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        검색결과 32

        2.
        2025.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Photometric and spectroscopic observations of GV Leo were performed from 2017 to 2024. The light curves show a flat bottom at the primary eclipse and the conventional O’Connell effect. The echelle spectra reveal that the effective temperature and rotation velocity of the more massive secondary are Teff,2 = 5220 ± 120 K and v2 sin i = 223 ± 40 kms−1, respectively. Our binary modeling indicates that the program target is a W-subclass contact binary with a mass ratio of q = 5.48, an inclination angle of i = 81.◦68, a temperature difference of (Teff,1 − Teff,2) = 154 K, and a filling factor of f = 36%. The light asymmetries were reasonably modeled by a dark starspot on the secondary’s photosphere. Including our 26 minimum epochs, 84 times of minimum light were used to investigate the orbital period of the system. We found that the eclipse times of GV Leo have varied by a sinusoid with a period of 14.9 years and a semi-amplitude of 0.0076 days superimposed on a downward parabola. The periodic modulation is interpreted as a light time effect produced by an unseen outer tertiary with a minimum mass of 0.26 M⊙, while the parabolic component is thought to be a combination of mass transfer (secondary to primary) and angular momentum loss driven by magnetic braking. The circumbinary tertiary would have caused the eclipsing pair of GV Leo to evolve into its current short-period contact state by removing angular momentum from the primordial widish binary.
        4,300원
        7.
        2020.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        ZnO thin films are of considerable interest because they can be customized by various coating technologies to have high electrical conductivity and high visible light transmittance. Therefore, ZnO thin films can be applied to various optoelectronic device applications such as transparent conducting thin films, solar cells and displays. In this study, ZnO rod and thin films are fabricated using aqueous chemical bath deposition (CBD), which is a low-cost method at low temperatures, and environmentally friendly. To investigate the structural, electrical and optical properties of ZnO for the presence of citrate ion, which can significantly affect crystal form of ZnO, various amounts of the citrate ion are added to the aqueous CBD ZnO reaction bath. As a result, ZnO crystals show a nanorod form without citrate, but a continuous thin film when citrate is above a certain concentration. In addition, as the citrate concentration increases, the electrical conductivity of the ZnO thin films increases, and is almost unchanged above a certain citrate concentration. Cu(In,Ga)Se2 (CIGS) solar cell substrates are used to evaluate whether aqueous CBD ZnO thin films can be applicable to real devices. The performance of aqueous CBD ZnO thin films shows performance similar to that of a sputter-deposited ZnO:Al thin film as top transparent electrodes of CIGS solar cells.
        4,000원
        8.
        2019.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Plant growth and morphology are affected by light environments. The morphogenesis and growth of the plants growing in plant factories are different from those grown under sunlight due to the effect of far-red light included in sunlight. The objective of this study was to compare the morphogenesis and growth of cucumber plants grown under artificial sunlight, high pressure sodium lamp (HPS), and HPS with additional far-red light (HPS+FR). The artificial solar (AS) with a spectrum similar to sunlight was manufactured using sulfur plasma lamp, incandescent lamp, and green-reducing optical film. HPS was used as a conventional electrical light source and far-red LEDs were added for HPS+FR. The optical properties of each light source was analyzed. The morphogenesis, growth, and photosynthetic rate were compared in each light source. The ratio of red to far-red lights and phytochrome photostationary state were similar in AS and HPS+FR. There were significant differences in morphology and growth between HPS and HPS+FR, but there were no significant differences between AS and HPS+FR. SPAD was highest in HPS, while photosynthetic rate was higher at AS and HPS. Although the photosynthetic rate in HPS+FR was lower than HPS, the growth was similar in AS. It was because canopy light interception was increased by longer petioles and larger leaf areas induced by FR. It is confirmed that the electrical light with additional far-red light induces similar photomorphogenesis and growth in sunlight spectrum. From the results, we expect that similar results will be obtained by adding far-red light to electrical light sources in plant factories.
        4,000원
        9.
        2018.10 구독 인증기관·개인회원 무료
        전라북도 완주군 구이면에서 채집한 사마귀목(Mantodea) 사마귀과(Mantidae) 넓적배사마귀속(Hierodula)의 한국 미기록종 Hierodula formosana Giglio-Tos, 1912, 붉은긴가슴넓적배사마귀(신칭)을 처음 보고한다. 이 종은 그동안 국내에 알려진 Hierodula patellifera (Serville, 1839), 넓적배사마귀와 동일하게 느티나무, 벚나무 등 활엽수의 우거진 수관부에 매달려 전 생애를 보내는 생태적 특징이 있다. 형태적으로 같은 속 넓적배사마귀와 비교하였을 때, 수컷생식기의 차이가 뚜렷하고 앞다리 기절부에 9~11개의 돌기가 있다. 또한 전흉이 뚜렷이 길고 앞가슴 아랫면이 붉은 빛을 띠는 등 구별이 가능한데, 현재 일본에서 확산되고 있는 외래종 Hierodula sp.와 동일종으로 여겨진다. 2017년 9월 전주에서 처음 암컷 3개체가 비공식적으로 채집된 이후, 2018년 9월 완주군 구이면 일대를 조사하였을 때, 총 암컷 4개체, 수컷 10개체를 채집할 수 있었다. 또한 유충의 탈피각, 전년도 알집 등이 함께 확인됨으로써 국내에 최근 정착한 외래종으로 의심되어 이를 보고하고자 한다.
        10.
        2017.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        배경/목적: 담도암에서 플라스틱 스텐트 너비에 따른 스텐트 생존 차이에 대한 데이터는 부족하다. 이번 연구의 목적은 담도암에서 7-프렌치와 10-프렌치 플라스틱 스텐트의 생존 차이를 보고 어떤 인자가 개방성에 영향을 미치는지 확인하고자 한다. 방법: 2010년 1월부터 2014년 10월까지 연세대학교 원주세 브란스기독병원에서 담도암으로 담도가 막힌 환자들을 등록 하였다. 결과: 총 215명(7-프렌치:10-프렌치 = 89명:126명)의 환자 를 후향적으로 등록하였다. 암의 위치는 총담관(111명), 간문 부 담관(45명), 바터팽대부(59명)였다. 스텐트 이동이나 폐쇄는 두 군 간에 통계적 차이가 없었다. 중앙 스텐트 생존은 7-프렌치의 경우 3.3개월이었고 10-프렌치의 경우 5.9개월이었다 (p = 0.543). 플라스틱 스텐트 너비는 스텐트 생존에 영향을 미치지 않았다(Hazard Ratio: 1.11, 95% CI 0.71-1.73, p = 0.649). 결론: 담도암 치료에 있어 7-프렌치와 10-프렌치 플라스틱 스텐트는 스텐트 이동이나 폐쇄 차이가 없었고 스텐트 생존에 있어 7-프렌치 플라스틱 스텐트가 10-프렌치에 비해 열등하지 않았다
        4,000원
        11.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the antidiabetic effect of amaranth grain ethanol extract (AEE) in a diabetic animal model, db/db mouse. The mice were divided into 4 groups: normal control mice (C57BL/6J), diabetic mice (C57BL/6J db/db), diabetic mice fed a lower concentration of AEE (0.3 mg/kg), and diabetic mice fed a higher concentration of AEE (0.5 mg/kg). After 10 weeks of treatment, body weights, blood insulin levels and blood glucose levels of each group were compared. At the end of treatment, the results showed that both AEE supplemented groups had lower body weights than those in the diabetic groups although higher than those in the normal groups. Moreover, in both AEE supplemented groups, serum insulin levels were higher and blood glucose levels were lower than those in the diabetic groups although both values were higher than those in the normal groups. The results of this study suggest that AEE can alleviate many of the common symptoms of diabetes in diabetic mice and, therefore, has potential as a therapeutic supplement for normalization of blood glucose and insulin levels in humans.
        4,000원
        12.
        2016.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        간의 염증성 가성종양(inflammatory pseudotumor)은 조 직학적으로 형질세포의 침윤 및 반응성 섬유성 염증을 특징으로 하는 양성 질환이다. 이는 악성 종양과의 감별이 쉽지 않다. 저자들은 간내 담도암으로 오인된 염증성 가성종양 1 예를 보고하는 바이다. 74세 남자가 1-2주 전부터의 근육통과 황달이 있어 입원하였다. 진행한 복부초음파, 복부 전산 화단층촬영, 자기공명영상에서 간내 담도암으로 생각되었으나 간 조직검사에서 염증성 가성종양으로 진단되었다. 항생제 사용 및 보존적인 치료 후 증상이 호전되어 퇴원하였고 이후 추적 복부 전산화단층촬영에서 병변은 사라졌다.
        4,000원
        13.
        2015.10 구독 인증기관·개인회원 무료
        This study was carried out to investigate insect community structure from different habitats. We performed day and night collection at three different habitats (mountain, coast and rural area) of island Deokjeok, island Soya and island Mungap from May to September in 2014. A total of 3,482 individuals of 725 species, 119 families belonging to 10 orders were collected and identified. A dominant species was Corymbia rubra (Cerambycidae) despite a very low percentage of the species among the catches. Results of ANOVA test showed a significant effect of habitats typeon species diversity. Also, combination of seasons and habitats types were significantly influential with species abundance and species diversity. Indicator species analysis (ISA) result identified 121 significant (p < 0.05) indicator species; one species for the habitats cluster, 93 species for the season cluster and 27species for combination of habitats with seasons.
        14.
        2015.04 구독 인증기관·개인회원 무료
        An insect faunal survey was carried out to investigate insect community structure along the vegetation community to monitor insect species in forest ecosystem. We performed day and night collections from June to August along three vegetation communities of Is. Nam-hae in 2014: the first stand with Pinus thunbergii, the second P. thunbergii with Quercus serrata and the third P. thunbergii with various Quercus species. In total 2,259 individuals of 532 species, 99 families, 13 orders are identified. Cluster Analyses (CA) showed that all three vegetation communities were relatively similar between vegetation community types. According to indicator species analysis (ISA) result, nine significant indicator species were identified (p < 0.05); five species were found to be affected by the vegetation cluster and four species the month cluster.
        15.
        2015.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        본 증례는 복강경 담낭절제술 후 10년이 경과되어 발생한 총담관 결석의 예로, 결석 내 포함된 외과용 클립이 담관결석의 원인이 되었을 것으로 추정된다. 내시경으로 제거한 총 담관결석 내에 외과용 클립이 발견되어 수술시 사용한 외과용 클립이 총담관 내로 이동하여 총담관 내 결석의 핵으로 작용했을 가능성을 뒷받침한다. 담낭 절제술 후 발생한 우상 복부 통증으로 내원한 환자에서 외과용 클립에 의한 총담관 결석은 진단에 있어 고려해야 할 부분으로 생각된다. 진단은 단순복부촬영에서 우상복부에 금속성 물질이 관찰된다면 의심할 수 있겠으나, 내시경적 담췌관조영술에서 총담관 내에 음영결손과 결석 내부에 금속성 물질이 관찰될 때 가능하다. 치료는 일반적인 총담관 결석의 치료와 동일하며, 내시경을 이용한 유두괄약근 절개술 후 바스켓 및 풍선 카테터를 이용한 결석 제거가 유용하다.
        3,000원
        18.
        2023.11 서비스 종료(열람 제한)
        When the parent radionuclide decays, the progeny radionuclide is produced. Accordingly, the dose contribution of the progeny radionuclide should be considered when assessing dose. For this purpose, European Commission (EC) and International Atomic Energy Agency (IAEA) provide weighting factors for dose coefficient. However, these weighting factors have a limitation that does not reflect the latest nuclide data. Therefore, in this study, we analyzed the EC and IAEA methodology for derivation of weighting factor and used the latest nuclide data from ICRP 107 to derive weighting factors for dose coefficient. Weighting factor calculation is carried out through 1) selection of nuclide, 2) setting of evaluation period, and 3) derivation based on ICRP 107 radionuclide data. Firstly, in order to derive the weighting factor, we need to select the radionuclides whose dose contribution should be considered. If the half-life of progeny radionuclides sufficiently short compared to the parent radionuclide to achieve radioactive equilibrium, or if the dose coefficient is greater of similar to that of the parent radionuclide and cannot be ignored, the dose contribution of the progeny radionuclide should be considered. In order not to underestimate the dose contribution of progeny radionuclides, the weighting factors for the progeny nuclides are taken as the maximum activity ratio that the respective progeny radionuclides will reach during a time span of 100 years. Finally, the weighting factor can be derived by considering the radioactivity ratio and branch fraction. In order to calculate the weighting factor, decay data such as the half-life of the radionuclide, decay chain, and branch fraction are required. In this study, radionuclide data from ICRP 107 was used. As a result of the evaluation, for most radionuclides, the weighting factors were derived similarly to the existing EC and IAEA weighting factors. However, for some nuclides, the weighting factors were significantly different from EC and IAEA. This is judged to be a difference in the half-life and branch fraction of the radionuclide. For example, in the case of 95Zr, the weighting factor for 95mNb showed a 35.8% difference between this study and previous study. For ICRP 38, when 95Zr decays, the branch fraction for 95mNb is 6.98×10-3. In contrast, for ICRP 107, the branch fraction is 1.08×10-2, a difference of 54.7%. Therefore, the weighting factor for the dose coefficient based on ICRP 107 data may differ from existing studies depending on the half-life and decay information of the nuclide. This suggests the need for a weighting factor based on the latest nuclide data. The results of this study can be used as a basis for the consideration of dose contributions for progeny radionuclides in various dose assessments.
        19.
        2023.11 서비스 종료(열람 제한)
        In Korea, most temporary storage facilities for spent nuclear fuel are nearing saturation. As an alternative to this, the 2nd basic plan for high-level radioactive waste management specified the operation plan of dry interim storage facility. Meanwhile, the NSSC No. 2021-19 stipulates that it is necessary to evaluate the possibility and potential effect of accident before operating interim storage facility. Therefore, this study analyzed the categories of accident scenarios that may occur in dry storage facility as part of prior research on this. We investigated the case of categorization of dry storage facility accident scenarios of IAEA, NRC, KAREI, and KINS. The IAEA presented accident scenarios that could occur in on-site dry storage facility operated with silo and cask method. NRC has classified accident scenarios in dry storage facility and estimated the probability of accidents for each. KAERI and KINS selected major accident scenarios and analyzed the processes for each, in preparation for the introduction of dry storage facility in Korea in the future. Overall, a total of 10 accident scenarios were considered, and the scenarios considered by each institution were different. Among 10 scenarios, cask drop and aircraft collision were included in the categorization of most institutions. The results of this study can be used as basic data for cataloging accidents subject to safety evaluation when introducing dry interim storage facility in Korea in the future.
        20.
        2023.05 서비스 종료(열람 제한)
        As nuclear power plants are operated in Korea, low and intermediate-level radioactive wastes and spent nuclear fuels are continuously generated. Due to the increase in the amount of radioactive waste generated, the demand for transportation of radioactive wastes in Korea is increasing. This can have radiological effect for public and worker, risk assessment for radioactive waste transportation should be preceded. Especially, if the radionuclides release in the ocean because of ship sinking accident, it can cause internal exposure by ingestion of aquatic foods. Thus, it is necessary to analyze process of internal exposure due to ingestion. The object of this study is to analyze internal exposure by ingestion of aquatic foods. In this study, we analyzed the process and the evaluation methodology of internal exposure caused by aquatic foods ingestion in MARINRAD, a risk assessment code for marine transport sinking accidents developed by the Sandia National Laboratory (SNL). To calculate the ingestion internal exposure dose, the ingestion concentrations of radionuclides caused by the food chain are calculated first. For this purpose, MARINRAD divide the food chain into three stages; prey, primary predator, and secondary predator. Marine species in each food chain are not specific but general to accommodate a wide variety of global consumer groups. The ingestion concentrations of radionuclides are expressed as an ingestion concentration factors. In the case of prey, the ingestion concentration factors apply the value derived from biological experiments. The predator's ingestion concentration factors are calculated by considering factors such as fraction of nuclide absorbed in gut, ingestion rate, etc. When calculating the ingestion internal exposure dose, the previously calculated ingestion concentration factor, consumption of aquatic food, and dose conversion factor for ingestion are considered. MARINRAD assume that humans consume all marine species presented in the food chain. Marine species consumption is assumed approximate and conservative values for generality. In the internal exposure evaluation by aquatic foods ingestion in this study, the ingestion concetration factor considering the food chain, the fraction of nuclide absorbed in predator’s gut, ingestion rate of predator, etc. were considered as influencing factors. In order to evaluate the risk of maritime transportation reflecting domestic characteristics, factors such as domestic food chains and ingestion rate should be considered. The result of this study can be used as basis for risk assessment for maritime transportation in Korea.
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