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        검색결과 316

        42.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Multiwall carbon nanotubes (MWCNT) with two different (L/D) aspect ratios (7±2 μm/140±30 nm and 0.5–2 μm/8–15 nm) were surface treated using nitric acid (HNO3) and polyethyleneimine (PEI) prior to their deposition on carbon fibers (CF). Before the hierarchical reinforcement with CF-MWCNT, the CFs were treated with 3-glycidoxypropyltrimethoxysilane, a coupling agent (Z6040) and with poly(amidoamine) (PAMAM) a dendrimer containing an ethylenediamine core and amine surface groups. The MWCNT were deposited on the CF using two methods, by electrostatic attraction and by chemical reactions. The changes in the CF surface morphology after the MWCNT deposition were analyzed using SEM, which revealed a higher density and uniform coverage for the PAMAM-treated CF and the short MWCNTs. The interfacial adhesion of the composite materials was evaluated using the single fiber fragmentation technique. The results indicated an improvement in the interfacial shear strength with the addition of the short-MWCNTs treated with acid solutions and grafted onto the surface of the CF fiber using electrostatic attraction.
        4,000원
        43.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We present a summary of our spectroscopic redshift catalogue of 404 sources in the AKARI Deep Field South (ADF-S). We have used the AAOmega spectrograph to target mid-infrared and far-infrared sources selected primarily from AKARI observations in this field for which we were able to obtain optical counterparts. Our sources with identified redshifts include 316 with Hα detections at z  0:345 and 15 sources at z > 1 with MgII or Ly emission lines. About 13% of our z  0:345 sources are dominated by active galactic nuclei (AGN) emission, although many show emission from both star formation and AGNs. The median Balmer decrement is 5.9. Ultra-luminous infrared galaxies (ULIRGs) were found only in the higher-redshift sources. Optical and near infrared data will be available shortly, enabling calibration of the line luminosities and spectral energy distribution (SED) tting for these sources.
        4,000원
        47.
        2016.07 구독 인증기관·개인회원 무료
        The past decades showed an increase in the number of meals consumed away from home. Restaurants could therefore play a pivotal role in improve diet quality by offering healthier food on their menus (Glanz and Hoelscher, 2004). One of the instruments that restaurants can use to increase healthier food intake is by making use of portion size. When people are served larger portions, they eat more (Steenhuis & Vermeer, 2009). In this study, we investigate the effectiveness of increased portion sizes of vegetables and lower portion sizes of meat (or fish) in a restaurant setting. Three restaurant locations from a restaurant chain in the Netherlands were selected for a field experiment. A cross-over design was used in which each restaurant was randomly assigned to a sequence of two conditions (i.e., intervention and control condition). In the intervention period, portion sizes of vegetables on plates were doubled (150 grams versus 75 grams) and portion sizes of meat and fish were cut on average with 12.5%. Consumption was calculated by subtracting the residues from the plates from the average served amount. Additionally, p3rticipants received a questionnaire in which a number of questions were asked, i.a., about their satisfaction with the meal and restaurant. In total, 536 participants in the control condition and 470 participants in the experimental condition were obtained. Vegetable consumption was higher in intervention weeks (M = 115.5 grams) than in control weeks (M = 61.7 grams; p < .001). Meat consumption was lower in intervention weeks (M = 183.1 grams) as compared to control weeks (M = 211.1 grams; p < .001). Finally, satisfaction with the restaurant visit did not differ between intervention weeks (M = 4.27) and control weeks (M = 4.35; p > .05). The results are robust given that we found the same effects across the three restaurants. An important implication of this study is that portion sizes could indeed be used as an effective instrument in stimulating healthy consumption behavior without affecting customer’s satisfaction.
        48.
        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
        53.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Galaxies can be "pre-processed" in the low-density outskirts by ambient medium in the filaments or tidal interactions with other galaxies while falling into the cluster. In order to probe how early on and by which mechanisms galaxies can be affected before they enter high-density cluster environments, we are carry- ing out an atomic hydrogen (H i) imaging study of a sample of galaxies selected from three filamentary structures around the Virgo cluster. Our sample consists of 14 late-type galaxies, which are potentially interacting with their surroundings. The Hi observations have been done using the Westerbork Synthesis Radio Telescope, the Giant Metrewave Radio Telescope, and the Jansky Very Large Array with column density sensitivity of ≈ 3-5 X 1019 cm-2 in 3σ per channel, which is low enough to detect faint Hi features in the outer disks of galaxies. In this work, we present the Hi data of two galaxies that were observed with GMRT. We examine the Hi morphology and kinematics to find the evidence for gas-gas and/or tidal interactions, and discuss which mechanism(s) could be responsible for pre-processing in these cases.
        3,000원
        54.
        2015.09 KCI 등재 구독 인증기관·개인회원 무료
        This work considers the elliptic restricted three-body problem under effects of radiation of the bigger primary, and an oblate spheroid for the smaller primary to mimic an exoplanetary system with a gas giant planet. Under the in uences of both effects we look for the existence of the triangular equilibrium points and the in uences of the radiation and oblateness on the locations and motion of the points. We set the system in a normalized rotating coordinate system and derive equations of motion for the third infinitesimal object. Our study shows that the effects modify the equilateral/isosceles triangle shape with respect to the primaries. The triangular points also have non-planar motion with period depending on the value of the planet oblateness.
        55.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Eclipsing Binaries Minima (BIMA) Monitoring Project is a CCD-based photometric observational program initiated by Bosscha Observatory - Lembang, Indonesia in June 2012. Since December 2012 the National Astronomical Research Institute of Thailand (NARIT) has joined the BIMA Project as the main partner. This project aims to build an open-database of eclipsing binary minima and to establish the orbital period of each system and its variations. The project is conducted on the basis of multisite monitoring observations of eclipsing binaries with magnitudes less than 19 mag. Di erential photometry methods have been applied throughout the observations. Data reduction was performed using IRAF. The observations were carried out in BVRI bands using three di erent small telescopes situated in Indonesia, Thailand, and Chile. Computer programs have been developed for calculating the time of minima. To date, more than 140 eclipsing binaries have been observed. From them 71 minima have been determined. We present and discuss the O-C diagrams for some eclipsing binary systems.
        4,000원
        58.
        2014.07 구독 인증기관·개인회원 무료
        While the relationship between market orientation and new product performance has been extensively investigated, the mechanism by which market orientation contributes to new product performance was further studied in a business-to-business context. We developed a set of alternative research models to examine the roles of timing of entry and positional advantage in the market orientation—new product performance relationship. The results showed that industrial firms’ positional advantage is a key step in the process. Market orientation does not directly influence new product performance. Instead, market orientation helps to establish a firms’ positional advantage, which, in turn, positively influences new product performance in the marketplace. Timing of entry, shown to be an outcome of positional advantage, is not a determinant of new product performance in the business-to-business context. The findings revealed that market-oriented firms achieve superior new product performance through thoughtfulness indicated by a well-defined positioning strategy, not rapidity of action.
        59.
        2014.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, synthetic viscose rayon fabric has been used for preparing activated carbon fabric (ACF), impregnated with different concentrations of H3PO4. The effect of H3PO4 im-pregnation on the weight yield, surface area, pore volume, chemical composition and mor-phology of ACF were studied. Experimental results revealed that both Brunauer-Emmett-Teller surface area and micropore volume increased with increasing H3PO4 concentration; however, the weight yield and microporosity (%) decreased. It was observed that samples impregnated at 70°C (AC-70) give higher yield and higher microporosity as compared to 30°C (AC-30). The average pore size of the ACF also gradually increases from 18.2 to 19 and 16.7 to 20.4 Å for 30°C and 70°C, respectively. The pore size distribution of ACF was also studied. It is also concluded that the finalACF strength is dependent on the concentra-tion of impregnant.
        4,000원
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