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        검색결과 1,442

        381.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study aims to use asphaltene particles (As) extracted from natural bitumen to synthesize activated carbon (ACAs). The asphaltene particles were mixed with a fixed weight of potassium hydroxide (KOH) as an activating agent, preheated to 600 °C, and then treated with 15% hydrofluoric acid (HF). The methylene blue (MB) 20 mg/l was used to determine the adsorption capacity of ACAs and reactivated carbon (RACAs). The morphology of ACAs and its components were characterized using scanning electron microscopy–energy dispersive X-ray (SEM–EDX) and Fourier-transform infrared spectroscopy (FTIR). The study included the application of adsorption isotherms Freundlich and Langmuir on the experimental data of the studied systems. The yield of ACAs was 92% of the raw material. The activated carbon displayed high adsorption capacity and can be reprocessed after reactivation using microwave radiation. The active surface area of ACAs is found to be 970 m2/g. The effectiveness and adsorption ability of ACAs and RACAs, as proven by its adsorption capacity (218.15 and 217.907 mg/g) for MB, demonstrate that ACAs and RACAs have a large external surface area and an extensive array of pores. The ACAs are most sensitive at 30 °C and neutral pH. The results also showed that the isotherms have a good fit to the experimented data.
        4,000원
        382.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Wood sawdust from an invasive arboreal species, Parkinsonia aculeata, and seeds from a tropical fruit of massive consumption, Pouteria sapota, were used as precursors for the development of activated carbons (ACs) directed to CO2 adsorption. Chemical activation employing KOH as activating agent and pre-established experimental conditions was applied. Main physicochemical properties of the ACs in relation to their CO2 adsorption performance were examined. The ACs developed from the wood sawdust and the seeds presented specific surfaces areas of 770 and 1000 m2 g−1, respectively, with their porosity development resulting essentially microporous (< 2 nm). They also showed a similar content of acidic surface groups, but basic functionalities of the former duplicated those of the latter. Maximum CO2 adsorbed at equilibrium (273 K and 100 kPa) was 5.0 mmol g−1 and 4.4 mmol g−1 for the samples derived from the sawdust and the seeds, respectively. On the other hand, CO2 adsorption capacities mimicking post-combustion conditions, as evaluated from thermogravimetric assays and breakthrough curves obtained in a packed-bed column, were approximately 1 mmol g−1, indicating a good CO2 adsorption performance for both ACs. Nevertheless, those derived from the wood sawdust with a notorious preeminence of micropores (~ 93%), narrower pore size distribution centered around 1 nm, and a higher content of basic functionalities than the ACs obtained from the seeds showed a relatively better performance. The CO2 removal capacity of the activated carbons was not noticeably affected after five CO2 adsorption–desorption cycles, with both samples almost keeping their initial CO2 adsorption capacity.
        4,000원
        383.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Health-related quality of life (HRQOL) is a construct of quality of life relevant to health. HRQOL can be measured multiple ways including self-perceived interpretation of one’s health status. Research has shown value in understanding self-perceived or person-centered HRQOL. Thus, these types of assessments have been integrated into health care systems, used to help patients set personal goals and to determine treatment success. The purpose of this study was to describe the group, examine the relationship between HRQOL and functional independence, and then determine the impact of standard care on the HRQOL (index and visual analog scale [VAS]). Methods: Retrospective clinical observation study. Descriptive statistics used to describe the stroke sample. Comparison was performed to explore the correlation between the EuroQol 5-Dimensions Questionnaire (EQ-5D) and the Functional Independence Measure (FIM) at admission and discharge. Paired-samples t-test was conducted to evaluate the impact of standard therapy on HRQOL on EQ-5D. Results: n=1325; mean age of 72 years (SD=13.28) and 65% females. A weak, positive correlation found at admission (r=.15, n=1325, p<.000) and discharge (r=.04, n=1325, p<.000). A paired-samples t-test revealed a statistically significant increase in HRQOL index and VAS scores (p’s<.000) overtime, with a large effect size (η2=.74 and .70), respectively. Conclusion: A weak relationship was present between HRQOL and functional independence, thus suggesting these assessments should be used independent of each other. Statistically significant change in scores suggest improvement in HRQOL overtime, supported by large effect sizes and mean scores higher than the minimal important difference range.
        4,000원
        384.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this research work was to know ovarian dynamics and pregnancy rate of cyclic Murrah buffalo cows with induced estrus by administration of prostaglandin F2α (PGF2α) and timed artificial insemination (TAI) with frozen thawed semen. A total of 31 female buffaloes were selected for the study. The buffalos having matured CL observed by ultrasonography were given one intra muscular injection of cloprostenol 500 μg and TAI was performed using frozen thawed semen of Indian Murrah buffalo bull. Results showed that 90.32% (significantly, at p < 0.05) cows explore the sign of heat after injection of PG and 67.85% (significantly, at p < 0.05) cows were become pregnant out of 28 inseminated (TAI) cows. In the 28 inseminated (TAI) cows, average number of smaller and larger size of follicles were non-significantly (p > 0.05) higher at day 3 post PG injection, but the medium size of follicles was non-significantly (p > 0.05) higher at PG injection. At day 3 post PG injection the diameter of follicles was significantly (p < 0.05) higher, but the diameter of CL was significantly (p < 0.01) lower compared at PG injection. At PG injection the diameter of largest follicle was non-significantly differences (p > 0.05) in between pregnant and non-pregnant cows. But at day 3 post PG injection it was significantly (p < 0.01) higher in pregnant cows compared to non-pregnant cows. The number of small, medium, and large follicles at PG injection and at day 3 post PG injection were non-significantly (p > 0.05) difference in between pregnant and non-pregnant buffalo cows. Finally, it is concluded that the CL was effectively regresses and induced the sign of heat in buffalo cows and after AI the cows were become pregnant with significant rate. The study will help to the veterinarian and researcher to know the efficacy of PG injection and AI for reproductive efficiency in buffalo cows.
        4,000원
        385.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The experiment was undertaken to measure the potential impact of animal welfare on the pork quality under two different farming systems: C1 and C2, two conventional farms; W, an animal welfare farm. Ten pigs (Landrace × Yorkshire × Duroc) of live weight 110 kg were randomly selected from each treatment, and slaughtered under uniform conditions. The left loins were collected, and subsequently analyzed for proximate composition, meat quality traits, fatty acids, free amino acids, and antioxidative dipeptides. Pork from the welfare farm (W) had greater back-fat depth and fat content, but the values were not significantly different from C1 or C2. The W loins had significantly lower moisture contents and pH values compared to C1 or C2. The C2 loins showed highest contents of unsaturated fatty acids, whereas C1 had higher polyunsaturated fatty acids as compared to W. The treatments did not show any significant differences in the contents of free aspartic acid. Anserine (an antioxidant dipeptide) from the W loins was significantly lower than that from the conventional farms. The results indicate that pork quality characteristics from animal welfare-farmed pigs were not different from those of conventional farms. Therefore, it would be appropriate to evaluate the industrial value of animal welfare livestock only at the stage of pig production, rather than the meat quality of pork.
        4,500원
        386.
        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
        387.
        2020.03 구독 인증기관 무료, 개인회원 유료
        Anecdotal reports indicate that maladaptive patterns of Internet use constitute behavioral addiction. Internet addiction is characterized by unrestrained and awfully controlled engrossment or behaviors regarding internet access that lead to impairment, stress, dimensionally measured depression, indicators of social separation and anguish. By reviewing and analyzing approximately 100 articles we present evidence that are able to provide an overview of the main themes and proclivity covered by existing and relevant studies. The vital detection of this research unveils that many factors related to social, demographic, lifestyle changes related constructs have a bearing on the phenomenon of internet addiction strongly. This study not only reached certain conclusions for both theory and practice, but also defined future lines of research according to the gaps detected by the study’s results. The main findings from this literature, though not conclusive, but will help the researcher and policymakers to obtain a better understanding and description of the problem faced by the youth and necessary to develop some remedies to lessen the addiction phenomenon.
        4,000원
        388.
        2020.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        At q = 1.81 ± 0.20 × 10-5, KMT-2018-BLG-0029Lb has the lowest planet-host mass ratio q of any microlensing planet to date by more than a factor of two. Hence, it is the first planet that probes below the apparent "pile-up" at q = 5-10 ×10-5. The event was observed by Spitzer, yielding a microlens-parallax πE measurement. Combined with a measurement of the Einstein radius θE from finite-source effects during the caustic crossings, these measurements imply masses of the host Mhost = 1.14+0.10-0.12 M⊙ and planet Mplanet = 7.59+0.75-0.69 M⊕, system distance DL = 3.38+0.22-0.26 kpc and projected separation a⊥ = 4.27+0.21-0.23 AU. The blended light, which is substantially brighter than the microlensed source, is plausibly due to the lens and could be observed at high resolution immediately.
        5,200원
        389.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study presented in the article is focused on use of graphene obtained by novel microwave-enhanced chemical vapor deposition (MECVD) method as a construction material for 3D porous structures—aerogels and sponges. MECVD graphene nanoplatelets-based aerogels were obtained by mixing MECVD graphene nanoplatelets and chitosan, dissolved in 3% acetic acid followed by its freeze drying and carbonization at 800° in inert medium. Surface morphology of aerogels was characterized by SEM. MECVD graphene nanoplatelets-based aerogels are characterized by a porous structure; they are superhydrophobic and possess high sorption capacity with regard to organic liquids of different densities. Polyurethane sponges coated with MECVD graphene can serve as an alternative to aerogels. The process of their obtaining is cheaper and less complicated. They were obtained by facile “dip-coating” method, modifying its surface to increase its hydrophobicity. The resulting sponges are superhydrophobic and superoleophilic, and demonstrate high rate of sorption of organic liquids and can be easily regenerated by squeezing. In addition, they can be used as a separating material in conjunction with vacuum system for continuous and selective collection of organic liquids from the surface of water.
        4,300원
        390.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, we report graphene composite membranes prepared by transfer of a layer of chemical vapor deposition graphene onto porous anodic alumina (AA) substrates with nominal pore size 20 and 30 nm, referred as 20AA and 30AA. The coated and uncoated substrates were characterized using optical and electron microscopy techniques. The bare substrates exhibited a smooth surfaces with a well-organized array of hexagonal pores, displaying an average pore size of 17 ± 3 (20AA) and 23 ± 3 nm (30AA). The scanning electron microscopy and atomic force microscopy analyses confirmed the successful transfer of graphene layer onto the target substrates. The molecular transport study was performed by introducing 0.5 M potassium chloride (KCl) and deionized water in a Side-bi-Side Franz diffusion cell. The graphene/20AA specimen blocked 66% ions transport, and graphene/30AA membrane about 64%. The ions blockage exceeded 90%, near the characteristics of defectfree graphene when the defects of the transferred graphene were sealed with Nylon 6,6. The results of this study suggest the potential use of graphene on AA substrates for water desalination and gas purification applications.
        4,200원
        394.
        2019.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        New triple tungstate phosphors NaPbLa(WO4)3:Yb3+/Ho3+ (x = Yb3+/Ho3+ = 7, 8, 9, 10) are successfully fabricated by microwave assisted sol-gel synthesis and their structural and frequency upconversion (UC) characteristics are investigated. The compounds crystallized in the tetragonal space group I41/a and the NaPbLa(WO4)3 host have unit cell parameters a = 5.3927(1) and c = 11.7961(3) Å, V = 343.05(2) Å3, Z = 4. Under excitation at 980 nm, the phosphors have yellowish green emissions, which are derived from the intense 5S2/ 5F4 → 5I8 transitions of Ho3+ ions in the green spectral range and strong 5F5 → 5I8 transitions in the red spectral range. The optimal Yb3+:Ho3+ ratio is revealed to be x = 9, which is attributed to the quenching effect of Ho3+ ions, as indicated by the composition dependence. The UC characteristics are evaluated in detail under consideration of the pump power dependence and Commission Internationale de L'Eclairage chromaticity. The spectroscopic features of Raman spectra are discussed in terms of the superposition of Ho3+ luminescence and vibrational lines. The possibility of controlling the spectral distribution of UC luminescence by the chemical content of tungstate hosts is demonstrated.
        4,000원
        395.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A new discrete bis-dithiolene complex, [ PPh4]2[Zn(DMED)2] (1; DMED = 1,2-dicarbomethoxy-1,2-dithiolate) with sulfurbased radical character was synthesized and structurally characterized. Complex 1 is stable and exhibits a square planar geometry around the zinc metal. 1 forms nanospheres through a one-pot water-induced self-assembly in a mixture of solvents (acetonitrile–water). These nanospheres were further decorated with water-soluble carbon nanotubes (wsCNTs) through hydrogen bonding between the peripheral –COOCH3 groups of 1 and surfacial carboxyl groups of wsCNTs to assemble into a spherical nanocomposite. The as-prepared nanocomposite showed fluorescence emissions in visible region due to the separation of energy states of the nanospheres assisted by wsCNTs, suggesting the future possibilities of these new materials for use in biomedical application.
        4,000원
        396.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nanoporous carbon/MnO2 (C–MnO2) composites with foam-like structure based on modified nitrile butadiene rubber were achieved by thermal treatment, followed by alkaline solution etching and dipping method. The XRD, nitrogen adsorption and desorption, and SEM and TEM were used to characterize the microstructure of the obtained C–SiO2, C and C–MnO2. Finally, all the obtained samples have been used in three-electrode system to study the electrochemical properties including cyclic voltammetry, galvanostatic charge/discharge and AC impedance for supercapacitor. The study found that the specific capacity of C–MnO2 electrode material for supercapacitor could reach as high as 109 F/g under the current density of 0.5 A/g, which is much higher than those of the other two. These superior electrochemical properties are attributed to the synergistic effect MnO2 particles with the C matrix which functions as a conductive support.
        4,000원
        397.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of the current study was to examine the role of information on shapewear’s functionality in consumers’ purchase decisions in an online shopping context. Through two steps of stimulus development process, four mock websites were developed to conduct a main study. In the main study, a 2 (visual information: absent vs. present images of the shapewear’s functionality) x 2 (verbal information: absent vs. present descriptions of the shapewear’s functionality) between-subject factorial design was employed to examine the impact of visual and verbal information regarding the functionality of shapewear on the consumer decision-making process (i.e., attitudes and purchase intentions). The results showed that verbal information about how shapewear reduces the size of specific body parts (i.e., waist, abdomen, hips, and thighs) were effective in increasing perceived attractiveness in an online context, which increased attitudes and purchase intentions. In addition, attitudes toward the shapewear mediated the effects of expected physical attractiveness on purchase intentions. The results of this study provided empirical support for the importance of expected physical attractiveness in consumers’ online purchase decision on shapewear and useful managerial implications for enhancing the effectiveness of online shapewear presentations by including descriptions of the functionality of shapewear in decreasing the size of body parts.
        4,600원
        398.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        사람이 섭취하는 식품 내의 항생제, 알레르기 유발 물질, 병원균 및 기타 오염물질의 수준을 모니터링하기 위해서는, 빠르고 정확하며 저렴한 비용으로 테스트 해야 한다. 이러한 문제 중 일부를 해결하기 위해 지난 10-15년 동안 진보된 기술(label-free biosensor assays)이 개발되어 왔다. 이 면역감지키트들은 실시간 측정이 가능하고, 높은 수준의 자동화를 제공하며, 향상된 처리율과 민감도를 가지고 있다. 또한, 기존의 방법과 비교하여 가격이 저렴하고, 덜 복잡하며, 분석 시간을 단축시켜주는 사용자 친화 적 키트이다. 이 리뷰에서는 면역감지키트의 장단점, 그리고 미래의 식품안전검사에서의 사용성에 관한 것에 대해 논의해 볼 것이다.
        4,000원
        399.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 할랄 시장의 규모는 매우 커지고 있으며, 전세계적으로 연구 및 발전되어야되는 가장 진보된 사업 중 하나로 주목 받고 있다. 이러한 배경으로 한국과 같은 무슬림 소수 국가들은 지역 경제를 활성화하기 위해 할랄 식품 산업에 진출하여 주도권을 잡으려는 계획을 진행하고 있다. 하지만 할랄 산업 연구에 대한 중요성과 학술 자원에 제한적인 가용성으로 인한 지식 격차는 여전히 남아 있는 실정이다. 본 연구는 할랄 식품 소비자의 구매행동을 고려하여 점점 증가하고 있는 할랄 시장 규모에 대한 정부의 진행방향에 도움을 줄 수 있는 할랄 연구의 기초 자료로 활용될 수 있다. 이를 위해 본 연구의 목적은 한국의 무슬림 소비자들 할랄 식품 구매 의도에 영향을 줄 수 있는 요인 조사를 목적으로 하였다. 본 연구를 위해 477명의 설문참여자를 통해 데이터를 수집하였으며, 한국의 행정구역에서 설문참여자를 모으기 위해 목적표본추출법이 사용 되었다. 이 연구의 가설 결과는 할랄 인증, 종교적 신념 및 할랄 브랜드 등 이 세가지 변수가 무슬림 소비자들 사이에서 할랄 구매 의도와 크게 관련이 있음을 확인하는 것이다. 본 연구의 결과는 제조업체들이 무슬림 소비자들의 할랄 구매 의도를 이해하는데 유용할 뿐만 아니라 소비자들이 일상 생활에서 할랄의 의미를 인지하는데 도움이 될 것으로 예상된다.
        4,500원
        400.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study was conducted to evaluate the seminal attributes and cryo-banking of Achhami (Bos indicus) bull semen. Of two Achhami bulls, 8 ejaculates from each bull were evaluated for seminal attributes. For semen freezing and cryo-banking, 4 ejaculates (having ≥2 mL semen volume, ≥75% of sperm motility and ≥1,000 × 106 cells/mL of sperm concentration) from each bull were used. Semen samples were diluted in egg-yolk-tris-citrate extender using a two-step dilution protocol, and were frozen in liquid nitrogen (LN2) vapour in a styrofoam box. The mean semen volume, colour, sperm mass activity, motility, viability, concentration, abnormal acrosome, midpiece and tail and, abnormal head of two Achhami bulls were 4.4 ± 0.5 mL vs. 2.5 ± 0.2 mL, 2.5 ± 0.1 vs. 2.4 ± 0.1, 3.5 ± 0.1 vs. 3.5 ± 0.1, 77.0 ± 1.1% vs. 78.3 ± 1.3%, 94.4 ± 0.5% vs. 91.0 ± 0.6%, 1137.7 ± 73.7 × 106 cells/mL vs. 1060.0 ± 44.3 × 106 cells/mL, 10.2 ± 0.5% vs. 10.3 ± 0.5% and 6.7 ± 0.5% vs. 8.2 ± 0.3%, respectively. The post-thawed sperm motility and viability were 53.0 ± 2.0% vs. 50.0 ± 0.0% and 80.2 ± 0.4% vs. 73.2 ± 0.7%, while evaluating by computer-assisted sperm analysis (CASA) system, the percentage of the progressive motility, fast motility, slow motility, local motility and immotile sperm were 75%, 68%, 7.4%, 16.6% and 8.6%, respectively. A total number of 620 doses semen straw were cryo-banked. Due to the acceptable post-thawed sperm motility and viability recorded, cryopreservation of Achhami semen is hereby recommended so as to preserve the Achhami breed. For further validation, the fertility will be observed from the produced frozen semen.
        4,000원