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        검색결과 9

        1.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to investigate the ELF-MF emissions from UCLs and to compare the ELF-MF emission levels of HVTLs and UCLs. In addition, this study proposes a method and management plan to investigate the effects of exposure to ELF-MF emissions from UCLs. The ELF-MF emissions from the 154 kV UCL were 15.4±24.4 (GM: 7.8)mG, while from the 345 kV line they were 6.0±2.4 (GM: 5.7)mG. Through the comparison between ELF-MF emissions of 154 kV UCL and HVTL, at about 20 m distance from an overhead line the emissions level is 4 mG, while from an underground line at about 10 m distance the emission level was recorded as less than 4 mG. Through comparing the ELF-MF emission amount of the UCL according to the burial method, it was found that the direct ELF-MF emission levels are 15.3±7.4 (GM: 13.9)mG at the direct point, in the conduit type 21.0±30.4 (GM: 10.8)mG, and in the buried form 8.5±12.3 (GM:5.1)mG. In this study, ELF-MF emissions were about 37.0% and 47.5% lower, respectively, compared with the direct power and conduit type. The correlation between ELF-MF emission (mG) and power load (A) was analyzed. The higher the power load, the higher the ELF-MF emission. The correlation between ELF-MF emission at the direct point and depth of the UCL was also analyzed, and it was found that as the depth of line burial increased, ELF-MF emissions decreased.
        4,000원
        2.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated Extremely Low Frequency-Magnetic Fields (ELF-MF) exposure levels among housewives for a 24-Hour activity pattern to identify related factors for the exposures. To achieve the objective of the study, we surveyed ELF-MF levels using EMDEX II in a living environment from January to December 2016. We also made subjects write a Daily Activity Pattern in order to identify durations for staying and related information in the environment of exposures. Subjects showed that they spent the longest time in sleep and at home, at 487.5 minutes (KOSIS: 479.0 minutes) and 472.1 minutes (KOSIS: 428.0 minutes), respectively. Furthermore, the 24- hour time-weighted average (TWA) of 54 housewives was 1.24 ± 3.48 mG (GM: 0.52 mG). The ELF-MF exposure levels for all Multiuse Facilities were far below the recommended standards of EMF Guideline Korea and ICNIRP. Thus, these results will provide useful data for the determination of ELF-MF management and reduction methods in living environments.
        4,000원
        3.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lithium silicate, a lithium-ion conducting ceramic, is coated on a layer-structured lithium nickel manganese oxide (LiNi0.7Mn0.3O2). Residual lithium compounds (Li2CO3 and LiOH) on the surface of the cathode material and SiO2 derived from tetraethylorthosilicate are used as lithium and silicon sources, respectively. Powder X-ray diffraction and scanning electron microscopy with energy-dispersive spectroscopy analyses show that lithium silicate is coated uniformly on the cathode particles. Charge and discharge tests of the samples show that the coating can enhance the rate capability and cycle life performance. The improvements are attributed to the reduced interfacial resistance originating from suppression of solid-electrolyte interface (SEI) formation and dissolution of Ni and Mn due to the coating. An X-ray photoelectron spectroscopy study of the cycled electrodes shows that nickel oxide and manganese oxide particles are formed on the surface of the electrode and that greater decomposition of the electrolyte occurs for the bare sample, which confirms the assumption that SEI formation and Ni and Mn dissolution can be reduced using the coating process.
        4,000원
        4.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        According to the regulations of the Korean Animal and Plant Quarantine Agency (QIA), offals include a greater diversity of internal organs than do those of other nations. The present study was conducted to investigate the microbiological quality of diverse edible offal products from pig and cattle slaughterhouses in Korea by performing aerobic plate counts (APCs) and E. coli counts. There were significant differences in E. coli values between red offal and white offal in both pigs and cattle. Significant differences in APCs were also observed between partial red offal and white offal of pigs (P < 0.05). However, no significant differences in APCs between red offal and white offal of cattle. The most frequently detected foodborne pathogen was Staphylococcus aureus (5.6% prevalence in pig offal and 12.5% % prevalence in cattle offal) followed by Clostridium perfringens (11.1 and 7.1%, respectively) and Salmonella (5.6% and 7.1%, respectively). None of the offal samples tested positive for E. coli O157:H7.
        4,000원
        5.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, ELF-MF levels of subway trains were measured to understand the status of the intensity of ELFMF. The measurement points for the train are selected in the center of each train compartment(pantagraph compartment, motor-driven compartment and the compartment that is not connected to any other electric equipment) using EMDEX II. ELF-MF levels of trains were measured from the starting to the terminal station in each lines(Seoul line 1-9, Incheon line 1, Incheon international airport line, Gyungui line, Bundang line, Gyeongchun line, Joongang line, Suin line). We found that the mean and range of ELF-MF levels in the DC power subway train are 2.4 and 0.1~125.9 mG, respectively, while the mean and range of ELF-MF levels in the AC power subway train are 10.4and 0.0~156.3 mG, respectively. Furthermore, the maximum ELF-MF level(156.3 mG) was lower than the reference level(ICNIRP 833 mG, 60Hz). The findings of this study in relation to the characteristics of ELF-MF for subway will be useful to derive the ELF-MF exposure coefficient from our living environment in a subsequent study.
        4,000원
        6.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cathode materials and their precursors are prepared with transition metal solutions recycled from the thewaste lithium-ion batteries containing NCM (nickel-cobalt-manganese) cathodes by a H2 and C-reduction process. Therecycled transition metal sulfate solutions are used in a co-precipitation process in a CSTR reactor to obtain the tran-sition metal hydroxide. The NCM cathode materials (Ni:Mn:Co=5:3:2) are prepared from the transition metal hydroxideby calcining with lithium carbonate. X-ray diffraction and scanning electron microscopy analyses show that the cathodematerial has a layered structure and particle size of about 10 µm. The cathode materials also exhibited a capacity ofabout 160 mAh/g with a retention rate of 93~96% after 100 cycles.
        4,000원
        7.
        2010.10 구독 인증기관·개인회원 무료
        This study is based on specimens which had been collected from Jeollabuk-do, Chungcheonbuk-do and Gyeonsangnam-do provinces in July 1994 through September 2009. As a result of this study, Cunaxa potchensis and C. mageei were identified and newly recorded from Korea.
        8.
        2006.06 KCI 등재 구독 인증기관·개인회원 무료
        β-Hydroxy-β-methylglutaryl coenzyme A reductase(HMG-CoA reductase, E.C. 1.1.1.34) is known to be rate-limiting enzyme in cholesterol biosynthesis. HMG-CoA reductase inhibitor is very useful in the remedy or precaution of hyperlipidemia. The methanol extracts of Pholiota adiposa ASI 24018 showed the highest HMG-CoA reudctase inhibitory activity of 55.8%. The HMG-CoA reductase inhibitor of Pholiota adiposa ASI 24018 was maximally extracted when it was treated with methanol at 30℃ for 12hrs. After purified the HMG-CoA reductase inhibitor by systematic solvent extraction, LH-20 gel column chromatography and RP-HPLC, finally obtained the HMG-CoA reductase inhibitor with an activity of IC50 6.8ug. Molecular weight of the purified HMG-CoA reductase inhibitor was 765.4Da by LC-Mass, NMR, FT-IR, UV spectrometry.