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        검색결과 1,232

        161.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Rare earth magnets with excellent magnetic properties are indispensable in the electric device, wind turbine, and e-mobility industries. The demand for the development of eco-friendly recycling techniques has increased to realize sustainable green technology, and the supply of rare earth resources, which are critical for the production of permanent magnets, are limited. Liquid metal extraction (LME), which is a type of pyrometallurgical recycling, is known to selectively extract the metal forms of rare earth elements. Although several studies have been carried out on the formation of intermetallic compounds and oxides, the effect of oxide formation on the extraction efficiency in the LME process remains unknown. In this study, microstructural and phase analyses are conducted to confirm the oxidation behavior of magnets pulverized by a jaw crusher. The LME process is performed with pulverized scrap, and extraction percentages are calculated to confirm the effect of the oxide phases on the extraction of Dy during the reaction. During the LME p rocess, Nd i s completely e xtracted a fter 6 h, w hile D y remains as D y2Fe17 and Dy-oxide. Because the decomposition rate of Dy2Fe17 is faster than the reduction rate of Dy-oxide, the importance of controlling Dy-oxide on Dy extraction is confirmed.
        4,000원
        168.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to identify the effect of synovium graft on conjunctiva in rabbits after dry eye induction. Six New Zealand White rabbits were used as dry eye models. Both eyes were divided to two groups as control and synovium graft group. The synovium graft was performed in fourth week after dry eye modeling. Quantitative change of tears through Schirmer tear test (STT), qualitative change of tear film through tear film break up time (TFBUT), and damage of cornea through fluorescein staining were observed for 10 weeks at intervals of two weeks. Histological examination was performed to evaluate cornea and conjunctiva at tenth week. In both groups, STT and TFBUT were significantly decreased in 4 weeks after modeling compared to 0 weeks (p < 0.05) . After synovium graft, there were increases in STT value at 4 weeks and TFBUT at 4 and 6 weeks in graft group (p < 0.05). Corneal fluorescein staining showed no significant difference between the two groups. In histopathological examination, grafted synovium was detected as round to ovoid ingression folds, well attached to grafted regions with 0.11 ± 0.04 mm2 (range, 0.05- 0.16 mm2). These results indicated that the synovium graft on the conjunctiva had an effect on the qualitative and quantitative improvement of the tear film even though there was no histological change.
        4,000원
        169.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Kisspeptin, a neuropeptide and the master controller of reproductive axis upstream to GnRH neurons, and its receptor are also expressed in extrahypothalamic tissues, such as ovaries. As systemic kisspeptin has been shown to modulate follicular dynamics in cattle, we hypothesized that kisspeptin has direct actions on the ovarian follicular development. We also hypothesized that kisspeptin regulation of primordial follicle development is via modulation of VEGF expression. In order to test these hypotheses, we cultured caprine ovarian cortical strips in vitro for 7 days with supplementation of kisspeptin at 1, 10 and 100 μM concentration and observed the development of primordial follicles into intermediate, primary and secondary follicles. We also studied the alteration in the expression profile of VEGF and VEGF transcript variant 2 mRNA during follicular development in the presence of kisspeptin. We confirmed the presence of GPR54 in goat ovaries in our preliminary studies. Supplementation of kisspeptin at 1 and 10 μM concentration facilitated the development of primordial follicles into intermediate, primary and secondary follicles with less number of degenerated follicles while the same at 100 μM resulted in degeneration of follicles. We observed a drastic increase in the expression profile of VEGF and VEGF transcript variant 2 mRNA upon culture which was independent of kisspeptin treatment. In conclusion, our studies show that kisspeptin facilitates ovarian primordial development in vitro.
        4,000원
        170.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We report the structural characterization and electric heating performance of carbon thin films (CTFs), which were prepared from negative-type SU-8 photoresist by deep UV exposure and following carbonization. The prepared CTFs were found to have pseudo-graphitic carbon structures containing partially graphite domains in the amorphous carbon matrix. The CTFs showed a very smooth surface morphology with a roughness of 0.42 nm. The 107 nm-thick CTFs exhibited an excellent electric heating performance by attaining a high maximal temperature of 207 °C and a rapid heating rate of 13.2 °C/s at an applied voltage of 30 V. Therefore, the CTFs prepared in this study can be applied as electrode materials for high-performance electric heaters.
        4,000원
        171.
        2020.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We report the discovery of a giant exoplanet in the microlensing event OGLE-2017-BLG-1049, with a planet―host star mass ratio of q = 9.53 ± 0.39 × 10-3 and a caustic crossing feature in Korea Microlensing Telescope Network (KMTNet) observations. The caustic crossing feature yields an angular Einstein radius of θE = 0.52 ± 0.11 mas. However, the microlens parallax is not measured because the time scale of the event, tE ≃ 29 days, is too short. Thus, we perform a Bayesian analysis to estimate physical quantities of the lens system. We fi nd that the lens system has a star with mass Mh = 0.55+0.36 -0.29 M⊙ hosting a giant planet with Mp = 5.53+3.62 -2.87 MJup, at a distance of DL = 5.67+1.11 -1.52 kpc. The projected star{planet separation is aㅗ = 3.92+1.10 -1.32 au. This means that the planet is located beyond the snow line of the host. The relative lens{source proper motion is μrel ~ 7 mas yr-1, thus the lens and source will be separated from each other within 10 years. After this, it will be possible to measure the flux of the host star with 30 meter class telescopes and to determine its mass.
        4,000원
        172.
        2020.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We investigate the plausibility of mass return, from stellar mass loss processes within the central ~100 pc region of the Milky Way (the inner nuclear bulge), as a mass supply mechanism for the Circumnuclear Disk (CND). Gas in the Galactic disk migrates inward to the Galactic centre due to the asymmetric potential caused by the Galactic bar. The inward migration of gas stops and accumulates to form the central molecular zone (CMZ), at 100{200 pc from the Galactic center. It is commonly assumed that stars have formed in the CMZ throughout the lifetime of the Galaxy and have diffused inward to form a 'r-2 stellar cusp' within the inner nuclear bulge. We propose that the stars migrating inward from the CMZ supply gas to the inner nuclear bulge via stellar mass loss, resulting in the formation of a gas disk along the Galactic plane and subsequent inward migration down to the central 10 pc region (CND). We simulate the evolution of a gas distribution that initially follows the stellar distribution of the aforementioned stellar cusp, and illustrate the potential gas supply toward the CND.
        4,000원
        173.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigated the cytotoxic potential of three different commercially available absorbent feminine hygiene products and one transdermal patch using direct contact and extract exposure methods. Two different cell lines were used – mouse fibroblast L929 and normal human skin fibroblast CCD-986sk cell lines. The test samples were extracted using three different methods in accordance to International Organization for Standardization (ISO). Viability of cells was analyzed using MTT assay and morphology of the cells were also observed using phase contrast microscopy. Overall, the direct contact method using L929 cells showed that all the test samples had no toxic effect when exposed to extracts for 1 h. For the exposure method, no toxic effect was observed in both L929 and CCD986sk cells incubated with all the test samples regardless of the extraction methods used.
        4,000원
        174.
        2020.12 구독 인증기관 무료, 개인회원 유료
        Systematic literature reviews (SLR) are very important to track the extent to which studies related to the formulation of Halal Catering on board have been previously studied by previous scholars. Therefore, the SLR study requires a clear and detailed understanding concerning the study direction for each selected article by analyzing the scope of the study and its dimensions as the main emphasis whether it has been discussed by any previous scholar or otherwise. Through the basis of the analysis of literature reviews will enable the specific detection of the title of the study. Even SLR analysis is also able to compare in terms of the year the article was published by comparing the differences in scope and dimensions of each article by selected scholars referred to 16 scholars from the year 2012 until 2017. Regards to methodology, SLR emphasised into five stages such as i) Time Frame, ii) Selection of a database, iii) Journal selection, iv) Article selection and v) Literature review analysis. Analysis, discussion, and findings will be focusing on the scope, dimensions, and years of studies by using figures, tables as facilitators of analysis and findings. Hence, the role of Halal institutions will be able to assess its ability to form halal rules with the involvement of stakeholders and the scope that has been affected in detail.
        4,000원
        175.
        2020.11 구독 인증기관·개인회원 무료
        Marigold powder is recognized to be a good source of lutein that plays significant roles in promoting the health of eyes and reducing age-related cataract risk. Because lutein cannot be synthesized in a human body, it needs to be supplied from the diet. However, there are no lutein-incorporated food products in a market other than capsules or powders. In this study, the processing performances of marigold powder in a fresh noodle system was investigated in terms of pasting, viscoelastic, and textural properties. In addition, the levels of lutein in the marigold powder-incorporated fresh noodles were quantitatively analyzed before and after cooking by HPLC. The pasting and dynamic viscoelastic parameters of wheat flour were reduced with increasing levels of marigold powder. The SEM images demonstrated that the wheat flour paste samples with higher levels of marigold powder show a highly cellular structure. However, the use of marigold powder at a level of 2% did not significantly affect the tensile properties of fresh noodles. When marigold powder was incorporated into the formulation of fresh noodles, their lutein contents were ranges from 61.22 to 204.91mg/100 g noodles. After cooking, the lutein contents were reduced by almost 50% while they seemed to satisfy the recommended dietary intake of lutein.
        176.
        2020.11 구독 인증기관 무료, 개인회원 유료
        Not only luxury brands, but also fast fashion brands such as ZARA and H&M have successfully opened flagship stores in prime locations such as Ginza, Tokyo. The market-entry strategy via flagship stores appears to be successful, as numerous companies have adopted it. However, for this strategy to work, it is important to consider and verify not only the place, but also the product, price, and promotion aspects. This study systematically investigates the flagship store strategy by comparing the strategies of luxury brands, represented by Chanel and Louis Vuitton, and those of SPA (Specialty store retailer of Private label Apparel) brands, represented by ZARA, developed by the Spanish Inditex Corporation.
        4,600원
        177.
        2020.11 구독 인증기관 무료, 개인회원 유료
        This study considers the process of regional Re-Birth against the depopulation of Teshima, located in the Seto Inland Sea (Tonosho-town, Shodo-district, Kagawa Prefecture). The island was the subject of a scandal with largest illegal industrial waste since the 1970s. Now, the industrial waste issue on the island is mainly removed the ART SETOUCHI, art festival, attracted 150,000 visitors in 2016, and is held once every three years. The study focuses on the effects of ART SETOUCHI (Contemporary art festival) and the regional characteristics (especially focusing on local foods). Based on these two key characteristics, the structure model of Re-Birth aimed CSV, that is, balancing economic value and social value by Value Co-Creation among various actors centered on Local residents and New residents. In this study, Value Co-Creation defines value recognition by Local residents and New residents, based on the concept of value co-creation (4C's approach) by Muramatsu (2015) , S-D-Logic by Vargo and Lush (2004) and S-Logic by Grönroos (2006). This study explores not only the structure model of Re-Birth, but also how to adapt the model even in such harsh environmental areas, like Fukushima, suffering with depopulation, aging, and reputational damage. We see that, Regional Re-Birth means, the story that Local residents and New residents aim to establish the self-government system to have initiatives against the negative state refined as polluted land. At such time, independent, self-reliance, and self-consideration are important factors as condition of Value Co-Creation.
        4,000원
        178.
        2020.11 구독 인증기관·개인회원 무료
        Across several disciplines in the social and behavioral sciences, recent work on reciprocity in social exchange raises questions about exploitativeness, sustainability and environmental concerns (Weiss, 1987; Ursell, 2000; Smit, 2011; Lewis et al., 2015; Grinstein and Riefler, 2015) with calls to research to explore the importance of consumers’ prosocial activities in relation to concepts such as ethnocentrism (Ratner and Miller, 2001; Olivola and Shafir, 2013; Small and Cryder, 2016). Clearly, while the focus of ethnocentrism is on the consumer’s own group, the focus of many calls for prosocial activities is on the “other”. Hence, a question of interest arises from this: how do these competing forces coexist? In other words, since ethnocentrism is a complex multidimensional construct, how do the different dimensions of ethnocentrism relate to prosocial consumer behaviors? Furthermore, since prosocial behaviors are considered necessary, another question of interest is; how can consumers be urged to engage in prosocial behaviors?
        179.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2019년 경기도내 전통시장, 대형마트, 반찬전문점에서 수거한 반찬류의 미생물 품질을 조사하였다. 반찬류 108 건의 식중독 원인균을 검사하였고, 그 중 75건에 대해서는 구매 장소별, 조리 방법별 위생세균 검사를 진행하였 다. 14건(12.9%)에서 Bacillus cereus가 검출되었으며, 나머지 94건에서는 식중독 원인균이 검출되지 않았다. 위생 세균 검사에서 일반세균의 평균 검출량(범위)은 전통시장이 5.8 log CFU/g (3.0-8.2 log CFU/g), 대형마트는 4.3 log CFU/g(2.3-7.8 log CFU/g), 반찬전문점에서는 3.8 log CFU/g (0.0- 6.9 log CFU/g)로 나타났으며, 구입 장소에 따른 유의적인 차이가 있었다(Ρ <0.05). 전통시장의 일반세균수와 대장균 군은 대형마트, 반찬점과 통계적으로 유의한 차이가 있었고, 생채류, 나물류, 볶음류, 젓갈류, 조림류 순으로 일반 세균수와 대장균군이 높게 검출되었다. 콩나물 무침의 보 관온도별 일반세균수의 변화는 냉장보관(4oC)에서는 72시간 경과에서도 큰 변화가 없었으나, 상온보관(20oC) 및 고 온보관(35oC) 시 구입 후 각각 9시간, 6시간 경과 시 부패의 가능성이 제기되어 구입 즉시 냉장보관 할 것을 권장하며, 제품을 판매하는 시설에서도 냉장보관을 하여야 할 것이다.
        4,000원
        180.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present work focused on the determination of texture, morphology, crystallinity, and gas adsorption characteristics of porous graphene prepared from rice husks ashes at different stabilization temperature. The stabilization temperature applied in this work is 100 °C, 200 °C, 300 °C, and 400 °C to convert rice husk into rice husk ashes (RHA). Chemical activation was adopted at temperature 800 °C using potassium hydroxide (KOH) as dehydrating agent at (1:5) impregnation ratio to convert RHA into rice husk ashes-derived graphene (GRHA). The resultant GRHA were characterized in terms of their morphological changes, SSA, crystallinity, and functional group with TEM, the BET method, Raman spectroscopy, and XRD analysis, respectively. Results from this study showed that the SSA of the GRHA at stabilization temperature 200 °C (1556.3 m2/g) is the highest compared to the other stabilization temperature. Raman spectroscopy analysis revealed that all GRHA samples possess D, G, and 2D bands, which confirm the successful synthesis of the rice husks into porous graphene-like materials, known as GRHA. Appearance of diffraction peak in XRD at 44.7° indicating the graphitic structure of all the GRHA samples. Meanwhile, the TEM images of GRHA200 exhibited wrinkled structures due to the intercalation of oxygen and a few layers of graphene flakes. These wrinkled structures and graphene layers are the other factors that lead to the highest SSA of GRHA200 compared to other prepared samples GRHA. Furthermore, the adsorption capacity of CH4 for GRHA200 is up to 43 cm3/g at 35 bar and ambient temperature, almost double the adsorption capacity performance of GRHA400 at the same operating pressure and temperature.
        4,000원