• Economic and Environmental Geology
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• v.15 no.3
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• pp.123-154
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• 1982

Petrochemical, K-Ar dating, Sand Rb/Sr isotopes, metallogenic zoning, paleomagnetic and geotectonic studies of the Gyongsang basin were carried out to examine applicability of plate tectonics to the post-late Cretaceous igneous activity and metallogeny in the southeastern part of Korean Peninsula. The results obtained are as follows: 1. Bulgugsa granitic rocks range from granite to adamellite, whose Q-Ab-Or triangular diagram indicates that the depth and pressure at which the magma consolidated increase from coast to inland varying from 6 km, 0.5-3.3 kb in the coastal area to 17 km, 0.5-10 kb in the inland area. 2. The volcanic rocks in Gyongsang basin range from andesitic to basaltic rocks, and the basaltic rocks are generally tholeiitic in the coastal area and alkali basalt in the inland area. 3. The volcanic rocks of the area have the initial ratio of Sr^{87}/Sr^{86} varying from 0.706 to 0.707 which suggests a continental origin; the ratio of Rb/Sr changing from 0.079-0.157 in the coastal area to 0.021-0.034 in the inland area suggests that the volcanism is getting younger toward coastal side, which may indicate a retreat in stage of differentiation if they were derived from a same magma. The K_2O/SiO_2 (60%) increases from about 1.0 in the coastal area to about 3.0 in the inland area, which may suggest an increase indepth of the Benioff zone, if existed, toward inland side. 4. The K-Ar ages of volcanic rocks were measured to be 79.4 m.y. near Daegu, and 61.7 m.y. near Busan indicating a southeastward decrease in age. The ages of plutonic rocks also decrease toward the same direction with 73 m.y. near Daegu, and 58 m.y. near Busan, so that the volcanism predated the plutonism by 6 m.y. in the continental interior and 4 m.y. along the coast. Such igneous activities provide a positive evidence for an applicability of plate tectonics to this area. 5. Sulfur isotope analyses of sulfide minerals from 8 mines revealed that these deposits were genetically connected with the spacially associated ingeous rocks showing relatively narrow range of ${\delta}^{34}S$ values (-0.9‰ to +7.5‰ except for +13.3 from Mulgum Mine). A sequence of metallogenic zones from the coast to the inland is delineated to be in the order of Fe-Cu zone, Cu-Pb-Zn zone, and W-Mo zone. A few porphyry type copper deposits are found in the Fe-Cu zone. These two facts enable the sequence to be comparable with that of Andean type in South America. 6. The VGP's of Cretaceous and post Cretaceous rocks from Korea are located near the ones($71^{\circ}N$, $180^{\circ}E$ and $90^{\circ}N$, $110^{\circ}E$) obtained from continents of northern hemisphere. This suggests that the Korean peninsula has been stable tectonically since Cretaceous, belonging to the Eurasian continent. 7. Different polar wandering path between Korean peninsula and Japanese islands delineates that there has been some relative movement between them. 8. The variational feature of declination of NRM toward northwestern inland side from southeastern extremity of Korean peninsula suggests that the age of rocks becomes older toward inland side. 9. The geological structure(mainly faults) and trends of lineaments interpreted from the Landsat imagery reveal that NNE-, NWW- and NEE-trends are predominant in the decreasing order of intensity. 10. The NNE-trending structures were originated by tensional and/or compressional forces, the directions of which were parallel and perpendicular respectively to the subduction boundary of the Kula plate during about 90 m.y. B.P. The NWW-trending structures were originated as shear fractures by the same compressional forces. The NEE-trending structures are considered to be priginated as tension fractures parallel to the subduction boundary of the Kula plate during about 70 m.y. B.P. when Japanese islands had drifted toward southeast leaving the Sea of Japan behind. It was clearly demonstrated by many authors that the drifting of Japanese islands was accompanied with a rotational movement of a clock-wise direction, so that it is inferred that subduction boundary had changed from NNE- to NEE-direction. A number of facts and features mentioned above provide a suite of positive evidences enabling application of plate tectonics to the late Cretaceous-early Tertiary igneous activity and metallogeny in the area. Synthesizing these facts, an arc-trench system of continental margin-type is adopted by reconstructing paleogeographic models for the evolution of Korean peninsula and Japan islands. The models involve an extention mechanism behind the are(proto-Japan), by which proto-Japan as of northeastern continuation of Gyongsang zone has been drifted rotationally toward southeast. The zone of igneous activity has also been migrated from the inland in late-Cretaceous to the peninsula margin and southwestern Japan in Tertiary.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.286-296
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• 2014

In this study, we investigated the macrobenthic community structure and spatiotemporal variations in Uljin Marine Ranching area, East Sea of Korea. Macrobenthos were collected using a modified van Veen grab sampler from April to September 2013. Total number of species sampled was 345 and mean density was 5,797 ind. $m^{-2}$, both of which were dominated by the polychaetes. The most dominant species were Spiophanes bombyx (53.64%), followed by Magelona sp.1 (6.96%), Cadella semitorta (2.73%), Lumbrineris longifolia (2.16%) and Alvenius ojianus (2.08%). Cluster analysis and nMDS ordination analysis based on the Bray-Curtis similarity identified 2 station groups. The group 1 (station 2, 3, 5, 6, 8 and 9) was characterized by high abundance of the polychaetes Magelona sp.1, Lumbrineris longifolia, Scoloplos armiger, Praxillella affinis, Maldane cristata and the bivalve Alvenius ojianus, with fine sediment above 30m water depth. On the other hand, the group 2 (station 1, 4, 7 and 10) was numerically dominated by the polychaete Lumbrineriopsis sp. and the bivalve Cadella semitorta, with coarse sediment below 5m water depth. Collectively, the macrobenthic community structure showed a distinct spatial trend, which seemed to be related to the water depth and sediment composition.

• Journal of Sensor Science and Technology
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• v.7 no.3
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• pp.154-162
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• 1998

A planar Bi-Sb multijunction thermal converter with high thermal sensitivity and small ac-dc transfer error has been fabricated by preparing the bifilar thin film Pt-heater and the hot junctions of thin film Bi-Sb thermopile on the $Si_{3}N_{4}/SiO_{2}/Si_{3}N_{4}$-diaphragm, which functions as a thermal isolation layer, and the cold junctions on the dielectric membrane supported with the Si-substrate, which acts as a heat sink, and its ac-dc transfer characteristics were investigated with the fast reversed dc method. The respective thermal sensitivities of the converter with single bifilar heater were about 10.1 mV/mW and 14.8 mV/mW in the air and vacuum, and those of the converter with dual bifilar heater were about 5.1 mV/mW and 7.6 mV/mW, and about 5.3 mV/mW and 7.8 mV/mW in the air and vacuum for the inputs of inside and outside heaters, indicating that the thermal sensitivities in the vacuum, where there is rarely thermal loss caused by gas, are higher than those in the air. The ac-dc voltage and current transfer difference ranges of the converter with single bifilar heater were about ${\pm}1.80\;ppm$ and ${\pm}0.58\;ppm$, and those of the converter with dual bifilar heater were about ${\pm}0.63\;ppm$ and ${\pm}0.25\;ppm$, and about ${\pm}0.53\;ppm$ and ${\pm}0.27\;ppm$, respectively, for the inputs of inside and outside heaters, in the frequency range below 10 kHz and in the air.

• Applied Microscopy
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• v.33 no.2
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• pp.145-154
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• 2003

The present study was designed to demonstrate ionic zinc in the rat nasal mucosa by means of zinc selenium autometallography ($ZnSe^{AMG}$). Rats were given sodium selenide either intraperitoneally (i.p) or intranasally (i.n). Prior to the i.n. administration the rats were anesthetized with pentobarbital sodium (30 mg/kg, i.p.). A thin plastic tube coupled to a Hamilton syringe was then inserted into the right nostril and $10{\mu}l$ of the solution was instilled. For the i.p. administration non-anesthetized rats were given $100{\mu}l$ of the sodium selenide solution (10 mg/kg). Control rats were instilled with saline. After 2 hrs survival, the rats were anaesthetized and transcardially perfused with 3% glutaraldehyde. The olfactory area was removed and put into same fixative. The nose was then sectioned ($30{\mu}m$) horizontally, autometallography (AMG) was performed according to Danscher et al. (1997). After silver enhancement, fine AMG grains were scattered in the whole length of the olfactory epithelium containing olfactory receptor neurons, sustentacular and basal cells. However, much higher concentration of the AMG grains occupied near the surface and in the basal region of the olfactory epithelium. Both groups of i.p. and i.n. administration showed almost same level in the concentration of the AMG grains. In i.n. group, few AMG grains were also found in olfactory nerves of the lamina propria, suggesting zinc transport into the olfactory bulb via olfactory axons. At the electron microscopic level, the AMG grains were most entirely found in the supporting cells of the olfactory epithelium, and they were mostly localized in lysosome-like organelles. The i.n. group showed various signs of tissue damage of the olfactory mucosa, where dense concentration of AMG grains were localized at crystalloid structures. The present study demonstrated dense population of ionic zinc in the rat olfactory epithelium. zinc may play a role in the olfactory functioin and in the pathogenesis of the neurodegerative disorders affecting nose.

• The Journal of the Korean Society for Microbiology
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• v.21 no.4
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• pp.447-453
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• 1986

To diagnose the typhoid fever rapidly and accurately in clinically suspected patients, the levels of IgG subclass antibody were measured by enzyme-linked immunosorbent assay(ELISA). With symptom, blood culture and agglutination test, tested persons were categorized into 6 groups as typhoid fever, FUO, paratyphi A or B, other bacterial infctions, cancers, and control. ELISA was performed on the polyvinyl chloride plates coated with killed whole cell($10^8\;cell/ml$) of S. typhi 0901W by poly-L-lysine applied as binding substance (and polyvinyl chloride as solid phase). The distribution of the level of IgG subclass antibodies in each group was analyzed and compared with other groups. The results obtained were summarized as follow: 1. The optimal dilution of the sera from patients with typhoid fever was 1:160, and those of the sheep anti-human IgG subclass and the peroxidase conjugated rabbit anti-sheep IgG were 1:4000 and 1:5000, respectively. 2. The absorbance levels of IgG subclass in the sera of typhoid fever patients were as follows; a) IgG1 value is $0.439{\pm}0.110$ b) IgG2 value is $0.416{\pm}0.165$ c) IgG3 value is $0.449{\pm}0.145$ d) IgG4 value is $0.525{\pm}0.154$ IgG subclass levels in the sera of typhoid patients were much higher than in control group and patient with paratyphi A or B as well as other infectious diseases. The sensitivity and the specificity in differential diagnosis of typhoid fever and other febrile diseases were 92% and 79% in the assay of IgG1 respectively, whereas those in the assay of IgG2 were 97% and 72%, respectively (above absorbance 0.3). 3. The absorbance levels of IgG subclass in the serial sera of typhiod fever patients tend to decrease to the level of absorbance 0.3 in 10 months from the onset of illness. 4. The order of absorbance levels of IgG subclass in the serum of each group were typhoid fever, paratyphi A or B, other infectious diseases, control and cancer. 5. For the serodiagnosis of typhoid fever against other febrile diseases, the sensitivity and the specificity in the assay of IgG2 activity were 76% and 93% in absorbance 0.4, respectively. 6. In the distribution of the level of each IgG subclass in the sera of FUO patients which were suspected of typhoid fever, the positive rate was ranged from 36% to 82%. This suggest that more than 50% of FUO patients are caused by S. typhi.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.144-154
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• 2008

The purpose of this study was to describe quantitatively trophic structures and to analyze energy flows in the Lake Namyang using the Ecopath with ecosim (Walter et al., 1997). The sampling and analyses were carried out at 6 sampling sites of the Lake Namyang during May and November in 2007. A total of 10 groups were considered in this study (detritus, macrophytes, phytoplankton, zooplankton, zoobenthos, Cyprinus carpio, Carassius cuvieri, Carassius auratus, Pseudobagrus fulvidraco and other fishes) to assess the trophic relationship, energy flows and interactions between them. As a result, it was concluded that Lake Namyang was consisted of primary producers (Detritus, Macrophytes, Phytoplankton), primary consumers (Zooplankton, Zoobenthos, Cyprinus carpio, Carassius cuvieri, Carassius auratus, Other fishes) and secondary consumer (Pseudobagrus fulvidraco). The total system throughput was estimated at $14.1\;kg\;m^{-1}\;year^{-1}$ including a consumption of 39%, exports of 21%, respiratory flows of 12% and flows into detritus of 28%. MTI analyses indicate that Pseudobagrus fulvidraco have positive impact on Cyprinus carpio, Carassius cuvieri and Carassius auratus. On the other hand, other fishes have negative impact on Cyprinus carpio, Carassius cuvieri and Carassius auratus. All the functional groups except detritus had a negative impact on themselves and this may show within-group competition for the same resources.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.148-154
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• 2012

It was carried out to detect anti-impotence drug-like compounds, sibutramine and their analogues in dietary supplements, which are doubtful whether they include illegal compounds. A total of 51 food products were bought online and have been investigated. The separation was achieved on a C18 column, with the mobile phase made up of water (5 mM sodium hexanesulfonate and 0.1% phosphoric acid) and 95% acetonitrile, at a flow rate of 1.2 mL/min with gradient elution using by HPLC-DAD. The UV signals were monitored at 220 nm and 291 nm. LC-ESI-tandom MS was utilized to confirm that detected compounds in samples are the same as the reference materials. Two nutrient supplement foods and ginseng products were found to contain 1.3-82.1 mg of sildenafil, dimethylthiolsildenafil and pseudovardenafil per serving size. In addition, two other processed products were detected to contain 1.7 and 2.2 mg of didesmethylsibutramine, derived from sibutramine per serving size.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.3
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• pp.142-154
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• 2011

This study predicted the probability of corrosion initiation of reinforced concrete tunnel boxes structures using the Monte Carlo Simulation. For the inner wall and outer wall in the tunnel boxes, exposed to airborne chloride ion and seawater directly respectively, statistical values of parameters like diffusion coefficient D, surface chloride content $C_s$, cover depth c, and the chloride threshold level $C_{lim}$ were examined from experiment or literature review. Their average values accounted for $3.77{\times}10^{-12}m^2/s$, 3.0% by weight of cement, 94.7mm and 45.5mm for outer wall and inner wall, respectively, and 0.69% by weight of cement for D, $C_s$, c, and $C_{lim}$, respectively. With these parametric values, the distribution of chloride contents at rebar with time and the probability of corrosion initiation of the tunnel boxes, inner wall and outer wall, was examined by considering time dependency of chloride transport. From the examination, the histogram of chloride contents at rebar is closer to a gamma distribution, and the mean value increases with time, while the coefficient of variance decreases with time. It was found that the probability of corrosion initiation and the time to corrosion were dependent on the time dependency of chloride transport. Time independent model predicted time to corrosion initiation of inner wall and outer wall as 8 and 12 years, respectively, while 178 and 283 years of time to corrosion was calculated by time dependent model for inner wall and outer wall, respectively. For time independent model, the probability of corrosion at 100 years of exposure for inner wall and outer wall was ranged 59.5 and 95.5%, respectively, while time dependent model indicated 2.9 and 0.2% of the probability corrosion, respectively. Finally, impact of $C_{lim}$, including values specified in current codes, on the probability of corrosion initiation and corrosion free life is discussed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.149-154
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• 1992

Buckwheat has been a popular favorite food crop in Korea for a long time. The objective of the study was to investigate the effects of climatic conditions and cultural methods on grain yields of summer buckwheat variety Sinnong 1 planted during the spring season in Suwon, Korea from 1989 to 1991. Frost minimum temperature of late April was -0.3$^{\circ}C$ in 1990 being very low as compared with 3.7$^{\circ}C$ of the normal year, and affected early growth of the seedlings emerging from the soil surface. In late May of 1990, the frost minimum temperature was 7.3$^{\circ}C$ being low as compared with 8.8$^{\circ}C$ of the normal year, and also induced cold injury to fertilization and grain filling. Total precipitation 374.5mm of mid and late June, 1990 provided serious damage to the grain filling and maturing buckwheat seeds and along with causing seed sprouting before harvest. However, the climates of 1989 and 1991 were very good for the growth and development of spring-sown buckwheats. When summer buckwheat cultivar Sinnong 1 was planted on April 20, 1989, its highest grain yields 268-292kg /10a were harvested from the plots of seeding rate 8kg /10a, drill seeding and polyethylene film mulching, and the mean grain yield of the plots was 238kg /10a in 1989, but 64.3kg in Suwon, and 40.2kg /10a in Muan in 1990. In 1991 maximum grain yield 277kg /10a was produced from the April 15 planted and vinyl-mulched plot, and 255kg /10a from the April 25 planted and non-mulched plot. Herbicide Alachlor-sprayed plots produced lower grain yields than no weed control and manual weeding plots. Mechanized drill-seeding saved 83～84% in planting hours as compared with manual broadcasting 21.6 hours /ha, and produced 9% more in grain yields from the two-season croppings of mechanized drill-seeding culture being 364kg /10a in total yields per year.

• Journal of Animal Science and Technology
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• v.53 no.2
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• pp.147-154
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• 2011

This study was conducted to evaluate the effects of saponin contained plant extracts on in vitro rumen fermentation characteristics and methane production. Ruminal fluid was collected from rumen cannulated Hanwoo steers fed rice straw and concentrate (5:5). Collected rumen fluids, corn starch and buffer including saponin contained plant extracts (ginseng, Ogapi, soapwort, tea plant and yucca; 0.5%/15 ml) were incubated at $39^{\circ}C$ for 24 h. All incubations were repeated five times. Rumen pH in all treatments was lower (p<0.05) compared with that of the control (no addition) during incubation time. The concentration of total VFA in all treatments was higher (p<0.05) than that of the control after 12h incubation. Compared with the control, the concentration of acetate and propionate in all treatments was lower and higher after 6h incubation, respectively. The concentration of $NH_3$-N in all treatments was lower (p<0.05) than that of the control except for Ogapi or yucca extracts supplementation. The number of protozoa in all treatments was significantly (p<0.05) lower than that of the control except for soapwort extract supplementation. The total gas production and methane production in all treatments was higher (p<0.05) and lower (p<0.05) compared with the control, except for ogapi or soapwort extracts supplementation after 12h incubation, respectively. Therefore, reduction in methane production by saponins may could be results from decreased protozoal population without any negative in vitro fermentation.