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        검색결과 220

        21.
        2022.06 구독 인증기관 무료, 개인회원 유료
        We assume that, even though Jeju Island ‘Peace’ Cherry Trees (1913), happened at different time and places, it connects each other as (1919) and Busan UN Forces Cemetery (1951) as an important connected diplomatic event of Provisional Government and Republic of Korea positively. Especially, it will bring a significant positive impact to Asia Community if we organize 2023 Korean Week Event: The First Korea Congress (1919) and Busan UN Forces Cemetery (1951) and suggest the invitation issues of UN Asia Headquarters to the Republic of Korea (2023) into Busan metropolitan city(Seoul, Kyunggi, Jeju Special Self-Governing Province) of Republic of Korea. We also assume Korean’s tolerance philosophy will Koreans to unite each other together if they will succeed to share spirit of tolerance from Busan UN Forces Cemetery. We have 2314 graves from 11 countries at the graveyard for UN Forces in Busan, which was built as the UN Headquarters Cemetery in January of 1951 and used as memorial space for participation in the Korean War, who had involved the War beyond their sacrifices. Recently we had 13 veterans, who got buried coming from 4 Americans, thre Hollanders, 2 Frenchmen, 2 Germans, 2 Englishmen, 1 Canadian and 1 headband after they died in their countries. (Joongang daily newspaper June 19, 2022). In the end they become Asian spirit of Toleran명 at the Busan UN Forces Cemetery beyond borders.
        3,000원
        22.
        2022.05 구독 인증기관·개인회원 무료
        Complexation of actinides and lanthanides with carboxylic organic ligands is known to facilitate migration of radionuclides from deep geological disposal systems of spent nuclear fuel. In order to examine the ligand-dependent structures of trivalent actinides and lanthanides, a series of Eu(III)-aliphatic dicarboxylate compounds, Eu2(oxalate)3(H2O)6, Eu2(malonate)3(H2O)6, and Eu2(succinate)3(H2O)2, were synthesized and characterized by using X-ray crystallography and time-resolved laser fluorescence spectroscopy. Powder X-ray diffraction results captured the transition of the coordination modes of aliphatic dicarboxylate ligands from side-on to end-on binding as the carbon chain length increases. This transition is illustrated in malonate bindings involving a combination of side-on and end-on modes. Strongly enhanced luminescence of these solid compounds, especially on the hypersensitive peak, indicates a low site symmetry of these solid compounds. Luminescence lifetimes of the compounds were measured to be increased, which is ascribed to the displacement of water molecules in the innersphere of Eu center upon bindings of the organic ligands. The numbers of remaining bound water molecules estimated from the increased luminescence lifetimes were in good agreement with crystal structures. The excitation-emission matrix spectra of these crystalline polymers suggest that oxalate ligands promote the sensitized luminescence of Eu(III), especially in the UV region. In the case of malonate and succinate ligands, charge transfer occurs in the opposite direction from Eu(III) to the ligands under UV excitation, resulting in weaker luminescence.
        23.
        2022.05 구독 인증기관·개인회원 무료
        There are three questions arise in radioactivity measurements: (1) Dose the measured value originate from the radioactivity being present in the sample? (2) Is the measurement procedure suitable for the intended measurement purpose with respect to the requirements? (3) What is a range of values fairly sure our true value lies in with a specified probability? These three questions are answered by determining characteristic limits (decision threshold, detection limit and limits of the coverage interval), which are widely used as part of quality assurance in radioactivity measurements. In the past, numerous papers have focused on the questions in different ways, and have drawn a variety of conclusions about the meaning of the different characteristic limits using various terms and symbols. In recent years, substantial efforts were made in order to obtain a systematic and unified way to calculate and express these limits. As a result, the ISO 11929 Series which specify a procedure for calculation of the characteristic limits have been developed. This paper is focused on the calculations of characteristic limits for noble gas monitor (NGM204 monitor) that offers the continuous measurements of radioactive noble gases discharged from the stacks of the HANARO reactor facility. The calculations are based on the standard ISO 11929 as well as the traditional formulas provided by NUREG 1576, ANSI N42-18, ANSI N42-17 and DIN 25482. A comparison is made among the results obtained from the formulas given in each literature.
        24.
        2022.05 구독 인증기관·개인회원 무료
        Safety evaluation of high-level radioactive waste disposal facilities including spent nuclear fuel is a very urgent and critical issue, and in order to do so, it is very important to develop a safety case that includes Feature, Event, Process (FEP) analysis, scenario development, and scenario uncertainty evaluation. In the case of Korea, the disposal of spent nuclear fuel is recognized as an unavoidable option, and in the end, Korea’s specific FEP (SFEP) development and safety evaluation according to the scenario should be conducted. Because each country’s situation and environment are different, it is necessary to develop an SFEP based on a generic FEP (International FEP). To this end, an understanding of IFEP is essential. In this study, about 1,000 major terms appearing in the OECD/NEA IFEP are classified to where each of them belongs among F, E, and P, and which FEP each word belongs to, and the correlation between the frequency of occurrence and each term is analyzed. This result will serve as a reference for the results of SFEP analysis such as POSIVA and SKB, which our research team will analyze later. In addition, each term belongs to which academic field, and the most appropriate translation for translating each term into Korean is also described.
        25.
        2022.05 구독 인증기관·개인회원 무료
        FTIR (Fourier Transform Infrared) and Raman spectra of KJ-II bentonite provided by Clariant Korea were compared with those of MX-80 bentonite. The FTIR spectra were obtained using a Nicolet 5 FTIR spectrometer (Fisher Scientific) equipped with a diamond ATR (Attenuated Total Reflection) module. The spectra were collected for 64 scans with a resolution of 4 cm−1. Raman spectra were obtained using an optical microscope (Olympus, BX43) and a spectrometer (Andor, SR- 500). The laser beam was focused using an objective lens with a magnifying power of 50. The backscattered light from the sample was collected into an optical fiber with a core diameter of 0.4 mm. The Raman signals were recorded with CCDs (Andor, DV401A-BV for 532 nm laser wavelength and DV420A-OE for 638 and 785 nm laser wavelengths). Each pixel of CCD received the signal for 1 s and its 1000 times accumulated data were collected. The FTIR spectra of the two bentonite samples are very similar. The FTIR spectra of both bentonites showed absorption bands at 3623, 3399, 3231 cm−1 in the higher wavenumber region and at 1637, 1443, 1117, 997, 914, 887, 847, 797, 611, 515, 414 cm−1 in the lower wavenumber region. A sharp band at 3623 cm−1 and the strong band at 997 cm−1 correspond to the OH stretching of structural hydroxyl groups and the Si-O stretching vibration, respectively. In addition to these clear bands, several absorption bands observed in this experiment are well matched with the results reported in various literatures. Unlike the FTIR spectrum, it is not easy to observe the Raman bands of bentonite. The reason is that strong fluorescence interferes with the Raman spectrum. The two bentonite samples showed different fluorescence intensities. In the case of MX-80 bentonite, no clear Raman band was observed due to the influence of very strong fluorescence. KJ-II bentonite showed a relatively weak fluorescence intensity and Raman bands were partially visible at around 147, 260, 397, 709, and 1279 cm−1. In particular, the band at 1279 cm−1 is wide and sturdy. It was observed that the non-powder samples showed a better quality spectra. The Raman characteristics of KJ-II bentonite, which depend on the incident laser wavelength and the sample pretreatment, are discussed in detail.
        28.
        2022.03 구독 인증기관 무료, 개인회원 유료
        This study aims to restore the dignity of the elderly based on “filial piety” and community values in preparation for the 'silver tsunami' in Jeju by studying the case of Whitney Center in the United States, PASSi, Jeju's Isidol Nursing Home, and the haenyeo society. The main goal was to develop the Asian Jeong Nang model which was named by professor Koh Chang Hoon, Chair of Island Research Institute at Jeju National university. Jeong Nang(정낭) is the gateway with 3 wooden bars to the traditional residential space of Jeju where several generations live together. Dr. Hesung Chun Koh, Chair of East Rock Institute gave me motivation and support for the study of the elderly welfare model at the Jeju National University Island Research Institute. As the head of this study, I was dispatched from the Jeju National University Island Research Institute to the East Rock Institute (ERI). Dr. Hesung Chun Koh, M.D. Ann Datunashivili who is a practice professor at Medical School of Yale and in charge of Medical Center of Whitney Center. and Mike RambaRose who is Chief Executive Officer of Whitney Center, supported my research. In addition ImJa Choi, CEO of PASSi, also allowed two research students, Lee Seung Yong and Ko Yu Seok, from Jeju National University, to help my research related to psycho-social approach for the elderly at PASSi. This study was intended to develop a model for senior citizens in Korea through Hesung Chun Koh's ERI CCAI Model, Whitney Center's residential apartment model for retired seniors, and PASSi's community care model for the multi-cultural community.
        5,100원
        29.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study examined the effects of hot deboning and the irradiation of raw pork on the physicochemical properties of pork sausages. Pigs were deboned with a carcass (loin surfaces) temperature of 5℃ (cold) or 15℃ (hot). Each deboned raw pork loins were then irradiated at 0 kGy or 4 kGy. Emulsion-type sausages were prepared from each treated meat with other ingredients including fat, ice, salt, phosphate, and seasoning powder. Then sausage products were analyzed for their physiochemical properties and microbial spoilage up to 10 days. Emulsion stability of sausage products with hot deboning was better than the cold carcass up to three days. Sausage products with irradiated hot carcasses showed less cooking loss than from non-irradiated carcasses on day 10. Hardness, gumminess, and chewiness of the sausages decreased significantly with increasing storage time for all sausage products (p<0.05), but the sausage products with irradiated hot carcasses showed a smaller reduction compared with non-irradiated. Lipid oxidation was not significantly different in the sausage products with hot or cold deboning (p>0.05), but the sausage products from non-irradiated meats showed changes from 0.43 to 1.59 (MDA mg/kg of meat) in 10 days (p<0.5). Total plate count and E. coli count were significantly lower in the sausage products from irradiated meat (p<0.05). Finally, irradiating hot deboned meat at 4 kGy can be an excellent alternative for producing raw meat for sausages with promising microbiological and physicochemical properties.
        4,000원
        30.
        2021.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The Mn-Zn ferrite powders were prepared by high energy ball milling, then compacted and sintered at various temperatures to assess their sintering behavior and magnetic properties. The initial ferrite powders were spherical in shape with the size of approximately 70 m. After 3 h of ball milling at 300 rpm, aggregated powders ~230 nm in size and composed of ~15 nm nanoparticles were formed. The milled powders had a density of ~70 % when compacted at 490 MPa for 3 min. In the samples subsequently sintered at 1,273 K ~ 1,673 K for 3 h, the MnZnFe2O4 phase was detected. The density of the sintered samples had a tendency to increase with increasing sintering temperature up to 1,473 K, which produced the highest density of 98 %. On the other hand, the sample sintered at 1,373 K had the highest micro-hardness of approximately 610 Hv, which is due to much finer grains.
        4,000원
        31.
        2021.12 구독 인증기관 무료, 개인회원 유료
        When luting indirect restorations with dual-cure resin cement (DCRC), excess cement can be easily removed by performing tack cure of DCRC for a few seconds. The purpose of this study was to evaluate whether different tack cure times affect polymerization shrinkage (PS) of the selected DCRC. One dual-cure resin cement (G-CEM LinkAce, GC) was used for measuring PS in light-cure (LC group), self-cure (SC group), and two tack-cure modes. In the first tack-cure subgroup, tack cure was performed for 1, 2, 3, and 5 seconds, followed by light cure after 2 minutes of remnant removal time in each case (TC-LC groups). In the other tack-cure subgroup, tack cure was performed for the same lengths of time, but followed by self-cure in each case (TC-SC groups). PS was measured by a modified bonded disc method for 1,800 seconds. One-way analysis of variance followed by Duncan’s post hoc test was used to determine any statistically significant differences among the test groups (α = 0.05). When the DCRC was selfcured after tack cure, PS was significantly lower than when it was only self-cured (p < 0.05); however, tack cure time did not affect PS (p > 0.05). When the DCRC was light-cured, PS was not affected by tack cure or tack cure time (p > 0.05). Therefore, tack cure within 5 seconds did not negatively affect the final PS when the DCRC was light-cured after cement remnant removal.
        4,000원
        34.
        2021.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        It has been established that the acoustic mode parameters of the Sun and Sun-like stars vary over activity cycles. Since the observed variations are not consistent with an activity-related origin, even Sun-like stars showing out-of-phase changes of mode frequencies and amplitudes need to be carefully studied using other observational quantities. In order to test whether the presumed relations between the global seismic parameters are a signature of the stellar activity cycle, we analyze the photometric light curve of HD 49933 for which the rst direct detection of an asteroseismic signature for activityinduced variations in a Sun-like star was made, using observations by the CoRoT space telescope. We nd that the amplitude of the envelope signi cantly anti-correlates with both the maximum frequency of the envelope and the width of the envelope unless super are-like events completely contaminate the light curve. However, even though the photometric proxy for stellar magnetic activity appears to show relations with the global asteroseismic parameters, they are statistically insigni cant. Therefore, we conclude that the global asteroseismic parameters can be utilized in cross-checking asteroseismic detections of activity-related variations in Sun-like stars, and that it is probably less secure and efective to construct a photometric magnetic activity proxy to indirectly correlate the global asteroseismic parameters. Finally, we seismically estimate the mass of HD 49933 based on our determination of the large separation of HD 49933 with evolutionary tracks computed by the MESA code and nd a value of about 1:2M and a sub-solar metallicity of Z = 0:008, which agrees with the current consensus and with asteroseismic and non-asteroseismic data.
        4,000원
        35.
        2021.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        It has been known that the global asteroseismic parameters as well as the stellar acoustic mode parameters vary with stellar magnetic activity. Some solar-like stars whose variations are thought to be induced by magnetic activity, however, show mode frequencies changing with di erent magnitude and phase unlike what is expected for the Sun. Therefore, it is of great importance to nd out whether expected relations are consistently manifested regardless of the phase of the stellar magnetic cycle, in the sense that observations are apt to cover a part of a complete cycle of stellar magnetic activity unless observations span several decades. Here, we explore whether the observed relations of the global seismic parameters hold good regardless of the phase of the stellar magnetic cycle, even if observations only cover a part of the stellar magnetic cycle. For this purpose, by analyzing photometric Sun-as-a-star data from 1996 to 2019 covering solar cycles 23 and 24, we compare correlations of the global asteroseismic parameters and magnetic proxies for four separate intervals of the solar cycle: solar minima 2 years, solar minima +4 years, solar maxima 2 years, and solar maxima +4 years. We have found that the photometric magnetic activity proxy, Sph, is an e ective proxy for the solar magnetic activity regardless of the phase of the solar cycle. The amplitude of the mode envelope correlates negatively with the solar magnetic activity regardless of the phase of the solar cycle. However, relations between the central frequency of the envelope and the envelope width are vulnerable to the phase of the stellar magnetic cycle.
        4,000원
        36.
        2021.06 구독 인증기관 무료, 개인회원 유료
        In this article, firstly, we talk about why we respond to “climate change impacts in nature and society” educationally. Secondly, we try to find ways that Jeju also has the ability to halt biodiversity loss and apply nature-based solutions to conserve biodiversity, enhance resilience, and so improve the well-being of the people on the island and in turn to improve the well-being of the people on the planet at the grass roots level of UNESCO internationally protected areas. Thirdly, we try to develop World Environment University Online School Leads Establishment of World Environment University so called “Lead WEU.” We will announce “World Environment University Online School Leads Establishment of World Environment University” at Private Meeting of the 2020 World Conservation Congress on September 9, 2021 in Marseille of France. We propose ”Jeju Global Governance of World Heritage; Climate Change Impacts and Integrated Management of UNESCO internationally Protected Area, at the graduate class of Jeju National University from September 2 to December 9, 2021. The core program centered at the University itself would be developed initially on the basis of the comparative advantage offered by its location in Jeju and the quality of faculty, full and part time, that could be recruited to the University.
        4,000원
        39.
        2020.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In the geochemical field, the chemical speciation of hexavalent uranium (U(VI)) has been widely investigated by performing measurements to determine its luminescence properties, namely the excitation, emission, and lifetime. Of these properties, the excitation has been relatively overlooked in most time-resolved laser fluorescence spectroscopy (TRLFS) studies. In this study, TRLFS and continuous-wave excitation–emission matrix spectroscopy are adopted to characterize the excitation properties of U(VI) surface species that interact with amorphous silica. The luminescence spectra of U(VI) measured from a silica suspension and silica sediment showed very similar spectral shapes with similar lifetime values. In contrast, the excitation spectra of U(VI) measured from these samples were significantly different. The results show that distinctive excitation maxima appeared at approximately 220 and 280 nm for the silica suspension and silica sediment, respectively.
        4,300원
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