• YAKHAK HOEJI
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• v.38 no.1
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• pp.31-37
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• 1994

Active fraction, $P_2$, was Isolated from natural anti-cancer drug, $CP_2$, by HPLC. We confirmed that $P_2$ includes most of the Isoguanosine and minor components, Berberine and other protoberberine alkaloids, by $^1H-NMR$ and $^{13}C-NMR$ and measured tile cytotoxicity of $P_2$ against various tumor cell-lines.' $P_2$ was very effective to all tumor cell-lines, especially to human colon cancer SNU-C2A$(ED_{50};\;24{\mu}g)$ and liver cancer HEP-3B$(ED_{50};\;27{\mu}g)$.

• Polymer(Korea)
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• v.24 no.4
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• pp.445-452
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• 2000

The copolymerization of ethylene (E) and norbornene (N) was examined by using various metallocene catalysts and modified-MAO(MMAO) cocatalyst. For $C_2$-symmetry catalysts such as rac-Et(Ind)$_2$ZrC $l_2$, M $e_2$Si(Ind)$_2$ZrC $l_2$, M $e_2$Si(Cp)$_2$ZrC $l_2$ and Cs-symmetrical iPr(FluCp)ZrC $l_2$ as well as CGC and di-bridged zirconocene, the effects of catalyst structure and [N]/[E] feed ratio on catalyst activity, thermal property and [N] content of copolymer (COC) was investigated. For rac-Et(Ind)$_2$ZrC $l_2$ catalyst of a constant [N]/[E] feed ratio, the appropriate conditions of [Al]/[Zr] mole ratio, polymerization temperature and cocatalyst structure were found to be 3000, 4$0^{\circ}C$, MMAO cocatalyst, respectively. As [N]/[E] feed ratio increased, the incorporation of norbornene to copolymer increased while, the activity of catalyst decreased except for iPr(FluCp)ZrC $l_2$ With consideration of catalyst activity as well as N content, it was found that rac-Et(Ind)$_2$ZrC $l_2$/MMAO system exhibited relatively high activity and controllable $T_{g}$. Monomer reactivity ratio was determined by Kelen-Tudos method..

• Korean Journal of Crystallography
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• v.18 no.1_2
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• pp.1-6
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• 2007

An Organometallic compound, $C_{16}H_{35}B_{10}IrS_2Si$, was synthesized from o-carborane, $Cp^*Ir(S_2C_2B{10}H_{10})$, and $Me_3SiCHN_2$. The molecular structure of this complex has been determined by X-ray diffraction. Crystallographic data : monoclinic, space group $P2_1/n$, $a=10.1986(12)\;{\AA}$, $b=14.834(5)\;{\AA}$, $c=17.139\;{\AA}$, ${\beta}=92.24(2)^{\circ}$, Z=4, $V=2591.0(14)\;{\AA}^3$. The structure was solved by direct methods and refined by full-matrix leat-squares methods to give a model with a reliability factor R=0.053 for 5080 reflections.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.179-185
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• 2000

In this study, we examined the movement of chlorophenol as a precursor of the dioxin in the after-combustion to minimize the creation and emission of dioxin in a municipal waste incinerator. The CPs was injected to the electric incinerator in temperature $300{\sim}500^{\circ}C$, using $N_2$ gas to control the reaction time, The oxygen quantity supplied into the $CP_s's$ isomer combustion was added with the value of experience formula. When the space velocity in reactor was 60~80/sec, the removal efficiency of CP was obtained in the presence of Mo-V catalyst and non catalyst. The efficiency in non-catalyst was 74% to 80% mono-CP, di-CP 55~66%, tri-CP 50~58%, while mono-CP 90~99.9%, di-CP 96~97%, tri-CP 76~99% in a catalyst. Consequently, it was shown that these were 20~30% more efficienct than those.

• International Journal of Ocean System Engineering
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• v.3 no.2
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• pp.90-94
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• 2013

This study represents the recent laboratory results from cathodic protection (CP) system with the use of sacrificial anodes at different environmental conditions (temperature of $10^{\circ}C$ and $40^{\circ}C$). Specimens were slab type with a dimension of $500mm{\times}50mm{\times}100mm$, and concrete cover thickness were 25mm. Zinc mesh and/or bulk type anodes were installed at the center of specimen to confirm the distance that CP system has influences on the specimen to distribute uniform CP current to rebar. Two different kinds of temperature condition were applied to verify the effect of temperature. Experiments were conducted for 60 days, and the distribution of potential and current that supplied from anode to rebar was measured. From the results, CP potential was varied with time, and temperature played an important role in CP potential variations. Current was also changed with time, and current distribution could be improved by installing additional bulk type anode.

• Applied Biological Chemistry
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• v.49 no.1
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• pp.60-64
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• 2006

The effect of far-infrared (FIR) irradiation and heat treatment on the antioxidant activity of extracts from citrus pomaces (CP) was evaluated. CP were placed in pyrex petri dishes (8.0 cm diameter) and irradiated at $100^{\circ}C$ and $150^{\circ}C$ for 5, 10, 15, 20, 40 or 60 min with a FIR heater or simple heater, respectively. After FIR irradiation or simple heat treatment, 70% ethanol extracts (EE) and water extracts (WE) of CP were prepared and radical scavenging activity (RSA) and reducing power of the extracts were determined. The antioxidant activities of the extracts increased as the time of heating or FIR-irradiation increased. When CP were FIR-irradiated at $100^{\circ}C$ far 30min, the values of RSA and reducing power of EE increased from 14.9% to 44.2%, and 0.290 to 0.886, respectively, compared to the untreated control. Simple heat treatment of CP at $100^{\circ}C$ for 60 min also increased RSA and reducing power of EE to 44.7%, and 1.045, respectively. FIR irradiation and heat treatment increased RSA and reducing power of WE from CP, too. These results indicated the antioxidant activity of CP extracts was significantly affected by FIR irradiation and heating temperature and duration on CP, and that the FIR irradiation and heat treatment process can be used as a tool for increasing the antioxidant activity of CP.

• Journal of the Mineralogical Society of Korea
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• v.16 no.4
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• pp.295-305
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• 2003

This study aims to provide the physicochemical properties of three kinds of organo­smectites which can be diversely used in industries. Some properties of them were compared with Na­smectite. Three kinds of organo­smectites such as Hexadecyltrimethylammonium(HDTMA), Benzyldimethyltetradecylammonium(BDTDA), and Cetylpyridinium(CP) exchanged smectites were manufactured for this study. Three types of organo­smectites showed the alkaline character(pH 9), very low swelling property and viscosity, and a fast flocculation behavior because of strong hydrophobic property in contrast to hydrophilic Na­smectite. Three organo­smectites showed the strong interlayer expansion with basal spacing from $19\AA$ to $23\AA$ compared with the Na­smectite of about 12 $\AA$. Organic cations such as HDTMA, BDTDA, and CP exchanged into smectite were completely decomposed in the temperature range from $250^{\circ}C$ to $400^{\circ}C$. Generally, three organo­smectites showed the similar mineralogical, physicochemical and thermal properties. But their properties are quite different from Na­smectite. Considering economically, CP exchanged smectite would be used for the diverse utilization field in the future time.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.375-380
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• 2007

This study was conducted to develop herbicide-resistance domestic maize plants by introducing the CP4 5-enol-pyruvylshikimate-3-phosphate synthase (CP4 EPSPS) gene using Agrobacterium tumefaciens-mediated immature embryo transformation. Immature embryos of five genotypes (HW1, KL103, HW3, HW4, HW7) were co-cultivated with strains Agrobacterium tumefaciens (strain C58C1) containing the binary vector (pCAMBIA2300) carrying Ubiquitin promoter-CP4 EPSPS gene and Cauliflower mosaic virus 35S (CaMV35S) promoter-nptll gene conferring resistance to paromomycin as a selective agent. The presence and expression of CP4 EPSPS transgene were confirmed by PCR, RT-PCR and Northern blot analysis, respectively. Also, the resistance to glyphosate in the transgenic maize ($T_1$) was analyzed by shikimate accumulation assay. The frequency (%) of paromomycin-resistance callus was 0.37, 0.03, 2.20, 2.37, and 0.81% in pure lines HW1, KL103, HW3, HW4 and HW7, respectively. EPSP transgene sequences were amplified in putative transgenic plants that regenerated from paromomycin-resistance calli of two inbred lines (HW3, HW4). Of them, RT-PCR and Northern blot analyses revealed that the transgene was only expressed in two transgenic events (M266, M104) of HW4 inbred line, and a mild glyphosate resistance of transgenic event (M266) was confirmed by the lower shikimate accumulation in leaf segments. These results demonstrate that transgenic maize with herbicide-resistance traits in Korean genotype can be genetically obtained.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.2
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• pp.62-67
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• 2008

An Organometallic compound, $C_{12}H_{20}B_{10}S_2Co_2$, was synthesized from o-carborane, $Cp^*Co(S_2B_2B_{10}H_{10})$ and $BH_3{\cdot}THF$. The molecular structure of this complex has been determined by X-ray diffraction. Crystallographic data: monoclinic, space group Cc, a=15.981(4) ${\AA}$, b=15.478(17) ${\AA}$, c=12.0562(17) ${\AA}$, ${\beta}=115.063(16)^{\circ}$, Z=4, V=9683(4) ${\AA}^3$. The structure was solved by direct methods and refined by full-matrix leat-squares methods to give a model with a reliability factor R = 0.0630 for 9948 reflections.

• Journal of Korea Foundry Society
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• v.13 no.6
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• pp.524-531
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• 1993

Dispersion behaviors of SiC particles and microstructures in Al-2%Si/SiCp composite prepared by Rheo-compocasting were studied with change of fabrication conditions(slurry temperature, agitation time) and additions of Mg($0{\sim}3wt.%$). Also, the microhardness change of matrix, interface and total in composites were examined with additions of Mg($0{\sim}3wt.%$). The dispersion of particles in the composites became relatively homogeneous with increase of Mg additions, agitation time and decrease of slurry temperature. Rate of occupied area by particle in matrix was increased as increase of Mg additions due to improvement of wettability between SiC particle and matrix. A favorable composites were obtained by melting under Ar atmospheric SiCp injection and bottom pouring system. According to the analysis of X-ray diffraction, $Mg_2Si$, $Al_4C_3$, $SiO_2$ and MgO, etc, intermetallic compounds were formed by chemical interreaction at interface of matrix and particles. The microhardness of interface is higher than that of matrix due to more strengthening of above intermetallic compounds. It was considered that the total hardness of the composites is improved by dispersing of SiCp and addition of Mg.