• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.5
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• pp.787-807
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• 2018

When conducting the underground safety impact assessment under the special law in Korea, it is essential to investigate the occurrence of underground cavities. When underground cavities were discovered, the underground safety was assessed through numerical analysis. The previous study has suggested the stability evaluation based on the factor of safety by changing the 2D shape of the small underground cavity. In this study, the effects of small underground cavities considering 3D shapes were examined using a continuum analysis program and compared with the 2D results presented in previous study. If the 3-Dimensional shape of the underground cavity is found close to the sphere type, it would be reasonable to evaluate the factor of safety by the shear strength reduction method regardless of the size and position of the cavity. If a high-aspect ratio underground cavity with a depth of 2 m or more from the ground surface and an aspect ratio (a/b) of 2.0 or more is in the vertical direction, not only the factor of safety but the failure mode shape should be cautions in the stability evaluation using the shear strength reduction method. The results of this study are expected to be basic data on underground safety impact assessment.

• Journal of the Mineralogical Society of Korea
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• v.31 no.2
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• pp.123-135
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• 2018

This study tried to find the clue to Seokrok province by comparing Seokrok used in painting culture properties with Seokrok ore from domestic occurrence and imported Seokrok ore. To this end, chemical and mineralogical characteristics of painting cultural properties were identified with portable X-ray Florescence (p-XRF), micro X-ray diffraction (micro XRD) and SEM/EDS Analysis. To obtain Pb isotopic ratio, the Pb contained in Seokrok has been analyzed with Thermal Ionization Mass Spectrometer. Atacamite (or botallackite) and small quantity of brochantite were identified from Seokrok in Dancheong, and malachite was also identified from Buddhist painting besides those two ingredients. Without distinction of type, most Seokrok used in painting cultural properties is atacamite composed of Cu and Cl. From Pb isotope analysis, it was found that Seokrok in painting cultural properties was closer to that of north Korea, north China and Japan than south Korea as in regional division for East North Asia suggested by Mabuchi. The Pb isotopic ratio of domestic green mineral belongs to the distribution of Seokrok inside the painting cultural properties but imported malachite showed considerably difference. Considering the fact that atacamite, the main mineral of Seokrok in painting cultural properties is rarely produced from southern mine of the Korean Peninsula and the result of Pb isotope analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.17-25
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• 2017

Owing to recent climate change, the scale of rainfall tends to increase gradually and the risk of flooding has increased. Therefore, the importance of improving the levee management and disaster response is increasing. Levee management in Korea is carried out at the level of damage recovery after the occurrence of damage. Therefore, it is necessary to develop a technology for predicting and managing the levee safety with proactive river management. In this study, a method to estimate the safety against erosion and overflow was suggested. A map of levee safety that can be used as basic data is presented by displaying the levee safety on the map. The levee erosion safety was calculated as the ratio of the internal and external force for each shore type. The levee overflow safety was calculated as the ratio of the maximum conveyance and design flood. The maximum conveyance was a discharge when the level of the river was equal to the level of the levee crown. The levee safety was classified into 5 grades: very safe, safe, normal, dangerous, and very dangerous. As a research area from downstream of Nam River Dam to Nakdong River Junction, the levee safety against erosion and overflow was estimated for all levees and all cross-sections of the river. The levee safety was displayed on a map using GIS. Through the levee safety map as a result of this study, the levee safety can be observed intuitively. Using the levee safety map, a maintenance plan for a river can be easy to build. This levee safety map can be used to help determine the priority of investment for efficient budget used.

• Toxicological Research
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• v.22 no.4
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• pp.357-364
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• 2006

This study was undertaken to develop a reliable mice model demonstrating similar immunologic phenomena as human atopic dermatitis characterized with predominance of type-2 immune response. BALB/C mice and NC/Nga mice were sensitized twice with $100{\mu}l$ of 1% 2,4-dinitrochlorobenzene (DNCB) or vehicle (acetone : olive oil=4:1 mixture) in a week and challenged twice with $100{\mu}l$ of 0.2% DNCB or the vehicle at the following week. Mice were sacrificed at 19 days following the second DNCB or vehicle challenge for NC/Nga mice and at 28 days following the second DNCB or vehicle challenge for BALB/c mice. Upregulation of plasma 1gE, a hallmark of atopic dermatitis occurrence, was evident in the plasma obtained 4 day after the second DNCB challenge from BALB/c mice (approximately 4-fold) and NC/Nga mice (approximately 6-fold) treated with DNCB in comparison with that of the vehicle treated-control mice, and remain higher $3{\sim}4$ week after the second challenge. Ratio of plasma IgG1 versus IgG2a concentration was significantly higher in the mice treated with DNCB than the control mice, which also implies the skewed type-2 reactivity in vivo. Ratio of interleukin-4 versus interferon gamma produced in the splenic T cell culture supernatants was approximately 3-fold higher in the both strains of mice treated with DNCB than their control mice, respectively. The DNCB-treated mice demonstrated atopic dermatitis-like skin legions characterized with erythma, scaling, and hemorrhage, which was not observed with the control mice. Scratching on face or dorsal area was significantly more frequent (approximately 25-fold) in the DNCB-treated mice than the control at next day of the second DNCB challenge, and scratching frequency remains higher (approximately 4-fold) in the mice treated with DNCB than the control at 14 day following the second DNCB challenge. Overall, the mice model developed through sensitization and challenge with DNCB may be useful for research on atopic dermatitis and development of treatment materials for atopic dermatitis.

• Journal of Mushroom
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• v.13 no.3
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• pp.223-227
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• 2015

The study was conducted to investigate the effects of post-incubation period and temperature treatment conditions during incubation on the uniform primordia formation and cultural characteristics of oyster mushroom (Pleurotus ostreatus). Three kinds post-incubation period; 25, 30, 35 days and control were applied for 30 days while two kinds incubation room temperature $23^{\circ}C$ and $26^{\circ}C$ and control were used $20^{\circ}C$. The substrate temperature during pre-incubation was of 'Suhan No. 1' and 'Gonji No. 7'. Oyster mushroom varieties tended to increase between $24^{\circ}C$ to $26^{\circ}C$ at 11 to 15 days after inoculation and then they were maintained in treatment temperature during post -incubation period. The $CO_2$ occurrence was at the highest at 6,500 ppm for 'Suhan No. 1' and 5,800 ppm for 'Gonji No. 7' at the time of the highest temperature increase. The ratio of un-uniformal primordia formation and the ratio of non-commercial fruit body were reduced by 40%, 10.5%, respectively compared to control for 'Suhan No. 1' when in the post-incubation temperature was $26^{\circ}C$, and incubated for 10 days and 15 days treatment. Also, 'Gonji No. 7' was reduced by 19%, 9.5%, respectively when in the post-incubation temperature was $26^{\circ}C$, and incubated for 10 days treatment. Therefore, the higher post-incubation temperature of room and longer post-incubation period resulted in the higher percentage of primordia formation of two cultivars.

• Economic and Environmental Geology
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• v.29 no.4
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• pp.421-428
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• 1996

The occurrence, optical property, chemical composition, crystal structure and formation environments of the phillipsite within deep-sea manganese nodules were systematically investigated in this study. Phillipsite in manganese nodules occurs in nucleus of nodules along with consolidated bottom sediments, weathered volcanic debris, and interstitial grains in the each layer of manganese encrusts. Phillipsite is predominantly pseudomorphs of volcanic shards, and occurs as white to pale yellow in color lath-shaped and equant crystals. These show aggregations of prismatic, blocky, and bladed of 2 to $20{\mu}m$ long, and 2 to $5{\mu}m$ thick. The simplified average chemical formula of phillipsite is $({Ca_{0.1}Mg_{0.3}Na_{1.1}K_{1.5}})_3{(Fe_{0.3}Al_{4.2}Si_{11.8})O_{32}{\cdot}10H_2O}$ with a very siliceous and alkalic. The $Si/(Al+Fe^{+3})$ ratio is 2.37 to 2.78 and alkalis greatly exceed the divalent exchangeable cations, and Na/K ratio is 0.59 to 0.81. The phillipsite is monoclinic ($P2_l/m$) with the unit-cell parameters, $a=10.005{\AA}$, $b=14.129{\AA}$, $c=8.686{\AA}$, ${\beta}=124.35^{\circ}$, and $V=1013.6{\AA}^3$. Phillipsites in manganese nodules formed apparently authigenically at a temperature less than $10^{\circ}C$, and they crystallized at a pressure of less than 0.7 kb, and pH of about 8 in deep-sea environments.

• Fisheries and Aquatic Sciences
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• v.23 no.4
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• pp.7.1-7.8
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• 2020

Background: To minimize the use of antibiotics and to obtain a more sustainable fish culture and aquaculture industry, development of alternative natural source of immunostimulant to replace antibiotic in aquafeed is highly needed. Objective: Dietary inclusion effect of yacon (YC), ginger (GG), and blueberry (BB) on growth, body composition, and disease resistance of black rockfish against Vibrio anguillarum was compared to ethoxyquin (EQ). Methods: Four hundred eighty juvenile (an initial weight of 4.2 g) fish were randomly distributed into 12 of 50 L flowthrough tanks (forty fish per tank). Four experimental diets were prepared; the control (Con) diet with 0.01% EQ inclusion, and YC, GG, and BB diets at 1% each additive inclusion. Each additive was included into the experimental diets at the expense of wheat flour. Each diet was assigned to triplicate tanks of fish and hand-fed to satiation twice daily for 8 weeks. At the end of 8-week feeding trial, 20 fish from each tank fish were artificially infected by intraperitoneal injection with 0.1 mL of culture suspension of pathogenic V. anguillarum containing 3.3 × 10⁶ cfu/mL respectively. Fish were monitored for the following 8 days after V. anguillarum infection and dead fish were removed every 6 h for the first 4 days and 12 h for the rest of the study. Results: Weight gain, specific growth rate (SGR), and feed efficiency ratio (FER) of fish fed the YC diet was higher than those of fish fed all other diets. However, feed consumption, protein efficiency ratio, and protein retention was not affected by dietary additive. Moisture, crude protein, and crude lipid content of the whole body of fish were affected by dietary additive. Analysis of the Kaplan-Meier survival curves showed that survival of fish fed the YC, BB, and GG diets was higher than the Con diet. Conclusion: Oral administration of YC can improve not only weight gain, SGR, and FER of black rockfish, but lower mortality of rockfish at occurrence of V. anguillarum.

• Journal of the Korean GEO-environmental Society
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• v.14 no.6
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• pp.13-19
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• 2013

In this study, the target ground was selected for the assessment of liquefaction, for which energy-based Arias intensity liquefaction assessment method was applied, The results of evaluation by simplified method using conventional in-situ test were compared. The result of the assessment of liquefaction revealed that the safety factor of the Arias Intensity using the actual records of the Hachinohe and Ofunato earthquake showed generally similar trends with the simplified method, However, the Arias Intensity factor of safety for the artificial earthquake created from the design response spectrum showed some difference from the factors of safety of the simplified method. The shear stress ratio and the occurrence strength of the Arias Intensity are differently calculated between stress and energy, but the resistance stress ratio of the simplified method and the resistance strength of the Arias Intensity use the empirical chart of the results of the standard penetration test for the actual liquefaction areas by the earthquake, which seems the reason for the similar results between Arias Intensity assessment and stress concept simplified method for Hachinohe and Ofunato earthquakes. Therefore, it was found that the energy-based Arias Intensity liquefaction assessment could represent the dynamic changes of the ground caused by seismic characteristics such as acceleration, magnitude, duration and amplitude.

• The Journal of the Petrological Society of Korea
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• v.17 no.3
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• pp.154-165
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• 2008

Rock bowls and pots used in restaurants are one of the popular usages of natural rocks in Korea. Most rock bowls and pots are made of Mg- and Ca-rich amphibolite composed of hornblende, actinolite, tremolite, diopside, plagioclase. Hornblende occurs as prismatic crystal habit, and belongs to Mg-hornblende to tschermakite. Actinolite and tremolite occur as acicular form (aspect ratio $0.10{\sim}0.13$), and ranges 0.65 to 0.90 in Mg/(Mg+Fe) ratio. These acicular actinolite and tremolite are non-asbestos minerals. However to use of rocks containing these minerals as tableware it is needed to regulatory guidelines for stability and utility based on petrological and mineralogical characteristics. Discrepancy of rock occurrence and mineral chemistry between commercial rock bowls and original rocks indicate that most rock bowls are made of uncertain amphibolite in original location. Consequently, there is a potential risk to use inappropriate amphibolites as tableware. Therefore, it is needed to systematically research on geology and biology, and manage commercial rock bowls and pots used in Korean restaurants.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.413-422
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• 1997

To know the food chain of an intertidal community, feeding habits of Acanthogobius elongata were studied by analyzing stomach contents. A. elongata were monthly collected and the environment conditions of the habitat were investigated in the intertidal zone of Naecho-do, Kunsan from July 1993 to June 1994. Ratio of stomach contents to weight of A. elongata was $1.78\%$, and fullness of stomach showed a similar value to ratio of stomach contents to weight. Fullness of stomach was increased twice a day in the morning and the afternoon. The most important food item was copepods amounting to $54\%$ of the total stomach contents. Of these, Paracalanus parvus was most abundant in spring, Calanus sinicus in summer, Acartia sp. in autumn, and Calanus sinicus in winter. Degree of overlapping for the food items between seasons was not very high, except between spring and summer. There were little differences in feeding habits among the size groups. For all size groups of A. elongata, the occurrence rates of copepods, decapods, molluscs and cirriped larvae were high. As the fish grows, those of amphipods, polychaete larvae, isopods, cumaceans and stomatopods increased gradually. The importance index of the major food items was in the order of Calanus sinicus, Corycaeus affinis and Acartia sp..