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        검색결과 25

        3.
        2022.10 구독 인증기관·개인회원 무료
        When decommissioning a nuclear power plant, the structure must be made to a disposable size. In general, the cutting process is essential when dismantling a nuclear power plant. Mainly, thermal cutting method is used to cutting metal structures. The aerosols generated during thermal cutting have a size distribution of less than 1 μm. The contaminated structures are able to generate radioactive aerosols in the decommissioning. Radioactive aerosols of 1 μm or less are deposited in the respiratory tract by workers’ breathing, causing the possibility of internal exposure. Therefore, workers must be protected from the risk of exposure to radioactive aerosols. Prior knowledge of aerosols generated during metal cutting is important to ensure worker safety. In this study, the physical and chemical properties of the aerosol were evaluated by measuring the number and mass concentrations of aerosols generated when cutting SUS304 and SA508 using the laser cutting method. High-resolution aerosol measuring equipment (HR-ELPI+, DEKATI) was used to measure the concentration of aerosols. The HR-ELPI+ is an impactor-type aerosol measuring equipment that measures the aerosol number concentration distribution in the aerodynamic diameter range of 6 nm to 10 um in real-time. And analyze the mass concentration of the aerosol according to the diameter range through the impactor. ICP-MS was used for elemental mass concentration analysis in the aerosol. Analytical elements were Fe, Cr, Ni and Mn. For the evaluation of physical and chemical properties, the MMAD of each element and CMAD were calculated in the aerosol distribution. Under the same cutting conditions, it was confirmed that the number concentration of aerosols generated from both materials had a uni-modal distribution with a peak around 0.1 um. CMAD was calculated to be 0.072 um for both SUS304 and SA508. The trend of the CMAD calculation results is the same even when the cutting conditions are changed. In the case of MMAD, it was confirmed that SUS304 had an MMAD of around 0.1 μm in size for only Fe, Cr and Mn. And SA508, Fe, Cr, Ni and Mn were all confirmed to have MMAD around 0.1 μm in size. The results of this study show that a lot of aerosols in the range of less than 1 μm, especially around 0.1 μm in size, are generated when metal is cut using laser cutting. Therefore, in order to protect the internal exposure of workers to laser metal cutting when decommissioning NPPs, it is necessary to protect from nano-sized aerosols beyond micron size.
        7.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to identify the structure and characteristics for the reproduction of the armor in the Unified Silla period, and then reproduce and utilize it as a cultural content. In the armor reproduction project excavated from Jaemaejeong, Gyeongju. Jaemaejeong armor is consisting of Singap (身甲, body armor), Sanggap (裳甲, hip armor), and Sangbakgap (上膊甲, upper arm armor) at the time of excavation. Unlike the armor of the Three Kingdoms period, Singap and Sanggap are separated. Singap is Yangdangsik (裲襠式, side opening method) and Gyunggap (頸 甲, gorget) was not unearthed, Sangbakgap was divided into a part that protects the left and right upper arms and a part that protects the chest, so that the unexcavated head and neck cover of the helmet can be protected to the shoulder. In addition, in the case of Chalgap (札甲, lamellar armor), the Oejungsik (外重式, folded from outside to inside) is mainly used, but it is peculiar that Naejungsik (內重式, folded from inside to outside) is used in Sangbakgap of Jaemaejeong armor. It is presumed that this was used as a method to ensure that the armor were closely attached to the human body. In order to design with the parade armor of Gochwidae in Gyeongju based on the reproduced Jaemaejeong armor, the designer’s imagination and historical work of the times were involved due to the characteristics of performance costumes. Reproduced armor as a cultural content should be considered indispensable to simplify and lighten clothing suitable for performances based on the excavated historical armor.
        4,300원
        10.
        2018.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We report the structural, morphological and magnetic properties of the Ni70Mn30 alloy prepared by Planetary Ball Mill method. Keeping the milling time constant for 30 h, the effect of different ball milling speeds on the synthesis and magnetic properties of the samples was thoroughly investigated. A remarkable variation in the morphology and average particle size was observed with the increase in milling speed. For the samples ball milled at 200 and 300 rpm, the average particle size and hence magnetization were decreased due to the increased lattice strain, distortion and surface effects which became prominent due to the increase in the thickness of the outer magnetically dead layer. For the samples ball milled at 400, 500 and 600 rpm however, the average particle size and hence magnetization were increased. This increased magnetization was attributed to the reduced surface area to volume ratio that ultimately led to the enhanced ferromagnetic interactions. The maximum saturation magnetization (75 emu/g at 1 T applied field) observed for the sample ball milled at 600 rpm and the low value of coercivity makes this material useful as soft magnetic material.
        4,000원
        12.
        2011.11 구독 인증기관 무료, 개인회원 유료
        바다에 기름오염 사고가 발생하면 여러 가지 방제 방법 중 물리적 회수 방법을 우선적으로 사용하고 유처리제는 최후 수단으로 고려하는 경향이 있다. 유처리제는 수중으로 기름이 신속히 분산되도록 하여 해수면으로부터 제거하는 방법이다. 해수면으로부터 신속히 기름을 제거하는데 대한 유처리제의 효용성은 널리 증명되어 왔으나 아직도 대부분의 국가들은 해양환경에 미치는 독성을 우려하여 적극적인 사용을 하지 않고 있는 실정이다. 보고된 자료에 의하면 유처리제 사용 후 수중생물에 대한 독성은 발견되지 않았으며, 유처리제와 혼합된 기름이 기 름 그 자체보다 독성이 더 크게 나타나지 않았다. 멕시코만 기름유출 사고 시 미국 정부와 BP사는 최대한 해안에 기름이 도달하지 않는데 중 점을 두고 해수면뿐만 아니라 수중의 기름에 대해서도 유처리제를 사용하였다.
        3,000원
        13.
        2011.11 구독 인증기관·개인회원 무료
        In order to isolate thermophilic compost-promoting bacteria with high activity of cellulase and xylanase, spent mushroom substrates with sawdust were collected from mushroom cultivation farm, Jinju, Gyeongnam in Korea. Among of the isolates, one strain, designated HJ01 was selected by agar diffusion method. The strain HJ01 was identified as members of the Bacillus subtilis by biochemical characteristics using Bacillus ID kit and VITEK 2 system. Comparative 16S rDNA gene sequence analysis showed that strain HJ01 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus subtilis with 16S rDNA gene sequence similarity of 99.3%. On the basis of its physiological properties, biochemical characteristics and phylogenetic distinctiveness, strain HJ01 was classified within the genus Bacillus, for which the name Bacillus subtilis HJ0 is proposed. The cellulase and xylanase activity of B. subtilis HJ0 was slightly increased according to bacterial population from exponential phase to stationary phase in growth curve for B. subtilis HJ01.
        15.
        2009.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        핵연료 운반용 실린더의 재사용을 위한 용기세척공장의 제염공정에 대한 성능을 평가하기 위하여 Na2CO3 + H2O2 혼합용액의 조합을 약간 달리한 2회의 시험을 실행하였다. 각 시험은 모두 일련의 5 단계에 걸쳐 실시되었다. 우라늄 제염의 주 화학종은 Na4UO2(CO3)3 로 식별되었다. 그리고 첫 단계에서의 세척액은 물이었으며, 이 단계에서 50% 이상의 우라늄이 제염되었다. 그 이후로는 단계가 더해 갈수록 우라늄의 제염양은 지수함수적으로 감소하는 경향을 나타내었으며, 화학양론적으로 제거된 우라늄에 비하여 투여된 Na2CO3 의 양은 과다함을 나타내었다. 이러한 결과들에 의하면, 공정최적화를 통하여 Na2CO3 의 투여량 감축, 세척폐액의 감량, 제염단계 축소 등을 꾀할 수 있을 것으로 판단된다.
        4,000원
        16.
        2007.04 KCI 등재 구독 인증기관·개인회원 무료
        Human saliva contains a large number of proteins and peptides whose composition may alter as a consequence 。f disease. To date. however‘ the proteins and peptides that routinely populate thi s ora l fluid a re largely unknown To provide a catalogue of saliva proteins, we have surveyed the unstimulated human whole saliva by us ing shotgun proteornics. For the shotgun approach, whole saliva proteins were digested into peptides with ChemDigestD ‘ and the resul ting peptide fragments were separated by RP-HPLC, followed by each fraction was t ryptic digestion. ChemDigestD-Trypsin digested peptides were analyzed by tandem mass spectrometry(MS/MS) us ing a nano-LC eq 버 pped quadrupole-time of f1ight mass spectrometer, and the obtained spectra were searched against human protein seq uence data base using MASCOT. Shotgun proteomics allowed a total of 291 human pr。 teins to be confidently assigned . The largest group(17 .2%) of the identified proteins sorted into functional catego ries was included in t he signal t ransduction funct ion except for the hypothetical 0 1' unknown function. This work provides a valuable s ta rting point for the analysis of human salivary proteins and their biological functions and candidates from human whole sali va that may prove to be of diagnostic and therapeutic significance
        17.
        2007.04 KCI 등재 구독 인증기관·개인회원 무료
        The human ELAV(embryonic lethal abnormal vision)-like protein HuR stabilizes a certain group of cellular mRNAs that contain AU- ri ch elements in theil‘ 3’• untranslated region, Dysregulation of mRNA s tability may be relevant in tumor biology and may lead to abnormal expression of several proteins in malignant tumors, The aim of this study is to identify the differentially expressed proteins according to the functi onal activi ty of HuR Methods : We used stabl e expression of small interfering RNA(siRNA) of HuR gene to inhibit the expression of HuR in human ora l car cinoma cell lines‘ KB cell line and YD10B cell line‘ and compared the proteomic changes between s iRNA-treated and cont rol cell line using two-dimensional gel electrophoresis , Flow cytometry caliber scan(FACS) was employed to investigate the effects of HuR on cell apoptosis and proliferation , Results: Seventeen differentially expressed proteins between the two cell lines were identified by electrospray ioruzati on quadrupole time-of- fl ight mass spectrometry(ESI-Q-TOF MS) and database searching, Among them there are eleven proteins which are significant ly up- regulated in siRNA- treated cell line, which include heat shock protein 10(influencing nucl eocytoplas rnic transpo 다, cell dedifferentiation , and inhibition of apoptosis) , keratin 19(basal cell differ ent iat ion) ‘ and nucleoside diphosphate kinase B(G protein activator), etc Enolase 1 and Ml of pyruvate kinase a re the representatives of signifi cantly down-regulated proteins in siRNA-treated cell 11l1e Conclusion : Our data suggest that HuR participate in mRNAs stability of proteins that have the counter effects in the carcinogenesis of oral ca ncer , And the functiona l proteomics a re needed to elucidate the detailed interactions between HuR and t hese molec ules
        19.
        1994.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        슈퍼요소를 이용한 구조해석은 항공기나 선박 둥 대형구조물의 해석에서 장점올 가지며 하드웨어의 제한된 조건속에서 효과적인 결과를 준다. 본 논문에서는 고정된 타이벡 (tie back) 상태에서 세계 최대의 5α삐톤, 회전 상태에서 3α%톤올 들어 올릴 수 있는 크레인선의 구조 안전성 검토를 위하여 슈퍼요소로 분할된 부분 구조물 해석을 다루었으며, 효과적인 부분구조화 (substructuring) 과정과 독특한 하중추출방법 및 유한요소 모델링 기법을 제시하고 있다. 또한 해 석결과에 근거한 실질적인 구조물의 총괄적 국부보강방법올 보여주고 있다. 대형 크레인선의 구조해석적용 연구를 통하여 부분구조기법의 효율성을 확립하였으며 이러한 해석기법을 통하여 새로운 형태의 유사한 구조물에 대한 해석지침을 제시하고 었다.
        4,000원
        20.
        2020.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The Korean Institute of Technology Satellite (KITSAT-1) is the first satellite developed by the Satellite Technology Research Center and the University of Surrey. KITSAT-1 is orbiting the Earth’s orbit as space debris with a 1,320 km altitude after the planned mission. Due to its relatively small size and altitude, tracking the KITSAT-1 was a difficult task. In this research, we analyzed the tracking results of KITSAT-1 for one year using the Midland Space Radar (MSR) in Texas and the Poker Flat Incoherent Scatter Radar (PFISR) in Alaska operated by LeoLabs, Inc. The tracking results were analyzed on a weekly basis for MSR and PFISR. The observation was conducted by using both stations at an average frequency of 10 times per week. The overall corrected range measurements for MSR and PFISR by LeoLabs were under 50 m and 25 m, respectively. The ionospheric delay, the dominant error source, was confirmed with the International Reference of Ionosphere-16 model and Global Navigation Satellite System data. The weekly basis orbit determination results were compared with two-line element data. The comparison results were used to confirm the orbital consistency of the estimated orbits.
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