• Korean Journal of Soil Science and Fertilizer
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• v.10 no.1
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• pp.69-74
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• 1977

This study has been conducted to identify physico-chemical and clay mineralogical characteristics of bentonites produced in Korea for the purpose of finding good quality bentonite for agricultural ure. The results are summarized as follows: 1. Bentonites are mainly composed of montmorillonite developed from tuffs in a lava flow. 2. Chemical properties of bentonites are: pH in $H_2O$(1:1), 7:cation exchange capacity, 60-96me/100g; content of $SiO_2$, 54-72%; ratio of $SiO_2$ to $Al_2O_3$, 4.1-10.0;oven dry loss of $H_2O$ is higher than the ingnition loss of $H_2O$. 3. The x-ray diffrection patterns of powder bentonites show peaks at $14-15{\AA}$, $4.4{\AA}$, and $2.5{\AA}$, and that of swellen one show $17{\AA}$ when treated with ethylene glycol. 4. Distribution areas of the good quality bentonites were (1) Dogu-Dong, Donghae-Myeon, Yeonil-Gun, Gyeongsangbug-Do (2) Hamyeon-Ri, Yangnam-Myeon, Weolseong-Gun, Gyeongsanbug-Do. (3) Joam-Ri, Gangdong-Myeon, Weolseong-Gun, Gyeongsangbug-Do. (4) Sanha-Ri, Gangdong-Myeon, Ulju-Gun, Gyeongsangnam-Do. (5) Sinhyeon-Ri, Gangdong-Myeon, Ulju-Gun, Gyeongsangnam-Do. (6) Yonghang-Ri, Pyeongchang-Myeon, Pyeongchang-Gun, Gangweon-Do.

• Journal of the Korean School Mathematics Society
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• v.20 no.4
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• pp.445-464
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• 2017

This study targeting 10 high school 3rd grade students who have studied space figures in natural sciences track analyzes the process of analogical discovery from the construction of inscribed and circumscribed circles of a triangle to that of inscribed and circumscribed spheres of a tetrahedron through the analytical method using Geogebra. The subjects are divided into two groups of five, the experimental group consisting of those who have experienced analytical method and the comparative group consisting of those who haven't. This research analyzing the process of constructing inscribed and circumscribed spheres of a tetrahedron. Although students of both groups all have an accurate preliminary knowledge of inscribed and circumscribed circles of a triangle, they have difficulty in constructing inscribed and circumscribed spheres of a tetrahedron. However, the students of experimental group who have studied the constructing process of inscribed and circumscribed circles of a triangle in reverse using analytical method and Geogebra can perform analogical discovery finding out the way to construct inscribed and circumscribed spheres of a tetrahedron using analogy by themselves. They can control and explore space figures by visualization. Also, they can immediately examine and provide feedback on the analogizing process of their own. In addition, the process affects the attitude of students toward mathematics positively as well as gives validity to the result of analogy.

• Journal of the Korean Arthroscopy Society
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• v.9 no.2
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• pp.194-200
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• 2005

Purpose: To evaluate the short-term follow up outcome and the effectiveness of arthroscopic vertical shift of anteroinferior capsulolabral complex, plication of AIGHLC (anterior band of inferior glenohumeral ligament complex) and thermal capulorraphy, posteroinferior suture plication, rotator interval closure as an adjuncts in recurrent instability of megafrequency with night time dislocation. Materials & Methods: From March 1998 to February 2004, we have had 18 shoulders out of 156. All of the cases have been night time dislocation above more one time. The age were average 29.4$(21{\sim}37)$ year old. The average follow up were 21.1 $(12{\sim}45)$months We checked Rowe score and ROM at pre-operation, post-operation 6 months,1 year & last follow up period. Results: Above good results were 16 cases(88.9%). The excellent were 6 cases, good were 10, fair 1, poor 1. Conclusions: In recurrent anterior shoulder dislocation in greater than 50 frequency, arthroscopic stabilization can be an alternative technique for selected patients against open inferior capsular shift. But more long ter n follow up and large materials will be needed in the future study.

• The Korean Journal of Pain
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• v.12 no.2
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• pp.177-182
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• 1999

Background: Clonidine, an ${\alpha}_2$ adrenergic agonist blocks nerve conduction. However, in our previous experiment we found that adrenaline neither blocks nerve conduction by itself nor augment nerve conduction blockade by lidocaine near clinical concentrations. Possible explanations are: 1) there may be antagonism between some of adrenergic receptors, 2) clonidine may block nerve conduction via non-adrenergic mechanism. The purpose of this study is to obtain dose-response curves of several different forms of adrenergic receptor agonist to see the relative potencies of each adrenergic receptors to block nerve conduction. Methods: Recordings of compound action potentials of A-fiber components (A-CAPs) were obtained from isolated sciatic nerves of adult male Sprague-Dawley rats. Nerve sheath of the sciatic nerve was removed and desheathed nerve bundle was mounted on a recording chamber. Single pulse stimuli (0.5 msec, supramaximal stimuli) were repeatedly applied (2Hz) to one end of the nerve and recordings of A-CAPs were made on the other end of the nerve. Dose-response curves of epinephrine, phenylephrine, isoproterenol, clonidine were obtained. Results: $ED_{50}$ of each adrenergic agonist was: $4.51\times10^{-2}$ M for epinephrine; phenylephrine, $7.74\times10^{-2}$ M; isoproterenol, $9.61\times10^{-2}$ M; clonidine, $1.57\times10^{-3}$ M. Conclusion: This study showed that only clonidine, ${\alpha}_2$ adrenergic agonist, showed some nerve blocking action while other adrenergic agonists showed similar poor degree of nerve blockade. This data suggest that non-effectiveness of epinephrine in blocking nerve conduction is not from the antagonism between adrenergic receptors.

• Korean Journal of Remote Sensing
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• v.36 no.2_1
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• pp.217-229
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• 2020

Recently, weather changes in Korea have intensified due to global warming, and the five major natural disasters that occur mostly include heavy rains, typhoons, storms, heavy snow, and earthquakes. Busan is vulnerable to snow disaster, given that the amount of natural disaster damage in Busan accounts for more than 50% of the total amount in the entire metropolitan cities in Korea, and that the Busan area includes many hilly mountains. In this study, we attempted to identify vulnerable areas for snowfall disasters in Busan areas using the geographic information system (GIS) with the data for both geographical and anthropogenic characteristics. We produced the maps of vulnerable areas for evaluating factors that include altitude, slope, land cover, road networks, and demographics, and overlapped those maps to rank the vulnerability to snowfall disasters as the 5th levels finally. To weight each evaluating factor, we used an entropy method. The riskiest areas are characterized by being located in mountainous areas with roads, including Sansung-ro in Geumjeong-gu, Mandeok tunnel in Buk-gu, Hwangnyeongsan-ro in Suyeong-gu, and others, where road restrictions were actually enforced due to snowfall events in the past. This method is simple and easy to be updated, and thus we think this methodology can be adapted to identify vulnerable areas for other environmental disasters.

• The Journal of Engineering Geology
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• v.28 no.2
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• pp.193-206
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• 2018

In this study, as part of the "Small-scale $CO_2$ Injection-Demonstration Project in Offshore Pohang Basin", we performed drilling and completion of a $CO_2$ injection well from the offshore platform installed in the Yeongil Bay, Pohang city, Gyeongsang buk-do. The drilling of injection well was carried out from an offshore platform installing on the sediment formations of the Pohang Basin. Drilling diameters were reduced by stages, depending on the formation pressure and groundwater pressure along a depth and the casing installation and cement grouting in drilled hole were performed at each stage. The injection well was drilled to a final depth of 816.5 m with a hole diameter of 4 7/8 inches (${\Phi}124mm$) and the perforated casing for an injection section was installed in a depth of 746.5~816.5 m. Injection tubing, packer, and christmas tree were installed for the completion of an injection well for $CO_2$. The validation project of the $CO_2$ injection was accomplished successfully by drilling the injection well and installing the injection facilities, and through the suitable $CO_2$ injection process. The current injection facility is a facility for small-scale injection demonstration of 100 tons. In the case of large-scale demonstration facility test of a capacity of 10,000 tons, research is underway through the upgrading of the injection facilities.

• The Korean Journal of Community Living Science
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• v.17 no.4
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• pp.39-48
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• 2006

This study was carried out to make a search for the usefulness of marigold plants (Tagetes erecta) as a natural dye. And we have also examined into the dyeability and antifungal activity of silk and cotton fabrics dyed with 2% powdered colorant and 1% liquid colorant. Almost surface colors of silk and cotton fabrics dyed with 2% powdered colorant and that dyed with 1% liquid colorant except for that treated Cu and Fe with mordants were shown by Y-level. $L^*$ values of silk fabrics dyed with 2% powdered colorant were 66.2 to 86.39, those $a^*$ values were -1.97 to 6.09, and those $b^*$ values were 13.69 to 35.97. And $L^*$ values of cotton fabrics dyed with 2% powdered colorant were 78.97 to 89.62, those a values were -3.39 to 0.38, and those $b^*$ values were 5.63 to 15.61 $L^*$ values of silk fabrics dyed with 1% liquid colorant were 34.37 to 85.57, those a values were -7.79 to 12.33, and those $b^*$ values were 15.13 to 82.91, And $L^*$ values of cotton fabrics dyed with 1% liquid colorant were 44.12 to 87.90, those $a^*$ values were -8.37 to 6.18, and those $b^*$ values were 11.65 to 78.87. Colorfastness of silk fabrics against light treated nothing with mordants and that dyed with 1% liquid colorant decreased for a little by second grade, however, that against washing, rubbing, perspiration and dry cleaning were increased over fourth grade. Colorfastness of cotton fabrics in terms of rubbing, light, and dry cleaning, except for washing and perspiration, were shown by over third grade, when that was treated nothing with mordants. Antifungal activities of silk fabrics treated nothing with mordants and dyed with 1% liquid colorant of marigold extracts were shown by 28.9% against Staphylococcus aureus. However, those of Al, Ca, Cu and tartaric acid mordanting were more than 25.5% against Staphylococcus aureus and Klebsiella pneumoniae.

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.917-930
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• 2017

This study was conducted to evaluate Raphanus sativus extracts to methane reduction in rumen. Five different levels of R. sativus extracts were used to investigate the most effective dosing level for the decrease of methane production in the rumen. The rumen fluid was collected from a cannulated one Hanwoo cow ($BW=450{\pm}30kg$) consuming 600 g/kg timothy and 400 g/kg concentrate. On fermentation day, rumen fluid was collected at 2 hr postfeeding R. sativus extracts was dosed to achieve final concentration of 0, 1, 3, 5, 7, and 9% respectively, to fermentation bottles containing the mixture of rumen fluid and McDougall's buffer and 300 mg of timothy was added as a substrate. The fermentation was conducted for 3, 6, 9, 12, 24, 48 and 72 hr incubation time at $39^{\circ}C$ with shaking. In vitro ruminal pH values were measured normal range for ruminal fermentation. Dry matter disappearance was significantly higher (p<0.05) at 3 hr incubation time 1, 3 and 5% doses than that of control. The highest methane reduction was observed in 12 hr incubation time 5, 7 and 9%. The carbon dioxide emission was also significantly (p<0.05) lower than that of control at 12 hr incubation time 5, 7 and 9%. The total volatile fatty acid was no significant difference between control and all doses level at 12 and 24 hr incubation time. At 24 hr incubation time, the result of real-time PCR were indicated that M. archea was significantly lower (p<0.05) at all doses level comparing to that of control. In conclusion, R. sativus extracts were significantly decreased methane emission. R. sativus extracts were significantly lower (p<0.05) than that of control at 12 hr incubation time 5, 7 and 9% and no adversely effect in rumen pH, dry matter disappearance and total VFA.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.2
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• pp.168-174
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• 1992

This study was carried out to find out the distribution of soil components and their relationships in layer of soil profiles under upland condition. Concentrations of nitrate, chloride, and that sort of thing in soil profiles were tested in a field covering $235m^2$ by core sampling down to 150cm depth. Total nitrogen contents in soil profiles progressively decreased in lower depths down to 150cm. Nitrate concentrations in deeper layers than 110cm, which revealed a similar distribution pattern with total nitrogen down to 110cm, increased with the depth lowering to 150cm, indicationg that nitrate has leached to deep layer. Natural abundance of $^{15}N$ in total nitrogen and nitrate in all the soil profiles showed higher values compared with the other general cultivated soils and trended to get higher in deeper layers. The horizontal variation of $^{15}N$ distribution in the field surveyed was not significant. Chloride concentrations and EC values in soil profiles increased with depth where nitrate was accmulated, and showed a highly positive correlation between them.

• Journal of Bio-Environment Control
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• v.18 no.1
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• pp.60-66
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• 2009

This study was conducted to investigate into the effective drying method for three greens such as bang-a (Isodon japonicus), aster (Aster yomena) and lettuce greens (Ixeris dentata) Nakai. We have dried three greens using the different drying methods, have made methanol extracts and have also determined the physiological activities in $1,000mg{\cdot}L^{-1}$ extracts. Total phenolic compound contents were most increased by 65.1 and $60.2mg{\cdot}L^{-1}$ in the extracts of bang-a and aster which were frozen dried, however, that in lettuce greens were oven dried by $51.2mg{\cdot}L^{-1}$. Total flavonoid contents were extremely much more in bang-a extracts dried in the oven by $70.6mg{\cdot}L^{-1}$, however, aster and lettuce greens extracts frozen dried by 53.9 and $35.8mg{\cdot}L^{-1}$. DPPH radical scavenging activity in bang-a extracts were greatly increased by 78.8% when bang-a were frozen and dried, however, that in aster were not significant by $89.8{\sim}90.9%$. DPPH radical scavenging activities in lettuce greens extracts were became highest in the order f oven drying (91.9%), natural drying (91.0%) and freeze drying methods (90.9%). Nitrite radical scavenging activities in bang-a and aster extracts were most increased in the natural drying treatment by 73.3 and 78.2%, however, that in lettuce greens extracts were highest in freeze drying treatment by 75.1%.