• Journal of Korean Society of Forest Science
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• v.70 no.1
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• pp.55-62
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• 1985

This study was made on bamboo shoot's damage of Phyllostachys edulis by field mice in Jinju, Gyeongsangnam-do, and grasped the inhabitation environment by the analysis of around and lower vegetation in damaged bamboo stands, and made clear the species of field mice in damaged bamboo stand, the damaged degree and rate, therefore, were put in practice for contribution with damage prevention and extermination. The results were summarized as follows; The damaged degree were influenced by inhabitation environment and stand density around damaged bamboo stands. The damaged degree were shown 4,359.1 g with 7.1 shoots per. ha and the rate 0.23%. The damage season were from the middle of April to the middle and end of May, the most damaged season was about April 23. The length of damaged bamboo shoot was mean 28.12 cm, the inside diameter 7.49 cm, the weight 613.96 g. The damaged type of parts was shown to more numerous overland and surface damaged type of three types; overland, surface and underground damaged type. The field mice to be captured in damaged bamboo stand were three species; Apodemus agrarius coreae, Mus molossinus and Crocidura lasiura, the species of main damage was Apodemus agrarius coreae of captured Rodentia's 2 species. Crocidura lasiura in order Insectivora was found to inhabitate for the first time at southern region in Korea.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.51-57
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• 2008

This study demonstrates a variability in efficacy of mating disruption against the oriental fruit moth, Grapholita molesta, populations infesting apples cultivated in differential environmental conditions. Throughout the growing seasons, trap catches of G. molesta male moths and damaged leaf and fruit were examined to evaluate the efficacy of a commercialized mating disruptor. Treatment of the mating disruptor significantly reduced the trap catches of male moth in treated plot, compared to those of the untreated plot. This reduced trap catches were significantly correlated with leaf and fruit damage. Moreover, the highest host damage occurred in June just after the highest overwintering adult peaks in both plots. The treatment of mating disruptors in Chungsong effectively disrupted the overwintering population in April and May, resulting in no noticeable host damage during the following growing seasons. However, there was a marked difference in host damage between two plots, especially in late seasons. Variation in the efficacy of mating disruption technology in terms of host damage appeared to be related with nearby pheromone-untreated orchards, which may result in the immigration of gravid females.

• Economic and Environmental Geology
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• v.40 no.1 s.182
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• pp.129-140
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• 2007

CFC(CFC-12, CFC-11 and CFC-113) analytical system for air and water was constructed using a customized purge and trap extraction device and a gas chromatograph with an electron capture detector. Sampling methods of air and water for CFCs were also established. The analytical system was experimentally optimized to result in reproducibilities of triplicates less than 2% for current air samples and less than 5% for groundwater samples with CFC-12 concentration of 160 to 180 pg/kg, and verified with respect to the CFC system in USGS, which showed analytical results were in agreement within 10%. CFCs in air were monitored at three sites over 19-month period in the central part of South Korea, and the result indicates no significant local sources of CFCs in those areas. For groundwater in Jeju Island, CFCs were measured over a year with a two-month interval. The time-series data showed seasonal fluctuations which could be interpreted by the effect of recharge pulse derived from large amount of rainfall during monsoon period with a few month delay, which indicates high permeability of basaltic rocks in Jeju Island.

• Economic and Environmental Geology
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• v.53 no.3
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• pp.221-234
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• 2020

We occur together with telluride minerals. Fluid inclusions in the euhedral quartz crystals are mainly aqueous liquid-rich inclusions, which have salinities about 0.18-2.24 wt% NaCl equivalent. Some quartz vein contains aqueous vapor-rich inclusions as well. Homogenization temperatures of the assemblages of the liquid-rich inclusions are about 141-384 ℃, and the temperatures are lower at the shallower vein samples. In the high Au-Ag grade depth intervals, relatively deeper fluids have relatively higher salinities and homogenization temperatures, while shallower fluids show somewhat wider ranges. These might indicate that the deep Au-Ag bearing hydrothermal fluids at the Moisan area experienced phase separation as well as mixing with meteoric water by decreasing pressure. Au-Ag precipitation in the Moisan deposit is not associated with pyrite, but pyrite include Au-Ag bearing phase as an inclusion, which might possibly be tellurides or electrum. Au/Ag ratios in the Au-Ag bearing phase do not change with different depth.

• The Journal of the Petrological Society of Korea
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• v.27 no.4
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• pp.223-233
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• 2018

In this study, SHRIMP zircon U-Pb dating was performed on deformed granitic rocks in the Sancheong area in the northeastern part of the Jirisan area, southwest of Yeongnam Massif. Until now, these have been known as Precambrian or age-unknown old igneous rocks, but the U-Pb concordant ages obtained from two samples are $237.8{\pm}4.0Ma$ and $230.2{\pm}3.4Ma$, respectively, showing their emplacements in Early to Middle Triassic. These results indicate that the deformed granite was emplaced at about 238~230 Ma. The study area shows the characteristics of ductile deformation with prominent development of foliation, augen structure, and lineation. It is observed that the deformed granites occur as xenoliths within the syenite, indicating that the time of deformation is earlier than the intrusion of the syenite of about 220 Ma. The emplacement and deformation periods of the deformed granite is similar to that of Permo-Triassic granite gneisses distributed in the Gimcheon and Andong areas of the Yeongnam Massif. Taken together, the eastern part of the Yeongnam Massif, extending from the central part to the southwestern part, granite intrusions occurred at about 260-230 Ma, followed by metamorphism-deformation of about 230-220 Ma.

• Korean Journal of Environmental Biology
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• v.36 no.3
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• pp.412-423
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• 2018

In this study, we investigated the distribution and habitat of Tscherskia triton from 2014 to 2016 in Jeju Island. Nine individuals of T. triton were observed and captured from four habitat sites. Most of the habitats were of the natural and rural type, and urban type coexisted in some of the areas. The natural type of habitat comprised of forests, shrubs, and grasslands. The habitat of T. triton ranged vertically from 102 m in lowland to 742 m in a mountainous area and was not observed in altitude over 1,000 m. Small brooks, dry streams or wetlands were found to be located nearby the habitat of T. triton. The T. triton was distributed mainly in areas with natural vegetation and artificial plantation in company with the upper story vegetation on the ground of intact or incomplete layer structure, or the area with the relatively large distribution of shrubs and long grassland. The presence of roads and forest paths in these habitats suggested that the T. triton can thrive in areas with human disturbance. The designation of Halla Mountain National Park in Jeju Island as a conservation area prevents damage or loss of the habitat due to any artificial development. However, frequent human disturbances occurring in grassland is tolerated by small mammals. Therefore, in order to help T. triton maintain a stable population density, it is essential that various types of the habitat should be conserved in the middle mountain areas and the grasslands in lowlands should be well protected.

• Korean Journal of Environmental Biology
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• v.41 no.2
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• pp.101-108
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• 2023

Recently, in relation to climate change, many studies have been conducted to predict the potential habitat area and distribution range of tilapia and the suitability of habitat for each species. Most tilapia are tropical fish that cannot survive at water temperatures below 10 to 12℃, although some tilapia can survive at 6 to 8℃. This study predicted habitable areas and the possibility of spreading of habitat ranges of tilapia (Oreochromis niloticus and Oreochromis aureus) known to inhabit domestic streams. Due to climate change, it was found that habitats in the Geum River, Mangyeong River, Dongjin River, Seomjin River, Taehwa River, Hyeongsan River, and the flowing in East Sea were possible by 2050. In addition, it was confirmed that tilapia could inhabit the preferred lentic ecosystem such as Tamjin Lake, Naju Lake, Juam Lake, Sangsa Lake, Jinyang Lake, Junam Reservoir, and Hoedong Reservoir. In particular, in the case of tilapia, which lives in tributaries of the Geumho River, Dalseo Stream, and the Nakdong River, its range of habitat is expected to expand to the middle and lower of the Nakdong River system. Therefore, it is judged that it is necessary to prepare physical and institutional management measures to prevent the spread of the local population where tilapia currently inhabits and to prevent introduction to new habitats.

• Clean Technology
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• v.15 no.1
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• pp.9-15
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• 2009

Catalytic hydrodechlorination of PCBs (polychlorinated biphenyls) included in the transformer oil was carried out to detoxify PCBs and to recycle the treated oil. Catalysts such as 0.98 wt% Pt and 0.79 wt% Pd on ${\gamma}$-alumina (${\gamma}-Al_2O_3$) support, 12.8 wt% Ni on ${\gamma}-Al_2O_3$, and 57.6 wt% Ni on silica-alumina ($SiO_2-Al_2O_3$) support were used for the catalytic hydrodechlorination. Various supercritical fluids such as carbon dioxide, propane and isobutane were used as reaction media. The effects of reaction temperature, reaction time, catalysts, and supercritical fluids on the catalytic hydrodechlorination were examined in detail. The detoxification degree increased in the order of Ni > Pd > Pt. This is possibly due to higher metal loading and larger metal size of the Ni catalyst. Below $175^{\circ}C,\;scCO_2$ was found as the most effective reaction media for the catalytic hydrodechlorination of PCBs included in the transformer oil.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1B
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• pp.89-100
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• 2010

The performance evaluation of a conventional Wave Resonator at the entrance of harbors against solitary wave has been performed using 3D numerical wave flume. A wave resonator has been designed for the attenuation of the transmitted wave energy by trapping the short periodic incident waves only. In this study, however, the controlled performance of the wave resonator by its various widths has been numerically investigated for solitary waves. Source distribution method based on the Green function and the 3D one-field Model for immiscible TWO-Phase flows (TWOPM-3D) using 3D numerical wave flume were used for the short-periodic waves and the solitary waves, respectively, and these models were verified through the comparisons with the previous experimental and numerical results by other researchers. It was confirmed that the wave resonator is effective enough to control the solitary waves as well as the periodic waves when it compares with the case of no resonance system. Further, it was found that there is the optimal width of a wave resonator to attenuate the target solitary waves.

• Journal of the Mineralogical Society of Korea
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• v.20 no.1 s.51
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• pp.47-60
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• 2007

While sedimentological researches on Western coastal tidal flats of Korea have been much pelformed previously, mineralogical and biogeochemical studies are beginning to be studied. The objectives of this study were to investigate mineralogical characteritics of the inter-tidal flat sediments and to explore phase transformation of iron(oxyhydr)oxides and biomineralization by metal-reducing bacteria enriched from the inter-tidal flat sediments from Muan, Jeollanam-do, Korea. Inter-tidal flat sediment samples were collected in Chungkye-myun and Haeje-myun, Muan-gun, Jeollanam-do. Particle size analyses were performed using the pipette method and sedimentation method. The separates including sand, silt and clay fractions were examined by scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), and X-ray diffiaction (XRD). After enriching the metal-.educing bacteria from the into,-tidal flat sediments, the bacteria were used to study phase transformation of the synthesized iron (oxyhydr)oxides and iron biomineralization using lactate or glucose as the electron donors and Fe(III)-containing iron oxides as the electron accepters. Mineralogical studies showed that the sediments of tidal flats in Chung]rye-myun and Haeje-myun consist of quartz, plagioclase, microcline, biotite, kaolinite and illite. Biogeochemical researches showed that the metal-reducing bacteria enriched from the inter-tidal flat sediments reduced reddish brown akaganeite and mineralized nanometer-sized black magnetite. The bacteria also reduced the reddish brown ferrihydrite into black amorphous phases and reduced the yellowish goethite into greenish with formation of nm-sized phases. These results indicate that microbial Fe(III) reduction may play one of important roles in iron and carbon biogeochemistry as well as iron biomineralization in subsurface environments.