• Journal of Life Science
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• v.15 no.5 s.72
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• pp.749-754
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• 2005

An antioxidant- producing bacterium was isolated from sea water in Jeju island. The isolated strain, SC2-1 was gram-positive, catalase positive, facultatively anaerobic, oxidase negative, motile and small rods. The strain utilized sucrose, dextrose, fructose, mannitol and maltose as a sole carbon and energy source and sodium chloride was required for the bacteria growth. The radical scavenging activity of the culture supernatants was determined by DPPH (1,1-diphenyl-2-picrylhydrazyl) method. This bacterium was identified based on cellular fatty acids analysis and 16S rDNA sequencing, and then named Exiguobacterium sp. SC2-1. The modified optimal medium compositions required the addition of maltose $2.5\%(w/v)$, yeast extract $1.5\%(w/v)$ and $KH_{2} PO_{4} 0.05\%(w/v)$ in marine broth (Difco. Co. USA). Antioxidant activity of under optimal culture conditions were $93\%$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.4
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• pp.307-313
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• 1992

To study the seasonal variation of heterotrophic bacteria near the surrounding seawater of Porphyra forming area, samples were collected in the intertidal waters of Mokp'o of the Yellow Sea from February to December, 1990. Annual distribution of heterotrophic bacteria ranged from $7.5\times10^2\;to\;1.1\times10^5\;cfu/ml,$ annual distribution of physiological characteristic bacteria ranged from $5.0\times10\;to\;4.34\times10^4\;cfu/ml$ for proteolytic bacteria, from 0 to $1.35\times10^4\;cfu/ml$ for lipolytic bacteria and from 0 to $1.2\times10^4\;cfu/ml$ for amylolytic bacteria. Sixty-five percent of isolates from seawater were rods, and $76.7\%$ of isolates were Gram-negative. Most isolates were mesophiles and showed utilization of various carbon sources such as glucose, maltose, lactose, sucrose and arabinose. Most isolates also showed tolerance to a broad range of salt concentration. Dominant genus in seawater were Flavobacterium spp., in February, Moraxella spp., Acinetobacter spp. in March, Bacillus spp., Chromobacterium spp., Micrococcus spp., Vibrio spp. in July and Chromobacterium spp., Micrococcus spp., Bacillus spp. in November.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.4
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• pp.314-321
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• 1992

To study the seasonal variation of heterotrophic bacteria on the blades of Porphyra species, samples were collected In the intertidal zone near Mokp'o of the Yellow Sea from February to December, 1990 Annual distribution of heterotrophic bacteria on the blades of Porphyra species ranged from $6.9\times10^2\;to\;1.04\times10^5\;cfu/cm^2$ at site 1, and from $9.4\times10^3\;to\;2.93\times10^5\;cfu/cm^2$ at site 2. Average sixty-five percent of isolates from the blades of Porphyra species were rods and $52.1-82.7\%$ of isolates were Gram-negative. Most isolates showed starch hydrolysis$(68\%)$ on March, but showed Poor utilization of carbon sources and no $H_2S$ production. Dominant genus isolated from the baldes of Porphyra species were Alcaligenes spp., Moraxella spp., on March and Micrococcus spp., Moraxella spp., Corynebacterium spp., on November.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.6
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• pp.871-885
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• 2017

Nowadays, the construction of tunnels with a shallow depth drastically in urban areas increases. But the effect of sidewall displacement in shallow tunnel on its behavior is not well known yet. Most studies on the shallow tunnel have been limited to the stability and the failure of the tunnel and the adjacent ground in plane strain state. Therefore, the model tests were conducted in a model ground which was built with carbon rods, in order to investigate the impact of the tunnel sidewall displacement on the lateral load transfer to the adjacent ground. The lateral displacement of the tunnel sidewall and the load transfered to the adjacent ground were measured in model tests for various overburdens (0.50D, 0.75D, 1.00D, 1.25D). As results, if the cover depth of tunnel was over a constant depth (0.75D) in a shallow tunnel, the tunnel sidewall was failed with a constant shape not depending on the tunnel cover depth and also not affected by the opposite side of the wall. But, if the cover depth of tunnel was under a constant depth (0.75D), the failure of the tunnel sidewall could affect the opposite sidewall. In addition, if the displacement of tunnel sidewall with 50% of the critical displacement occurred, the tunnel failure was found to be at least 75%. However, additional studies are deemed necessary, since they may differ depending on the ground conditions.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.3
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• pp.247-255
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• 2016

In order to select a strain that forms a Biocellulose (BC), strain producing acetic acid was selected from commercially available kombucha. Through SM broth it was confirmed that the strain is a gram negative bacteria in the form of rods having no motility through a phase contrast microscope. The result of phylogenetic inference analysis based on 16S rDNA sequence analysis for the identification of strains was most closely related to Gluconobacter uchimurae (G. uchimurae) and was named G. uchimurae GYS15 strain. The strain showed the highest degree of growth when cultured for 14 days under the conditions of pH 5 and $25^{\circ}C$. Moreover, it showed the highest degree of growth in a Glucose addition disaccharide as the optimum carbon source sucrose and fructose. Also, 0.5% NaCl, upon the addition of Malto extract, showed the highest degree of growth. Based on investigation by the optimum growth conditions to confirm the physical properties of BC obtained by culturing G. uchimurae GYS15 strains. The surface structure was observed through an scanning electron microscope (SEM) showed a high networks structure. It until $8.6{\pm}0.38$ times when the water holding capacity is re-absorbed and re-absorbed holding oil up to $6.6{\pm}0.51$ times confirmed. In conclusion, using these material properties, it was possible to confirm the possibility of a variety of cosmetic materials and mask pack materials.

• Journal of the Korean Geotechnical Society
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• v.35 no.5
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• pp.21-30
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• 2019

While the study of the shallow tunnel has been mainly on the longitudinal load transfer and horizontal surface conditions, the study of the ground behavior of shallow tunnel under the slope is not sufficient. Therefore, in this study on the ground behavior around a tunnel due to the sidewall deformation of shallow tunnel under the slope that is excavated in longitudinal direction, a scale-down model test has been performed. The model tunnel has the dimension of 320 mm wide, 210 mm high and 55 mm long with enough material strength in aluminum and the model ground has the uniform ground conditions by 3 types of carbon rods. The model test has been performed with the variables of slopes and the cover depths by controlling the tunnel sidewall deformation, and the change of sidewall-load, load transfer, ground subsidence was monitored and analyzed. According to the increase of the slope, the maximum ground subsidence increased by 20~39% compared to the horizontal surface. The load ratio increased by maximum 20% in the tunnel crown and decreased in sidewall according to the surface slope. The load transfer shows maximum 128% of increase at the cover depth of 1.0D, while at the 1.5D cover depth it shows non-critical difference from horizontal surface. The slope has major effects on load transfer at the cover depth of 1.0D.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.5
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• pp.761-778
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• 2017

The need of the underground space for the infrastructures in urban area is increasing, and especially the demand for shallow tunnels increased drastically. It is very important that the shallow tunnel in the urban area should fulfill not only its own safety conditions but also the safety condition for the adjacent structures and the surrounding sub-structure. Most of the studies on the behavior of shallow tunnels concentrated only on their behaviors due to the local deformation of the tunnel, such as tunnel crown or tunnel sidewall. However, few studies have been performed for the behavior of the shallow tunnel due to the deformation of the entire tunnel. Therefore, in this study the behavior of the surrounding ground and the stability caused by deformation of the whole tunnel were studied. For that purpose, model tests were performed for the various ground surface slopes and the cover depth of the tunnel. The model tunnel (width 300 mm, height 200 mm) could be simulationally deformed in the vertical and horizontal direction. The model ground was built by using carbon rods of three types (4 mm, 6 mm, 8 mm), in various surface slopes and cover depth of the tunnel. The subsidence of ground surface, the load on the tunnel crown and the sidewall, and the transferred load near tunnel were measured. As results, the ground surface subsided above the tunnel, and its amount decreased as the distance from the tunnel increased. The influence of a tunnel ceased in a certain distance from the tunnel. At the inclined ground surface, the wider subsidence has been occurred. The loads on the crown and the sidewall were clearly visible, but there was no effect of the surface slope at a certain depth. The load transfer on the adjacent ground was larger when the cover depth (on the horizontal surface) was lager. The higher the level (on the inclined surface), the wider and smaller it appeared. On the shallow tunnel under inclined surface, the transfer of the ambient load on the tunnel sidewall (low side) was clearly visible.