• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.2
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• pp.119-125
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• 2008

The aim of this study was to determine the characteristics of wave transformation in the shallow water of the Nakdong River estuary due to variations in air pressure, air temperature, wind speed, and wind direction. We analyzed the correlation between weather factors and wind waves in offshore regions near Geoje Island and the Nakdong River estuary in April and May 2007. The weather and wind wave data were obtained from the automatic ocean observation buoy near Geoje Island operated by the Korean Meteorological Administration (KMA). For the estuary region, the wind wave information was the result of field observations, and weather data were obtained from the Busan Meteorological Station. Field observations of water waves in April and May showed that the maximum wave height decreased by about 2.2 m. M oreover, wave height decreased significantly by about 1.3 m due to the reduction in wave energy caused by the water waves propagating from Geoje buoy to the Nakdong River estuary. We conclude that offshore or wind waves coming into the Nakdong River estuary showed considerable height variation due to the prevailing weather conditions, especially wind speed and direction. In particular, headwinds tended to decrease the wave size in inverse proportion to the wind speed.

• Applied Biological Chemistry
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• v.41 no.5
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• pp.399-404
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• 1998

Genipin was obtained from hydrolysis of geniposide isolated from gardenia fruits with ${\beta}-glucosidase$. Reaction of genipin with glycine, alanine, histidine, lysine, phenylalanine and glutamate in aqueous buffer solution converted colorless starting materials to blue pigments. Effect of pH for the formation of blue pigments was tested using UV/Vis spectrophotometer. The optimum pH for the formation of blue pigments was 7.0. No pigment and trace amounts were formed at acidic (pH 3.0) and alkaline (pH 12.0) conditions, respectively. The amount and tincture of blue color were distinct with different amino acids. In contrast with lysine $({\lambda}_{max}=573\;nm)$, glycine $({\lambda}_{max}=595\;nm)$, phenylalanine $({\lambda}_{max}=602\;nm)$ and alanine $({\lambda}_{max}=595\;nm)$, the reaction of genipin with histidine $({\lambda}_{max}=601\;nm)$ and glutamate $({\lambda}_{max}=601\;nm)$ produced relatively small amounts of blue pigments. Rate constants for the formation of blue pigments from genipin with amino acids at various temperatures $(60,\;70,\;80,\;90^{\circ}C,\;pH\;7.0\;phosphate\;buffer)$ were obtained. Rate constants of genipin with basic amino acids were larger than neutral or acidic amino acids. Arrhenius activation energies of the formation of blue pigments indicated that activation energy of glycine $(E_A=9.8\;kcal/mol)$ was especially lower than those of other amino acids $(E_A=13.3{\sim}15.4\;kcal/mol)$.

• Journal of The Korean Association For Science Education
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• v.33 no.2
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• pp.284-309
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• 2013

This study aims to explore how to characterize high school science inquiry. For this research, data were collected from fifteen science classes (18 hours), through observation and videotaping, interviews with a few students and their teacher, and documents such as lesson plan or activity sheet in 13 Science Core High Schools. All the data were transcribed and analyzed. Analyses of these transcripts were proceeded in three steps: first, classroom cases showing active interactions between teacher-students and among students were selected; second, according to cognitive process of inquiry (Chinn & Malhotra, 2002), each segment was analyzed and interpreted; lastly, distinctive cases were determined to show essential features of school science inquiry. Based on the analyses, we characterize high school science inquiry in terms of features of variables controlling-device improvement, design studies, evidence-explanation transformation, and reasoning to formulate explanations from evidence. Teachers' role and educational support were discussed as well as the practical characters or features of school science inquiry.

• Korean Chemical Engineering Research
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• v.45 no.4
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• pp.378-383
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• 2007

A novel fabrication method for the multi-component metal oxides such as zirconium titanate($Zr_xTi_{1-x}O_2$) has been suggested, which would yield the uniform film characteristics and control the film composition at relatively low process temperature. The method has the basic concept that firstly layer-by-layer structure is constructed with the primitive oxide layers, which are components of the desired multi-component oxides, and secondly the film is annealed at appropriate thermal conditions for the transformation to a single-phase multi-component oxides. In this study, PRTMOCVD(pulsed rapid thermal metalorganic chemical vapor deposition) possessing the superior thickness controllability was introduced to prepare $ZrO_2$ and $TiO_2$ thin film for zirconium titanate. Single-phase zirconium titanate thin films have been prepared successfully by the interdiffusion of oxide multilayers having several alternating layers of $ZrO_2$ and $TiO_2$. The Zr/Ti ratio of zirconium titanate could be controlled easily by altering the thickness of $ZrO_2$ and $TiO_2$ thin film.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.680-684
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• 2004

The hemangioma, a benign proliferation of blood vessel, is the most common tumor of infancy and childhood. In many instances, the lesion probably represents a hamartoma or malformation rather than a true neoplasm. In the oral cavity, common sites are lips, followed by tongue, buccal mucosa and palate. Clinical characteristics appear as a flat or raised reddish-blue lesion and are generally solitary. They are classified on the basis of their histological appearance into capillary, mixed, cavernous or a sclerosing variety. A 6-year-old male of this case was referred to the Department of Pediatric Dentistry, Chonnam National University with a chief complaint of swelling lesion on gingiva. The strawberry appearance mass was detected by clinical examination on attached gingiva at the upper left primary lateral incisor and canine. Surgical excision and biopsy were carried out for histological examination and the lesion was diagnosed with a capillary hemangioma. The risk of recurrence after this therapy is rare, and there is no malignant transformation. Despite their benign origins and behaviour, hemangiomas in the region of oral cavity are always clinically important to the dental profession because of bleeding tendency.

• Korean Journal of Optics and Photonics
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• v.16 no.2
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• pp.168-173
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• 2005

Ag-doped $TiO_2$ thin films were prepared by RF magnetron co-sputtering method, and their physical and chemical properties were examined as a function of calcination temperature. XRD results showed that the crystallite size of Ag-doped films was smaller than that of the $TiO_2$ thin films. SEM results showed that the particle size of $Ag/TiO_2$ film was smaller and more uniform than pure $TiO_2$ film. The films had high transparency in the visible range. The films calcined at $600^{\circ}C$ were the anatase phase, and the films calcined at $900^{\circ}C$ were a mixture of anatase and rutile phases. The absorption edge of films calcined at $900^{\circ}C$ was red-shifted. This is due to the augmented absorption resulting from the phase transformation from anatase to rutile phase. And the transmittance of films decreased by the light scattering and absorption in the films. Photocatalytic activity of $Ag/TiO_2$ thin films was higher than that of the pure $TiO_2$ thin films.

• Journal of Life Science
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• v.17 no.10
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• pp.1426-1433
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• 2007

To investigate the antibiotic resistant patterns of the bacteria producing ESBL, we isolated one organism of Klebsiella pneumoniae from a clinical laboratory in Busan. The organism that produces ESBL gene was detected by double disk synergy test and the presence of three ESBL genes (TEM-1, SHV-12, CTX-M-15) was confirmed by polymerase chain reaction and DNA sequencing analysis. To analyse the characteristics of three ESBL genes, we performed transconjugation, transformation and cloning experiment with the organism. The MIC of Klebsiella pneumoniae was revealed that ceftazidime, cefotaxime and ceftriaxone were $256\;{\mu}g/ml,\;128\;{\mu}g/ml\;and\;128\;{\mu}g/ml$ respectively. The MIC of conjugant (E. coli $RG176^{Na(r)}$) af was revealed that ceftazidime, cefotaxime and ceftriaxone were $256\;{\mu}g/ml,\;64\;{\mu}g/ml\;and\;128\;{\mu}g/ml$ respectively. The MIC of transformant (E. cofi $DH5{\alpha}$) was revealed that ceftazidime, cefotaxime and ceftriaxone were $128\;{\mu}g/ml,\;32\;{\mu}g/ml,\;and\;32\;{\mu}g/ml$ respectively, The MIC of cloned organism of SHV-12 gene (E. coli $DH5{\alpha}$) was revealed that ceftazidime, cefotaxime and ceftriaxone were $128\;{\mu}g/ml,\;8\;{\mu}g/ml,\;and\;32\;{\mu}g/ml$ respectively. The results indicated that MIC of conjugant was higher than MIC of transformant and also SHV-12 gene were not resistant against cefotaxime antibiotic.

• The Korean Journal of Ecology
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• v.28 no.2
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• pp.93-98
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• 2005

The effects of the presence of a submerged plant, Zizania latifolia, on physico-chemical characteristics, including Eh, pH, and concentrations of nitrogen and phosphorus in the sediments were studied under pot culture condition. It was shown that Eh value at reduced layer of the sediments was higher in the planted pots than in the non-planted. It was also revealed that $NH_4^+-N$ concentration of the sediments in the planted pots was lower than that of the non-planted, which might be due to the uptake by the plants. In contrast, $NO_3^--N$ concentration in the sediment increased in the presence of the plants compared to the non-planted, which might be attributed to oxygen released from the roots to the reduced layer. The concentration of organic phosphorus in the sediments was much higher than that of NAIP at the beginning of the planting experiment. However, at the end of the experiment, it was reversed; NAIP concentration was much higher than that of organic phosphorus, possibly indicating the transformation of organic phosphorus to NAIP during the experimental period. Both concentrations of $NH_4^+-N$ and $PO_4^{3-}-P$ in the overlying and percolated water were lower in the planted pots than in the non-planted. The concentration of $NO_3^--N$ in the percolated water, however, was higher in the planted pots than in the non-planted. The data was discussed with regard to the potential effects of a submerged plant on dynamics of phosphorus and nitrogen in the rhizosphere of the sediment.

• Proceedings of the Korean Fiber Society Conference
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• 1990.06b
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• pp.36-37
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• 1990

In the past, facile dissolution of cellulose has been hampered by the lack of suitable nondegrading solvents. Recently, this problem has been solved in our laboratory by the discovery of an inexpensive, convenient solvent system, that is the mixture of $NH_3\;and\;NH_4SCN$, for cellulose. Also, the $cellulose/NH_3/NH_4SCN$ solution system has been found to form the anisotropic, i.e., liquid crystalline phase. It is believed that both the cholesterio and the nematic phase occur. This finding has prompted extensive on-going researoh on the formation of the liquid crystalline phase from an inexpensive natural source such as cellulose since the nematic phase is envisioned as an excellent precursor sources for products with desirable properties, for example, high modulus and high strength. This interest naturally leads to a desire to understand the theological properties of the nematic phase so that the transformation of the nematic phase to the solid state with desirable properties can be efficiently accomplished, ;From this point of view, the theological behavior of the $cellulose/NH3_/NH_4SCN$ system has been studied as a function of shear rate and shear stress over a wide range of solvent compositions, cellulose concentration, centrifugation and urea contents, Results indicate that the viscosity decreases with increasing shear rate. A marked shear thinning behavior and a quasi-Newtonian behavior were observed in the low shear rate region and in the high shear rate region, respectively for all solvent compositions. The $cellulose/NH_3/NH_4SCN$ solution system only exhibited the viscosity increase with increasing cellulose concentration and failed to show the viscosity drop generally observed at the point of incipience of liquid crystal formation, This may be due to the gel-like nature of the solution by the association of the rodlike molecules into bundles which may serve as crosslinking points giving the cellulose solution a network structure. Also, simply hydrogen bonding may be so restrictive of molecular mobility that a viscosity drop is blocked. In addition to the above results, yield stress and thixotropy were also observed in the $cellulose/NH_3/NB_4SCN$ solution system which are characteristics of liquid crystal and gel, The results of the effect of centrifugation on viscosity show that viscosity decreases by the application of centrifugation. This may be explained by the change of the piled polydomain structure to the dispersed polydomain structure due to the pressure gradient generated during centrifugation.ation.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.243-250
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• 2004

In an effort to optimize tissue culture responses of Italian ryegrass(Lolium multiflorum Lam.) for future genetic manipulations to improve forage characteristics, the effects of culture medium supplements on tissue culture responses were investigated with mature seeds of three cultivars, 'Jeanne', 'Florida-80' and 'Metro', as explant tissues. For all explants, MS medium containing 5mg/L 2,4-D was optimal for embryogenic callus induction from mature seed and had a strong effect on successive plant regeneration. The optimal concentration of dicamba for the induction of embryogenic callus from mature seeds was 7mg/L. The highest plant regeneration frequency was observed when embryogenic callus was transferred to N6 medium supplemented with 1mg/L 2,4-D and 5mg/L BA. Plant regeneration frequency of callus cultured in the dark was higher than that of cultured in the light. Casein hydrolysate and L-proline improved both in embryogenic callus induction from mature seeds and plant regeneration. High-frequency regeneration system established in this study will be useful for molecular breeding of Italian ryegrass through genetic transformation.