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        검색결과 28

        1.
        2022.10 구독 인증기관·개인회원 무료
        This study presents a rapid and quantitative radiochemical separation method for Nb isotopes in radioactive waste samples from the nuclear power plant with anion exchange resin after Fe coprecipitation. After radionuclides were leached from the radioactive waste samples with concentrated HCl and HNO3, the Nb isotopes were coprecipitated with Fe after filtering the leaching solution with 0.45 micron HA filter, while the Sr, Tc and Ni isotopes were in the solution. The Nb isotopes were separated in HCl medium with anion exchange resin. The purified Nb isotopes were measured using a low level liquid scintillation counter after installing quenching curve with standard Nb-94 isotopes. The separation method for Nb isotopes investigated in this study was applied to neutron dosimeter samples from the nuclear power plant after validating the Nb activity concentration with gamma spectrometry system.
        2.
        2022.05 구독 인증기관·개인회원 무료
        This study presents a rapid and quantitative sequential separation method for H-3 and C-14 isotopes with distillation apparatus in environmental samples released from nuclear facilities. After adding 200 mg of granulated potassium permanganate and 500 mg of sodium hydroxide in 100 mL of sample solution, the sample solution was heated until approximately 10 mL of distillate, and the distillate fraction was removed. The sample solution was heated again until a minimum 10 mL of additional distillate was collected. 10 mL of distillate was transferred to the LSC vail and the measurement sample for H-3 was made by adding 10 mL of Ultima Gold LLT to the LSC vial. After adding 2.5 g of potassium persulfate, 2 mL of 1M silver nitrate and 15 mL of concentrated nitric acid to the remained sample solution, the sample solution was heated for 90 minutes and C-14 isotopes were adsorbed into 10 mL of Carbo-Sorb solution in glass vial. The measurement sample for C-14 was made by adding 10 mL of Permafluor to the C-14 fraction in glass vial. The purified H-3 and C-14 samples were measured by the liquid scintillation counter after quenching correction. The average recoveries of H-3 and C-14 with CRM were measured to be 96% and 85%, respectively. The sequential separation method for H-3 and C-14 investigated in this study was applied to activated charcoal filter produced from nuclear power plants after validating the reliability by result of proficiency test (KOLAS-KRISS, PT-2021-51).
        6.
        2023.05 KCI 등재 서비스 종료(열람 제한)
        In this study, 12 environmental factors were used to evaluate the potential habitat of Pteromys volans living around some development areas. The analyzed value ranged from 0 to 20.1, and the area with a score of 10 or less was analyzed to have a low possibility of inhabiting Pteromys volans. To verify the analyzed results, a field survey was conducted on areas with 10 or more scores, and traces of habitat of Pteromys volans were confirmed in areas with 16 or more scores. All the areas with an evaluation score of 16 or higher showed high crown density and age class. However, despite the high crown density and age class, the evaluation score in some areas was low owing to the influence of other environmental factors. Therefore, in evaluating Pteromys volans habitats, it is necessary to apply various and complex criteria suitable for field conditions rather than applying uniform and fragmentary environmental factors only.
        7.
        2023.04 KCI 등재 서비스 종료(열람 제한)
        Seventy Pipistrellus abramus samples were caught to analyze their sexual dimorphism and mophological characteristics. The mean HB and FA were 50.86 mm and 34.93 mm, respectively, based on external measurements and skull shape. The length of the TL, Hfcu, and Tra were approximately 70%, 55.6%, and 38% of the HB, Tib, and E, respectively. Both the lambdoid crest and the sagittal crest were well developed and the H.BC was approximately 84% of the W.BC. P2 was inside the toothrow and metacone of canine was clearly visible. According to the analysis of sexual dimorphism, the following characteristics were different in between males and females: WS, C-M3, C-C, M3-M3, LOM, LUC, and i-m3. The WS, C-M3, C-C, M3-M3, LOM, and i-m3 were bigger in females than males, whereas the LUC was bigger in males.
        8.
        2019.01 KCI 등재 서비스 종료(열람 제한)
        In order to collect base line data for setting up bat boxes, we established a total of 30 bat boxes in 2017. The bat boxes were established on the sidewalls of overpass and on the inside of girder bridges. Since establishing bat boxes, we regularly confirmed whether or not they were used; in June 2018, we confirmed that a total of six bat boxes were being used by Pipistrellus abramus and Myotis aurascens. It was confirmed that P. abramus used one bat box each out of five bat boxes, and that many adult females of M. aurascens used a single bat box as a place for maternity roosts. This result is the first use case for setting up bat boxes across the country, and could be used as baseline data to build roosts for bats by setting up additional bat boxes in the future.
        9.
        2018.08 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to identify the characteristics of the home range and habitat use of Rhinolophus ferrumequinum individuals that inhabit urban areas. The bats were tracked using GPS tags. For analysis of the home rage, Minimum Convex Polygon (MCP) and Kernel Home Range (KHR) methods were used. The landscape types of all positional information were analyzed using ArcGIS 9.3.1 (ESRI Inc.). The average home range of 16 R. ferrumequinum individuals was 68.63 ± 25.23 ha, and the size of the overall home range for the females (85.49 ± 25.40 ha) was larger than that for the males (51.76 ± 8.30 ha). The highest average home range for the males was found in August (61.21 ± 0.01 ha), whereas that for the females was found in September (112.27 ± 5.94 ha). The size of 50% KHR ranged from a minimum of 13.26 ha to a maximum of 31.00 for the males and a minimum of 8.02 ha to a maxinum of 42.16 ha for the females, showing no significant differences between the two sexes. In addition, males and females showed no differences in the size of 50% KHR in the monthly comparisons. However, the females showed differences in the size of their core area between periods before and after giving birth. The comparisons between 100% MCP and 50% KHR showed that the types of habitats used by R. ferrumequinum were mostly forest areas, including some farmlands. In addition, comparisons with a land cover map showed that the proportion of broad-leaved forests was the highest, followed by that of mixed forests.
        10.
        2017.07 KCI 등재 서비스 종료(열람 제한)
        We analyzed how foraging area use changed in female Pipistrellus abramus during the breeding season. Radio tracking was used to follow 12 female P. abramus in Gyeongju City, from 2013 to 2015. We followed three bats in each of four stages of reproduction: early pregnancy, late pregnancy, lactation, and post-lactation. Our data showed that the usable area of a foraging site and the area that was actually used by bats in that site were different, and foraging site use also differed according to stage of reproduction. The bats used arable land the most, with use rates of 57%, 40.4%, and 73.2% during early pregnancy, late pregnancy, and lactation, respectively. Bats in a post-lactation state did not use arable areas at all and instead foraged over bodies of water 90% of the time. There was no difference in the use of each foraging environment between bats in early pregnancy and late pregnancy. However, bats in late pregnancy and those that were lactating did use arable land to different extents, and bats that were lactating and those that were post-lactation also used arable land and bodies of water to different extents.
        11.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        In this study, we analyzed the changes in the echolocation and prey-capture behavior of the horseshoe bat Rhinolophus ferrumequinum from search phase to capture time. The experiment was conducted in an indoor free-flight room fitted with an ultra-high-speed camera. We found that the bats searched for food while hanging from a structure, and capturing was carried out using the flight membrane. In addition, it was confirmed that the mouth and uropatagium were continuously used in tandem during the capturing process. Furthermore, using Constant Frequency (CF), we confirmed that the prey catching method reflected the wing morphology and echolocation pattern of R. ferrumequinum. The echolocation analysis revealed that the pulse duration, pulse interval, peak frequency, start-FM-bandwidth, and CF duration decreased as the search phase approached the terminal phase. Detailed analysis of echolocation pulse showed that the end-FM bandwidth, which increases as it gets nearer to the capture time of prey, was closely related to the accurate grasp of the location of an insect. At the final moment of prey capture, the passive listening that stopped the divergence of the echolocation was identified; this was determined to be the process of minimizing the interruption from the echo of the echolocation call emitted from the bat itself and sound waves emitted from the prey.
        12.
        2017.04 KCI 등재 서비스 종료(열람 제한)
        Sightings of long-tailed bats have only been recorded twice in Korea, and their morphology and ecology are virtually unknown. We captured a female long-tailed bat in May 2016, in Gangwon Province, and to the best of our knowledge, this has been done for the first time in approximately 30 years. The captured bat had a very small craniofacial area and the length of its tibia was > 19 mm. The wing membrane penetrated the distal portion of the metatarsus of its first toe. The fur of the bat had a lusterless yellowish-brown color and its terminal tail vertebra was free beyond the posterior edge of the uropatagium. It had an obvious lambdoid crest on the lateral side. The anterior and central premolars were located inward with respect to the tooth row. In the mandible, the central premolar was located slightly inward and was nearly 80% of the anterior premolar in height.
        13.
        2014.03 KCI 등재 서비스 종료(열람 제한)
        The Ussurian tube-nosed bat (Murina ussuriensis) is a registered endangered species that has not been observed in South Korea since 1960. We were able to capture three individuals of M. ussuriensis between 2011 and 2013 at Sobaeksan National Park. The discovery of this species was the first time within 50 years. To collect basic data on the M. ussuriensis, we analyzed the external morphology and ultrasound characteristics of the captured bats. The results indicated that M. ussuriensis weigh approximately 5.2 g, which is less than that of a typical small bat such as Pipistrellus abramus. The bat's wing-type ratio was determined to be 1.22 and classified as a broad and short wingspan type. The bat uses FM signals for ultrasound with a peak frequency of 92 kHz. The M. ussuriensis seems to be a forest-dwelling bat that preys on insects by maneuvering expertly within the complex mazelike structure of forests. In the future, further research on the hibernation and foraging sites of the bats is necessary to protect and monitor the species.
        14.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        Between July and October 2011, radio-tracking was used to analyze the characteristics of home ranges and day roosts of Myotis aurascens by using 3 individuals (male: 2, female: 1). Bat capturing was conducted at a bridge and a nearby forest in Ulju-gun, Ulsan-si. We attached radio transmitters (0.32 g) to the bats and monitored them by using a radio receiver with a Yagi antenna. Home-range analysis of M. aurascens by using 100% minimum convex polygon (MCP) and 95% MCP showed an average of 106.5 ha and 89.3 ha, respectively, and 50% kernel home range (KHR) showed an average of 8.4 ha. Home range overlap of the 3 bats was observed at the bridge and at nearby water bodies as the core areas, and the size of the home range overlap was 7.3 ha by 100% MCP, 5.9 ha by 95% MCP, and 1.6 ha by 50% KHR. The home range for each bat consisted of the main foraging sites, and the types of foraging sites were similar. M. aurascens-01(M-01) used the bridge and nearby water bodies as the nightly main core areas, M. aurascens-02(M-02) used rice fields and water bodies adjacent to the forest as core areas, and M. aurascens-03(M-03) used water bodies and resident areas as core areas. Although rice fields and resident sites represented the core areas of the home ranges of M-02 and M-03, habitat use was the highest near water bodies as the core area for all the 3 bats. The types of day roosts in this study were a wooden house, canopies of a broad-leaved woodland, and banks of rice fields. The roosts in the wooden house and canopies of the broad-leaved woodland were located within the forest, and the roost in the banks of rice fields was also adjacent to the forest. Our results revealed that the main home range and foraging sites of M. aurascens were located near water bodies as the core area, and forests and places adjacent to the forests were used as day roosts.
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