• Korean Journal of Crystallography
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• v.17 no.1
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• pp.10-13
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• 2006

The crystal structure of Ethylenediammonium chromate, $C_2H_{10}N_2{\cdot}CrO_4$, has been determined by X-ray crystallography. Crystal data: a=6.667(2), b=8.845(2), c:11.827(2) ${\AA}$, Orthorhombic, $P2_12_12_1$(Space Group No=19), Z=4, V=697.4(3) ${\AA}{^3},\;Dc=1.696gcm^{-3},\;{\mu}=1.594mm^{-1}$. The structure was solved by Patterson method and refined by full matrix least-square methods using unit weights. The final R and S values were $R_1=0.0254,\;R_w=0.070,\;R_{all}=0.0255$ and S=1.133 for the observed 1195 reflections. Bond length and angles of two ions are similar to the previously reported data. The ethylenediammonium ion has trans-configuration and are linked through many hydrogen bonds with neighboring anions.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.1
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• pp.11-21
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• 1999

For microelectronic packaging application, the crystallizable glass powder in CaO-$A1_2O_3-SiO_2-B_2O_3$system was mixed with various amounts of alumina inclusions (\approx 4 $\mu \textrm{m}$), and its sintering behavior, crystallization behavior, and dielectric constant were examined in terms of vol% of alumina and the reaction between the alumina and the glass. Sintering of the CASB glass powder alone at $900^{\circ}C$ resulted in full densification (99.5%). Sintering of alumina-filled composite at $900^{\circ}C$ also resulted in a substantial denslfication higher than 97% of theoretical density, In this case, the maximum volume percent of alumina should be less than 40%. XRD analysis revealed that there was a partial dissolution of alumina into the glass. This alumina dissolution, however, did not show the particle growth and shape accommodation. Therefore, the sintering of both the pure glans and the alumina-filled composite was mainly achieved by the viscous flow and the redistribution of the glass. Alumina dissolution accelerated the crystallization initiation time at $1000^{\circ}C$ and hindered the densification of the glass. Dielectric constants of both the alumina-filled glass and the glass-ceramic composites were increased with increasing alumina content and followed rule of mixture. In case of the glass-ceramic matrix composites showed relatively lower dielectric constant than the glass matrix composite. Furthermore, as alumina content increased, crystallization behavior of the glass was changed due to the reaction between the glass and the alumina. As alumina reacted with the glass matrix, the major crystallized phase was shifted from wollastonite to gehlenite. In this system, alumina dissolution strongly depended on the particle size: When the particle size of alumina was increased to 15 $\mu\textrm{m}$, no sign of dissolution was observed and the major crystallized phase was wollastonite.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.1 no.1
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• pp.59-70
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• 1991

ZnO fine powder was prepared by the batch precipitation process using $ZnCl_2$ and hexamethylenetetramine solution as a mother solution. When the concentrations of $ZnCl_2$solution were $0.1mol/\ell$ and 0.05mol/-, the particles of rod shape were obtained when the conentration of $ZnCl_2$solution was $0.01mol/\ell$, the particle of plate shape was obtained. When the hexamethylenetetramine as a precipitants was used, pH was raised slow during a few minute be-cause of slow hydrolysis rate of hexamethylenetetramine. For rapid raising of pH during initial reac-tion time, $NH_4$OH was added as nucleant. When $NH_4$OH as a nucleant was added, obtained particle was shape of granular and the mean particle size was $0.41\mu\textrm{m}$. After calcination at $500^{\circ}C$ during 1hour, all of remained organic phase was removed but the shape of particles was not changed. But pa-rticles were slightly shrunk in comparision with before calcined particles.

• Journal of environmental and Sanitary engineering
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• v.14 no.3
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• pp.123-129
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• 1999

The utilization methods of algae biomass have been studied constantly in whole world. These are $\circled1$the wastewater treatment if waste stabilization pond and oxidation ditch etc. and $\circled2$the biosorption of heavy metals and recovery of strategic' precious metals and $\circled3$the single-celled protein production and the production of chemicals like coloring agent and $\circled4$the production of electric energy through methane gasification. The culture system also has been developed constantly in relation with such utilization method developments. In the result of experimental operation under continuous and cyclic irradiation of light, using high rate algae biomass culture pond(HRABCP), which had been made so as to be an association system with the various items which had been managed to have high efficiency for algae culture, the algae production of the 12 hours-irradiance pond was 41.48 Chlorophyll-a ${\mu}g/L$ only in spite of having the more chance of $CO_2$ synthesis to algae cell than the 24 hours-irradiance pond. This means that the energy supply required for dark-reaction of photosynthesis is very important like this. The difference of algae production between continuous and cyclc irradiation explains that the dark-reaction of photosynthesis acts on algae production as the biggest primary factor. The continuous irradiance on HRABCP made the good algae-production($1403.97{\;}{\mu}g$ Chlorophyll-a/mg) and the good oxygen-production(5.8 mg $O_2/L$) and the good solid-liquid seperation. especially, DO concentration through the oxygen-production was enough to fishes' survival.

• Journal of Ocean Engineering and Technology
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• v.28 no.4
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• pp.314-323
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• 2014

In this study, a gearbox and blade were modeled in the MASTA program, and the housing and carrier components were modeled using a finite element method. Using substructure synthesis, all the components were combined and used to establish a vibration model of a 2.5-MW wind turbine gearbox. In addition, the safety displacement factor was evaluated using an AGMA data sheet about bearing's outer race for the input shaft and output shaft. As a result, the bearing's outer race for the input shaft, and the radial and axial responses were satisfied by the $1^{st}$ and $2^{nd}$ planetary gears and the $3^{nd}$ helical gear transmission error(TE), respectively. However, the output shaft support bearing's outer race responses were not satisfied with the radial response by the $2^{nd}$ TE and axial response by the $3^{rd}$ TE. To reduce the vibration, tooth modification was needed. After profile tooth modification, at the outer race of the output shaft support bearing, the radial response was reduced by approximately $20{\mu}m$, and the axial response was reduced by approximately $6{\mu}m$.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.139-143
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• 2005

Cytochrome P450 14${\alpha}$-sterol demethylase enzyme (CYP51) is the target a of azole type antifungals. The azole blocks the ergosterol synthesis and thereby inhibits fungal growth. A three-dimensional (3D) homology model of CYP51 from Candida albicans was constructed based on the X-ray crystal structure of CYP51 from Mycobacterium tuberculosis. Using this model, the binding modes for the substrate (24-methylene-24, 25-dihydrolanosterol) and the known inhibitors (fluconazole, voriconazole, oxiconazole, miconazole) were predicted from docking. Virtual screening was performed employing Structure Based Focusing (SBF). In this procedure, the pharmacophore models for database search were generated from the protein-ligands interactions each other. The initial structure-based virtual screening selected 15 compounds from a commercial available 3D database of approximately 50,000 molecule library, Being evaluated by a cell-based assay, 5 compounds were further identified as the potent inhibitors of Candida albicans CYP51 (CACYP51) with low minimal inhibitory concentration (MIC) range. BMD-09-01${\sim}$BMD-09-04 MIC range was 0.5 ${\mu}$g/ml and BMD-09-05 was 1 ${\mu}$g/ml. These new inhibitors provide a basis for some non-azole antifungal rational design of new, and more efficacious antifungal agents.

• Biomolecules & Therapeutics
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• v.5 no.1
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• pp.87-93
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• 1997

DA-5018, a new capsaicin derivative, showed potent analgesic effect comparable to that of morphine in various experimental acute pain models. in this study, whether the analgesic mechanism of DA-5018 is related to opiate receptors or prostanoids was investigated. The affinity of DA-5018 for opiate receptor was determined by receptor binding assay. The Ki values of DA-5018 for nonspecific and specific $\mu$, $textsc{k}$, $\delta$-opiate receptor was 299$\pm$8.88, 735$\pm$215, 2930$\pm$ 163, 1550$\pm$813 nM, respectively and DA-5018 exhibited lower affinity than morphine. DA-5018 (10-"~3$\times$10-′M) inhibited electrically-evoked contractions of the guinea ply ileum and rat vas deferens, and these inhibition was not antagonized by naloxone(10 nM), an opiate receptor antagonist. Antagonism of analgesic effect of 7A-5018 by naloxone was examined by tail pinch test. Analgesic action of DA-5018(0.1 ~2 mg/kg, 5.c.) was not antagonized by naloxone(1 mg/rg, i.p.). These results indicate that pharmacological action of DA-5018 is not related with opiate receptor. Cyclooxygenase and 5-lipoxygenase activities in rat peritoneal neutrophil treated with A23187 and arachidonic acid were measured by radioimmunoassay. DA-5018 stimulated the cyclooxygenase activity and the concentration show-ing the two fold increase of activity was 124$\mu$M. DA-5018 slightly inhibited 5-lipoxygenase activity and these results together indicate that analgesic action of 3A-5018 is not mediated through inhibition of cyclooxy genase or lipoxygenase. These results suggest that the analgesic effect of DA-5018 is not due to blocking opiate receptor or to inhibiting the synthesis of prostanoids in the arachidonic acid metabolism pathway.

• Biomolecules & Therapeutics
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• v.16 no.3
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• pp.277-285
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• 2008

Panax ginseng C.A. Mayer (Araliaceae, P. ginseng) has been used for the enhancement of vascular and immune functions in Korea and Japan for a long time. Ginsenoside $Rb_1$ and $Rg_3$ isolated from P. ginseng head-part butanolic extract (PGHB) were investigated for anti-inflammatory activity. Ginsenosides and PGHB did not affect the cell viability within $0\;-\;100\;{\mu}g/ml$ concentration to RAW 264.7 murine macrophage cells. Ginsenosides and PGHB inhibited partly lipopolysaccharide (LPS)-induced nitrite production in a dose-dependent manner. The ginsenosides and PGHB showed partially chemical nitric oxide (NO) quenching (maximum 40%) in the cell-free system. Also, ginsenoside $Rb_1$ and $Rg_3$ inhibited markedly approximately 74 and 54% of inducible nitric oxide synthase (iNOS) mRNA transcription from LPS-induced RAW 264.7 cells. Taken together, the inhibitory effect of ginsenosides and PGHB on NO production did not occur as a result of cell viability, but was caused by both the chemical NO quenching and the regulation of iNOS. Additionally, the ginsenoside $Rb_1$ and PGHB inhibited prostaglandin $E_2$ ($PGE_2$) synthesis in a concentration-dependent manner, showed approximately 70-98% inhibition at $100\;{\mu}g/ml$ concentration. And the treatment with ginsenosides and PGHB attenuated partially LPS-upregulated cyclooxygenase-2 (COX-2) gene transcription. Ginsenoside $Rg_3$ suppressed LPS-stimulated interleukin-6 (IL-6) level to the basal in RAW 264.7 cells. From these results, ginsenoside $Rb_1,\;Rg_3$, and PGHB may be useful for the relief and retardation of immunological inflammatory responses and its action may occur through the reduction of inflammatory mediators, including NO, $PGE_2$, and IL-6 production.

• Journal of Photoscience
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• v.10 no.2
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• pp.185-187
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• 2003

The preparation and the photophysics of organometallic Pt(II) and Ir(III) complexes with 6-ch1oro-3-phenylpyridazine (H6Clppdz) are reported. $K_2$PtCl$_4$ and IrCl$_3$ㆍn$H_{2}O$ cleanly cyclometalate with H6Clppdz, forming the corresponding chloro-bridged dimers, (6Clppdz)Pt($\mu$-Cl)$_2$Pt(6Clppdz) and (6Clppdz)$_2$Ir($\mu$-Cl)$_2$Ir(6Clppdz)$_2$ in good yield. These chloro-bridged dimers are cleaved with acetylacetone (Hacac) to give the corresponding monomer, (6Clppdz)Pt(acac) and (6Clppdz)$_2$ Ir(acac), respectively. Both complexes show bright orange luminescence at room temperature and the emission wavelengths are different depending on the metal and the structure of complexes. (6Clppdz)Pt(acac) shows two sharp emission bands in shorter wavelength ($\lambda$$_{em}$=541 and 580 nm), while (6Clppdz)$_2$ Ir(acac) shows a broad emission band in longer wavelength ($\lambda$$_{em}$=615 nm). Strong spinorbit coupling due to the heavy metal atom allows for the formally forbidden mixing of the $^1$MLCT with the $^3$MLCT and $^3$$\pi$-$\pi$$^{*}$ states.

• Korean Journal of Microbiology
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• v.47 no.1
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• pp.30-37
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• 2011

This ultra real-time PCR (UPCR) based diagnosis system for avian influenza A virus (AIV) subtype was designed. The target primer in this study was derived from H5N1 subtype-specific 133 bp partial gene of hemagglutinin (HA), and was synthesized by using PCR-based gene synthesis on the ground of safety. UPCR was operated by Mini-Opticon Q-PCR Quantitative Thermal Cycler using aptamer-based molecular beacon, total 10 ${\mu}l$ of reaction mixture with extraordinarily short time in each steps in PCR. The detection including UPCR and analysis of melting temperature was totally operated within 15 min. The AIV-specific 133 bp PCR product was correctly amplified until 5 molecules of HA gene as minimum of templates. This kind of PCR was drafted as UPCR in this study and it could be used to detect not only AIV subtype, but also other pathogens using UPCR-based diagnosis.