238 research outputs found

    Thermal conductivity of suspended pristine graphene measured by Raman spectroscopy

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    The thermal conductivity of suspended single-layer graphene was measured as a function of temperature using Raman scattering spectroscopy on clean samples prepared directly on a prepatterned substrate by mechanical exfoliation without chemical treatments. The temperature at the laser spot was monitored by the frequency of the Raman 2DD band of the Raman scattering spectrum, and the thermal conductivity was deduced by analyzing heat diffusion equations assuming that the substrate is a heat sink at ambient temperature. The obtained thermal conductivity values range from ∌\sim1800 Wm−1^{-1}K−1^{-1} near 325 K to ∌\sim710 Wm−1^{-1}K−1^{-1} at 500 K.Comment: 4pages, 3 figure

    Post Data Breach Use of Protective Technologies: An Examination of Users’ Dilemma

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    This preliminary research addresses the technology use uncertainties that arise when users are presented with protective technologies following a data breach or privacy violation announcement. Prior studies have provided understanding of determinants of technology use through several perspectives. The study complements prior research by arguing that, beyond individual dispositions or technology features, data breach announcements bring users’ focus on the actions of the breaching organization. Fair process and information practices provide avenue for organizations to alleviate users’ concerns and increase service usage. We draw on organizational justice theory to develop a model that explicates the effect of organizational fairness process and use of technologies. We test this model using data from 200 Facebook users recruited from Amazon MTurk. We found that procedural and informational justice have differential effect on users’ desire to use protective technologies. Our findings have both theoretical and practical implications

    Investigation on marine LNG propulsion systems for LNG carriers through an enhanced hybrid decision making model

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    Since the use of LNG as an alternative fuel has drawn increasing attention from the marine industry, this paper aimed to evaluate three competitive LNG fuelled engine systems: ultra-steam turbine, four-stroke medium speed engine, and two-stroke low-speed engine systems. To achieve this goal, the paper developed an enhanced hybrid decision-making model which was applied to integrate the economic, environmental and technical performance of these systems. This model can be represented as a semi-quantitative multi-criteria decision making process in combination of several novel techniques, particularly ‘life cycle cost assessment’ for economic analysis, ‘life cycle assessments’ for environmental analysis, ‘fuzzy order preference by similarity to ideal solution’ for technical analysis and ‘fuzzy analytic hierarchy process’ for multi-criteria decision making. A case study with a 174K LNG carrier has revealed that the two-stroke low-speed engine system is the most effective overall and suggested that this type of engine system will hold the lead over the other candidates in the large LNG carrier market. It has also demonstrated the effectiveness of the proposed model to improve the inherent subjectivity in existing qualitative multi-criteria decision-making processes by guiding the overall process in a more objective direction. Finally, this paper has revealed an underlying novelty of the proposed model to enhance the level of confidence level in the decision by expanding our short-term perspective to the holistic one

    Revisiting the Concept of Targeting NFAT to Control T Cell Immunity and Autoimmune Diseases

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    The nuclear factor of activated T cells (NFAT) family of transcription factors, which includes NFAT1, NFAT2, and NFAT4, are well-known to play important roles in T cell activation. Most of NFAT proteins are controlled by calcium influx upon T cell receptor and costimulatory signaling results increase of IL-2 and IL-2 receptor. NFAT3 however is not shown to be expressed in T cells and NFAT5 has not much highlighted in T cell functions yet. Recent studies demonstrate that the NFAT family proteins involve in function of lineage-specific transcription factors during differentiation of T helper 1 (Th1), Th2, Th17, regulatory T (Treg), and follicular helper T cells (Tfh). They have been studied to make physical interaction with the other transcription factors like GATA3 or Foxp3 and they also regulate Th cell signature gene expressions by direct binding on promotor region of target genes. From last decades, NFAT functions in T cells have been targeted to develop immune modulatory drugs for controlling T cell immunity in autoimmune diseases like cyclosporine A, FK506, etc. Due to their undesirable side defects, only limited application is available in human diseases. This review focuses on the recent advances in development of NFAT targeting drug as well as our understanding of each NFAT family protein in T cell biology. We also discuss updated detail molecular mechanism of NFAT functions in T cells, which would lead us to suggest an idea for developing specific NFAT inhibitors as a therapeutic drug for autoimmune diseases
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