

The effects of catalysts and reactive conditions on the synthesis of aluminum alkoxides are investigated. HgCl2 and I2 as catalysts are used in the synthesis reaction for comparing to no addtion. The absorption peak in IR spectra according to Al-O-L bond of aluminum isopropoxide and aluminum sec-butoxide appear at near 1030cm-1 and 1060cm-1 respectively regardless of kinds of catalysts. The synthesis yield of alu-minum-isopropoxide was 90% in case of no catalyst addition and increased to all of 95% by addition of HgCl2 and I2 The synthesis yield of aluminum sec-butoxide is increased to 95% by addition of I2 catalyst com-paring to no addition.

• The Korean Journal of Ceramics
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• v.2 no.4
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• pp.221-225
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• 1996

In diamond synthesis by metal film growth method under high pressure and high temperature, the nucleation and growth of diamond was observed dependent on the carbon source variation from graphite powder to the heat treated powders of lamp black carbon. At the low driving force condition near equilibrium pressure and temperature line, nucleation of diamond did not occur but growth of seed diamond appeared in the synthesis from lamp black carbon while both nucleation and growth of diamond took place in the synthesis from graphite. Growth morphology change of diamond occurred from cubo-octahedron to octahedron in the synthesis from graphite but very irregular growth of seed diamond occurred in the synthesis from lamp block carbon. Lamp black carbon transformed to recrystallized graphite first and very nucleation of diamond was observed on the recrystallized graphite surface. Growth morphology of diamond on the recrystallized graphite was clear cubo-octahedron even at higher pressure departure condition from equilibrium pressure and temperature line.

• Environmental Mutagens and Carcinogens
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• v.11 no.2
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• pp.107-117
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• 1991

The effect of 3-aminobenzamide (3AB), an inhibitor of poly (ADP-ribose) polymerase, on ethyl methanesulfonate (EMS)-or bleomycin (BLM)-induced DNA repair synthesis and chromosome aberrations was examined during the cell cycle of Chinese hamster ovary (CHO)-K$_1$ cells. The synchronized cells were obtained by using thymidine double block method and mitotic selection method. Three assays were employed in this study: unscheduled DNA synthesis, alkaline elution and chromosome aberrations. 3AB alone did not induce DNA repair and chromosome aberrations in all phases. The post-treatment with 3AB inhibited DNA repair synthesis induced by EMS or BLM in G$_2$ phase, whereas 3AB did not affect chromosome aberrations induced by EMS or BLM in all phases. These results suggest that 3AB aggravates the cell cycle disturbance which occur after DNA damage, and leads to an accumulation of cells at G$_2$ phase, and inhibits DNA repair synthesis, while the effect 3AB on chromosome aberrations may need reevaluated.

• Toxicological Research
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• v.8 no.1
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• pp.9-15
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• 1992

Hydroxybrazilin was examined for its effects on glycogen synthesis in primary cultured rat hepatocytes. At 10-6 M hydroxybrazilin, glycogen synthesis was increased in basal state, but not in insulin stimulated state. However, any signiFicant changes were nor observed at 10-5 M hydroxybrazilin in both states. The glycogen synthesis was rather suppressed at 10-5M hydroxybrazilin. It was also observed that hydroxybrazilin increased insulin sensitivity but not insulin responsiveness at 10-5M concentration. These results suggest that hydroxybrazilin might exert hypoglycemic action through its effects on insulin receptor and post receptor events.

• Toxicological Research
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• v.32 no.2
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• pp.95-102
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• 2016

In the recent years, noble nanoparticles have attracted and emerged in the field of biology, medicine and electronics due to their incredible applications. There were several methods have been used for synthesis of nanoparticles such as toxic chemicals and high energy physical procedures. To overcome these, biological method has been used for the synthesis of various metal nanoparticles. Among the nanoparticles, silver nanoparticles (AgNPs) have received much attention in various fields, such as antimicrobial activity, therapeutics, bio-molecular detection, silver nanocoated medical devices and optical receptor. Moreover, the biological approach, in particular the usage of natural organisms has offered a reliable, simple, nontoxic and environmental friendly method. Hence, the current article is focused on the biological synthesis of silver nanoparticles and their application in the biomedical field.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06c
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• pp.147-150
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• 1998

In the case of speech synthesis, the waveform coding method with high quality is mainly used to the synthesis by analysis. Because the parameters of this coding method are not classified as both excitation and vocal tract parameters, it is difficult to apply the waveform coding method to the synthesis by rule. Thus, in order to apply the waveform coding method to the synthesis by rule, a pitch alteration is required for the prosody control. In the speech synthesis method by the conventional PSOLA technique, applying symmetric window function to asymmetric speech waveform, it occurs the unbalance phenomenon of energy according to the overlapped degree of pitch interval adjustment. In this paper to overcome the unbalance phenomenon of energy, we proposed a new method that can convert asymmetric waveform to symmetric one by time-frequency conversion. As a result, we can obtain an average spectrum distortion ratio with 6.38% according to the pitch alteration ratio.

• Journal of Plant Biology
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• v.23 no.3_4
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• pp.91-98
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• 1980

In the present study effects of 2,4-D and kinetin on the callus tissue growth of Korean ginseng(Panax ginseng C. A. Meyer), in relation to the synthesis of saponin were investigated. The saponin synthesis in the callus culture of ginseng root was enhanced by 2,4-D and kinetin. The total saponin content of callus grown on the optima growth conditions, that is, 5mg/l of 2,4-D and 2mg/l of kinetin, was about three times as high as that of the 6 year-old ginseng roots commercially used as herbs. The kinetin specifically increased the synthesis of protopanaxadiol group ginsenoside and decreased the syntehsis of protopanaxatriol gropu in callus cultures, while 2,4-D caused to an increase in the synthesis of protopanaxatriol group ginsenoside and decrease the synthesis of protopanaxadiol group.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.620-623
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• 2001

The peculiarities of using Self-propagating High-temperature Synthesis (SHS) and solid state phase synthesis for production of high temperature superconductor materials are discussed. Oxide superconductors with general formula $ReBa_2$$Cu_3$$O_{7-x}$ (Re= Y, Yb, Sm, Nd) have been made with using barium oxide initial powder instead of traditional barium carbonate. X-ray powder diffraction showed a single phase orthorhombic perovskite structure was produced in all reactions. Phenomena observed during the grinding of the reactant mixture are presented. Mechano-chemical activation - as a pretreatment of the reactant mixture - strongly influences the kinetic parameters, the reaction mechanism, and the composition and structure of the final product.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.2
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• pp.63-67
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• 2003

Synthesis of $PbLaTiO_{3}$ : Mn powders containing La and Mn was carried out using $PbO,\;TiO_{2},\;La_{2}O_{3}\;and\;MnO_{2}$ as starting materials by hydrothermal method. In the synthesis of single phase $PbLaTiO_{3}$ : Mn powder containing La and Mn, the optimal x value corresponding to La substitution was 0.01 which corresponds to $0.99(Pb_{1-x}La_{2x/3}TiO_{3})+0.01MnO_{2}$. The optimal conditions for the preparation of the powder synthesis were 8 M-KOH solvent of hydrothermal solvent, $270^{\circ}C$ of reaction temperature and 24 hrs of run time. It was found that the synthesized powders had spherical morphology with average particle size of 70 nm and specific surface area of $5.5\;m^{2}/g$.

• Journal of the HCI Society of Korea
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• v.6 no.1
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• pp.21-26
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• 2011

This paper presents a robust method for facial image synthesis under varying illumination by combining illumination correction and Poisson image processing techniques. The presented method automatically detects skin area and corrects highly saturated regions that can cause bad effects on the final synthesis image. The developed method can be applied to various facial synthesis applications by correcting illumination variations that can occur frequently on photos taken with a camera phone.