• Journal of Life Science
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• v.11 no.6
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• pp.530-536
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• 2001

Several bacterial strains utilizing crude oil as their sole carbon and energy source were isolated from marine environment polluted by crude oil. Among them, the selected strain 4A3 showed strong degradation activity for crude oil. This strain was identified as a Provindencia rettgeri 4A3 based on the morphological, biochemical, and physiological characteristics. The optimum cultural conditions was as follows; 26$^{\circ}C$ for temperature and 7.0 for initial pH. Additionally, the optimal concentration of sodium chloride was 2.0%, indicating that this strain was derived from sea water. The emulsifying activity of 4A3 was the highest after 3 days of cultivation under the condition of 2.0% sodium chloride, pH 7.0 and 26$^{\circ}C$. This strain had one cryptic plasmid in 7.0kb size.

• 한국해양학회지
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• v.24 no.3
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• pp.121-131
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• 1989

Cold water observed at sea surface near the southeastern coast of Korea in summers 1982 and 1983 was studied by using data of hydrography, sea level, wind and satellite image. In summer season when water column shows 3-layered structure a "full" upwelling occurs by southwesterly transient wind continuing for several days. During upwelling event, surface water of high temperature moved offshore, middle water of low temperature outcropped to the sea surface, and sea level was lowered, however, equilibrium depth of surface layer was not changed. It may be concluded that cold water at the surface originates from middle layer and strong surface front is a result of surfacing of seasonal thermocline. In order to see the relationship between position of surface front and wind input, a model of Csanady (1982) was applied in a rigid lid approximation. The results show that frontal position can be determined by wind input and water structure near the southeastern coast of Korea. Cold water in summer can appear at the sea surface only when there is wind larger than a minimum wind impulse of order $10m^2/sec$.

• Korean Journal of Environmental Biology
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• v.17 no.2
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• pp.209-215
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• 1999

Changes of malate dehydrogenase isozyme in oyster exposed to different temperature, pH and salinity were investigated by polyacrylamide gel electrophoresis. MDH isozyme in control group was separated into two bands on the positive side. In case of temperature and pH stress, MDH isozyme was separated into only one band after 12 hours exposure but two bands after 24, 48 hours exposure on the positive side. In case of salinity stress, after 12 hours exposure, MDH isozyme bands were separated into two bands in 5 ppt, 30 ppt and three bands in 10 ppt, 40 ppt concentration on the positive side. After 24 hours and 48 hours exposure case in salinity stress, MDH isozyme bands was separated into two bands on the positive side in all concentration. Activities of isozyme bands show their characteristics according to the condition of experiment. In conclusion, changes of MDH isozyme was a biochemical defense mechanism in oyster and result from effect of environmental stress to oyster.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.6
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• pp.249-256
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• 2008

The durability of marine concrete structure is severely degraded by corrosion due to penetration and diffusion of chloride. So, many researches have been performed to improve the durability in marine concrete structure. In this study, the concrete members mixed with the mineral admixtures(SF and BFS), the epoxy-coated steel, and corrosion inhibitors are prepared, and four-point bending test of specimens are performed to investigate the flexural behaviors and the applicability for marine concrete structure. From the test results, the mineral admixtures and inhibitors are useful for safety against the initial cracking and the bending resistance in specimens. When the durable material is used in specimen, the tensile stress of reinforcing rod was less variable in same bending span length, and the durable member showed a stable behavior. And it is evaluated that the crack spacing is not larger in specimen used the durable material.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.1-6
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• 1984

The three kinds of Kochujang were prepared with liquid koji equivalent to 30%, 50%, and 70% of brewing water. The qualities of the Kochujangs during aging at $25^{\circ}C$ for 4 months were compared with those of the control group which was made from solid koji. There were no significant differences in the contents of moisture, crude protein, crude fat, NaCl and ethyl alcohol between test groups. The contents of amino nitrogen, soluble nitrogen, reducing sugar and pH of each test group during Kochujang aging were high in the order of control group. 70% liquid koji group, 50% liquid koji group and 30% liquid koji group. The pH of control group was over 5.0 during aging period. The titratable acidity of Kochujang was high in the 50% liquid koji group and the 30% liquid koji group.

• Journal of the Korean Society of Marine Environment & Safety
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• v.11 no.1 s.22
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• pp.77-82
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• 2005

In order to investigate the initial stage of deep water formation between Vladivostok and the subpolar front in the East Sea, the factors, temperature, salinity, dissolved oxygen, measured by multi-ship surveys in ]969 have been used. Deep water formation in the .cast Sea occurs in essentially two different forms: near continent and open ocean formation. The position of eddy derived from potential vorticity matches well with that of deep water formation. The vertical and horizontal distributions of potential vorticity, geostrophic current, temperature, salinity and dissolved oxygen give clues for the preconditioning phase qf open ocean formation like a doming of isotherm, associated with a cyclonic circulation.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.384-388
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• 1988

A marine bacterium Achromobacter sp. M-1220 was isolated from enrichment culture for emulsification of Bunker-C oil. The bacterium can emulsify approximately 7.5g of Bunker-C oil per liter in sen water medium within 1 drys at 18$^{\circ}C$ and multiply from 8$\times$10$^5$ cells to 9$\times$10$^9$ cells per mi. Optimum pH and salt concentration were pH 7.5 and 3% for the emulsification of Bunker-C oil. Emulsification takes place actively in both high sulfur-containing Bunker-C oil and high sulfur-con-taming crude oil. The amount of emulsification depends on the exogenous addition of nitrogen and phosphate sources. The bacterium can also utilize n-hexndecane, n-paraffin me benzene among the petroleum compounds as a sole carbon source.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.6
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• pp.830-837
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• 2016

Juvenile Anoplopoma fimbria (mean length $15.6{\pm}1.4cm$, mean weight $68.7{\pm}4.3g$) were exposed to 4 months with the different levels of salinity [100 (35.0), 90 (31.5), 80 (28.0), 70 (24.5), 60 (21.0), 50 (17.5), and 40 (14.0) % (psu)] for 4 months. Hematological parameters such as red blood cell (RBC) counts, hematocrit (Ht), and hemoglobin (Hb) concentrations were substantially decreased under salinities of 50% psu or lower. Of the measured inorganic plasma constituents, magnesium was notably decreased, whereas there was no effect on calcium. Among organic plasma components, glucose and cholesterol were significantly increased, and total protein was decreased. Among enzyme plasma components, glutamic oxalate transaminase (GOT), glutamic pyruvate transaminase (GPT), and alkaline phosphatase (ALP) were significantly increased under salinities of 50% psu or lower. Antioxidant responses such as glutathione S-transferase (GST) and glutathione (GSH) were significantly decreased at salinities of 50% psu or lower. The results of this study indicate that salinity affects the blood parameters, plasma constituents, and antioxidant responses of A. fimbria.

• Journal of the Korea Concrete Institute
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• v.23 no.1
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• pp.23-30
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• 2011

In this study, deterioration degrees of concrete were investigated at laboratory under seawater attack and cycling freeze-thaw, which are major durability performance deterioration factors of concrete. Deteriorations of mixed concrete using Portland & blended cement were examined by instrumental analysis of changes in relative dynamic modulus of elasticity and compressive strength. After 520 cycles of freeze-thaw, relative dynamic modulus of elasticity and compressive strength of concrete mixed with normal Portland and LHC over 75% showed relatively low resistance of approximately 44% of those values of SRC. Concrete replaced with 50% fine powder of blast furnace slag showed the most excellent freeze-thaw resistance among the tested blended cement concrete.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.467-473
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• 2015

In the present study, we investigated the physical characteristics of ground water behaviors and sediment properties in intertidal flat of Nakdong River Estuary. Variations in level and temperature of the groundwater depended on tides. And increase of river discharge led to increase in groundwater level and decrease in ground salinity at a depth of several ten cm. Difference in permeability of the intertidal flat sediments due to content of fine fraction affect velocity of groundwtaer level decrease at low tide. Furthermore, enhancement of groundwater flow due to the increase in permeability leaded to decrease of fine fraction in the intertidal flat sediments.