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        검색결과 5

        1.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Activated carbon (AC) is a versatile and extensively employed adsorbent in environmental remediation. It possesses distinct properties that can be enhanced to selectively target specific pollutants through modifications, including chemical impregnation or incorporation into composite materials. In this study, porous calcium alginate beads (PCAB) were synthesized by incorporating AC and natural alginate through ion gelation in a Ca(II) ion-containing solution, with the addition of sodium lauryl sulfate as a surfactant. The prepared PCAB was tested for Cu(II) removal. PCAB exhibited a spherical shape with higher porosity and surface area (160.19 m2. g−1) compared to calcium alginate beads (CAB) (0.04 m2. g−1). The adsorption kinetics followed the pseudo-first-order model for PCAB and the pseudo-second-order model for CAB. The Langmuir isotherm model provided the best fit for adsorption on PCAB, while the Freundlich model was suitable for CAB. Notably, PCAB demonstrated a maximum adsorption capacity of 75.54 mg.g−1, significantly higher than CAB's capacity of 9.16 mg. g−1. Desorption studies demonstrated that 0.1 M CaCl2 exhibited the highest efficiency (90%) in desorbing Cu(II) ions from PCAB, followed by 0.1 M HCl and 0.1 M NaCl. PCAB showed efficient reusability for up to four consecutive adsorption– desorption cycles. The fixed-bed column experiment confirmed the match with the Thomas model to the breakthrough curves with qTH of 120.12 mg.g−1 and 68.03 mg.g−1 at a flow rate of 1 mL.min−1 and 2 mL.min−1, respectively. This study indicated that PCAB could be an effective adsorbent for Cu(II) removal, offering insights for further application and design considerations.
        4,600원
        2.
        2018.07 구독 인증기관·개인회원 무료
        By increasing awareness of product offers and availability in the consumer’s proximity, Location Based Marketing (LBM) increases relevance of placed advertisements. However, depending on how it is executed, such advertising can also be perceived as intrusive, irritating, or even violating consumer’s privacy. Existing knowledge does not offer clear directions for retailers, who are keen to know of LBM’s effectiveness on sales. In this paper, authors investigate the effects of LBM on application (app) driven revenues of 116 major mobile retailers from around the globe. In particular, we examine the contingency effects of the roles of device as well as privacy needs of the brand audience. Findings reveal that effects of LBM on app-based revenues vary by tactic (inbound vs. outbound), type of device (Tablet vs. Phone), and user type based on brand of app (Android vs. Apple). Overall, this research identifies critical factors for retailers to consider, in order to best monetize their location based efforts. Contributions of the analysis and managerial implications are discussed.
        3.
        2005.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Using 13.7 m telescope of Qinghai station of NAO, PMO at Delin Ha, 43 IRAS sources were mapped with 13CO J=1-0 C18O J=1-0 and CO J=1-0. Each source has one or more cores. The distances of these cores range from 1 pc to several pc, and the masses from 102M⊙ to 105M⊙. High velocity outflows were detected. The mass, momentum and energy of these massive cores are larger than those of the low mass ones. With radio, IRAS, MSX data, stellar source distribution were investigated, and sourceless cores that deviate from infrared sources were identified. They are potential high mass star formation sites.
        3,000원
        5.
        2003.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        There are at least three effects of the non-thermal particle bombardment on the solar atmosphere: (1) non-thermal ionization and excitation; (2) proton-hydrogen charge exchange; (3) impact line polarization. Due to the non-thermal ionization and excitation effects of electron bombardments in flares, Hα line is widely broadened and shows a strong central reversal. Significant enhancements at the line wings of Lyα and Lyβ are also predicted. In the case of proton bombardment, less strong broadening and no large central reversal are expected. However, due to proton-hydrogen charge exchange, the enhancements at the red wings of Lyα and especially of Lyβ lines at the early impulsive phase of flares are significant. Electron beam can also in some cases generates visible and UV continuum emission in white-light flares. However, at the onset phase, a negative 'black' flare may appear in several seconds, due to the increase of the H- opacity. The impact polarization of atomic lines can provide complementary information on the energetic particles, the energy transport and deposit in the solar chromosphere. New results of spectropolarimetric analysis for the major flare on July 23, 2002 are also given in the paper.
        4,000원