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        검색결과 407

        102.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polypyrrole (PPy) decorated on reduced graphene oxide (rGO) films is successfully prepared with pyrrole (Py) monomers and rGO through one-step combining oxidation with polymerization reaction. Compared with the pure individual components, rGO/PPy compound turns out better electrochemical characteristics owing to the introduction of rGO sheets, which improves the specific surface area and the conductivity of composite material. When the amount of rGO is 10% of the total, the rGO/PPy compound delivers the best capacitance of 389.3 F g−1 at 1.0 A g−1 in a three-electrode system and 266.8 F g−1 at 0.25 A g−1 in the symmetric supercapacitor system. In addition, asymmetric device (rGO/PPy//AC) has been successfully fabricated using optimized rGO/PPy compound as positive electrode, activated carbon as negative electrode (AC) and 1 M Na2SO4 aqueous solution as electrolyte. The device obtains long cycle stability under the high-voltage region from 0 to 1.6 V, meanwhile displaying the satisfied energy density of 19.7 Wh kg−1 at 478.1 W kg−1. Besides, the rGO/PPy//AC device presents satisfactory rate capability and long life time.
        4,000원
        103.
        2020.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this paper, AgCl/Ag3PO4/diatomite photocatalyst is successfully synthesized by microemulsion method and anion in situ substitution method. X-ray diffraction (XRD), photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and ultraviolet-visible spectroscopy (UV-Vis) are used to study the structural and physicochemical characteristics of the AgCl/Ag3PO4/diatomite composite. Using rhodamine B (RhB) as a simulated pollutant, the photocatalytic activity and stability of the AgCl/Ag3PO4/diatomite composite under visible light are evaluated. In the AgCl/Ag3PO4/diatomite visible light system, RhB is nearly 100 % degraded within 15 minutes. And, after five cycles of operation, the photocatalytic activity of AgCl/Ag3PO4/diatomite remains at 95 % of the original level, much higher than that of pure Ag3PO4 (40 %). In addition, the mechanism of enhanced catalytic performance is discussed. The high photocatalytic performance of AgCl/Ag3PO4/diatomite composites can be attributed to the synergistic effect of Ag3PO4, diatomite and AgCl nanoparticles. Free radical trapping experiments are used to show that holes and oxygen are the main active species. This material can quickly react with dye molecules adsorbed on the surface of diatomite to degrade RhB dye to CO2 and H2O. Even more remarkably, AgCl/Ag3PO4/diatomite can maintain above 95 % photo-degradation activity after five cycles.
        4,000원
        104.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Heteroatoms in situ-doped hierarchical porous hollow-activated carbons (HPHACs) have been prepared innovatively by pyrolyzation of setaria viridis combined with alkaline activation for the first time. The micro-morphology, pore structure, chemical compositions, and electrochemical properties are researched in detail. The obtained HPHACs are served as outstanding electrode materials in electrochemical energy storage ascribe to the particular hierarchical porous and hollow structure, and the precursor setaria viridis is advantage of eco-friendly as well as cost-effective. Electrochemical measurement results of the HPHACs electrodes exhibit not only high specific capacitance of 350 F g−1 at 0.2 A g−1, and impressive surface specific capacitance (Cs) of 49.9 μF cm−2, but also substantial rate capability of 68% retention (238 F g−1 at 10 A g−1) and good cycle stability with 99% retention over 5000 cycles at 5 A g−1 in 6 M KOH. Besides, the symmetrical supercapacitor device based on the HPHACs electrodes exhibits excellent energy density of 49.5 Wh kg−1 at power density of 175 W kg−1, but still maintains favorable energy density of 32.0 Wh kg−1 at current density of 1 A g−1 in 1-ethy-3-methylimidazolium tetrafluoroborate ( EMIMBF4) ionic liquid electrolyte, and the excellent cycle stability behaviour shows the nearly 97% ratio capacitance retention of the initial capacitance after 10,000 cycles at current density of 2 A g−1. Overall, the results indicate that HPHACs derived from setaria viridis have appealing electrochemical performances thus are promising electrode materials for supercapacitor devices and large-scale applications.
        4,600원
        105.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Food and agricultural production sector, especially livestock production is vital for Mongolia’s economic and social development. Domestic sheep play key roles for Mongolians, providing food (meat, milk) and raw materials (wool, sheepskin), but genetic diversity, origin of sheep populations in Mongolia have not been well studied. Studies of population genetic diversity is important research field in conservation and restoration of animal breeds and genetic resources. Therefore, this study aimed to investigate genetic characteristics and estimate origin through the analysis of mitochondrial DNA control region D-loop and Cytochrome b of Mongolian indigenous sheep (Mongolian native, Orkhon and Altanbulag) and one Europe sheep (Suffolk). As a result of there were found, 220 SNPs (Single nucleotide polymorphism) in the D-loop region, 28 SNPs in the Cytochrome B region, furthermore, 77 Haplotypes. The nucleotide diversity was only found in D-loop region (n = 0.0184). Phylogenetic analysis showed that 3 (A, B, and C) of 5 haplogroups of sheep have been identified in our research. Haplogroup C was only found in Mongolian indigenous sheep. Haplogroup D and E were not observed. As a result of haplogroups, haplogroup A was dominant (n = 46 of 94 sheeps), followed by haplogroup B (n = 36) and haplogroup C (n = 12). Sequence analysis showed that T deletion, insertion and heteroplasmy in D-loop region occurred at a high rate in Mongolian indigenous sheep population (T insertion = 47, T deletion = 83). The heteroplasmy, which has never been found in Mongolian sheep, has been newly discovered in this study. As a result, the Mongolian sheep varieties, which mainly derived from Asia, were in hybridization with European sheep varieties.
        4,000원
        106.
        2020.06 구독 인증기관 무료, 개인회원 유료
        Foodborne disease caused by pathogenic bacteria is one of main concerns in food industry. To supply safe food products, chemical and thermal intervention technologies have been widely applied in food industry, however these treatments have their own limitations. The concept of biopreservation has recently received increased attention in response to industrial and consumer demands. The biopreservation technologies mainly include bacteriocin, bacteriophage, bacteriophage-encoded enzymes, and endolysins. Among them, bacteriocins have been widely recognized as a main biopreservative and have also been most studied. Bacteriocins, mainly consisting of antibacterial peptides, may have bactericidal or bacteriostatic effect which could prolong the shelf-life as well as maintain safety of foods. This review article offers a brief research trend about bacteriocins, focusing on microbial food safety. The antimicrobial mechanism of bacteriocins has been discussed and some efforts to inactivate foodborne pathogens have been analyzed in this review article. The challenges facing the application of bacteriocins have also been evaluated. Thus, this review will provide insights for researchers working in bacteriocin as well as industry personnel looking for a new method for fighting foodborne pathogens.
        4,000원
        107.
        2020.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Augmented somatosensory feedback stimulates the mechanoreceptor to deliver information on bodily position, improving the postural control. The various types of such feedback include ankle-foot orthoses (AFOs) and vibration. The optimal feedback to mitigate postural sway remains unclear, as does the effect of augmented somatosensory feedback on muscle co-contraction. Objects: We compared postural sway and ankle muscle co-contraction without feedback (control) and with either of two forms of somatosensory feedback (AFOs and vibration). Methods: We recruited 15 healthy subjects and tested them under three feedback conditions (control, AFOs, vibration) with two sensory conditions (eyes open, or eyes closed and the head tilted back), in random order. Postural sway was measured using a force platform; the mean sway area of the 95% confidence ellipse (AREA) and the mean velocity of the center-of-pressure displacement (VEL) were assessed. Co-contraction of the tibialis anterior and gastrocnemius muscles was measured using electromyography and converted into a cocontraction index (CI). Results: We found significant main effects of the three feedback states on postural sway (AREA, VEL) and the CI. The two sensory conditions exerted significant main effects on postural sway (AREA and VEL). AFOs reduced postural sway to a level significantly lower than that of the control (p = 0.014, p < 0.001) or that afforded by vibration (p = 0.024, p < 0.001). In terms of CI amelioration, the AFOs condition was significantly better than the control (p = 0.004). Vibration did not significantly improve either postural sway or the CI compared to the control condition. There was no significant interaction effect between the three feedback conditions and the two sensory conditions. Conclusion: Lower-extremity devices such as AFOs enhance somatosensory perception, improving postural control and decreasing the CI during static standing.
        4,000원
        108.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon materials with tailorable structures and superior properties have great potential applications in environmental protection, energy conversion, and catalysis. Plant biomass as abundant and green non-toxic raw materials has been considered as good precursors for synthesizing heteroatom-doped carbon materials. However, few studies have been reported on the different natures of carbon materials derived from different parts of the same plant biomass. In this study, we prepared carbon materials from the petioles and blades of apricot leaves by direct pyrolysis without additives. Detailed characterizations indicate that these two carbon materials are similar in element composition and graphitization degree, but differ greatly in surface area and pore volume. These differences can be attributed to the different contents of inorganic salts, vascular bundles, and proteins in petioles and blades. When used as catalysts for the oxidation of ethylbenzene, the petiole-derived carbon shows better catalytic performance than the blades derived carbon due to its high surface area, large average pore size, and doped nitrogen atoms. Furthermore, the carbon catalysts derived from the petioles and blades of poplar leaves and parasol tree leaves show the same difference in catalytic reaction, implying that the above-mentioned conclusion is rather universal, which can provide reference for the synthesis of carbon materials from leaves.
        4,000원
        109.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Introduction: Age-related co-morbidities are common among persons living with chronic Human Immunodeficiency Virus (HIV). However, data are largely absent on the relationship between frailty and incontinence as related to falls—common age-related co-morbidities—among people living with chronic HIV (PLWH). Methods: To inform hospital-based Occupational Therapy (OT) services for PLWH, we performed a case-control study using extracted data from the electronic medical records of PLWH who had received OT at a large academic hospital. Two-hundred-and-four subjects were included in the final dataset; sixty-eight were cases that reported a fall within the last 12 months, while 136 were controls which were PLWH who had not sustained a fall. Results: The association between falls and frailty indicated that persons categorized as ‘pre-frail’ with balance deficits were more likely to fall (OR=2.77 [1.18-6.52]). Women who lacked insurance were less likely to fall (OR=0.38 [0.18-0.82]) and (OR=0.29 [0.09-0.88]) respectively. The association between incontinence and falls among PLWH were not statistically significant in a multivariate adjusted regression model (OR=1.38 [.59-3.22]). Conclusion: Our findings suggest further examination of the person factors of PLWH who are categorized clinically as ‘pre-frail’ or ‘frail’ may improve health outcomes and reduce falls when paired with occupation-based interventions.
        4,600원
        110.
        2020.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Lysyl oxidase-variant 2 (LOX-v2) is a novel variant of lysyl oxidase (LOX) that functions as an amine oxidase for the formation of lysine-mediated crosslinks found in collagen and elastin fibrils. In addition to the amine oxidase activity in the extracellular matrix, several novel functions, such as tumor suppression, tumor progression, chemotaxis, cellular senescence, and modification of histones, have been assigned to LOX. In recent years, it has been reported that LOX is also present in nuclear locations, suggesting a novel functional role of LOX in the nucleus. To test the amine oxidase activity of LOX and LOX-v2 to nuclear histone proteins, we expressed and purified LOX and LOX-v2 as recombinant forms and then assessed the amine oxidase activity toward histone H2A in in vitro peroxidase-coupled fluorometric assays. Both LOX and LOX-v2 proteins showed significant levels of amine oxidase activity toward histone H2A in a β -aminopropionitrile-inhibitable manner. In immunofluorescence staining after ectopic expression in cultured cells, LOX was observed in the perinuclear, cytoplasmic, and extracellular areas, whereas LOX-v2 was predominantly detected in the nucleoplasm with a punctuate pattern. These findings suggest that LOX-v2 may play a novel functional role in the nucleus through the amine oxidase activity to the nuclear histone proteins. Elucidation of the specific functional roles of LOX-v2, such as substrate specificity toward different types of nuclear proteins and detailed analysis on subnuclear localization, will provide a significant clue in understanding the diverse functional roles currently assigned to a single enzyme, LOX.
        4,000원
        111.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Energy and environmental are always two major challenges for the sustainable development of the modern human being. For avoiding the serious environmental pollution caused in the fabrication process of porous carbon, a popular energy storage material, we reported a facile, green and activating agent free route hereby directly carbonizing a special biomass, Glebionis coronaria. A nitrogen doped hierarchical porous carbon with a specific surface area of up to 1007 m2 g−1 and a N doping content of up to 2.65 at.% was facilely fabricated by employing the above route. Benefiting from the peculiarly hierarchical porous morphology, enhanced wettability and improved conductivity, the obtained material exhibits superior capacitance performance, which capacitance reaches up to 205 F g−1 under two-electrode configuration, and no capacitance loss is observed after 5000 cycles. Meanwhile, the capacitance retention of the obtained material arrives up to 95.0% even under a high current density of 20 A g−1, illuminating its excellent rate capability. The fabricated nitrogen-doped hierarchical porous carbon with larger capacitance than commercial activated carbon, excellent rate capability and cycle stability is an ideal cost-efficient substitution of commercial activated carbon for supercapacitor application.
        4,000원
        112.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present work introduces a new method for the recycling of waste flocculation sludge to prepare electrode materials for supercapacitor. Hazardous azo dye was removal from textile dying wastewater by a new chitosan-based flocculant, and the generated dye sludge flocs was used as a nitrogen-containing precursor for the fabrication of N-doped carbon materials. The influence of azo dye on specific surface areas, nitrogen content, pore evolution of the resulting products and their electrochemical performance were investigated in detail. The results demonstrated a dual role of azo dye worked as both a nitrogen resource and pore-forming agent. The resulting N-doped carbon nanosheets derived from azo dye flocs demonstrated high electrochemical capacitance and good stability for supercapacitor electrode, which is attributed to the unique nitrogen doping, higher specific surface area and efficient charge transfer ability.
        4,000원
        113.
        2019.10 구독 인증기관 무료, 개인회원 유료
        독일 괴팅겐 대학교 동아시아 연구소 한학과 학생들은 첫 해에 번체자를 배우고, 다음 학년 학기에는 번체자를 계속 쓰거나 간체자로 전환하는 것 둘 중 하나를 선택할 수 있도록 규정하고 있다. 간체자를 선택한 학생은 이 때 쓰기에서 번체를 간체자로 전환하는 것을 학습하였는데, 이 때 이들만의 독특한 한자 오류가 나타남을 확인할 수 있다. 예를 들어, 전에 배운 번체자의 영향을 받아 여행을 뜻하는 간체자 旅游를 번체자인 旅遊로 쓰거나, 亲眼을 親見眼 으로 쓰는 것과 같은 예이다. 필자는 이 전환 시기에 출현한 한자 쓰기 오류가 외국 국적의 학습자가 범하는 오류와 상이함을 발견하였고, 이것이 필자의 연구 동기가 되었다. 본 연구는 중국어를 학습한 독일 국적 학습자들이 번체자에서 간체자로 한자 사용이 전환되는 시기에 발생하는 다양한 한자 오류 현상을 위주로 연구를 진행하였다. 대상은 독일 괴팅겐대학교 동아시아 연구소의 한학과 학생이었으며, 연구 자료는 대상 학습자가 매주 한 편씩 지은 글 총 42편을 대상으로 하였다. 본 연구의 문제의식은 두 가지이다. 하나는 '이러한 과도기에 생긴 한자 오류 현상은 무엇?'이며, '먼저 번체자 학습을 완료한 학습자가 다시 간체자를 학습할 경우, 건의할 학습 방법이 어떤 것이 있는가?'이다. 연구 절차는 대상 학생이 간체자를 이용하여 한 달 내에 쓴 글을 수집하고 쓰기에서 나타난 한자 오류들을 분석하여 귀납하는 방법을 사용하였으며, 마지막으로 이를 토대로 교학 건의를 도출하였다. 연구 결과는 다음과 같다. 한자 오류 유형은 필기오류, 부건 오류, 同音字와 音近字의 잘못된 대체 오류, 번체자의 잘못된 대체 오류, 그 외 다양한 종류의 기타 오류들이다.
        5,500원
        116.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Motile aeromonad septicaemia (MAS) mostly caused by Aeromonas hydrophila is a disease of high economic impact in freshwater organism. This study examined the seroconversion and seroprotection of formalinised local isolates of Aeromonas hydrophila in the Clarias gariepinus administered via different routes. Highly virulent Aeromonas hydrophila was treated with 40v/v formalin for 24 h. Bacterin was suspended to 0.5 McFarland standard and utilized to immunize Clarias gariepinus of 400±20 g in three groups with 50 samples each via three routes of administration. Antibody measurement taken at regular intervals before and after vaccination revealed a significantly higher antibody values in all routes compared to the control and difference was noticed at all intervals. Relative percent survival was 71.43, 62.86 and 57.14 intraperitoneal, intramuscular and immersion routes, respectively. Correlation analysis established a strong and direct relationship in the antibody generation through route of administration and efficacy of vaccine. This local vaccine was able to confer a high degree of immunity on Clarias gariepinus and can therefore be used to vaccinate against MAS.
        4,000원
        117.
        2019.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We develop forecast models of daily probabilities of major flares (M- and X-class) based on empirical relationships between photospheric magnetic parameters and daily flaring rates from May 2010 to April 2018. In this study, we consider ten magnetic parameters characterizing size, distribution, and non-potentiality of vector magnetic fields from Solar Dynamics Observatory (SDO)/Helioseismic and Magnetic Imager (HMI) and Geostationary Operational Environmental Satellites (GOES) X-ray flare data. The magnetic parameters are classified into three types: the total unsigned parameters, the total signed parameters, and the mean parameters. We divide the data into two sets chronologically: 70% for training and 30% for testing. The empirical relationships between the parameters and flaring rates are used to predict flare occurrence probabilities for a given magnetic parameter value. Major results of this study are as follows. First, major flare occurrence rates are well correlated with ten parameters having correlation coefficients above 0.85. Second, logarithmic values of flaring rates are well approximated by linear equations. Third, using total unsigned and signed parameters achieved better performance for predicting flares than the mean parameters in terms of verification measures of probabilistic and converted binary forecasts. We conclude that the total quantity of non-potentiality of magnetic fields is crucial for flare forecasting among the magnetic parameters considered in this study. When this model is applied for operational use, it can be used using the data of 21:00 TAI with a slight underestimation of 2–6.3%.
        4,300원
        118.
        2019.07 구독 인증기관 무료, 개인회원 유료
        This study aimed to identify the key factors influencing the U.S. millennial consumers’ willingness to recycle their denim apparel to brands or retailers. Consumer perceived value model provides the theoretical framework and guides data analysis. Five main values identified are the perceived social, financial, emotional, convenience and ecological values.
        4,000원