• Microbiology and Biotechnology Letters
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• v.19 no.1
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• pp.82-87
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• 1991

Xanthomonns curnpestris M12, Xunthornonas sp. M28, Acinetuhucter Iwofz GI, and Klebsiella pneumoniae L25, Pseudomonas rnaltophiliu N246 were screened to increase the ability for crude oil utilization. All of these could utilize hexadecane and octane with the exception of N246 strain for only octane biodegradation. Thus N246, M12, and M28, strains were specially examined for octane oxidation. Octane biodegradation by three strains showed the optimal conditions at $30^{\circ}C$, pH 7.0~9.0, and 0.2~0.3% octane concentration as a substrate. It was found that P. multofihila N246 and X. curnpestns M12 had plasmid and the cured plasmid from N246 strain lost octane uitilization. Therefore, it was confirmed that certain genes for octane utilization were Iocated on OCT plasmid in N246 strain. The size of OCT plasmid in N246 strain was 118 kb. The N246 strain was resistant to ampicillin.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.271-271
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• 2010

Using ab initio density functional theory, we investigate the dimerization and one-dimensional (1-D) polymerization of metal-encapsulated gold nanoclusters, M@$Au_{12}$ (M=W, Mo) and their structural and electronic properties. M@$Au_{12}$ clusters with a magic number 13 can form icosahedral and cuboctahedral structures. We consider various dimer configurations with different compounds and symmetries to find the most stable dimer structure in each case. Au atoms in the one cluster, which participate directly in dimerization, tend to form triangular bonds together with counterpart Au atoms in the other. It is found that both M@$Au_{12}$ and M@$Au_{12}$ clusters are stabilized by about 3 eV due to dimerization. We also calculate and compare the electronic and magnetic properties of different dimerized clusters. Based on our investigation on dimerization, we further study on 1-D polymerization of M@$Au_{12}$ with different compounds and symmetries. We will also discuss their formation energies as well as their electronic and magnetic properties.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.445-445
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• 2022

최근 새만금 방조제 건설이 완료됨에 따라 주변 연안지역의 지형에 많은 변화가 감지되었다. 본 연구대상지는 격포해수욕장으로서 새만금 사업 준공 후 연안침식에 따른 모래 유실 등으로 인해 양빈사업 등이 검토되고 있는 상황이다. 본 연구에서는 연안지형 변화 탐지를 위한 UAV (Unmanned Aerial Vehicle) 활용기술을 제시하는 것으로서 총 3회에 걸쳐 UAV 영상을 촬영하였다. 영상촬영은 DJI Inspire 2 UAV를 활용하였으며 VRS(Virtual Reference Service) 측량성과와 연계하여 Pix4D Mapper SW를 통해 정사영상과 수치표면모델(DSM; Digital Surface Model)을 제작하였다. 먼저 2018. 6. 29 ~ 2018. 12. 10 사이의 지형변화 탐지를 수행한 결과 침식과 퇴적의 최대값은 각각 2.56m와 2.24m로 나타났으며 평균적으로는 0.01m의 퇴적이 발생하였다. 그리고 2018. 6. 29 ~ 2019. 6. 14 동안의 침식과 퇴적의 최대값은 각각 2.31m와 2.28m로 나타났으며 평균값은 0.02m의 침식이 발생하였다. 또한 2018. 12. 10 ~ 2019. 6. 14 사이에는 침식과 퇴적의 최대값이 각각 2.28m와 2.55m로 나타났으며 평균값은 0.03m의 침식이 발생하였다. 지형변화를 보다 상세히 모니터링하고자 퇴적과 침식구간을 나누어 분석을 수행한 결과, 2018. 6. 29 ~ 2018. 12. 10 사이에는 0.5m 이내의 침식과 퇴적구간 면적이 각각 13,324.4m²와 14,667.3m²로 퇴적구간의 면적이 1,342.9m² 만큼 높게 나타났으며, 2018. 12. 10 ~ 2019. 6. 14 사이에는 0.5m 이내의 침식과 퇴적구간 면적이 각각 16,176.6m²와 11,723.0m²로 침식구간의 면적이 4,453m² 만큼 높게 나타났다. 또한 2018. 12. 10 ~ 2019. 6. 14 사이에는 0.5m 이내의 침식과 퇴적구간 면적이 각각 16,821.6m²와 11,126.4m²로 침식구간의 면적이 5,695.2m² 만큼 크게 분석되었다. 이와 같이 UAV 영상 기반의 연안지형 모니터링을 수행할 경우 시계열 지형변화를 효과적으로 모니터링할 수 있으며, 이러한 업무는 새만금 방조제 건설에 따른 지형변화의 영향평가 등 다양한 연안업무에 활용될 수 있을 것이다.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.3
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• pp.164-168
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• 2017

This study experimentally determined the effect of calcium ion ($Ca^{2+}$) (0-0.55 mM) and intial pH (4.0-10.0) on phosphorus (P) removal in synthetic wastewater (2 mg P/L) using titanium tetrachloride ($TiCl_4$) (0.12-0.18 mM). At TiCl4 concentration ([$TiCl_4$]) = 0.12 mM, the P removal efficiency was the highest (95.1%) at pH 7 but the efficiency decreased to 51.4% at pH 8. The P removal efficiency was 55.6% at $Ca^{2+}$ concentration ([$Ca^{2+}$]) = 0 mM but the efficiency increased to 90.5% at [$Ca^{2+}$] = 0.045 mM at [$TiCl_4$] = 0.12 mM. On the other hand, the P removal efficiency difference was not large (96.5-99.5%) with [$Ca^{2+}$] at [$TiCl_4$] = 0.15-0.18 mM. Within the design boundaries of $0.00{\leq}[Ca^{2+}]{\leq}0.18mM$ and $7.0{\leq}initial$ $pH{\leq}9.0$ at [$TiCl_4$] = 0.12 mM, the 90% P removal efficiency could be achieved at $[Ca2+]{\geq}0.10mM$ with pH 8.0 and $[Ca2+]{\geq}0.12mM$ with pH 9.0.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.2
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• pp.196-200
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• 1993

A full understanding of the interdependence of leaf nitrate (($No_3$￣) metabolism and symbiotic nitrogen($N_2$) fixation in legume crops is needed to help maximize the use of both N sources as well as to improve forage quality through the inhibition of leaf nitrate accumulation. The present work examines the effects of added nitrate, the level of which are 0,2,4,8 and 12mM, on the nodule formation and leaf nitrate utilization and on the possibility of inducing nitrate-toxicity to livestocks in two alfalfa varieties, ' Vernal ' of grazing type and ' Victoria ' of hay type. Higher level of exogeneous nitrate resulted in the increased above-ground dry weight. Nodulation was inhibited severely when more than 8mM NO$_3$￣ was supplied to alfalfa plants, and leaf nitrate reductase reached a maximunm at 4mM nitrate supply. The $V_{max}$of nitrate reductase in leaves of Vernal was similar to that of Victoria, whereas the $K_m$ of Vernal was higher than that of Victoria. High accumulation of leaf nitrate, $4{\times}10^{-5}$ g/g leaf fresh weight, was shown at 12mM nitrate supply, which was thought to be not enough to induce nitrate-toxicity to livestocks.icity to livestocks.

• Korean Journal of Plant Taxonomy
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• v.42 no.4
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• pp.307-315
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• 2012

Somatic chromosome numbers for 10 taxa and karyotypes analysis for 6 taxa of Korean Vicia were investigated. Somatic chromosome numbers of treated taxa were 2n = 12, 14 or 24 and therefore they proved to be diploid or tetraploid with basic chromosome numbers of x = 6 or 7. The chromosome number of V. hirticalycina (2n = 2x = 12) was reported for the first time in this study. The chromosome numbers of nine taxa were the same as in previous studies; V. angustifolia (2n = 2x = 12), V. cracca (2n = 4x = 24), V. hirsuta (2n = 2x = 14), V. tetrasperma (2n = 2x = 14 + 2B), V. amurensis (2n = 2x = 12), V. chosenensis (2n = 2x = 12, 12 + 2B), V. unijuga (2n = 4x = 24), V. unijuga f. minor (2n = 4x = 24), V. venosa var. cuspidata (2n = 4x = 24). The karyotypes of V. cracca, V. amurensis, V. hirticalycina, V. unijuga, V. unijuga f. minor, V. venosa var. cuspidata were observed as 2 m + 8 sm + 2 st, 2 m + 2 sm + 2 st, 3 m + 1 sm + 2 st, 4 m + 6 sm + 2 st, 4 m + 6 sm + 2 st, 4 m + 8 sm, respectively.

• Applied Chemistry for Engineering
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• v.3 no.1
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• pp.53-63
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• 1992

M/BM -series catalysts, $MoO_3$ supported on ${\alpha}-Bi_2Mo_3O_{12}$ were also prepared by impregnation method. BM/M-series catalysts, ${\alpha}-Bi_2Mo_3O_{12}$ supported on $MoO_3$ were also prepared by coprecipitation. Structure and catalytic properties of the two phase catalysts were studied by means of using nitrogen adsorption, X-ray diffraction, and scanning electron microscopy. The reaction test for the selective oxidation of propylene to acrolein over Bi-molybdate catalysts was studied using a fixed-bed reactor system. In M/BM-series catalysts, $MoO_3$ was dispersed on ${\alpha}-Bi_2Mo_3O_{12}$, and the crystal structure of ${\alpha}-Bi_2Mo_3O_{12}$ remains unchanged by the presence of excess $MoO_3$. However the surface morphology and bulk structure of BM/M-series catalysts were altered probably because the precipitated $Bi(OH)_3$ reacted with $MoO_3$ during the calcination to form ${\alpha}-Bi_2Mo_3O_{12}$ phase. The results of propylene oxidation on both series catalysts showed that the reaction took place over the surface of ${\alpha}-Bi_2Mo_3O_{12}$ particle and the role of excess $MoO_3$ was to supply oxygen to ${\alpha}-Bi_2Mo_3O_{12}$. These increasing effects on activity were also observed in the mechanical mixtures of ${\alpha}-Bi_2Mo_3O_{12}$ and $MoO_3$.

• Archives of Pharmacal Research
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• v.29 no.8
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• pp.645-650
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• 2006

Tributyltin chloride (TBTC) at concentrations of $0.5-1.0\;{\mu}M$ inhibits dopamine biosynthesis in PC12 cells. In this study, the effects of TBTC on L-3,4-dihydroxyphenylalanine (L-DOPA)-induced cytotoxicity in PC12 cells were investigated. TBTC at concentrations up to $1.0\;{\mu}M$ neither affected cell viability, nor induced apoptosis after 24 or 48 h in PC12 cells. However, TBTC at concentrations higher than $2.0\;{\mu}M$ caused cytotoxicity through an apoptotic process. In addition, exposure of PC12 cells to non-cytotoxic (0.5 and $1.0\;{\mu}M$) or cytotoxic $(2.0\;{\mu}M)$ concentrations of TBTC in combination with L-DOPA (20, 50 and $100\;{\mu}M$) resulted in a significant increase in cell loss and the percentage of apoptotic cells after 24 or 48 h compared with TBTC or L-DOPA alone. The enhancing effects of TBTC on L-DOPA-induced cytotoxicity were concentration- and treatment time-dependent. These data demonstrate that TBTC enhances L-DOPA-induced cytotoxicity in PC 12 cells.

• YAKHAK HOEJI
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• v.50 no.2
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• pp.105-110
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• 2006

The effects of tributyltin acetate (TBTA), one of the endocrine-disrupting organotin compounds, on dopamine biosynthesis in PC12 cells were investigated. Treatment of PC12 cells with TBTA at $0.05\sim0.25{\mu}M$ significantly decreased the intracellular dopamine content in a concentration-dependent manner ($IC_{50}$ value, $0.17{\mu}M$). Under these conditions, tyrosine hydroxylase (TH) activity and TH mRNA level were also decreased by $0.1{\mu}M$ TBTA at 24 h, and recovered there-after. In addition, treatment with L-DOPA at 20 and $50 {\mu}M$ increased the intracellular dopamine content in PC12 cells and the increase in dopamine content by L-DOPA was significantly abolished by TBTA at $0.1\sim0.2{\mu}M$. These results indicate that TBTA at $0.1\sim0.2{\mu}M$ causes the decrease in the basal dopamine content and abolishes the increase in dopamine content in L-DOPA-treated cells in part by the inhibition of TH gene expression and activity.

• Polymer(Korea)
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• v.37 no.5
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• pp.571-578
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• 2013

Polyamide12 (PA12) is blended with ethylene propylene diene rubber (EPDM) at various compositions in the presence of maleated EPDM (mEPDM) to afford blend materials having the characteristics of thermoplastic elastomer (TPE). The EPDM/PA12 melt-blends are further irradiated with electron-beam (e-beam) at 0~100 kGy dosage, yielding selective crosslinking between EPDM chains while retaining melt-processibility originated from PA12 phase. mEPDM acts as a compatibilizer and affords additional improvements in mechanical properties of the EPDM/PA12 blend. With 25 kGy of e-beam irradiation and mEPDM, the EPDM/PA12 blends successfully exhibit TPE behaviors with reasonable elastomeric and mechanical properties.