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        검색결과 79

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hybrid nanocomposites of aluminium (NHAMMCs) made from AA5052 are fabricated via stir casting route by reinforcing 12 wt% Si3N4 and 0.5 wt% of graphene for usage in aeronautical and automotive applications due to the lower density and higher strength to weight proportion. The wear characteristics of the NHAMMCs are evaluated for different axial load, rotational speed, sliding distance and sliding time based on Box-Behnken design (BBD) of response surface methodology (RSM). Orowan strengthening mechanism is identified from optical image which improves the strength of the composite. Outcomes show that with higher axial load and rotational speed, there is substantial increase in wear loss whereas with increased sliding distance and sliding time there is no considerable increase in wear loss due to the lubricating nature of the reinforced graphene particles since it has higher surface area to volume ratio. Besides, artificial intelligence approach of neuro-fuzzy (ANFIS) model is developed to predict the output responses and the results are compared with the regression model predictions. Prediction from ANFIS outplays the regression model prediction.
        6,400원
        2.
        2023.07 구독 인증기관·개인회원 무료
        We study retailer app use and shopping behavior by investigating whether and how app adopters’ preferred store registration (PSR), a voluntary enrollment of store loyalty program, can lead to changes in purchase behaviors among the adopters in offline stores. A panel dataset from a large bakery franchise chain was studied using difference-in-differences with propensity score matching for causal inference. The results show that customers who participated in PSR increase their spending, compared to customers who did not. In addition, the results confirm that the PSR-spending relationship is moderated by customer and store characteristics; customers who visited infrequently and spent less prior to PSR participation increase their purchases, and they spend more at stores with better service quality.
        3.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Medicinal plant-derived carbon dots are eco-friendly and possess therapeutic properties. Among the medicinal plants studied throughout the world, Centella asiatica (L.) Urb. is known for its medicinal values, especially its neuroceutical and cogniceutical properties. This work discusses the green synthesis of carbon dots (CDs) using C. asiatica leaves as the carbon source via fast and cost-effective microwave-assisted method, and its physico-chemical characterization via UV–visible, fluorescence and FTIR spectrometry, XRD, SEM, AFM, TEM, SAED, EDX and zeta potential analyses. The study revealed quasi-spherical CDs having size ~ 3–6 nm, polycrystalline nature, and presence of various functional groups like –COOH, –H, =CH2 and C–O–C with UV absorption peaks at 213 and 322 nm. Interestingly, the C. asiatica-derived CDs exhibited blue fluorescence under UV with maximum emission wavelength of 460 nm when excited at 400 nm. Further, these CDs were evaluated for their biological applications, which uncovered their potential in therapeutics such as antimicrobial properties against both Gram-positive and Gram-negative bacteria at a dose of 10 μg, strong antioxidant activity with IC50 values of 165.28 and 128.48 μg mL− 1 in DPPH and H2O2 assays, respectively, and profound anti-inflammatory activity with IC50 value of 106.20 μg mL− 1 in protein denaturation assay. The CDs were also assessed for cytotoxicity using whole blood cells and were found to be safe for in vitro administration. Thus, the C. asiatica-derived CDs can be exploited for their potent biomedicinal properties. Fluorescent carbon dots (CDs) were prepared by microwave-assisted pyrolysis of Centella asiatica leaf extract and purification. The as synthesized CDs were subjected to various physico-chemical characterization and biomedical assays to understand its properties.
        4,800원
        5.
        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
        8.
        2018.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present the analysis of KMT-2016-BLG-0212, a low flux-variation (Iflux−var ∼ 20 mag) microlensing event, which is in a high-cadence (Γ = 4hr −1) field of the three-telescope Korea Microlensing Telescope Network (KMTNet) survey. The event shows a short anomaly that is incompletely covered due to the brief visibility intervals that characterize the early microlensing season when the anomaly occurred. We show that the data are consistent with two classes of solutions, characterized respectively by low-mass brown-dwarf (q = 0.037) and sub-Neptune (q < 10−4) companions. Future high-resolution imaging should easily distinguish between these solutions.
        4,000원
        10.
        2018.07 구독 인증기관·개인회원 무료
        Despite growing research interest in consumer health, well-being and beauty, little is known about factors influencing consumer purchase decisions for female fitness devices. This study focuses on Kegel exercises – exercise routines developed by Dr. Kegel to strengthen pelvic floor muscles – that are recommended by health professionals for patients experiencing health ailments such as urinary incontinence, sexual dysfunction, and dissatisfaction. Despite the benefits, women are not well aware of the role of pelvic floor muscles. The diffusion and acceptance of Kegel exercise and devices among women are likely determined by how comfortable women are about obtaining such benefits. For this reason, feminism should play an important role in shaping women’s desire to engage in Kegel exercises. Thus, this research investigates how feminism is related to Millennial women’s engagement with fitness products, particularly Kegel devices. Drawing on the literatures about sexuality, health, and marketing, we propose that feminism positively influences women’s health-related attitudes (i.e., attitudes towards fitness, fitness opinion leadership, attitude toward core strength, and desire to control sex life), which in turn positively impacts women’s fitness engagement. Fitness engagement, in turn, is expected to predict attitudes towards Kegel exercise and Kegel device purchase intentions. On the other hand, women’s attitudes toward core strength and desire to control sex life are proposed to have a direct, positive impact on attitude towards Kegel exercise. Analysis of PLS-SEM shows general support for the hypotheses. We discuss how interest in Kegel devices could, in turn, lead to positive effects on overall physical and psychological health and provide implications for marketing practitioners.
        18.
        2016.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We report the characterization of a massive (mp = 3:91:4Mjup) microlensing planet (OGLE- 2015-BLG-0954Lb) orbiting an M dwarf host (M = 0:33  0:12M ) at a distance toward the Galactic bulge of 0:6+0:4 􀀀0:2 kpc, which is extremely nearby by microlensing standards. The planet-host projected separation is a?  1:2AU. The characterization was made possible by the wide- eld (4 deg2) high cadence (􀀀 = 6 hr􀀀1) monitoring of the Korea Microlensing Telescope Network (KMTNet), which had two of its three telescopes in commissioning operations at the time of the planetary anomaly. The source crossing time t = 16 min is among the shortest ever published. The high-cadence, wide- eld observations that are the hallmark of KMTNet are the only way to routinely capture such short crossings. High-cadence resolution of short caustic crossings will preferentially lead to mass and distance measurements for the lens. This is because the short crossing time typically implies a nearby lens, which enables the measurement of additional e ects (bright lens and/or microlens parallax). When combined with the measured crossing time, these e ects can yield planet/host masses and distance.
        4,000원
        19.
        2016.04 구독 인증기관·개인회원 무료
        The penetration-enhancing effect of a binary mixture of rosemary essential oil constituents, and its correlation to increased toxicity were investigated. GC-MS analyses revealed that the major constituents of rosemary essential oil were 1,8-cineole and camphor, and a binary mixture of them showed synergistic insecticidal activity via topical application in third instar larvae of the cabbage looper, Trichoplusia ni. In the mixture, penetration of camphor was significantly enhanced both in vivo and in vitro, whereas that of 1,8-cineole did not change much compared to individual application. Injection into hemocoel of fifth instar larvae indicated that camphor was more toxic than 1,8-cineole, although it was less toxic than 1,8-cineole when applied topically. A possible mechanism for enhanced penetration of camphor by 1,8-cineole is reduced surface tension of the mixture. Contact angles of 50% acetonic solutions on a layer of beeswax showed that the surface tension of 1,8-cineole was lower than that of camphor. Another probable reason is a change of camphor from solid to liquid status, when mixed with 1,8-cineole. This is the first report attempting to explain the synergistic insecticidal interaction of essential oil components, from a physiochemical perspective.
        20.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Most of the stars in the Galaxy are in binary systems. Binaries should be possible as the hosting stars of planets. Searching for planetary companions to binaries, especially evolved close binary stars, can provide insight into the formation and the ultimate fate of circumbinary planets and shed light on the late evolution of binary stars. In order to do this, we have chosen some post common envelope binaries including sdB-type eclipsing binaries and detached WD+dM eclipsing binaries as our targets and monitored them for several years. In this paper, we will present some of our new observations and results for three targets, NSVS 07826147, NSVS14256825 and RR Cae.
        3,000원
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