238 research outputs found
Thermal conductivity of suspended pristine graphene measured by Raman spectroscopy
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 2 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 1800 WmK near 325 K to
710 WmK at 500 K.Comment: 4pages, 3 figure
Post Data Breach Use of Protective Technologies: An Examination of Usersâ Dilemma
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 usersâ focus on the actions of the breaching organization. Fair process and information practices provide avenue for organizations to alleviate usersâ 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 usersâ 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
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 âlife cycle cost assessmentâ for economic analysis, âlife cycle assessmentsâ for environmental analysis, âfuzzy order preference by similarity to ideal solutionâ for technical analysis and âfuzzy analytic hierarchy processâ 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
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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